,illustration3 ,,pierre ,,curie ,,in #aijf4 ,hellog ,dujardin ,dujardin ,imp4 ,ch4 ,wtmann ,,pierre ,,curie ,,by ,,marie ,,curie ,translated by ,,charlotte ,,and ,,vernon ,,kellogg ,,with ,,an ,,introduction ,,by ,,mrs4 ,,william ,,brown ,,meloney ,,and ,,autobiographical ,,notes ,,by ,,marie ,,curie ,,illustrated ,,new ,,york ,,the ,,macmillan ,,company #aibc ,copyright1 #aibc1 ,by ,,marie ,,curie4 ,it is possible to conceive that in criminal hands radium might prove very dangerous1 and the question therefore arises whether it be to the advantage of humanity to know the secrets of nature1 whether we he sufficiently mature to profit by them1 or whether that knowledge may not prove harmful4 ,take1 for instance1 the discoveries of ,nobel--powerful explosives have made it possible for men to achieve admirable things1 but they are also a terrible means of destruction in the hands of those great criminals who draw nations into war4 ,i am among those who believe with ,nobel that humanity will obtain more good than evil from future discoveries4 ,,pierre ,,curie1 ,nobel ,conference1 #aijc4 ,,translators' ,,note ,the translators wish to acknowledge their obligations to ,dr4 ,r4 ,b4 ,moore1 ,chief ,chemist1 ,u4 ,s4 ,bureau of ,mines1 and an ,american authority on radium1 who kindly read the whole translation in manuscript in order to assure its accuracy as to the technical details referred to by ,madame ,curie in her account of the work of her husband and herself on radium4 ,,preface ,it is not without hesitation that ,i have undertaken to write the biography of ,pierre ,curie4 ,i should have preferred confiding this task to some relative or some friend of his infancy who had followed his whole life intimately and possessed as full a knowledge of his earliest years as of those after his marriage4 ,jacques ,curie1 ,pierre's brother and the companion of his youth1 was bound to him by the tenderest affection4 ,but after his appointment to the ,university of ,montpellier1 he lived far from ,pierre1 and he therefore insisted that ,i should write the biography1 believing that no one else better knew and understood the life of his brother4 ,he communicated to me all his personal memories2 and to this important contribution1 which ,i have utilized in full1 ,i have added details related by my husband himself and a few of his friends4 ,thus ,i have reconstituted as best ,i could that part of his existence that ,i did not know directly4 ,i have1 in addition1 tried faithfully to express the profound impression his personality made upon me during the years of our life together4 ,this narrative is1 to be sure1 neither complete nor perfect4 ,i hope1 nevertheless1 that the picture it gives of ,pierre ,curie is not deformed1 and that it will help to conserve his memory4 ,i wish1 too1 that it might remind those who knew him of the reasons for which they loved him4 ,m4 ,c4 ,,contents ,introduction ,,chapter ,i4 ,the ,curie ,family4 ,infancy and ,first ,studies of ,pierre ,curie ,,ii4 ,dreams of ,youth4 ,first ,scientific ,work4 ,discovery of ,piezo-,electricity ,,iii4 ,life as the ,director of ,laboratory ,work in the ,school of ,physics and ,chemistry4 ,generalization of the ,principle of ,symmetry4 ,investigations of ,magnetism ,,iv4 ,marriage and ,organization of ,family ,life4 ,personality and ,character ,v4 ,the ,dream ,become a ,reality4 ,the ,discovery of ,radium ,,vi4 ,the ,struggle for ,means to ,work4 ,the ,burden of ,celebrity4 ,the ,first ,assistance from the ,state4 ,it ,comes ,too ,late ,,vii4 ,the ,nation's ,sorrow4 ,the ,laboratories3 ,sacred ,places ,autobiographical ,notes--,marie ,curie ,,illustrations ,pierre ,curie in #aijf4 ,pierre and ,marie ,curie in their laboratory1 where radium was discovered4 ,a view of the extraction of radium in the old shed where the first radium was obtained4 ,pierre ,curie with the quartz piezo-electroscope he invented1 by which rays of radium are measured4 ,a view of the extraction of radium in the old shed where the first radium was obtained4 ,mme4 ,curie instructing ,american soldiers in her ,paris laboratory4 ,madame ,curie in her laboratory at the ,institut ,curie1 ,paris4 ,mme4 ,curie and ,president ,harding at the ,white ,house1 ,may #bj1 #aiba1 when a gram of radium was presented to its discoverer by the women of ,america4 ,,pierre ,,curie ,,the ,,life ,,story ,,of ,,pierre ,,curie ,,introduction ,,by ,,mrs4 ,,william ,,brown ,,meloney ,every little while a man or a woman is born to serve in some big way4 ,such a one surely is ,marie ,curie4 ,her discovery of radium has advanced science1 relieved human suffering and enriched the world4 ,the spirit in which she has done her work has challenged the minds and souls of men4 ,one morning in the spring of #ahih1 when the ,united ,states was going to war with ,spain1 ,madame ,curie stepped forth from a crude shack on the outskirts of ,paris1 with the greatest secret of the century literally in the palm of her hand4 ,it was one of the silent1 unheralded great moments in the world's history4 ,the discovery which had become a fact that morning was no accident4 ,it was a triumph over hardship and doubting men4 ,it represented years of patient labor4 ,madame ,curie and her husband1 ,pierre ,curie1 had wrested from ,mother ,earth one of her most priceless secrets4 ,i have been asked to tell why ,i undertook the ,marie ,curie ,radium ,campaign and how ,i persuaded ,madame ,curie to write this book4 ,it is with much hesitancy that ,i venture to write a preface to this book4 ,she once chided me1 in her gentle way1 for an article in which ,i had stated facts with some feeling--although the facts praised her4 ,in science1 she said1 we should be interested in things1 not persons4 ,madame ,curie is the most modest of women4 ,it is only after long persuasion that she has consented to record the autobiographical notes contained in this book4 ,still1 so much has been left unsaid1 uninterpreted1 that ,i feel an obligation to say a word toward a fuller understanding of this great and noble character4 ,in #aiae ,i wrote in my editor's suggestion book3 ,greatest woman's story in the world--,marie ,curie1 discoverer of radium4 ,for the next four years scarcely any writer of prominence went abroad without a commission from me to bring back the story of ,madame ,curie4 ,always they returned with the report3 ,she was not to be found1 or ,she was at the front somewhere1 or ,she won't see journalists4 ,my own letters to ,madame ,curie brought no reply4 ,i did not know then that great bags of mail from all parts of the world lay piled up in her laboratory where there was no secretary1 while ,madame ,curie with her ,x-ray apparatus was at the front1 relieving suffering and saving lives4 ,in ,may1 #aiai1 another mission took me to ,paris and ,i resolved to see ,madame ,curie myself4 ,my friend1 ,stphane ,lauzanne1 ,editor-in-,chief of ,le ,matin1 said3 ,give it up4 ,become interested in something else2 she will see no one4 ,she does nothing but work4 ,i began to ask questions4 ,she is very simple and exceedingly retiring1 said ,lauzanne4 ,few things in life are more distasteful to her than publicity4 ,her mind is as exact and logical as science itself4 ,she cannot accept or understand exaggerations and inaccurate quotations4 ,she cannot understand why scientists1 rather than science1 should be discussed in the press4 ,there are but two things for her--her little family and her work4 ,after the death of ,pierre ,curie1 the faculty and officials of the ,university of ,paris decided to depart from all precedent and appoint a woman to a full professorship at the ,sorbonne4 ,madame ,curie accepted the appointment and the date was set for her installation4 ,it was the history-making afternoon of ,october #eth1 #aijf4 ,the members of the class which had formerly been instructed by ,professor ,pierre ,curie were seated in one group4 ,there was present a large crowd--celebrities1 statesmen1 academicians1 all the faculty4 ,suddenly through a small side door entered a woman all in black1 with pale hands and high arched forehead4 ,the magnificent forehead won notice first4 ,it was not merely a woman who stood before us1 but a brain--a living thought4 ,her appearance was enthusiastically applauded for five minutes4 ,when the applause died down1 ,madame ,curie bent forward with slightly trembling lips4 ,we wondered what she was about to say4 ,it was important4 ,it was history1 whatever she said4 ,in the foreground sat a stenographer1 ready to record her words4 ,would she speak of her husband8 ,would she thank the ,minister and the public8 ,no1 she began quite simply as follows3 ',when we consider the progress made by the theories of radio-activity since the beginning of the ,nineteenth ,century--' ,the important thing to this great woman is work4 ,time should not be wasted in idle words4 ,and so1 dispensing with all superficial formality1 with no betrayal of the tremendous emotion which all but overcame her--except by the extreme pallor of her face and the trembling of her lips--she continued her lecture in clear1 well-modulated tones4 ,it was typical of this great soul that she should carry on their work courageously and without faltering4 ,you will see1 concluded ,lauzanne1 it is useless to try to interrupt her work for interviews4 ,later ,i met one of ,madame ,curie's fellow scientists who sympathized with my desire1 but who agreed with ,lauzanne that an interview was impossible4 ,finally1 however1 he promised to carry a letter to ,madame ,curie4 ,i wrote ten letters and destroyed them4 ,in one ,i said3 ,my father1 who was a medical man1 wrote3 ',it is impossible to exaggerate the unimportance of people4' ,but you have been important to me for twenty years1 and ,i want to see you a few minutes4 ,the answer came within an hour4 ,i was to go to the laboratory the next morning4 ,i had been in ,mr4 ,edison's laboratory a few weeks before sailing from home4 ,edison is rich in the material things--as he should be4 ,every kind of equipment is at his command4 ,he is a power in the financial as well as the scientific world4 ,in my childhood ,i had lived near ,alexander ,graham ,bell2 had admired his great house and his fine horses4 ,a short time before1 ,i had been in ,pittsburgh1 where the sky is plumed by the tall smoke stacks of the greatest radium reduction plants in the world4 ,i remembered that millions of dollars had been spent on radium watches and radium gun sights4 ,several millions of dollars' worth of radium was even then stored in various parts of the ,united ,states4 ,i had been prepared to meet a woman of the world1 enriched by her own efforts and established in one of the white palaces of the ,champs d',elyses or some other beautiful boulevard of ,paris4 ,i found a simple woman1 working in an inadequate laboratory and living in a simple apartment on the meager pay of a ,french professor4 ,as ,i entered the new building at ,number ,one ,rue ,pierre ,curie1 which stands out conspicuously among the old walls of the ,university of ,paris1 ,i had already formed a picture of the laboratory of the discoverer of radium4 ,i waited a few minutes in the bare little office which might have been furnished from ,grand ,rapids1 ,michigan4 ,then the door opened and ,i saw a pale1 timid little woman in a black cotton dress1 with the saddest face ,i had ever looked upon4 ,her well-formed hands were rough4 ,i noticed a characteristic1 nervous little habit of rubbing the tips of her fingers over the pad of her thumb in quick succession4 ,i learned later that working with radium had made them numb4 ,her kind1 patient1 beautiful face had the detached expression of a scholar4 ,suddenly ,i felt like an intruder4 ,i was struck dumb4 ,my timidity exceeded her own4 ,i had been a trained interrogator for twenty years1 but ,i could not ask a single question of this gentle woman in a black cotton dress4 ,i tried to explain that ,american women were interested in her great work1 and found myself apologizing for intruding upon her precious time4 ,to put me at my ease1 ,madame ,curie began to talk about ,america4 ,she had for many years wanted to visit my country1 but she could not be separated from her children4 ,america1 she said1 has about fifty grammes of radium4 ,four of these are in ,baltimore1 six in ,denver1 seven in ,new ,york4 ,she went on naming the location of every grain4 ,and in ,france8 ,i asked4 ,my laboratory1 she replied simply1 has hardly more than a gramme4 ,you have only a gramme8 ,i exclaimed4 ,that meant less than one-twenty-ninth of an ounce4 ,i8 ,oh1 ,i have none1 she corrected4 ,it belongs to my laboratory4 ,i suggested royalties on her patents4 ,surely she had protected her right to the processes by which radium is produced4 ,the revenue from such patents should have made her a very rich woman4 ,quietly1 and without any seeming consciousness of the tremendous renunciation1 she said1 ,there were no patents4 ,we were working in the interests of science4 ,radium was not to enrich any one4 ,radium is an element4 ,it belongs to all people4 ,she had contributed to the progress of science and the relief of human suffering1 and yet1 in the prime of her life she was without the tools which would enable her to make further contribution of her genius4 ,if you had the whole world to choose from1 ,i asked impulsively1 what would you take8 ,it was a silly question1 perhaps1 but as it happened1 a fateful one4 ,you ought to have everything in the world you need to go on with your work1 ,i said4 ,some one must undertake this4 ,who will8 she asked rather hopelessly4 ,the women of ,america1 ,i promised--and then ,i rose to go4 ,that week ,i learned that the market price of a gramme of radium was one hundred thousand dollars4 ,i also learned that ,madame ,curie's laboratory1 although practically a new building1 was without sufficient equipment2 that the radium held there was used at that time only for extracting emanations for hospital use in cancer treatment4 ,i saw ,madame ,curie at the ,institute again and then in her own home--a small apartment in the ,ile ,st4 ,louis1 where she lived with her two daughters4 ,it was a happy1 busy little family4 ,they had no protest against life except to regret that lack of equipment interfered with the important research work ,madame ,curie and her daughter1 ,irene1 should have been doing4 ,it was my hope when ,i arrived in ,new ,york1 a few weeks afterwards1 to find ten women to subscribe ten thousand dollars each for the purchase of a gramme of radium1 and in this way to enable ,madame ,curie to go on with her work1 without the publicity of a general campaign4 ,that hope was soon dashed4 ,i found one or two such women1 but not ten4 ,there were not ten to buy that gramme of radium but there were a hundred thousand women and a group of men to help1 who determined the money must be raised4 ,my first direct and substantial support came from ,mrs4 ,william ,vaughn ,moody1 widow of the ,american poet and playwright4 ,when we found it would be necessary to launch a national campaign1 ,mrs4 ,robert ,g4 ,mead1 a doctor's daughter1 and one who had been a standby in cancer prevention work1 became secretary1 and ,mrs4 ,nicholas ,f4 ,brady an executive member of the committee4 ,behind these women stood a group of scientific men1 who knew what radium had meant to humanity1 among them ,dr4 ,robert ,abbe1 the first ,american surgeon to use radium1 and ,dr4 ,francis ,carter ,wood4 ,in less than a year the fund had been raised4 ,stphane ,lauzanne describes a second impressive moment in the life of ,madame ,curie4 ,it was nearly a year after my talk with her4 ,it was fifteen years since that scene at the ,university of ,paris4 ,these years had been spent in her laboratory2 she had made no public appearance4 ,it was in ,march1 #aiba1 that ,monsieur ,lauzanne heard her voice again4 ,i lifted the telephone receiver1 he relates1 and heard these words3 ',madame ,curie wishes to speak to you4' ,what extraordinary event--what tragedy1 perhaps1 might this not mean8 ,and suddenly1 over the wire came the sound of the voice which ,i had heard only once before1 but which had stayed in my memory--the same voice which had once pronounced the words1 ',when we consider the progress made by the theories of radio-activity since the beginning of the ,nineteenth ,century----' ',i wanted to tell you that ,i am going to ,america1' she said4 ',it was very hard for me to decide to go1 because ,america is so far and so big4 ,if some one did not come for me1 ,i should probably never have made the trip4 ,i should have been too frightened4 ,but to this fear is added a great joy4 ,i have devoted my life to the science of radio-activity and ,i know all we owe to ,america in the field of science4 ,i am told you are among those who strongly favor this distant trip1 so ,i wanted to tell you ,i have decided to go1 but please don't let any one know about it4' ,this great woman--the greatest woman in ,france--was speaking haltingly1 tremblingly1 almost like a little girl4 ,she1 who handles daily a particle of radium more dangerous than lightning1 was afraid when confronted by the necessity of appearing before the public4 ,a little later1 when ,madame ,curie and ,i had embarked for ,america1 where she was to receive her radium and other experimental material1 ,i asked her if1 the day ,i had first given her the promise1 she had believed that ,american women would rally to her aid4 ,no1 she confessed honestly1 but ,i knew you were sincere4 ,about the time of her marriage1 one of her relatives gave ,madame ,curie a gift of money to be used for a trousseau4 ,it was not a great sum1 but important to the poor student in ,paris4 ,to understand the significance of the use to which she put this fund1 it is necessary to remember that ,marie ,sklodowska was young1 and possessed physical beauty and charm4 ,she was not without appreciation of the beautiful1 and she could not possibly have been utterly unconscious of her own appearance4 ,she had a young girl's natural interest in pretty clothes4 ,she considered the purchase of a wedding gown and other personal belongings1 and then1 with her characteristic exactness1 measured her needs and the future4 ,she was married in a simple dress she had brought from ,poland1 and her trousseau fund was spent on two bicycles1 so that she and ,pierre ,curie might enjoy the beautiful country of ,france4 ,that was their honeymoon4 ,one dream that ,madame ,curie held1 and still holds unrealized1 is the hope of a quiet little home of her own with a garden and hedge1 and flowers and birds4 ,during her ,american travels1 she would frequently glance through the window as the train passed through a small town1 and1 spying some modest little house with a garden1 would say1 ,i have always wanted such a little home4 ,but owning a house was secondary in the life of both ,pierre and ,marie ,curie4 ,they simply made a home wherever they lived1 for such money as might have gone for the purchase of her little dream house was always needed in the laboratory4 ,she told me one day1 with deep feeling1 that one of the regrets of her life was that ,pierre ,curie had died without ever having had a permanent laboratory4 ,she had1 as ,i have said1 refused opportunities to come to the ,united ,states because she could not endure separation from her children4 ,she was1 ,i think1 finally persuaded to face the long trip and the terrifying publicity attending it1 partly because of her gratitude for the support given her scientific work1 but principally because it offered a splendid opportunity for travel to her daughters4 ,there is in ,madame ,curie none of the legendary coldness and thoughtlessness attributed to the scientist4 ,during the war1 when she ran her own radiological truck and lived on the march from hospital to hospital in the zone of operations1 she washed and dried and pressed her own clothes4 ,once during our ,american travels1 we stayed in a home where there were several other house guests besides our party of five4 ,i entered ,madame ,curie's room and found her washing her underclothes4 ,it is nothing at all1 she said1 when ,i protested4 ,i know perfectly well how to do it1 and with all of these extra guests in the house1 the servants have enough to do4 ,on the night before the reception at the ,white ,house1 at which ,president ,harding was to present the gramme of radium to ,madame ,curie1 the ,deed was brought to ,madame ,curie4 ,it was a beautifully engraved scroll1 prepared in the office of ,coudert ,brothers1 vesting all rights to a gramme of radium1 the gift of ,american women1 in ,madame ,curie4 ,she read the paper carefully1 and then1 after a few moments of thought1 said3 ,it is very fine and generous1 but it must not be left this way4 ,this gramme of radium represents a great deal of money1 but more than that1 it represents the women of this country4 ,it is not for me2 it is for science4 ,i am not well2 ,i may die any day4 ,my daughter ,eve is not of legal age1 and if ,i should die it would mean that this radium would go to my estate and would be divided between my daughters4 ,it is not for that purpose4 ,this radium must be consecrated for all time to the use of science4 ,will you have your lawyer draw a paper which will make this very clear8 ,i said that it would be done in a few days4 ,it must be done to-night1 she said4 ,to-morrow ,i receive the radium1 and ,i might die tomorrow4 ,too much is at stake4 ,and so1 late as it was on that hot ,may evening1 after some difficulty1 we secured the services of a lawyer1 who prepared the paper from a draft ,madame ,curie herself had written4 ,she signed it before starting for ,washington4 ,this document read3 ,in the event of my death ,i give to the ,institut du ,radium1 of ,paris1 for exclusive use in the ,laboratoire ,curie1 the gramme of radium which was given to me by the ,executive ,committee of ,women of the ,marie ,curie ,radium ,fund1 pursuant to an agreement dated the #aith day of ,may1 #aiba4 ,this act was consistent with the whole life of the discoverer of radium2 with the answer she had made to my question a year before3 ,radium is not to enrich any one4 ,it is an element2 it is for all people4 ,during her ,american travels1 ,i repeatedly requested ,madame ,curie to write the story of her life4 ,i urged its importance to history and its influence among students preparing to consecrate their lives to science4 ,finally she consented4 ,but it will not be much of a book1 she said4 ,it is such an uneventful1 simple little story4 ,i was born in ,warsaw of a family of teachers4 ,i married ,pierre ,curie and had two children4 ,i have done my work in ,france4 ,a simple statement1 but fraught with what meaning6 ,when most of us shall have been forgotten1 when even the ,great ,world ,war shall have dwindled to a few pages in the history books1 when ,governments shall have fallen and risen and fallen again1 the work of ,marie ,curie will be remembered4 ,of her work and her husband's1 volumes--veritable libraries--have been written since that spring morning in #ahih1 when after an all night vigil in a shack on the outskirts of ,paris1 she came forth with the great gift of radium to mankind4 ,scientists will go on adding to the bibliography of the marvelous element4 ,but of ,marie ,curie herself1 the woman1 it is unlikely that the world will ever read more than the brief notes which compose this small book4 ,it is her conviction1 her philosophy1 that ,in science we should be interested in things1 not persons4 ,,chapter ,i ,,the ,,curie ,,family4 ,,infancy ,,and ,,first ,,studies ,,of ,,pierre ,,curie ,pierre ,curie's parents1 who were educated and intelligent1 formed a part of the petite bourgeoisie of small means4 ,they did not frequent fashionable society1 but confined themselves entirely to the companionship of their relatives and a few intimate friends4 ,eugne ,curie1 ,pierre's father1 was a physician and the son of a physician4 ,he knew very few kinsmen of his name1 and very little about the ,curie family1 which was of ,alsatian 7,eugne ,curie was born at ,mulhouse in #ahbg7 and ,protestant origin4 ,even though his father was established in ,london1 ,eugne had been brought up in ,paris1 where he pursued his studies in the natural sciences and medicine1 and worked as preparator under ,gratiollet in the laboratories of the ,museum4 ,doctor ,eugne ,curie's remarkable personality impressed all who approached him4 ,he was a tall man1 who in youth must have been blonde1 with beautiful blue eyes of a clearness and brilliancy that were striking even in an advanced old age4 ,these eyes1 which had retained a child-like expression1 reflected goodness and intelligence4 ,he had indeed unusual intellectual capacities1 a very live aptitude for the natural sciences1 and the temperament of a scholar4 ,although he wished to consecrate his life to scientific work1 family responsibilities following his marriage and the birth of two sons forced him to renounce this desire4 ,the necessities of life obliged him to practice his medical profession4 ,he continued1 however1 such experimental research as his means permitted1 in particular undertaking an investigation upon inoculation for tuberculosis at a time when the bacterial nature of this malady was not yet established4 ,his scientific avocations developed in him the habit of making excursions in search of the plants and animals necessary to his experiments1 and this habit1 as well as his love of ,nature1 gave him a marked preference for country life4 ,until the end of his life he conserved his love for science1 and1 without doubt1 also1 his regret at not having been able to devote himself exclusively to it4 ,his medical career remained always a modest one1 but it revealed remarkable qualities of devotion and disinterestedness4 ,at the time of the ,revolution of #ahdh1 when he was still a student1 the ,government of the ,republic conferred on him a medal1 for his honorable and courageous conduct in serving the wounded4 ,he himself had been struck1 on ,february #bdth1 by a ball which shattered a part of his jaw4 ,a little later1 during a cholera epidemic1 he installed himself1 in order that he might look after the sick1 in a quarter of ,paris deserted by physicians4 ,during the ,commune he established a hospital in his apartment 7rue de la ,visitation7 near which there was a barricade1 and there he cared for the wounded4 ,through this act of civism and because of his advanced convictions he lost a part of his bourgeois patronage4 ,at this time he accepted the position of medical inspector of the organization for the protection of young children4 ,the duties of this post permitted him to live in the suburbs of ,paris where health conditions for himself and his family were much better than those of the city4 ,doctor ,curie had very pronounced political convictions4 ,temperamentally an idealist1 he had embraced with ardor that republican doctrine which inspired the revolutionaries of #ahdh4 ,he was united in friendship with ,henri ,brisson and the men of his group4 ,like them1 a free thinker and an anticlerical1 he did not have his sons baptized1 nor did he have them practice any form of religion4 ,pierre's mother1 ,claire ,depouilly1 was the daughter of a prominent manufacturer of ,puteaux1 near ,paris4 ,her father and brothers distinguished themselves through their numerous inventions connected with the making of dyes and special tissues4 ,the family1 which was of ,savoy1 was caught in the business catastrophe caused by the ,revolution of #ahdh1 and ruined4 ,and these reverses of fortune1 added to those which ,doctor ,curie had experienced during his career1 meant that he and his family lived always in comparatively straightened circumstances1 with the difficulties of existence often renewed4 ,even though raised for a life of ease1 ,pierre's mother accepted with tranquil courage the precarious conditions which life brought her1 and gave proof of an extreme devotion as she made life easier for her husband and children by her activity and her good will4 ,if the circumstances in which ,jacques and ,pierre grew up were modest and not free from cares1 nevertheless there reigned in the family an atmosphere of gentleness and affection4 ,in speaking to me for the first time of his parents1 ,pierre ,curie said that they were exquisite4 ,they were1 in truth1 that4 ,the father's spirit was a little authoritative--always awake and active4 ,and he possessed a rare unselfishness4 ,he neither wished nor knew how to profit by personal relations to ameliorate his condition4 ,he loved his wife and sons tenderly1 and was ever ready to aid all who needed him4 ,the mother was slight1 vivid in character1 and1 even though her health had suffered through the birth of her sons1 was always gay and active in the simple home that she so well knew how to make attractive and hospitable4 ,when ,i first knew them they lived at ,sceaux1 rue des ,sablons 7to-day rue ,pierre ,curie7 in a little house of ancient construction half concealed amidst the verdure of a pretty garden4 ,their life was peaceful4 ,doctor ,curie went where his duties called him1 either in ,sceaux or in neighboring localities4 ,beyond this he occupied himself with his garden or his reading4 ,near relatives and neighbors came to visit on ,sundays1 when bowling and chess were the favorite amusements4 ,from time to time ,henri ,brisson sought out his old companion in his tranquil retreat4 ,great calm and serenity enveloped the garden1 the dwelling1 and its inhabitants4 ,pierre ,curie was born the #aeth of ,may1 #ahei1 in a house facing the ,jardin des ,plantes1 rue ,cuvier1 where his parents lived at the time when his father was working in the ,museum laboratories4 ,he was the second son of ,doctor ,curie and three and a half years younger than his brother ,jacques4 ,in after life he retained few particularly characteristic memories of his childhood in ,paris2 yet he did tell me how vividly present in his mind were the days of the ,commune1 the battle on the barricade so near the house where he then lived1 the hospital established by his father1 and the expeditions1 on which his brother accompanied him1 in search of the wounded4 ,it was in #ahhc that ,pierre moved with his parents from the capital to the suburbs of ,paris1 living first1 from #ahhc to #ahib1 at ,fontenay-aux-,roses1 then at ,sceaux from #ahib to #ahie1 the year of our marriage4 ,pierre passed his childhood entirely within the family circle2 he never went to the elementary school nor to the lyce4 ,his earliest instruction was given him first by his mother and was then continued by his father and his elder brother1 who himself had never followed in any complete way the course of the lyce4 ,pierre's intellectual capacities were not those which would permit the rapid assimilation of a prescribed course of studies4 ,his dreamer's spirit would not submit itself to the ordering of the intellectual effort imposed by the school4 ,the difficulty he experienced in following such a program was usually attributed to a certain slowness of mind4 ,he himself believed that he had this slow mind and often said so4 ,i think1 however1 that this belief was not entirely justified4 ,it seems to me1 rather1 that already from his early youth it was necessary for him to concentrate his thought with great intensity upon a certain definite object1 in order to obtain a precise result1 and that it was impossible for him to interrupt or to modify the course of his reflections to suit exterior circumstances4 ,it is clear that a mind of this kind can hold within itself great future possibilities4 ,but it is no less clear that no system of education has been especially provided by the public school for persons of this intellectual category1 which nevertheless includes more representatives than one would believe at first sight4 ,very fortunately for ,pierre1 who could not1 as we can see1 become a brilliant pupil in a lyce1 his parents had a sufficiently keen intelligence to understand his difficulty1 and they refrained from demanding of their son an effort which would have been prejudicial to his development4 ,if1 then1 ,pierre's earliest instruction was irregular and incomplete1 it had the advantage of not so weighing on his intelligence as to deform it by dogmas1 prejudices or preconceived ideas4 ,and he was always grateful to his parents for this very liberal attitude4 ,he grew up in all freedom1 developing his taste for natural science through his excursions into the country1 where he collected plants and animals for his father4 ,these excursions1 which he made either alone or with one of the family1 helped to awake in him a great love of ,nature1 a passion which endured to the end of his life4 ,intimate contact with ,nature1 which1 because of the artificial conditions of city life and of traditional education1 few children can know1 had a decisive influence on ,pierre's development4 ,guided by his father1 he learned to observe facts and to interpret them correctly4 ,he became familiar with the animals and plants of the environs of ,paris4 ,he knew which ones could be found at each season of the year in the forests and fields1 the streams and ponds4 ,the ponds in particular had for him an ever new attraction with their characteristic vegetation and their population of frogs1 tritons1 salamanders1 dragonflies1 and other denizens of air and water4 ,no efforts to obtain the objects of his interests seemed too great for him4 ,he never hesitated to take any animal in his hands in order to examine it more closely4 ,later1 after our marriage1 in our walks together1 if ,i made some objection to letting him put a frog into my hands1 he would exclaim3 ,but no1 see how pretty it is6 ,he loved always1 too1 to bring back bouquets of wild flowers from his walks4 ,thus his knowledge of natural history progressed rapidly4 ,at the same time1 also1 he was mastering the elements of mathematics4 ,his classical studies1 on the contrary1 had been much neglected1 and it was principally through general reading that he acquired a knowledge of literature and history4 ,his father1 who was widely cultured1 possessed a library containing many ,french and foreign works4 ,having himself a very pronounced taste for reading1 he was able to communicate it to his son4 ,when he was about fourteen years old1 a very happy event occurred in ,pierre's education4 ,he was put under an excellent professor1 ,a4 ,bazille1 who taught him elementary and advanced mathematics4 ,this master was able to appreciate his young pupil1 became much attached to him1 and directed his work with the greatest solicitude4 ,he even helped him to advance in his study of ,latin1 in which he was very much behind4 ,at the same time ,pierre and ,albert ,bazille1 his professor's son1 became friends4 ,this teaching had1 ,i am sure1 a great influence on the mind of ,pierre1 aiding him to develop and to sound the depth of his faculties and to realize his capacities for science4 ,he had a remarkable aptitude for mathematics1 which expressed itself chiefly by a characteristic geometric spirit and a great power of spatial vision4 ,he1 therefore1 progressed rapidly and joyfully in his studies under ,m4 ,bazille1 for whom he always felt an unalterable gratitude4 ,he once told me something which proved that even at this time he was not content solely to follow a fixed program of studies1 but that he had already begun to launch out into personal investigation4 ,strongly attracted by the theory of determinants1 which he had just mastered1 he undertook to realize an analogous conception1 but in three dimensions1 and endeavored to discover the properties and uses of these cubical determinants4 ,needless to say that at his age1 and with the knowledge then at his disposal1 such an enterprise was beyond his powers4 ,the attempt1 however1 was none the less indicative of his awakening inventive spirit4 ,several years later1 when preoccupied with reflections upon symmetry1 he asked himself the question3 ,could not one find a general method for the solution of any equation whatever8 ,everything is a question of symmetry4 ,he did not then know of ,galois' theory of groups which had made it possible to attack this problem4 ,but he was happy later to learn its results in the geometric applications to the case of equations of the #eth degree4 ,thanks to his rapid progress in mathematics and physics1 ,pierre ,curie was made a bachelor of science at the age of sixteen years4 ,with this he passed his most difficult stage of formal education4 ,the only thing with which he had to concern himself in the future was the acquisition of knowledge through his personal and independent effort in a field of science freely chosen4 ,,chapter ,,ii ,,dreams ,,of ,,youth4 ,,first ,,scientific ,,work4 ,,discovery ,,of ,,piezo-,,electricity ,pierre ,curie was still very young when he began his higher studies in preparation for the licentiate in physics4 ,he followed the lectures and laboratory work at the ,sorbonne and had1 besides1 access to the laboratory of ,professor ,leroux in the ,school of ,pharmacy1 where he assisted in the preparation of the physics courses4 ,at the same time he became further acquainted with laboratory methods by working with his brother ,jacques1 who was then preparator of chemistry courses under ,riche and ,jungfleisch4 ,pierre received his licentiate in physical sciences at the age of eighteen4 ,during his studies he had attracted the attention of ,desains1 director of the ,university laboratory1 and of ,mouton1 assistant director of the same laboratory4 ,thanks to their appreciation he was appointed1 when only nineteen years old1 preparator for ,desains and placed in charge of the students' laboratory work in physics4 ,he held this position five years1 and it was during this time that he began his experimental research4 ,it is to be regretted that because of his financial situation ,pierre was obliged1 at this early age of nineteen1 to accept the post of preparator instead of being able to give his whole time for two or three years longer to his ,university studies4 ,with his time thus absorbed by his professional duties and his investigations he had to give up following the lectures in higher mathematics1 and he therefore passed no further examinations4 ,in compensation1 however1 he was released from military service in conformity with the privileges at that time accorded young men who undertook to serve as teachers in the public-school system4 ,he was by this time a tall and slender young man with chestnut-colored hair and a shy and reserved expression4 ,at the same time his youthful face mirrored a profound inner life4 ,one has such an impression of him as he appears in a good group photograph of ,doctor ,curie's family4 ,his head is resting on his hand in a pose of abstraction and reverie1 and one cannot but be struck by the expression of the large1 limpid eyes that seem to be following some inner vision4 ,beside him the brown-haired brother offers a striking contrast1 his vivacious eyes and whole appearance suggesting decision4 ,the two brothers loved each other tenderly and lived as good comrades1 being accustomed to work together in the laboratory and walk together in their free hours4 ,they also kept up affectionate relations with a few of their childhood friends3 ,louis ,depouilly1 their cousin1 who became a physician2 ,louis ,vauthier1 also later a physician2 and ,albert ,bazille1 who became an engineer in the post and telegraph service4 ,pierre used to tell me of the vivid memories he had of the vacations passed at ,draveil on the ,seine1 where1 with his brother ,jacques1 he took long walks beside the river1 agreeably interrupted by swimming and diving in the stream4 ,both brothers were excellent swimmers4 ,sometimes they tramped for entire days4 ,they had1 at an early age1 acquired the habit of visiting the suburbs of ,paris on foot4 ,at times also ,pierre made solitary excursions which well suited his meditative spirit4 ,on these occasions he lost all sense of time1 and went to the extreme limit of his physical forces4 ,absorbed in delightful contemplation of the things about him1 he was not conscious of material difficulties4 ,on the pages of a diary written in #ahgi1a he thus expressed the salutary influence of the country upon him3 ,oh1 what a good time ,i have passed there in that gracious solitude1 so far from the thousand little worrying things that torment me in ,paris4 ,no1 ,i do not regret my nights passed in the woods1 and my solitary days4 ,if ,i had the time ,i would let myself recount all my musings4 ,i would also describe my delicious valley1 filled with the perfume of aromatic plants1 the beautiful mass of foliage1 so fresh and so humid1 that hung over the ,bivre1 the fairy palace with its colonnades of hops1 the stony hills1 red with heather1 where it was so good to be4 ,oh1 ,i shall remember always with gratitude the forest of the ,minire2 of all the woods ,i have seen1 it is this one that ,i have loved most and where ,i have been happiest4 ,often in the evening ,i would start out and ascend again this valley1 and ,i would return with twenty ideas in my head4 ,thus1 for ,pierre ,curie1 the sensation of well-being he experienced in the country was derived from the opportunity for tranquil reflection4 ,daily life in ,paris with its numerous interruptions did not permit of undisturbed concentration1 and this was to him a cause of inquietude and suffering4 ,he felt himself destined for scientific research2 for him the necessity was imperative of comprehending the phenomena of ,nature in order to form a satisfactory theory to explain them4 ,but when trying to fix his mind on some problem he had frequently to turn aside because of the multiplicity of futile things that disturbed his reflections and plunged him into discouragement4 ,under the heading1 ,a day like too many others1 he enumerated in his diary a list of the puerile happenings that had completely filled one of his days1 leaving no time for useful work4 ,he then concluded3 ,there is my day1 and ,i have accomplished nothing4 ,why8 ,further on he returns to the same theme under a title borrowed from ,victor ,hugo's ,le ,roi ,s',amuse1 ,to deafen with little bells the spirit that would think4 ,in order that1 weak one that ,i am1 ,i shall not let my head turn with all the winds1 yielding to the least breath that touches it1 it is necessary that all should be immobile about me1 or that1 like a spinning top1 movement alone should render me insensible to external objects4 ,when1 in the process of turning slowly upon myself1 ,i try to gain momentum1 a nothing1 a word1 a story1 a paper1 a visit stops me and is able to put off or retard forever the moment when1 granted a sufficient swiftness ,i might have1 in spite of my surroundings1 concentrated on my own intention4444 ,we must eat1 drink1 sleep1 be idle1 love1 touch the sweetest things of life and yet not succumb to them4 ,it is necessary that1 in doing all this1 the higher thoughts to which one is dedicated remain dominant and continue their unmoved course in our poor heads4 ,it is necessary to make a dream of life1 and to make of a dream a reality4 ,this acute analysis1 sufficiently surprising in a young man of twenty years1 suggests in an admirable manner the conditions necessary to the highest manifestations of the intellect4 ,it carries a lesson which1 if it were sufficiently understood1 would facilitate the way of all contemplative spirits capable of opening new paths for humanity4 ,the unity of thought toward which ,pierre ,curie strove was troubled not only by professional and social obligations but also by his tastes1 which urged him towards a broad literary and artistic culture4 ,like his father1 he loved reading1 and did not fear to undertake arduous literary tasks4 ,to some criticism made in this connection1 he responded readily3 ,i do not dislike tedious books4 ,this meant that he was fascinated by the search after truth which is sometimes associated with writing devoid of charm4 ,he also loved painting and music1 and went gladly to look at pictures or to attend a concert4 ,a few fragments of poetry in his handwriting were left among his papers4 ,but all these preoccupations were subordinated in his mind to what he considered his true task1 and when his scientific imagination was not in full activity1 he felt himself1 in a sense1 an incomplete being4 ,he expressed this inquietude with an emotion born of his suffering during momentary periods of depression4 ,what shall ,i become8 he wrote4 ,very rarely have ,i command of all myself2 ordinarily a part of me sleeps4 ,my poor spirit1 are you then so weak that you cannot control my body8 ,oh1 my thoughts1 you count indeed for very little6 ,i should have the greatest confidence in the power of my imagination to pull me out of the rut1 but ,i greatly fear that my imagination is dead4 ,but despite hesitations1 doubts1 and lost moments1 the young man was little by little striking out his path and strengthening his will4 ,he was resolutely carrying on fruitful investigations at an age when many men who were to become savants were as yet only pupils4 ,his first work1 done in collaboration with ,desains1 concerned the determination of the lengths of heat waves with the aid of a thermoelectric element and a metallic wire grating1 a process1 then entirely new1 which has since often been employed in the study of this question4 ,following this he undertook an investigation on crystals in collaboration with his brother1 who had passed his licentiate and was preparator for ,friedel in the laboratory of mineralogy at the ,sorbonne4 ,their experiments led the two young physicists to a great success3 the discovery of the hitherto unknown phenomena of piezo-electricity1 which consists of an electric polarization produced by the compression or the expansion of crystals in the direction of the axis of symmetry4 ,this was by no means a chance discovery4 ,it was the result of much reflection on the symmetry of crystalline matter1 which enabled the brothers to foresee the possibilities of such polarization4 ,the first part of the investigation was made in ,friedel's laboratory4 ,with an experimental skill rare at their age1 the young men succeeded in making a complete study of the new phenomenon1 established the conditions of symmetry necessary to its production in crystals1 and stated its remarkably simple quantitative laws1 as well as its absolute magnitude for certain crystals4 ,several well-known scientists of other nations 7,roentgen1 ,kundt1 ,voigt1 ,riecke7 have made further investigations along this new road opened by ,jacques and ,pierre ,curie4 ,the second part of the work1 and much more difficult to realize experimentally1 concerned the compression resulting in piezo-electric crystals when they are exposed to the action of an electric field4 ,this phenomenon1 foreseen by ,lippmann1 was demonstrated by the ,curie brothers4 ,the difficulty of the experiment lay in the minuteness of the deformations that had to be observed4 ,fortunately ,desains and ,mouton placed a small room adjoining the physics laboratory at the disposal of the brothers so that they might proceed successfully with their delicate operations4 ,from these researches1 as much theoretical as experimental1 they immediately deduced a practical application1 in the form of a new apparatus1 a piezo-electric quartz electrometer1 which measures in absolute terms small quantities of electricity1 as well as electric currents of low intensity4 ,this apparatus has since then rendered great service in experiments in radioactivity4#b ,during the course of their experiments on piezo-electricity the ,curies were obliged to employ electrometric apparatus1 and1 not being able to use the quadrant electrometer known at that time1 they developed a new form of that instrument1 better adapted to their necessities4 ,this became known in ,france as the ,curie electrometer4 ,thus these years of collaboration between the two brothers1 always intimately united1 proved both happy and fruitful4 ,their devotion and their common interest in science were to them both a stimulant and a support4 ,during their work the vivacity and energy of ,jacques were of precious aid to ,pierre1 always more easily absorbed by his thoughts4 ,however1 this beautiful and close collaboration lasted only a few years4 ,in #ahhc1 ,pierre and ,jacques were obliged to separate2 ,jacques left for the ,university of ,montpellier as ,head ,lecturer in ,mineralogy 7,matre de ,conferences74 ,pierre was made ,director of ,laboratory ,work in the ,school of ,industrial ,physics and ,chemistry founded by the city of ,paris at the suggestion of ,friedel and of ,schtzenberger1 who became its first director4 ,their remarkable researches with crystals won for the brothers in #ahie--very late1 it is true--the ,plant prize4 ,footnote #a3 ,pierre ,curie did not leave a veritable diary but only a few pages as chance permitted1 covering but a short period of his life4 ,footnote #b3 ,the piezo-electric property of quartz has recently had an important application2 it has been utilized by ,p4 ,langevin in the production of elastic waves of high frequency 7beyond sound7 sent out in water with the aim of detecting submarine obstacles4 ,this same method can serve in a more general manner to explore ocean depths4 ,we see1 here1 once again1 how pure speculation can lead to discoveries that will be useful later in unforeseen directions4 ,,chapter ,,iii ,,life ,,as ,,the ,,director ,,of ,,laboratory ,,work ,,in ,,the ,,school ,,of ,,physics ,,and ,,chemistry4 ,,generalization ,,of ,,the ,,principle ,,of ,,symmetry4 ,,investigations ,,of ,,magnetism ,it was in the ,school of ,physics1 in the old buildings of the ,collge ,rollin1 that ,pierre ,curie was destined to work1 first as ,director of ,laboratory ,work1 then as ,professor1 for twenty-two years1 a period covering practically the whole of his scientific life4 ,his memory seemed to cling to these old buildings1 now destroyed1 in which he had passed all his days1 returning only in the evening to his parents in the country4 ,he counted himself fortunate since he enjoyed the favor of the ,founder-,director ,schtzenberger1 and the esteem and good will of his students1 many of whom became his disciples and friends4 ,in alluding to this experience1 at the close of an address delivered at the ,sorbonne near the end of his life1 he said3 ,i desire to recall here that we have made all our investigations in the ,school of ,physics and ,chemistry of the city of ,paris4 ,in all creative scientific work the influence of the surroundings in which one works is of great importance1 and a part of the result is due to that influence4 ,for more than twenty years ,i have worked in the ,school of ,physics and ,chemistry4 ,schtzenberger1 the first director of the ,school1 was an eminent scientist4 ,i remember with gratitude that he procured for me opportunities for my own investigations when ,i was yet but an assistant4 ,later1 he permitted ,madame ,curie to work beside me1 an authorization which was at that time far from an ordinary innovation4 ,schtzenberger allowed us all great liberty2 his direction made itself felt chiefly through his inspiring love of science4 ,the professors of the ,school of ,physics and ,chemistry1 and the students who have gone from it1 have created a kindly and stimulating atmosphere that has been extremely helpful to me4 ,it is among the old students of the school that we have found our collaborators and our friends4 ,i am happy to be able1 here1 to thank them all4 ,the newly appointed director of the laboratory was1 when he first assumed his duties1 scarcely older than his students1 who loved him because of his extreme simplicity of manner1 which was much more that of a comrade than of a master4 ,some of these students recall with emotion their work carried on with him and his discussion at the blackboard1 where he readily allowed himself to be led to debate scientific matters to their great profit both in information and in kindled enthusiasm4 ,at a dinner given in #aijc by the ,association of ,former ,students of the ,school1 which he attended1 he laughingly recalled an incident of this period4 ,one day after lingering late with several students in the laboratory1 he found the door locked1 and they all had to climb down from the first floor single file1 along a pipe that ran near one of the windows4 ,because of his reserve and shyness he did not make acquaintances easily1 but those whose work brought them near him loved him because of his kindliness4 ,this was true of his subordinates during his entire life4 ,in the school his laboratory helper1 whom he had aided under trying circumstances1 thought of him with the greatest gratitude1 in fact1 with veritable adoration4 ,although separated from his brother1 he remained bound to him by their former bond of love and confidence4 ,during vacations1 ,jacques ,curie would come to him that they might renew again that valuable collaboration to which both willingly sacrificed their periods of liberty4 ,at times it was ,pierre who joined ,jacques1 who was engaged in making a geological chart of the ,auvergne country1 and there they covered together the daily distances necessary to the tracing of such a map4 ,here are a few memories of these long walks1 extracts from a letter written to me shortly before our marriage3 ,i have been very happy to pass a little time with my brother4 ,we have been far from all immediate care1 and so isolated by our manner of living that we have not even been able to receive a letter1 never knowing one night where we would sleep the next4 ,at times it seemed to me that we had gone back to the days when we lived entirely together4 ,then we always arrived at the same opinions about all things1 with the result that it was no longer necessary for us to speak in order to understand each other4 ,this was all the more astonishing because we differed so entirely in character4 ,from the point of view of scientific investigation1 one must recognize that the nomination of ,pierre ,curie to the ,school of ,physics and ,chemistry retarded from the very first his experimental research4 ,indeed1 at the time of his appointment nothing yet existed in that establishment2 everything had to be created4 ,even the walls and the partitions were hardly yet in place4 ,he had1 therefore1 to organize completely the laboratory and its work1 and he acquitted himself of this task in a remarkable manner1 injecting into it the spirit of precision and originality so characteristic of him4 ,the direction of the laboratory work of the large number of students 7thirty by promotion7 was alone a strain on a young man1 assisted as he was only by one laboratory helper4 ,the first years were1 therefore1 hard years of assiduous work1 of benefit chiefly to the students trained and developed by the young laboratory director4 ,he himself profited by this enforced interruption of his experimental research by trying to complete his scientific studies and1 in particular1 his knowledge of mathematics4 ,at the same time he became engrossed in considerations of a theoretical nature on the relations between crystallography and physics4 ,in #ahhd he published a memoir on questions of the order and repetition that are at the base of the study of the symmetry of crystals4 ,this was followed in the same year by a more general treatment of the same subject4 ,another article on symmetry and its repetitions appeared in #ahhe4 ,in that year he published1 too1 a very important theoretical work#c on the formation of crystals1 and the capillary constants of the different faces4 ,this rapid succession of investigations shows how completely engrossed ,pierre ,curie was in the subject of the physics of crystals4 ,both his theoretical and his experimental research in this domain grouped itself around a very general principle1 the principle of symmetry1 that he had arrived at step by step1 and which he only definitely enunciated in memoirs published between the years #ahic and #ahie4 ,the following is the form1 already classic1 in which he made his announcement3 ,when certain causes produce certain effects1 the elements of symmetry in the causes ought to reappear in the effects produced4 ,when certain effects reveal a certain dissymmetry1 this dissymmetry should be apparent in the causes which have given them birth4 ,the converse of these two statements does not hold1 at least practically2 that is to say1 the effects produced can be more symmetrical than their causes4 ,the capital importance of this statement1 perfect in its simplicity1 lies in the fact that the elements of symmetry which it introduces are related to all the phenomena of physics without exception4 ,guided by an exhaustive study of the groups of symmetry which might exist in nature1 ,pierre ,curie showed how one should use this revelation in character at once geometric and physical1 in order to foresee whether a particular phenomenon can reproduce itself1 or whether its reproduction is impossible under the given conditions4 ,at the beginning of a certain memoir1 he insists in these terms3 ,i think it is necessary to introduce into physics the ideas of symmetry familiar to crystallographers4 ,his work in this field is fundamental1 and even though he was led away from it later by other investigations1 he always retained a passionate interest in the physics of crystals1 as well as in projects of further research in this domain4 ,the principle of symmetry to which ,pierre ,curie had so eagerly devoted himself is one of the small number of great principles which dominate the study of the phenomena of physics1 and which1 having their root in ideas derived by experiment1 yet little by little detach themselves and assume a form more and more general and more and more perfect4 ,it is in this way that the idea of the equivalence of heat and of work1 added to the earlier notion of the equivalence of kinetic and potential energies1 brought about the establishment of the principle of the conservation of energy whose application is entirely general4 ,in the same way the law of the conservation of mass grew out of the experiments of ,lavoisier1 which belong to the foundations of chemistry4 ,recently an admirable synthesis has made it possible for us to attain a still higher degree of generalization through the union of these two principles1 for it has been proved that the mass of a body is proportional to its internal energy4 ,the study of electrical phenomena led ,lippmann to announce the general law of the conservation of electricity4 ,the principle of ,carnot1 born of considerations on the functioning of thermal machines1 has acquired also so general a significance1 that it made possible the foreseeing of the most probable character of spontaneous evolution for all material systems4 ,the principle of symmetry furnishes an example of an analogous evolution4 ,to begin with1 observation of ,nature was able to suggest the idea of symmetry2 though such observations reveal only imperfectly any regular dispositions in the aspects of animals and plants4 ,the regularity becomes very much more perfect in the case of crystallized minerals4 ,we may consider that ,nature furnishes us the idea of a plane of symmetry and of an axis of symmetry4 ,an object possesses a plane of symmetry1 or a plane of reflection1 if this plane divides the object into two parts1 of which each one may be thought of as the image of the other reflected in the plane as in a mirror4 ,it is this1 approximately1 that occurs in the external appearance of man and of numerous animals4 ,an object possesses an axis of symmetry of the order n1 if it preserves the same appearance after a rotation on this axis of the nth part of a revolution4 ,thus a regular flower of four petals has an axis of symmetry of the order four1 or a quarternary axis4 ,crystals like those of rock salt or of alum possess many planes of symmetry and many axes of symmetry of different orders4 ,geometry teaches us to study the elements of symmetry of a limited figure such1 for instance1 as a polyhedron2 and to discover the relations between its parts which permit us to reunite different symmetries in groups4 ,the knowledge of these groups is of the greatest usefulness in establishing a rational classification of crystal forms in a small number of systems each of which is derived from a simple geometric form4 ,thus the regular octahedron belongs to the same system as the cube1 for in the case of each the group formed by the axes and the planes of symmetry is the same4 ,in the study of the physical properties of crystalline matter it is necessary to take account of the symmetry of such matter4 ,this is1 in general1 anisotropic2 that is to say1 it has not the same properties in all directions4 ,on the other hand1 media such as glass or water are isotropic1 having equivalent properties in all directions4 ,it was the study of optics which first showed that the propagation of light in a crystal is dependent upon the elements of symmetry in that crystal4 ,the same thing is true for the conduction of heat or electricity1 for magnetization1 for polarization1 etc4 ,it was in reflecting upon the relations between cause and effect that govern these phenomena that ,pierre ,curie was led to complete and extend the idea of symmetry1 by considering it as a condition of space characteristic of the medium in which a given phenomenon occurs4 ,to define this condition it is necessary to consider not only the constitution of the medium but also its condition of movement and the physical agents to which it is subordinated4 ,thus a right circular cylinder possesses a plane of symmetry perpendicular to its axis in its position1 and an infinity of planes of symmetry pass through its axis4 ,if the same cylinder is in rotation on its axis1 the first plane of symmetry persists1 but all the others are suppressed4 ,furthermore1 if an electric current traverses the cylinder lengthwise1 no plane of symmetry remains4 ,in every phenomenon the elements of symmetry compatible with its existence may be determined4 ,certain elements can coexist with certain phenomena1 but they are not necessary to them4 ,that which is necessary is that certain ones among these elements shall not exist4 ,it is dissymmetry that creates the phenomenon4 ,when several phenomena are superposed in the same system1 the dissymmetries are added together4 ,works of ,pierre ,curie1 page #abg4 ,it was from the above considerations that ,pierre ,curie announced the general law whose text1 already cited1 attains the highest degree of generalization4 ,the synthesis thus obtained seems complete1 and all that was further needed was to deduce from it all the developments of which it admits4 ,for this it is convenient to define the particular symmetry of each phenomenon and to introduce a classification which makes clear the principal groups of symmetry4 ,mass1 electric charge1 temperature1 have the same symmetry1 of a type called scalar1 that of the sphere4 ,a current of water and a rectilineal electric current have the symmetry of an arrow1 of the type polar vector4 ,the symmetry of an upright circular cylinder is of the type tensor4 ,all of the physics of crystals can be expressed in a form in which the particular phenomena in question are not specified1 but in which are examined only the geometrical and analytical relations between the types of quantities where certain ones are considered as causes and the other as effects4 ,thus1 the study of electrical polarization by the application of an electric field becomes the examination of the relation between two systems of vectors1 and the writing out of a system of linear equations having #i coefficients4 ,the same system of equations holds for the relation between an electric field and an electric current in crystalline conductors2 or for that between the temperature gradient and the heat current1 except that the meaning of the coefficients must be changed4 ,similarly1 a study of the general relations between a vector and a system of tensors can reveal all the characteristics of piezo-electric phenomena4 ,and all the rich variety of the phenomena of elasticity depends on the relation between two sets of tensors which require1 in principle1 #cf coefficients4 ,the foregoing brief exposition reveals the high philosophic import of these conceptions of symmetry which touch all natural phenomena1 and whose profound significance ,pierre ,curie so clearly set forth4 ,it is interesting in this connection to recall the relation which ,pasteur saw between these same conceptions and the manifestations of life4 ,the universe1 he said1 is a dissymmetric whole4 ,i am led to believe that life1 as it is revealed to us1 must be a function of the dissymmetry of the universe1 or of the consequences that it involves4 ,as his organization of his work in the ,school progressed1 ,pierre ,curie could begin to dream of going forward again with his experimental research4 ,he could do so1 however1 only under most precarious conditions1 for he had not even a laboratory for his personal work1 nor a room of any kind entirely at his disposition4 ,besides1 he possessed no funds to support his investigations4 ,it was only after he had been several years at the ,school that he obtained1 thanks to the influence of ,schtzenberger1 a small annual subvention for his work4 ,up to that time the materials necessary for him were provided1 thanks to the kindness of his superiors1 to the extent possible1 by drawing upon a very limited general fund of the teaching laboratory4 ,as for a place to work in1 he had to content himself with very little4 ,he set up certain of his experiments in the rooms of his pupils when these were not in use4 ,but more frequently he worked in an outside corridor running between a stairway and a laboratory4 ,it was there that he conducted1 in particular1 his long research on magnetism4 ,this abnormal state of affairs was manifestly prejudicial to his work1 but it had1 nevertheless1 the happy result of bringing his students closer to him1 for it allowed them1 at times1 to share in his personal scientific interests4 ,his return to experimental research is marked by a profound study of the direct reading periodic precision balance for least weights4 7#ahhi1 #ahij1 #ahia47 ,in this balance1 the use of small weights is suppressed by the employment of a microscope by means of which one reads a micrometer attached to the extremity of one of the arms of the balance4 ,the reading is made when the oscillation of the balance is arrested1 which can occur very rapidly1 thanks to the use of pneumatic dampeners conveniently constructed4 ,this balance marks a considerable advance over old systems4 ,it has shown itself particularly valuable in laboratories for chemical analysis1 where the rapidity of the weighings is frequently a test of precision4 ,we can say that the introduction of the ,curie balances marks an epoch in the construction of these instruments4 ,the work done in this field was far from empirical2 it comprised a study of the theory of damped movements and the construction of numerous curves established with the aid of some of his students4 ,it was toward #ahia that ,pierre ,curie began a long series of investigations on the magnetic properties of bodies at divers temperatures1 from the normal up to #adjj ,c4 ,these investigations1 covering years1 were presented as a ,doctor's thesis before the ,faculty of ,sciences of the ,university of ,paris in #ahie4 ,in it he stated precisely in the following few words the object and results of his work3 ,from the point of view of their magnetic properties1 bodies may be divided into two groups3 diamagnetic bodies1 bodies only feebly magnetic1 and paramagnetic bodies4#d ,at first sight the two groups seem entirely separate4 ,the principal aim of this research has been to discover if there exist transitions between these two states of matter1 and if it is possible to make a given body pass progressively through them4 ,to determine this ,i have examined the properties of a great number of bodies at temperatures differing as much as possible1 in magnetic fields of varying intensities4 ,my experiments failed to prove any relation between the properties of diamagnetic and those of paramagnetic bodies4 ,and the results support the theories which attribute magnetism and diamagnetism to causes of a different nature4 ,on the contrary1 the properties of ferro-magnetic bodies and of bodies feebly magnetic are intimately united4 ,this experimental work presented many difficulties1 for it necessitated the measuring of very minute forces 7of the order of of a milligramme weight7 within a container where the temperature could attain #djj ,c4 ,as ,pierre ,curie well understood1 the results he obtained are1 from a theoretic point of view1 of fundamental importance4 ,the ,curie law1 according to which the coefficient of magnetization of a body feebly magnetized varies in inverse ratio to the absolute temperature1 is a remarkably simple law4 ,it is quite comparable to the ,gay-,lussac law relating to the variation of the density of a perfect gas with the temperature4 ,in his well known theory of magnetism ,p4 ,langevin1 in #aije1 took into account the ,curie law and arrived again1 theoretically1 at the difference between the origins of diamagnetism and paramagnetism4 ,his work1 as well as the important investigations of ,p4 ,weiss1 demonstrated the accuracy of ,pierre ,curie's conclusions1 as well as the importance of the analogy that he perceived between the intensity of magnetization and the density of a fluid--the paramagnetic state being comparable to a gaseous state1 and the ferro-magnetic state to the state of condensation4 ,in connection with this work1 ,pierre ,curie spent some time in the search for unknown phenomena whose existence did not seem1 a priori1 impossible to him4 ,he sought for bodies strongly diamagnetic1 but found none4 ,he tried to discover1 too1 if there were bodies that acted as conductors of magnetism1 and if magnetism can exist in a free state1 like electricity4 ,here also the result was negative4 ,he never published any of these investigations1 for he had the habit of thus engaging in the pursuit of phenomena1 often with little hope of success1 solely for the love of the unforeseen1 and without ever thinking of publication4 ,because of this entirely disinterested passion for scientific research the presentation of a doctor's thesis which would give an account of these early investigations had never appealed to him4 ,he was already thirty-five years old when he decided to gather together1 in such a thesis1 the results of his beautiful work on magnetism4 ,i have a very vivid memory of how he sustained his thesis before the examiners1 for he had invited me1 because of the friendship that already existed between us1 to be present on the occasion4 ,the jury was composed of ,professors ,bonty1 ,lippmann1 and ,hautefeuille4 ,in the audience were some of his friends1 among them his aged father1 extremely happy in his son's success4 ,i remember the simplicity and the clarity of the exposition1 the esteem indicated by the attitude of the professors1 and the conversation between them and the candidate which reminded one of a meeting of the ,physics ,society4 ,i was greatly impressed2 it seemed to me that the little room that day sheltered the exaltation of human thought4 ,in recalling this period in the life of ,pierre ,curie1 between #ahhc and #ahie1 we can appreciate the great progress the young physicist had made while acting as ,chief of ,laboratory4 ,he had succeeded during this time in organizing an entirely new teaching service2 he had published an important series of theoretical memoirs1 as well as the results of experimental research of the first order4 ,in addition1 he had constructed new apparatus of great perfection--and all this in spite of very insufficient accommodations and resources4 ,this achievement suggests the distance he had traveled since the doubts and hesitations of his early youth in learning to discipline his methods of work1 and to derive from them the full advantage of his exceptional capacities4 ,he enjoyed a growing esteem in ,france1 and in foreign countries4 ,he was listened to with interest at the meetings of the learned societies 7,society of ,physics1 ,society of ,mineralogy1 ,society of ,electricians71 where he was in the habit of presenting his communications and where he joined readily in the discussion of various scientific questions4 ,among foreign scholars who already at this time appreciated him highly1 ,i can name1 in the first place1 the illustrious ,english physicist1 ,lord ,kelvin1 who joined with him in a certain scientific discussion1 and who often expressed for him1 from that time on1 both esteem and sympathy4 ,during one of his visits to ,paris1 ,lord ,kelvin was present at a meeting of the ,society of ,physics when ,pierre ,curie made a statement regarding the construction and the use of standard condensers with guard ring4 ,in this statement he recommended the use of an apparatus which involved the charging of the central part of the guard ring plate by a galvanic cell and in uniting the guard ring with the earth4 ,one uses then1 as a measure1 the charge induced on the second plate4 ,even though the resulting disposition of lines of the field be complex1 the charge induced can be calculated by a theorem of electrostatics1 with the same simple formula as is used for an ordinary apparatus in a uniform field1 and one has the benefit of a better isolation4 ,lord ,kelvin believed at first that this reasoning was inexact4 ,despite his great repute and his advanced age1 he went the following day to the laboratory to find the young ,director4 ,here he discussed the matter with him before the blackboard4 ,he was completely convinced1 and seemed even delighted to concede the point to his companion4#e ,it may seem astonishing that ,pierre ,curie1 in spite of his merits1 continued during twelve years in the small position of ,chief of ,laboratory4 ,without doubt this was largely due to the fact that it is easy to overlook those who have not the active support of influential persons4 ,it was due also to the fact that it was impossible for him to take the many steps that the pushing of any candidature involves4 ,then1 too1 his independence of character ill fitted him to ask for an advance1 and this notwithstanding the fact that his position was very modest4 ,indeed his salary1 then comparable to that of a day laborer 7about #cjj francs a month71 was scarcely sufficient to enable him to lead the simple life that would yet permit him to carry on his work4 ,he expressed his feelings on this subject in the following words3 ,i have heard that perhaps one of the professors will resign1 and that ,i might1 in that case1 make application to succeed him4 ,what an ugly necessity is this of seeking any position whatsoever2 ,i am not accustomed to this form of activity1 demoralizing to the highest degree4 ,i am sorry that ,i spoke to you about it4 ,i think that nothing is more unhealthy to the spirit than to allow oneself to be occupied by things of this character and to listen to the petty gossip that people come to report to you4 ,if he disliked soliciting an advancement in position1 he was even less inclined to hope for honors4 ,he had1 in fact1 a very decided opinion on the subject of honorary distinctions4 ,not only did he believe that they were not helpful1 but he considered them frankly harmful4 ,he felt that the desire to obtain them is a cause of trouble1 and that it can degrade the worthiest aim of man1 which is1 work for the pure love of it4 ,since he possessed great moral probity1 he did not hesitate to make his acts conform to his opinions4 ,when ,schtzenberger1 in order to offer him a mark of esteem1 wished to propose him for the ,palmes acadmiques he refused this distinction1 despite the advantages which1 according to general belief1 it would confer4 ,and he wrote to his director3 ,i have been informed that you intend to propose me again to the prefet for the decoration4 ,i pray you do not do so4 ,if you procure for me this honor1 you will place me under the necessity of refusing it1 for ,i have firmly decided not to accept a decoration of any kind4 ,i hope that you will be good enough to avoid taking a step that will make me appear a little ridiculous in the eyes of many people4 ,if your aim is to offer me a testimony of your interest1 you have already done that1 and in a very much more effective manner which touched me greatly1 for you have made it possible for me to work without worry4 ,faithful to this firm opinion1 he later declined the decoration of the ,lgion d',honneur1 which was offered him in #aijc4 ,but even though ,pierre ,curie refused to take steps to change his situation it was at last improved4 ,in #ahie the well-known physicist1 ,mascart1 professor in the ,collge de ,france1 impressed with his ability1 and with ,lord ,kelvin's opinion of him1 insisted that ,schtzenberger create a new ,chair of ,physics at the ,school of ,physics and ,chemistry4 ,pierre ,curie was then named professor under conditions in which his talents were duly recognized4 ,however1 nothing was done at this time to ameliorate the inadequate material conditions under which1 as we have already seen1 he was carrying on his personal investigations4 ,footnote #c3 ,in this very brief memoir is presented1 for the first time1 a theory which explains why crystals develop certain faces simultaneously1 in a particular direction1 and consequently why crystals possess a determined form4 ,footnote #d3 ,paramagnetic bodies are those which are magnetized in the same manner as iron1 either strongly 7ferro-magnetic7 or feebly4 ,diamagnetic bodies are those whose very feeble magnetization is opposed to that which iron takes in the same magnetic field4 ,footnote #e3 ,the following is the text of a letter from this distinguished savant to ,pierre ,curie1 written during one of his visits to ,paris3 ,october1 #ahic4 ,,dear ,,mr4 ,,curie3 ,i am much obliged to you for your letter of ,saturday and the information contained in it1 which is exceedingly interesting to me4 ,if ,i call at your laboratory between #aj and #aa tomorrow morning should ,i find you there8 ,there are two or three things ,i would like to speak to you about2 and ,i would like also to see more of your curves representing the magnetization of iron at different temperatures4 ,yours truly1 ,,kelvin4 ,,chapter ,,iv ,,marriage ,,and ,,organization ,,of ,,the ,,family ,,life4 ,,personality ,,and ,,character ,i met ,pierre ,curie for the first time in the spring of the year #ahid4 ,i was then living in ,paris where for three years ,i#f had been studying at the ,sorbonne4 ,i had passed the examinations for the licentiate in physics1 and was preparing for those in mathematics4 ,at the same time ,i had begun to work in the research laboratory of ,professor ,lippmann4 ,a ,polish physicist whom ,i knew1 and who was a great admirer of ,pierre ,curie1 one day invited us together to spend the evening with himself and his wife4 ,as ,i entered the room1 ,pierre ,curie was standing in the recess of a ,french window opening on a balcony4 ,he seemed to me very young1 though he was at that time thirty-five years old4 ,i was struck by the open expression of his face and by the slight suggestion of detachment in his whole attitude4 ,his speech1 rather slow and deliberate1 his simplicity1 and his smile1 at once grave and youthful1 inspired confidence4 ,we began a conversation which soon became friendly4 ,it first concerned certain scientific matters about which ,i was very glad to be able to ask his opinion4 ,then we discussed certain social and humanitarian subjects which interested us both4 ,there was1 between his conceptions and mine1 despite the difference between our native countries1 a surprising kinship1 no doubt attributable to a certain likeness in the moral atmosphere in which we were both raised by our families4 ,we met again at the ,physics ,society and in the laboratory4 ,then he asked if he might call upon me4 ,i lived at that time in a room on the sixth floor of a house situated near the schools4 ,it was a poor little room1 for my resources were extremely limited4 ,i was1 nevertheless1 very happy in it for ,i was now first realizing1 although already twenty-five years old1 the ardent desire ,i had so long cherished of carrying on advanced studies in science4 ,pierre ,curie came to see me1 and showed a simple and sincere sympathy with my student life4 ,soon he caught the habit of speaking to me of his dream of an existence consecrated entirely to scientific research1 and he asked me to share that life4 ,it was not1 however1 easy for me to make such a decision1 for it meant separation from my country and my family1 and the renouncement of certain social projects that were dear to me4 ,having grown up in an atmosphere of patriotism kept alive by the oppression of ,poland1 ,i wished1 like many other young people of my country1 to contribute my effort toward the conservation of our national spirit4 ,so matters stood1 when at the beginning of my vacation ,i left ,paris to go to my father in ,poland4 ,our correspondence during this separation helped to strengthen the bond of affection between us4 ,during the year #ahid ,pierre ,curie wrote me letters that seem to me admirable in their form4 ,no one of them was very long1 for he had the habit of concise expression1 but all were written in a spirit of sincerity and with an evident anxiety to make the one he desired as a companion know him as he was4 ,the very quality of the expression has always seemed to me remarkable4 ,no other one could describe in a few lines1 as he could1 a state of mind1 or a situation1 and by the simplest means make that description evoke a seizing image of truth4 ,because of this gift1 he might1 ,i believe1 have been a great writer4 ,i have already cited a few fragments of his letters1 and others will follow4 ,it is appropriate to quote here a few lines which express how he looked on the possibility of our marriage3 ,we have promised each other 7is it not true87 to have1 the one for the other1 at least a great affection4 ,provided that you do not change your mind6 ,for there are no promises which hold2 these are things that do not admit of compulsion4 ,it would1 nevertheless1 be a beautiful thing in which ,i hardly dare believe1 to pass through life together hypnotized in our dreams3 your dream for your country2 our dream for humanity2 our dream for science4 ,of all these dreams1 ,i believe the last1 alone1 is legitimate4 ,i mean to say by this that we are powerless to change the social order4 ,even if this were not true we should not know what to do4 ,and in working without understanding we should never be sure that we were not doing more harm than good1 by retarding some inevitable evolution4 ,from the point of view of science1 on the contrary1 we can pretend to accomplish something4 ,the territory here is more solid and obvious1 and however small it is1 it is truly in our possession4 ,i strongly advise you to return to ,paris in ,october4 ,i shall be very unhappy if you do not come this year1 but it is not my friend's selfishness that makes me ask you to return4 ,i ask it because ,i believe you will work better here and that you can accomplish here something more substantial and more useful4 ,one can understand1 from this letter1 that for ,pierre ,curie there was only one way of looking at the future4 ,he had dedicated his life to his dream of science3 he felt the need of a companion who could live his dream with him4 ,he told me many times that the reason he had not married until he was thirty-six was because he did not believe in the possibility of a marriage which would meet this1 his absolute necessity4 ,when he was twenty-two years old he wrote in his diary3 ,women1 much more than men1 love life for life's sake4 ,women of genius are rare4 ,and when1 pushed by some mystic love1 we wish to enter into a life opposed to nature1 when we give all our thoughts to some work which removes us from those immediately about us1 it is with women that we have to struggle1 and the struggle is nearly always an unequal one4 ,for in the name of life and of nature they seek to lead us back4 ,we can see1 however1 in the letters ,i have quoted earlier1 the unshakeable faith that ,pierre ,curie had in science and in its power to further the general good of humanity4 ,it seems appropriate to apply to him the sentiment expressed by ,pasteur in words so well known3 ,i believe invincibly that science and peace will triumph over ignorance and war4 ,this confidence in the solutions of science made ,pierre ,curie little inclined to take an active part in politics4 ,he was attached1 by education and by conviction1 to democratic and socialistic ideas1 but he was not dominated by any party doctrine4 ,however1 he always fulfilled1 as his father did1 his obligations as a voter4 ,in public life1 as in private life1 he was opposed to the use of violence4 ,what would you think1 he wrote me1 of a person who would knock his head against a stone wall with the intention of overthrowing it8 ,such an idea might be the result of very beautiful feelings1 but in realization it would be ridiculous and stupid4 ,i believe that certain questions demand a general solution1 and do not admit1 today1 of specific solutions1 and that one who begins a course that has no issue1 may do much harm4 ,i believe1 further1 that justice is not of this world1 and that the strongest system or rather the one best developed from the economic point of view will be that which will stand4 ,a man may exhaust himself by work1 and yet live1 at best1 miserably4 ,this is a revolting fact1 but it will not1 because of that1 cease4 ,it will disappear probably because man is a kind of machine1 and it is of economic advantage to make every machine work in its normal manner1 without forcing it4 ,he felt the same necessity for clarity and understanding in considering his own inner life as in examining a general problem4 ,a great necessity of loyalty to himself and toward others made him suffer from the compromises imposed by life1 even though he reduced them to a minimum4 ,we are all the slaves of our affections1 he wrote1 slaves of the prejudices of those we love4 ,besides1 we must make a living1 and this forces us to become a wheel in the machine4 ,the most painful are the concessions we are forced to make to the prejudices of the society in which we live4 ,we must make more or fewer compromises according as we feel ourselves feebler or stronger4 ,if one does not make enough concessions he is crushed2 if he makes too many he is ignoble and despises himself4 ,i find myself far from the principles ,i held ten years ago4 ,at that time ,i believed it necessary to be excessive in everything1 and to make no concessions whatsoever to one's environment4 ,i believed it necessary to exaggerate one's faults as well as one's virtues4 ,this was the credo of the man who1 without fortune himself1 desired to share his life with that of a student also without fortune1 whom he had met by chance4 ,after my return from my vacation our friendship grew more and more precious to us2 each realized that he or she could find no better life companion4 ,we decided1 therefore1 to marry1 and the ceremony took place in ,july1 #ahie4 ,in conformity with our mutual wish it was the simplest service possible1--a civil ceremony1 for ,pierre ,curie professed no religion1 and ,i myself did not practice any4 ,my husband's parents received me with great cordiality1 and reciprocally my father and my sisters1 who were present at our marriage1 were happy in knowing the family to which ,i was to belong4 ,our first home1 an extremely simple one1 consisted of a little apartment of three rooms in the rue de la ,glacire1 not far from the ,school of ,physics4 ,its chief attraction was its view of a large garden4 ,it was furnished very simply with objects that had belonged to our families4 ,our means did not permit our having servants1 so that ,i had to assume practically all the household duties1 as ,i had been in the habit of doing during my student days4 ,professor ,curie's salary was #fjjj francs a year1 and we held that he should not undertake any supplementary work1 at least in the beginning4 ,as for myself1 ,i was preparing to take the examination for the agregation of young women1 in view of obtaining a teaching post4 ,these ,i passed in #ahif4 ,we ordered our life to suit our scientific work and our days were passed in the laboratory1 where ,schtzenberger permitted that ,i might work with my husband4 ,he was then engaged in a research on the growth of crystals1 which interested him keenly4 ,he wished to know if certain faces of a crystal had a preferential development chiefly because they have a different rapidity of growth or because their solubility is different4 ,he quickly obtained interesting results 7not published7 but he had to interrupt his investigations to undertake others on radioactivity4 ,and he often regretted that he was never able to return to them4 ,i was occupied at this time with the study of the magnetization of tempered steel4 ,the preparation of his class lectures was for ,pierre ,curie a genuine care4 ,the ,chair was a new one1 and carried no prescribed course of study4 ,he divided his lectures1 at first1 between crystallography and electricity4 ,then1 as he recognized more and more the utility of a serious theoretical course in electricity for future engineers1 he devoted himself entirely to this subject1 and succeeded in establishing a course 7of about #abj lectures7 that was the most complete and modern then to be had in ,paris4 ,this cost him a considerable effort1 of which ,i was the daily witness2 for he was always anxious to give a complete picture of the phenomena and of the evolution of theories1 and of ideas4 ,he was always anxious1 too1 that his mode of exposition should be clear and precise4 ,he thought of publishing a treatise summing up this course1 but unfortunately the many preoccupations of the following years prevented him from putting this plan into execution4 ,we lived a very single life1 interested in common1 as we were1 in our laboratory experiments and in the preparation of lectures and examinations4 ,during eleven years we were scarcely ever separated1 which means that there are very few lines of existing correspondence between us1 representing that period4 ,we spent our rest days and our vacations walking or bicycling either in the country near ,paris1 or along the sea1 or in the mountains4 ,my husband was so engrossed in his researches1 however1 that it was very difficult for him to remain for any length of time in a place where he lacked facilities for work4 ,after a few days he would say3 ,it seems to me a very long time since we have accomplished anything4 ,and yet he liked the excursions which covered successive days1 and enjoyed to the full our walks together1 just as he had formerly enjoyed those with his brother4 ,but his joy in seeing beautiful things never drew his thoughts away from the scientific questions that absorbed him4 ,in these free times1 we traversed the region of the ,cevennes and of the ,monts d',auvergne1 as well as the coast of ,france1 and some of its great forests4 ,these days in the open1 filled with beautiful sights1 made a deep impression on us1 and we loved to recall them4 ,one of our radiant memories was of a sunny day1 when after a long and wearying climb1 we reached the fresh1 green meadow of the ,aubrac1 in the pure air of the high plateaus4 ,another vivid memory was that of an evening1 when1 lingering until twilight in the gorge of the ,truyre1 we were enchanted to hear a popular air dying away in the distance1 carried to us from a little boat that descended the stream4 ,we had taken so little notice of the time that we did not regain our lodging before dawn4 ,at one point we had an encounter with carts whose horses were frightened by our bicycles1 and we were obliged to cut across ploughed fields4 ,at length we regained our route on the high plateau1 bathed in the unreal light of the moon4 ,and cows that were passing the night in enclosures came gravely to contemplate us with their large1 tranquil eyes4 ,the forest of ,compiegne charmed us in the spring1 with its mass of green foliage stretching far as the eye could see1 and its periwinkles and anemones4 ,on the border of the forest of ,fontainebleau1 the banks of the ,loing1 covered with water buttercups1 were an object of delight for ,pierre ,curie4 ,we loved the melancholy coasts of ,brittany and the reaches of heather and gorse1 stretching to the very points of ,finistre1 which seemed like claws or teeth burying themselves in the water which forever rages at them4 ,later1 when we had our baby with us1 we passed our vacations in some one locality1 without traveling about4 ,we lived then as simply as possible in retired villages where we could scarcely be distinguished from the villagers themselves4 ,i remember the stupefaction of an ,american journalist when he found us one day at ,pouldu1 at a moment when ,i was sitting on one of the stone steps of our house in the act of shaking the sand from my sandals4 ,however1 his embarrassment was short-lived and1 adapting himself to the situation1 he sat down beside me and began jotting down in his notebook my answers to his questions4 ,the most affectionate relations existed between my husband's parents and myself4 ,we often went to ,sceaux1 where the room my husband used to have before our marriage was always reserved for us4 ,i had also a very tender affection for ,jacques ,curie and his family 7he was married and had two children72 for ,pierre's brother became mine1 and has always remained so4 ,our eldest daughter1 ,irene1 was born in ,september1 #ahig1 and only a few days afterwards my husband suffered a great loss in the death of his mother4 ,doctor ,curie came to live with us in a house which had a garden and was situated on the old fortifications of ,paris 7#ajh ,boulevard ,kellermann7 near the park of ,montsouris4 ,pierre ,curie lived in this house until the end of his life4 ,with the birth of our child1 the difficulties of carrying on our work were augmented3 for ,i had to give more time to the household4 ,very fortunately for us ,i could leave my little girl with her grandfather1 who much enjoyed taking care of her4 ,but we had to think also of increasing our resources to meet the needs of our larger family and to enable us to secure someone to help me in the house1 a necessity from now on4 ,however1 our situation remained as it was during the following two years1 which we consecrated to intensive laboratory research on radioactivity4 ,it was1 indeed1 not relieved until #aijj1 to the detriment1 it is true1 of the amount of time we could give to our investigations4 ,all formal social obligations were excluded from our life4 ,pierre ,curie had for such things an unconquerable repugnance4 ,neither in his earlier nor his later life would he pay visits or undertake to involve himself in relations without special interest4 ,by nature grave and silent1 he preferred to abandon himself to his own reflections1 rather than to engage in an exchange of banal words4 ,on the other hand1 he valued greatly his boyhood friends1 and those to whom he was bound by a common interest in science4 ,among the latter1 ,e4 ,gouy1 professor of the faculty of sciences at ,lyon1 should be named4 ,his friendly relations with ,pierre ,curie dated from the time when they were both preparators at the ,sorbonne4 ,they carried on regularly a scientific correspondence1 and took great pleasure in seeing each other again during the various brief visits of ,e4 ,gouy to ,paris1 on which occasions they were inseparable4 ,there existed also a friendship of long standing between my husband and ,ch4 ,ed4 ,guillaume1 now director of the ,international ,bureau of ,weights and ,measures of ,svres4 ,they met at the ,physics ,society and occasionally on ,sundays at ,svres or ,sceaux4 ,later a group of younger men formed themselves about ,pierre ,curie4 ,they were investigators engaged1 as he was1 in physical and chemical research in the newest fields of these sciences4 ,among these men were ,andr ,debierne1 my husband's intimate friend and collaborator in the work on radioactivity2 ,george ,sagnac1 his collaborator in a study of the ,x-rays2 ,paul ,langevin1 who became a professor in the ,collge de ,france2 ,jean ,perrin1 at present professor of physical chemistry in the ,sorbonne2 and ,georges ,urbain1 student of the ,school of ,physics and later professor in the ,sorbonne4 ,often one or the other came to see us in our quiet house in the ,boulevard ,kellermann4 ,then we engaged in discussions of recent or future experiments1 or of new ideas and theories1 and never tired of rejoicing over the marvelous development of modern physics4 ,there were not many large reunions in our house1 for my husband did not feel the need of them4 ,he was more at his ease in a conversation with some one or few persons1 and rarely attended any meetings except those of the scientific societies4 ,if by chance he found himself in a gathering where the general conversation did not interest him1 he took refuge in a tranquil corner where he could forget the company as he pursued his own thoughts4 ,our relations with our families were very restricted on his side as on mine2 for he had few relatives and mine were far away4 ,he was1 however1 very devoted to those of my family who could come to visit me in ,paris1 or during our vacations4 ,in #ahii1 ,pierre ,curie made a journey with me to the ,carpathians of ,austrian ,poland1 where one of my sisters1 married to ,doctor ,dluski and herself a physician1 directed1 with him1 a large sanatorium4 ,through a touching desire to know all that was dear to me1 my husband1 though he knew little of foreign languages1 wished to learn ,polish1 something which ,i had not thought of suggesting because ,i did not believe it could prove sufficiently useful to him4 ,he felt a sincere sympathy for my country and believed in the future ,establishment of a free ,poland4 ,in our life together it was given to me to know him as he had hoped ,i might1 and to penetrate each day further into his thought4 ,he was as much and much more than all ,i had dreamed at the time of our union4 ,my admiration of his unusual qualities grew continually2 he lived on a plane so rare and so elevated that he sometimes seemed to me a being unique in his freedom from all vanity and from the littlenesses that one discovers in oneself and in others1 and which one judges with indulgence although aspiring to a more perfect ideal4 ,in this lay1 without doubt1 the secret of that infinite charm of his to which one could not long rest insensible4 ,his thoughtful expression and the directness of his look were strongly attractive and this attraction was increased by his kindliness and gentleness of character4 ,he sometimes said that he never felt combative1 and this was entirely true4 ,one could not enter into a dispute with him because he could not become angry4 ,getting angry is not one of my strong points1 he would say1 smiling4 ,if he had few friends1 he had no enemies2 for he could not injure anyone1 even by inadvertence4 ,but at the same time no one could force him to deviate from his line of action1 something which led his father to nickname him the gentle stubborn one4 ,when he expressed his opinion he did so frankly1 for he was convinced that diplomatic methods are puerile1 and that directness is at once easiest and best4 ,because of this practice1 he acquired a certain reputation for navet2 in reality he was acting on a well-considered decision1 rather than by instinct4 ,it was perhaps because he was able to judge himself and to retire within himself1 that he was so capable of clearly appreciating the springs of action1 the intention1 and the thoughts of others4 ,and if he sometimes neglected details1 he was rarely deceived in the essentials4 ,usually he kept his sure judgments to himself2 but once he had made up his mind he sometimes expressed them without reticence1 in the assurance that he was doing something useful4 ,in his scientific relations he showed no sharpness1 and did not permit himself to be influenced by considerations of personal credit or by personal sentiments4 ,every beautiful success gave him pleasure1 even if achieved in a domain where he felt himself to have priority4 ,he said3 ,what does it matter if ,i have not published such and such investigations1 if another has published them8 ,for he held that in science we should be interested in things and not in persons4 ,he was so genuinely against every form of emulation that he opposed even the competitions and gradings of the lyces1 as well as all forms of honorary distinction4 ,he never failed to give counsel and encouragement to any of those who showed an aptitude for science1 and certain among them still remain profoundly grateful to him4 ,if his attitude was that of one of the lite who have attained the highest summit of civilization1 his acts were those of a truly good man endowed with the sentiment of human solidarity intimately bound to his intellectual conceptions1 and full of understanding and indulgence4 ,he was always ready to aid1 as far as his means allowed1 any person in a difficult situation1 even if helping meant giving some of his time1 which was always the greatest sacrifice he could make4 ,his generosity was so spontaneous that one scarcely noticed it4 ,he believed that the only advantage of material means1 beyond that of providing the necessities of a simple life1 was in the opportunity they offered of aiding others1 and of pursuing the work of one's preference4 ,what shall ,i say1 finally1 of his love for his own1 and of his qualities as friend8 ,his friendship1 which he gave rarely1 was sure and faithful1 for it rested on a community of ideas and opinions4 ,and still more rarely did he give affection2 but how complete was his gift to his brother and to me6 ,he could forsake his customary reserve for an unconstraint which established harmony and confidence4 ,his tenderness was the most exquisite of blessings1 sure and helpful1 full of gentleness and solicitude4 ,it was good to be surrounded by this tenderness2 it was cruel to lose it after having lived in an atmosphere completely permeated by it4 ,but ,i will let his own words tell how completely he gave himself3 ,i think of you who fill my life1 and ,i long for new powers4 ,it seems to me that in concentrating my mind exclusively upon you1 as ,i am doing1 that ,i should succeed in seeing you1 and in following what you are doing2 and that ,i should be able to make you feel that ,i am altogether yours at this moment1--but the image does not come4 ,we were not warranted in having great confidence in our health1 nor in our strength so often put to severe tests4 ,and from time to time1 as happens to those who know the value of sharing a common life1 the fear of the irreparable touched our minds4 ,in such moments his simple courage led him always to the same inevitable conclusion3 ,whatever happens1 even if one should become like a body without a soul1 still one must always work4 ,footnote #f3 ,the following are a few brief biographical details3 ,my name is ,marie ,sklodowska4 ,my father and mother belonged to ,catholic ,polish families4 ,both were teachers in secondary schools in ,warsaw 7at that time under ,russia74 ,i was born in ,warsaw and attended a lyce there4 ,following the lyce1 ,i taught several years4 ,then in #ahib ,i came to ,paris in order to study science4 ,,chapter ,v ,,the ,,dream ,,become ,a ,,reality4 ,,the ,,discovery ,,of ,,radium ,i have already said that in #ahig ,pierre ,curie was occupied with an investigation on the growth of crystals4 ,i myself had finished1 by the beginning of vacation1 a study of the magnetization of tempered steels which had resulted in our getting a small subvention from the ,society for the ,encouragement of ,national ,industry4 ,our daughter ,irene was born in ,september1 and as soon as ,i was well again1 ,i resumed my work in the laboratory with the intention of preparing a doctor's thesis4 ,our attention was caught by a curious phenomenon discovered in #ahif by ,henri ,becquerel4 ,the discovery of the ,x-ray by ,roentgen had excited the imagination1 and many physicians were trying to discover if similar rays were not emitted by fluorescent bodies under the action of light4 ,with this question in mind ,henri ,becquerel was studying uranium salts1 and1 as sometimes occurs1 came upon a phenomenon different from that he was looking for3 the spontaneous emission by uranium salts of rays of a peculiar character4 ,this was the discovery of radioactivity4 ,the particular phenomenon discovered by ,becquerel was as follows3 uranium compound placed upon a photographic plate covered with black paper produces on that plate an impression analogous to that which light would make4 ,the impression is due to uranium rays that traverse the paper4 ,these same rays can1 like ,x-rays1 discharge an electroscope1 by making the air which surrounds it a conductor4 ,henri ,becquerel assured himself that these properties do not depend on a preliminary isolation1 and that they persist when the uranium compound is kept in darkness during several months4 ,the next step was to ask whence came this energy1 of minute quantity1 it is true1 but constantly given off by uranium compounds under the form of radiations4 ,the study of this phenomenon seemed to us very attractive and all the more so because the question was entirely new and nothing yet had been written upon it4 ,i decided to undertake an investigation of it4 ,it was necessary to find a place in which to conduct the experiments4 ,my husband obtained from the director of the ,school the authorization to use a glassed-in study on the ground floor which was then being used as a storeroom and machine shop4 ,illustration3 ,henri ,manuel1 ,paris4 ,pierre and ,marie ,curie in their laboratory1 where radium was discovered4 ,in order to go beyond the results reached by ,becquerel1 it was necessary to employ a precise quantitative method4 ,the phenomenon that best lent itself to measurement was the conductibility produced in the air by uranium rays4 ,this phenomenon1 which is called ionization1 is produced also by ,x-rays and investigation of it in connection with them had made known its principal characteristics4 ,for measuring the very feeble currents that one can make pass through air ionized by uranium rays1 ,i had at my disposition an excellent method developed and applied by ,pierre and ,jacques ,curie4 ,this method consists in counterbalancing on a sensitive electrometer the quantity of electricity carried by the current with that which a piezo-electric quartz can furnish4 ,the installation therefore required a ,curie electrometer1 a piezo-electric quartz1 and a chamber of ionization1 which last was formed by a plate condenser whose higher plate was joined to the electrometer1 while the lower plate1 charged with a known potential1 was covered with a thin layer of the substance to be examined4 ,needless to say1 the place for such an electrometric installation was hardly the crowded and damp little room in which ,i had to set it up4 ,my experiments proved that the radiation of uranium compounds can be measured with precision under determined conditions1 and that this radiation is an atomic property of the element of uranium4 ,its intensity is proportional to the quantity of uranium contained in the compound1 and depends neither on conditions of chemical combination1 nor on external circumstances1 such as light or temperature4 ,i undertook next to discover if there were other elements possessing the same property1 and with this aim ,i examined all the elements then known1 either in their pure state or in compounds4 ,i found that among these bodies1 thorium compounds are the only ones which emit rays similar to those of uranium4 ,the radiation of thorium has an intensity of the same order as that of uranium1 and is1 as in the case of uranium1 an atomic property of the element4 ,it was necessary at this point to find a new term to define this new property of matter manifested by the elements of uranium and thorium4 ,i proposed the word radioactivity which has since become generally adopted2 the radioactive elements have been called radio elements4 ,during the course of my research1 ,i had had occasion to examine not only simple compounds1 salts and oxides1 but also a great number of minerals4 ,certain ones proved radioactive2 these were those containing uranium and thorium2 but their radioactivity seemed abnormal1 for it was much greater than the amount ,i had found in uranium and thorium had led me to expect4 ,this abnormality greatly surprised us4 ,when ,i had assured myself that it was not due to an error in the experiment1 it became necessary to find an explanation4 ,i then made the hypothesis that the ores uranium and thorium contain in small quantity a substance much more strongly radioactive than either uranium or thorium4 ,this substance could not be one of the known elements1 because these had already been examined2 it must1 therefore1 be a new chemical element4 ,i had a passionate desire to verify this hypothesis as rapidly as possible4 ,and ,pierre ,curie1 keenly interested in the question1 abandoned his work on crystals 7provisionally1 he thought7 to join me in the search for this unknown substance4 ,we chose1 for our work1 the ore pitchblende1 a uranium ore1 which in its pure state is about four times more active than oxide of uranium4 ,since the composition of this ore was known through very careful chemical analysis1 we could expect to find1 at a maximum1 #a per cent of new substance4 ,the result of our experiment proved that there were in reality new radioactive elements in pitchblende1 but that their proportion did not reach even a millionth per cent6 ,the method we employed is a new method in chemical research based on radioactivity4 ,it consists in inducing separation by the ordinary means of chemical analysis1 and of measuring1 under suitable conditions1 the radioactivity of all the separate products4 ,by this means one can note the chemical character of the radioactive element sought for1 for it will become concentrated in those products which will become more and more radioactive as the separation progresses4 ,we soon recognized that the radioactivity was concentrated principally in two different chemical fractions1 and we became able to recognize in pitchblende the presence of at least two new radioactive elements3 polonium and radium4 ,we announced the existence of polonium in ,july1 #ahih1 and of radium in ,december of the same year4#g ,in spite of this relatively rapid progress1 our work was far from finished4 ,in our opinion1 there could be no doubt of the existence of these new elements1 but to make chemists admit their existence1 it was necessary to isolate them4 ,now1 in our most strongly radioactive products 7several hundred times more active than uranium71 the polonium and radium were present only as traces4 ,the polonium occurred associated with bismuth extracted from pitchblende1 and radium accompanied the barium extracted from the same mineral4 ,we already knew by what methods we might hope to separate polonium from bismuth and radium from barium2 but to accomplish such a separation we had to have at our disposition much larger quantities of the primary ore than we had4 ,it was during this period of our research that we were extremely handicapped by inadequate conditions1 by the lack of a proper place to work in1 by the lack of money and of personnel4 ,pitchblende was an expensive mineral1 and we could not afford to buy a sufficient quantity4 ,at that time the principal source of this mineral was at ,st4 ,joachimsthal 7,bohemia7 where there was a mine which the ,austrian government worked for the extraction of uranium4 ,we believed that we would find all the radium and a part of the polonium in the residues of this mine1 residues which had so far not been used at all4 ,thanks to the influence of the ,academy of ,sciences of ,vienna1 we secured several tons of these residues at an advantageous price1 and we used it as our primary material4 ,in the beginning we had to draw on our private resources to pay the costs of our experiment2 later we were given a few subventions and some help from outside sources4 ,the question of quarters was particularly serious2 we did not know where we could conduct our chemical treatments4 ,we had been obliged to start them in an abandoned storeroom across a court from the workroom where we had our electrometric installation4 ,this was a wooden shed with a bituminous floor and a glass roof which did not keep the rain out1 and without any interior arrangements4 ,the only objects it contained were some worn pine tables1 a cast-iron stove1 which worked badly1 and the blackboard which ,pierre ,curie loved to use4 ,there were no hoods to carry away the poisonous gases thrown off in our chemical treatments1 so that it was necessary to carry them on outside in the court1 but when the weather was unfavorable we went on with them inside1 leaving the windows open4 ,illustration3 ,a view of the extraction of radium in the old shed where the first radium was obtained4 ,in this makeshift laboratory we worked practically unaided during two years1 occupying ourselves as much with chemical research as with the study of the radiation of the increasingly active products we were obtaining4 ,then it became necessary for us to divide our work4 ,pierre ,curie continued the investigations on the properties of radium1 while ,i went ahead with the chemical experiments which had as their objective the preparation of pure radium salts4 ,i had to work with as much as twenty kilogrammes of material at a time1 so that the hangar was filled with great vessels full of precipitates and of liquids4 ,it was exhausting work to move the containers about1 to transfer the liquids1 and to stir for hours at a time1 with an iron bar1 the boiling material in the cast-iron basin4 ,i extracted from the mineral the radium-bearing barium and this1 in the state of chloride1 ,i submitted to a fractional crystallization4 ,the radium accumulated in the least soluble parts1 and ,i believed that this process must lead to the separation of the chloride of radium4 ,the very delicate operations of the last crystallizations were exceedingly difficult to carry out in that laboratory1 where it was impossible to find protection from the iron and coal dust4 ,at the end of a year1 results indicated clearly that it would be easier to separate radium than polonium2 that is why we concentrated our efforts in this direction4 ,we examined the radium salts we obtained with the aim of discovering their powers and we loaned samples of the salts to several scientists1#h in particular to ,henri ,becquerel4 ,during the years #ahii and #aijj1 ,pierre ,curie published with me a memoir on the discovery of the induced radioactivity produced by radium4 ,we published another paper on the effects of the rays3 the luminous effects1 the chemical effects1 etc42 and still another on the electric charge carried by certain of the rays4 ,and1 finally1 we made a general report on the new radioactive substances and their radiations1 for the ,congress of ,physics which met in ,paris in #aijj4 ,my husband published1 besides1 a study of the action of a magnetic field on radium rays4 ,illustration3 ,pierre ,curie with the quartz piezo-electroscope he invented1 by which rays of radium are measured4 ,the main result of our investigations and of those of other scientists during these years1 was to make known the nature of the rays emitted by radium1 and to prove that they belonged to three different categories4 ,radium emits a stream of active corpuscles moving with great speed4 ,certain of them carry a positive charge and form the ,alpha rays2 others1 much smaller1 carry a negative charge and form ,beta rays4 ,the movements of these two groups are influenced by a magnet4 ,a third group is constituted by the rays that are insensible to the action of a magnet1 and that1 we know to-day1 are a radiation similar to light and to ,x-rays4 ,we had an especial joy in observing that our products containing concentrated radium were all spontaneously luminous4 ,my husband who had hoped to see them show beautiful colorations had to agree that this other unhoped-for characteristic gave him even a greater satisfaction than that he had aspired to4 ,the ,congress of #aijj offered us an opportunity to make known1 at closer range1 to foreign scientists1 our new radioactive bodies4 ,this was one of the points on which the interest of this ,congress chiefly centered4 ,we were at this time entirely absorbed in the new field that opened before us1 thanks to the discovery so little expected4 ,and we were very happy in spite of the difficult conditions under which we worked4 ,we passed our days at the laboratory1 often eating a simple student's lunch there4 ,a great tranquillity reigned in our poor1 shabby hangar2 occasionally1 while observing an operation1 we would walk up and down talking of our work1 present and future4 ,when we were cold1 a cup of hot tea1 drunk beside the stove1 cheered us4 ,we lived in a preoccupation as complete as that of a dream4 ,sometimes we returned in the evening after dinner for another survey of our domain4 ,our precious products1 for which we had no shelter1 were arranged on tables and boards2 from all sides we could see their slightly luminous silhouettes1 and these gleamings1 which seemed suspended in the darkness1 stirred us with ever new emotion and enchantment4 ,actually1 the employees of the ,school owed ,pierre ,curie no service4 ,but nevertheless the laboratory helper whom he had had to aid him when he was laboratory chief had always continued to help him as much as he could in the time at his disposal4 ,this good man1 whose name was ,petit1 felt a real affection and solicitude for us1 and many things were made easier because of his good will and the interest he took in our success4 ,illustration3 ,a view of the extraction of radium in the old shed where the first radium was obtained4 ,we had begun our research in radioactivity quite alone1 but because of the magnitude of the undertaking1 we were more and more convinced of the utility of inviting collaboration4 ,already in #ahih1 one of the laboratory chiefs of the ,school1 ,g4 ,bemont1 had given us temporary aid4 ,and toward #aijj ,pierre ,curie associated with him a young chemist1 ,andr ,debierne1 preparator under ,friedel1 who held him in high esteem4 ,andr ,debierne gladly accepted ,pierre ,curie's proposal that he occupy himself with the investigation of radioactivity2 and he undertook1 in particular1 the search for a new radio element1 which we suspected existed in the iron group and in rare earths4 ,he discovered the element actinium4 ,even though he carried on his work in the laboratory of physical chemistry at the ,sorbonne1 directed by ,jean ,perrin1 he frequently came to visit us in our storeroom1 and was soon an intimate friend of ours1 and of ,doctor ,curie and the children4 ,about this same time1 ,george ,sagnac1 a young physicist engaged in the study of ,x-rays1 often came to discuss with my husband the analogies one could expect to find between these rays1 and their secondary rays1 and the radiations of radioactive bodies4 ,they worked together on the investigation of the electric charge carried by the secondary rays4 ,besides our collaborators we saw very few persons in the laboratory2 however1 from time to time some physicist or chemist came to see our experiments1 or to ask ,pierre ,curie for advice or information2 for his authority in several branches of physics was very well recognized4 ,and then there were discussions before the blackboard1--discussions which are pleasantly remembered to-day1 because they stimulated an interest in science and an ardor for work without interrupting any course of reflection1 and without troubling that atmosphere of peace and contemplation which is the true atmosphere of the laboratory4 ,footnote #g3 ,this last publication was issued in common with ,g4 ,bemont1 who had collaborated with us in our experiments4 ,footnote #h3 ,i quote1 as an example1 a letter addressed to ,pierre ,curie by ,a4 ,paulsen1 thanking him for radioactive products loaned him in #ahii3 ,den ,damke ,nordl's ,expedition ,akureyi1 #af ,oct4 #ahii4 ,monsieur1 and most honored colleague1 ,i thank you warmly for your letter of ,august #a1 which ,i have just received in the north of ,iceland4 ,we have abandoned all the methods hitherto employed to establish in a fixed conductor the potential that exists at certain points in the mass of air that surrounds it1 and are using only your radiant powder4 ,accept1 ,monsieur1 and most honored colleague1 my respectful salutations and my renewed thanks for the great services you have rendered my expedition4 ,,adam ,,paulsen4 ,,chapter ,,vi ,,the ,,struggle ,,for ,,means ,,to ,,work4 ,,the ,,burden ,,of ,,celebrity4 ,,the ,,first ,,assistance ,,from ,,the ,,state4 ,,it ,,comes ,,too ,,late ,in spite of our desire to concentrate our entire effort on the work in which we were engaged1 and in spite of the fact that our needs were so modest1 we were forced to recognize1 toward #aijj1 that some increase in our income was indispensable4 ,pierre ,curie had few illusions about his chances of obtaining an important chair in the ,university of ,paris1 which would1 even though it meant no large salary1 have sufficed for the small needs of our family1 and enabled us to live without a supplementary revenue4 ,since he was neither a graduate of the ,normal ,school nor of the ,polytechnic1 he lacked the support1 often decisive1 which these big schools give their pupils2 and the posts to which he might justly have aspired1 because of his achievements1 were given to others1 without anyone's even thinking of him as a possible candidate4 ,at the beginning of #ahih1 he asked1 without success1 for the ,chair of ,physical ,chemistry left vacant by the death of ,salet1 and this failure convinced him that he had no chance of advancement4 ,he was appointed1 however1 in ,march1 #aijj1 to the position of assistant professor 7rptiteur7 in the ,polytechnic ,school1 but he kept his post only six months4 ,in the spring of #aijj1 there came an unexpected offer1 that of the ,chair of ,physics in the ,university of ,geneva4 ,the doyen of that ,university made the invitation in the most cordial manner1 and insisted that the ,university was ready to make an exceptional effort to secure a scientist of such high repute4 ,the advantages of this position were that the salary was larger than the average one1 that it carried the promise of the development of a ,physics ,laboratory adequate to our needs1 and that an official position for me would be provided in this laboratory4 ,such a proposition merited a most careful consideration1 so we made a visit to the ,university of ,geneva1 where our reception was the most encouraging possible4 ,this was a grave decision for us to make4 ,geneva presented material advantages1 and the opportunity of a life comparable in its tranquillity with that in the country4 ,pierre ,curie was1 therefore1 tempted to accept1 and it was only our immediate interest in our researches in radium that made him finally decide not to4 ,he feared the interruption of our investigations which such a change must involve4 ,at this moment the ,chair of ,physics in the physics1 chemistry and natural history course at the ,sorbonne1 obligatory for students of medicine1 and familiarly known as ,p4,c4,n41 was vacant2 he applied1 and was appointed1 due to the influence of ,henri ,poincar1 who was anxious to free him from the necessity of quitting ,france4 ,at the same time ,i was given charge of the physics lectures in the ,normal ,school for ,girls at ,svres4 ,so we remained in ,paris1 and with our income increased4 ,but we were at the same time working under increasingly difficult conditions4 ,pierre ,curie was doing double teaching2 and that in the ,p4,c4,n41 with its very large number of students1 fatigued him greatly4 ,as for myself1 ,i had to give much time to the preparation of my lectures at ,svres1 and to the organization of the laboratory work there1 which ,i found very insufficient4 ,moreover1 ,pierre ,curie's new position did not bring with it a laboratory2 a little office and a single work room were all that he had at his disposition in the annex 7#ab rue ,cuvier7 of the ,sorbonne1 which served as teaching quarters for the ,p4,c4,n4 ,and yet he felt it absolutely necessary to go ahead with his own work4 ,in fact1 the rapid extension of his investigations in radioactivity had made him determine that in his new position at the ,sorbonne he would receive students and start them in research4 ,he therefore took steps to find larger available working quarters4 ,those who have taken similar steps realize the wall of financial and administrative obstacles against which he was throwing himself1 and realize the large number of official letters1 visits1 and of requests the least success entailed4 ,all this thoroughly wearied and discouraged ,pierre ,curie4 ,he was obliged1 too1 constantly1 to keep traveling back and forth between the laboratories of the ,p4,c4,n4 and the hangar of the ,school of ,physics where we still continued our work4 ,and besides these difficulties1 we found that we could not make further progress without the aid of industrial means of treating our raw material4 ,fortunately certain expedients and generous assistance solved this question4 ,as early as #ahii ,pierre ,curie succeeded in organizing a first industrial experiment1 using for it a chance installation placed at his disposition by the ,central ,society of ,chemical ,products1 with which he had had relations in connection with the construction of his balances4 ,the technical details had been arranged very successfully by ,andr ,debierne1 and the operations brought good results1 even though it had been necessary to train a special personnel for this chemical work which demanded special precautions4 ,our investigations had started a general scientific movement1 and similar work was being undertaken in other countries4 ,toward these efforts ,pierre ,curie maintained a most disinterested and liberal attitude4 ,with my agreement he refused to draw any material profit from our discovery4 ,we took no copyright1 and published without reserve all the results of our research1 as well as the exact processes of the preparation of radium4 ,in addition1 we gave to those interested whatever information they asked of us4 ,this was of great benefit to the radium industry1 which could thus develop in full freedom1 first in ,france1 then in foreign countries1 and furnish to scientists and to physicians the products which they needed4 ,this industry still employs to-day1 with scarcely any modifications1 the processes indicated by us4#i ,even though our industrial experiment yielded good results1 again our slender resources made it difficult to make further progress4 ,inspired by our attempt1 a ,french industrial1 ,armet de ,lisle1 had the idea1 which seemed daring at that epoch1 of founding a veritable radium factory that would furnish this product to physicians1 whose interest in the biological effects of radium and its possible therapeutic applications had been aroused by the publication of various investigations4 ,the project proved a success because he could employ men already trained by us in the delicate processes of this manufacture4 ,radium was then regularly placed on sale1 at a high price1 it is true1 because of the special conditions under which it had to be made1 and because1 too1 of the immediate rise in the cost of the minerals necessary to its production4#aj ,i should like to express1 here1 our appreciation of the spirit in which ,armet de ,lisle offered to cooperate with us4 ,in an entirely disinterested manner he placed at our disposition a little working place in his factory and a part of the means necessary for us to use it4 ,other funds were added either by ourselves1 or came through subventions1 of which the most important1 accorded in #aijb by the ,academy of ,sciences1 amounted to #bj1jjj francs4 ,it was in this way that we were able to utilize the ore we had acquired little by little in the preparation of a certain quantity of radium1 which we used constantly in our research4 ,the radium-bearing barium was extracted in the factory1 and ,i carried on its purification and fractional crystallization in the laboratory4 ,in #aijb ,i succeeded in preparing a decigramme of chloride of pure radium which gave only the spectrum of the new element1 radium4 ,i made a first determination of the atomic weight of this new element1 an atomic weight much higher than that of barium4 ,thus the chemical individuality of radium was completely established1 and the reality of radioelements was a known fact about which there could be no further controversy4 ,i based my doctor's thesis1 presented in #aijc1 on these investigations4 ,later1 the quantity of radium extracted for the laboratory was increased1 and in #aijg ,i was able to make a second and more precise determination of the atomic weight as #bbe4ce--one accepts now the number #bbf4 ,i succeeded1 too1 jointly with ,andr ,debierne1 in obtaining radium in the state of metal4 ,the total quantity of radium ,i prepared and gave to the laboratory1 in agreement with ,pierre ,curie's desire1 amounted to more than a gramme of radium element4 ,the activity of pure radium exceeded all our expectations4 ,for equal weights this substance emits a radiation more than a million times more intense than uranium4 ,to offset this1 the quantity of radium contained in uranium minerals is scarcely more than three decigrammes of radium to the ton of uranium4 ,there is a very close relation between these two substances4 ,in fact1 we know to-day that radium is produced in the minerals at the expense of uranium4 ,the years that followed his nomination to the ,p4,c4,n4 were hard for ,pierre ,curie4 ,he had to face the many anxieties incident to the organization of a complicated system of work when his happiness depended on his being able to concentrate his efforts on a single determined subject4 ,the physical fatigue due to the numerous courses he was obliged to give was so great that he suffered from attacks of acute pain1 which in his overtaxed condition became more and more frequent4 ,it was therefore vitally important1 if he was to spare his energy and keep his health1 that the burden of his professional duties be lightened4 ,he decided to apply for the ,chair of ,mineralogy1 which was vacant1 at the ,sorbonne1 for which he was entirely qualified because of his profound knowledge and his important publications on the theories of the physics of crystals4 ,yet his candidacy failed4 ,during this painful period he nevertheless managed1 by a truly superhuman effort1 successfully to complete and publish several investigations that he had made either alone or in collaboration3 ,investigations on induced radioactivity 7in collaboration with ,a4 ,debierne74 ,investigations on the same subject 7in collaboration with ,j4 ,danne74 ,investigations on the conductibility provoked in dielectric liquids by the rays of radium and the ,roentgen rays4 ,investigations on the law of the decrease of the emanation of radium and on the radioactive constants that characterize this emanation and its active deposit4 ,discovery of the liberation of heat produced by radium 7in collaboration with ,a4 ,laborde74 ,investigations on the diffusion of the emanation of radium in the air 7in collaboration with ,j4 ,danne74 ,investigation on the radioactivity of gases from thermal springs 7in collaboration with ,a4 ,laborde74 ,investigation on the physiological effects of radium rays 7in common with ,henri ,becquerel74 ,investigation on the physiological action of the radium emanation 7in common with ,bouchard and ,balthazard74 ,notes on the apparatus for the determination of magnetic constants 7in common with ,c4 ,cheneveau74 ,all these investigations in radioactivity are fundamental and touch very varied subjects4 ,several have as their aim the study of the emanation1 that strange gaseous body that radium produces and which is largely responsible for the intense radiation commonly attributed to the radium itself4 ,pierre ,curie demonstrated by a searching examination the rigorous and invariable law according to which the emanation destroys itself1 no matter what the conditions are in which it finds itself4 ,to-day the emanation of radium1 harvested in tiny phials1 is commonly employed by physicians as a therapeutic agent4 ,technical considerations make its employment preferable to the direct use of radium1 and in this case no physician can proceed without consulting the numerical chart which tells how much of this emanation has disappeared each day1 despite the fact that it is cloistered in its little glass prison4 ,it is this same emanation that is found in small quantities in mineral waters1 and that plays a part in their curative effects4 ,more striking still was the discovery of the discharge of heat from radium4 ,without any alteration in appearance this substance releases each hour a quantity of heat sufficient to melt its own weight of ice4 ,when well protected against this external loss1 radium heats itself4 ,its temperature can rise #aj degrees or more above that of the surrounding atmosphere4 ,this defied all contemporary scientific experience4 ,finally1 ,i cannot pass in silence1 because of their various repercussions1 the experiments connected with the physiological effects of radium4 ,in order to test the results that had just been announced by ,f4 ,giesel1 ,pierre ,curie voluntarily exposed his arm to the action of radium during several hours4 ,this resulted in a lesion resembling a burn1 that developed progressively and required several months to heal4 ,henri ,becquerel had by accident a similar burn as a result of carrying in his vest pocket a glass tube containing radium salt4 ,he came to tell us of this evil effect of radium1 exclaiming in a manner at once delighted and annoyed3 ,i love it1 but ,i owe it a grudge6 ,since he realized the interest in these physiological effects of radium1 ,pierre ,curie undertook1 in collaboration with physicians1 the investigations to which ,i have just referred1 submitting animals to the action of radium emanation4 ,these studies formed the point of departure in radium therapy4 ,the first attempts at treatment with radium were made with products loaned by ,pierre ,curie1 and had as their object the cure of lupus and other skin lesions4 ,thus radium therapy1 an important branch of medicine1 and frequently designated as ,curietherapie1 was born in ,france1 and was developed first through the investigations of ,french physicians 7,danlos1 ,oudin1 ,wickham1 ,dominici1 ,cheron1 ,degrais1 and others74#aa ,in the meantime the great impetus given to the study of radioactivity abroad led to a rapid succession of new discoveries4 ,many scientists engaged in the search for other radio elements1 using the new method of chemical analysis1 with the aid of radiation1 that we had inaugurated4 ,thus were found the mesothorium now used by physicians and manufactured industrially1 radio-thorium1 ionium1 protoactinium1 radio-lead1 and other substances4 ,at present we know1 in all1 about thirty radio elements 7among which three are gases1 or emanations71 but among them all radium still plays the most important part1 because of the great intensity of its radiation1 which diminishes only extremely slowly during the course of years4 ,the year #aijc was especially important in the development of the new science4 ,in this year the investigation of radium1 the new chemical element1 was achieved1 and ,pierre ,curie demonstrated the astonishing discharge of heat by this element1 which nevertheless remained unaltered in appearance4 ,in ,england1 ,ramsay and ,soddy announced a great discovery4 ,they proved that radium continually produces helium gas and under conditions that force one to believe in an atomic transformation4 ,if1 indeed1 radium salt heated to its melting point is confined for some time in a sealed glass tube1 entirely emptied of air1 one can1 in reheating it1 make it throw off a small quantity of helium1 easy to measure and to recognize from the character of its spectrum4 ,this fundamental experiment has received numerous confirmations4 ,it furnished us the first example of a transformation of atoms1 independent1 it is true1 of our will1 but at the same time it reduces to nothing the theory of the absolute fixity of the atomic edifice4 ,all these facts1 along with others formerly known1 were made the object of a synthesis of the highest value1 in a work by ,e4 ,rutherford and ,f4 ,soddy1 who proposed a theory of radioactive transformations1 to-day universally adopted4 ,according to this theory1 each radio element1 even when it appears unchanged1 is undergoing a spontaneous transformation1 and the more rapid the transformation1 the more intense is the radiation4#ab ,a radioactive atom can transform itself in two ways3 it can expel from itself an atom of helium1 which1 thrown off at an enormous speed and with a positive charge1 constitutes an ,alpha ray4 ,or1 instead1 it can detach from its structure a much smaller fragment1 one of those electrons to which we have become accustomed in modern physics1 and whose mass1 #ahjj times smaller than that of an atom of hydrogen when its speed is moderate1 grows excessively when its speed approaches that of light4 ,these electrons1 which carry a negative charge1 form the ,beta rays4 ,whatever the detached fragment1 the residual atom no longer resembles the primitive atom4 ,thus when the atom of radium has expelled an atom of helium1 the residue is an atom of gaseous emanation4 ,this residue changes in its turn1 and the process is not arrested until the attainment of a last residue which is stable and does not give off any radiation4 ,this stable matter is inactive matter4 ,thus the ,alpha and ,beta rays result from the fragmentation of atoms4 ,gamma-rays are a radiation analogous to light1 which accompanies the cataclysm of the atomic transformation4 ,they are very penetrating1 and are the ones most used in the therapeutic methods so far developed4#ac ,we can see in all this that radio elements form families1 in which each member derives from a preceding member by direct descent the primary elements being uranium and thorium4 ,we can in particular prove that radium is a descendant of uranium1 and that polonium is a descendant of radium4 ,since each radio element1 at the same time that it is formed by the mother substance1 destroys itself1 it cannot accumulate in the presence of this mother substance beyond a determined proportion1 which explains why the relation between radium and uranium remains constant in the very ancient unaltered minerals4 ,the spontaneous destruction of radio elements takes place according to a fundamental law1 called the exponential law1 according to which the quantity of each radio element diminishes by one-half in a time always the same1 called a period1 this time-period making it possible to determine without ambiguity the element under consideration4 ,these periods1 which can be measured by diverse methods1 vary greatly4 ,the period of uranium is several billions of years2 that of radium is about #afjj years2 that of its emanation a little less than four days2 and there are among the following descendants some whose period is the small fraction of a second4 ,the exponential law has a profound philosophic bearing2 it indicates that the transformation is produced according to the laws of probability4 ,the causes that determine the transformation are a mystery to us1 and we do not yet know if they derive from causal conditions outside the atom1 or from conditions of internal instability4 ,in many cases1 up to the present1 no exterior action has shown itself effective in influencing the transformation4 ,this rapid succession of discoveries which overthrew familiar scientific conceptions long held in physics and chemistry did not fail to meet1 at first1 with doubts and incredulity4 ,but the great part of the scientific world received them with enthusiasm4 ,at the same time ,pierre ,curie's fame grew in ,france and in foreign countries4 ,already in #aija the ,academy of ,sciences had awarded him the ,lacaze prize4 ,in #aijb1 ,mascart1 who had many times given him most valuable aid1 decided to propose him as a member of the ,academy of ,sciences4 ,it was not easy for ,pierre ,curie to agree to this1 believing1 as he did1 that the ,academy should elect its members without the necessity of any preliminary solicitation or paying of calls4 ,nevertheless1 because of the friendly insistence of ,mascart1 and above all because the ,physics ,section of the ,academy had already declared itself unanimously in his favor1 he presented himself4 ,in spite of this1 however1 he failed of election1 and it was only in #aije that he became a member of the ,institute1 a membership which did not last even a year4 ,he was also elected to several academies and scientific societies in other countries1 and given an honorary doctor's degree by several universities4 ,during #aijc we went to ,london at the invitation of the ,royal ,institution1 before which my husband was to lecture on radium4 ,on this occasion he had a most enthusiastic reception4 ,he was especially happy to see here again ,lord ,kelvin1 who had always expressed an affection for him1 and who1 despite his advanced age1 preserved an interest1 perennially young1 in science4 ,the illustrious scientist showed1 with touching satisfaction1 a glass vial containing a grain of radium salt that ,pierre ,curie had given him4 ,we met here also other celebrated scientists1 as ,crookes1 ,ramsay1 and ,j4 ,dewar4 ,in collaboration with the latter1 ,pierre ,curie published investigations on the discharge of heat by radium at very low temperatures1 and upon the formation of helium in radium salt4 ,a few months later the ,davy medal was conferred upon him 7and also upon me7 by the ,royal ,society of ,london1 and at almost the same time1 we received1 together with ,henri ,becquerel1 the ,nobel prize for physics4 ,our health prevented us from attending the ceremony for the awarding of this prize in ,december1 and it was only in ,june1 #aije1 that we were able to go to ,stockholm where ,pierre ,curie gave his ,nobel lecture4 ,we were most cordially received and had the felicity of seeing the admirable ,swedish nature in its most brilliant aspect4 ,the award of the ,nobel prize was an important event for us because of the prestige carried by the ,nobel foundation1 only recently founded 7#aija74 ,also1 from a financial point of view1 the half of the prize represented an important sum4 ,it meant that in the future ,pierre ,curie could turn over his teaching in the ,school of ,physics to ,paul ,langevin1 one of his former students1 and a physicist of great competence4 ,he could also engage a preparator to aid him in his work4 ,but at the same time the publicity this very happy event entailed bore very heavily on a man who was neither prepared for it1 nor accustomed to it4 ,there followed an avalanche of visits1 of letters1 of demands for articles and lectures1 which meant a constant enervation1 fatigue1 and loss of time4 ,he was kind and did not like to refuse a request2 but on the other hand1 he had to recognize that he could not accede to the solicitations that overwhelmed him without disastrous results to his health1 as well as to his peace of mind1 and his work4 ,in a letter to ,ch4 ,ed4 ,guillaume1 he said3 ,people ask me for articles and lectures1 and after a few years are passed1 the very persons who make these demands will be astonished to see that we have not accomplished any work4 ,and in other letters of the same period1 written to ,e4 ,gouy1 he expressed himself as follows3 #bj ,march #aijb ,as you have seen1 fortune favors us at this moment2 but these favors of fortune do not come without many worries4 ,we have never been less tranquil than at this moment4 ,there are days when we scarcely have time to breathe4 ,and to think that we dreamed of living in the wild1 quite removed from human beings6 #bb ,january #aijd ,,my ,,dear ,,friend3 ,i have wanted to write to you for a long time2 excuse me if ,i have not done so4 ,the cause is the stupid life which ,i lead at present4 ,you have seen this sudden infatuation for radium1 which has resulted for us in all the advantages of a moment of popularity4 ,we have been pursued by journalists and photographers from all countries of the world2 they have gone even so far as to report the conversation between my daughter and her nurse1 and to describe the black-and-white cat that lives with us4444 ,further1 we have had a great many appeals for money4444 ,finally1 the collectors of autographs1 snobs1 society people1 and even at times1 scientists1 have come to see us--in our magnificent and tranquil quarters in the laboratory--and every evening there has been a voluminous correspondence to send off4 ,with such a state of things ,i feel myself invaded by a kind of stupor4 ,and yet all this turmoil will not perhaps have been in vain1 if it results in my getting a chair and a laboratory4 ,to tell the truth1 it will be necessary to create the chair1 and ,i shall not have the laboratory at first4 ,i should have preferred the reverse1 but ,liard wishes to take advantage of the present moment to bring about the creation of a new chair that will later be acquired for the university4 ,they are to establish a chair without a fixed program1 which will be something like a course in the ,collge de ,france1 and ,i believe ,i shall be obliged to change my subject each year1 which will be a great trial to me4 #ca ,january #aije 444 ,i have had to give up going to ,sweden4 ,we are1 as you see1 most irregular in our relations with the ,swedish ,academy2 but1 to tell the truth1 ,i can only keep up by avoiding all physical fatigue4 ,and my wife is in the same condition2 we can no longer dream of the great work days of times gone by4 ,as to research1 ,i am doing nothing at present4 ,with my course1 my students1 apparatus to install1 and the interminable procession of people who come to disturb me without serious reason1 the days pass without my having been able to achieve anything useful at this end4 #be ,july #aije ,,my ,,dear ,,friend3 ,we have regretted so much being deprived of your visit this year1 but hope to see you in ,october4 ,if we do not make an effort from time to time1 we end by losing touch with our best and most congenial friends1 and in keeping company with others for the simple reason that it is easy to meet them4 ,we continue to lead the same life of people who are extremely occupied1 without being able to accomplish anything interesting4 ,it is now more than a year since ,i have been able to engage in any research1 and ,i have no moment to myself4 ,clearly ,i have not yet discovered a means to defend ourselves against this frittering away of our time which is nevertheless extremely necessary4 ,intellectually1 it is a question of life or death4 #g ,november #aije ,i begin my course tomorrow but under very bad conditions for the preparation of my experiments4 ,the lecture room is at the ,sorbonne1 and my laboratory is in the rue ,cuvier4 ,besides1 a great number of other courses are given in the same lecture room1 and ,i can use it only one morning for the preparation of my own4 ,i am neither very well1 nor very ill2 but ,i am easily fatigued1 and ,i have left but very little capacity for work4 ,my wife1 on the contrary1 leads a very active life1 between her children1 the ,school at ,svres1 and the laboratory4 ,she does not lose a minute1 and occupies herself more regularly than ,i can with the direction of the laboratory in which she passes the greater part of the day4 ,to sum up3 despite these outside complications1 our life1 by a common effort of will1 remained as simple and as retired as formerly4 ,toward the close of #aijd our family was increased by the birth of a second daughter4 ,eve ,denise was born in the modest house in ,boulevard ,kellermann1 where we still lived with ,doctor ,curie1 seeing only a few friends4 ,as our elder daughter grew up1 she began to be a little companion to her father1 who took a lively interest in her education and gladly went for walks with her in his free times1 especially on his vacation days4 ,he carried on serious conversations with her1 replying to all her questions and delighting in the progressive development of her young mind4 ,from their early age1 his children enjoyed his tender affection1 and he never wearied of trying to understand these little beings1 in order to be able to give them the best he had to give4 ,with his great success in other countries1 the complete appreciation of ,pierre ,curie in ,france1 however tardily1 did at last follow4 ,at forty-five he found himself in the first rank of ,french scientists and yet1 as a teacher1 he occupied an inferior position4 ,this abnormal state of affairs aroused public opinion in his favor1 and under the influence of this wave of feeling1 the director of the ,academy of ,paris1 ,l4 ,liard1 asked ,parliament to create a new professorship in the ,sorbonne1 and at the beginning of the academic year #aijd-je ,pierre ,curie was named titular professor of the ,faculty of ,sciences of ,paris4 ,a year later he definitely quitted the ,school of ,physics where his substitute1 ,paul ,langevin1 succeeded him4 ,this new professorship was not established without a few difficulties4 ,the first project had provided for a new chair1 but not for a laboratory4 ,and ,pierre ,curie felt that he could not accept a situation which involved the risk of losing even the mediocre means of work that he then had1 instead of offering better ones4 ,he wrote1 therefore1 to his chiefs1 that he had decided to remain at the ,p4,c4,n4 ,his firmness won the day4 ,to the new chair was added a fund for a laboratory and personnel for the new work 7a chief of laboratory1 a preparator1 and a laboratory boy74 ,the position of chief of laboratory was offered to me1 which was a cause of very great satisfaction to my husband4 ,it was not without regret that we left the ,school of ,physics1 where we had known such happy work days1 despite their attendant difficulties4 ,we had become particularly attached to our hangar1 which continued to stand1 though in a state of increasing decay1 for several years1 and we went to visit it from time to time4 ,later it had to be pulled down to make way for a new building for the ,physics ,school1 but we have preserved photographs of it4 ,warned of its approaching destruction by the faithful ,petit1 ,i made my last pilgrimage there1 alas1 alone4 ,on the blackboard there was still the writing of him who had been the soul of the place2 the humble refuge for his research was all impregnated with his memory4 ,the cruel reality seemed some bad dream2 ,i almost expected to see the tall figure appear1 and to hear the sound of the familiar voice4 ,even though ,parliament had voted the creation of a new chair1 it did not go so far as to consider the simultaneous founding of a laboratory which was1 nevertheless1 necessary to the development of the new science of radioactivity4 ,pierre ,curie therefore kept the little workroom at the ,p4,c4,n41 and secured as a temporary solution of his difficulty the use of a large room1 then not being used by the ,p4,c4,n4 ,he arranged1 too1 to have a little building consisting of two rooms and a study set up in the court4 ,one cannot help feeling sorrow in realizing that this was a last concession1 and that actually one of the first ,french scientists never had an adequate laboratory to work in1 and this even though his genius had revealed itself as early as his twentieth year4 ,without doubt if he had lived longer1 he would have had the benefit of satisfactory conditions for his work1 but he was still deprived of them at his death at the premature age of forty-eight4 ,can we fully imagine the regret of an enthusiastic and disinterested worker in a great work1 who is retarded in the realization of his dream by the constant lack of means8 ,and can we think without a feeling of profound grief of the waste--the one irreparable one--of the nation's greatest asset3 the genius1 the powers1 and the courage of its best children8 ,pierre ,curie had always in mind his urgent need for a good laboratory4 ,when1 because of his great reputation1 his chiefs felt obliged to try to induce him1 in #aijc1 to accept the decoration of the ,lgion d',honneur1 he declined that distinction1 remaining true to the opinion already referred to in a preceding chapter4 ,and the letter he wrote on this occasion was inspired by the same feeling as that in the one previously quoted1 when he wrote to his director to refuse the palmes acadmiques4 ,i quote an extract3 ,i pray you to thank the ,minister1 and to inform him that ,i do not in the least feel the need of a decoration1 but that ,i do feel the greatest need for a laboratory4 ,after he was named professor at the ,sorbonne1 ,pierre ,curie had to prepare a new course4 ,the position had been given a very personal character and a very general scope4 ,he was left great freedom in the choice of the matter he would present4 ,taking advantage of this freedom he returned to a subject that was dear to him1 and devoted part of his lectures to the laws of symmetry1 the study of fields of vectors and tensors1 and to the application of these ideas to the physics of crystals4 ,he intended to carry these lessons further1 and to work out a course that would completely cover the physics of crystallized matter which would have been especially useful because this subject was so little known in ,france4 ,his other lessons dealt with radioactivity1 set forth the discoveries made in this new domain1 and the revolution they had caused in science4 ,even though he was very much absorbed in the preparation of his course1 and often ill1 my husband continued1 nevertheless1 to work in the laboratory1 which was becoming better and better organized4 ,he had a little more space now1 and could receive a few students4 ,in collaboration with ,a4 ,laborde1 he carried on investigations in mineral waters and gases discharged from springs4 ,this was the last work he published4 ,his intellectual faculties were at this time at their height4 ,one could but admire the surety and rigor of his reasoning on the theories of physics1 his clear comprehension of fundamental principles1 and a certain profound sense of phenomena which he had by instinct1 but which he perfected during the course of a life entirely consecrated to research and reflection4 ,his skill in experiment1 remarkable from the beginning1 was increased by practice4 ,he experienced the pleasure of an artist when he succeeded with a delicate installation4 ,he enjoyed1 too1 devising and constructing new apparatus1 and ,i used jokingly to tell him that he would not be happy unless he made at least an attempt of this kind once every six months4 ,his natural curiosity and vivid imagination pushed him to undertakings in very varied directions2 he could change the object of his research with surprising ease4 ,he was scrupulously careful of scientific probity and of complete accuracy in his publications4 ,these are very perfect in form1 and none the less so in those parts where he applies the critical spirit to himself1 expressing his determination never to affirm anything that does not seem entirely clear4 ,he expresses his thought on this point in the following words3 ,in the study of unknown phenomena1 one can make very general hypotheses and then advance step by step with the help of experience4 ,this method of progress is sure but necessarily slow4 ,one can1 on the contrary1 make daring hypotheses in which he specifies the mechanism of phenomena4 ,such a method of procedure has the advantage of suggesting certain experiments1 and1 above all1 of facilitating reasoning by rendering it less abstract through the employment of an image4 ,but on the other hand1 one cannot hope thus to conceive a complex theory in accord with experiment4 ,the precise hypothesis almost certainly includes a portion of error along with a portion of truth4 ,and this last portion1 if it exists1 forms only a part of a more general proposition to which it will be necessary in the end to return4 ,moreover1 even though he never hesitated to make hypotheses1 he never permitted their premature publication4 ,he could never accustom himself to a system of work which involved hasty publications1 and was always happier in a domain in which but a few investigators were quietly working4 ,the considerable vogue of radioactivity made him wish to abandon this field of research for a time1 and to return to his interrupted studies of the physics of crystals4 ,he dreamed also of making an examination of diverse theoretical questions4 ,he gave much thought to his teaching1 which constantly improved1 and which suggested to him ideas on the general orientation of studies and on methods of teaching1 which he believed should be based on contact with experience and nature4 ,he hoped to see his views adopted by the ,association of ,professors as soon as it was formed1 and to obtain the declaration that the teaching of the sciences must be the dominant teaching of both the boys' and girls' lyces4 ,but1 he said1 such a notion would have little chance of success4 ,but this last period of his life1 so fecund1 was1 alas1 soon to end4 ,his admirable scientific career was to be suddenly broken at the very moment when he could hope that the years of work to come would be less hard than those which had preceded4 ,in #aijf1 quite ill and tired1 he went with me and the children to spend ,easter in the ,chevreuse ,valley4 ,those were two sweet days under a mild sun1 and ,pierre ,curie felt the weight of weariness lighten in a healing repose near to those who were dear to him4 ,he amused himself in the meadows with his little girls1 and talked with me of their present and their future4 ,he returned to ,paris for a reunion and dinner of the ,physics ,society4 ,there he sat beside ,henri ,poincar and had a long conversation with him on methods of teaching4 ,as we were returning on foot to our house1 he continued to develop his ideas on the culture that he dreamed of1 happy in the consciousness that ,i shared his views4 ,the following day1 the #aith of ,april1 #aijf1 he attended a reunion of the ,association of ,professors of the ,faculties of the ,sciences1 where he talked with them very cordially about the aims which the ,association might adopt4 ,as he went out from this reunion and was crossing the rue ,dauphine1 he was struck by a truck coming from the ,pont ,neuf1 and fell under its wheels4 ,a concussion of the brain brought instantaneous death4 ,so perished the hope founded on the wonderful being who thus ceased to he4 ,in the study room to which he was never to return1 the water buttercups he had brought from the country were still fresh4 ,footnote #i3 ,during my recent visit to ,america1 where a gramme of radium was generously offered me by ,american women1 the ,buffalo ,society of ,natural ,sciences presented me1 as a souvenir1 with a publication reviewing the development of the radium industry in the ,united ,states4 ,this included photographic reproductions of letters from ,pierre ,curie in which he replied in as complete a manner as possible to the questions asked by ,american engineers4 7#aijb and #aijc47 ,footnote #aj3 ,the price of a milligramme of the element of radium was then fixed at about #gej francs4 ,footnote #aa3 ,these physicians were aided by the manufacturer1 ,armet de ,lisle1 who placed at their disposition the radium needed for their first undertakings4 ,he founded1 besides1 in #aijf1 a laboratory for clinical study1 provided with a supply of radium4 ,and he subventioned the first special publication devoted to radioactivity and its applications1 as a journal under the name ,radium1 edited by ,j4 ,danne4 ,this is an example of generous support of science by industry1 in reality still very rare but which one wishes might become general1 in the common interest of these two branches of human activity4 ,footnote #ab3 ,the hypothesis according to which radioactivity is bound up with the atomic transformation of elements was first envisaged by ,pierre ,curie and by me1 along with other possible hypotheses1 before it was utilized by ,e4 ,rutherford4 7,see ,revue ,scientifique1 #aijj1 ,mme4 ,curie1 etc47 ,footnote #ac3 ,by using the unusual energy of ,alpha-rays ,e4 ,rutherford has obtained recently the rupture of certain light atoms1 like those of nitrogen4 ,,chapter ,,vii ,,the ,,nation',s ,,sorrow4 ,,the ,,laboratories3 ,,sacred ,,places ,i shall not attempt to describe the grief of the family left by ,pierre ,curie4 ,by what ,i have earlier said in this narrative one can understand what he meant to his father1 his brother1 and his wife4 ,he was1 too1 a devoted father1 tender in his love for his children1 and happy to occupy himself with them4 ,but our daughters were still too young at this time to realize the calamity that had befallen us4 ,their grandfather and ,i1 united in our common suffering1 did what we could to see that their childhood should not be too much darkened by the disaster4 ,the news of the catastrophe caused veritable consternation in the scientific world of ,france1 as well as in that of other countries4 ,the heads of the university and the professors expressed their emotion in letters full of sympathy1 and a great number of foreign scientists also sent letters and telegrams4 ,no less deep was the impression produced on the public with whom ,pierre ,curie1 despite his reserve1 enjoyed great renown4 ,this feeling was expressed in numerous private letters coming not only from those whom we knew1 but also from persons entirely unknown to us4 ,at the same time the press printed articles of regret1 bearing the stamp of deep sincerity4 ,the ,french government sent its condolences1 and a few rulers of foreign countries sent their personal expressions of sympathy4 ,one of the purest glories of ,france had been extinguished1 and each understood that this was a nation's sorrow4#ad ,faithful to the memory of him who had left us1 we wished a simple interment in the family vault in the little cemetery at ,sceaux4 ,there was neither official ceremony nor address1 and only his friends accompanied him to his last home4 ,as he thought of him who was no more1 his brother ,jacques said to me3 ,he had all the gifts2 there were not two like him4 ,in order to assure the continuance of his work1 the ,faculty of ,sciences of ,paris paid me the very great honor of asking me to take the place that he had occupied4 ,i accepted this heavy heritage1 in the hope that ,i might build up some day1 in his memory1 a laboratory worthy of him1 which he had never had1 but where others would be able to work to develop his idea4 ,this hope is now partly realized1 thanks to the common initiative of the ,university and the ,pasteur ,institute1 which have aimed at the creation of a ,radium ,institute1 composed of two laboratories1 the ,curie and the ,pasteur1 destined for the physicochemical and the biological study of radium rays4 ,in touching homage to him who had disappeared the new street leading to the ,institute was named rue ,pierre ,curie4 ,this ,institute is1 however1 insufficient in view of the considerable development of radioactivity and of its therapeutic applications4 ,the best authorized persons now recognize that ,france must possess a ,radium ,institute comparable to those of ,england and ,america for the ,curietherapie which has become an efficacious means in the battle against cancer4 ,it is to be hoped that with generous and far-seeing aid1 we shall have1 in a few years1 a ,radium ,institute complete and enlarged1 worthy of our country4 ,to honor the memory of ,pierre ,curie1 the ,french ,society of ,physics decided to issue a complete publication of his works4 ,this publication1 arranged by ,p4 ,langevin and ,c4 ,cheneveau1 comprises but a single volume of about #fjj pages1 which appeared in #aijh1 and for which ,i wrote a preface4 ,this unique volume1 which includes a work as important as it is varied1 is a faithful reflection of the mentality of the author4 ,one finds in it a great richness of ideas and of experimental facts leading to clear and well-established results1 but the exposition is limited to the strictly necessary1 and is irreproachable1 one might even say classical1 in form4 ,it is to be regretted that ,pierre ,curie did not use his gifts as scientist and author in writing extended memoirs or books4 ,it was not the desire that was lacking2 he had several cherished projects of this nature4 ,but he could never put them into execution because of the difficulties with which he had to struggle during all his working life4 ,and now1 let us glance at this narrative as a whole1 in which ,i have attempted to evoke the image of a man who1 inflexibly devoted to the service of his ideal1 honored humanity by an existence lived in silence1 in the simple grandeur of his genius and his character4 ,he had the faith of those who open new ways4 ,he knew that he had a high mission to fulfil and the mystic dream of his youth pushed him invincibly beyond the usual path of life into a way which he called anti-natural because it signified the renunciation of the pleasures of life4 ,nevertheless1 he resolutely subordinated his thoughts and desires to this dream1 adapting himself to it and identifying himself with it more and more completely4 ,believing only in the pacific might of science and of reason1 he lived for the search of truth4 ,without prejudice or parti pris1 he carried the same loyalty into his study of things that he used in his understanding of other men and of himself4 ,detached from every common passion1 seeking neither supremacy nor honors1 he had no enemies1 even though the effort he had achieved in the control of himself had made of him one of those elect whom we find in advance of their time in all the epochs of civilization4 ,like them he was able to exercise a profound influence merely by the radiation of his inner strength4 ,it is useful to learn how much sacrifice such a life represents4 ,the life of a great scientist in his laboratory is not1 as many may think1 a peaceful idyll4 ,more often it is a bitter battle with things1 with one's surroundings1 and above all with oneself4 ,a great discovery does not leap completely achieved from the brain of the scientist1 as ,minerva sprang1 all panoplied1 from the head of ,jupiter2 it is the fruit of accumulated preliminary work4 ,between the days of fecund productivity are inserted days of uncertainty when nothing seems to succeed1 and when even matter itself seems hostile2 and it is then that one must hold out against discouragement4 ,thus without ever forsaking his inexhaustible patience1 ,pierre ,curie used sometimes to say to me3 ,it is nevertheless hard1 this life that we have chosen4 ,for the admirable gift of himself1 and for the magnificent service he renders humanity1 what reward does our society offer the scientist8 ,have these servants of an idea the necessary means of work8 ,have they an assured existence1 sheltered from care8 ,the example of ,pierre ,curie1 and of others1 shows that they have none of these things2 and that more often1 before they can secure possible working conditions1 they have to exhaust their youth and their powers in daily anxieties4 ,our society1 in which reigns an eager desire for riches and luxury1 does not understand the value of science4 ,it does not realize that science is a most precious part of its moral patrimony4 ,nor does it take sufficient cognizance of the fact that science is at the base of all the progress that lightens the burden of life and lessens its suffering4 ,neither public powers nor private generosity actually accord to science and to scientists the support and the subsidies indispensable to fully effective work4 ,i invoke1 in closing1 the admirable pleading of ,pasteur3 ,if the conquests useful for humanity touch your heart1 if you are overwhelmed before the astonishing results of electric telegraphy1 of the daguerrotype1 of anesthesia1 and of other wonderful discoveries1 if you are jealous of the part your country may claim in the spreading of these marvelous things1 take an interest1 ,i beg of you1 in those sacred places to which we give the expressive name of laboratories4 ,demand that they be multiplied and ornamented1 for these are the temples of the future1 of wealth1 and of well-being4 ,it is in them that humanity grows1 fortifies itself1 and becomes better4 ,there it may learn to read in the works of nature the story of progress and of universal harmony1 even while its own creations are too often those of barbarism1 fanaticism1 and destruction4 ,may this truth be widely spread1 and deeply penetrate public opinion1 that the future may be less hard for the pioneers who must open up new domains for the general good of humanity4 ,extracts from ,published ,appreciations ,i have chosen certain extracts from various published appreciations of ,pierre ,curie in order to complete my account by a few moving testimonies from eminent men of science4 ,henri ,poincar3 ,curie was one of those on whom ,science and ,france believed they had the right to count4 ,his age permitted far-reaching hopes2 what he had already given seemed a promise1 and we knew that1 living1 he would not have failed4 ,on the night preceding his death 7pardon this personal memory7 ,i sat next to him and he talked with me of his plans and his ideas4 ,i admired the fecundity and the depth of his thought1 the new aspect which physical phenomena took on when looked at through that original and lucid mind4 ,i felt that ,i better understood the grandeur of human intelligence--and the following day1 in an instant1 all was annihilated4 ,a stupid accident brutally reminded us how little place thought holds in the face of the thousand blind forces that hurl themselves across the world without knowing whither they go1 crushing all in their passage4 ,his friends1 his colleagues understood at once the import of the loss they suffered1 but the grief extended far beyond them4 ,in foreign countries the most illustrious scientists joined in trying to show the esteem in which they held our compatriot1 while in our own land there was no ,frenchman1 however ignorant1 who did not feel more or less vaguely what a force his nation and humanity had lost4 ,curie brought to his study of physical phenomena ,i do not know what very fine sense which made him divine unsuspected analogies1 and made it possible for him to orient himself in a labyrinth of complex appearances where others would have gone astray4444 ,true physicists1 like ,curie1 neither look within themselves1 nor on the surface of things1 but they know how to look through things4 ,all those who knew him knew their pleasure and surety in his acquaintance1 and the delicate charm that was exhaled1 one might say1 by his gentle modesty1 by his nave directness1 by the fineness of his spirit4 ,always ready to efface himself before his family1 before his friends1 and even before his rivals1 he was what one calls a 'poor candidate'2 but in our democracy candidates are the least thing we lack4 ,who would have thought that so much gentleness concealed an intransigeant soul8 ,he did not compromise with those general principles on which he was nourished1 nor with the particular moral ideal he had been taught to love1 that ideal of absolute sincerity1 too high1 perhaps1 for the world in which we live4 ,he did not know the thousand little accommodations with which our weakness contents itself4 ,moreover1 he never separated the worship of this ideal from what he rendered to science1 and he gave us a shining example of the high conception of duty that may spring from a simple and pure love of truth4 ,it matters little in what ,god he believed2 it is not the ,god1 but faith1 that performs miracles4 ,institut de ,france3 ,written about ,p4 ,curie by ,m4 ,d4 ,gernez4 ,all for work1 all for science3 this sums up the life of ,pierre ,curie1 a life so rich in brilliant discoveries and in the outlook of genius that it won him practically universal admiration4 ,in the full maturity of his investigations whose progress he so eagerly pursued his work was ended1 to the consternation of us all1 by a terrible catastrophe on the #aith of ,april1 #aijf4444 ,all these honors did not dazzle him2 he was and he will remain a remarkable figure among those who make the scientific history of our epoch4 ,his contemporaries found in him a precious example of a devotion to science at once unyielding and disinterested4 ,there have been few lives more pure and more justly famous4 ,jean ,perrin3 ,pierre ,curie1 whom all called a master1 and whom we had the joy to call1 too1 our friend1 died suddenly in the fullness of his powers4444 ,we will try to show through him1 as an example1 what part a powerful genius can return to sincerity1 to liberty1 to the strong and calm audacity of thought which nothing can enchain and nothing can astonish4 ,we acknowledge also all the greatness of the soul where these fine qualities of intelligence and character were united in a most noble unselfishness and most exquisite goodness4 ,those who have known ,pierre ,curie1 know that1 near him one felt awaken the need to do and to understand4 ,we will try to honor his memory by spreading abroad this impression1 and we will ask his pale and beautiful face for the secret of that radiation which made all those who approached him better men4 ,c4 ,cheneveau3 444 ,in order to realize our irreparable loss we must remember ,curie's attachment to his students4444 ,some of us offered him1 with reason1 a veritable worship4444 ,for myself1 he was1 next to my own family1 one of those ,i loved most4 ,how well he knew how to surround his simple collaborator with a great and tender affection4 ,his immense kindness extended even to his most humble helpers1 who adored him4 ,i have never seen more sincere and more heart-breaking tears than those shed by the laboratory boys on the news of his sudden death4 ,paul ,langevin3 444 ,the hours when one could meet him and in which one loved to talk about his science and in which one thought with him1 return each day to recall his memory1 to bring back his kindly and thoughtful face1 his luminous eyes and his beautiful1 expressive head modeled by twenty-five years passed in the laboratory1 and by a life of unremittent work and complete simplicity4 444 ,it is in his laboratory that my memories1 still so recent1 most readily bring him back to me1 as he would appear to those near to whom he had grown older1 scarcely changed by the eighteen years that have passed since4 ,timid and often awkward1 ,i began under him my laboratory education4444 ,surrounded by apparatus for the greater part conceived or modified by himself1 he manipulated it with extreme dexterity1 with the familiar gestures of the long white hands of the physicist4444 ,he was twenty-nine years old when ,i entered as a student4 ,the mastery which ten years1 passed entirely in the laboratory1 had given him1 imposed itself even on us1 despite our ignorance1 by the surety of his movements and explanations1 and the ease1 shaded by timidity1 of his manner4 ,we returned always with joy to the laboratory1 where it was good to work near him because we felt him working near to us in that large1 light room filled with apparatus whose forms were still a little mysterious to us4 ,we did not fear to enter it often to consult him1 and he sometimes admitted us1 too1 to perform some particularly delicate manipulation4 ,probably my finest memories of my school years are those of moments passed there standing before the blackboard where he took pleasure in talking with us1 in awakening in us fruitful ideas1 and in discussions of research which formed our taste for the things of science4 ,his live and contagious curiosity1 the fullness and surety of his information made him an admirable awakener of spirits4 ,i have wished above all1 in gathering together here these few memories1 in a bouquet reverently placed upon his tomb1 to help1 if ,i can1 to fix the image of a man truly great in character and in thought1 of a wonderful representative of the genius of our race4 ,entirely unfranchised from ancient servitudes1 and passionately loving reason and clarity1 he was an example--as is a prophet inspired by truths of the future--of what may be realized in moral beauty and goodness by a free and upright spirit1 of constant courage1 and of a mental honesty which made him repulse what he did not understand1 and place his life in accord with this dream4 ,footnote #ad3 ,from the great number of letters and telegrams of condolence1 ,i quote1 as examples1 these lines written by three great scientists1 today no longer living4 ,from ,m4 ,berthelot3 ,,madame3 ,i do not wish to wait longer without sending you the sympathetic expression of my profound grief and of that of ,french and foreign scientists on the occasion of the common loss with you that we have all experienced4 ,we were struck as by lightning by the tragic news6 ,so many services already rendered science and humanity1 so many services that we awaited from that genial inventor3 all this vanished in an instant1 or become already but a memory6 ,from ,g4 ,lippmann3 ,,madame3 ,it is while traveling1 and very late1 that ,i receive the terrible news4 ,i feel as if ,i had lost a brother2 ,i did not know by what close ties ,i was attached to your husband4 ,i know today4 ,i suffer also for you1 ,madame4 ,believe in my sincere and respectful devotion4 ,from ,lord ,kelvin3 ,grievously distressed by terrible news of ,curie's death4 ,when will be funeral4 ,we arrive ,hotel ,mirabeau tomorrow morning4 ,kelvin1 ,villa ,st4 ,martin1 ,cannes4 ,,autobiographical ,,notes ,,marie ,,curie ,,chapter ,i ,i have been asked by my ,american friends to write the story of my life4 ,at first1 the idea seemed alien to me1 but ,i yielded to persuasion4 ,however1 ,i could not conceive my biography as a complete expression of personal feelings or a detailed description of all incidents ,i would remember4 ,many of our feelings change with the years1 and1 when faded away1 may seem altogether strange2 incidents lose their momentary interest and may be remembered as if they have occurred to some other person4 ,but there may be in a life some general direction1 some continuous thread1 due to a few dominant ideas and a few strong feelings1 that explain the life and are characteristic of a human personality4 ,of my life1 which has not been easy on the whole1 ,i have described the general course and the essential features1 and ,i trust that my story gives an understanding of the state of mind in which ,i have lived and worked4 ,my family is of ,polish origin1 and my name is ,marie ,sklodowska4 ,my father and my mother both came from among the small ,polish landed proprietors4 ,in my country this class is composed of a large number of families1 owners of small and medium-sized estates1 frequently interrelated4 ,it has been1 until recently1 chiefly from this group that ,poland has drawn her intellectual recruits4 ,while my paternal grandfather had divided his time between agriculture and directing a provincial college1 my father1 more strongly drawn to study1 followed the course of the ,university of ,petrograd1 and later definitely established himself at ,warsaw as ,professor of ,physics and ,mathematics in one of the lyceums of that city4 ,he married a young woman whose mode of life was congenial to his2 for1 although very young1 she had1 what was1 for that time1 a very serious education1 and was the director of one of the best ,warsaw schools for young girls4 ,my father and mother worshiped their profession in the highest degree and have left1 all over their country1 a lasting remembrance with their pupils4 ,i cannot1 even to-day1 go into ,polish society without meeting persons who have tender memories of my parents4 ,although my parents adopted a university career1 they continued to keep in close touch with their numerous family in the country4 ,it was with their relatives that ,i frequently spent my vacation1 living in all freedom and finding opportunities to know the field life by which ,i was deeply attracted4 ,to these conditions1 so different from the usual villegiature1 ,i believe1 ,i owe my love for the country and nature4 ,born at ,warsaw1 on the #gth of ,november1 #ahfg1 ,i was the last of five children1 but my oldest sister died at the early age of fourteen1 and we were left1 three sisters and a brother4 ,cruelly struck by the loss of her daughter and worn away by a grave illness1 my mother died at forty-two1 leaving her husband in the deepest sorrow with his children4 ,i was then only nine years old1 and my eldest brother was hardly thirteen4 ,this catastrophe was the first great sorrow of my life and threw me into a profound depression4 ,my mother had an exceptional personality4 ,with all her intellectuality she had a big heart and a very high sense of duty4 ,and1 though possessing infinite indulgence and good nature1 she still held in the family a remarkable moral authority4 ,she had an ardent piety 7my parents were both ,catholics71 but she was never intolerant2 differences in religious belief did not trouble her2 she was equally kind to any one not sharing her opinions4 ,her influence over me was extraordinary1 for in me the natural love of the little girl for her mother was united with a passionate admiration4 ,very much affected by the death of my mother1 my father devoted himself entirely to his work and to the care of our education4 ,his professional obligations were heavy and left him little leisure time4 ,for many years we all felt weighing on us the loss of the one who had been the soul of the house4 ,we all started our studies very young4 ,i was only six years old1 and1 because ,i was the youngest and smallest in the class1 was frequently brought forward to recite when there were visitors4 ,this was a great trial to me1 because of my timidity2 ,i wanted always to run away and hide4 ,my father1 an excellent educator1 was interested in our work and knew how to direct it1 but the conditions of our education were difficult4 ,we began our studies in private schools and finished them in those of the government4 ,warsaw was then under ,russian domination1 and one of the worst aspects of this control was the oppression exerted on the school and the child4 ,the private schools directed by ,poles were closely watched by the police and overburdened with the necessity of teaching the ,russian language even to children so young that they could scarcely speak their native ,polish4 ,nevertheless1 since the teachers were nearly all of ,polish nationality1 they endeavored in every possible way to mitigate the difficulties resulting from the national persecution4 ,these schools1 however1 could not legally give diplomas1 which were obtainable only in those of the government4 ,the latter1 entirely ,russian1 were directly opposed to the ,polish national spirit4 ,all instruction was given in ,russian1 by ,russian professors1 who1 being hostile to the ,polish nation1 treated their pupils as enemies4 ,men of moral and intellectual distinction could scarcely agree to teach in schools where an alien attitude was forced upon them4 ,so what the pupils were taught was of questionable value1 and the moral atmosphere was altogether unbearable4 ,constantly held in suspicion and spied upon1 the children knew that a single conversation in ,polish1 or an imprudent word1 might seriously harm1 not only themselves1 but also their families4 ,amidst these hostilities1 they lost all the joy of life1 and precocious feelings of distrust and indignation weighed upon their childhood4 ,on the other side1 this abnormal situation resulted in exciting the patriotic feeling of ,polish youths to the highest degree4 ,yet of this period of my early youth1 darkened though it was by mourning and the sorrow of oppression1 ,i still keep more than one pleasant remembrance4 ,in our quiet but occupied life1 reunions of relatives and friends of our family brought some joy4 ,my father was very interested in literature and well acquainted with ,polish and foreign poetry2 he even composed poetry himself and was able to translate it from foreign languages into ,polish in a very successful way4 ,his little poems on family events were our delight4 ,on ,saturday evenings he used to recite or read to us the masterpieces of ,polish prose and poetry4 ,these evenings were for us a great pleasure and a source of renewed patriotic feelings4 ,since my childhood ,i have had a strong taste for poetry1 and ,i willingly learned by heart long passages from our great poets1 the favorite ones being ,mickiewecz1 ,krasinski and ,slowacki4 ,this taste was even more developed when ,i became acquainted with foreign literatures2 my early studies included the knowledge of ,french1 ,german1 and ,russian1 and ,i soon became familiar with the fine works written in these languages4 ,later ,i felt the need of knowing ,english and succeeded in acquiring the knowledge of that language and its literature4 ,my musical studies have been very scarce4 ,my mother was a musician and had a beautiful voice4 ,she wanted us to have musical training4 ,after her death1 having no more encouragement from her1 ,i soon abandoned this effort1 which ,i often regretted afterwards4 ,i learned easily mathematics and physics1 as far as these sciences were taken in consideration in the school4 ,i found in this ready help from my father1 who loved science and had to teach it himself4 ,he enjoyed any explanation he could give us about ,nature and her ways4 ,unhappily1 he had no laboratory and could not perform experiments4 ,the periods of vacations were particularly comforting1 when1 escaping the strict watch of the police in the city1 we took refuge with relatives or friends in the country4 ,there we found the free life of the old-fashioned family estate2 races in the woods and joyous participation in work in the far-stretching1 level grain-fields4 ,at other times we passed the border of our ,russian-ruled division 7,congress ,poland7 and went southwards into the mountain country of ,galicia1 where the ,austrian political control was less oppressive than that which we suffered4 ,there we could speak ,polish in all freedom and sing patriotic songs without going to prison4 ,my first impression of the mountains was very vivid1 because ,i had been brought up in the plains4 ,so ,i enjoyed immensely our life in the ,carpathian villages1 the view of the pikes1 the excursions to the valleys and to the high mountain lakes with picturesque names such as3 ,the ,eye of the ,sea4 ,however1 ,i never lost my attachment to the open horizon and the gentle views of a plain hill country4 ,later ,i had the opportunity to spend a vacation with my father far more south in ,podolia1 and to have the first view of the sea at ,odessa1 and afterwards at the ,baltic shore4 ,this was a thrilling experience4 ,but it was in ,france that ,i become acquainted with the big waves of the ocean and the ever-changing tide4 ,all my life through1 the new sights of ,nature made me rejoice like a child4 ,thus passed the period of our school life4 ,we all had much facility for intellectual work4 ,my brother1 ,doctor ,sklodowski1 having finished his medical studies1 became later the chief physician in one of the principal ,warsaw hospitals4 ,my sisters and ,i intended to take up teaching as our parents had done4 ,however1 my elder sister1 when grown up1 changed her mind and decided to study medicine4 ,she took the degree of doctor at the ,paris ,university1 married ,doctor ,dluski1 a ,polish physician1 and together they established an important sanatorium in a wonderfully beautiful ,carpathian mountain place of ,austrian ,poland4 ,my second sister1 married in ,warsaw1 ,mrs4 ,szalay1 was for many years a teacher in the schools1 where she rendered great service4 ,later she was appointed in one of the lyceums of free ,poland4 ,i was but fifteen when ,i finished my high-school studies1 always having held first rank in my class4 ,the fatigue of growth and study compelled me to take almost a year's rest in the country4 ,i then returned to my father in ,warsaw1 hoping to teach in the free schools4 ,but family circumstances obliged me to change my decision4 ,my father1 now aged and tired1 needed rest2 his fortune was very modest4 ,so ,i resolved to accept a position as governess for several children4 ,thus1 when scarcely seventeen1 ,i left my father's house to begin an independent life4 ,that going away remains one of the most vivid memories of my youth4 ,my heart was heavy as ,i climbed into the railway car4 ,it was to carry me for several hours1 away from those ,i loved4 ,and after the railway journey ,i must drive for five hours longer4 ,what experience was awaiting me8 ,so ,i questioned as ,i sat close to the car window looking out across the wide plains4 ,the father of the family to which ,i went was an agriculturist4 ,his oldest daughter was about my age1 and although working with me1 was my companion rather than my pupil4 ,there were two younger children1 a boy and a girl4 ,my relations with my pupils were friendly2 after our lessons we went together for daily walks4 ,loving the country1 ,i did not feel lonesome1 and although this particular country was not especially picturesque1 ,i was satisfied with it in all seasons4 ,i took the greatest interest in the agricultural development of the estate where the methods were considered as models for the region4 ,i knew the progressive details of the work1 the distribution of crops in the fields2 ,i eagerly followed the growth of the plants1 and in the stables of the farm ,i knew the horses4 ,in winter the vast plains1 covered with snow1 were not lacking in charm1 and we went for long sleigh rides4 ,sometimes we could hardly see the road4 ,look out for the ditch6 ,i would call to the driver4 ,you are going straight into it1 and ,never fear6 he would answer1 as over we went6 ,but these tumbles only added to the gayety of our excursions4 ,i remember the marvelous snow house we made one winter when the snow was very high in the fields2 we could sit in it and look out across the rose-tinted snow plains4 ,we also used to skate on the ice of the river and to watch the weather anxiously1 to make sure that the ice was not going to give way1 depriving us of our pleasure4 ,since my duties with my pupils did not take up all my time1 ,i organized a small class for the children of the village who could not be educated under the ,russian government4 ,in this the oldest daughter of the house aided me4 ,we taught the little children and the girls who wished to come how to read and write1 and we put in circulation ,polish books which were appreciated1 too1 by the parents4 ,even this innocent work presented danger1 as all initiative of this kind was forbidden by the government and might bring imprisonment or deportation to ,siberia4 ,my evenings ,i generally devoted to study4 ,i had heard that a few women had succeeded in following certain courses in ,petrograd or in foreign countries1 and ,i was determined to prepare myself by preliminary work to follow their example4 ,i had not yet decided what path ,i would choose4 ,i was as much interested in literature and sociology as in science4 ,however1 during these years of isolated work1 trying little by little to find my real preferences1 ,i finally turned towards mathematics and physics1 and resolutely undertook a serious preparation for future work4 ,this work ,i proposed doing in ,paris1 and ,i hoped to save enough money to be able to live and work in that city for some time4 ,my solitary study was beset with difficulties4 ,the scientific education ,i had received at the lyceum was very incomplete2 it was well under the bachelorship program of a ,french lyceum2 ,i tried to add to it in my own way1 with the help of books picked up at random4 ,this method could not be greatly productive1 yet it was not without results4 ,i acquired the habit of independent work1 and learned a few things which were to be of use later on4 ,i had to modify my plans for the future when my eldest sister decided to go to ,paris to study medicine4 ,we had promised each other mutual aid1 but our means did not permit of our leaving together4 ,so ,i kept my position for three and a half years1 and1 having finished my work with my pupils1 ,i returned to ,warsaw1 where a position1 similar to the one ,i had left1 was awaiting me4 ,i kept this new place for only a year and then went back to my father1 who had retired some time before and was living alone4 ,together we passed an excellent year1 he occupying himself with some literary work1 while ,i increased our funds by giving private lessons4 ,meantime ,i continued my efforts to educate myself4 ,this was no easy task under the ,russian government of ,warsaw2 yet ,i found more opportunities than in the country4 ,to my great joy1 ,i was able1 for the first time in my life1 to find access to a laboratory3 a small municipal physical laboratory directed by one of my cousins4 ,i found little time to work there1 except in the evenings and on ,sundays1 and was generally left to myself4 ,i tried out various experiments described in treatises on physics and chemistry1 and the results were sometimes unexpected4 ,at times ,i would be encouraged by a little unhoped-for success1 at others ,i would be in the deepest despair because of accidents and failures resulting from my inexperience4 ,but on the whole1 though ,i was taught that the way of progress is neither swift nor easy1 this first trial confirmed in me the taste for experimental research in the fields of physics and chemistry4 ,other means of instruction came to me through my being one of an enthusiastic group of young men and women of ,warsaw1 who united in a common desire to study1 and whose activities were at the same time social and patriotic4 ,it was one of those groups of ,polish youths who believed that the hope of their country lay in a great effort to develop the intellectual and moral strength of the nation1 and that such an effort would lead to a better national situation4 ,the nearest purpose was to work at one's own instruction and to provide means of instruction for workmen and peasants4 ,in accordance with this program we agreed among ourselves to give evening courses1 each one teaching what he knew best4 ,there is no need to say that this was a secret organization1 which made everything extremely difficult4 ,there were in our group very devoted young people who1 as ,i still believe today1 could do truly useful work4 ,i have a bright remembrance of the sympathetic intellectual and social companionship which ,i enjoyed at that time4 ,truly the means of action were poor and the results obtained could not be considerable2 yet ,i still believe that the ideas which inspired us then are the only way to real social progress4 ,you cannot hope to build a better world without improving the individuals4 ,to that end each of us must work for his own improvement1 and at the same time share a general responsibility for all humanity1 our particular duty being to aid those to whom we think we can be most useful4 ,all the experiences of this period intensified my longing for further study4 ,and1 in his affection for me1 my father1 in spite of limited resources1 helped me to hasten the execution of my early project4 ,my sister had just married at ,paris1 and it was decided that ,i should go there to live with her4 ,my father and ,i hoped that1 once my studies were finished1 we would again live happily together4 ,fate was to decide otherwise1 since my marriage was to hold me in ,france4 ,my father1 who in his own youth had wished to do scientific work1 was consoled in our separation by the progressive success of my work4 ,i keep a tender memory of his kindness and disinterestedness4 ,he lived with the family of my married brother1 and1 like an excellent grandfather1 brought up the children4 ,we had the sorrow of losing him in #aijb1 when he had just passed seventy4 ,so it was in ,november1 #ahia1 at the age of twenty-four1 that ,i was able to realize the dream that had been always present in my mind for several years4 ,when ,i arrived in ,paris ,i was affectionately welcomed by my sister and brother-in-law1 but ,i stayed with them only for a few months1 for they lived in one of the outside quarters of ,paris where my brother-in-law was beginning a medical practice1 and ,i needed to get nearer to the schools4 ,i was finally installed1 like many other students of my country1 in a modest little room for which ,i gathered some furniture4 ,i kept to this way of living during the four years of my student life4 ,it would be impossible to tell of all the good these years brought to me4 ,undistracted by any outside occupation1 ,i was entirely absorbed in the joy of learning and understanding4 ,yet1 all the while1 my living conditions were far from easy1 my own funds being small and my family not having the means to aid me as they would have liked to do4 ,however1 my situation was not exceptional2 it was the familiar experience of many of the ,polish students whom ,i knew4 ,the room ,i lived in was in a garret1 very cold in winter1 for it was insufficiently heated by a small stove which often lacked coal4 ,during a particularly rigorous winter1 it was not unusual for the water to freeze in the basin in the night2 to be able to sleep ,i was obliged to pile all my clothes on the bedcovers4 ,in the same room ,i prepared my meals with the aid of an alcohol lamp and a few kitchen utensils4 ,these meals were often reduced to bread with a cup of chocolate1 eggs or fruit4 ,i had no help in housekeeping and ,i myself carried the little coal ,i used up the six flights4 ,this life1 painful from certain points of view1 had1 for all that1 a real charm for me4 ,it gave me a very precious sense of liberty and independence4 ,unknown in ,paris1 ,i was lost in the great city1 but the feeling of living there alone1 taking care of myself without any aid1 did not at all depress me4 ,if sometimes ,i felt lonesome1 my usual state of mind was one of calm and great moral satisfaction4 ,all my mind was centered on my studies1 which1 especially at the beginning1 were difficult4 ,in fact1 ,i was insufficiently prepared to follow the physical science course at the ,sorbonne1 for1 despite all my efforts1 ,i had not succeeded in acquiring in ,poland a preparation as complete as that of the ,french students following the same course4 ,so ,i was obliged to supply this deficiency1 especially in mathematics4 ,i divided my time between courses1 experimental work1 and study in the library4 ,in the evening ,i worked in my room1 sometimes very late into the night4 ,all that ,i saw and learned that was new delighted me4 ,it was like a new world opened to me1 the world of science1 which ,i was at last permitted to know in all liberty4 ,i have pleasant memories of my relations with my student companions4 ,reserved and shy at the beginning1 it was not long before ,i noticed that the students1 nearly all of whom worked seriously1 were disposed to be friendly4 ,our conversations about our studies deepened our interest in the problems we discussed4 ,among the ,polish students ,i did not have any companions in my studies4 ,nevertheless1 my relations with their small colony had a certain intimacy4 ,from time to time we would gather in one another's bare rooms1 where we could talk over national questions and feel less isolated4 ,we would also go for walks together1 or attend public reunions1 for we were all interested in politics4 ,by the end of the first year1 however1 ,i was forced to give up these relationships1 for ,i found that all my energy had to be concentrated on my studies1 in order to achieve them as soon as possible4 ,i was even obliged to devote most of my vacation time to mathematics4 ,my persistent efforts were not in vain4 ,i was able to make up for the deficiency of my training and to pass examinations at the same time with the other students4 ,i even had the satisfaction of graduating in first rank as licencie es sciences physiques in #ahic1 and in second rank as licencie es sciences mathmatiques in #ahid4 ,my brother-in-law1 recalling later these years of work under the conditions ,i have just described1 jokingly referred to them as the heroic period of my sister-in-law's life4 ,for myself1 ,i shall always consider one of the best memories of my life that period of solitary years exclusively devoted to the studies1 finally within my reach1 for which ,i had waited so long4 ,it was in #ahid that ,i first met ,pierre ,curie4 ,one of my compatriots1 a professor at the ,university of ,fribourg1 having called upon me1 invited me to his home1 with a young physicist of ,paris1 whom he knew and esteemed highly4 ,upon entering the room ,i perceived1 standing framed by the ,french window opening on the balcony1 a tall young man with auburn hair and large1 limpid eyes4 ,i noticed the grave and gentle expression of his face1 as well as a certain abandon in his attitude1 suggesting the dreamer absorbed in his reflections4 ,he showed me a simple cordiality and seemed to me very sympathetic4 ,after that first interview he expressed the desire to see me again and to continue our conversation of that evening on scientific and social subjects in which he and ,i were both interested1 and on which we seemed to have similar opinions4 ,some time later1 he came to me in my student room and we became good friends4 ,he described to me his days1 filled with work1 and his dream of an existence entirely devoted to science4 ,he was not long in asking me to share that existence1 but ,i could not decide at once2 ,i hesitated before a decision that meant abandoning my country and my family4 ,i went back to ,poland for my vacation1 without knowing whether or not ,i was to return to ,paris4 ,but circumstances permitted me again to take up my work there in the autumn of that year4 ,i entered one of the physics laboratories at the ,sorbonne1 to begin experimental research in preparation for my doctor's thesis4 ,again ,i saw ,pierre ,curie4 ,our work drew us closer and closer1 until we were both convinced that neither of us could find a better life companion4 ,so our marriage was decided upon and took place a little later1 in ,july1 #ahie4 ,pierre ,curie had just received his doctor's degree and had been made professor in the ,school of ,physics and ,chemistry of the ,city of ,paris4 ,he was thirty-six years old1 and already a physicist known and appreciated in ,france and abroad4 ,solely preoccupied with scientific investigation1 he had paid little attention to his career1 and his material resources were very modest4 ,he lived at ,sceaux1 in the suburbs of ,paris1 with his old parents1 whom he loved tenderly1 and whom he described as exquisite the first time he spoke to me about them4 ,in fact1 they were so3 the father was an elderly physician of high intellect and strong character1 and the mother the most excellent of women1 entirely devoted to her husband and her sons4 ,pierre's elder brother1 who was then professor at the ,university of ,montpellier1 was always his best friend4 ,so ,i had the privilege of entering into a family worthy of affection and esteem1 and where ,i found the warmest welcome4 ,we were married in the simplest way4 ,i wore no unusual dress on my marriage day1 and only a few friends were present at the ceremony1 but ,i had the joy of having my father and my second sister come from ,poland4 ,we did not care for more than a quiet place in which to live and to work1 and were happy to find a little apartment of three rooms with a beautiful view of a garden4 ,a few pieces of furniture came to us from our parents4 ,with a money gift from a relative we acquired two bicycles to take us out into the country4 ,,chapter ,,ii ,with my marriage there began for me a new existence entirely different from the solitary life that ,i had known during the preceding years4 ,my husband and ,i were so closely united by our affection and our common work that we passed nearly all of our time together4 ,i have only a few letters from him1 for we were so little apart4 ,my husband spent all the time he could spare from his teaching at his research work in the laboratory of the school in which he was professor and ,i obtained authorization to work with him4 ,our living apartment was near the school1 so we lost little time in going and coming4 ,as our material resources were limited1 ,i was obliged to attend to most of the housekeeping myself1 particularly the preparation of meals4 ,it was not easy to reconcile these household duties with my scientific work1 yet1 with good will1 ,i managed it4 ,the great thing was that we were alone together in the little home which gave us a peace and intimacy that were very enjoyable for us4 ,at the same time that ,i was working in the laboratory1 ,i still had to take a few study courses1 for ,i had decided to take part in the examination for a certificate that would allow me to teach young girls4 ,if ,i succeeded in this1 ,i would be entitled to be named professor4 ,in ,august1 #ahif1 after having devoted several months to preparation1 ,i came out first in the examination4 ,our principal distraction from the close work of the laboratory consisted in walks or bicycle rides in the country4 ,my husband greatly enjoyed the out-of-doors and took great interest in the plants and animals of woods and meadows4 ,hardly a corner in the vicinity of ,paris was unknown to him4 ,i also loved the country and these excursions were a great joy for me as well as to him1 relieving our mind from the tension of the scientific work4 ,we used to bring home bunches of flowers4 ,sometimes we forgot all about the time and got back late at night4 ,we visited regularly my husband's parents where our room was always ready4 ,in the vacation we went on longer outings by means of our bicycles4 ,in this way we covered much ground in ,auvergne and in the ,cevennes and visited several regions at the seashore4 ,we took a great delight in these long all-day excursions1 arriving at night always in a new place4 ,if we stayed in one place too long1 my husband began to wish to get back to the laboratory4 ,it is also in vacation time that we visited once my family in the ,carpathian mountains4 ,my husband learned some ,polish in view of this journey to ,poland4 ,but first of all in our life was our scientific work4 ,my husband gave much care to the preparation of his courses1 and ,i gave him some assistance in this1 which1 at the time1 helped me in my education4 ,however1 most of our time was devoted to our laboratory researches4 ,my husband did not then have a private laboratory4 ,he could1 to some extent1 use the laboratory of the school for his own work1 but found more freedom by installing himself in some unused corner of the ,physics ,school building4 ,i thus learned from his example that one could work happily even in very insufficient quarters4 ,at this time my husband was occupied with researches on crystals1 while ,i undertook an investigation of the magnetic properties of steel4 ,this work was completed and published in #ahig4 ,in that same year the birth of our first daughter brought a great change in our life4 ,a few weeks later my husband's mother died and his father came to live with us4 ,we took a small house with a garden at the border of ,paris and continued to occupy this house as long as my husband lived4 ,it became a serious problem how to take care of our little ,irene and of our home without giving up my scientific work4 ,such a renunciation would have been very painful to me1 and my husband would not even think of it2 he used to say that he had got a wife made expressly for him to share all his preoccupations4 ,neither of us would contemplate abandoning what was so precious to both4 ,of course we had to have a servant1 but ,i personally saw to all the details of the child's care4 ,while ,i was in the laboratory1 she was in the care of her grandfather1 who loved her tenderly and whose own life was made brighter by her4 ,so the close union of our family enabled me to meet my obligations4 ,things were particularly difficult only in case of more exceptional events1 such as a child's illness1 when sleepless nights interrupted the normal course of life4 ,it can be easily understood that there was no place in our life for worldly relations4 ,we saw but a few friends1 scientific workers1 like ourselves1 with whom we talked in our home or in our garden1 while ,i did some sewing for my little girl4 ,we also maintained affectionate relations with my husband's brother and his family4 ,but ,i was separated from all my relatives1 as my sister had left ,paris with her husband to live in ,poland4 ,it was under this mode of quiet living1 organized according to our desires1 that we achieved the great work of our lives1 work begun about the end of #ahig and lasting for many years4 ,i had decided on a theme for my doctorate4 ,my attention had been drawn to the interesting experiments of ,henri ,becquerel on the salts of the rare metal uranium4 ,becquerel had shown that by placing some uranium salt on a photographic plate1 covered with black paper1 the plate would be affected as if light had fallen on it4 ,the effect is produced by special rays which are emitted by the uranium salt and are different from ordinary luminous rays as they can pass through black paper4 ,becquerel also showed that these rays can discharge an electroscope4 ,he at first thought that the uranium rays were produced as a result of exposing the uranium salt to light1 but experiment showed that salts kept for several months in the dark continued the peculiar rays4 ,my husband and ,i were much excited by this new phenomenon1 and ,i resolved to undertake the special study of it4 ,it seemed to me that the first thing to do was to measure the phenomenon with precision4 ,in this ,i decided to use that property of the rays which enabled them to discharge an electroscope4 ,however1 instead of the usual electroscope1 ,i used a more perfect apparatus4 ,one of the models of the apparatus used by me for these first measurements is now in the ,college of ,physicians and ,surgeons in ,philadelphia4 ,i was not long in obtaining interesting results4 ,my determinations showed that the emission of the rays is an atomic property of the uranium1 whatever the physical or chemical conditions of the salt were4 ,any substance containing uranium is as much more active in emitting rays1 as it contains more of this element4 ,i then thought to find out if there were other substances possessing this remarkable property of uranium1 and soon found that substances containing thorium behaved in a similar way1 and that this behavior depended similarly on an atomic property of thorium4 ,i was now about to undertake a detailed study of the uranium and thorium rays when ,i discovered a new interesting fact4 ,i had occasion to examine a certain number of minerals4 ,a few of them showed activity2 they were those containing either uranium or thorium4 ,the activity of these minerals would have had nothing astonishing about it1 if it had been in proportion to the quantities of uranium or thorium contained in them4 ,but it was not so4 ,some of these minerals revealed an activity three or four times greater than that of uranium4 ,i verified this surprising fact carefully1 and could not doubt its truth4 ,speculating about the reason for this1 there seemed to be but one explanation4 ,there must be1 ,i thought1 some unknown substance1 very active1 in these minerals4 ,my husband agreed with me and ,i urged that we search at once for this hypothetical substance1 thinking that1 with joined efforts1 a result would be quickly obtained4 ,neither of us could foresee that in beginning this work we were to enter the path of a new science which we should follow for all our future4 ,of course1 ,i did not expect1 even at the beginning1 to find a new element in any large quantity1 as the minerals had already been analyzed with some precision4 ,at least1 ,i thought there might be as much as one per cent of the unknown substance in the minerals4 ,but the more we worked1 the clearer we realized that the new radioactive element could exist only in quite minute proportion and that1 in consequence1 its activity must be very great4 ,would we have insisted1 despite the scarcity of our means of research1 if we had known the true proportion of what we were searching for1 no one can tell2 all that can be said now is that the constant progress of our work held us absorbed in a passionate research1 while the difficulties were ever increasing4 ,as a matter of fact1 it was only after several years of most arduous labor that we finally succeeded in completely separating the new substance1 now known to everybody as radium4 ,here is1 briefly1 the story of the search and discovery4 ,as we did not know1 at the beginning1 any of the chemical properties of the unknown substance1 but only that it emits rays1 it was by these rays that we had to search4 ,we first undertook the analysis of a pitchblende from ,st4 ,joachimsthal4 ,analyzing this ore by the usual chemical methods1 we added an examination of its different parts for radioactivity1 by the use of our delicate electrical apparatus4 ,this was the foundation of a new method of chemical analysis which1 following our work1 has been extended1 with the result that a large number of radioactive elements have been discovered4 ,in a few weeks we could be convinced that our prevision had been right1 for the activity was concentrating in a regular way4 ,and1 in a few months1 we could separate from the pitchblende a substance accompanying the bismuth1 much more active than uranium1 and having well defined chemical properties4 ,in ,july1 #ahih1 we announced the existence of this new substance1 to which ,i gave the name of polonium1 in memory of my native country4 ,while engaged in this work on polonium1 we had also discovered that1 accompanying the barium separated from the pitchblende1 there was another new element4 ,after several months more of close work we were able to separate this second new substance1 which was afterwards shown to be much more important than polonium4 ,in ,december1 #ahih1 we could announce the discovery of this new and now famous element1 to which we gave the name of radium4 ,however1 the greatest part of the material work had yet to be done4 ,we had1 to be sure1 discovered the existence of the remarkable new elements1 but it was chiefly by their radiant properties that these new substances were distinguished from the bismuth and barium with which they were mixed in minute quantities4 ,we had still to separate them as pure elements4 ,on this work we now started4 ,we were very poorly equipped with facilities for this purpose4 ,it was necessary to subject large quantities of ore to careful chemical treatment4 ,we had no money1 no suitable laboratory1 no personal help for our great and difficult undertaking4 ,it was like creating something out of nothing1 and if my earlier studying years had once been called by my brother-in-law the heroic period of my life1 ,i can say without exaggeration that the period on which my husband and ,i now entered was truly the heroic one of our common life4 ,we knew by our experiments that in the treatment of pitchblende at the uranium plant of ,st4 ,joachimsthal1 radium must have been left in the residues1 and1 with the permission of the ,austrian government1 which owned the plant1 we succeeded in securing a certain quantity of these residues1 then quite valueless1--and used them for extraction of radium4 ,how glad ,i was when the sacks arrived1 with the brown dust mixed with pine needles1 and when the activity proved even greater than that of the primitive ore6 ,it was a stroke of luck that the residues had not been thrown far away or disposed of in some way1 but left in a heap in the pine wood near the plant4 ,some time later1 the ,austrian government1 on the proposition of the ,academy of ,science of ,vienna1 let us have several tons of similar residues at a low price4 ,with this material was prepared all the radium ,i had in my laboratory up to the date when ,i received the precious gift from the ,american women4 ,the ,school of ,physics could give us no suitable premises1 but for lack of anything better1 the ,director permitted us to use an abandoned shed which had been in service as a dissecting room of the ,school of ,medicine4 ,its glass roof did not afford complete shelter against rain2 the heat was suffocating in summer1 and the bitter cold of winter was only a little lessened by the iron stove1 except in its immediate vicinity4 ,there was no question of obtaining the needed proper apparatus in common use by chemists4 ,we simply had some old pine-wood tables with furnaces and gas burners4 ,we had to use the adjoining yard for those of our chemical operations that involved producing irritating gases2 even then the gas often filled our shed4 ,with this equipment we entered on our exhausting work4 ,yet it was in this miserable old shed that we passed the best and happiest years of our life1 devoting our entire days to our work4 ,often ,i had to prepare our lunch in the shed1 so as not to interrupt some particularly important operation4 ,sometimes ,i had to spend a whole day mixing a boiling mass with a heavy iron rod nearly as large as myself4 ,i would be broken with fatigue at the day's end4 ,other days1 on the contrary1 the work would be a most minute and delicate fractional crystallization1 in the effort to concentrate the radium4 ,i was then annoyed by the floating dust of iron and coal from which ,i could not protect my precious products4 ,but ,i shall never be able to express the joy of the untroubled quietness of this atmosphere of research and the excitement of actual progress with the confident hope of still better results4 ,the feeling of discouragement that sometimes came after some unsuccessful toil did not last long and gave way to renewed activity4 ,we had happy moments devoted to a quiet discussion of our work1 walking around our shed4 ,one of our joys was to go into our workroom at night2 we then perceived on all sides the feebly luminous silhouettes of the bottles or capsules containing our products4 ,it was really a lovely sight and one always new to us4 ,the glowing tubes looked like faint1 fairy lights4 ,thus the months passed1 and our efforts1 hardly interrupted by short vacations1 brought forth more and more complete evidence4 ,our faith grew ever stronger1 and our work being more and more known1 we found means to get new quantities of raw material and to carry on some of our crude processes in a factory1 allowing me to give more time to the delicate finishing treatment4 ,at this stage ,i devoted myself especially to the purification of the radium1 my husband being absorbed by the study of the physical properties of the rays emitted by the new substances4 ,it was only after treating one ton of pitchblende residues that ,i could get definite results4 ,indeed we know to-day that even in the best minerals there are not more than a few decigrammes of radium in a ton of raw material4 ,at last the time came when the isolated substances showed all the characters of a pure chemical body4 ,this body1 the radium1 gives a characteristic spectrum1 and ,i was able to determine for it an atomic weight much higher than that of the barium4 ,this was achieved in #aijb4 ,i then possessed one decigramme of very pure radium chloride4 ,it had taken me almost four years to produce the kind of evidence which chemical science demands1 that radium is truly a new element4 ,one year would probably have been enough for the same purpose1 if reasonable means had been at my disposal4 ,the demonstration that cost so much effort was the basis of the new science of radioactivity4 ,in later years ,i was able to prepare several decigrammes of pure radium salt1 to make a more accurate determination of the atomic weight and even to isolate the pure radium metal4 ,however1 #aijb was the year in which the existence and character of radium were definitely established4 ,we had been able to live for several years entirely engrossed in the work of research1 but gradually circumstances changed4 ,in #aijj my husband was offered a professorship in the ,university of ,geneva1 but almost simultaneously he obtained a position of assistant professor at the ,sorbonne1 and ,i was made professor at the ,normal ,superior ,school for young girls at ,svres4 ,so we remained in ,paris4 ,i became much interested in my work in the ,normal ,school1 and endeavored to develop more fully the practical laboratory exercises of the pupils4 ,these pupils were girls of about twenty years who had entered the school after severe examination and had still to work very seriously to meet the requirements that would enable them to be named professors in the lyces4 ,all these young women worked with great eagerness1 and it was a pleasure for me to direct their studies in physics4 ,but a growing notoriety1 because of the announcement of our discoveries1 began to trouble our quiet work in the laboratory1 and1 little by little1 life became more difficult4 ,in #aijc ,i finished my doctor's thesis and obtained the degree4 ,at the end of the same year the ,nobel prize was awarded jointly to ,becquerel1 my husband and me for the discovery of radioactivity and new radioactive elements4 ,this event greatly increased the publicity of our work4 ,for some time there was no more peace4 ,visitors and demands for lectures and articles interrupted every day4 ,the award of the ,nobel prize was a great honor4 ,it is also known that the material means provided by this prize was much greater than is usual in prizes for science4 ,this was a great help in the continuation of our researches4 ,unhappily1 we were overtired and had a succession of failures of health for the one or the other of us1 so that it was not until #aije that we were able to go to ,stockholm1 where my husband gave his ,nobel lecture and where we were well received4 ,the fatigue resulting from the effort exceeding our forces1 imposed by the unsatisfactory conditions of our labor1 was augmented by the invasion of publicity4 ,the overturn of our voluntary isolation was a cause of real suffering for us and had all the effect of disaster4 ,it was serious trouble brought into the organization of our life1 and ,i have already explained how indispensable was our freedom from external distraction1 in order to maintain our family life and our scientific activity4 ,of course1 people who contribute to that kind of trouble generally mean it kindly4 ,it is only that they do not realize the conditions of the problem4 ,in #aijd our second daughter4 ,eve ,denise1 came to us4 ,i had1 of course1 to interrupt my work in the laboratory for a while4 ,in the same year1 because of the awarding of the ,nobel prize and the general public recognition1 a new chair of physics was created in ,sorbonne1 and my husband was named as its occupant4 ,at the same time ,i was named chief of work in the laboratory that was to be created for him4 ,but in reality the laboratory was not constructed then1 and only a few rooms taken from other uses were available to us4 ,in #aijf just as we were definitely giving up the old shed laboratory where we had been so happy1 there came the dreadful catastrophe which took my husband away from me and left me alone to bring up our children and1 at the same time1 to continue our work of research4 ,it is impossible for me to express the profoundness and importance of the crisis brought into my life by the loss of the one who had been my closest companion and best friend4 ,crushed by the blow1 ,i did not feel able to face the future4 ,i could not forget1 however1 what my husband used sometimes to say1 that1 even deprived of him1 ,i ought to continue my work4 ,the death of my husband1 coming immediately after the general knowledge of the discoveries with which his name is associated1 was felt by the public1 and especially by the scientific circles1 to be a national misfortune4 ,it was largely under the influence of this emotion that the ,faculty of ,sciences of ,paris decided to offer me the chair1 as professor1 which my husband had occupied only one year and a half in the ,sorbonne4 ,it was an exceptional decision1 as up to then no woman had held such a position4 ,the ,university by doing this offered me a precious mark of esteem and gave me opportunity to pursue the researches which otherwise might have had to be abandoned4 ,i had not expected a gift of this kind2 ,i never had any other ambition than to be able to work freely for science4 ,the honor that now came to me was deeply painful under the cruel circumstances of its coming4 ,besides ,i wondered whether ,i would be able to face such a grave responsibility4 ,after much hesitation1 ,i decided that ,i ought at least to try to meet the task1 and so ,i began in #aijf my teaching in the ,sorbonne1 as assistant professor1 and two years later ,i was named titular professor4 ,in my new situation the difficulties of my life were considerably augmented1 as ,i alone had now to carry the burden formerly weighing on my husband and me together4 ,the cares of my young children required close vigilance2 in this1 my husband's father1 who continued to live with us1 willingly took his share4 ,he was happy to be occupied with the little girls1 whose company was his chief consolation after his son's death4 ,by his effort and mine1 the children had a bright home1 even if we lived with our inner grief1 which they were too young to realize4 ,the strong desire of my father-in-law being to live in the country1 we took a house with a garden in ,sceaux1 a suburb of ,paris1 from which ,i could reach the city in half an hour4 ,this country life had great advantages1 not only for my father-in-law1 who enjoyed his new surroundings1 and especially his garden1 but also for my girls1 who had the benefit of walks in the open country4 ,but they were more separated from me1 and it became necessary to have a governess for them4 ,this position was filled first by one of my cousins1 and then by a devoted woman who had already brought up the daughter of one of my sisters4 ,both of them were ,polish1 and in this way my daughters learned my native tongue4 ,from time to time1 some one of my ,polish family came to see me in my grief1 and we managed to meet in vacation time1 at the seashore in ,france1 and once in the mountains of ,poland4 ,in #aiaj we suffered the loss of my very dear father-in-law1 after a long illness1 which brought me many sorrowful days4 ,i used to spend at his bedside as much time as ,i could1 listening to his remembrances of passed years4 ,his death affected deeply my elder daughter1 who1 at twelve1 knew the value of the cheerful hours spent in his company4 ,there were few resources for the education of my daughters in ,sceaux4 ,the youngest one1 a small child1 needed principally a hygienic life1 outdoor walks and quite elementary schooling4 ,she had already shown a vivid intelligence and an unusual disposition for music4 ,her elder sister resembled her father in the form of her intelligence4 ,she was not quick1 but one could already see that she had a gift of reasoning power and that she would like science4 ,she had some training in a private school in ,paris1 but ,i had not wanted to keep her in a lyce1 as ,i have always found the class hours in these schools too long for the health of the children4 ,my view is that in the education of children the requirement of their growth and physical evolution should be respected1 and that some time should be left for their artistic culture4 ,in most schools1 as they exist to-day1 the time spent in various reading and writing exercises is too great1 and the study required to be done at home too much4 ,i also find these schools lacking1 in general1 in practical exercises to accompany the scientific studies4 ,with a few friends in the university circle who shared these views1 we organized1 therefore1 a cooperative group for the education of our children1 each of us taking charge of the teaching of a particular subject to all of the young people4 ,we were all very busy with other things1 and the children varied in age4 ,nevertheless1 the little experiment thus made was very interesting4 ,with a small number of classes we yet succeeded in reuniting the scientific and literary elements of a desirable culture4 ,the courses in science were accompanied by practical exercises in which the children took great interest4 ,this arrangement1 which lasted two years1 proved to be very beneficial for most of the children2 it was certainly so for my elder daughter4 ,following this preparation1 she was able to enter a higher class in one of the collges of ,paris1 and had no difficulty in passing her bachelor's examination before the usual age1 after which she continued her scientific studies in the ,sorbonne4 ,my second daughter1 although not benefiting by a similar arrangement for her earlier studies1 at first followed the classes of a collge only partially1 and later completely4 ,she showed herself a good pupil1 doing satisfactory work in all directions4 ,i wanted very much to assure for my children a rational physical education4 ,next to outdoor walks1 ,i attach a great importance to gymnastics and sports4 ,this side of a girl's education is still rather neglected in ,france4 ,i took care that my children did gymnastics regularly4 ,i was also careful to have them spend vacations either in the mountains or at the seashore4 ,they can canoe and swim very well and are not afraid of a long walk or a bicycle ride4 ,but of course the care of my children's education was only a part of my duties1 my professional occupations taking most of my time4 ,i have been frequently questioned1 especially by women1 how ,i could reconcile family life with a scientific career4 ,well1 it has not been easy2 it required a great deal of decision and of self-sacrifice4 ,however1 the family bond has been preserved between me and my now grown-up daughters1 and life is made brighter by the mutual affection and understanding in our home1 where ,i could not suffer a harsh word or selfish behavior4 ,in #aijf1 when ,i succeeded my husband at the ,sorbonne1 ,i had only a provisional laboratory with little space and most limited equipment4 ,a few scientists and students had already been admitted to work there with my husband and me4 ,with their help1 ,i was able to continue the course of research with good success4 ,in #aijg1 ,i received a precious mark of sympathy from ,mr4 ,andrew ,carnegie1 who donated to my laboratory an annual income for research fellowships which enabled some advanced students or scientists to devote their whole time to investigation4 ,such foundations are very encouraging to those whose inclinations and talents are such as to warrant their entire devotion to research work4 ,they ought to be multiplied in the interest of science4 ,as for myself1 ,i had to devote again a great deal of time to the preparation of several decigrammes of very pure radium chloride4 ,with this ,i achieved1 in #aijg1 a new determination of the atomic weight of radium1 and in #aiaj ,i was able to isolate the metal4 ,the operation1 an extremely delicate one1 was performed with the assistance of a distinguished chemist belonging to the laboratory staff4 ,it has never been repeated since that time1 because it involves a serious danger of loss of radium1 which can be avoided only with utmost care4 ,so ,i saw at last the mysterious white metal1 but could not keep it in this state1 for it was required for further experiments4 ,as for the polonium1 ,i have not been able to isolate it1 its quantity in the mineral being even much less than the quantity of radium4 ,however1 very concentrated polonium has been prepared in my laboratory1 and important experiments have been performed with this substance1 concerning especially the production of helium by radiation of polonium4 ,i had to devote special care to the improvement of the measuring methods in the laboratory4 ,i have told how important precise measurements were in the discovery of radium4 ,it is still to be hoped that efficient methods of quantitative determination may lead to new discoveries4 ,i devised a very satisfactory method for determining the quantity of radium by the means of a radioactive gas produced by it and called emanation4 ,this method1 frequently used in my laboratory1 permits of the measurement of very small quantities of radium 7less than a thousandth of a milligramme71 with a fair precision4 ,more important quantities are often measured by their penetrating radiation1 named ,gamma-rays4 ,for this we also possess in my laboratory a suitable equipment4 ,it is easier and more satisfactory to measure the radium by the emitted rays1 than to weigh it in a balance4 ,however1 these measurements require the disposition of reliable standards4 ,so the question of a radium standard had to be taken into careful consideration4 ,the measurements of radium had to be established on a solid basis1 for the benefit of laboratories and scientific research1 which1 of course1 is in itself an important reason1 and moreover1 the growing medical utilization of this substance made it necessary to control the relative purity of commercially produced radium4 ,the first experiments on the biological properties of radium were successfully made in ,france with samples from our laboratory1 while my husband was living4 ,the results were1 at once1 encouraging1 so that the new branch of medical science1 called radiumtherapy 7in ,france1 ,curietherapy71 developed rapidly1 first in ,france and later in other countries4 ,to supply the radium wanted for this purpose1 a radium-producing industry was established4 ,the first plant was created in ,france and worked very successfully1 but afterwards manufactures were founded in other countries1 the most important of which are now in ,america1 where great quantities of radium ore1 named carnotite1 are available4 ,the radiumtherapy and the radium production developed conjointly1 and the results were more and more important1 for the treatment of several diseases1 and particularly of cancer4 ,as a consequence of this1 several institutes have been founded1 in the large cities1 for the application of the new therapy4 ,some of these institutes own several grammes of radium1 the commercial price of the gramme being now about #gj1jjj1 the cost of production depending on the very small proportion of radium in the ore4 ,it may be easily understood how deeply ,i appreciated the privilege of realizing that our discovery had become a benefit to mankind1 not only through its great scientific importance1 but also by its power of efficient action against human suffering and terrible disease4 ,this was indeed a splendid reward for our years of hard toil4 ,the success of the therapy depends1 of course1 on the precise knowledge of the quantity of radium which is used1 so that the measurements of radium are as important for industry and for medicine as for physicochemical research4 ,considering all these needs1 a commission of scientific men of different countries was formed who agreed to take as a base an international standard1 formed of a carefully weighed quantity of pure radium salt4 ,secondary standards were then to be prepared for each country1 and compared to the basic standard by means of their radiation4 ,i was appointed to prepare the primary standard4 ,this was a very delicate operation1 as the weight of the standard sample1 quite small 7about #ba milligrammes of chloride71 had to be determined with great precision4 ,i performed the preparation in #aiaa4 ,the standard is a thin glass tube1 of a few centimeters in length1 containing the pure salt which was used for the determination of atomic weight4 ,it was accepted by the ,commission and is deposited in the ,international ,bureau of ,weights and ,measures at ,svres1 near ,paris4 ,several secondary standards1 compared with the primary one1 have been put into service by the ,commission4 ,in ,france the control of radium tubes1 by the measurement of their radiation1 takes place in my laboratory1 where any one may bring the radium to be tested2 in the ,united ,states this is done in the ,bureau of ,standards4 ,near the end of the year #aiaj1 ,i was proposed for the decoration of the ,lgion of ,honor4 ,a similar proposal was made earlier in favor of my husband1 who1 however1 being opposed to all honorary distinctions1 did not accept the nomination4 ,as my husband and ,i were too united in all things for me to act differently from him in this matter1 ,i did not accept the decoration1 in spite of the insistence of the ,ministry4 ,at that time also1 several colleagues persuaded me to be a candidate for election to the ,academy of ,sciences of ,paris1 of which my husband was a member during the last months of his life4 ,i hesitated very much1 as such a candidacy requires1 by custom1 a great number of personal visits to ,academy members4 ,however1 ,i consented to offer myself a candidate1 because of the advantages an election would have for my laboratory4 ,my candidacy provoked a vivid public interest1 especially because it involved the question of the admission of women to the ,academy4 ,many of the ,academicians were opposed to this in principle1 and when the scrutiny was made1 ,i had a few votes less than was necessary4 ,i do not ever wish to renew my candidacy1 because of my strong distaste for the personal solicitation required4 ,i believe that all such elections should be based wholly on a spontaneous decision1 without any personal efforts involved1 as was the case for several ,academies and ,societies which made me a member without any demand or initiative on my part4 ,as a result of all the cares devolving on me1 ,i fell seriously ill at the end of #aiaa1 when1 for the second time1 ,i received1 this time alone1 the award of the ,nobel prize4 ,this was a very exceptional honor1 a high recognition of the discovery of the new elements and of the preparation of pure radium4 ,suffering though ,i was1 ,i went to ,stockholm to receive the prize4 ,the journey was extremely painful for me4 ,i was accompanied by my eldest sister and my young daughter ,irene4 ,the ceremony of delivery of the ,nobel prizes is very impressive1 having the features of a national solemnity4 ,a most generous reception was accorded me1 specially by the women of ,sweden4 ,this was a great comfort to me1 but ,i was suffering so much that when ,i returned ,i had to stay in bed for several months4 ,this grave illness1 as well as the necessities of my children's education1 obliged me to move my home from ,sceaux to ,paris4 ,during the year #aiab ,i had the opportunity of collaborating in the creation of a laboratory of radium at ,warsaw4 ,this laboratory was founded by the ,scientific ,society of ,warsaw which offered me its direction4 ,i could not leave ,france to go back to my native country1 but ,i willingly agreed to occupy myself with the organization of the studies in the new laboratory4 ,in #aiac1 having improved my health1 ,i was able to attend an inauguration fte in ,warsaw1 where a touching reception was given1 leaving me an unforgettable memory of national sentiment which succeeded in creating useful work under particularly difficult political conditions4 ,while still only partially recovered from my illness1 ,i renewed my efforts for the construction of a suitable laboratory in ,paris4 ,finally it was arranged for1 and work began in #aiab4 ,the ,pasteur ,institute wished to be associated with this laboratory1 and1 in accord with the ,university1 it was decided to create an ,institute of ,radium1 with two laboratories1 one of physics and one of biology1 the first to be devoted to studies of the physical and chemical properties of the radioactive elements1 the second to the study of their biological and medical applications4 ,but1 because of the lack of financial means1 the construction work proceeded very slowly1 and was not yet entirely finished when the war broke out in #aiad4 ,,chapter ,,iii ,in #aiad1 it happened1 as it often had in other years1 that my daughters had left ,paris for their summer vacation before me4 ,they were accompanied by their governess1 in whom ,i had all confidence1 and were living in a small house on the seashore in ,brittany1 at a place where there were also the families of several of our good friends4 ,my work did not generally permit me to pass the entire vacation near them without interruption4 ,that year ,i was preparing to join them in the last days of ,july1 when ,i was stopped by the bad political news1 with its premonitions of an imminent military mobilization4 ,it did not seem possible for me to leave under these conditions1 and ,i waited for further events4 ,the mobilization was announced on ,august #ast1 immediately followed by ,germany's declaration of war on ,france4 ,the few men of the laboratory staff and the students were mobilized1 and ,i was left alone with our mechanic who could not join the army because of a serious heart trouble4 ,the historic events that followed are known to every one1 but only those who lived in ,paris through the days of ,august and ,september1 #aiad1 can ever really know the state of mind in the capital and the quiet courage shown by it4 ,the mobilization was a general wave of all ,france passing out to the border for the defense of the land4 ,all our interest now centered on the news from the front4 ,after the uncertainties of the first days this news became more and more grave4 ,first1 it was the invasion of ,belgium and the heroic resistance of that little country2 then the victorious march of the ,german army through the valley of the ,oise toward ,paris2 and soon the departure of the ,french government to ,bordeaux1 followed by the leaving of those ,parisians who could not1 or would not1 face the possible danger of ,german occupation4 ,the overloaded trains took into the country a great number of people1 mostly of the well-to-do class4 ,but1 on the whole1 the people of ,paris gave a strong impression of calm and quiet decision in that fateful year of #aiad4 ,in the end of ,august and the beginning of ,september the weather was radiant1 and under the glorious sky of those days the great city with its architectural treasures seemed to be particularly dear to those who remained in it4 ,when the danger of ,german attack on ,paris became pressing1 ,i felt obliged to put in security the supply of radium then in my laboratory1 and ,i was charged by the government to take it to ,bordeaux for safety4 ,but ,i did not want to be away long1 and hence decided to return immediately4 ,i left by one of the trains that were carrying government staff and baggage1 and ,i well remember the aspect of the national highway which is at intervals in view from the train2 it showed a long line of motor-cars carrying their owners from the capital4 ,arriving at ,bordeaux in the evening1 ,i was very embarrassed with my heavy bag including the radium protected by lead4 ,i was not able to carry it and waited in a public place1 while a friendly ministry employee who came by the same train managed to find a room for me in a private apartment1 the hotels being overcrowded4 ,the next morning ,i hurried to put the radium in a safe place1 and succeeded1 although not without difficulty1 in taking a military train back to ,paris in the evening of the same day4 ,having opportunity for exchanging a few sentences with persons on the place who wanted to ask information from people coming by the train1 ,i was interested to notice how they seemed surprised and comforted to learn of some one who found it natural to return to ,paris4 ,my trip back was troubled by delays2 for several hours the train rested immovable on the rails1 while the travelers accepted a little bread from the soldiers who were provided with it4 ,finally arriving in ,paris1 ,i learned that the ,german army had turned2 the battle of the ,marne had begun4 ,in ,paris ,i shared the alternating hope and grief of the inhabitants during the course of that great battle1 and had the constant worry of foreseeing a long separation from my children in case the ,germans succeeded in occupying the city4 ,yet ,i felt that ,i must stay at my post4 ,after the successful outcome of the battle1 however1 any immediate danger of occupation being removed1 ,i was able to have my daughters come back from ,brittany to ,paris and again take up their studies4 ,this was the great desire of my children1 who did not want to stay away from me and from their work1 even if many other families thought it wiser to stay in the country1 far from the front4 ,the dominant duty imposed on every one at that time was to help the country in whatever way possible during the extreme crisis that it faced4 ,no general instructions to this were given to the members of the ,university4 ,it was left to each to take his own initiative and means of action4 ,i therefore sought to discover the most efficient way to do useful work1 turning my scientific knowledge to most profit4 ,during the rapid succession of events in ,august1 #aiad1 it was clearly proved that the preparation for defense was insufficient4 ,public feeling was especially aroused by the realization of the grave failings which appeared in the organization of the ,health ,service4 ,my own attention was particularly drawn to this situation1 and ,i soon found a field of activity which1 once entered upon1 absorbed the greatest part of my time and efforts until the end of the war1 and even for some time thereafter4 ,the work was the organization of radiologic and radiotherapeutic services for the military hospitals4 ,but ,i also had to make the change1 during these difficult war years1 of my laboratory into the new building of the ,institute of ,radium and to continue1 in the measure possible to me1 regular teaching1 as well as to investigate certain problems especially interesting the military service4 ,it is well known that the ,x-rays offer surgeons and doctors extremely useful means for the examination of the sick and wounded4 ,they make possible the discovery and the exact location of projectiles which have entered the body1 and this is a great help in their extraction4 ,these rays also reveal lesions of bones and of the internal organs and permit one to follow the progress of recovery from internal injuries4 ,the use of the ,x-rays during the war saved the lives of many wounded men2 it also saved many from long suffering and lasting infirmity4 ,to all the wounded it gave a greater chance of recovery4 ,however1 at the beginning of the war1 the ,military ,board of ,health had no organization of radiology1 while the civil organization was also but little developed4 ,radiologic installations existed in only a small number of important hospitals1 and there were only a few specialists in the large cities4 ,the numerous new hospitals that were established all over ,france in the first months of the war had1 as a rule1 no installation for the use of ,x-rays4 ,to meet this need ,i first gathered together all the apparatus ,i could find in the laboratories and stores4 ,with this equipment ,i established in ,august and ,september1 #aiad1 several stations of radiology1 the operation of which was assured by volunteer helpers to whom ,i gave instruction4 ,these stations rendered great service during the battle of the ,marne4 ,but as they could not satisfy the needs of all the hospitals of the ,paris region1 ,i fitted up1 with the help of the ,red ,cross1 a radiologic car4 ,it was simply a touring motor-car1 arranged for the transport of a complete radiologic apparatus1 together with a dynamo that was worked by the engine of the car1 and furnished the electric current necessary for the production of the rays4 ,this car could come at the call of any of the hospitals1 large or small1 in the surroundings of ,paris4 ,cases of urgent need were frequent1 for these hospitals had to take care of the wounded who could not be transported to more distant places4 ,the first results of this work showed that it was necessary to do more4 ,thanks to special donations and to the help of a very efficient relief committee called le ,patronage ,national des ,blesss1 ,i succeeded in developing my initiative to a considerable extent4 ,about two hundred radiologic installations were established or materially improved through my efforts in the zone of the ,french and ,belgian armies1 and in the regions of ,france not occupied by the army4 ,i was able1 besides1 to equip in my laboratory and give to the army twenty radiologic cars4 ,the frames of these cars were donated by various persons who wished to be helpful2 some of them offered also the equipment4 ,the cars were of the greatest service to the army4 ,these privately developed installations were particularly important in the first two years of the war1 when the regular military service possessed but few radiologic instruments4 ,later the ,board of ,health created1 little by little1 a considerable radiologic service of its own1 as the utility of the stations was more clearly realized owing to the example given by private initiative4 ,but the needs of the armies were so great1 that my cooperation continued necessary to the end of the war1 and even afterwards4 ,i could not have accomplished this work without seeing for myself the needs of the ambulance stations and hospitals4 ,thanks to the help of the ,red ,cross and to the agreement of the ,board of ,health1 ,i was able to make several journeys to the army zones and to the other parts of ,france4 ,several times ,i visited the ambulance stations of the armies of the north and in the ,belgian zone1 going to ,amiens1 ,calais1 ,dunkirk1 ,furnes1 and ,poperinghe4 ,i went to ,verdun1 ,nancy1 ,luneville1 ,belfort1 to ,compiegne1 and ,villers-,cotterets4 ,in the regions distant from the front1 ,i took care of many hospitals which had to do very intensive work with little aid4 ,and ,i keep as a precious recollection of that time1 many letters of warm recognition from those to whom ,i brought help in their difficulties4 ,the motive of my starting on a journey was usually a demand from surgeons4 ,i went with a radiologic car which ,i kept for my personal use4 ,in examining the wounded in the hospital1 ,i could gain information of the special needs of the region4 ,when back in ,paris1 ,i got the necessary equipment to meet these needs and returned to install it myself1 for very often the people on the ground could not do it4 ,i had then to find competent persons to handle the apparatus and show them how to do it1 in full detail4 ,after a few days of hard toil1 the manipulator knew enough to work the apparatus himself1 and at the same time a large number of wounded had been examined4 ,in addition1 the surgeons of the region had gained an idea of the usefulness of the radiologic examination 7which few of them knew at that time71 and friendly relations were established which made the later development of my work much easier4 ,on several of my trips ,i was accompanied by my elder daughter1 ,irene1 who was then seventeen years old1 and1 having finished her preparatory studies1 was beginning higher studies at the ,sorbonne4 ,because she greatly desired to be useful1 she now studied nursing and learned radiology1 and did her best to help me under the most varied circumstances4 ,she did ambulance work at the front between ,furnes and ,ypres1 and also at ,amiens1 receiving1 from the ,chiefs of ,service1 testimonials of work satisfactorily performed and1 at the end of the war1 a medal4 ,of the hospital life of those years1 we keep many a remembrance1 my daughter and ,i4 ,traveling conditions were extraordinarily difficult2 we were often not sure of being able to press forward1 to say nothing of the uncertainty of finding lodgings and food4 ,however1 things always ended in arranging themselves1 thanks to our persistence and to the good will we met4 ,wherever we went ,i had to look after each detail myself and see innumerable military chiefs to obtain passes and permissions for transportation4 ,many a time ,i loaded my apparatus on to the train myself1 with the help of the employees1 to make sure that it would go forward instead of remaining behind several days at the station4 ,and on arrival ,i also went to extract them from the encumbered station4 ,when ,i traveled with the radiologic car1 other problems presented themselves4 ,i had1 for instance1 to find safe places for the car1 to get lodgings for the assistants and to secure the automobile accessories4 ,since chauffeurs were scarce1 ,i learned to drive the car1 and did it when necessary4 ,owing to all this personal supervision1 my installations were usually swiftly made1 whereas appeal to the ,central ,health ,service was answered slowly4 ,so the military chiefs greatly appreciated the assistance they could get from me1 especially in cases of urgent need4 ,we both1 my daughter and myself1 have pleasant and grateful memories of the personnel of the hospitals1 and were on the best terms with the surgeons and nurses4 ,one could not but admire these men and women who were giving their services without counting1 and whose task was often overwhelming4 ,our collaboration was easy1 for my daughter and ,i tried to work in their spirit2 and we felt that we were standing side by side with friends4 ,while we were attached to the ,belgian ,ambulance ,service1 we were present several times during visits of ,king ,albert and ,queen ,elizabeth4 ,we appreciated deeply their devotion1 their solicitude for the wounded1 their extreme simplicity1 and the cordiality of their behavior4 ,but nothing was so moving as to be with the wounded and to take care of them4 ,we were drawn to them because of their suffering and because of the patience with which they bore it4 ,almost everyone did his best to facilitate the ,x-ray examination1 notwithstanding the pain caused by any displacement4 ,one learned very soon to know them individually and to exchange with them a few friendly words4 ,those who were not familiar with the examination1 wanted very much to be reassured about the effect of the strange apparatus they were going to experience4 ,i can never forget the terrible impression of all that destruction of human life and health4 ,to hate the very idea of war1 it ought to be sufficient to see once what ,i have seen so many times1 all through those years3 men and boys brought to the advanced ambulance in a mixture of mud and blood1 many of them dying of their injuries1 many others recovering but slowly through months of pain and suffering4 ,one of my difficult problems was to find the necessary trained assistants to operate my apparatus4 ,at the beginning of the war there was little knowledge of radiology1 and apparatus in the hands of those who did not understand how to handle it deteriorated quickly and was soon useless4 ,the practice of radiology in most hospitals in war-time does not require much medical knowledge2 it can be sufficiently grasped by intelligent persons who know how to study and who have some notion of electrical machinery4 ,professors1 engineers1 or university students often made good manipulators4 ,i had to look for those who were temporarily free from military service1 or who happened to be stationed in the locality where ,i needed them4 ,but even after ,i had secured them1 these operators were often transferred by military orders1 and ,i had to search again for others to fill their places4 ,for this reason1 ,i determined to train women to do this work4 ,accordingly1 ,i proposed to the ,health ,service to add a department of radiology to the ,nurses' ,school which had just been founded at the ,edith ,cavell ,hospital4 ,this they agreed to do4 ,and so1 in #aiaf1 the course was organized at the ,radium ,institute1 and provided in the following years of war for the training of one hundred and fifty operators4 ,most of the pupils who applied had only an elementary education1 but could succeed if working in a proper way4 ,the course comprised theoretical studies and very extended practical training2 it included also some instruction in anatomy4 ,it was given by a few persons of good will1 among them my daughter4 ,our graduates formed an excellent personnel very genuinely appreciated by the ,board of ,health4 ,theoretically1 they were supposed to serve as aides to physicians1 but several of them proved capable of independent work4 ,my continued and various experience in war radiology gave me a wide knowledge of that subject1 which ,i felt should be made more familiar to the public4 ,so ,i wrote a small book called ,radiology and the ,war1 in which ,i aimed to demonstrate the vital importance of radiology and to compare its development during war time with its use in the previous time of peace4 ,i come now to the account of the founding of the service of radiumtherapy at the ,radium ,institute4 ,in #aiae1 the radium1 which had been safely deposited in ,bordeaux1 was brought back to ,paris1 and not having time for regular scientific research1 ,i decided to use it to cure the wounded1 without1 however1 risking the loss of this precious material4 ,i proceeded to place at the disposal of the ,health ,service not the radium itself1 but the emanation which can be obtained from it at regular intervals4 ,the technique of the use of the emanation can readily be employed in the larger radiumtherapy institutes1 and1 in many ways1 is more practicable than the direct use of radium4 ,in ,france1 however1 there was no national institute of radiumtherapy1 and the emanation was not used in hospitals4 ,i offered to furnish regularly to the ,health ,service bulbs of radium emanation4 ,the offer was accepted1 and the ,emanation ,service1 started in #aiaf1 was continued until the end of the war and even longer4 ,having no assistants1 ,i had1 for a long time1 to prepare these emanation bulbs alone1 and their preparation is very delicate4 ,numbers of wounded and sick1 military and civil1 were treated by means of these bulbs4 ,during the bombardment of ,paris1 the ,health ,board took special measures to protect from shells the laboratory in which the bulbs were prepared4 ,since the handling of radium is far from being free of danger 7several times ,i have felt a discomfort which ,i consider a result of this cause71 measures were taken to prevent harmful effects of the rays on the persons preparing emanation4 ,while the work in connection with the hospitals remained my major interest1 ,i had many other preoccupations during the war4 ,after the failure of the ,german offensive in the summer of #aiah1 at the request of the ,italian government1 ,i went to ,italy to study the question of her natural resources in radioactive materials4 ,i remained a month and was able to obtain certain results in interesting the public authorities in the importance of this new subject4 ,it was in #aiae that ,i had to move my laboratory to the new building in the rue ,pierre ,curie4 ,this was a trying and complicated experience1 for which1 once more1 ,i had no money nor any help4 ,so it was only between my journeys that ,i was able1 little by little1 to do the transportation of my laboratory equipment1 in my radiologic cars4 ,afterwards1 ,i had much work in classifying and distributing my materials1 and arranging the new place in general1 with the help of my daughter and of my mechanic1 who1 unfortunately1 was often ill4 ,one of my first cares was to have trees planted in the limited grounds of my laboratory4 ,i feel it very necessary for the eyes to have the comfort of fresh leaves in spring and summer time4 ,so ,i tried to make things pleasant for those who were to work in the new building4 ,we planted a few lime trees and plane trees1 as many as there was room for1 and did not forget flowerbeds and roses4 ,i well remember the first day of bombardment of ,paris with the big ,german gun2 we had gone1 in the early morning1 to the flower-market1 and spent all that day busy with our plantation1 while a few shells fell in the vicinity4 ,in spite of the great difficulties1 the new laboratory was organized little by little1 and ,i had the satisfaction of having it quite ready for the beginning of the school-year #aiai-bj1 the period of demobilization4 ,in the spring of #aiai1 ,i organized special courses for some ,american soldier students1 who also studied with much zeal the practical exercises directed by my daughter4 ,illustration3 ,photo by ,u4 ,s4 ,signal ,corps4 ,mme4 ,curie instructing ,american soldiers in her ,paris laboratory4 ,the entire period of the war was for me1 as for many others1 a period of great fatigue4 ,i took almost no vacation1 except for a few days1 now and then1 when ,i went to see my daughters on their holidays4 ,my older daughter would scarcely take any1 and ,i was obliged to send her away sometimes to preserve her health4 ,she was continuing her studies in the ,sorbonne1 and besides1 as said before1 was helping me with my war work1 while the younger daughter was still in the preparatory college4 ,neither of them wished to leave ,paris during the bombardment4 ,after more than four years of a war which caused ravages without precedent1 the armistice came at last1 in the autumn of #aiah1 followed by laborious efforts to restablish peace1 which is not yet general nor complete4 ,it was a great relief to ,france to see the end of that dark period of cruel losses4 ,but the griefs are too recent and life still too hard for calm and happiness yet to be restored4 ,nevertheless1 a great joy came to me as a consequence of the victory obtained by the sacrifice of so many human lives4 ,i had lived1 though ,i had scarcely expected it1 to see the reparation of more than a century of injustice that had been done to ,poland1 my native country1 and that had kept her in slavery1 her territories and people divided among her enemies4 ,it was a deserved resurrection for the ,polish nation1 which showed herself faithful to her national memories during the long period of oppression1 almost without hope4 ,the dream that appeared so difficult to realize1 although so dear1 became a reality following the storm that swept over ,europe4 ,in these new conditions ,i went to ,warsaw and saw my family again1 after many years of separation1 in the capital of free ,poland4 ,but how difficult are the conditions of life of the new ,polish republic1 and how complicated is the problem of reorganization after so many years of abnormal life6 ,in ,france1 partly devastated and suffering from the loss of so many of her citizens1 the difficulties created by the war are not yet effaced1 and the return to normal work is being attained only gradually4 ,the scientific laboratories feel this state of affairs and the same condition prevails for the ,radium ,institute4 ,the various radiologic organizations created during the war still partially exist4 ,the ,radiographic ,nurses' ,school has been maintained at the request of the ,board of ,health4 ,the emanation service1 which could not be abandoned1 is also continued in a considerably enlarged form4 ,it has passed under the direction of ,doctor ,regaud1 ,director of the ,pasteur ,laboratory of the ,radium ,institute1 and is developing into a great national service of radiumtherapy4 ,the work of the laboratory has been reorganized1 with the return of the mobilized personnel and the students4 ,but in the restrained circumstances under which the country still exists1 the laboratory lacks ways and means for its efficient development4 ,particularly are wanted an independent hospital for radiumtherapy 7which is called ,curietherapy in ,france71 and an experimental station1 outside of ,paris1 for experiments on great quantities of material1 such as are needed for the progress of our knowledge of radioactive elements4 ,i myself am no longer young1 and ,i frequently ask myself whether1 in spite of recent efforts of the government aided by some private donations1 ,i shall ever succeed in building up for those who will come after me an ,institute of ,radium1 such as ,i wish to the memory of ,pierre ,curie and to the highest interest of humanity4 ,however1 a precious encouragement came to me in the year #aiba4 ,on the initiative of a generous daughter of the ,united ,states1 ,mrs4 ,w4 ,b4 ,meloney1 the women of that great ,american country collected a fund1 the ,marie ,curie ,radium ,fund1 and offered me the gift of a gramme of radium to be placed entirely at my disposal for scientific research4 ,mrs4 ,meloney invited me with my daughters to come to ,america and to receive the gift1 or the symbol of it1 from the hands of the ,president of the great republic1 at the ,white ,house4 ,the fund was collected by a public subscription1 as well by small as by important gifts1 and ,i was very thankful to my sisters of ,america for this genuine proof of their affection4 ,so ,i started for ,new ,york at the beginning of ,may1 after a ceremony given in my honor at the ,opera of ,paris1 to greet me before my departing4 ,i keep a grateful memory of my sojourn in the ,united ,states for several weeks1 of the impressive reception at the ,white ,house1 where ,president ,harding addressed me in generous and affectionate words1 of my visits to the universities and colleges which welcomed me and bestowed on me their honorary degrees1 of the public reunions where ,i could not but feel the deep sympathy of those who came to meet me and to wish me good luck4 ,illustration3 ,henri ,manuel1 ,paris4 ,madame ,curie in her laboratory at the ,institut ,curie1 ,paris4 ,i had also the opportunity of a visit to the ,niagara ,falls and to the ,grand ,canyon1 and admired immensely these marvelous creations of nature4 ,unhappily1 the precarious state of my health did not permit of the complete fulfilment of the general plan established by my visit to ,america4 ,however1 ,i saw and learned much1 and my daughters enjoyed to a full extent the opportunities of their unexpected vacation and the pride in the recognition of their mother's work4 ,we left for ,europe at the end of ,june1 with the real sorrow of parting from excellent friends whom we would not forget4 ,i came back to my work1 made easier by the precious gift1 with an even stronger desire to carry it forward with renewed courage4 ,but as my aims are still wanting support in essential parts1 ,i am frequently compelled to give thought to a very fundamental question concerning the view a scientist ought to take of his discovery4 ,my husband1 as well as myself1 always refused to draw from our discovery any material profit4 ,we have published1 since the beginning1 without any reserve1 the process that we used to prepare the radium4 ,we took out no patent and we did not reserve any advantage in any industrial exploitation4 ,no detail was kept secret1 and it is due to the information we gave in our publications that the industry of radium has been rapidly developed4 ,up to the present time this industry hardly uses any methods except those established by us4 ,the treatment of the minerals and the fractional crystallizations are still performed in the same way1 as ,i did it in my laboratory1 even if the material means are increased4 ,as for the radium prepared by me out of the ore we managed to obtain in the first years of our work1 ,i have given it all to my laboratory4 ,the price of radium is very high since it is found in minerals in very small quantities1 and the profits of its manufacture have been great1 as this substance is used to cure a number of diseases4 ,so it is a fortune which we have sacrificed in renouncing the exploitation of our discovery1 a fortune that could1 after us1 have gone to our children4 ,but what is even more to be considered is the objection of many of our friends1 who have argued1 not without reason1 that if we had guaranteed our rights1 we could have had the financial means of founding a satisfactory ,institute of ,radium1 without experiencing any of the difficulties that have been such a handicap to both of us1 and are still a handicap to me4 ,yet1 ,i still believe that we have done right4 ,humanity1 surely1 needs practical men who make the best of their work for the sake of their own interests1 without forgetting the general interest4 ,but it also needs dreamers1 for whom the unselfish following of a purpose is so imperative that it becomes impossible for them to devote much attention to their own material benefit4 ,no doubt it could be said that these idealists do not deserve riches since they do not have the desire for them4 ,it seems1 however1 that a society well organized ought to assure to these workers the means for efficient labor1 in a life from which material care is excluded so that this life may be freely devoted to the service of scientific research4 ,,chapter ,,iv ,a ,,visit ,,to ,,america ,my beautiful voyage to the ,united ,states of ,america resulted1 as is known1 from the generous initiative of an ,american woman1 ,mrs4 ,meloney1 editor of an important magazine1 the ,delineator1 who1 having planned the gift of a gramme of radium to me by her countrywomen1 succeeded in a few months in bringing this plan to execution1 and asked me to come over and receive the gift personally4 ,the idea was that the gift would come exclusively from the ,american women4 ,a committee including several prominent women and distinguished scientific men received some important gifts1 and made an appeal for a public subscription1 to which a great number of women's organizations1 especially colleges and clubs1 responded4 ,in many cases gifts came from persons who had experienced the benefit of radiumtherapy4 ,in this way was collected the ,marie ,curie ,radium ,fund of more than one hundred thousand dollars for the purchase of a gramme of radium4 ,the ,president of the ,united ,states1 ,mr4 ,harding1 kindly agreed to deliver the gift in a ceremony at the ,white ,house4 ,the ,committee invited me and my daughters to the ,united ,states in ,may1 and even though it was not vacation time for me1 ,i accepted the invitation with the consent of the ,university of ,paris4 ,all care of the voyage was taken away from me4 ,mrs4 ,meloney came to ,france in time to be present at a manifestation organized on the #bhth of ,april in favor of the ,radium ,institute of ,paris by the magazine ,je ,sais ,tout1 and accompanied by sincere expressions of sympathy for the ,american nation4 ,on ,may #dth1 we took passage at ,cherbourg on the ,olympic for ,new ,york4 ,the program of my voyage prepared by the ,committee seemed very intimidating4 ,it was announced that ,i would not only attend the ceremony at the ,white ,house1 but also visit many universities and colleges in several towns4 ,some of these institutions had contributed to the ,fund2 all desired to offer me honors4 ,the vitality and the activity of the ,american nation produces programs on a large scale4 ,on the other hand1 the wideness of the country has developed in ,american citizens the custom of long travel4 ,but during all that travel ,i was protected with the greatest care1 in order to lighten as far as possible the inevitable fatigue of the voyage and the receptions4 ,america not only gave me a generous welcome1 but also true friends whom ,i could not thank enough for their kindness and their devotion4 ,after having admired the grand view of the harbors of ,new ,york1 and having been greeted by groups of students1 ,girl ,scouts1 and ,polish delegates1 and welcomed by many gifts of flowers1 we took possession of a peaceful apartment in town4 ,the following day ,i made the acquaintance of the ,reception ,committee at a luncheon given by ,mrs4 ,carnegie in her beautiful home still filled with memories of her husband1 ,andrew ,carnegie1 whose philanthropic achievements are well known in ,france4 ,the following day we went for a visit of a few days to ,smith ,college1 and ,vassar ,college1 a few hours from ,new ,york4 ,later ,i also visited the colleges of ,bryn ,mawr and ,wellesley1 and ,i saw some others on my way4 ,these colleges1 or universities for women1 are very characteristic of ,american life and culture4 ,my short visit could not permit me to give an authorized opinion on the intellectual training1 but even in such a visit as ,i made one may notice important differences between the ,french and ,american conception of girls' education1 and some of these differences would not be in favor of our country4 ,two points have particularly drawn my attention3 the care of the health and the physical development of the students1 and the very independent organization of their life which allows a large degree of individual initiative4 ,the colleges are excellent in their construction and organization4 ,they are composed of several buildings1 often scattered in very large grounds between lawns and trees4 ,smith is on the shore of a charming river4 ,the equipment is comfortable and hygienic1 of extreme cleanliness1 with bathrooms1 showers1 distribution of cold and hot water4 ,the students have cheerful private rooms and common gathering rooms4 ,a very complete organization of games and sports exists in every college4 ,the students play tennis and baseball2 they have gymnasium1 canoeing1 swimming1 and horseback riding4 ,their health is under the constant care of medical advisers4 ,it seems to be a frequent opinion of ,american mothers that the existing atmosphere of cities like ,new ,york is not favorable to the education of young girls1 and that a life in the country in the open air gives more suitable conditions for the health and the tranquillity of studying4 ,in every college the young girls form an association and elect a committee which has to establish the internal rules of the college4 ,the students display a great activity3 they take part in educational work2 they publish a paper2 they are devoted to songs and music2 they write plays1 and act them in college and out of it4 ,these plays have interested me very much in their subjects and the execution4 ,the students are also of different social conditions4 ,many of them are of wealthy families1 but many others live on scholarships4 ,the whole organization may be considered as democratic4 ,a few students are foreigners1 and we have met some ,french students very well pleased with the college life and the studies4 ,every college takes four years of study with examinations from time to time4 ,some students afterwards do personal work1 and acquire the degree of ,doctor1 which does not exactly correspond to the same title in ,france4 ,the colleges have laboratories with many good facilities for experimentation4 ,i have been strongly impressed by the joy of life animating these young girls and expanding on every occasion1 like that of one of my visit4 ,if the ceremonies of the reception were performed in a nearly military order1 a spontaneity of youth and happiness expressed itself in the songs of greeting composed by the students1 in the smiling and excited faces1 and in the rushing over the lawns to greet me at my arrival4 ,this was indeed a charming impression which ,i could not forget4 ,back in ,new ,york1 several ceremonies awaited me before my leaving for ,washington4 ,a luncheon of the ,chemists1 a reception at the ,museum of ,natural ,history and the ,mineralogical ,club1 a dinner at the ,institute of ,social ,sciences1 and a great meeting at ,carnegie ,hall1 where many delegations represented the faculties and students of women's colleges and universities4 ,at all these receptions ,i was greeted in warm addresses by prominent men and women1 and ,i received honors very precious to me because of the sincerity of the givers4 ,neither has the part of national friendships been forgotten2 the address of ,vice-,president ,coolidge was a noble recognition of the past where ,french and ,polish citizens have been helpful to the young ,american ,republic1 and is also a statement of fraternity strengthened by the tempest of the last years4 ,it was in this atmosphere of affection created by the convergence of intellectual and social sympathies that there took place on ,may #bjth the beautiful ceremony at the ,white ,house4 ,it was a deeply moving ceremony in all its simplicity1 occurring before a democratic gathering including the ,president and ,mrs4 ,harding1 cabinet officers1 ,judges of the ,supreme ,court1 high officers of ,army and ,navy1 foreign diplomats1 representatives of women's clubs and societies1 and prominent citizens of ,washington and other cities4 ,it comprised a short presentation by the ,french ambassador1 ,m4 ,jusserand1 a speech by ,mrs4 ,meloney for the ,american women1 the address of ,president ,harding1 a few words of gratitude said by me1 a defile of the guests1 and a group picture for a souvenir1 all this in the admirable setting of the ,white ,house1 peaceful and dignified1 white indeed between its green lawns with wide prospects on that beautiful afternoon of ,may4 ,a remembrance never to be forgotten was left by this reception in which the chief representative of a great nation offered me homage of infinite value1 the testimonial of the recognition of his country's citizens4 ,the address of the ,president had been inspired by the same sentiments as that of ,vice-,president ,coolidge1 as far as concerned his appreciation of ,france and ,poland4 ,this address gave also an expression of the ,american feeling which was emphasized by an exceptional solemnity in the delivering of the gift4 ,illustration3 ,copyright ,international4 ,mme4 ,curie and ,president ,harding at the ,white ,house1 ,may #bj1 #aiba1 when a gram of radium was presented to its discoverer by the women of ,america4 ,the ,american nation is generous1 and always ready to appreciate an action inspired by considerations of general interest4 ,if the discovery of radium has so much sympathy in ,america1 it is not only because of its scientific value1 and of the importance of medical utilization2 it is also because the discovery has been given to humanity without reservation or material benefits to the discoverers4 ,our ,american friends wanted to honor this spirit animating the ,french science4 ,the radium itself was not brought to the ceremony4 ,the ,president presented me with the symbol of the gift1 a small golden key opening the casket devised for the transportation of the radium4 ,our sojourn at ,washington following the principal ceremony included a very agreeable reception at the ,french ,embassy and the ,polish ,legation1 a reception at the ,national ,museum1 and some laboratory visits4 ,the itinerary of our journey from ,washington included visits to the cities of ,philadelphia1 ,pittsburgh1 ,chicago1 ,buffalo1 ,boston1 and ,new ,haven1 a visit to the ,grand ,canyon1 and to ,niagara ,falls4 ,on that trip ,i was the guest of several universities which did me the honor of bestowing honorary degrees on me4 ,i have to thank for these the universities of ,pennsylvania1 of ,pittsburgh1 of ,chicago1 the ,northwestern ,university1 ,columbia ,university1 ,yale ,university1 the ,women's ,medical ,college of ,pennsylvania1 the ,university of ,pennsylvania1 ,smith ,college1 and ,wellesley ,college1 while ,i thank ,harvard ,university for her reception4 ,the delivery of honorary degrees in ,american universities is accompanied by solemnities4 ,in principle1 the presence of the candidate is required1 and the delivery takes place at the annual commencement1 but1 in some cases1 special ceremonies were organized in my favor4 ,the university ceremonies in ,america are more frequent than in ,france1 and play a more important part in the university life4 ,especially is this true at the annual commencement1 which begins with an academic procession over the grounds of the university1 the procession including the officials1 the professors1 and graduates in academic caps and gowns4 ,afterwards all assemble in a hall where are announced the diplomas corresponding to the grades of bachelor1 master1 and doctor4 ,there is always a musical part in the program1 and addresses are delivered by the officials of the university or invited orators4 ,these addresses are naturally devoted to dignifying the ideals and the humanitarian purposes of education2 but in certain cases it seems permitted to introduced point of ,american humor4 ,these ceremonies are on the whole very impressive1 and certainly contribute to keep a bond between the university and the alumni4 ,this is a favorable circumstance for those great ,american universities which are sustained entirely on private foundations4 ,it is only in more recent times that most ,states have created universities supported by the ,state4 ,at ,yale ,university ,i had the pleasure of representing the ,university of ,paris at the inauguration of ,president ,angell1 fourteenth president of the ,university4 ,i was also pleased to attend at ,philadelphia a meeting of the ,american ,philosophical ,society and a meeting of the ,college of ,physicians1 and at ,chicago a meeting of the ,american ,chemical ,society at which ,i delivered a lecture on the ,discovery of ,radium4 ,the medals of ,john ,scott1 ,benjamin ,franklin1 and ,willard ,gibbs have been presented to me by these societies4 ,several meetings organized in my honor by the ,american women's organizations have particularly interested the ,american public4 ,i have already mentioned the meeting of the ,university ,women at ,carnegie ,hall of ,new ,york2 a similar meeting was held at ,chicago1 where ,i was also received by the ,association of ,polish ,women4 ,i was also greeted by women's organizations in the ,carnegie ,institute of ,pittsburgh1 and by a delegation of ,canadian university women at ,buffalo4 ,in all these meetings it was impossible not to recognize the sincerity of the emotion in the women who gave me their best wishes1 at the same time expressing their confidence in the future of feminine intelligence and activity4 ,i did not feel any opposition between these feministic aspirations and the masculine opinion4 ,as far as ,i could notice1 the men in ,america approve of these aspirations and encourage them4 ,this is a very favorable condition for the social activity of the ,american women which reveals itself in a strong interest in work for education1 for hygiene1 and for the improvement of conditions of labor4 ,but any other unselfish purpose may rely on their support1 as is proved by the success of ,mrs4 ,meloney's plan1 and by the sympathy this plan encountered in women of all social conditions4 ,i could not1 to my deep regret1 give time enough to the visit to laboratories and scientific institutes4 ,these too brief visits were of great interest to me4 ,i found everywhere the greatest care for developing scientific activity and for improving the facilities4 ,new laboratories are in building1 and in older laboratories very modern equipment may be found4 ,the available room never gives that impression of insufficiency from which we suffer too often in ,france4 ,the means are provided by private initiative expressed in gifts and foundations of various kinds4 ,there exists also a ,national ,council of ,research established by private funds for stimulating and improving scientific work1 and for assuring its connection with industry4 ,i have visited with special interest the ,bureau of ,standards1 a very important national institution at ,washington for scientific measurements and for study connected with them4 ,the tubes of radium presented to me were at the ,bureau1 whose officials had kindly offered to make the measurements1 and to take care of the packing and delivery to the ship4 ,a new laboratory has been created at ,washington for researches on very low temperatures with the use of liquid hydrogen and liquid helium4 ,i had the honor of dedicating this laboratory to its service4 ,i had the great pleasure of meeting in their laboratories several very important ,american scientific men4 ,the hours ,i spent in their company are among the best of my travel4 ,the ,united ,states possesses several hospitals for radiumtherapy4 ,these hospitals are generally provided with laboratories for the extraction of radium emanation which is sealed up in small tubes for medical use4 ,these institutions own important quantities of radium1 have a very good equipment1 and treat a great number of patients4 ,i have visited some of them1 and this made me feel more deeply1 if possible1 the regret of not having in ,france even one national institute capable of rendering the same services4 ,i hope that this lack will be filled in the near future4 ,the industry of radium has been started in ,france1 but it is in ,america that it has had its greatest development1 owing to the presence of a sufficient supply of the ore carnotite4#ae ,i was very much interested in my visit to the most important of the factories1 and ,i gladly recognize the spirit of initiative in this undertaking4 ,the factory owns a collection of documentary films which enable one to appreciate the effort made each day in collecting the ore scattered in the immense fields of ,colorado1 in carrying and concentrating this ore originally very poor in radium4 ,on the other hand1 the means of extraction of radium are still the same which have been described in earlier chapters4 ,the greatest courtesy was paid me in my visit to the radium plant and laboratory4 ,i found the same reception at a factory of mesothorium which presented me with some material1 and where the officials expressed the desire to help in my scientific work4 ,to make complete these travel impressions it would be necessary to speak of the nature of the country4 ,i recoil before the task1 being incapable of expressing in a few words the immensity and the variety of the spaces which opened before my eyes4 ,the general impression is one of unlimited possibilities for the future4 ,i keep a particularly vivid remembrance of the great falls of ,niagara1 and of the magnificent colors of the ,grand ,canyon4 ,on ,june #bhth ,i embarked in ,new ,york on the same ship which had brought me to the ,united ,states less than two months before4 ,i would not take the liberty1 after so short a period of time1 of giving an opinion on ,america and the ,americans4 ,i would only say how deeply ,i have been touched by the warm reception which was tendered everywhere to me and my daughters4 ,our hosts wanted to make us feel that we were not with strangers2 and1 on the other hand1 many of them assured me that they felt in entirely friendly surroundings when on the soil of ,france4 ,i got back to ,france with a feeling of gratitude for the precious gift of the ,american women1 and with a feeling of affection for their great country tied with ours by a mutual sympathy which gives confidence in a peaceful future for humanity4 ,footnote #ae3 ,quite recently there has been started near ,anverst an important radium industry as a result of the discovery of uranium ore in the ,belgian ,congo4