,illustration ,this etext was created by ,gregory ,walker1 ,austin1 ,texas1 for the ,digital ,daguerreian ,archive ,project4 ,page numbers explicitly referred to in the text are marked at their beginning by 8page 0 on a separate line4 ,i hope this etext inspires a wider interest in the origins of photography and in the modern practice of the ,daguerreian ,art4 ,updater's note3 ,in this version1 the above page numbering convention has been replaced by 80 sequences placed in line with the surrounding text4 ,,american ,,hand ,,book ,,of ,,the ,,daguerreotype ,,giving ,,the ,,most ,,approved ,,and ,,convenient ,,methods ,,for ,,preparing ,,the ,,chemicals1 ,,and ,,the ,,combinations ,,used ,,in ,,the ,,art4 ,,containing ,,the ,,daguerreotype1 ,,electrotype1 ,,and ,,various ,,other ,,processes ,,employed ,,in ,,taking ,,heliographic ,,impressions4 ,,by ,s4 ,d4 ,,humphrey ,,fifth ,,edition ,,new ,,york3 ,,published ,,by ,s4 ,d4 ,,humphrey #cg ,,lispenard ,,street #aheh ,entered1 according to ,act of ,congress1 in the year #aheh1 by ,s4 ,d4 ,,humphrey1 ,in the ,clerk's ,office of the ,district ,court of the ,southern ,district of ,new ,york4 ,to ,j4 ,,gurney1 ,,whose ,,professional ,,skill1 ,,scientific ,,accuracy1 ,,and ,,energetic ,,perseverance1 ,,have ,,won ,,for ,,him ,,universal ,,esteem1 ,,this ,,work ,,is ,,most ,,respectfully ,,inscribed4 ,,preface4 ,there is not an ,amateur or practical ,daguerreotypist1 who has not felt the want of a manual--,hand ,book1 giving concise and reliable information for the processes1 and preparations of the ,agents employed in his practice4 ,since portraits by the ,daguerreotype are at this time believed to be more durable than any other style of 8,sun-drawing10 the author has hit upon the present as being an appropriate time for the introduction of the ,fifth ,edition of this work4 ,the earlier edition having a long since been wholly2 exhausted1 the one now before you is presented4 ,the endeavor has been to point out the readiest and most approved ,methods of ,operation1 and condense in its pages2 as much practical information as its limits will admit4 ,an extended ,preface is unnecessary1 since the aim and scope of this work are sufficiently indicated by the title4 ,s4 ,d4 ,,humphrey ,,new ,,york1 #aheh4 ,,contents ,,chapter ,i4 ,polishing the ,daguerreotype ,plate--,buffing the ,plate--,coating the ,plate--,exposure of the ,plate in the ,camera--,position ,developing the ,daguerreotype--,exposure to ,mercury--,removing the ,coating--,gilding or fixing the ,image--,coloring ,daguerreotype1 4 4 4 4 4 #ah ,,chapter ,,ii4 ,coloring ,back ,grounds--,transparent ditto--,gilding ,dissolvent--,solution for removing ,specks--,solarized ,impression--,to ,purify ,water--,cleaning ,mercury--,adhesive ,paper--,black ,stain for ,apparatus--,sealing ,wax for ,bottles--,rouge--,rotten ,stone--,potassa ,solution--,hyposulphite ,solution--,substitute for do4--,gilding ,solution--,solution for increasing the ,brilliancy of the ,daguerreotype--,bleaching ,solution2--,cold ,gilding--,neutralizing ,agents--,buff ,dryer--,keeping ,buffs in order--,cleaning ,buckskins--,reflector for taking ,views1 4 4 4 4 #eb ,,chapter ,,iii4 ,bromine and its ,compounds--,iodine and its ,compounds--,chlorine and its ,compounds--,cyanide of ,potassium--,hyposulphite of ,soda--,hyphosulphite of ,gold--,nitric ,acid--,nitro-,muriatic ,acid--,hydrochloric ,acid--,hydrofluoric ,acid--,sulphuric ,acid--,accelerating ,substances--,liquid ,sensitives--,dry ,sensitives1 etc41 etc41 4 4 4 4 4 #gb ,,chapter ,,iv4 ,light--,optics--,solar ,spectrum--,decomposition of ,light--,light1 ,heat1 and ,actinism--,blue ,paper and ,color for the ,walls of the ,operating ,room--,proportions of ,light1 ,heat and ,actinism composing a ,sunbeam--,refraction--,reflection--,len ses--,copying ,spherical ,aberration--,chromatic ,aberration1 4 4 4 #aca ,,chapter ,v4 ,to make ,plates for the ,daguerreotype--,determining the ,time of ,exposure in the ,camera--,instantaneous ,process for ,producing ,daguerreotype--,galvanizing the ,daguerreotype ,plate--,silvering ,solution--,daguerreotype without ,mercury--,management of ,chemicals--,hints and ,cautions--,electrotyping--,crayon ,daguerreotypes--,illuminated ,daguerreotypes--,natural ,colors in ,heliography--,multiplying ,daguerreotypes on one ,plate--,deposit in ,gilding--,practical ,hints on the ,daguerreotype1 4 4 4 #adi ,,chapter ,,vi4 ,an ,account of ,wolcott and ,johnson's ,early experiments in the ,daguerreotype1 4 4 4 #ahh ,,american ,,hand-,,book of ,,the ,,daguerreotype4 ,,chapter ,i4 ,polishing the ,daguerreotype ,plate--,buffing the ,plate--,coating the ,plate--,exposure of the ,plate in the ,camera--,position--,developing the ,daguerreotype--,exposure to ,mercury--,removing the ,coating--,gilding or fixing the ,image--,coloring ,daguerreotype4 ,polishing the ,daguerreotype ,plate4--,i shall endeavor to present to the reader the process ,i have found productive of good and satisfactory results1 presenting the same in a clear and concise manner1 so that any one1 by following the various manipulations given1 will be enabled to succeed4 ,if there is any one part of the process in ,daguerreotype in which operators fail more than all others1 it is in not properly preparing the plate4 ,it has truly been said that it would take a volume to describe all the methods that have been suggested for polishing the plate4 ,i shall confine myself to the following description1 which has been successfully practised1 also most generally adopted by our operators1 and ,i believe equal1 if not superior to any other method1 yet at the same time it is not of so much importance what particular method is employed1 so that it be thoroughly and skillfully carried out4 ,there is a general tendency with beginners to slight this operation2 hence the necessity of adopting a system which precludes the possibility of doing so4 ,during many years' study and practice in the art1 ,i have tried numerous methods and substances for the better accomplishment of the end in view1 and have finally settled upon the following1 as being 7so far as experience allows me to ,judge7 the modus operandi1 best suited to all circumstances2 under no condition would ,i approve of a method less rigorous or precise4 ,the operator being provided with a bottle of finely prepared rotten stone1 cover the mouth of the bottle with a piece of thick paper1 this perforated with a pin so that the rotten stone can be dusted on the plate4 ,fasten the plate on the holder1 take the rotten stone 7,becker's can always be depended upon71 and dust on lightly until the surface is freely covered2 now drop on the plate's surface a few drops of an alcoholic solution4#a #a ,this solution is composed of equal parts of alcohol and water1 for the summer1 and in winter three parts alcohol to one of water2 a few drops of potassa solution may be added1 and is known to have a decided effect upon the plate4 ,take a patch of ,canton flannel2 in order to prevent the moisture from the hand it should have a thick1 firm texture3 with this rub the plate in circles across1 then back covering one-half of the former row of circles in each crossing until you have gone over the plate and back to the point of beginning1 occupying at least half a minute in the operation1 for a small plate1 and so in proportion for the other sizes4 ,care should be observed to keep the patch wet with the alcoholic solution forming a paste on the surface of the plate2 the motion of the hand should be brisk and free1 not hurried1 and the pressure about equal to that of a pound weight4 ,when the cotton is disposed to adhere to the plate1 and slip from under the finger1 spread the fore and middle fingers a little apart1 then pressing down1 bring them together in such a manner as to form a fold in the cloth between them1 by which means you will hold it perfectly secure4 ,avoid wetting the fingers1 and should they perspire1 wipe them often1 as the moisture penetrating the cotton and coming in contact with the plate1 would cause streaks it would be difficult to remove4 ,i will here remark that many operators use much more cotton flannel than there is need of4 ,i have found in my experience that a single patch1 about one and half inch square1 will be better for cleaning a number of plates than a new piece for every plate4 ,this is the case for the wet1 and for the dryrubbing two or three pieces will be found to answer4 ,thus with four or five cloths a dozen plates may be prepared4 ,some operators use prepared cotton1 and think it more convenient than the flannel4 ,this may be had prepared free from seeds and in a very perfect state1 if wished4 ,in going over the plate1 great care should be observed1 in touching its surface as equally as possible4 ,the greatest care should be taken neither to touch the plate with the fingers1 nor that part of the cotton flannel which is to come in contact with its surface2 take a clean piece of flannel by one corner1 snap it smartly to free it from dust and loose fibres1 lay it face-side upward1 dust on a little fine rotten stone2 with this1 polish around1 or across1 or in circles1 lightly and briskly1 passing gradually over the whole surface of the plate1 as was done before with the wet4 ,the plate should now exhibit a bright1 clear1 uniform surface1 with a strong metallic lustre1 perfectly free from any appearance of film2 if not1 the last polished should be continued until the effect is obtained1 and when once obtained1 the plate is ready for buffing4 ,buffing the ,plate4--,there are a variety of ways and means employed in this part of the operation4 ,some choose wheels1 and others prefer the ordinary hand-buff4 ,i have been unable to detect any peculiar advantage in the use of the wheel except in the facility of the operation2 no doubt1 however1 but there is a saving of time1 particularly in the preparation of the larger plates4 ,for general use1 we have not seen a wheel better adapted for this purpose than the one patented by ,messrs4 ,lewis4 ,it is generally well to use a hand-buff before placing the plate on the wheel2 this is in order to prevent1 as far as possible1 the dust or other substance that may be on the surface of the plate from coming in contact with the cover of the wheel4 ,i will here follow out the use of the hand-buffs 7two are necessary7 as they are mostly used4 ,in the morning1 before using the buffs1 brush both as clean as possible1 in order to free them from dust2 then with the blade of a pair of shears1 held perpendicular1 rub the buffs from end to end2 then knock them both together in order to free them from all dust or other substances1 occasionally exposing them to the sun or to the fire4 ,with one of the buffs 7reserving the finest and softest for the last operation71 powder its face with fine rouge and brush off slightly1 leaving only the finest particles in it4 ,every operator should have two plate-holders2 one for cleaning and one for buffing the plate2 for when using only one1 the rotten stone is liable to get on the buff and scratch the plate4 ,rest the fingers of the left hand on the back of the buff1 near the farther end1 with about the same pressure as in cleaning1 while with the right you bear on the handle to correspond1 and give the buff a free1 easy1 horizontal motion1 passing it very nearly the whole length over the plate each time4 ,continue this operation in such a manner that the plate will on all parts of its surface have received an equal amount of polish4 ,this buff once well filled with polish1 add but little after1 say a small quantity once in two or three plates4 ,the polish as well as the buffs must be kept perfectly dry4 ,the second buff should always be in the best order1 and if this is the case1 but little polish after the first need be used4 ,much depends upon the last finish of the surface of the plate1 and as a fine impression is desired in the same ratio1 the operator must exercise care and skill in this operation4 ,some buff the smaller plates on the hands1 by resting them on the fingers in such a manner that the buff cannot touch them2 some by holding the edges with thumb and little finger1 with the remaining fingers under1 or on the back2 and others buff on the holder4 ,when this last method is adopted1 it requires the greatest caution to prevent the dust from getting on the buff4 ,the holder should be wiped clean4 ,the plate frequently slips off or around1 and the buff comes in contact with the bed of the holder4 ,when1 however1 the operator is so unfortunate as to meet with this mishap1 the utmost care must be observed in thoroughly cleaning the buff cover before further buffing4 ,in this last buffing it may be continued as before1 except without the application of polish powder to the last buff4 ,examine the surface occasionally1 and buff more lightly towards the close of the operation1 using at last the mere weight of the buff4 ,this last buffing should occupy as long a time as the first4 ,the point to be aimed at is1 the production of a surface of such exquisite polish as to be itself invisible1 like the surface of a mirror4 ,the secret of producing pictures discernible in any light1 lies in this3 the more dark1 deep and mirror-like the surface of the plate1 the more nearly do we approach to perfection4 ,in all cases1 very light and long continued buffing is productive of the greater success1 since by that means a more perfect polish can be obtained4 ,the question is often asked1 why is it that the plates receive the coating so unevenly8 ,i will answer by saying that it may arise from two causes3 the first and most general cause is that those parts of the plate's surface which will receive the heaviest coating have been more thoroughly polished1 and the consequence is that it is more sensitive to the chemical operation2 second1 and might perhaps be considered a part of the first1 the heat of the plate may not be equal in all its parts2 this may arise from the heat caused by the friction in buffing4 ,it is a well known fact1 with which every observing practitioner is familiar1 that a silver plate at a temperature of #de deg4 or less1 exposed to the vapors of iodine1 is less sensitive and takes a longer time to coat1 than when it is at a temperature of #fj deg4 or more4 ,whenever a view is to be taken1 or any impression which requires the plate to be turned on the side1 it should be buffed in the other direction1 so that the marks will always be horizontal1 when the picture is in position4 ,with the finest possible polish1 the plate is ready for the coating box4 ,the question is often asked by operators1 what is the state of the plate when polished and allowed to stand for a time before using8 ,to meet this point we hare only to consider the silver and the power acting upon it4 ,pure atmosphere does not act upon silver2 but we do not have this about in our operating rooms1 as it is more or less charged with sulphurated hydrogen1 which soon tarnishes the surface of the plate with a film of brown sulphurate4 ,it is this that sometimes causes the specks which appear on finishing the impression1 and are a great annoyance4 ,hence we see that the plate should be buffed just before receiving the vapor of iodine4 ,mr ,hunt gives his opinion of the use of diluted nitric acid as the best solution for freeing1 the surface of the plate2 he says3 8,numerous experiments on plated copper1 pure silver plates1 and on silvered glass and paper1 have convinced me that the first operation of polishing with nitric acid1 etc41 is essential to the production of the most sensitive surface4 ,all who will take the trouble to examine the subject1 will soon be convinced that the acid softens the silver1 bringing it to a state in which it is extremely susceptible of being either oxydized or iodized1 according as the circumstances may occur of its exposure to the atmosphere or the iodine40 ,i cannot see the objection to this solution2 not1 however1 in general use4 ,our operators do not find it of sufficient importance to the success of their pictures to accept it1 the alcoholic solution being in its nature less objectionable4 ,i will say here1 that a plate submitted to only an ordinary polish is found to contain numberless minute particles of the powder made use of4 ,should the same plate be buffed for a long time1 the polish will nearly all disappear1 leaving the cavities in the surface free for the action of agents employed in subsequent operation4 ,for this reason1 ,i find that great amount of polishing powder should not be applied to the last buff1 and it is obvious that three buffs can be employed to adventure2 the two last should not receive any polishing materials4 ,i have examined a plate that was considered to possess a fine finish1 and similar had produced good impressions2 these same plates1 when subjected to a long and light buffing1 would present a surface no finer in appearance to the naked eye2 but upon exposure to the solar radiation1 would produce a well-defined image in one fourth less time than the plate without the extra buffing4 ,coating the ,plate4--,for this purpose our mechanics and artists have provided a simple apparatus called a coating-box1 which is so arranged as to be perfectly tight1 retaining the vapor of the iodine or accelerators1 and at the same time allowing1 by means of a slide1 the exposure of the plate to these vapors4 ,they can readily be obtained by application to any dealer1 all of whom can furnish them4 ,the principal difficulty in coating the plate1 is that of preserving the exact proportion between the quantity of iodine and bromine1 or quick4 ,it is here necessary to say1 that hardly any two persons see alike the same degree of color1 so as to be enabled to judge correctly the exact tint1 i4 e4 what one might describe as light rose red1 might appear to another as bright or cherry red2 consequently1 the only rule for the student in ,daguerreotype1 is to study what appears to him to be the particular tint or shade required to aid him to produce the desired result4 ,practise has proved that but a slight variation in the chemical coating1 of the ,daguerreotype plate will very materially affect the final result4 ,the operator will proportion the coating of iodine and bromine or accelerators according to the strength and composition of the latter4 ,experience proves that the common impressions1 iodized to a rather light yellow gold tint1 and brought by the bromine to a very light1 rose color1 have their whites very intense1 and their deep shades very black4 ,it is also known that if you employ a thicker coating of iodine and apply upon it a proportionate tint of bromine1 so as to obtain a deep rose tint1 delineations will be less marked1 and the image have a softer tone4 ,this effect has been obvious to everyone who has practised the art4 ,thus ,i may observe that the light coatings produce strong contrast of light and shade1 and that this contrast grows gradually less1 until in the very heavy coating it almost wholly disappears4 ,from this it will readily be perceived that the middle shades are the ones to be desired for representing the harmonious blending of the lights and shades4 ,then1 if we examine1 with respect to strength1 or depth of tone1 and sharpness of impression1 we see that the light coating1 produces a very sharp but shallow impression2 while the other extreme gives a deep but very dull one4 ,here1 then1 are still better reasons for avoiding either extreme4 ,the changes through which the plate passes in coating may be considered a yellow straw color or dark orange yellow1 a rose color more or less dark in tint1 or red violet1 steel blue or indigo1 and lastly green4 ,after attaining this latter color1 the plate resumes a light yellow tint1 and continues to pass successively a second time1 with very few exceptions1 through all the shades above mentioned4 ,i will here present some excellent remarks upon this subject by ,mr4 ,finley4 ,this gentleman says3 8,it is well known to all who have given much attention to the subject1 that an excess of iodine gives the light portions of objects with peculiar strength and clearness1 while the darker parts are retarded1 as it were1 and not brought out by that length of exposure which suffices for the former4 ,hence1 statuary1 monuments1 and all objects of like character1 were remarkably well delineated by the original process of ,daguerre2 the plate being coated with iodine alone4 ,an excess of bromine1 to a certain degree1 has the opposite effect2 the white portions of the impression appearing of a dull1 leaden hue1 while those which should be black1 or dark1 appear quite light4 ,this being the case1 ,i conclude there must be a point between the two extremes where light and dark objects will be in photogenic equilibrium4 ,the great object1 therefore1 is to maintain1 as nearly as possible1 a perfect balance between the two elements entering into union to form the sensitive coating of the plate1 in order that the lights and shades be truly and faithfully represented1 and that all objects1 whether light or dark1 be made to appear so far conformable to nature1 as is consistent with the difference in the photogenic energy of the different colored rays of light4 ,it is this nicely-balanced combination which ensures1 in the highest degree1 a union of the essential qualities of a fine ,daguerreotype1 viz41 clearness and strength1 with softness and purity of tone4 8,so far as ,i know1 it is the universal practice of operators to judge of the proportion of iodine and bromine in coating the plate1 by two standards of color the one fixed upon for the iodine1 the other for the additional coating of bromine4 ,now ,i maintain that these alone form a very fallacious standard2 first1 because the color appears to the eye either lighter or darker1 according as there is more or less light by which we inspect the coating2 and secondly1 because if it occur that we are deceived in obtaining the exact tint for the first coating1 we are worse misled in obtaining the second1 for if the iodine coating be too light1 then an undue proportion of bromine is used in order to bring it to the second standard1 and vice versa40 ,the iodine box should be kept clean and dry4 ,the plate immediately after the last buffing1 should be placed over the iodine1 and the coating will depend upon the character of the tone of the impression desired4 ,coating over dry iodine to an orange color1 then over the accelerator1 to a light rose1 and back over iodine one sixth as long as first coating1 will produce a fine1 soft tone1 and is the coating generally used for most accelerators4 ,the plate iodized to a dark orange yellow1 or tinged slightly with incipient rose color1 coated over the accelerator to a deep rose red1 then back over iodine one-tenth as long as at first coating1 gives a clear1 strong1 bold1 deep impression4 ,i will here state a singular fact1 which is not generally known to the operator4 ,if a plate1 coated over the iodine to a rose red1 and then exposed to strong dry quick or weak bromine water1 so that a change of color can be seen1 then recoated over the iodine twice as long as at first coating1 it will be found far more sensitive when exposed to the light than when it has been recoated over the iodine one-fourth of the time of the first coating4 ,probably the best accelerating combination is the ,american compound formerly known as 8,gurney's ,american compound10 or some of the combinations of bromide of lime4 ,the first is thought to possess perhaps more uniformity in its action than any other combination ,i have ever used4 ,the plate once coated should be kept excluded from the light by means of the plate holder for the camera box4 ,i will notice one of the principal causes having a tendency to prevent the perfect uniformity of chemical action1 between the iodine and silver2 hydrogen1 or the moisture in the atmosphere1 makes a very perceptible barrier4 ,this moisture may arise as the result of the cold1 from a want of friction in the buffing of the plate1 which1 coming in contact with the warmer air1 as a writer on this subject says3 8,it is well known that as often as bodies1 when cold1 are exposed to a warmer air1 the humidity contained in them is condensed4 ,it is to this effect that we must attribute the difficulty experienced in operating in most cases40 ,this is corroborated by the results experienced by our operators4 ,so it is seen that the plate should be of a temperature above that of the atmosphere4 ,mr4 ,gurney submits his plates to a gentle heat from a spirit lamp just before exposing them to the vapor of iodine4 ,experience has convinced me that a plate heated to about #hj deg4 before being exposed to iodine will present a far better defined image than a plate at a temperature of #ej deg4 ,i account for this by noticing that1 at a higher temperature1 the plate throws off any larger crystals that might otherwise be deposited1 receiving only the finer1 thus producing a more perfect chemical combination of iodide of silver4 ,i would call the attention of the operator to this point1 as presenting something of interest1 and which may direct in a way of accelerating the future operations4 ,that the presence of a film of moisture over the plate is a preventive of uniform chemical action1 may be readily understood from the fact that iodine is almost insoluble in water1 requiring seven thousand parts of water to dissolve one of iodine1 or one grain to a gallon of water4 ,yet its affinities for silver and other substances are so powerful as to prevent its existing in an insulated state1 hence we can account for the frequent occurrence of a plate presenting parts of an image over its surface4 ,it is quite evident that those parts of plate's surface covered with moisture are nothing like as sensitive to the iodine as those parts perfectly free4 ,exposure of the plate in the ,camera1 and ,position4--,the time of exposure necessary to produce an image upon the ,daguerreotype plate1 can only be determined by experiment1 and requires a liberality of judgment to be exercised on the part of the operator4 ,the constant variation of the light renders it impossible to lay down any exact rule upon this point4 ,light is not alone to be considered2 the amount of coating exercises a deviating influence1 also the subjects to be represented are not equally photogenic1 some requiring much longer time of exposure than others4 ,this may be easily observed by exposing the plate at the same time to a plaster bust and a piece of black velvet1 the first being a much stronger reflector of light than the latter3 the time necessary to produce a well developed image of the velvet being about six times longer than that required to produce an equally defined image of plaster4 ,the manner of judging correctly of the time is by the appearance of impression after it has been developed by the mercurial vapors4 ,should it present a deep blue or black appearance it is solarized or over-timed4 ,this sometimes is to an extent1 that a perfect negative is formed1 the white being represented black1 and the dark light4 ,an object requiring the particular care and attention of the operator is the proper focus4 ,it is not unfrequently the complaint of sitters that their hands are represented as being magnified and greatly out of proportion with the general figure4 ,this is the case also with the nose and eyes1 but in a less degree4 ,as this cannot be wholly remedied1 it is desirous to come as near as possible1 and in order to do this1 it is necessary to present the figure in such a position as to bring it as nearly as possible upon the same plane by making all parts nearly at equal distance from the lenses4 ,this must be done by the sitter inclining the head and bust formed to a natural1 easy position1 and placing the hands closely to the body1 thus preserving a propel proportion1 and giving a lively familiarity to the general impression4 ,it is not an uncommon fault among our less experienced operators to give a front view of the face of nearly every individual1 regardless of any particular form1 and this is often insisted upon by the sitter1#b who seems to think the truth of the picture exists principally in the eyes staring the beholder full in the face4 #b ,i might here picture some curious scenes experienced by our operators ,every one is familiar with a certain class of our community whose ideas of the importance of a free and easy position of the body are too closely confined with stays1 attention to toilet1 tightly fitting dress coats and the like1 to admit of being represented as if nature had endowed them with least possible power of flexibility4 ,to such we would suggest the following1 to be well learned and retained in the mind while presenting themselves before the ,daguerreotype camera3 8,the experience of one who has often been ,daguerreotyped1 is1 to let the operator have his own way40 ,nothing1 in many instances1 can be more out of place in a ,daguerreotype portrait than this1 for let a man with a thin1 long1 defeated-politician-face1 be represented by a directly front view1 we have1 to all appearances1 increased the width of the face to such an extent as to reveal it flat and broad1 losing the characteristic point by which it would be the most readily recognized4 ,the method we should adopt in taking the likeness of such an individual as above1 would be to turn the face from the camera1 so as to present the end of the nose and the prominence of the cheek bone equally distant from the lenses1 and then focusing on the corner of the eye towards the nose1 we cannot in many cases1 fail to produce an image with the lips1 chin1 hair1 eyes and forehead in the minutest possible definition4 ,it should be the study of every operator to notice the effect of the lights and shades while arranging the sitter1 and at the same time be very particular to give ease in the position4 ,no matter how successful the chemical effect may have been1 should the image appear stiff and monument-like1 all is lost4 8,in the masterpiece1 grace and elegance must be combined40 ,i will here use the words of another1 which are very true3 8,so great is the difference in many faces1 when inspected in opposite directions1 that one of the two views1 however accurately taken1 would not communicate the likeness--it not being1 the usually observed characteristic form4 ,when the right view of the head is obtained1 it is first necessary to consider the size of the plate it is to be taken on1 so as to form an idea of the proportion the head should bear to it4 ,the mind must arrange these points before we commence1 or we shall find everything1 too large or too small for the happy proportion of the picture1 and the conveying of a just notion of the stature4 ,the work will have to be done over1 and time sacrificed1 if this is not attended to4 ,the adjustment of the head to the size of the plate 7as seen from the margin of the mat71 is not to be taught3 everyone must bring himself1 by scrutinizing practice1 to mathematical accuracy2 for something will be discovered in every face which can be surmounted only by experience4 8,the eye nearest the camera1 in a three-quarter-face1 is placed in the middle of the breadth of the plate2 the chin1 in a person of middle stature1 in the middle of the length1 and higher according to the proportional height of the person40 ,in regard to the proper elevation of the camera1 it may be here stated that ,i have found it best in taking portraits where the hands are introduced1 to place the camera at about equal height with the eyes of the sitter1 in order to bring the face and hands equi-distant from the tube4 ,it will be found1 if the above be followed1 that by attaching a string to the camera tube1 and making a semi-circle1 that the face and hands of the sitter will occupy a corresponding distance1 and the consequence is that the impression will appear without the hands being magnified4 ,it has been found that a person with a freckly face can have as fine1 fair1 and clear an impression as the most perfect complexion2 this may be done by the subject rubbing the face until it is very red4 ,the effect is to lessen the contrast1 by giving the freckles and skin the same color and the photogenic intensity of the red and yellow being nearly the same1 an impression can be produced perfectly clear4 ,when a child is to be taken1 and there are doubts of its keeping still1 the operation may be accelerated by placing it nearer the window bringing the screen nearer1 and placing a white muslin cloth over the head2 this will enable you to work in one third of the usual time4 ,should the person move1 or the plate become exposed to the light1 it may be restored to its original sensitiveness by placing it over the quick1 one or two seconds4 ,developing the ,daguerreotype4--,after the plate has been submitted to the operation of the light1 the image is still invisible4 ,it requires to be exposed to the vapors of heated mercury4 ,it is not absolutely necessary to apply artificial heat to the mercury to develop the image1 for fair proofs have been produced by placing a plate over the bath at the ordinary temperature of the atmosphere4 ,this plan1 however1 requires a long time and cannot be adopted in practice1 even if it were advisable4 ,the time more usually required in developing the image over the mercurial vapors1 is about two minutes1 and the temperature is raised to a point necessary to produce the desired effect in that time4 ,this point varies as indicated by different scales1 but for the ordinary scales it is not far from #ij deg4 cen4 ,the mercury bath is accompanied with a centigrade thermometer1 by which the heat is regulated4 ,those furnished by the manufacturers are not always correct1 and it requires some experience to find the proper degree on the scale4 ,i would here remark that it is advisable1 when placing the spirit lamp under the bath1 to so arrange it that the position of applied heat should always be on the same point1 viz41 should the heat be directly under the bulb containing the thermometer it would raise the mercury in the tube to the point marked1 and the temperature of that in the bath would be far below what it should be2 hence it is 7where time is followed for developing7 that many failures occur4 ,this is observed more readily in the large baths made of thick iron1 particularly upon first heating4 ,in practice ,i apply the heat as nearly as possible between the centre of the bottom of the bath and the bulb containing the mercury tube4 ,it is advisable to keep the lamp lighted under the bath from the time of commencing in the morning to the close of business at night4 ,by this means you have a uniformity of action1 that cannot be otherwise obtained4 ,it is well known to the experienced ,daguerreotypist1 that different atmospheres have a decided effect upon the mercury in developing the ,daguerreotype4 ,it will require a greater degree of heat for one atmosphere than for another4 ,experience alone determines this little difference4 ,in summer1 on cloudy and stormy days1 mercurial vapors rise more readily and quickly than in the temperature of autumn or winter4 ,from #fj degrees upwards towards the boiling point 7#ffj deg471 the vapors of mercury rise in greater abundance and collect in larger globules on cold surfaces4 ,for various reasons ,i prefer a high temperature and short exposure4 ,it accelerates the process4 ,it renders the lights of the picture more strong and clear1 while the deep shades are more intense4 ,it gives a finer lustre to the drapery4 ,the solarized portions also are very seldom blue1 especially after gilding4 ,if heated too high1 however1 the light parts become of a dead1 chalky white1 and the shadows are injured by numerous little globules of mercury deposited over them4 ,just the right quantity of mercury leaves the impression of a transparent1 pearly white tone1 which improves in the highest degree in gilding4 ,to mercurialize with exactness is a nice point4 ,if there is reason to suspect having timed rather short in the camera1 reduce the time over mercury in a corresponding proportion4 ,a dark impression will be ruined by the quantity of mercury which would only improve a light one4 ,if practicable1 it is most expedient that the plate be submitted to the action of mercury immediately on coming from the camera4 ,i have frequently1 however1 carried plates for miles in the plate-holders and after exposing in the camera1 brought them back to expose to mercury1 and obtained fair proofs2 but for the reason before given1 it is advisable to carry along the bath1 and bring out the impression on the spot4 ,it is sometimes the practice of inexperienced operators to take the plate off the bath and examine the impression by solar light4 ,this plan should be abandoned1 as it is almost sure to produce a dense blue film over the shadows4 ,this ,i am led to believe is occasioned by the action of light on the yet sensitive portions of the plate1 and made to appear only by subsequent exposure to mercury1 being equivalent to solarization4 ,there has been little said by our professors upon the subject of the position of the plates while exposed to the mercurial vapour4 ,mr4 ,hunt1 in referring to this subject1 says3 8,daguerre himself laid much stress upon the necessity of exposing the plate to the mercury at an angle of about #de deg44 ,this1 perhaps1 is the most convenient position as it enables the operator to view the plate distinctly1 and watch the development of the design2 but beyond this1 ,i am satisfied there exists no real necessity for angular position4 ,both horizontally and vertically1 ,i have often produced equally effective ,daguerreotypes40 ,i presume from the last sentence of ,mr4 ,hunt1 that he has confined his experiments to the smaller sized plates4 ,hence he may not have thought of the effect of the vertical exposure of a large plate4 ,in ,america this is a subject of no little importance4 ,when an impression is to be developed upon a plate fifteen by seventeen inches1 were we to use an angle of about #de deg41 it would be found to make a perceptible difference in the appearance of the image4 ,by examining the wood tops of our baths as formerly made1 it will be found that there is a great variation in the distance from the mercury to the different portions of the plate4 ,by measuring one of these tops for the size plate above mentioned1 ,i find the distance to the nearest point between the mercury and the plate1 to be thirteen1 and the middle point sixteen1 and the furthest point twenty-one and a half inches3 by this we see that one point of the plate is eight and a half inches further from the mercury than the nearest point2 even this is not the variation there would necessarily be1 were we to adopt the angle of #de deg4 as urged by ,daguerre4 ,among our principal professors1 the bevel top will not be found in use where the large plates are used4 ,should any one feel desirous to test more minutely the effect produced by a bevel top bath1 ,i would suggest to them to place a frame1 so constructed as to hold three sixth size plates1 and fit it to the top of the bath1 and so arrange it with openings that the plates may be placed1 one at the nearest point of the mercury1 the second midway1 and the third to the greatest distance1 and by placing the plates over at one and the same time1 the experimenter will be enabled to judge if there exists a difference in the developing4 ,in speaking of the above1 reference is had to baths to the ordinary heights used by operators4 ,we will now proceed to examine the effect produced by mercurial vapor upon the plate at different lengths of exposure4 ,in some investigations which ,i have made upon the appearance of the ,daguerreotype impressions when developed over mercury at #ij deg4 ,c4 7#aid deg4 ,f471 the following was the result4 ,plates1 coated and exposed to light in our usual manner of operating1 produced on exposure of #a_/b minute1 whole impression1 deep blue4 #a minute1 ashy and flat2 no shadows2 linen1 deep blue4 #a #a_/b minute1 coarse and spongy2 shadows1 muddy2 drapery1 dirty reddish brown4 #b minutes1 shallow or watery2 shadows1 yellowish2 drapery1 brown4 #b #a_/d minutes1 soft2 face1 scarcely white2 shadows1 neutral2 drapery1 fine dark brown linen somewhat blue4 #b #a_/b minutes1 clear and pearly2 shadows1 clear and positive1 of a purple tint2 drapery1 jet black1 with the dark shades slightly frosted with mercury4 #b #c_/d to #c minutes1 hard and chalky2 shadows1 harsh2 drapery1 roughened1 and misty with excess of mercury4 ,the foregoing results will be found general4 ,there are numerous opinions among our operators in regard to the quantity of mercury necessary for a bath4 ,as regards this1 ,i need only say1 similar results occur when two pounds or two ounces are used1 but the quantity generally employed is about a quarter of a pound4 ,i am of the opinion that one ounce will answer as well as a larger quantity4 ,i know of no better proof in favor of a small quantity than that presented in the following incident4 ,several years since1 an operator 7,mr4 ,senter1 of ,auburn1 ,n4,y47 of my acquaintance1 was requested to go several miles to take a ,daguerreotype portrait of a deceased person4 ,he packed up his apparatus and proceeded over a rough road for some distance to the house where he was to take the portrait1 and arranging his apparatus1 with all the expedition which the occasion required1 after having everything in usual order 7as was supposed71 he proceeded and took some ten or twelve very superior impressions4 ,they were fine1 clear1 and well developed4 ,after taking the number ordered1 he proceeded to repack his apparatus1 and to his surprise1 when he took up the bottle he carried the mercury in1 he found it still filled1 and none in the bath1 except only such particles as had adhered to the sides1 after dusting and being jolted for several miles over the rough road4 ,from this it will be seen that a very little mercury will suffice to develop fine proofs4 ,i saw some of the impressions referred to above1 and they were certainly well developed1 and very superior specimens of our art4 ,removing the ,coating4--,after the impression has been developed over the mercurial vapor1 the next step is to remove the sensitive coating4 ,for this purpose the following solution is used3 ,put about two ounces of hyposulphite of soda in a pint of water1 which should always be filtered before using4 ,a convenient way of doing this is to have two bottles1 and a large funnel with a sponge pressed into the neck of it2 or1 what is better1 some filtering paper folded in it4 ,the solution in one bottle1 the funnel is placed in the other1 and the picture held over it2 when the solution is poured on the plate1 it runs from it into the filter1 and is always ready for use4 ,it is best that the washing be done immediately on the plate coming from the mercury bath4 ,if allowed to stand long with the coating on1 it assumes a very dark tint--as the operation of the light continues1 though less active than while exposed in the camera1 and destroys that brightness which would otherwise have been obtained4 ,it is preferable to wash and gild a picture without it first being dried2 yet when there are doubts of its giving satisfaction1 there would sometimes be a saving by drying and getting the decision of the subject before gilding1 as this last injures the plate for another impression4 ,first1 light your spirit-lamp1 then with your plyers take the plate by the lower right-hand corner1 holding it in such a manner that the plyers will form in a line with the upper left-hand corner2 pour on1 slowly1 the hyposulphite solution1 slightly agitating the plate1 until all the coating is dissolved off2 then rinse off with clean water1 and if it is not to be gilded1 dry by holding the plate perpendicular with the bottom left-hand corner lowest1 and applying the blaze of the spirit-lamp to the back1 at the same time blowing gently downward on the face of the plate4 ,the hyposulphite solution should be often filtered through a sponge1 and it will answer for a great number of washings4 ,yet it is observed that the mercury collects in this solution in small globules2 these often come in contact with the plate1 causing white spots1 which spoil the impression4 ,they should be guarded against1 and the solution renewed4 ,again1 in order to prevent streaks or scum on the surface of the plate1 it is necessary that the coating should be removed with a good degree of uniformity4 ,i find in practice that the hyposulphite of soda in our market varies much as regards strength1 and consequently the rule to be adopted is to make a solution of sufficient strength to remove the coating in about ten seconds4 ,i am aware that it may be said that this strong solution would have a tendency to injure the impression by destroying in a measure the sharpness of outline4 ,to meet this1 it need only to be said that the preventive is1 to not let the solution rest on the surface of the plate for a longer time than is absolutely necessary1 and then it should be drenched copiously with water2 hence a chemical action upon the image is prevented and the general operation facilitated4 ,this plan is adopted by our first operators with the greatest success4 ,if the operator should allow the hyposulphite solution to run over the plate unevenly1 it is quite likely that white or blue streaks would result4 ,these it is impossible to remove without injury to the impression4 ,some1 in order to prevent this1 breathe over the surface1 thus moistening it and putting it in a condition to receive the solution with greater uniformity4 ,the plate should be well washed with water before gilding4 ,gilding1 or ,fixing the ,image4--,the next process to be given is that for fixing the image on the plate4 ,this is done by precipitating a thin film of gold over the surface and is productive of the most brilliant effect when prepared immediately after the plate has been washed with water after the application of the hyposulphite solution1 and before the plate has been allowed to dry4 ,when1 however1 the plate has been dried and allowed to stand for any time1 before gilding1 the hyposulphite wash should be applied as at first1 in order to destroy any chemical coating that may have been formed on exposure of the plate to the air4 ,for gilding the larger plates1 we have a gilding stand so constructed that the plate can be put on a perfect level4 ,in practice1 ,i prefer holding the plate with nippers1 fastened at one corner4 ,hold the plate in the same manner as in removing the coating2 pour on the gilding1 newly filtered1 until the surface is wholly covered1 and with the blaze of the spirit lamp1 at least three inches high1 apply it to the back of the plate1 moving it about1 that the surface may be heated with as much uniformity as possible4 ,continuing this operation1 the surface will generally become covered with small yellow bubbles which soon disappear1 leaving the image clear and distinct4 ,it is advisable to make use of a lamp having a sufficiently strong flame to produce the effect in a few minutes4 ,if after a first heating1 it is found that the impression can admit of a greater degree of intensity1 it might be heated anew2 but that is seldom necessary1 and often by trying to do too1 well1 the operator1 if he persists in heating certain parts of the plate1 may find the liquid dry up just above the flame1 and inevitably cause a stain2 #c or else the blacks are covered with a film1 or even the coating of gold may suddenly exfoliate1 when small particles are detached from the plate4 ,the impression is then entirely spoiled1 but the plate may be re-polished4 #c ,this can be remedied1 however1 if it is immediately washed over with the same solution that is on the plate1 so that the surface shall not become cool2 continue for a short time to apply the lamp under1 and agitate the plate slightly1 and it will soon be free from all imperfections and give a fine clear tone4 ,it is not unfrequent that the surface assumes a dark1 cloudy appearance4 ,this is generally the best sign that the gilding will bring out the impression with the greatest degree of distinctness4 ,soon1 the clouds gradually begin to disappear1 and1 8like a thing of life0 stands forth the image1 clothed with all the brilliancy and clearness that the combined efforts of nature and art can produce4 ,when in the operator's judgment the operation has arrived at the highest state of perfection1 rinse suddenly1 with an abundance of clean water1 and dry as before described4 ,when an impression is dark1 the gilding process may be longer continued2 but when light1 it should be gilded quickly1 as lengthening the time tends to bleach the impression and make it too white4 ,the cause of this appears to be1 that with a moderate heat the chlorine is merely set free from the gold1 and remaining in the solution1 instead of being driven off1 with its powerful bleaching1 properties1 it immediately acts upon the shades of the picture4 ,a dark impression can thus1 by a low heat1 long-continued1 be made quite light4 ,to procure the best effect1 then1 heat suddenly with a large blaze1 and judging it to be at the maximum1 cool as suddenly as possible4 ,when the hyposulphite of gold is used instead of the chloride1 a less heat should be employed4 ,coloring ,daguerreotypes4--,of all the so-called improvements in the ,daguerreotype1 the coloring is the least worthy of notice4 ,yet the operator is often1 in fact most generally1 called upon to hide an excellent specimen under paint4 ,i can conceive of nothing more perfect in a ,daguerreotype than a finely-developed image1 with clearness of lights and shadows1 possessing the lively tone resulting from good gilding4 ,such pictures1 however1 are not always had1 and then color may perform the part of hiding the imperfections4 ,we present the following method as given in ,willat's ,manual3 8,daguerreotype portraits are now commonly met with beautifully colored2 but the coloring is a process requiring great care and judgment1 and many good pictures are spoiled in fruitless experiments4 ,several different methods of coloring have been proposed4 ,the simplest mode appears to be that of using dry colors prepared in the following manner3 ,a little of the color required1 very finely ground1 is thrown into a glass containing water1 in which a few grains of gum arabic have been dissolved4 ,after standing a few moments1 the mixture may be passed through bibulous paper1 and the residue perfectly dried for use4 ,the principal colors used are ,carmine1 ,chrome ,yellow1 ,burnt ,sienna1 ,ultramarine and ,white2 boxes fitted with sets of colors properly prepared1 may be obtained of the dealers1 and include ,carmine1 ,white1 ,lilac1 ,sky ,blue1 ,pink1 ,yellow1 ,flesh color1 ,orange1 ,brown1 ,purple1 ,light ,green1 ,dark ,green and ,blue4 ,with a few colors1 however1 all the rest may be made thus3 ,orange1 by ,yellow and ,red2 ,purple1 with ,blue and ,red2 ,green1 ,blue and ,yellow2 ,brown1 with ,umber1 ,carmine and ,lamp ,black2 ,scarlet1 ,carmine and ,light ,red4 ,while it is true that a little color may relieve the dark metallic look of some ,daguerreotypes1 it must not be concealed that the covering of the fine delicate outline and exquisite gradations of tone of a good picture with such a coating1 is barbarous and unartistic4 8,the prevaling taste is1 however1 decidedly for colored proofs1 and the following directions will assist the amateur in ministering to this perverted taste1 should he be so inclined4 ,the coloring should commence with the face1 and the flesh tint must be stippled on 7not rubbed7 with a small camel's-hair brush1 beginning from the centre of the cheek1 taking great care not to go over the outline of the face1 and also not to have too much color in the brush2 the eyes and eyebrows must not be touched with color4 ,after the flesh color is applied1 take a piece of very soft cotton and pass it very gently backwards and forwards over the face1 so as to soften down the color1 and then apply the carmine to give the required tint4 ,for men1 the darker tints should predominate1 and for women the warmer4 ,very light hair may be improved by a slight tint of brown1 or yellow and brown1 according to the color4 ,in coloring the drapery1 the same care must be used4 ,no rules can be laid down for all the different colors required1 and the amateur had better obtain the assistance or advice of some one accustomed to the use of colors4 ,a little white with a dash of blue or a little silver1 will improve white linen1 lace1 etc4 ,the jewelry may be touched with gold or silver from the shells1 moistened with distilled water1 and laid on with a fine-pointed sable-hair brush4 8,brilliants may be represented by picking the plate with the point of a pin or knife40 ,,chapter ,,ii4 ,,miscellaneous4 ,coloring ,back ,grounds--,transparent ditto--,gilding ,dissolvent ,solution for removing ,specks--,solarized ,impression--,to ,purify ,water--,cleaning ,mercury--,adhesive ,paper--,black ,stain for ,apparatus--,sealing ,wax for ,bottles--,rouge--,rotten ,stone--,potassa ,solution--,hyposulphite ,solution--,substitute for do4--,gilding ,solution--,solution for increasing the ,brilliancy of the ,daguerreotype--,bleaching ,solution2--,cold ,gilding--,neutralizing ,agents--,buff ,dryer--,keeping ,buffs in order--,cleaning ,buckskins--,reflector for taking ,views4 ,to ,color ,back-grounds--,to obtain a properly colored back ground is a matter of no little importance to the ,daguerreotype operator4 ,i had nearly exhausted all patience1 and tried the skill of painters to obtain a back-ground that would be suitable to my purpose2 but all to no avail4 ,at last ,i adopted the following method1 and at a cost of coloring of twenty-five cents1 can now produce a back-ground far more valuable than those which had cost five dollars before4 ,take common earth paint1 such as is used in painting roofs2 mix this with water to about the consistency of cream2 then to four quarts of this mixture add about one pint of glue water 7common glue dissolved in water1 also about as thick as cream74 ,this last will cause the paint to adhere to the cloth1 to which it is applied with a common white-wash brush4 ,by applying the brush on the coating while it is wet1 it may be so blended that not a line can be seen1 and a perfectly smooth color of any shade can be obtained4 ,the shade of color ,i use is a light reddish-brown4 ,tripoli1 rotten-stone1 or any earthy matter1 may be applied in the same manner4 ,transparent or ,invisible ,back-ground4--,i give this as originally published in my ,system of ,photography1 #ahdi3 8,take a large woollen blanket with long nap1 the longer and rougher it is the finer will be the effect produced2 stretch it on a frame of sufficient size1 and suspend the frame at the centre of the upper end by a string fastened to a nail in the ceiling1 from three to five feet back of the sitter4 ,having arranged this1 fasten another string to the side of the frame1 and while the operation is going on in the camera1 swing the back-ground from right to left1 continuing this during the whole time of sitting1 and you have a clear 8transparent0 back-ground1 which throws the image out in bold relief1 and renders the surface of the plate invisible4 ,if equalled at all it is only by atmospheric back-ground4 ,i consider it to be the best ever known1 and think it needs but to be tried to afford satisfactory proof that it is so4 ,although used by few before1 since the first edition of this work at least two thirds of the operators have adopted its use2 for any one can at once understand the principle and the effect which it produces40 ,it may be added that a motion imparted to to any back-ground where softness is desired1 produces an excellent effect4 ,gilding ,dissolvent4--,to one quart of muriatic acid add as much oxide of iron 7common iron rust7 as it will dissolve in two days4 ,this may be done by putting in the oxide in excess4 ,it should be frequently shook1 and when wanted for bottling it should be allowed to stand in order to settle4 ,when this is done the solution may be poured off1 and reduced by adding to it an equal quantity of water2 then it is ready for use4 ,this constitutes a gilding dissolvent now in our market4 ,solution for ,removing ,specks4--,there is probably no one cause of complaint so general as 8what makes those black specks80 ,there are several causes which produce them1 and probably the most general are dust1 rouge1 or a spray of moisture on the plate4 ,it this be the case1 there is no solution which can remove them1 as they have prevented a chemical action with the silver1 and their removal would only expose the surface of the plate which in itself would afford a contrast with the impression4 ,another and less dangerous source of these specks is organic matter contained in the solution employed in dissolving the chemicals1 or the water in washing4 ,much of the hyposulphite of soda in market contains a sulphuret1 which1 coming in contact with the silver surface1 immediately causes oxidation4 ,such spots1 as well also as most all others found on the plate after it has been exposed in the camera1 can be removed by the following1 solution3 ,to one ounce of water add a piece of cyanide of potassium the size of a pea2 filter the solution and apply by pouring it on the surface of the plate4 ,in all cases the plate should first be wet with water4 ,apply a gentle heat1 and soon the spots disappear1 leaving the impression clear and free from all organic matter4 ,in the absence of cyanide of potassium1 a solution of pure hyposulphite of soda will answer as a fair substitute4 ,to ,redeem1 a ,solarized ,impression4--,the ,daguerreotype plate1 prepared in the ordinary manner1 should be exposed in the camera a sufficient time to solarize the impression4 ,then1 before it be exposed to the vapor of mercury1 expose it for a very brief period to the vapor of either chlorine1 bromine or iodine4 ,then expose over mercury1 as usual4 ,i have produced singularly interesting results by this process4 ,to ,purify ,water4--,filter the water well1 and then add about three drops of nitric acid to the pint4 ,this can be used as absolutely pure water1 but ,i would recommend the use of distilled water as preferable4 ,cleaning ,mercury4--,make a small bag of chamois skin1 pour in the mercury1 and squeeze it through the leather4 ,repeat this several times1 and filter by means of a funnel made of paper1 with a very small aperture1 through which it will escape and leave the particles of dust1 or other substances1 in the paper4 ,a paper with a pinhole through it will answer as well1 and it is less difficult to make4 ,adhesive ,paper4--,take gum arabic1 four ounces1 put it in a wide-mouthed bottle and pour on water about one-third above the gum4 ,add half ounce of isinglass1 or fish glue1 and a small piece of loaf sugar4 ,let all dissolve1 and spread over ,french letter paper1 with a brush or piece of sponge4 ,if once spreading is not enough1 perform the same operation a second time4 ,black ,stain for ,apparatus4--,dissolve gum shellac in alcohol1 or procure shellac varnish at the druggists'1 stir in lampblack1 and apply with a sponge or bit of rag4 ,this will adhere to metal1 as well as wood1 and is used for the inside of camera1 tubes1 etc4 ,sealing ,wax for ,bottles4--,melt together six parts rosin and one beeswax1 and add a small quantity of lampblack2 or1 if red is preferable1 add red lead4 ,common white wax is best1 as most chemicals act less upon it4 ,when bottles containing bromine are to be sealed1 it is well to grease the stopper4 ,this1 however1 only when the bottle is in frequent use1 for if it were to be sent by any conveyance it would be likely to fly out4 ,rouge4--,the method employed by ,lord ,ross is probably unsurpassed in the production of rouge4 ,he has given his process as follows3 8,i prepare the peroxide of iron by precipitation with water of ammonia1 from a pure dilute solution of sulphate of iron2 the precipitate is washed1 pressed in a screw press till nearly dry1 and exposed to a heat which in the dark appears a dull1 low red4 ,the only points of importance are1 that the sulphate of iron should be pure1 that the water of ammonia should be decidedly in excess1 and that the heat should not exceed that ,i have described4 ,the color will be a bright crimson inclining to yellow4 ,i have tried both potash and soda1 pure1 instead of water of ammonia1 but after washing with some degree of care1 a trace of the alkali still remained1 and the peroxide was of an ochrey color1 till overheated1 and did not polish properly40 ,care should be observed to apply rouge in a dry state to the surface of the plate4 ,i would remark1 that so far as my experience has gone1 ,i consider good rouge fully equal to any other polishing1 material for the last or finishing polishing2 consequently ,i shall not take up my space in enumerating any of the great variety that find few advocates4 ,why ,rouge is to be preferred4--8,because it burnishes better1 and because it assists in fixing the layer of gold1 rendering it less susceptible of being removed in scales when heated too much40 ,rotten ,stone4--8,purchase the best ground rotten stone of the druggist1 put a few ounces at a time in a wedgewood or porcelain mortar1 with plenty of clean rain water4 ,this should have about forty drops of nitric acid to the quart4 ,grind well1 and after letting the mortar stand two minutes1 pour into a third4 ,after remaining undisturbed eight minutes1 finally pour off into a fourth to settle4 ,rinse back the sediment in the second and third1 and grind over with a new batch4 ,repeat the operation till you have all in the fourth vessel4 ,let this stand several hours1 and pour off the water very carefully4 ,set the deposit in the sun1 or by a stove to dry4 ,when perfectly dry1 pulverize1 and it is ready for use4 ,with a little trouble you will obtain in this way a much better article than can generally be bought of dealers4 ,for the last washing1 alcohol1 or a mixture of alcohol and water1 is preferable40 ,potassa ,solution4--,the use of a solution of potassa in the preparation of the plate was suggested in the early history of the ,daguerreotype4 ,it was thought to possess some peculiar property for improving the tone of the impression4 ,it is used for moistening the rotten stone in polishing the plate1 and may be prepared by putting about an ounce and a half of alcohol in a close bottle1 and add half a stick of caustic potash4 ,this will soon become of a deep red color4 ,for use1 fill your small bottle1 having a quill in the cork1 with alcohol1 and add a few drops of the above1 or enough to change it to a bright orange or saffron color4 ,a ,substitute for the ,hyposulphite ,solution4--,m4 ,,daguerre recommends the use of a solution of salt water for removing the coating off the plate4 ,i found this of some service at one time during my travels4 ,my hyposulphite bottle got broke and its contents lost1 so as only to leave enough for preparing gilding4 ,i resorted to the use of salt solution1 and found it to answer well4 ,make a saturated solution of salt in water4 ,first wash the plate with clear water2 then immerse it in the saline solution1 when it should be agitated1 and the coating will soon disappear4 ,another process with a salt solution of half the strength of the above is very interesting and effectual4 ,the plate having been dipped into cold water1 is placed in a solution of common salt1 of moderate strength2 it lies without being acted upon at all2 but if it be now touched on one corner with a piece of zinc1 which has been scraped bright1 the yellow coat of iodine moves off like a wave and disappears4 ,it is a very pretty process4 ,the zinc and silver forming together a voltaic pair1 with the salt water intervening1 oxidation of the zinc takes place1 and the silver surface commences to evolve hydrogen gas2 while this is in a nascent condition it decomposes the film of iodide of silver1 giving rise to the production of hydriodic acid1 which is very soluble in water1 and hence instantly removed4 ,this process1 therefore1 differs from that with hyposulphite4 ,the latter acts by dissolving the iodide of silver1 the former by decomposing it4 ,it is necessary not to leave the zinc in contact too long1 or it deposits stains1 and in large plates the contact should be made at the four corners successively1 to avoid this accident4 ,gilding ,solution4--,to one pint of pure rain or distilled water add fifteen grains of pure chloride of gold1 and to another pint add sixty grains of hyposulphite of soda4 ,when dissolved1 pour the gold solution into the hyposulphite by small quantities1 shaking well after each addition4 ,the soda solution must not be poured into the gold1 as the gold would be immediately decomposed1 and the solution turn black1 and be unfit for use4 ,some operators add muriate of potash and other substances1 but these do not possess any advantage except in cases where it is necessary to bleach the solarized portions of the impression1 and when such is the case1 chloride of sodium 7common salt7 is probably as effective and is the most convenient4 ,add about a teaspoonful to two ounces of the gilding4 ,solution1 for ,increasing the ,brilliancy of the ,daguerreotype4--,this solution will have the effect to thoroughly cleanse the surface of the gilded plate and excite a powerful influence on the general character of the impression4 ,to a solution of three ounces of water1 in which is dissolved a quarter of an ounce of cyanide of potassium1 add one teaspoonful of a solution containing six ounces of water and half an ounce of each pure carbonate of potash1 alum1 common salt1 gallic acid1 sulphate of copper1 and purified borax4 ,while the plate is wet1 pour on a little1 and heat it with a powerful blaze4 ,the effect will be quickly produced1 in from three to fifteen seconds4 ,rinse and dry1 as in the gilding4 ,bleaching ,solution4--,make a saturated solution of muriate of ammonia 7sal ammoniac7 in pure water1 and filter through paper4 ,reduce with an equal quantity of water when used4 ,when the linen or any other portion of the impression is badly solarized1 after removing the coating1 rinse with water2 then pour this upon the surface in the same manner as the gilding solution4 ,if the solarization be very deep1 apply the lamp beneath1 and warm the plate a trifle4 ,now pour off1 and1 without rinsing1 apply the gilding4 ,the whole operation must be quickly performed1 or the chlorine soon attacks the shades of the picture4 ,when properly done1 however1 the solarized parts are restored to a clear1 transparent white4 ,electro1 or ,cold ,gilding4--,this process ,i have adopted1 and it produces exceedingly beautiful impressions for the stereoscope1 adding a great charm to the pleasing effect of that instrument4 ,it also possesses a pretty and curious effect on views4 ,it is easy of trial1 and may be used by dissolving one gramme of chloride of gold in half a litre of ordinary water1 and thirty grammes of hyposulphite of soda in another half litre of similar water2 then pour the solution of chloride of gold into that of soda1 by little and little1 agitating it exactly as in ,m4 ,fizeau's preparation1 of which there is but a variation4 ,when you wish to use it1 pour some into a plate1 or any other vessel of the same kind1 sufficient to cover the proof2 then1 after having added to it a drop of ammonia1 immerse the plate in it as soon as you take it out of the mercury-box1 after having wiped its back and edges1 and agitate the mixture quickly from right to left1 so as to dissolve rapidly the coating of iodide of silver as usual4 ,as soon as the plate appears white1 cease all rapid motion1 but continue to give it a slight undulating one2 for if it were allowed to remain still for only a few minutes1 the proof would be clouded4 ,by little and little1 the surface of the plate takes a yellow tint1 which darkens more and more1 approaching to bistre4 ,you stop therefore1 at the color you wish2 and when the proof has been washed and dried1 in the manner previously explained1 it will be found to be fixed1 without any stain1 with a limpid surface1 and an extraordinary warm tone4 ,if you were to augment the proportions of the ammonia or chloride of gold1 the operation would progress much quicker1 but then the middle of the proof would be always much clearer than towards the border4 ,the mixture may be used several times without being renewed4 ,it does not1 however1 give such a beautiful color to the impression as when it is newly prepared4 ,by communicating to the vessel containing the solution a continual motion1 the impression1 when once immersed1 will be fixed4 ,during that time1 and while attending to anything else1 watch its color2 and at the end of ten minutes or a quarter of an hour1 take it out of the bath and dry it4 ,agent for ,neutralizing ,bromine1 ,chlorine1 and ,iodine ,vapors4--,aqua ammonia1 sprinkled about the chemical or coating room1 will soon neutralize all the vapor in the atmosphere of either chlorine1 bromine1 or iodine4 ,no operator should be without1 at least1 a six-ounce bottle filled with ammonia4 ,a little of its vapor about the camera-box has a decided and happy effect4 ,burnt coffee1 pulverized1 has also the property of destroying the vapors of the above chemicals1 as also almost any other agent employed about the ,daguerreotype room4 ,its deodorizing properties are such that if brought in contact with air filled with the odor of decomposing meat1 it will instantly destroy all disagreeable smell4 ,it can easily be used in the ,daguerreotype room by placing a little of the raw bean1 finely pulverized1 on an old plate1 and roasting it over the spirit-lamp4 ,buff ,dryer4--,there are various methods for keeping buffs dry and free from dust4 ,some place a sheet of iron against the wall at an angle sufficient to put a lamp between it and the wall1 and then let the buff rest against the top of the sheet4 ,by this method the buff is for its full length close to the heated iron1 and at the same time exposed to the heated atmosphere and any dust that may be free4 ,i would recommend some arrangement by which the buff would be inclosed4 ,i have found the following to answer the purpose well1 which is a box of sheet iron twenty inches long1 eight wide and five high1 with one end left open and the other closed2 the cover is made of the same material1 with the edges bent over to go on and off4 ,there are several wires running through the centre of the sides1 which it is necessary to cover with cloth or paper to absorb all the moisture that may be made by applying the heat1 and the buffs are put in and taken out at the open end4 ,in order that the heat may be as nearly uniform as possible1 an iron bar one inch wide1 eighteen inches long and one half inch thick1 is so bent that the centre is one quarter inch from the bottom of the box1 and that at least two inches of each end come in contact with the bottom2 this being riveted on the bottom1 and a lamp with a small blaze applied to the centre of the bar of iron4 ,this will constitute one of the best and cheapest buff dryers in use4 ,it may be suspended from the wall by placing wires around it1 or it may stand upon legs4 ,perhaps a more convenient plan is to place it under the workbench in a similar position to a drawer4 ,one precaution is necessary3 when first heating the dryer1 apply but a very gentle heat4 ,this will prevent an accumulation of moisture1 which would otherwise pass off in steam1 coming in contact with the buff1 thus causing a dampness4 ,another caution3 never have the temperature of the air in the heater more than ten degrees above that which surrounds it4 ,when wheels are used1 they should be encased in a sheet iron or wood case4 ,all those made for our market are provided in this respect4 ,keeping ,buffs in ,order4--,this is one of the most important objects to arrest the attention of the operator4 ,every buff is more or less liable to get out of order by dust falling upon or coming in contact with the polishing powder employed in cleaning the plate4 ,the edge of every plate should be thoroughly wiped and freed from any material that may adhere while cleaning4 ,i have adopted the following method1 which proves highly successful3 ,rub the buff leather1 holding the face down1 with the sharp edge of a pair of shears or a piece of glass4 ,this brings out any portion of the skin which may have become matted from any moisture1 and also takes out any substance imbedded in it1 and prevents it from scratching4 ,then1 with a stiff brush1 rub the buff well1 and it will be found to work well4 ,this same process employ on wheels and hand buffs every morning1 or oftener1 as occasion requires4 ,preparing ,buffs4--,two of these are necessary4 ,that part of the stick to be covered should be about eighteen or twenty inches long1 and three wide1 and made crowning on the face from one end to the other1 about one half inch4 ,before covering1 these are to be padded with two or three thicknesses of ,canton flannel4 ,the buff should not be too hard1 but padded with flannel1 so that by drawing it over the plate1 it may touch across the surface4 ,the only proper material for buffs is prepared buckskin2 and if prepared in a proper manner1 this needs nothing but to be tacked upon the stick4 ,there are several varieties of wheels employed2 the one most generally adopted is ,lewis' patent1 which consists of several varieties of wheels4 ,any operator can make a suitable wheel on the same plan of a turning lathe4 ,to ,clean ,buckskins4--,when the operator is compelled to purchase an unprepared buckskin1 the following is a good process for cleaning it3 ,there is always in the buckskin leather that is purchased1 more or less of an oily matter1 which is acquired in its preparation1 sometimes even amounting1 to a third of its weight4 ,the following is the mode of ridding it of this noxious ingredient3 ,dissolve1 in about six or seven quarts of filtered water1 about five ounces of potash2 when dissolved1 wash with the solution an ordinary buckskin2 when it has been well stirred in the liquid1 the water becomes very soapy1 owing to the combination of the potash with the oily matters contained in the skin4 ,throw away this solution and use some fresh water without potash and rather tepid2 change it several times until it remains quite limpid4 ,then gently stretch the skin to dry in an airy shaded place4 ,when thoroughly dried1 rub it well between the hands4 ,it thus becomes very pliant and velvet-like4 ,reflectors for ,taking ,views4--,there have been excellent cameras introduced for taking views1 but the time of exposure1 which is increased in proportion to the focal length1 is considered an objection2 consequently many adhere to the old plan of using the speculum1 or rather1 substitute a mirror4 ,i now have one which ,i have used for several years and find it equal to any article of the kind have ever tried4 ,one is easily made by a tin man1 at a trifling expense4 ,procure a piece of best plate looking-glass1 two and a half by five inches for a quarter1 or four by eight for a half-sized camera2 put a piece of pasteboard of the same size on the back1 to protect the silvering1 and stick around the edge in the same manner as in putting up a picture4 ,take a sheet of tin for the large size1 or a half sheet for the other2 place the glass crosswise in the centre2 bend the ends of the tin over the edge of the glass and turn them back so as to form a groove to hold the glass1 and still allow it to slide out and in4 ,these ends of the tin must be turned out flaring1 that they may not reflect in the glass4 ,have a tin band about an inch wide made to fit close on the end of the camera tube2 place it on1 and taking the tin containing the glass1 bring it to an angle of forty-five degrees with the tube1 extending nearly the whole length of the glass in front of the lenses2 lap the loose ends of the tin on each side of the tin rim1 and having your camera turned on the side to throw the view lengthwise1 arrange the exact angle by examining the image on the ground-glass4 ,when you have it exactly right1 hold it while it is soldered fast to the band4 ,take out your glass and stain the tin black1 to prevent reflection4 ,,chapter ,,iii4 ,,chemicals4 ,bromine and its ,compounds--,iodine and its ,compounds--,chlorine and its compounds--,cyanide of ,potassium--,hyposulphite of ,soda--,hyposulphite of ,gold--,nitric ,acid--,nitro-,muriatic ,acid--,hydrochloric ,acid--,hydrofluoric ,acid--,sulphuric ,acid--,accelerating ,substances--,liquid ,sensitives--,dry ,sensitives1 etc41 etc4 ,,bromine4 ,an article so extensively used in the practice of the ,daguerreotypic art as ,bromine1 is deserving of especial attention1 and accordingly every person should endeavor to make himself familiar with its properties and applications4 ,history4--,this element was discovered in #ahbf by ,m4 ,balard1 in the mother-liquor1 or residue of the evaporation of sea-water4 ,it is named from its offensive odor 7bromos1 bad odor74 ,in nature it is found in sea-water combined with alkaline bases1 and in the waters of many saline springs and inland seas4 ,the salt springs of ,ohio abound in the compounds of bromine1 and it is found in the waters of the ,dead ,sea4 ,the only use which has been made of bromine in the arts is in the practice of photography4 ,it is also used in medicine ,in a chemical point of view it is very interesting1 from its similarity in properties1 and the parallelism of its compounds to chlorine and iodine4 ,dr4 ,d4 ,alter1 of ,freeport1 ,pa41 is the only ,american manufacturer1 and furnishes all of the 8,american ,bromine40 ,yet we understand much purporting to be of ,german manufacture is prepared from that made in ,freeport4 ,this is done by individuals in this city1 who get well paid for the deception4 ,for the successful application of bromine as an accelerating agent1 we are indebted to ,mr4 ,john ,goddard of ,london1 who at the time was associated with ,mr4 ,john ,johnson1 now a resident of this city4 ,preparation4--,the mother-liquor containing bromides is treated with a current of chlorine gas1 which decomposes these salts1 setting the bromine free1 which at once colors the liquid to a reddish brown color4 ,ether is added and shaken with the liquid1 until all the bromine is taken up by the ether1 which acquires a fine red color and separates from the saline liquid4 #gd ,solution of caustic potash is then added to the ethereal solution1 forming bromide of potassium and bromate of potash4 ,this solution is evaporated to dryness1 and the salts being collected are heated in a glass retort with sulphuric acid and a little oxide of manganese4 ,the bromine is distilled1 and is condensed in a cooled receiver1 into a red liquid4 ,properties4--,bromine somewhat resembles chlorine in its odor1 but is more offensive4 ,at common temperatures it is a very volatile liquid1 of a deep red color1 and with a specific gravity of #c1 being one of the heaviest fluids known4 ,sulphuric acid floats on its surface1 and is used to prevent its escape4 ,at zero it freezes into a brittle solid4 ,a few drops in a large flask will fill the whole vessel when slightly warmed1 with blood red vapors1 which have a density of nearly #f4jj1 air being one4 ,it is a non-conductor of electricity1 and suffers no change of properties from heat1 or any other of the imponderable agents4 ,it dissolves slightly in water1 forming a bleaching solution4 ,chloride of ,bromine4--,this as an accelerating agent is by many considered superior #ge to the other ,bromide combinations4 ,it can be readily prepared by passing a current of chlorine through a vessel containing bromine4 ,a mixture of two parts muriatic acid and one of black oxide of manganese1 should be put into a flask having a bent tube to conduct the chlorine vapor into the bromine in another vessel4 ,this last vessel should also be supplied with a bent tube for conducting the combined vapors with a third vessel or receiver4 ,on the application of the heat from a spirit lamp to the bottom of the flask1 a current of chlorine gas will be disengaged1 and pass into the bromine1 when it readily combines1 and gives off a vapor1 which1 when condensed in the third vessel1 forms a volatile yellowish-red liquid4 ,it is best1 even at ordinary temperature1 to place the receiver in an ice bath4 ,for manner of using1 see farther on1 under head of ,accelerators4 ,bromides4--,a bromide treated with oil of vitriol1 disengages chlorohyadic acid2 but vapors of bromine are constantly disengaged1 at the same time imparting a brown color to the gas4 ,if the bromide be treated with a mixture of sulphuric acid1 and peroxide of manganese1 bromide is only disengaged4 ,a solution of a bromide gives1 with of nitrate #gf silver1 a light yellowish white precipitate of bromide of silver1 which is insoluble in an excess of acid1 and readily dissolves in ammonia4 ,the precipitated bromide is colored by light like the chloride1 but is immediately tinged brown1 while the chloride assumes at first a violet hue4 ,the bromides1 in solution1 are readily decomposed and chloride being set free1 colors the liquid brown4 ,in the whole range of heliographic chemicals there is probably not another collection less understood and being so productive of interesting investigation as the bromides4 ,bromide of ,iodine4--,m4 de ,valicours furnishes us with the best method for preparing this mixture3 8,into a bottle of the capacity of about two ounces1 pour thirty or forty drops of bromine1 the precise quantity not being of importance4 ,then add1 grain by grain1 as much iodine as the bromine will dissolve till quite saturated4 ,this point is ascertained when some grains of the iodine remain undissolved4 ,they may remain in the bottle1 as they will not interfere with the success of the preparation4 8,the bromide of iodine thus prepared1 from its occupying so small a space1 can very easily be carried1 but in this state it is much too concentrated to be used4 ,when it is to be employed1 pour a small quantity1 say fifteen drops1 by means of a dropping-tube1 into a bottle containing about half an ounce of filtered river water4 ,it will easily be understood that the bromide of iodine can be used with a greater or less quantity of water without altering the proportion which exists between the bromine and iodine40 ,this article forms a very good dry accelerator1 and is by some persons thought superior to all others1 as it works with great uniformity1 and is less liable to scum the plate in coating at high temperatures1 or when the thermometer indicates a heat above #fj deg4 ,bromide of ,potassium--,is prepared by mixing bromine and a solution of pure potass together1 and evaporating to dryness2 it crystallizes in small cubes1 and dissolves readily in water4 ,this agent is extensively employed in the paper and glass processes4 ,bromide of ,lime4 ,this the principal accelerator used in the ,american practice1 and is the best of all dry combinations at present employed4 ,there are many reasons why the dry is advantageous2 these are too familiar to repeat4 8,the bromide of lime may be produced by allowing bromine vapor to act upon hydrate of lime for some hours4 ,the most convenient method of doing this is to place some of the hydrate at the bottom of the flask1 and then put some bromine into a glass capsule supported a little above the lime4 ,as heat is developed during the combination1 it is better to place the lower part of the flask in water at the temperature of about #ej deg4 ,fah42 the lime gradually assumes a beautiful scarlet color1 and acquires an appearance very similar to that of the red iodide of mercury4 ,the chloro-iodide of lime may be formed in the same manner2 it has a deep brown color4 ,both these compounds1 when the vapor arising from them is not too intense1 have an odor analogous to that of bleaching powder1 and quite distinguishable from chlorine1 bromine1 or iodine alone40 ,farther on1 ,i have given1 in connection with accelerators1 a process ,i adopt1 which is far less tedious and equally reliable4 ,bromide of ,silver--,may be formed by pouring an alkaline bromide into a solution of nitrate of silver1 in the shape of a white1 slightly yellowish precipitate1 which is insoluble in water and nitric acid1 but readily dissolves in ammonia and the alkaline hyposulphites4 ,chlorine easily decomposes bromide of silver1 and transforms it into chloride4 ,m4 ,biot has expressed his opinion1 that it is not possible to find any substance more sensitive to light than the bromide of silver4 ,this is true to a certain extent1 but in combination with deoxidizing agents1 other preparations have a decided superiority over the pure bromide of silver4 ,bromide of ,gold--,is readily prepared by adding a little bromide to the brown gold of the assayers1 and allowing it to remain some time under water1 or assisting its action by a gentle heat4 ,it forms a salt of a bright crimson color1 but in its general properties is precisely similar to the chloride used in gilding4 ,bromide of ,magnesia--,is prepared in the same manner as bromide of lime4 ,this mixture is particularly adapted for hot climates1 and is used in this country by some few who regard its use as a valuable secret4 ,bromide of ,starch4--,this preparation is much used1 but not alone4 ,it is combined with lime by putting about one part in measure of starch to four of lime4 ,it is prepared by adding bromine to finely pulverized starch1 in the same manner as bromide of lime4 7,see ,accelerators47 ,experiments with ,bromine4--,place in a very flaring wine glass a few drops 7say ten7 of bromine1 then place a small piece of phosphorus about one-twentieth of an inch in diameter4 ,place the latter on the end of a stick from five to ten feet in length4 ,so place it that the phosphorus can be dropped into the glass1 and in an instant combustion giving a loud report will be the result4 b4 ,expose a daguerreotype plate to the vapor of bromine1 it assumes a leaden-grey color1 which1 blackens by light very readily4 ,exposing this to mercury will not produce any decided action upon the lights4 ,immerse it in the solution of the muriate of soda1 and the parts unacted upon by light becomes a jet black1 while the parts on which the light has acted will be dissolved off1 leaving a clean coating of silver4 ,this will be a most decided black picture on a white ground4 c4 ,expose an impressioned plate1 that has been sufficient time in the camera to become solarized1 to the vapors of bromine1 and the impression will be fully developed and exhibit no signs of solarization4 ,the exposure over the bromine most be very brief4 ,chlorine or iodine will produce the same result4 ,the latter is preferable4 ,again1 should the impressioned plate be exposed too long over the vapor of bromine1 the impression would be rendered wholly insensitive to the mercurial vapor4 ,hence this method is resorted to for restoring the sensibility of the plate when there is reason to believe that the impression would not be a desirable one2 as1 for example1 if a likeness of a child be wanted1 and it had moved before the plate had been sufficiently long exposed in the camera1 the plate may be restored to its original sensitiveness by re-coating over bromine1 as above1 thus saving the time and labor of re-preparing the plate for the chemicals4 d4 ,if by accident 7we would not advise a trial to any extent of this71 you should inhale a quantity of the vapor of bromine1 immediately inhale the vapor of aqua ammonia1 as this neutralizes the dangerous effect of the bromine vapor4 ,every operator should be provided with a bottle of ammonia1 as a little sprinkled about the chemical room soon disinfects it of all iodine or bromine vapor1 and also tends to facilitate the operation in the camera4 ,,iodine4 ,history of ,iodine4--,this is one of the simple chemical bodies which was discovered in #ahab by ,m4 ,courtois1 of ,paris1 a manufacturer of saltpetre1 who found it in the mother-water of that salt4 ,its properties were first studied into by ,m4 ,gay ,lussac4 ,it partakes much of the nature of chlorine and bromine4 ,its affinity for other substances is so powerful as to prevent it from existing in an isolated state4 ,it occurs combined with potassium and sodium in many mineral waters1 such as the brine spring of ,ashby-de-la-,zouche1 and other strongly saline springs4 ,this combination exists sparingly in sea-water1 abundantly in many species of fucus or sea-weed1 and in the kelp made from them4 ,it is an ingredient in the ,salt ,licks1 saline1 and brine springs of this country1 especially of those in the valley of the ,mississippi4 ,it is sparingly found in fresh-water plants1 as well also in coal1 and in combination with numerous other bodies4 ,fermented liquors contain iodine2 wine1 cider1 and perry are more iodureted than the average of fresh waters4 ,milk is richer in iodine than wine2 independently of the soil1 with which it varies1 the proportion of iodine in milk is in the inverse ratio of the abundance of that secretion4 ,eggs 7not the shell7 contain much iodine4 ,a fowl's egg weighing #ej gr4 contains more iodine than a quart of cow's milk4 ,iodine exists in arable land4 ,it is abundant in sulphur1 iron1 and manganese ores1 and sulphuret of mercury3 but rare in gypsum1 chalk1 calcareous and silicious earths4 ,any attempt to extract iodine economically should be made with the plants of the ferro-iodureted fresh waters4 ,most of the bodies regarded by the therapeutists as pectoral and anti-scrofulous are rich in iodine4 ,it is probably to the application of this body that we owe the discovery of the daguerreotype4 ,there is no record of the precise date when ,daguerre commenced experimenting with iodine1 but by the published correspondence between him and ,m4 ,neipce1 his partner1 it was previous to #ahcc4 ,there is no doubt1 however1 that the first successful application was made in #ahch1 as the discovery was reported to the world early in ,january1 #ahci4 ,preparation4--,iodine is mostly prepared from kelp1 or the half vitrified ashes of seaweed1 prepared by the inhabitants of the western islands1 and the northern shores of ,scotland and ,ireland4 ,it is treated with water1 which washes out all the soluble salts1 and the filtered solution is evaporated until nearly all the carbonate of soda and other saline matters have crystallized out4 ,the remaining liquor1 which contains the iodine1 is mixed with successive portions of sulphuric acid in a leaden retort1 and after standing some days to allow the sulphureted hydrogen1 etc41 to escape1 peroxide of manganese is added1 and the whole gently heated4 ,iodine distills over in a purple vapor1 and is condensed in a receiver1 or in a series of two-necked globes4 ,properties4--,iodine is solid at the ordinary temperature1 presenting the appearance of dark-grey or purple spangles1 possessing a high degree of metallic lustre4 ,it somewhat resembles plumbago1 with which it is sometimes diluted1 particularly when it is fine4 ,operators should endeavor to secure the larger crystals4 ,it melts at #bbd4f deg41 forming a brown or nearly black liquid4 ,it boils at about #cef deg41 and emits a very deep violet colored vapor4 ,it gives off a very appreciable vapor1 sufficient for all purposes of forming the iodide of silver on the daguerreotype plate1 at a temperature of #de deg4 or even lower4 ,iodine crystallizes readily4 ,every operator has found upon the side of the jar in his coating-box1 perfectly regular crystals1 deposited there by sublimation4 ,water dissolves but a small proportion of iodine1 requiring #gjjj parts of water to dissolve one of iodine1 #he or one grain to the gallon of water4 ,alcohol and ether dissolve it freely1 as does a solution of nitrate or hydrochlorate of ammonia and of iodides4 ,the density of solid iodine is #d4ie2 that of its vapor #h4gaf4 ,it greatly resembles chlorine and bromine in its combinations1 but its affinities are weaker4 ,it does not destroy the majority of organic substances1 and vegetable colors generally resist its action4 ,it combines with several organic substances1 imparting to them peculiar colors4 ,it colors the skin brown1 but the stain soon disappears4 ,chloride of ,iodine--,is formed by passing chlorine into a bottle containing some iodine4 ,this can be readily done by pouring one ounce and a half of muriatic acid upon a quarter of an ounce of powdered black oxide of manganese1 and heat it gradually in a flask1 to which is adapted a bent glass tube4 ,this tube must connect with the bottle containing the iodine1 and the yellowish-green gas disengaged will readily combine with the iodine1 forming a deep red liquid1 and the operation is complete4 ,the use of chloride of iodine will be referred to in connection with the ,accelerators4 #hf ,iodides4--,the iodide treated with the oil of vitriol1 instantly produces a considerable deposit of iodine2 and if the mixture be heated1 intense violent vapors are disengaged4 ,the reaction is due to the decomposition of oil of vitriol by iodohydric acid1 water and sulphurous acid being formed1 and iodine set free4 ,the iodides in solution are decomposed by chlorine1 iodine being precipitated1 the smallest quantity of which in solution is instantly detected by its imparting to starch an intensely blue color4 ,iodide of ,potassium4#d--,this compound is easily made in the following manner3 ,subject to a moderate heat a mixture of #ajj parts of iodine1 #ge of carbonate of potash1 #cj of iron filings1 and #abj parts of water4 ,this mass must be thoroughly dried and then heated to redness2 the resulting reddish powder is to be washed with water1 and the solution obtained filtered1 and evaporated to dryness4 ,it is found that #ajj parts of iodine yield #ace parts of very white1 but slightly alkaline1 iodide of potassium4 #d ,i shall present the preparation of only a few iodides1 and such as are more intimately connected with the ,daguerreotype4 ,experiment4--,on projecting dry pulverized iodide of potassium into fused anhydrous phosphoric acid1 a violent disengagement of iodine takes place1 attended by a transient ignition2 fused hydrate of phosphoric acid liberates iodine abundantly from iodide of potassium2 this reaction is accompanied by the phenomenon of flame and formation of a considerable quantity of hydriodic acid4 ,iodide of ,mercury4--,for the preparation of iodide of mercury1 ,dublanc recommends to cover #ajj grms4 of mercury with #a kilogrm4 of alcohol1 to add #abd grms4 of iodine gradually in portions of ten grms41 and agitating between each fresh addition1 until the alcohol becomes colorless again4 ,after the addition of the last #d grms4 the alcohol remains colored1 the whole of the mercury having become converted into iodide4 ,the resulting preparation is washed with alcohol2 it is crystalline and of a hyacinth color4 ,iodide of ,silver4--,this compound is formed upon every plate upon which a ,daguerreotype is produced4 ,the vapor of iodine coming in contact with the silver surface1 forms an iodide which is peculiarly sensitive to light4 ,the various colors produced are owing to the thickness of the coating1 and the maximum sensibility of the coating1 as generally adopted1 is when it assumes a deep yellow1 or slightly tinged with rose color4 ,this compound is largely employed in most photographic processes on paper1 and may be easily prepared by the following formula3 ,by adding iodide of potassium to a solution of nitrate of silver1 a yellowish-white precipitate of iodide of silver is obtained1 which is insoluble in water1 slightly soluble in nitric acid1 and soluble in a small degree in ammonia1 which properties seem easily to distinguish it from the chloride and bromide of silver4 ,chlorine decomposes it and sets the iodine free1 and chlorohydric acid converts it into a chloride4 ,it fuses below a red heat4 ,although the effect of light on the iodide is less rapid than on the chloride1 the former sooner turning black1 assuming a brown tinge2 but when in connection with gallic acid and the ferrocyanate of potash1 it forms two of the most sensitive processes on paper4 ,iodide of silver dissolves easily in a solution of iodide of potassium1 and the liquid deposits in evaporation crystals of a double iodide4 ,iodide of ,gold4--,if a solution of potassium be added to a solution of chloride of gold1 a precipitate of iodide of gold takes place1 soluble in an excess of the precipitate4 ,a little free potash should be added to combine with any iodide that may chance to be set free by the chloride of gold4 ,iodide of ,lime is prepared by adding iodine to hydrate of lime 7which will be referred to farther on7 until the mixture assumes a light yellow shade1 when wanted for combinations with accelerators1 or to a dark brown when employed for the first coating4 ,this latter mixture has been sold in our market under the name of 8,iodide of ,brome40 ,iodide of ,bromine4--7,see page #gf47 ,experiments with ,iodine4--,place a plate which has been exposed in the camera over the vapor of iodine for a very brief period1 and it will present the appearance of the impression having been solarized4 b4 ,upon a ,daguerreotype plate1 from which an impression has been effaced by rubbing or otherwise1 the picture may be made to reappear by merely coating it over with iodine4 c4 ,place in a vessel a little water1 into which put the smallest possible quantity of free iodine and add a little starch1 and the liquid will instantly assume a blue color4 ,advantage is taken of this fact in the laboratory to detect the presence of iodine in liquids4 ,the starch should be dissolved in boiling water and allowed to cool4 ,there are numerous other interesting experiments that can be performed by the aid of iodine1 but it is unnecessary here to consume more space4 ,,chlorine4 ,history4--,the ,swedish chemist1 ,scheele1 in #aggd1 while examining the action of hydrochloric acid on peroxide of manganese1 first noticed this element4 ,he called it dephlogisticated muriatic acid4 ,it was afterwards1 by the ,french nomenclaturists1 termed oxygenated muriatic acid1 conceiving it to be a compound of oxygen and muriatic acid4 ,this view of its notice was corrected by ,sir ,h4 ,davy 7in #ahji71 who gave it the present name4 ,in #ahdj-da1 this gas vas employed for accelerating the operation of light upon the iodized ,daguerreotype plate4 ,john ,goddard1 ,wolcott ,johnson1 ,claudet1 ,draper1 ,morse and others1 were among the first made acquainted with its use4 ,count ,rumford1 ,ritter1 ,scheele1 ,seebert and others1 experimented with chlorine in regard to its effect when exposed to the action of light in combination with silver4 ,in #ahde1 ,m4 ,edward ,becquerel announced that he had 8been successful in obtaining1 by the agency of solar radiations1 distinct impressions1 of the colors of nature40 ,on the #dth of ,march1 #ahea1 ,neipce1 ,st4 ,victor1 a former partner of ,,daguerre1 announced that he had produced 8all the colors by using a bath of bichloride of copper1 and that a similar phenomenon occurs with all salts of copper1 mixed with chlorine40 ,preparation4--,this is easily accomplished by putting about two parts of hydrochloric 7muriatic7 acid on one of powdered black oxide of manganese1 and heating it gradually in a flask or retort1 to which may be adapted a bent glass tube4 ,a yellowish-green gas is disengaged1 which being conducted through the glass tube to the bottom of a bottle1 can readily be collected1 being much heavier than the air1 displaces it completely and the bottle is filled 7which can be seen by the green color72 a greased stopper is tightly fitted to it1 and another bottle may be substituted4 ,in all experiments with chlorine1 care should be taken not to inhale the gas6 ,properties4--,chlorine is a greenish-yellow gas 7whence its name1 from chloros1 green71 with a powerful and suffocating odor1 and is wholly irrespirable4 ,even when much diluted with air1 it produces the most annoying irritation of the throat1 with stricture of the chest and a severe cough1 which continues for hours1 with the discharge of much thick mucus4 ,the attempt to breathe the undiluted gas would be fatal2 yet1 in a very small quantity1 and dissolved in water1 it is used with benefit by patients suffering under pulmonary consumption4 ,under a pressure of about four atmospheres1 it becomes a limpid fluid of a fine yellow color1 which does not freeze at zero1 and is not a conductor of electricity4 ,it immediately returns to the gaseous state with effervescence on removing the pressure4 ,water recently boiled will absorb1 if cold1 about twice its bulk of chlorine gas1 acquiring its color and characteristic properties4 ,the moist gas1 exposed to a cold of #cb deg41 yields beautiful yellow crystals1 which are a definite compound of one equivalent of chlorine and ten of water4 ,if these crystals are hermetically sealed up in a glass tube1 they will1 on melting1 exert such a pressure as to liquefy a portion of the gas1 which is distinctly seen as a yellow fluid1 not miscible with the water which is present4 ,chlorine is one of the heaviest of the gases1 its density being #b4dg1 and #ajj cubic inches weighing #gf4e grains4 ,chlorine ,water4--,this combination1 which is used in conducting ,m4 ,neipce's process1 can be readily prepared by conducting the gas into a bottle containing distilled water4 ,one part water dissolves two parts of chlorine4 ,chlorides4--,the metallic chlorides are nearly all soluble in water2 that of silver and protochloride of mercury being the only exceptions4 ,a metallic chloride1 treated with oil of vitriol1 disengages chlorohydric acid4 ,heated with a mixture of peroxide of manganese and sulphuric acid1 chlorine is given off1 which is easily recognized by its odor and other physical properties4 ,the chlorides dissolve in water2 give with nitrate of silver1 a white precipitate1 even in highly diluted solutions1 becoming violet colored and finally black when exposed to the light4 ,the rapidity of the change of color is proportioned to the intensity of the light4 ,it is insoluble in nitric acid1 but readily soluble in ammonia2 it fuses without decomposition1 forming1 when cold1 a tough1 horny mass1 and is reduced by hydrogen and by fusion with carbonate of soda1 or with resin4 ,chloride of ,bromine4 7,see page #gd47 ,chloride of ,iodine4 7,see page #he47 ,chloride of potassium4--or 7,muriate of ,potassa74--,dissolve half an ounce of carbonate of potassa in water1 and neutralize with muriatic acid4 ,upon concentrating the solutions1 cubic crystals will be obtained1 having a taste similar to common salt4 ,they consist of potassium and chloride1 and when dissolved in water they may be regarded as muriate of potassa4 ,chloride of ,lime4--,mix half an ounce of slacked lime 7hydrate of lime7 with six ounces of water1 and conduct into this milk of lime1 with frequent agitation1 as much chlorine gas as will evolve from two ounces of muriatic acid and half an ounce of black oxide of manganese4 ,the liquid clarifies by standing2 may be regarded as a solution of chloride of lime1 and must be protected from the air and light4 ,it may also be made without putting in the water with the hydrate of lime1 by merely passing the chlorine into the hydrate of lime4 ,this last is by some used in preparations for accelerating the operation of taking ,daguerreotypes1 but when used for this purpose it is in small quantities4 ,chloride of ,calcium4--,to one part of water add two parts of muriatic acid1 and add pieces of common chalk until effervescence ceases2 then filter through cotton cloth and evaporate it by placing it in all earthen or porcelain dish1 over a slow fire1 to the consistency of a syrup4 ,when cooling1 large prismatic crystals of chloride of calcium are formed4 ,these must be quickly dried by pressing between folds of blotting paper and kept carefully excluded from the air1 as it readily attracts hydrogen4 ,for most daguerreotype purposes1 the syrup may be at once evaporated to dryness4 ,this is frequently placed in the iodine coating box for the purpose of keeping the atmosphere dry4 ,it is so easily made that every operator can provide himself with it in a short time1 and at little expense4 ,chloride of ,gold4--,is prepared by dissolving gold in aqua regia1 a composition of one part of nitric to two parts of muriatic acid4 ,gold foil is the best for our purposes2 coin1 however1 answers1 in most cases1 for the daguerreotype operator1 as the alloy1 being so slight is not noticed in the gilding process4 ,when the latter is used1 it will facilitate the operation to beat it out1 forming a thin sheet1 and then cutting in small strips4 ,where purity is required1 foil is better4 ,the gold is placed in three or four times its own weight of the above acids4 ,for this purpose1 an evaporating dish is best 7a common saucer will do72 a moderate heat may be applied to favor the action4 ,the mixture should be stirred often with a glass rod2 care should be observed not to apply too much heat1 for at a temperature of about #cjj deg4 the chlorine would be expelled and leave a metallic precipitate1 which would require re-dissolving4 ,acid may at any time be added if necessary to dissolve the gold1 but it is advisable to add as little excess as possible1 as it would require more time to evaporate4 ,after all the gold has dissolved1 and the liquid assumes a deep red color1 the solution should be allowed to cool1 being stirred nearly all the time4 ,this salt is of a reddish-brown color4 ,it is rarely we find in our market good chloride of gold1 as common1 salt is used for the bulk2 and when the bottles are labelled 8#ae grains10 8#bj grains10 nine-tenths do not in reality contain exceeding five grains of chloride of gold4 ,the salt is mixed with the above solution when it is cooling1 and gives bright yellow crystals1 which some of our uninformed operators conceive to be the best quality4 ,chloride of ,silver4--7,oxide of ,silver47--,take any quantity of silver coin or other silver1 roll or hammer it thin2 cut in small pieces4 ,this in order to save time4 ,put the silver in a glass or earthen vessel 7,florence flask is best72 pour in nitric acid and water1 about three parts of the former to one of the latter4 ,the operation of cutting up the silver may be facilitated by applying a gentle heat4 ,this blue solution consists of oxide of silver and oxide of copper1 both combined with nitric acid4 ,should the operator wish a pure solution of silver1 which1 however1 is not always used1 he may obtain it in the following manner3 ,to separate the two metals contained in the above solution from each other1 put some bright copper coins into the solution and set it aside in a warm place for three or four days1 occasionally giving it a circular motion4 ,the separated laminae are pure silver1 which is to be digested with ammonia until it ceases to be colored blue4 ,the silver1 after being washed and dried1 is again dissolved in nitric acid1 and the liquid1 diluted with water1 is kept as solution1 of silver4 ,either of the above solutions 7the one of oxide of silver and copper1 and the pure silver solution7 may be prepared for use by putting them in a bottle1 with a quantity of water1 and adding common fine salt1 you obtain a white curdy precipitate of chloride of silver4 ,no matter how much salt is used1 provided enough be added to throw down all the chloride of silver4 ,this solution should be well agitated and then allowed to stand for a few minutes2 thus the white precipitate is in the bottom of the bottle4 ,when the water has become clear1 pour it off with care1 leaving the sediment behind1 then add a fresh quantity of clean water1 shake1 let settle1 and pour off as before4 ,repeat the same for several times1 and the excess of salt will disappear1 leaving the white precipitate1 which may be drained of the water and dried in the dark1 and kept free from light and air4 ,,cyanide ,,of ,,potassium4 ,cyanide of ,potassium4--,this important article is worthy the undivided attention of every ,daguerreotypist4 ,i here give ,mr4 ,smee's process for its preparation4 ,this is from that author's work entitled1 8,electro ,metallurgy10 ,american edition3 8,the cyanide of potassium1 so often alluded to while treating of the metallo-cyanides1 may be formed in several ways4 ,it may be obtained by heating to a dull redness the yellow ferrocyanate of potash1 in a covered vessel1 filtering and rapidly evaporating it4 ,the objection to this method1 however1 is that without great care the whole of the ferrocyanate is not decomposed1 a circumstance which much reduces its value for electro-metallurgy4 ,by boiling1 however1 the ignited residue with spirits of wine this difficulty is said to be overcome1 as the ferrocyanate is absolutely insoluble in that menstruum1 while the cyanuret1 at that heat1 freely dissolves1 and is as easily re-deposited on cooling4 8,there is1 however1 a much better process by which this salt may be formed1 viz4 by simply transmitting hydrocyanic acid through potassium4 ,although the modes of making this acid are very numerous1 there is but one which is likely to be employed on a very large scale1 and that is its formation from the yellow ferrocyanate by means of sulphuric acid4 ,this process is performed as follows3 any given weight of the yellow salt is taken and dissolved in about five times its weight of water2 this is placed in a retort1 or some such analogous vessel1 to which is then added a quantity of strong sulphuric acid1 twice the weight of the salt1 and diluted with three or four times its quantity of water4 ,a pipe is carried from the neck of the retort to the receiving bottle1 which should be kept as cool as possible4 8,for small operations1 those invaluable vessels1 ,florence flasks1 answer well3 a bent tube being connected at one end to its month1 the other passing into the second vessel2 heat should be cautiously applied by means of an ,argand lamp1 a little vessel of sand being placed under the flask1 which helps the acid to decompose the salt4 ,prussic acid is then generated and passes through the tube to the recipient vessel1 which is to be charged with liquor potassae4 8,when the potash is saturated1 the operation is completed4 ,the ,germans recommend a strong1 alcoholic solution of potassa to be used in the second vessel1 for in this case1 the hydrocyanic or prussic acid combines with the potassa1 forming a hydrocyanate of potassa1 or1 the water being abstracted1 the cyanuret of potassium1 which spontaneously precipitates1 on the saturation of the fluid1 the cyanuret1 being insoluble in strong alcohol4 ,the ferrocyanate of potash may be considered as containing three equivalents of hydrocyanic acid1 two of potash and one of iron2 but1 unfortunately1 we can only obtain half the acid from the salt1 owing to the formation of a compound during its decomposition which resists the action of the acid4 ,the decomposition of this salt taking #b equivalents or #dbf grains 7to avoid fractions7 would afford #c equivalents or #ha grains of hydrocyanic1 or prussic acid1 capable of forming #aih grains of cyanuret of potassium1 while in the retort there would remain #chd grains or #c equivalents of bisulphate of potash1 and #a equivalent or #agd grains of a peculiar compound1 said to contain #c equivalents of cyanogen1 #a of potassium1 and one of iron 7,pereira74 ,it is manifest that1 but for this later compound1 we might double the quantity of hydrocyanic acid from the yellow salt40 ,the decomposition just described is the one usually received2 but too much reliance must not be placed on its accuracy1 for the analysis of the several compounds is too difficult for the results to be fully admitted4 ,the residue left in the retort speedily turns to one of the blues1 identical with1 or allied to1 ,prussian blue4 ,this is at best a disagreeable process to conduct1 for the hydrocyanic acid formed adheres so strongly to the glass1 that1 instead of being freely given off1 bubbles are evolved suddenly with such explosive violence as occasionally to crack the vessel4 ,this may be remedied as far as possible by the insertion of plenty of waste pieces of platinum--if platinized1 so much the better1 as that facilitates the escape of the gas4 ,the heat should be applied to every part of the vessel1 and the flame should not be allowed to play upon one single part alone4 ,large commercial operations are performed in green glass or stone-ware retorts4 8,now for one word of advice to the tyro3 ,remember that you are working with prussic acid2 therefore1 never conduct the process in a room1 the fumes being quite as poisonous as the solution of the acid itself2 moreover1 have always a bottle of ammonia or chlorine by your side1 that should you have chanced to inhale more than is pleasant1 it will be instantly at hand to counteract any bad effects4 ,it is stated by ,pereira1 that a little sulphuric acid or hydroferrocyanic acid passes to the outer vessel1 but probably the amount would be of no consequence for electro-metallurgy1 otherwise1 it might be as well to use a ,woulfe's apparatus1 and discard the salt formed in the first vessel4 ,to the large manufacturer it may be worth considering whether some other metallo-cyanuret1 formed in a similar manner to the ferrocyanuret1 might not be more advantageously employed1 because the residue of the process last described contains a large quantity of cyanogen which the acid is unable to set free4 8,there are other modes of procuring prussic acid1 besides the one which has been so tediously described2 but these are found to be more expensive4 ,the only one which ,i shall now notice is the process by which it is obtained from bicyanide of mercury4 ,the bicyanide of mercury itself is formed when peroxide of mercury is digested with ,prussian blue1 the peroxide of mercury abstracting the whole of the cyanogen from the blue1 and leaving the oxides of iron at the bottom of the vessel4 ,the solution may be evaporated to dryness1 and one part of the salt dissolved in six of water2 one part of muriatic acid1 sp4 gr4 #a4ae1 is then added1 and the solution distilled1 when the whole of the hydrocyanic acid passes over1 and by being conducted into a solution of potassa1 as in the former process1 forms cyanuret of potassium4 ,this process1 though easier than the first described1 is rather given as a resource under peculiar circumstances than as one to be adopted by the large manufacturer4 ,the expense is the only objection1 but in a small quantity this cannot be a consideration4 8,in giving this very rough outline of the general mode of forming salts1 the minutiae necessary for chemical work have altogether been avoided1 and those parts alone are entered upon which are more immediately necessary for the electro metallurgist to know and practice for himself4 ,this will account for the long description of the cyanuret of potassium1 while the preparation of the equally important and even more used acids1 the sulphuric1 muriatic1 etc41 commonly found in commerce1 are altogether neglected4 8,in using solutions of cyanide of potassium1 the workman should not immerse his arms into them1 otherwise it occasionally happens that the solution produces very troublesome eruptions over the skin40 ,,hyposulphite ,,of ,,soda4 ,hyposulphite of ,soda4--,this salt forms one of the important chemicals for the ,daguerreotype operator4 ,its application to this art is of an interesting nature4 ,it is used to dissolve the sensitive salt of silver which remains unchanged during the exposure in the camera4 ,it has the property of readily dissolving the chloride1 bromide and iodide of silver4 ,it should be pure and free from sulphuret of sodium2 should this last be present1 it will cause brown spots of sulphurated silver upon the ,daguerreotype impression4 ,this annoyance is a great source of complaint from many operators1 and ever will be1 so long as it is prepared by men who have no reputation to lose1 and whose eyes are blinded by the 8,almighty ,dollar40 ,a good article may be prepared as follows3 8,mix one pound of finely pulverized carbonate of soda with ten ounces of flowers of sulphur1 and heat the mixture slowly in a porcelain dish till the sulphur melts4 ,stir the fused mass1 so as to expose all its parts freely to the atmosphere1 whereby it passes from the state of a sulphuret1 by the absorption of atmospheric oxygen1 into that of a sulphite1 with the phenomenon of very slight incandescence4 ,dissolve in water1 filter the solution1 and boil it immediately along with flowers of sulphur4 ,the filtered concentrated saline liquid will afford1 on cooling1 a large quantity of pure and beautiful crystals of hyposulphite of soda40 ,hyposulphite of ,gold4--,this compound salt is by a few considered preferable to the chloride of gold1 but our experience has induced us to use the latter1 believing we are enabled to produce a more brilliant and warm-toned impression with it4 ,when the hyposulphite of gold is used in gilding1 it requires less heat and a longer application1 as there is some danger of producing a glossy scum over some parts of the surface of the plate4 ,i prepare this salt as follows3 ,dissolve one part chloride of gold and four parts hyposulphite of soda in equal quantities of distilled water3 pour the gold into the hyposulphite solution1 in the same manner as in mixing the gilding solution2 let it stand until it becomes limpid2 filter and evaporate to dryness4 ,re-dissolve and add a few grains of burnt alum4 ,after standing a few hours1 filter and evaporate again4 ,if not sufficiently pure1 repeat the crystallization until it is so4 ,for gilding1 dissolve in water and use in the same manner as the common gilding solution4 ,n4,b4--,the four following mixtures were employed in ,neipce's process in his earliest experiments3 ,aqueous ,solution of ,bichloride of ,mercury4--,eight grains of bichloride of mercury in #aj1jjj grains of distilled water4 ,solution of ,cyanide of ,mercury4--,a flask of distilled water is saturated with cyanide of mercury1 and a certain quantity is decanted1 which is diluted with an equal quantity of distilled water4 ,acidulated ,white ,oil of ,petroleum4--,this oil is acidulated by mixing with it one tenth of pure nitric acid1 leaving it for at least #dh hours1 occasionally agitating the flask4 ,the oil1 which is acidulated1 and which then powerfully reddens litmus paper1 is decanted4 ,it is also a little colored1 but remains very limpid4 ,solution of ,chloride of ,gold and ,platinum4--,in order not to multiply the solutions1 take the ordinary chloride of gold1 used for fixing the impressions1 and which is composed of #a gramme of chloride of gold and #ej grains of hyposulphate of soda1 to a quart of distilled water4 ,with respect to chloride of platinum1 #d grains must be dissolved in #c quarts of distilled water2 these two solutions are mixed in equal quantities4 ,acids4--,i shall not go into the preparations of the various acids employed in the ,daguerreotype4 ,this would be useless to the operator1 as there are few1 if any1 that it would be advisable to prepare4 ,it is only necessary for the experimenter to be made acquainted with their properties1 and this in order to prevent any haphazard experiments1 which are too common among operators4 ,any person who may be desirous to try an experiment1 should first study the agents he wishes to employ4 ,by so doing much time and money will be saved2 while the searcher after new discoveries would rarely become vexed on account of his own ignorance1 or be obliged to avail himself of the experience of others in any department of science4 ,nitric ,acid--,exists in combination with the bases1 potash1 soda1 lime1 magnesia1 in both the mineral and vegetable kingdoms1 and is never found insoluble4 ,it has the same constituents as common air1 but in different proportions4 ,the strongest nitric acid contains in every pound1 two and a quarter ounces of water4 ,pure nitric acid is colorless1 with a specific gravity of #a4e1 and boiling at #bdh deg44 ,it is a most powerful oxidizing agent1 and is decomposed with more or less rapidity1 by almost all the metals1 to which it yields a portion of its oxygen4 ,the nitric acid of commerce1 is generally the article used by the ,daguerreotypist4 ,this usually contains some chlorine and sulphuric acid4 ,it is obtained by the distillation of saltpetre with sulphuric acid4 ,it is employed in the ,daguerreotype process for dissolving silver1 preparing chloride or oxide1 nitrate of silver1 the former used in galvanizing1 and in combination with muriatic acid for preparing chloride of gold1 used in gilding4 ,it is also used by some for preparing the plate4 ,acidulated ,solution4--,this solution is used for cleaning the surface of the ,daguerreotype plate4 ,it has the property of softening the silver1 and bringing it to a state in which it is very susceptible of being either oxidized or iodized1 hence it contributes to increase the sensibility of the plate4 ,the proportions are to one drop of acid add from #ae to #bj drops of water1 or make the solution about like sharp vinegar to the taste4 ,nitro-,muriatic ,acid4--,aqua ,regia is a compound menstruum invented by the alchemists for dissolving gold4 ,it is composed of colorless nitric acid 7aqua-fortis7 and ordinary muriatic acid2 the mixture is yellow1 and acquires the power of dissolving gold and platinum4 ,these materials are not properly oxidized2 it nearly causes their combination with chlorine1 which is in the ,muriatic acid4 ,hydrochloric ,acid 7,muriatic ,acid74--,this acid forms a valuable addition to the chemicals employed by the practical ,daguerreotypist4 ,this acid is formed by acting upon common salt 7which is chloride of sodium7 by concentrated sulphuric acid4 ,the water of the acid is decomposed1 and its hydrogen combines with the chloride of the salt to form muriatic acid1 and this unites with the sulphuric acid to form sulphate of soda2 #fj parts of common salt and #di parts of concentrated sulphuric acid1 afford1 by this mutual action1 #cg parts of muriatic acid and #gb parts of sulphate of soda4 ,the muriatic acid of commerce has usually a yellowish tinge1 but when chemically pure it is colorless4 ,the former is commonly contaminated with sulphurous acid1 sulphuric acid1 chlorine1 iron1 and sometimes with arsenic4 ,muriatic acid1 from the fact of the presence of the chlorine1 is used in the ,daguerreotype process for dissolving gold1 and in combination with various accelerators4 ,its presence can be detected by ammonia4 ,a strip of paper dipped in this and waved to and fro will emit a thick white smoke if the acid vapor be in the atmosphere4 ,the ammonia neutralizes the acid fumes4 ,by reversing the experiment we can determine whether vapor of ammonia be in the air1 and also deprive these suffocating and dangerous gases of their injurious properties1 and remove them from the air4 ,every ,daguerreotype operator should be furnished with1 at least1 a six ounce bottle of aqua ammonia4 ,its operation is very nearly the same on bromine and iodine vapor4 ,hydrofluoric ,acid 7,fluorohydric ,acid74--,this acid is used to form some of the most volatile and sensitive compounds employed in the ,daguerreotype4 ,it is one of the most dangerous bodies to experiment with3 it is volatile and corrosive1 giving off dense white fumes in the air4 ,it combines with water with great heat4 ,at #cb deg4 it condenses into a colorless fluid1 with a density #a4jfi4 ,it is obtained from decomposition of fluorspar by strong sulphuric acid4 ,it readily dissolves the silica in glass1 and consequently cannot be kept in a vessel of that material4 ,it is prepared and kept in lead4 ,it is employed in accelerators on account of its fluorine4 ,one small drop on the tongue of a dog causes death4 ,the operator who wishes to use it should pour some of the liquid for which he intends it into a graduate1 or other vessel1 and then add the desired quantity of acid4 ,if by accident any of the spray should fall upon the skin1 it should at once be copiously drenched with water4 ,sulphuric ,acid4--,there are two sorts of this acid3 one is an oily1 fuming liquid2 this is made in ,nordhausen1 in ,saxony1 and is commonly called 8,nordhausen sulphuric acid10 or oil of vitriol4 ,the other which is the kind used in connection with the ,daguerreotype1 is common sulphuric acid4 ,it is somewhat thinner1 and when undiluted is not fuming4 ,this acid may be obtained in a solid and dry state1 called anhydrous sulphuric acid4 ,the common sulphuric acid is made by burning sulphur1 which forms sulphurous acid4 ,to convert this into sulphuric acid and gain more oxygen1 nitric acid1 which is rich in that body1 is added4 ,it forms a limpid1 colorless fluid1 of a specific gravity of #a4h4 ,it boils at #fbj deg42 it freezes at #ae deg4 ,it is acrid and caustic1 and intensely acid in all its characters1 even when largely diluted4 ,its attraction for basis is such that it separates or expels all other acids1 more or less perfectly1 from their combinations4 ,its affinity for water is such that it rapidly absorbs it from the atmosphere1 and when mixed with water much heat is evolved4 ,it acts energetically upon animal and vegetable substances1 and is a poisonous1 dangerous substance to get on the skin4 ,it is a powerful oxidizing agent2 hence its use in the galvanic battery1 for which purpose it is mostly used by the ,daguerreotypist4 ,the fumes of this being so much more offensive than nitric acid1 the latter is sometimes used4 ,it is also employed in some of the more sensitive accelerators4 ,,accelerating ,,substances4 ,remarks on the ,accelerating substances ,used in the ,daguerreotype4--,i have now arrived at a point in this work1 where the eye of the ,daguerreotype public will intently search for something new4 ,this search will prove in vain1 at least so far as regards those who have enjoyed and embraced the opportunities for studying the principles of our art4 ,every experienced operator has in a degree become familiar with the mechanical uses of all the agents employed1 while ,i fear but few understand the properties1 and laws governing those properties1 which are so indispensable to produce an image impressed upon the silver surface4 ,there are three substances which form the bases for producing a ,daguerreotype2 silver1 iodine and bromine4 ,each forms a separate body which is indispensable to the operators success as the art is now practiced in ,america4 ,with these three1 compounds of great variety are formed4 ,the silver surface is first thoroughly cleaned and freed from all organic matter1 then exposed to vapor of iodine1 producing an iodide of silver4 ,the plate upon which is this salt1 is again exposed to the vapor of bromine1 forming a bromo-iodide of silver1 a salt also4 ,as most of the various accelerators are compounds of bromine1 with either chlorine or fluorine combination1 they partake somewhat of the nature of these latter1 giving results which can be detected by the experienced operator4 ,thus muriatic acid is added for its chlorine1 which can generally be detected by the impression produced1 being of a light1 soft1 mellow tone1 and in most cases presenting a brilliant black to that colored drapery4 ,those who wish to experiment with agents for accelerating substances1 should first study to well understand their peculiar nature and properties2 as well1 also1 to endeavor to find out what will be the probable changes they undergo in combination as an accelerator4 ,this should be done before making the experiments4 ,from the foregoing it will be seen that numerous compounds are formed from the same basis1 and1 consequently1 it would be a waste of time and a useless appropriation to devote more of our space than is necessary to give the principal and most reliable combination4 ,in ,america1 the words 8,quick0 and 8,quick ,stuff10 are more generally used for and instead of the more proper names1 8,sensitives10 or 8,accelerators10 etc4 ,as it has by use become common1 ,i frequently use it in this work4 ,liquid ,accelerator1 ,no4 #a4--,this mixture was used by me in #ahdi1 and is given as it appeared in my 8,system of ,photography10 published at the above date3 ,take pure rain or distilled water1 one quart1 filter through paper into a ground stopper bottle1 and add1 for warm weather1 one and a half ounce chloride of iodine2 or for cold1 one ounce2 then add one ounce bromine1 and shake well4 ,now with care not to allow the vapor to escape1 add drop by drop1 thirty drops of aqua ammonia1 shaking well at each drop4 ,care must be taken not to add more at a time1 as it evokes too much heat4 ,this mixed1 in equal proportions with ,john ,roach's quick1 forms an excellent chemical combination4 ,for this purpose1 take one and a half ounce of each1 to which add ten ounces water1 for warm weather1 or from six to seven for cold4 ,pour the whole into a large box1 and it will work from two to four months4 ,i am now using 7#ahdi7 one charged as above which has been in constant use for three months1 and works uniformly well4 ,the above is right for half or full size boxes1 but half of it would be sufficient for a quarter size box4 ,coat to the first shade of rose over iodine1 change to a deep rosy red over quick1 and black about one tenth the first4 ,i would not now recommend the addition of 8,john ,roach's quick10 as ,i believe equally good results can be produced without it4 ,this liquid is now used by many1 and is very good for taking views4 ,lime ,water ,quick4--,this mixture is more used at present than all the other liquids ever introduced4 ,it produced the most uniform results1 giving the fine soft tone so characteristic in pictures produces from accelerators containing chlorine4 ,to one quart of lime water 7this can be had of any druggist7 add one and a half ounce of pulverized alum4 ,this should be shook at intervals for twenty--four hours2 then add one ounce of chloride of iodine and three fourths ounce of bromine4 ,lime ,water4--,this is easily prepared by putting lime into water1 say a piece of quick-lime about the size of an egg into one quart of water4 ,this should be shook occasionally for two or three days and allowed to settle1 when the water can be poured off and used4 ,use4--,to one part of quick add six parts of water2 coat to a light yellow over the iodine1 to a rose color over the quick1 and recoat about one tenth4 ,the above coating may be increased or diminished1 it matters not1 so that there is not too much1 and the proper proportions are preserved4 ,some add to the above a small quantity of magnesia1 say about a teaspoonful to the quart of liquid4 ,liquid ,accelerator1 ,no4 #b4--,the following was for a long time used by one of the first houses in the ,united ,states1 and probably was one of the first liquids ever used4 ,it produces a fine-toned picture1 but is not considered as sure as the lime water quick3 ,take rain water one quart1 add pulverized alum until it is a little sour to the taste1 and a small piece1 say one half inch square1 of magnesia4 ,filter through paper1 and add chloride of iodine one half ounce1 bromine sufficient to take it up1 which is a little less than half an ounce4 ,charge with one of quick to six of water2 coat over iodine to a soft yellow1 nearly1 but not quite1 bordering on a rose2 over quick to a dark purple1 or steel1 and back one sixth to one tenth4 ,wolcott's ,american ,mixture4--,van ,loan ,quick4--,this mixture was first formed and used by ,t4 ,wolcott ,johnson and gained great celebrity for its productions4 ,i have now a bottle hermetically sealed that contains about a half ounce of this mixture prepared in #ahda by ,john ,johnson1 now a resident of this city1 and the former partner of ,mr4 ,wolcott4 ,the preparation of this mixture1 as furnished by ,mr4 ,johnson himself1 is given as follows3 8,one part of bromine1 eight parts of nitric acid1 sixteen parts of muriatic acid1 water one hundred parts4 ,this mixture should be allowed to stand for several days2 it improves by age4 8,use4--,a few drops say1 #f to #ab1 of this mixture1 should be put into about #f or #h ounces of water2 it will require frequent replenishing by the addition of a few more drops4 ,the plate should be coated over the dry iodine to a red just bordering on a slate1 and then exposed to the mixture only sufficiently long to change the color4 ,if this is not done in less than six seconds it is not strong enough4 ,re-coat over the iodine full one fourth as long as first coating40 ,this exceedingly volatile compound is difficult to control from its instability2 it is but little used4 ,the impressions successfully produced by this mixture are very brilliant1 and possess a pleasing peculiarity4 ,,dry ,,sensitives4 ,hydrate of ,lime4--,the operation by which water is combined with lime is called slaking4 ,take a piece of quick lime1 common lime used in mortar1 and immerse it in warm water for about fifteen seconds2 then place it in an iron or tin vessel4 ,it will soon begin to swell1 evolving a great deal of heat and emitting steam1 and soon falls into a fine powder1 hydrate of lime4 ,this should be well stirred and allowed to cool1 and then bottled in order to prevent it from giving off the hydrate and recovering the carbonic acid from the atmosphere4 ,the last is detrimental to its use with bromine1 and is one cause of the complaint that 8it will not take bromine40 ,the hydrate of lime should1 not be dried over a heat1 as has been supposed by many1 for in that case the hydrogen is expelled and it returns to a carbonate4 ,it is advisable to cool it in a damp place like a ground cellar4 ,much of the lime in our market will not1 except it be quite damp1 combine with the bromine4 ,this is owing to impurities4 ,nothing is equal to oyster-shell lime1 which ,i use altogether4 ,bromide of ,lime4--,in preparing large quantities of this1 we adopt the following method3 ,fill a four-quart bottle about two-thirds full of hydrate of lime2 pour into this about one or two ounces of bromine2 then shake well1 add more of the bromine1 shake well and let it stand for a few hours1 adding sufficient bromine to give it a fine red color4 ,it is better when kept in the large bottles1 as it forms a more perfect combination3 in other words it improves by age4 ,use4--,coat over the iodine to a rose red and then over this mixture to a purple or slate2 recoat over the first about one fourth as long as first coating4 ,gurneys ,american ,compound4--,of this compound there are two combinations1 one for use1 when the temperature of the atmosphere is above #fe or #gj deg41 and the other at a lower temperature4 ,the first is called ,no4 #a1 the second ,no4 #b4 ,no4 #a is prepared by placing hydrate of lime in a bottle1 say to three quarts of the hydrate of lime1 add one ounce of pulverized burnt alum1 and as much chloride of lime as can be put on a quarter of a dollar1 and from #ae to #cj grains of dry pulverized iodine1 or enough to change the color of the hydrate of lime1 to the slightest possible tinge of yellow4 ,there had better be less than carry the color to a deeper shade4 ,the object of using the iodine is to form a compound with bromine that is not so volatile as the bromine itself4 ,no matter how little iodine is combined with the bromine1 the vapors possess their relative proportion2 hence1 only enough iodine to prevent 8flaring10 or as it is often termed a 8scum-coating10 is used4 ,the iodine should be thoroughly combined with the lime1 which will take about one or two days4 ,should add bromine the same as in bromide of lime1 until the compound assumes a light red color4 ,no4 #b is prepared in the same manner as ,no4 #a1 except the addition of the iodine1 which is omitted4 ,use4--,no4 #a4 ,coat over the iodine to a bright yellow color1 then over the compound1 ,no4 #a1 to red color1 recoat over iodine1 about one sixth as long1 as the time occupied in first coating4 ,no4 #b4 ,coat over iodine same as above1 except recoat over the iodine about one fourth to one half as long as first coating4 ,dry ,quick1 ,no4 #a4--;,bromide of ,lime and ,starch4--,the following compound forms an excellent accelerator1 and is used by many4 ,it is claimed for this preparation1 that it will hold the bromine longer than others where starch is not employed4 ,as regards this claim we do not think it can be substantiated4 ,our experience in practice has led us to the conclusion that there is no great difference as respects durability1 but there is some little difference as regards the tone of the impressions produced by its use4 ,to one quart of hydrate of lime add one quart of finely pulverized starch4 ,to this mixture add bromine1 until it assumes a deep yellow or pink color4 ,starch may be added to any of the dry mixtures4 ,use4--,coat over the iodine to a deep yellow1 then over this quick to a red color1 recoat about one sixth of the time of first coating4 ,i will here again remark1 that the exact color of the coating is not essentially provided a proper proportion is preserved4 ,i have never seen it stated1 though it be a fact worthy of note1 that a proportionate time for coating over the iodine and accelerator1 will not answer4 ,for example3 if a plate exposed to the vapor of iodine be perfectly coated in sixteen seconds1 and then exposed to an accelerator1 7not having iodine in its combination7 receives its coating in four seconds1 it will be found that a proper proportionate coating cannot be preserved by adopting1 a proportion of time1 but on the contrary1 the time will diminish2 for exposure over the accelerator1 as in the above example1 if it be desired to coat the plate with twice as much iodine as in the above example1 the time would be1 over iodine thirty-two seconds1 and over the accelerator 7to possess a proper proportion7 from six to seven seconds4 ,hence it is that many inexperienced operators1 when wishing to vary their usual manner of coating1 fail in producing a favorable result4 ,they coat calculating a proportion of time when they should not4 ,dry ,quick1 ,no4 #b4--;,bromide of ,lime and ,magnesia4--,to one quart of hydrate of lime add one quart of magnesia1 and mix them well together2 add bromine same as in preparing bromide of lime2 coat the same as over dry quick ,no4 #a4 ,this combination produces very uniform results1 and is worked with much success by beginners4 ,chloro-,bromide of ,lime4--,to the bromide of lime add chloride of bromine until the mixture becomes a pale yellow color1 resembling sulphur4 ,it should be shook well1 and enough of the chloride of bromine added to bring the compound to a deep blood red color4 ,use4--,coat over the iodine to a pink color1 and then over the above to a red1 or just changing the color4 ,it should be remembered that accelerators containing chlorine do not admit of a great change of color of coating on the plate4 ,iodide of ,starch4--,this mixture can be employed for coating over in warm weather1 and prevent the flashing resulting at high temperatures4 ,it may be used the same as the iodide alone4 ,to six ounces of finely pulverized starch1 add one fourth ounce of dry iodine4 ,use4--,same as the dry iodine alone4 ,the same combination may be made with lime1 magnesia and other substances4 ,concentrated ,solution of ,iodine for ,first ,coating4--,it may appear strange to some of our old operators that an aqueous solution of iodine can be used for coating the plate and forming the iodide of silver4 ,it has long been a cry among most operators that it is impossible to succeed when the iodine box contains dampness4 ,now this is a great mistake1 and we will here state that in all cases where dampness appears upon a properly prepared ,daguerreotype plate1 it is the result of a different temperature of the metal from the air which surrounds it4 ,mr4 ,senter1 of ,auburn1 was the first of our operators who used a solution of iodine for coating the plate1 and we several years since saw his results1 which would rival the production of any other operator4 ,a concentrated solution of iodine is prepared by putting into a common bottle two thimblesful of hyposulphite of soda and a rather larger quantity of iodine1 so that there may be more than sufficient4 ,add to it about #dj ounces of common water 7heated to #fj or #gj degrees71 by little and little1 moving1 the bottle to warm it1 for fear of breaking4 ,after shaking it a short time1 the water is rapidly and strongly colored4 ,the solution should be poured into a bottle with a ground stopper1 and when cool used for iodizing4 ,a solution of sufficient strength can be made by moistening or just covering the iodine with water4 ,chloride of ,iodine as an ,accelerator4--,this is probably one of the best accelerators that can be used for coating the plate for taking views2 it works too slow1 however1 to meet the wants of the operating room1 yet its use was formerly1 for a long time1 adhered to by some of our best professors4 ,in producing views with this1 we are successful in obtaining well-developed impressions1 with a depth of tone and richness of appearance not to be met with in the productions of any other substances4 ,i give its use as furnished me by an old and experienced operator1 and published in ,humphrey's ,journal1 vol4 i4 p4 #ahj3 8,as the process of using chloride of iodine may be of interest to some of our subscribers1 ,i take pleasure in giving the following manipulation4 ,to one ounce of chloride of iodine add two ounces of water2 place this mixture in a coating-box1 the same as quick stuff2 coat the plate with dry iodine to a light yellow1 or lemon color2 then bring the coating to a deep pink over the chloride4 ,the plate must be recoated over the dry iodine40 ,this combination has been very successfully used in one of our most extensive establishments in this city1 and the superiority of the pictures produced by it was considered as an equivalent for the additional time required to bring out the impressions4 ,chlorine as an ,accelerator4--,i shall here refer to but a single experiment in which ,i employed chlorine gas for coating the plate4 ,i was provided with a retort1 the neck of which was fitted to the jar of my coating-box1 through a hole drilled for its reception4 ,this was fitted perfectly tight in my coating-box4 ,i placed some pure undiluted bromine water and the agents necessary for producing chlorine gas 7in small quantity7 in the retort4 ,the result was that my first experiment produced an impression completely solarized in all its parts by an exposure of four seconds of time1 which would have required an exposure of twenty seconds to produce a perfectly developed impression by the usual process4 ,another trial immediately produced one of the finest toned impressions ,i ever saw1 perfectly developed in one second of time4 ,my next two or three experiments proved total failures4 ,i was unable to produce even a sign of an impression4 ,by accident my retort was broken1 and not being in a locality convenient to obtain another1 my experiments were necessarily suspended4 ,my attention was not called to this subject again for several years1 when ,i noticed an account of some similar experiments by ,f4 ,a4 ,p4 ,barnard and ,dr4 ,w4 ,h4 ,harrington1 the latter of whom is now of the firm of ,dobyns ,harrington1 of ,new ,orleans4 ,from reading this article1 ,i found my own difficulties explained4 ,too much of the chlorine gas was present in my coating jar4 ,i would like to see some of our enterprising operators investigate this combination4 ,it is a singular fact1 that the vapors of bromine and chlorine combining upon the iodide of silver1 produce a more sensitive coating than when the two are combined in solution1 as in chloride of bromine solution4 ,those having ,humphrey's ,journal at hand1 can refer to vol4 i4 p4 #adb4 ,to use ,bromine ,water or other ,accelerators in ,hot ,weather4--,an excellent plan for using bromine water is as follows3 ,fill a two-ounce bottle quarter full of it1 and then fill the bottle with fine sand1 which serves to preserve a low temperature2 then place the bottle in a porous cup1 same as used in the battery2 fill this also with sand1 and close the end with plaster of ,paris4 ,place this in a coating-box1 and it will be found to act with great uniformity and be quite permanent4 ,bromide of ,lime1 another accelerator1 can be used in the same manner1 except it is1 only necessary1 when a solid sensitive is used1 to mix it with the sand without placing it in a bottle4 ,this method is employed with great success by a few1 who have regarded it as a secret worth keeping4 ,a ,combination1 requiring the ,use of only ,one ,coating-box4--,it is often wondered by beginners1 why some solution requiring only one coating cannot be employed4 ,this can be done1 but the results are not so satisfactory as when two or more are employed4 ,such an accelerator may be produced by adding alcoholic solution of iodine to a solution of chlorate of potash1 until the latter will take up no more of the former1 and to each ounce1 by measure of this solution1 ten drops of a saturated solution of bromide in water are added4 ,the solution of chlorate of potash is made by diluting1 one part of a saturated solution of the salt with ten parts of water4 ,the use of the chlorate is simply as a solvent of iodine4 ,fats as ,accelerators4--,the use of fats1 oils1 or greasy substances1 has been one of the most emphatic prohibitions about the ,daguerreotype plate4 ,yet it has been proved that its presence in a small quantity upon the silver surface has the effect of reducing the time of exposure in the camera from two-thirds to three-fourths4 ,an application may be made as follows3 ,pour sweet oil1 or rub beef or mutton fat1 on a common buff1 which is free from all polishing powders4 ,with this1 buff a well-cleaned plate1 and it will leave a scum1 which should be mostly removed by using another buff1 which should be clean4 ,coat the plate in the usual manner1 and the result will be a great reduction in the time of exposure in the camera4 ,the impression produced upon a plate so prepared presents1 when coming from the vapor of mercury1 a grey1 scummy appearance1 which1 on the application of heat in gilding1 does not improve2 hence its use is not generally adopted4 ,we have instituted some investigations upon this subject1 and in the present volume1 we shall not refer to it further4 ,those wishing to learn more fully the effect of light upon organic substances will find ,robert ,hunt's 8,researches on ,light0 an invaluable work4 ,,chapter ,,iv4 ,,light ,,and ,,optics4 ,light--,optics--,solar ,spectrum--,decomposition of ,light--,light1 ,heat1 and ,actinism--,blue ,paper and ,color for the ,walls of the ,operating ,room--,proportions of ,light1 ,heat1 and ,actinism composing a ,sunbeam--,refraction--,reflection--,len ses--,copying ,spherical ,aberration--,chromatic ,aberration4 ,it is advisable that persons engaging in the ,daguerreotype art should have at least a little knowledge of the general principles of light and optics4 ,it is not the author's design here to give a full treatise on these subjects1 but he only briefly refers to the matter1 giving a few facts4 ,it has been well observed by an able writer1 that it is impossible to trace the path of a sunbeam through our atmosphere without feeling a desire to know its nature1 by what power it traverses the immensity of space1 and the various modifications it undergoes at the surfaces and interior of terrestrial substances4 ,light is white and colorless1 as long as it does not come in contact with matter4 ,when in apposition with any body1 it suffers variable degrees of decomposition1 resulting in color1 as by reflection1 dispersion1 refraction1 and unequal absorption4 ,to ,sir ,i4 ,newton the world is indebted for proving the compound nature of a ray of white light emitted from the sun4 ,the object of this work is not to engage in an extended theory upon the subject of light1 but to recur only to some points of more particular interest to the photographic operator4 ,the decomposition of a beam of light can be noticed by exposing it to a prism4 ,if1 in a dark room1 a beam of light be admitted through a small hole in a shutter1 it will form a white round spot upon the place where it falls4 ,if a triangular prism of glass be placed on the inside of the dark room1 so that the beam of light falls upon it1 it no longer has the same direction1 nor does it form a round spot1 but an oblong painted image of seven colors--red1 orange1 yellow1 green1 blue1 indigo1 and violet4 ,this is called the solar spectrum1 and will be readily understood by reference to the accompanying diagram1 ,fig4 #a4 #acc ,to those who are unacquainted with the theory of light 7and for their benefit this chapter is given71 it may be a matter of wonder how a beam of light can be divided4 ,illustration3 ,fig4 #a ,this can be understood when ,i say1 that white light is a bundle of colored rays united together1 and when so incorporated1 they are colorless2 but in passing through the prism the bond of union is severed1 and the colored rays come out singly and separately1 because each ray has a certain amount of refracting 7bending7 power1 peculiar to itself4 ,these rays always hold the same relation to each other1 as may be seen by comparing every spectrum or rainbow2 there is never any confusion or misplacement4 ,there are various other means of decomposing #acd white light besides the prism1 of which one of the principal and most interesting to the ,daguerreotypist is by reflection from colored bodies4 ,if a beam of white light falls upon a white surface1 it is reflected without change2 but if it falls upon a red surface1 only the red ray is reflected3 so also with yellow and other colors4 ,the ray which is reflected corresponds with the color of the object4 ,it is this reflected decomposed light which prevents the beautifully-colored image we see upon the ground glass in our cameras4 ,illustration3 ,fig4 #b ,a sunbeam may be capable of three divisions--,,light1 ,,heat1 and ,,actinism2 the last causes all the chemical changes1 and is the acting power upon surfaces prepared to receive the photographic image4 ,the accompanying illustration1 ,fig4 #b1 will readily bring to the mind of the reader the relation of these one to another1 and their intensities in the different parts of a decomposed sunbeam4 ,the various points of the solar spectrum are represented in the order in which they occur between ,a1 and ,b1 this exhibits the limits of the ,newtonian spectrum1 corresponding with ,fig4 #a4 ,sir ,john ,herschel and ,seebeck have shown that there exists1 beyond the violet1 a faint violet light1 or rather a lavender to b1 to which gradually becomes colorless2 similarly1 red light exists beyond the assigned limits of the red ray to a4 ,the greatest amount of actinic power is shown at ,e opposite the violet2 hence this color 8exerts0 the greatest amount of influence in the formation of the photographic image4 7,blue paper and blue color have been somewhat extensively used by our ,daguerreotype operators in their operating rooms and skylights1 in order to facilitate the operation in the camera4 ,i fancy1 however1 that this plan cannot be productive of as much good as thought by some1 from the fact1 that the light falling upon the subject1 and then reflected into the camera1 is1 coming through colorless glass1 not affected by such rays as may be reflected from the walls of the operating room2 and even if it were so1 ,i conceive that it would be injurious1 by destroying the harmony of shadows which might otherwise occur47 ,the greatest amount of white light is at ,c2 the yellow contains less of the chemical power than any other portion of the solar spectrum4 ,it has been found that the most intense heat is at the extreme red1 b4 ,artificial lights differ in their color2 the white light of burning charcoal1 which is the principal light from candles1 oil and gas1 contains three rays--red1 yellow1 and blue4 ,the dazzling light emitted from lime intensely heated1 known as the ,drummond light1 gives the colors of the prism almost as bright as the solar spectrum4 ,if we expose a prepared ,daguerreotype plate or sensitive paper to the solar spectrum1 it will be observed that the luminous power 7the yellow7 occupies but a small space compared with the influence of heat and chemical power4 ,r4 ,hunt1 in his ,researches on ,light1 has presented the following remarks upon the accompanying illustration3 ,illustration3 ,fig4 #c 8,if the linear measure1 or the diameter of a circle which shall include the luminous rays1 is #be1 that of the calorific spectrum will be #db4aj1 and of the chemical spectrum #ee4aj4 ,such a series of circles may well be used to represent a beam from the sun1 which may be regarded as an atom of ,light1 surrounded with an invisible atmosphere of ,heat1 and another still more extended1 which possesses the remarkable property of producing chemical and molecular change4 ,a ray of light1 in passing obliquely through any medium of uniform density1 does not change its course2 but if it should pass into a denser body1 it would turn from a straight line1 pursue a less oblique direction1 and in a line nearer to a perpendicular to the surface of that body4 ,water exerts a stronger refracting power than air2 and if a ray of light fall upon a body of this fluid its course is changed1 as may be seen by reference to ,fig4 #d4 ,illustration3 ,fig4 #d ,it is observed that it proceeds in a less oblique direction 7towards the dotted line71 and1 on passing on through1 leaves the liquid1 proceeding in a line parallel to that at which it entered4 ,it should be observed that at the surface of bodies the refractive power is exerted1 and that the light proceeds in a straight line until leaving the body4 ,the refraction is more or less1 and in all cases in proportion as the rays fall more or less obliquely on the refracting surface4 ,it is this law of optics which has given rise to the lenses in our camera tubes1 by which means we are enabled to secure a well-delineated representation of any object we choose to picture4 ,when a ray of light passes from one medium to another1 and through that into the first again1 if the two refractions be equal1 and in opposite directions1 no sensible effect will be produced4 ,the reader may readily comprehend the phenomena of refraction1 by means of light passing through lenses of different curves1 by reference to the following diagrams3-- ,illustration3 ,fig4 #e1 #f1 #g ,fig #e represents a double-convex lens1 ,fig4 #f a double-concave1 and ,fig4 #g a concavo-convex or meniscus4 ,by these it is seen that a double-convex lens tends to condense the rays of light to a focus1 a double-concave to scatter them1 and a concavo-convex combines both powers4 ,if parallel rays of light fall upon a double-convex lens1 ,d ,d1 ,fig4 #h1 they will be refracted 7excepting such as pass directly through the centre7 to a point termed the principal focus4 ,illustration3 ,fig4 #h ,the lines ,a ,b ,c represent parallel rays which pass through the lens1 ,d ,d1 and meet at ,f2 this point being the principal focus1 its distance from the lens is called the focal length4 ,those rays of light which are traversing a parallel course1 when they enter the lens are brought to a focus nearer the lens than others4 ,hence the difficulty the operator sometimes experiences by not being able to 8obtain a focus10 when he wishes to secure a picture of some very distant objects2 he does not get his ground glass near enough to the lenses4 ,again1 the rays from an object near by may be termed diverging rays4 ,this will be better comprehended by reference to ,fig4 #i1 where it will be seen that the dotted lines1 representing parallel rays1 meet nearer the lenses than those from the point ,a4 ,the closer the object is to the lenses1 the greater will be the divergence4 ,this rule is applicable to copying4 ,did we wish to copy a #a_/f size ,daguerreotype on a #a_/af size plate1 we should place it in such a position to the lenses at ,a that the focus would be at ,f1 where the image would be represented at about the proper size4 ,now1 if we should wish to copy the #a_/f size picture1 and produce another of exactly the same dimensions1 we have only to bring it nearer to the lenses1 so that the lens ,d ,e shall be equi-distant from the picture and the focus1 i4 e4 from ,a to ,b4 ,the reason of this is1 that the distance of the picture from the lens1 in the last copy1 is less than the other1 and the divergence has increased1 throwing1 the focus further from the lens40 ,illustration3 ,fig4 #i ,these remarks have been introduced here as being important for those who may not understand the principles of enlarging or reducing pictures in copying4 ,i would remark that the points ,f and ,a1 in ,fig4 #i1 are termed 8conjugate foci40 ,if we hold a double-convex lens opposite any object1 we find that an inverted image of that object will be formed on a paper held behind it4 ,to illustrate this more clearly1 ,i will refer to the following woodcut3 ,illustration3 ,fig4 #aj 8,if ,a ,b ,c is an object placed before a convex lens1 ,l ,l1 every point of it will send forth rays in all directions2 but1 for the sake of simplicity1 suppose only three points to give out rays1 one at the top1 one at the middle1 and one at the bottom2 the whole of the rays then that proceed from the point ,a1 and fall on the lens ,l ,l1 will be refracted and form an image somewhere on the line ,a ,g ,e1 which is drawn direct through the centre of the lens2 consequently the focus ,e1 produced by the convergence of the rays proceding from ,a1 must form an image of ,a1 only in a different relative position2 the middle point of ,c being in a direct line with the axis of the lens1 will have its image formed on the axis ,f1 and the rays proceeding from the point ,b will form an image at ,d2 so that by imagining luminous objects to be made up of all infinite number of radiating points and the rays from each individual point1 although falling on the whole surface of the lens1 to converge again and form a focus or representation of that point from which the rays first emerged1 it will be very easy to comprehend how images are formed1 and the cause of those images being reversed4 8,it must also be evident1 that in the two triangles ,a ,g ,b and ,d ,g ,e1 that ,e ,d1 the length of the image1 must be to ,a ,b1 the length of the object1 as ,g ,d1 the distance of the image1 is to ,g ,b1 the distance of the object from the lens4 ,it will be observed that in the last cut the image produced by the lens is curved4 ,now1 it would be impossible to produce a well-defined image from the centre to the edge upon a plain surface2 the outer edges would be misty1 indistinct1 or crayon-like4 ,the centre of the image might be represented clear and sharp on the ground glass1 yet this would be far from the case in regard to the outer portions4 ,this is called spherical aberration1 and to it is due the want of distinctness which is frequently noticed around the edges of pictures taken in the camera4 ,to secure a camera with a flat1 sharp1 field1 should be the object of every operator2 and1 in a measure1 this constitutes the great difference in cameras manufactured in this country4 ,spherical aberration is overcome by proper care in the formation of the lens3 8,it can be shown upon mathematical data that a lens similar to that given in the following diagram--one surface of which is a section of an ellipse1 and the other of a circle struck from the furthest of the two foci of that ellipse--produces no aberration4 8,at the earliest period of the employment of the camera obscura1 a double-convex lens was used to produce the image2 but this form was soon abandoned1 on account of the spherical aberration so caused4 ,lenses for the photographic camera are now always ground of a concavo-convex form1 or meniscus1 which corresponds more nearly to the accompanying diagram40 ,illustration3 ,fig4 #aa ,chromatic ,aberration is another difficulty that opticians have to contend with in the manufacturing of lenses4 ,it will be remembered1 that in a former page 7#acc7 a beam of light is decomposed by passing through a glass prism giving seven distinct colors--red1 orange1 yellow1 green1 blue1 indigo and violet4 ,now1 as has been said before1 the dissimilar rays having an unequal degree of refrangibility1 it will be impossible to obtain a focus by the light passing through a double-convex lens without its being fringed with color4 ,its effect will be readily understood by reference to the accompanying cut4 ,illustration3 ,fig4 #h ,if ,l ,l be a double convex-lens1 and ,r ,r ,r parallel rays of white light1 composed of the seven colored rays1 each having a different index of refraction1 they cannot be refracted to one and the same point2 the red rays1 being the least refrangible1 will be bent to r1 and the violet rays1 being the most refrangible1 to v3 the distance v r constitutes the chromatic aberration1 and the circle1 of which the diameter is a l1 the place or point of mean refraction1 and is called the circle of least aberration4 ,if the rays of the sun are refracted by means of a lens1 and the image received on a screen placed between ,c and o1 so as to cut the cone ,l a l ,l1 a luminous circle will be formed on the paper1 only surrounded by a red border1 because it is produced by a section of the cone ,l a l ,l1 of which the external rays ,l a ,l l1 are red2 if the screen be moved to the other side of o1 the luminous circle will be bordered with violet1 because it will be a section of the cone ,m a ,m l1 of which the exterior rays are violet4 ,to avoid the influence of spherical aberration1 and to render the phenomena of coloration more evident1 let an opaque disc be placed over the central portion of the lens1 so as to allow the rays only to pass which are at the edge of the glass2 a violet image of the sun will then be seen at v1 red at r1 and1 finally1 images of all the colors of the spectrum in the intermediate space2 consequently1 the general image will not only be confused1 but clothed with prismatic colors40 ,to overcome the difficulty arising from the chromatic aberration1 the optician has only to employ a combination of lenses of opposite focal length1 and cut from glass possessing different refrangible powers1 so that the rays of light passing through the one are strongly refracted1 and in the other are bent asunder again1 reproducing white light4 ,to the photographer one of the most important features1 requiring his particular attention1 is1 that he be provided with a good lens4 ,by the remarks given in the preceding pages1 he will be enabled1 in a measure1 to judge of some of the difficulties to which he is occasionally subjected4 ,we have in this country but two or three individuals who are giving their attention to the manufacture of lenses1 and their construction is such1 that they are quite free from the spherical or chromatic aberration4 ,,chapter ,v4 ,to make ,plates for the ,daguerreotype--,determining the ,time of ,exposure in the ,camera--,instantaneous ,process for ,producing ,daguerreotype--,galvanizing the ,daguerreotype ,plate--,silvering ,solution--,daguerreotype without ,mercury--,management of ,chemicals--,hints and ,cautions--,electrotyping--,crayon ,daguerreotypes--,illuminated ,daguerreotypes--,natural ,colors in ,heliography--,multiplying ,daguerreotypes on one ,plate--,deposit in ,gilding--,practical ,hints on the ,daguerreotype4 ,,to ,,make ,,plates ,,for ,,the ,,daguerreotype4 ,i do not give the method employed by our regular plate manufacturers2 this is not important1 as the operator could not possibly profit by it from the fact of the great expense of manufacturing4 ,the following will be found practical3 ,procure a well planished copper plate of the required size1 and well polish it1 first with pumice stone and water1 then with snake stone1 jewelers' rouge4 ,plates can be purchased in a high state of preparation from the engravers4 ,having prepared the copper-plate1 well rub it with salt and water1 and then with the silvering powder4 ,no kind answers better than that used by clock-makers to silver their dial-plates4 ,it is composed of one part of well washed chloride of silver1 five parts of cream of tartar1 and four parts of table salt4 ,this powder must be kept in a dark vessel1 and in a dry place4 ,for a plate six inches by five1 as much of this composition as can be taken up on a shilling is sufficient4 ,it is to be laid in the centre of the copper1 and the figures being wetted1 to be quickly rubbed over every part of the plate1 adding occasionally a little damp salt4 ,the copper being covered with the silvering is to be speedily well washed in water1 in which a little soda is dissolved1 and as soon as the surface is of a fine silvery whiteness1 it is to be dried with a very clean warm cloth4 ,in this state the plates may be kept for use4 ,the first process is to expose the plate to the heat of a spirit flame1 until the silvered surface becomes of a well-defined golden-yellow color2 then1 when the plate is cold1 take a piece of cotton1 dipped in very dilute nitric acid1 and rub lightly over it until the white hue is restored1 and dry it with very soft clean cloths4 ,a weak solution of the hydriodate of potash1 in which a small portion of iodine is dissolved1 is now passed over the plate with a wide camel's hair brush4 ,the silver is thus converted1 over its surface1 into an ioduret of silver2 and in this state it is exposed to light1 which blackens it4 ,when dry1 it is to be again polished1 either with dilute acid or a solution of carbonate of soda1 and afterwards with dry cotton1 and the smallest possible portion of prepared chalk3 by this means a surface of the highest polish is produced4 ,the rationale of this process is1 in the first place1 the heat applied dries off any adhering acid1 and effects more perfect union between the copper and silver1 so as to enable it to bear the subsequent processes4 ,the first yellow surface appears to be an oxide of silver with1 possibly1 a minute quantity of copper in combination1 which being removed leaves a surface chemically pure4 ,another ,method4--,the best and simplest mode with which we are acquainted is to divide an earthenware vessel with a diaphragm3 one side should be filled with a very dilute solution of sulphuric acid1 and the other with either a solution of ferroprussiate of potash1 or muriate of soda1 saturated with chloride of silver4 ,the copper plate1 varnished on one side1 is united1 by means of a copper wire1 with a plate of zinc4 ,the zinc plate being immersed in the acid1 and the copper in the salt1 a weak electric current is generated1 which precipitates the silver in a very uniform manner over the entire surface4 ,another ,method4--,a piece of brass or of polished copper1 brass is preferred1 is perfectly planished and its surface made perfectly clean4 ,a solution of nitrate of silver1 so weak that the silver is precipitated slowly1 and a brownish color1 on the brass1 is laid uniformly over it1 8at least three times10 with a camel's hair pencil4 ,after each application of the nitrate1 the plate should be rubbed gently in one direction1 with moistened bitartrate of potassa1 applied with buff4 ,this coat of silver receives a fine polish from peroxide of iron and buff4 ,proofs are said to have been taken on it1 comparable with those obtained on ,french plates4 ,m4 ,,soliel',s ,,process ,,for ,,determining ,,the ,,time ,,of ,,exposure ,,in ,,the ,,camera4 ,m4 ,soliel has proposed the use of the chloride of silver to determine the time required to produce a good impression on the iodated plate in the camera4 ,his method is to fix at the bottom of a tube1 blackened within1 a piece of card1 on which chloride of silver1 mixed with gum or dextrine1 is spread4 ,the tube thus disposed is turned from the side of the object of which we wish to take the image1 and the time that the chloride of silver takes to become of a greyish slate color will be the time required for the light of the camera to produce a good effect on the iodated silver4 ,,instantaneous ,,process ,,for ,,procuring ,,daguerreotypes4 ,the following method of producing ,daguerreotypes has by some been named as above4 ,most experienced operators have been long acquainted with the effect of the vapor of ammonia upon the chemically coated plate4 ,i will here insert ,mr4 ,w4 ,h4 ,hewett's plan of proceeding4 ,this gentleman1 in referring to it 7published in #ahde71 says3 8,this improvement consists in using the vapor of ammonia1 as an object to accelerate the action of light upon the plate4 ,the effect is produced upon a simple iodized plate1 but still more upon a plate prepared in the ordinary way1 with both iodine and bromine4 ,by this means1 the author obtained impressions instantaneously in the sunshine1 and in five to ten seconds in a moderate light2 and he hopes to be able to take moving objects4 ,it can be applied by exposing the prepared plate over a surface of water1 to which a few drops of ammonia have been added 7sufficient to make it smell of ammonia72 or the vapor can be introduced into the camera during the action4 ,in fact1 the presence of ammonia1 in the operating-room1 appears to have a good effect1 as it also neutralizes the vapors of iodine and bromine that may be floating about1 and which are so detrimental to the influences of light upon the plate40 ,,galvanizing ,,the ,,daguerreotype ,,plate4 ,in consideration of the importance of galvanized plates1 ,i shall endeavor to give as plain and concise a manner of manipulation as possible4 ,for some time it was a question among the operators generally1 as to the beneficial result of electrotyping1 the ,daguerreotype plate1 but for a few years past our first operators have found it a fact1 that a well electro-silvered surface is the best for producing a portrait by the ,daguerreotype4 ,from my own experiments1 ,i have found that a plate1 by being galvanized1 can be rendered more sensitive to the operation of the light in proportion of one to five1 viz43 if a plate as furnished by the market1 be cleaned1 polished1 coated and exposed in the camera1 if the required time to freely develop an impression be ten seconds1 a similar plate prepared in like manner and galvanized1 will produce an equally well-defined image in eight seconds4 ,in connection with this subject1 there is one fact worthy of notice2 a plate with a very heavy coating of pure silver1 will not produce an equally developed image1 as a plate with a thinner coating1 hence the thin coating1 providing it entirely covers the surface1 is the best1 and is the one most to be desired4 ,the experiment is plain and simple4 ,let the slate receive a heavy or thick coating by the electrotype1 then polish1 coat1 expose in the usual manner1 and the result will be a flat1 ashy1 indistinct impression2 when1 on the other hand1 the thin coating will produce a bright1 clear and distinct image1 with all the details delineated4 ,the style of battery best for the purpose has been1 and now is1 a question of dispute among operators2 some preferring the ,daniell battery to ,smee's4 ,some claim the superiority of the first from its uniformity of action2 others1 of the latter1 for its strength4 ,i consider either good1 and for the inexperienced would prefer the ,daniell4 ,this is more simple in its construction1 while it has certainty in action4 ,the more skillful electrotyper would prefer ,smee's1 and this is the one most generally in use4 ,i would remark that the plan of galvanizing plates should be followed by every operator1 and when once thoroughly tested1 no one will abandon it4 ,,silvering ,,solution4 ,to any desired quantity of chloride of silver in water add1 little by little1 cyanide of potassium1 shaking well at each addition1 until all the cyanide is dissolved4 ,continue this operation1 and add the cyanide1 until all the precipitate is taken up and held in solution4 ,this solution is now ready for the plate-cup4 ,enough water may be added to cover any sized plate when held perpendicular in the cup4 ,the strength of the solution may be kept up by occasionally adding the chloride of silver and cyanide of potassium4 ,there should alway be a very little excess of the cyanide4 ,the plate should be well cleaned and buffed1 and the solution well stirred before it is immersed4 ,care should be observed to keep the solution clean1 and allow no particle of dust to come in contact with the surface of the plate4 ,the plate is now to be attached to the pole of the battery4 ,after remaining a short time1 it assumes a blue color2 take it out1 rinse freely with pure water1 then dry with a spirit lamp1 and it is ready for buffing4 ,buff and coat in the usual manner4 ,some operators are in the practice of immersing the plate in the solution and buffing twice4 ,this additional silvering is no improvement wherever there has been a proper first coating4 ,sometimes the operator is troubled with streaks or scum on the plate4 ,this may arise from three causes1 all of which experience must teach the experimenter to avoid2 first1 too great an excess of cyanide in the solution2 second1 a lack of silver2 third1 the current too strong4 ,another annoyance arises from the solution being dirty and the dirt collecting on the surface4 ,when this is the case1 the dirt is sure to come in contact with the surface of the plate as it is plunged into the solution1 and the result is a scum that it is difficult to dispose of4 ,this can be prevented only by frequent filtering4 ,one thing should always be borne in mind in electrotyping ,daguerreotype plates--that in order to secure a perfectly coated surface1 the plate should be perfectly cleaned4 ,in this point1 many who have tried the electrotype process have failed1 attributing their ill success to other than the proper cause4 ,,daguerreotypes ,,without ,,mercury4 ,the following process possesses some interest1 and is worthy a trial from operators4 ,m4 ,natterer1 of ,vienna1 discovered a process for obtaining proofs on iodized plates with the chloride of sulphur1 without the use of mercury4 ,a plate of silver is iodized in the usual manner1 and then placed on the top of a vessel six or eight inches high1 having at the bottom1 in a small cup1 a few drops of chloride of sulphur2 it should remain exposed to the action of the vapor until the sombre yellow color is changed to a red1 after which it is brought to a focus in the camera1 where it is exposed to the light in the camera1 for about the time necessary to produce an ordinary daguerreotype4 ,the plate is then taken out and examined in the camera by the light of a candle4 ,it often occurs that no trace of the image is as yet perceptible1 but if the plate is heated by placing over a spirit lamp the unprepared side1 or if left for some time in the dark1 or1 lastly1 if exposed only a few seconds to a weak1 dimmed light1 the positive picture then appears with all its shades4 ,of these three modes of bringing out the image1 the second is superior to the others4 ,,management ,,of ,,chemicals4 ,it is necessary1 first of all1 to know that you have a chemical which is capable of producing good results when in skillful hands4 ,for this reason it is best to prepare your own quick1 after some formula which is known to be good4 ,those quick-stuffs which contain chloride of iodine are noted for their depth of tone while they probably operate with less uniformity than those which are destitute of it4 ,for operating under ordinary circumstances1 especially with an inferior light1 probably no accelerator is more quick and sure than ,wolcott's4 ,it also produces a very fine1 white pleasing picture1 though lacking that depth of impression so much to be desired4 ,the dry quick operates with surety1 and its use is simple and easy1 producing an impression much like ,wolcott's4 ,for those having a good and permanent light1 however1 we would recommend a chemical giving more body to the impression4 ,there is a class of accelerators called sensitives1 claiming to work in from three to ten seconds1 which1 however1 will be found very little1 if any1 more sensitive than this4 ,we frequently work it with the ordinary coating in twelve and fifteen seconds4 ,the manner in which the sensitives are worked is by coating very light4 ,in this way1 a flat1 shallow picture is obtained in a few seconds2 and the same can be done with any of the more volatile quicks4 ,it is a fact not generally known1 that a plate coated in a light chemical room is more sensitive than when coated in darkness4 ,by admitting a free1 uniform light1 and exposing the plate to it a few seconds after coating1 then timing short in the camera1 a very light1 clear impression is obtained4 ,the time in the camera is reduced in proportion to the previous action of light4 ,the shades1 of course1 are destroyed1 and the tone injured2 still1 for taking children1 we have succeeded better by this method than by the use of 8sensitives40 ,the discovery of this principle was accidental1 while operating where the direct ray s of the sun1 entering the window just before sunset1 fell on the curtain of our dark room1 rendering it very light within4 ,the selection of iodine is not unimportant4 ,reject1 at once1 that which has anything like a dull1 black1 greasy appearance2 and select that which is in beautiful large crystalline scales1 of a purple color1 and brilliant steel lustre4 ,solarization1 and general blueness of all the light parts of the picture1 were formerly great obstacles to success1 though now scarcely thought of by first-class artists4 ,beginners in the art1 however1 are still apt to meet with this difficulty4 ,it is occasioned by dampness in the iodine box1 which causes the plate to become coated with a hydro-iodide of silver1 instead of the iodide4 ,the remedy is in drying your iodine4 ,if in summer1 you can open your box and set it in sunshine a few minutes2 or if in winter1 set it under a stove a short time4 ,the true method1 however1 is to dry it by means of the chloride of calcium4 ,it has such a remarkable affinity for water1 that a small fragment placed in the open air1 even in the dryest weather1 soon becomes dissolved4 ,take one or two ounces of this chemical1 heat it in the drying bath1 or in a hot stove1 to perfect dryness2 place it in a small glass toy dish1 or large watch crystal1 and set it in the centre of your iodine box4 ,take this out and heat to dryness every morning4 ,adopt this process1 and with your mercury at a high temperature1 you will never be troubled with blue pictures4 ,young operators are apt to impute all want of success in operating to their chemicals1 even though the cause is quite as likely to be elsewhere4 ,failure is quite likely to occur from dampness in the buffs1 or in the polish2 it is therefore necessary to be constantly on the guard in this quarter4 ,with a view to this1 always scrape your buffs with a dull knife1 or with one blade of your shears1 the first thing in the morning1 and after brushing them thoroughly1 dry them1 either in the sun1 by a stove1 or in the buff-dryer4 ,it is equally important that the polish and the brush should be kept dry4 ,want of success may arise from vapors of iodine or bromine in the camera box1 mercury bath1 or even in the buffs4 ,it is incredible how small a quantity of these vapors will affect the effect of light when coming in contact with the plate1 after or during the exposure in the camera4 ,it is therefore necessary to be cautious not to mix chemicals1 nor open your boxes or bottles in your room1 but take them out to do it4 ,never hurry the operation through from lack of confidence in the result4 ,the fact of anything being out of order1 forms no excuse for slighting the process4 ,if unsuccessful1 do not pursue the same course every trial1 but vary with a view to detect the cause of the difficulty4 ,in case of a long series of failures1 institute a regular course of investigation1 after this manner1 commencing where the trouble is most likely to occur3 #a4 ,are the plates well cleaned8 #b4 ,is the iodine dry8 ,if the impressions come out blue1 you may rest assured it is not4 ,take out the iodine1 wipe and dry the box1 and dry the calcium4 #c4 ,is the quick battery of the right strength8 ,if dry1 it must change the plate in from six to fifteen seconds4 ,if any of the chloride of iodine class1 it may vary from five seconds to a minute4 ,begin by coating light1 and increase on each trial1 observing the effect4 ,if the light side of the picture seems loth to come out1 and shows no contrast with the dark side1 it is to be inferred that your battery is too strong1 and must be reduced with water or set out in the open air for a few minutes1 with the lid off4 ,if working an old battery1 never renew very strong1 or it will work dark and heavy4 ,a battery1 to work well1 should be gradually losing strength1 but never gaining4 ,an old battery1 however1 may be quickened up and made to work well for some time1 by adding five of six drops of sulphuric acid1 repeating the quantity as often as necessary1 providing always that acid be not used in manufacturing the quick4 #d4 ,have the plates lost their sensitiveness by being many times exposed to mercury8 ,clean and burn them2 but if ,french plates1 burn light1 or you spoil them4 #e4 ,are the buff s dry and clean8 ,examine the plate critically after buffing to detect any appearance of scum or film on the surface4 ,if so1 the longer you buff the more it shows4 ,scrape and dry the buffs thoroughly4 #f4 ,is the mercury free from scum and dirt8 ,if not1 filter4 ,is it also far enough from the coating boxes8 ,should be at least three feet1 and kept covered4 #g4 ,is the mercury sufficiently heated8 ,this is important4 ,long exposure1 however1 will answer the same purpose4 #h4 ,are your lenses clean1 and in proper place8 #i4 ,are the tablets in focus with the ground-glass8 ,if you can attribute the failure to none of these1 mix a new box of some other kind of quick1 say the dry1 for instance4 ,if you fail in the same manner here1 take time1 wash your buffs1 overhaul all the chemicals1 and start anew4 ,do not be discouraged4 ,there is no day so dark but that the sun will shine again4 ,we will close with this brief summary of advice3 ,clean your plates4 ,keep everything dry4 ,keep the mercury hot4 ,follow these instructions carefully1 and you must succeed4 ,,hints ,,and ,,cautions4 ,first of all1 cleanliness should be observed4 ,when there is dust or dirt about your room1 particularly about the work-bench1 failures will be frequent2 for the smallest particles of rotten-stone1 when allowed to come in contact with the buffs1 will produce scratches on the surface of the plate1 which very much injures the operation1 and often causes failures4 ,dust flying about the room is injurious1 if allowed to fall on the plate1 either before or after it has been coated1 as it causes black spots which cannot be removed4 ,the polished plate should not be allowed to come in contact with a strong current of air1 for it tends to oxidize the surface4 ,breathing on the surface should also be avoided1 for the same reason4 ,the plate should1 in all cases1 be buffed immediately before using1 and not allowed to stand any length of time4 ,it should be held with the polished face downward4 ,it is always best that the plate should be of the same temperature of the atmosphere in the room4 ,keep the camera and mercury-bath perfectly free from the vapors of iodine and bromine2 for the presence of the slightest degree of either of the above will injure the impression in no small degree4 ,as a preventive1 let the camera be exposed to the sun or fire for a few minutes in the morning4 ,filter your mercury often1 to keep the surface free from film and dust4 ,the hyposulphite solution should be filtered through sponge every time it is used4 ,the direct rays of light must not enter the camera in conjunction with those reflected from the object2 or the picture will be veiled1 and the color of the plate changed to a thick green4 ,if the plate be iodized only to a light-yellow1 the result might be of a bluish or grey tinge3 and this is generally the case1 when the quick is new and strong1 and there is an excess of it on the plate1 and yet not enough to form the bromide iodide of silver2 in which case it would wholly spoil the impression4 ,your iodine will be found to operate more successfully1 when the time required for coating the plate does not fall short of fifteen seconds1 or exceed one minute4 ,too quick coating can be avoided by using less iodine in your box4 ,in the summer months1 when the weather is #hj deg4 and over1 one quarter of an ounce1 or even less1 will work to advantage4 ,,electrotyping4 ,i am indebted to ,mr4 ,j4 ,h4 ,fitzgibbons for the following process1 which he employed in producing the excellent specimens he exhibited at the ,crystal ,palace3 8,i shall endeavor to lay down in as comprehensive a manner as possible the method by which ,i have been enabled to produce the most satisfactory results4 ,i use a ,smee's battery 7another kind will do74 ,after filling the cell1 of common size1 nearly full with water2 add about quarter of an ounce of sulphuric acid4 ,mix this well1 and let it stand for about three hours1 or until the action of the battery becomes weak1 when it is in order to work with a very uniform action4 ,put one pound of sulphate of copper in one quart of water2 stir it until the sulphate of copper is all dissolved1 and then add one half ounce of sulphuric acid and a quarter of an ounce of nitric acid4 ,this solution1 well mixed1 should be filtered1 and it is ready for use4 ,it is very important that the solution should be kept clean1 clear1 and free from all foreign substance4 ,the above quantity of this solution will be found sufficient for electrotyping a dozen of the sixth-size plates4 ,when it is required to be strengthened1 it is only necessary to add a little of the sulphate of copper4 8,with the battery prepared as above1 and the solution of sulphate of copper in a vessel of proper dimensions to receive your plate1 connect the galvanic current1 and immerse the impressioned plate1 letting it remain until a thin film of copper has been formed1 then the battery can be strengthened1 and the impression will be of sufficient thickness to be removed in from eight to twelve hours4 ,an old ,daguerreotype plate attached to the opposite pole of the battery 7copper side towards the face of the plate to be electrotyped71 will answer the same purpose as the silver-plate4 8,the great difficulty in taking an electrotype impression1 and preserving the original1 has been attributed to the battery being too powerful4 ,i am led to believe from practice that the principal difficulty has been in the ,daguerreotype plate itself1 for if we use an impression that has been taken but a few days1 and taken in the usual way1 we will find it difficult to succeed without spoiling both the copy and original1 and so also with an old impression4 8,i have found the most certain method to be as follows3--,coat the ,daguerreotype plate as usual1 except use less of the accelerators1 the proportion of iodine coating being greater1 of course the time of exposure in the camera will be lengthened4 ,mercurialize it at about a temperature requiring to develop the image1 from six to eight minutes1 at least4 ,gilding the ,daguerreotype has much to do towards producing a good electrotype copy4 ,this should be done by applying a little heat1 and gilding very slowly1 giving a coating of gold with the greatest possible uniformity4 ,by this method1 ,i have been enabled to produce any number of proofs4 ,i have produced a dozen from one impression1 and it remains as perfect as when first taken4 8,by a little judgment and care the operator will be enabled to produce the electrotype copy of the ,daguerreotype plate without any difficulty4 ,the electrotype copy should be immediately put under a glass and sealed in the same manner as the ordinary ,daguerreotype40 ,,crayon ,,daguerreotypes4 ,this process is patented in the ,united ,states1 by ,j4 ,a4 ,whipple1 of ,boston1 and of course no honorable person will use it for his own benefit without purchasing a right4 ,a white back-ground is generally employed1 the object being to blur the lower portion of the plate1 leaving the head of the subject in relief4 ,every ,daguerreotypist is familiar with the fact that a motion of any body between the camera and the sitter will cause a 8blur40 ,cut a piece of thin paper and scallop it1 making a semicircle4 ,this is kept straight by means of a wire frame1 and it is to be moved in front of the lower part of the body of the sitter during the time of exposure of the plate in the camera4 ,develop over mercury as usual1 and the result will be a crayon ,daguerreotype4 ,another method is to have a wheel with a hole cut through it of a diameter of about #ab inches4 ,this hole is so cut as to leave teeth resembling those of a large saw4 ,this wheel is so arranged that it can be turned around1 which should be done during the time of exposure in the camera4 ,it must be placed between the camera and the sitter1 and at such a distance from the camera as to allow such proportion of the body of the sitter be seen upon the ground-glass as is desired4 ,it will be readily seen that by turning this wheel during the operation will produce the same result as the paper being moved in the other method4 ,the teeth make the 8blur40 ,the side of the wheel towards the camera may be black1 by which means the result will be a dark instead of a light border4 ,,illuminated ,,daguerreotypes4 ,this process is also patented1 and the remarks on the preceding subject will apply in this case4 ,the plate is prepared and exposed as in the usual method of the ,daguerreotype4 ,a white back-ground is employed4 ,let the head of the sitter come in the middle of the plate1 and before exposing it to the vapors of mercury1 put a small mat or diaphragm1 having a small hole through it1 over or directly on the surface of the plate4 ,this diaphragm should be bevelled1 and the bevel should be towards the surface of the plate2 this1 in order to prevent too sharp a line on the impression4 ,it will be readily seen that if an impressioned plate so covered is placed over the mercury1 it will be developed on such portions only as are exposed4 ,the principle is so familiar that further explanations are unnecessary4 ,,natural ,,colors ,,in ,,heliography4 ,this subject is worthy the attention of every operator4 ,the following process is so plain and easy of trial that any ,daguerreotypist can try it4 ,this is as given by ,mr4 ,james ,campbell1 and was published in ,humphrey's ,journal of the ,daguerreotype and ,photographic ,arts1 vol4 #e1 page #aa4 ,mr4 ,campbell has done much to further the process announced by ,m4 ,neipce1 and his experiments have proved highly successful4 ,the following is submitted as worthy of trial3 8,the proper preparation of the chloridated plate1 to enable it to receive colored impressions is an object of the first importance to those wishing to experiment on it1 and consequently requires particular notice4 ,the plate may be prepared by making it the positive pole of a battery1 and letting it at the same time be immersed in chlorine water4 ,the negative pole should be a slip of platinum4 ,all the colors may be produced from a plate so prepared if the chlorine and water are in the right proportions2 but generally one color or the other predominates1 according to the amount of chlorine in the liquid4 ,by adding the chlorides of strontian1 uranium1 potassium1 sodium1 iron1 or copper to the liquid1 various effects may be produced1 and these bodies will be found to produce the same color on the plate that their flame gives to alcohol4 8,the honor of this discovery is due to ,m4 ,neipce4 ,copper gives a variegated flame2 hence many colors may be impressed on a plate prepared with a solution of its chloride4 8,m4 ,neipce recommends a solution of the mixed chlorides of copper and iron1 and it is with these1 that ,i have been most successful4 ,as the chlorides of copper and iron are not much used in the arts1 they are not generally found for sale in the shops2 and it may be well to furnish those not much versed in chemistry with an easy method of preparing them4 8,they may be made directly from either metal by dissolving it in hydrochloric acid2 but they may be formed by a cheaper method1 and by which also the acid fumes are avoided4 8,sulphate of iron or copper1 or both together1 may be dissolved in water and then neutralized with common crude potash1 or its carbonate or bicarbonate--known commonly as pearl ash and saleratus4 ,if either of the latter be used1 there will be formed sulphate of potash and a carbonate of the metal used1 and there will also be a considerable effervescence of carbonic acid1 which will1 if care is not taken1 cause the mixture to run over the vessel4 ,after the copper or iron salt is neutralized1 which is known by its ceasing to effervesce1 the carbonate of the metal will settle slowly1 and will at first nearly fill the vessel4 ,the supernatant fluid1 which is sulphate of potash in solution1 may now be carefully poured off1 and its place filled with water2 this operation should be repeated several times until the water which passes off is tasteless4 ,the carbonate of the metal rapidly changes to an oxide by contact with the air1 and it will generally be found1 when it is sufficiently washed1 that it is at least half oxide4 ,on adding hydrochloric acid cautiously to the mixture1 a chloric of the metal will be formed1 and carbonic acid will be evolved from the remaining carbonate4 ,the chloride formed is soluble2 but as there are two chlorides of these metals1 and we wish to produce the one which contains the most chlorine1 it is best to add the acid cautiously until the solution is decidedly acid4 ,after filtering the solution1 it is fit for use2 and it should be preserved in well-stoppered bottles4 ,the water used should be rain or distilled water4 8,about one part of the mixed chlorides should be used to three or four of water4 8,the battery may be either ,smee's1 ,daniell's1 or ,grove's2 if of either of the former1 it should be of two series2 if of the latter1 one cup is sufficient4 8,the plate on being immersed in the liquid1 almost instantly takes a violet color4 ,it should be allowed to remain from two to five minutes1 according to the strength of the battery1 and until it becomes nearly black4 ,it should now be carefully washed1 and afterwards heated over a spirit lamp until it takes a cherry-red color1 and it is then ready for exposure in the camera4 ,before speaking of exposing the plate1 it may be well to speak of some difficulties which the inexperienced operator may find in preparing it4 ,if the battery is not in good order1 and a sufficient current is not passed through the solution1 the plate will become coated--and apparently almost as well as when the battery is working well--but on exposure it will give a negative picture1 and but little colored2 while if the battery is in good order1 the impression is invariably positive4 8,sometimes on heating the plate after washing1 the surface is covered with spots or assumes a variegated appearance4 ,this indicates that the solution is impure1 or that the plate have not been thoroughly washed and are still contaminated with the soluble chlorides which are contained in the solution4 8,from the fact that the plate if prepared with positive electricity gives a positive picture1 while it prepared otherwise it gives a negative1 it is evident that electricity plays an important part in this process4 ,the same is true to some extent with the compounds formed with iodine1 bromine1 and fluorine4 8,on heating the plate1 the brown coating of chloride melts into a translucent enamel1 and the heat should be withdrawn when a cherry-red color is produced4 ,it the heat is continued longer1 the plate assumes a lighter color1 and becomes less sensitive2 and the enamel will finally scale off4 ,to produce a picture by the ordinary process of ,m4 ,neipce1 unaccelerated1 it should be exposed for from three to five hours to sunlight in the camera1 though pictures may be procured by contact1 in from fifteen to thirty minutes40 ,,multiplying ,,daguerreotypes ,,on ,,one ,,plate4 ,i have produced some interesting specimens of the ,daguerreotypic art1 by exposing in the camera only a portion of the sensitive plate to the action of light4 ,when on the exposed portion an image is formed1 then taking the tablet into the dark room1 change ends and expose the sensitive portion1 and produce another image1 developing as usual4 ,this plan is adapted for taking likenesses for lockets4 ,two images can be presented as sitting side by side1 by covering half the plate with black paper1 and exposing as before4 ,in this manner we have been enabled to surprise persons by exhibiting their portrait on the same plate with a stranger's4 ,daguerreotypists must be cautious in practicing this1 as it might not be agreeable to the parties whose likenesses are together1 by the above process4 ,it is impossible to produce an impression without a line being seen where the edge of the paper prevented the operation of the light4 ,i have recently seen a fine specimen produced by another plan1 which far exceeds the above1 there being no line1 or any peculiarity denoting two exposures4 ,the specimen referred to1 was a gentleman represented on one plate by two full length portraits4 ,this was produced by using a black velvet for the background4 ,the plate was exposed sufficient time to produce one impression1 and then the gentleman assumed another position1 and is repeated as looking at himself4 ,from the fact that the time required to develop black velvet being so much longer than that for producing a portrait1 we are enabled to produce the above interesting results4 ,,deposit ,,in ,,gilding4 ,regarding specks from bad water1 ,i would remark that gilding should be made only with distilled water4 ,thus made1 it produces very little deposit1 even by long keeping4 ,it therefore preserves its original strength1 and works with great uniformity4 ,every grain of deposit contains at least #g-aj its weight of gold1 easily discoverable by the blowpipe4 ,such gilding is continually deteriorating1 which with good chloride and distilled water may be prevented4 ,distilled water should also be used for the hyposulphite4 and for cleaning plates4 ,any good1 clear water may be afterwards used for washing off1 with equally good results4 ,i am very rarely troubled with specs1 and deem this as the main reason4 ,with a portable still attached to a cooking stove1 ,i obtain half a gallon of water per hour1 and with very little trouble4 ,a small tin retort or still connected with a ,leibig's condenser1 would not add much to the 8traps0 of the travelling operator1 and save him many a disreputable specimen4--,t4 ,j4 ,,bailey4--,humphrey's ,journal4 ,,practical ,,hints ,,on ,,the ,,daguerreotype4 ,the following is from ,humphrey's ,journal1 vol4 #e1 and from the pen of ,dr4 ,,wm4 ,,harrington1 one of the most able writers upon the subject of the ,daguerreotype in this country3 ,,the ,,cause ,,of ,,the ,,difficulty ,,that ,,sometimes ,,occurs ,,to ,,prevent ,,the ,,production ,,of ,a ,,clear ,,impression ,,upon ,a ,,daguerreotype ,,plate4 ,beyond all doubt this is traceable to dampness4 ,truly this is not a new thought2 but where does this dampness come from8 ,how does it originate1 and where is it located8 ,generally it has been referred to a point entirely remote from its real location4 ,this dampness exists particularly upon the surface of the plate2 is obviously derived immediately from the atmosphere2 and is owing to a certain relative temperature of the plate with the hygrometric condition of the atmosphere4 ,whenever this relation exists between the plate and atmosphere1 a precipitation of moisture takes place upon the surface of the plate1 which render all efforts at polishing impracticable4 ,this interference is not confined to the buffing operation alone1 but sometimes is discoverable even in the ordinary process of scouring4 ,every one at all experienced in this art will remember that it is not always an easy matter for him1 by scouring1 to bring his plate to the desired lustre4 ,all his efforts become unavailing2 the more he rubs1 the duller the surface of his plate appears2 and although he renews his cotton repeatedly1 still he is obliged to content himself with an unsatisfactory finish4 ,this relative condition is not confined to any particular season of the year1 nor to any certain thermometric temperature2 but may occur in summer as well as in winter2 the weather being warm or cold1 wet or dry1 clear or cloudy1 raining or shining4 ,under any of these circumstances1 if the relation of the plate and atmosphere be such as to invite upon the plate a precipitation of humidity from the atmosphere1 the prospect of producing a clear impression is quite problematical4 ,it is reasonable to expect this occurrence from the fact that metal is a good radiator1 and radiation reduces the temperature of a metallic body below that of the atmosphere4 ,consequently1 if this relative condition happens1 the result will be as ,i have stated4 ,bodies may be colder than the atmosphere and yet derive no moisture from it2 while at the same time the driest atmosphere is not devoid of moisture1 but will part with it under certain conditions4 ,assuming for granted that this relative condition between the plate and atmosphere1 disposing the former to receive the humidity of the latter1 constitutes the great obstacle the operator has to contend with in producing1 a clear proof upon the plate1 the remedy naturally suggests itself1 and is very simple4 ,it consists in merely heating the plate above the temperature of the atmosphere1 previous to polishing1 and retaining that temperature during the operation4 ,various measures might be devised to effect the desired object2 one of which consists of a sheet-iron box1 heated from the inside by a spirit-lamp1 upon the top of which are to be kept the plates ready to undergo the process of being polished2 the blocks of the swing or any other vice2 or the iron bed belonging to ,lewis's vice4 ,in cold weather1 when it is necessary to keep a fire in the preparation room1 all of the above may be so arranged in the vicinity of the fire as to receive the requisite degree of heat for the purpose specified4 ,this part of the subject1 however1 is left entirely for the ingenuity of the operator4 ,no matter by hat means he accomplishes the object2 all that is required is to heat the plate above the temperature of the atmosphere and retain that heat during the process of polishing4 ,since the adoption of this method1 in connection with my partner1 ,t4 ,j4 ,dobyns1 even in this humid climate of ours1 when everything in the room is dripping with moisture1 it has been attended with invariable success4 ,,choice ,,of ,,plates1 ,,etc4 ,in the great catalogue of complaints made by operators1 none is more common than that alleged against the quality of plates in general use4 ,although the greatest diversity of opinion exists upon this subject1 nevertheless the plates of every manufactory share in this universal condemnation4 ,to be sure it cannot be denied but that this necessary article of utility in the photographic art has undergone a sad deterioration in quality owing to the increasing demand and great reduction in price--the plates of the present day being by no means so heavily coated with silver as formerly--but the complaint alluded to is not predicated so much upon the thinness of silver as upon a mysterious something which has conferred upon the plates the epithet of not good4 ,that this complaint is in a great measure groundless appears evident from the fact that while1 with the same brand of plates one operator can work successfully1 another encounters the greatest difficulty2 while one is able to produce beautifully clear and altogether satisfactory results1 the other labors under the troublesome annoyance of innumerable specks1 large dark insensitive patches and brown map-like portions1 together with divers other blemishes1 sufficient to prevent him from obtaining anything like a tolerable impression4 ,from this wide difference in the results of the two operators using identically the same article1 it is but reasonable to conclude that the complaint is founded in error2 while the inference is no more than just1 that the fault may be traced to a want of practical skill on the part of the complaining operator himself2 rather than to the inferior quality of the plates4 ,the question1 then1 whether the plates are unfit for use1 or whether those who pronounce them so understand how to use them1 appears to be satisfactorily answered4 ,it therefore becomes a matter worthy of investigation1 to ascertain what superior judgment and skill one operator possesses over another which enable him to work successfully a quality of plate1 pronounced by the other entirely useless4 ,suppose we make a critical examination of one of the repudiated plates4 ,from its external appearance we have little hesitation in pronouncing it to be ,french2 indeed1 this presumption is strongly corroborated by the fact that it is ornamented upon one of its corners with a brand to designate the manufactory from which it emanated4 ,upon close inspection we cannot fail to notice a striking peculiarity upon the surface2 the roughness is very remarkable2 the planishing hammer has left amazingly visible indications of its busy work4 ,one would suppose the manufacturer intended the surface of the plate to represent the undulations of the sea1 instead of that smooth and level character so strongly recommended by ,m4 ,daguerre4 ,such a plate necessarily requires at the hand of the operator considerable labor before the surface is in a proper condition to receive a suitable polish from the buffer4 ,the least reflection in the world should teach any one that so long as the undulatory character continues upon the surface of the plate1 it is in a very imperfect condition for buffing1 because the buffer cannot touch every point equally2 the elevated portions alone receiving a high degree of polish while the depressed portion1 from their roughness acting as nuclei1 gather dust1 rouge1 and other foreign bodies1 so detrimental to sensitiveness4 ,the secret of the superior judgment and skill of one operator over another1 is intimately connected with this point3 his success depends very much upon the first process of cleaning the plate4 ,let us examine the manipulation of the complaining operator4 ,he takes one of these plates and gives it a careful scouring with rotten-stone and alcohol or any other liquid preferred for this part of the operation--that is1 he gives it what he terms a careful scouring--very gently indeed because1 from the frequent trials he is in the habit of making in the camera1 he fears he will rub the silver entirely away before he succeeds in obtaining a good impression4 ,the dark patches1 specks1 and granular appearance resulting entirely from the unevenness of the surface of the plate1 look like copper to him1 and he is surprised that he should have rubbed away the silver so soon1 particularly by such delicate handling4 ,the judgment and experience of the successful operator1 however1 teach him that scouring injures a plate less than buffing4 ,he knows that unless the hammer marks be obliterated1 he cannot by the buffer produce a surface of uniform polish and sensitiveness1 without which a fair proof is extremely doubtful2 he knows that the time employed in the preliminary operation of cleaning the plate properly is economy4 ,there is a style of ,french plates in the market1 denominated heavy1 which are truly excellent1 if properly managed4 ,much patience1 however1 is required to remove the marks of the hammer2 but with tripoli and alcohol the surface is readily cut down1 and the plate is then susceptible of a beautiful black lustre by polishing with the buffer4 ,the complaining operator could not succeed by his own method with one of the plates2 he would encounter all manner of clouds and other unaccountable phenomena2 he would imagine this plate entirely worn out before it was half cleaned1 and soon fix in his own estimation the reputation of the heavy plate4 ,in making a choice of plates1 therefore1 it would appear to be a matter of perfect indifference with an experienced operator what kind he would use1 except so far only as the labor required in cleaning them was to be taken into consideration4 ,the distinction between a scale plate1 a ,scovill ,no4 #a1 ,s4 ,f41 heavy ,a1 star1 crescent1 eagle1 or any other brand1 consists in the superior finish of some1 and the thinness of the silver in the cheaper qualities4 ,consequently1 let the complaining operator but employ the diligence inculcated in this article1 to clean his plate thoroughly1 so as to bring it to a perfectly even and level surface1 and he will seldom be troubled with specks1 clouds1 dark patches1 and the host of other obstacles which heretofore have tormented him4 ,,chapter ,,vi4 ,,an ,,account ,,of ,,wolcott ,,and ,,johnson',s ,,early ,,experiments1 ,,in ,,the ,,daguerreotype4 ,,by ,,john ,,johnson4 ,from ,humphrey's ,journal1 vol4 ii #ahea ,as a general thing1 however perfect any invention may be deemed by the inventor or discoverer1 it falls to the lot of most1 to be the subject of improvement and advancement1 and especially is this the case with those new projects in science which open an untrodden field to the view of the artisan4 ,such has been1 in an eminent degree1 the case with the discovery first announced to the world by ,mons4 ,jean ,jaques ,claude ,daguerre1 of ,paris1 in the year #ahci1 and which excited unbounded astonishment1 curiosity and surprise4 ,it may be questioned had any other than ,daguerre himself discovered a like beautiful combination1 whether the world would have been favored with details exhibiting so much care1 patience and perseverance as the ,daguerreotype on its introduction4 ,shortly after1 these details reached the ,united ,states1 by ,professor ,s4 ,f4 ,b4 ,morse1 of ,new ,york1 who was1 at the time of the discovery1 residing in ,paris4 ,by this announcement1 the whole scientific corps was set in operation1 many repeating the experiments1 following carefully the directions pointed out by ,daguerre1 as being necessary to success4 ,among the number in the ,united ,states1 was ,alexander ,s4 ,wolcott 7since deceased7 and myself2 both of this city4 ,on the morning of the #fth day of ,october1 #ahci1 ,i took to ,a4 ,wolcott's residence1 a full description of ,daguerre's discovery1 he being at the time engaged in the department of ,mechanical ,dentistry1 on some work requiring his immediate attention1 the work being promised at #b ,p4,m4 that day2 having1 therefore1 no opportunity to read the description for himself 7a thing he was accustomed to do at all times1 when investigating any subject74 ,i read to him the paper1 and proposed to him that if he would plan a camera 7a matter he was fully acquainted with1 both theoretically and practically71 ,i would obtain the materials as specified by ,daguerre4 ,this being agreed to1 ,i departed for the purpose1 and on my return to his shop1 he handed me the sketch of a camera box1 without at all explaining in what manner the lens was to be mounted4 ,this ,i also undertook to procure4 ,after #b1 ,p4,m41 he had more leisure1 when he proceeded to complete the camera1 introducing for that purpose a reflector in the back of the box1 and also to affix a plate holder on the inside1 with a slide to obtain the focus on the plate1 prepared after the manner of ,daguerre4 ,while ,mr4 ,wolcott was engaged with the camera1 ,i busied myself in polishing the silver plate1 or rather silver plated copper2 but ere reaching the end preparatory to iodizing1 ,i found ,i had nearly or quite removed the silver surface from off the plate1 and that being the best piece of sliver-plated copper to be found1 the first remedy at hand that suggested itself1 was a burnisher1 and a few strips were quickly burnished and polished4 ,meantime1 the camera being finished1 ,mr4 ,wolcott1 after reading for himself ,daguerre's method of iodizing1 prepared two plates1 and placing them in the camera1 guessed at the required time they should remain exposed to the action of the light2 after mercurializing each in turn1 and removing the iodized surface with a solution of common salt two successful impressions were obtained1 each unlike the other6 ,considerable surprise was excited by this result1 for each plate was managed precisely like the other4 ,on referring to ,daguerre1 no explanation was found for this strange result2 time1 however1 revealed to us that one picture was positive1 and the other negative4 ,on this subject ,i shall have much to say during the progress of the work4 ,investigating1 the cause of this difference occupied the remainder of that day4 ,however1 another attempt was agreed upon1 and the instruments1 plates1 etc41 prepared and taken up into an attic room1 in a position most favorable for light4 ,having duly arranged the camera1 ,i sat for five minutes1 and the result was a profile miniature 7a miniature in reality17 or a plate not quite three-eighths of an inch square4 ,thus1 with much deliberation and study1 passed the first day in ,daguerreotype--little dreaming or knowing into what a labyrinth such a beginning was hastening us4 ,description of apparatus represented on pages #aib and #aii3 ,a4--,the ,box--about #d inches long by about #b outside diameter4 ,b4--,the ,reflector soldered to a brass screw1 and mounted in the rear of the box4 c4--,the slide to regulate the focus to the plate holder4 d4--,the standard to the plate holder screwed to the slide4 f4--,the plate-holder frame having two small ledges1 99 991 for the plate to rest upon4 #aib g4--,the plate resting upon the ledge41 99 991 and kept against the frame by the spring h4 ,the plates used were about #c_/h of an inch square4 ,a4--,the window with the sashes removed4 ,b and ,c 7p4 #aii7 are large looking-glasses mounted as plain reflectors1 the lower one ,c having rotary motion upon the saddle1 resting upon the sill of the window in order to direct the rays of the sun upon the reflector ,b1 at any hour of the day--the vertical motion of the reflector ,c being necessary1 the sun varying in altitude so much during the hours most favorable to the production of portraits4 ,the reflector ,c was #aic kept up to the required position by the handle lever1 upright post and bolts4 ,reflector ,b was hinged at its upper end at the top of the window frame1 the only motion being necessary was that which would reflect upon the sitter the incident rays from reflector ,c--the reflector ,b being kept at the required angle by the connecting lever m1 etc4 ,suitable back-grounds were placed behind the sitter4 ,illustration3 ,fig4 #ab ,the reflector ,b and ,c1 had frequently to be renewed1 the heat of the sun soon destroying their brilliance or power of reflecting1 light1 before renewing them1 however1 we resorted to the springing of them1 by which means their power was increased for a period4 ,the camera or reflecting apparatus1 invented by ,mr4 ,wolcott1 was1 from the nature of the case1 better adapted at that day to the taking of portraits from life1 than any other instruments4 ,after carefully examining the camera described by ,daguerre1 and the time stated as necessary to produce action for an image1 it became evident to the mind of ,mr4 ,wolcott at once1 that more light could be obtained 7as the field of view required was not large7 by employing a reflector of short focus and wide aperture1 than from a lens arrangement1 owing to spherical aberration and other causes4 ,many experiments having been tried with the small instrument figured 7p4 #aii71 a reflector for taking portraits from life was determined on1 having eight inches diameter1 with twelve inches focal distance for parallel rays2 this was to admit plates of two inches wide by two and a half long ,mr4 ,wolcott having on hand reflectors of the right diameter1 for ,newtonian telescopes1 of eight feet focal distance1 resolved 7as it was a matter of experiment7 to grind down or increase the curve for the focal distance before named--this required time4 ,in the mean time1 many plans were pursued for making good plates1 and the means of finishing1 them4 ,as the completion of the large reflector drew to a close1 our mutual friend1 ,henry ,fitz1 ,jr41 returned from ,england1 whither he had been on a visit1 and when he heard what we were about1 kindly offered his assistance2 he being well versed in optics1 and having been before engaged with ,mr4 ,wolcott1 in that and other business is offer was gladly accepted--,mr4 ,wolcott himself having frequent engagement2 to fill as operator in the details of mechanical dentistry4 ,thus1 by the aid of ,mr4 ,fitz1 the reflector was polished1 and experiments soon after tried on plates of two by tow and a half inches1 with tolerable success4 ,illness on my part quite suspended further trial for nearly four weeks4 ,on my recovery1 early in ,january1 #ahdj1 our experiments were again resumed with improved results1 so much so as to induce ,mr4 ,wolcott and myself to entertain serious thoughts of making a business of the taking of likenesses from life1 intending to use the reflecting apparatus invented by ,mr4 ,wolcott1 and for which he obtained ,letters ,patent1 on the #hth day of ,may1 #ahdj4 ,up to ,january #ast1 #ahdj1 all experiments had been tried on an economical scale1 and the apparatus then made1 was unfit for public exhibition2 we resolved to make the instruments as perfect as possible while they were in progress of manufacture4 ,experiments were made upon mediums for protecting the eyes from the direct light of the sun1 and also upon the best form and material for a back-ground to the likenesses4 ,the length of time required for a 8sitting10 even with the reflecting apparatus1 was such as to render the operation anything but pleasant4 ,expedients were ever ready in the hands of ,wolcott3 blue glass was tried and abandoned in consequence of being1 at that time1 unable to procure a piece of uniform density and surface3 afterwards a series of thin muslin screens secured to wire frames were prepared as a substitute for blue glass4 ,the objections to these screens1 however1 were serious1 inasmuch as a multiplication of them became necessary to lessen the intensity of the light sufficiently for due protection to the eyes1 without which1 the likenesses1 other than profiles1 were very unpleasant to look upon4 ,most of the portraits1 then of necessity were profiles formed upon back-grounds1 the lighter parts relieved upon black1 and the darker parts upon light ground2 the back-ground proper being of light colored material with black velvet so disposed upon the light ground1 this being placed sufficiently far from the sitter1 to produce harmony of effect when viewed in the field of the camera4 ,other difficulties presented themselves seriously to the working of the discovery of ,daguerre1 to portrait taking--one of which was the necessity for a constant and nearly horizontal light1 that the shaded portions of the portrait should not be too hard1 and yet1 at the same time1 be sufficiently well developed without the 8high light0 of the picture becoming overdone1 solarized or destroyed4 ,in almost all the early specimens of the ,daguerreotype1 extremes of light and shade presented themselves1 much to the annoyance of the early operators1 and seriously objectionable were such portraits4 ,to overcome this difficulty1 ,mr4 ,wolcott mounted1 with suitable joints1 upon the top of his camera1 a large looking-glass or plane reflector1 in such a manner that the light of the sun 7as a strong light was absolutely necessary71 when falling upon the glass could be directed upon the person in an almost horizontal direction4 ,early in ,february1 #ahdj1 ,mr4 ,johnson1 ,sen41 7since deceased7 sailed for ,europe with a few specimen likenesses taken with the instruments completed as above1 with the intention of patenting the invention4 ,on his arrival a joint arrangement was effected with ,mr4 ,richard ,beard1 of ,london1 in patenting and working the invention in ,england4 ,up to ,february1 #ahdj1 but few friends had been made acquainted with the progress of the art in the hands of ,mr4 ,wolcott and myself4 ,from time to time reports reached us from various sources of the success of others1 and specimens of landscapes1 etc41 were exhibited at ,dr4 ,james ,r4 ,chilton's laboratory1 in ,broadway1 much to the gratification of the numerous visitors and anxious expectants for this most wonderful discovery4 ,dr4 ,chilton1 ,professor ,j4 ,j4 ,mapes1 ,professor ,j4 ,w4 ,draper4 ,professor ,s4 ,f4 ,b4 ,morse1 all of this city2 ,mr4 ,cornelius1 ,dr4 ,goddard and others of ,philadelphia2 ,mr4 ,southworth1 ,professor ,plumbe1 and numerous others were early in the field2 all1 however1 using the same description of camera as that of ,daguerre1 with modification for light1 either by enlargement by lens and aperture for light1 or by shortening the focal distance4 ,at a conversational meeting of the ,mechanics' ,institute1 ,professor ,j4 ,j4 ,mapes being present1 a question was asked if any one present could give information relative to portraiture from life by the ,daguerreotype4 ,mr4 ,kells1 a friend of ,mr4 ,wolcott and a scientific and practical man 7since deceased71 at once marked out upon the black-board1 the whole as contrived by ,mr4 ,wolcott4 ,this gave publicity to the invention of ,mr4 ,wolcott4 ,shortly after1 ,professor ,mapes1 ,dr4 ,chilton1 and many others1 sat for their portraits1 and were highly gratified4 ,professor ,morse also came and proposed to ,mr4 ,wolcott to join him in the working of the invention1 etc4 ,from this time much interest was manifested by our friends in our progress4 ,rooms were obtained in the ,granite ,buildings1 corner of ,broadway and ,chambers street1 and fitted for business4 ,the rooms being small1 it was soon found impracticable to use the arrangement of looking-glass1 as previously spoken of2 a new plan became necessary1 to introduce which1 the sashes were removed1 #aii and two large looking-glasses were mounted in proper frames1 thus3-- ,illustration3 ,fig4 #ac ,just in front1 and between the sitter and #bjj the reflector1 upon a proper stand1 were used those paper muslin screen before described2 also screens of tissue paper4 ,these screens1 however1 when they were used1 required so much time for a sitting1 that some other medium1 as a protection to the eyes1 became absolutely necessary4 ,the most plausible thing that suggested itself was blue glass2 but1 as this could not be found1 numerous were the expedients proposed by the friends of the art1 who from time to time visited our rooms4 ,at the suggestion of ,professor ,mapes 7who is ever ready to assist those in perplexity71 a trough of plate glass s1 about twenty-eight inches square in the clear1 and from three to four inches thick1 was filled with a solution of ammonia sulphate of copper1 and mounted on the frame as in the sketch1 which1 for a time1 answered extremely well2 soon1 however1 decomposition of this solution became apparent from the increased length of time required for a sitting1 although to the eye of an observer1 no visible cause for such long sittings could be pointed out4 ,professor ,mapes being appealed to1 suggested that to the above solution a little acid be added which acted like a charm--shortening the time for a sitting from six1 eight1 or ten minutes to that of about one4 ,decomposition1 however1 would go on by the action of light and heat through the solution4 ,new solutions were tried1 when the whole were finally abandoned as being1 too uncertain and troublesome4 7,the reflecting apparatus ,r1 was placed upon the stand as in the sketch1 with a wedge for elevating the camera1 between it and the table1 to obtain the image properly upon the plate47 ,a quantity of blue window glass was next obtained1 and holes drilled through the corners of it1 and several sheets were wired together to increase the size1 and1 when complete1 was suspended from the ceiling in its proper place1 and so arranged that when a person was sitting1 this sheet of glass could be moved to and from1 the object of which was to prevent shadows on the face of the sitter produced from the uneven surface of the glass4 ,this latter contrivance was used until a perfect plate of glass was procured4 ,the number of persons desirous of obtaining1 their miniatures1 induced many to entertain the idea of establishing themselves in the ,art as a profession1 and numerous were the applications for information2 many persons paying for their portraits solely with the view of seeing the manner of our manipulations1 in order that they might obtain information to carry on likeness-taking as a business4 ,the reflecting camera being a very troublesome instrument to make1 and difficulties besetting us from every source1 but little attention could be given to teaching others2 and1 indeed1 as the facts seemed to be at this time1 we knew but little of the necessary manipulations ourselves4 ,in course of time1 several established themselves4 ,the first one1 after ourselves1 who worked the discovery of ,daguerre for portrait taking in this city1 was a ,mr4 ,prosch2 followed soon after by many others1 in almost all cases copying the reflecting arrangement for light1 as figured above1 many using it even after we had long abandoned that arrangement for a better one4 ,innumerable obstacles to the rapid advance of the daguerreotype1 presented themselves almost hourly1 much to the annoyance of ourselves1 and those dependent upon our movements for their advancement4 ,among the most difficult problems of the day1 was the procuring of good plates4 ,messrs4 ,corduran ,co4 were among the first to supply the trade2 at that early day1 however1 it was a very rare thing1 to be able to procure an even perfect surface1 from the fact that a pure surface of silver could scarcely be obtained1 the manufacturers deeming it too much trouble to prepare silver plated copper with pure silver--the result was1 that in attempting to polish perfectly such plated metal as could be procured1 the plates would become cloudy1 or colored in spots1 from the fact of having more or less alloy1 according as more or less of the silver surface was removed in polishing the plate fit for an impression4 ,to explain more clearly1 it was the practice of most silver platers to use an alloy for silver-plating4 ,in the reduction of the ingot to sheet metal1 annealing has to be resorted to1 and acid pickles to remove oxides1 etc4 ,the number of times the plated metal is exposed to heat and acid in its reduction to the required thickness1 produces a surface of pure silver4 ,the most of this surface is1 however1 so rough as to be with difficulty polished1 without in places removing entirely this pellicle of pure metal1 and exposing a polished surface of the alloy used in plating4 ,whenever such metal was used1 very unsightly stains or spots frequently disfigured the portraits4 ,the portrait1 or portion of it1 developed upon the pure silver1 being much lighter or whiter than that developed upon the alloy2 it therefore appeared that the purer the silver1 the more sensitive the plate became4 ,accordingly1 we directed ,messrs4 ,scovills1 of ,connecticut1 to prepare a roll of silver-plated metal1 with pure silver2 it fortunately proved to be a good article1 but1 unfortunately1 a pound of this metal 7early in #ahdj7 cost the round sum of #i4 ,like descriptions of metal1 the same gentlemen would be glad to furnish1 at this time1 for #d4 ,soon after this1 some samples of ,english plated metal1 of a very superior quality1 came to our possession1 and relieved us from the toil of making and plating one plate at a time1 an expedient we were compelled to resort to1 to command material to meet the pressing demands for portraits4 ,having it now in our power to obtain good plated metal1 a more rapid mode of polishing than that recommended by ,daguerre was attempted as follows3 ,this metal was cut to the desired size1 and having a pair of 8hand rolls0 at hand1 each plate1 with its silvered side placed next to the highly polished surface of a steel die1 was passed and repassed through the rolls many times1 by which process a very smooth1 perfect surface was obtained4 ,the plates were then annealed1 and a number of plates thus prepared were fastened to the bottom of a box a few inches deep a foot wide1 and eighteen inches long2 this box was placed upon a table and attached to a rod connected to the face plate of a lathe1 a few inches from its centre1 so as to give the box a reciprocating motion4 ,a quantity of emery was now strewn over the plates1 and the lathe set in motion4 ,the action produced wag a friction or rubbing of the emery over the surface of the plates4 ,when continued for some time1 a greyish polish was the result4 ,linseed1 when used in the same manner1 gave us better hope of success1 and the next step resorted to was to build a wheel and suspend it after the manner of a grindstone4 ,the plates being secured to the inner side of the wheel or case1 and as this case revolved1 the seeds would constantly keep to the lower level1 and their sliding over the surface of the plates would polish or burnish their surfaces4 ,this1 with the former1 was soon abandoned2 rounded shots of silver placed in the same wheel were found not to perform the polishing so well as linseed4 ,buff-wheels of leather with rotten-stone and oil1 proved to be far superior to all other contrivances2 and1 subsequently1 at the suggestion of ,professor ,draper1 velvet was used in lieu of buff leather1 and soon superseded all other substances1 both for lathe and hand-buffs1 and ,i would add1 for the benefit of new beginners that those who are familiar with its use1 prefer cotton velvet4 ,the only requisite necessary is1 that the buffs made of cotton velvet should be kept dry and warm4 ,the greater number of operators1 with whose practice ,i am familiar1 use1 for polishing plates1 prepared tripoli1 imported from ,france1 or ,browne's rotten-stone4 ,the former of these articles is very objectionable1 inasmuch as there is no positive certainty of being enabled to procure or make the article of uniform grit--the nature of the substance rendering1 it impossible to reduce it to varying degrees of evenness1 by the well known process of washing1 for that purpose1 and the burning of rotten-stone changes its chemical nature somewhat1 at the same time rendering1 this invaluable article harsh and gritty4 ,and especially1 no reliance can be placed upon burned rotten stone if purchased from those who do not give very great attention and care to its preparation2 and the same remarks apply to rouge4 ,the best article for polishing ,daguerreotype plates is rotten-stone1 such as can be procured in any town1 prepared after the following manner3 ,procure1 say half a dozen wide-mouthed bottles1 of suitable dimensions1 numbering each from one to six4 ,put into ,no4 #a about half a pound of rotten-stone1 and nearly fill the bottle with water4 ,then1 with a proper stick or spatule1 mix well the rotten-stone and water2 after which1 let ,no4 #a rest for1 say one minute1 then carefully pour off into bottle ,no4 #b 7or1 what would be better1 draw off by a syphon7 as much of the floating particles of rotten-stone as is suspended in the water4 ,again fill bottle ,no4 #a with water1 agitate it as before1 and decant it to bottle ,no4 #b1 care being taken to draw off only the suspended particles of rotten-stone4 ,when a sufficient quantity of washings from bottle ,no4 #a is collected into bottle ,no4 #b1 a similar process must be gone through1 as above stated1 for ,no4 #a2 the difference being in the care required1 and in the time allowed between the stirring or mixing the rotten-stone and water4 ,the floating particles of rotten-stone1 after four minutes' subsiding1 will be found fine enough for the finest ,daguerreotype polishing required4 ,a quantity of such washings may be collected in a large bottle1 and allowed to stand a few hours1 when all the rotten-stone will have settled4 ,the water may be poured off and the rotten-stone put into an evaporating dish1 and while being dried1 must be constantly stirred to obtain an impalpable powder4 ,further washings may in like manner be resorted to for finer qualities of rotten-stone4 ,in my practice1 ,i have used the articles at two and four minutes' settling1 and occasionally have prepared it after standing for eight minutes4 ,so fine a quality as this1 however1 is seldom required4 ,in using1 rotten-stone1 ,i mix with it1 for polishing1 fine olive oil1 until ,i obtain a thin paste--and the best of all methods for polishing 7well planished7 ,daguerreotype plates1 is one like that used for glass by lens polishers2 that is1 by using a disc or buff-wheel1 and having1 a suitable holder by which to secure the plate1 and then by pressing the plate against the revolving buff1 well saturated with the mixed oil and rotten-stone1 a very good surface is obtained4 ,a quantity of plates may be prepared in this way1 and all the adhering oil1 etc41 may be removed by a clean hand1 or lathe buff1 after which each plate must be heated to the point necessary to burn off the remaining oil great care being required not to overheat the plate4 ,a very slight excess of temperature will at once destroy all the polish previously obtained4 ,the test for ascertaining the right temperature is at hand2 the adhering oil will be driven from the plate in the form of smoke when the right temperature is reached4 ,the moment the smoke ceases to rise from the plate1 the heat must be removed1 and the plate quickly cooled upon a piece of iron4 ,a quantity of plates thus prepared may be kept on hand for any required time1 and the labor of one minute1 with a lathe or hand-buff with dry charcoal1 or rather1 prepared lampblack1 will perfectly polish the surface ready for indexing1 etc4 ,this lampblack also requires some care in preparing4 ,take a small-size crucible1 properly temper it by a slow fire1 that it may not be cracked after which1 fill it with common lampblack1 cover it over with a piece of soap-stone1 and again replace it in the fire4 ,build a good hard coal fire around it continue the heat for two or three hours1 being careful not to raise the cover till the crucible be quite cold4 ,pulverize when using it4 ,it is very desirable to keep this lampblack dry and warm4 ,some operators use much rouge ,i would recommend the above in preference2 but those who feel that they cannot dispense with the use of rouge1 had better try a large addition of prepared lampblack to a small one of rouge1 as this latter article1 unless great pains be taken in its preparation1 will adhere and work itself into the body of the surface1 so that it cannot be removed therefrom2 and ,i have seen many specimens of ,daguerreotype very much injured in effect from this rouge tint disseminated throughout their shaded features1 at the same time that the whole general effect of such pictures is that of a want of life4 ,it is true that with the use of rouge a very high degree of polish may be obtained1 but probably not higher than can be produced with many other substances of a less objectionable nature4 ,from the announcement of the discovery by ,daguerre to the beginning of the year #ahdj1 ,i am not aware of any attempt to lessen the time for the action of an image1 or an impression1 other than that of the reflecting camera invented by ,mr4 ,wolcott4 ,early1 however1 in #ahdj1 ,mr4 ,wolcott was desirous to be enabled to further shorten the time for a sitting1 and having some knowledge of bromine and its action1 by request1 ,dr4 ,chilton prepared a small quantity2 but ,mr4 ,wolcott did not succeed very well with it1 he having invariably used too much in combination with iodine to produce that sensitive coating now well known to the profession4 ,professor ,morse1 of this city1 ,dr4 ,goddard1 of ,philadelphia1 and others1 in the years #ahdj and #ahda1 were acquainted with the use of bromine4 ,n4 ,griffing1 of this city1 or myself1 used with tolerable success1 iodine in large excess to nitric acid and water2 and1 subsequently1 to nitro muriatic acid 7which reacted and formed a peculiar chloride of iodine72 this latter combination proved to be preferable to simple iodine1 at the same time somewhat more sensitive1 and was used by me in this city up to the time of my leaving for ,london 7,october #a1 #ahdj74 ,on arriving in ,london1 ,i instituted a series of experiments in the various chemical combinations1 solely with the view to be enabled to obtain more speedily a portrait than it was practicable to do with any known chemicals at that date4 ,the high latitude1 and the winter season of the year rendering but a feeble light at best1 the greater the necessity for a more sensitive chemical preparation to the shortening the time for a sitting4 ,near the beginning of the year #ahda1 ,i discovered and practically applied1 chloride of iodine to great advantage1 and1 as far as memory serves me1 ,i believe the first used in this country was some made and shipped1 ,messrs4 ,harnden ,co41 from ,london1 to ,mr4 ,wolcott1 in ,new ,york4 ,about the same time1 ,mr4 ,john ,goddard1 of ,london 7who was associated with myself71 discovered a rather valuable combination of chemicals1 consisting of a mixture of iodine1 bromine1 iodus1 and iodic acid1 and a proper combination of those bodies gave an action somewhat more sensitive than chloride of iodine--but the 8high lights0 of the portraits would become solarized or overdone1 more frequently with this combination than with the chloride of iodine4 ,throughout the year #ahda1 ,i used1 with great success1 chloride of iodine1 applied as one coating--occasionally in conjunction with ,mr4 ,wolcott1 attempting the use of iodine1 bromine1 and chlorine1 and at times with more or less success4 ,the difficulty of exactly combining1 the three elements above mentioned1 in order to produce a certainty of result with harmony of effect1 was the work of many months1 with great labor and study1 the slightest modification requiring a long1 series of practical experiments1 a single change consuming1 frequently1 an entire day in instituting comparisons1 etc41 etc4 ,early in the year1 #ahdb1 ,i discovered a combination of chemicals 7now known in ,london as 8,wolcott's ,mixture10 in hermetically sealed bulbs7 of exceeding uniform character1 very sensitive to the action of light1 and specimens produced in #ahdb-c1 with this combination1 will bear comparison with the best specimens produced at this late date4 ,about the same time1 ,i discovered that however much overdone a ,daguerreotype might be1 the means were at hand to save or redeem it4 ,it has long1 since been known to operators1 that if a plate be exposed to light after being coated1 unless it be again coated1 a clear and distinct picture could not be obtained upon the same plate without first repolishing and recoating the same1 care being taken that no light fall upon the prepared surface4 ,to prevent solarization1 coat a plate as usual1 expose to the action of light any required time 7according to circumstances71 say from quarter to one half more time than would be required in the ordinary method of procedure2 observe1 before putting the plate in the mercury box1 place it over the vapor of iodine1 bromine1 or chlorine1 etc4 7carefully excluding the light71 for a very brief period1 great care being required to have the selected vapor very much diluted with air1 in order to success4 ,many experiments will be required ere arriving at satisfactory results4 ,specimens now unknown to general operators1 for harmony of effect1 have been1 and may again be produced by the method pointed out above4 ,i have found the best general effect1 and the most certain result to follow from the use of the vapor of chlorine--but this requires more than ordinary care4 ,i would1 therefore1 recommend the use of iodine4 ,thus3 to a few grains of iodine1 add an ounce of warm water 7which will become tinged with iodine72 when cold1 to half a pint of pure water in a new and clean coating box1 put1 of the above1 fifty drops2 stir and mix well this small quantity of iodine in with the water2 in ten minutes this box will be ready for use4 ,great care and judgment will be required in the application of this vapor to the plate2 if the plate remain over the vapor too long1 the developed picture will have a faint and misty appearance2 if not exposed long enough1 the 8high light0 will be solarized4 ,i have great hope of the ultimate use of this process1 as it is the only means yet discovered to be enabled to secure specimens of extremes of light and shade1 yet producing harmony of effect2 and ,i would call the attention of the profession to the fact1 that a plate may be exposed to the action of light for any length of time 7a thousand times longer than required to act for the lesser quantity of mercury to deposit itself1 or that amount necessary to form a perfect specimen71 and be restored by the application of any of the vapors above mentioned1 remarking that for extremes for solarization1 denser vapors will be required4 ,much remains to be done with this discovery to the application of the ,daguerreotype4 ,,humphrey',s ,,journal ,,of ,,the ,,daguerreotype ,,photographic ,,arts4 ,the above-named publication is well known as the best and most valuable one devoted to the ,photographic ,science in this country4 ,humphrey's ,journal made its appearance ,november #ast1 #ahej1 and consequently is the first and oldest serial offered to the ,photographic world4 ,the art of producing ,portraits and ,landscapes by means of ,light1 has recently taken a new and enlivening impulse1 which will in all probability lead to important and interesting results4 ,no practical ,daguerreotypist1 ,photographer1 or amateur1 should be without the means at hand for securing all of the information upon this subject4 ,each should be ready to receive and apply the improvements as they may be developed4 ,in order to accomplish this1 it is a matter of great importance to the ,practitioner or ,experimenter that he should have a reliable medium through which he can obtain information4 ,in what source can the inquirer better place his confidence than in a regular ,journal1 whose editor is literally a practical person1 and familiar with the manipulations necessary for producing ,portraits upon 8,daguerreotype ,plates10 and upon glass and paper8 ,such is the conductor of ,humphrey's ,journal4 ,this ,journal is published once every two weeks1 and contains all the improvements relating to the ,art1 and is the only ,american ,journal whose editor is practically acquainted with the process for producing ,daguerreotypes1 ,ambrotypes1 and ,photographs4 ,the first ,no4 of ,vol4 ,x4 is dated ,may #ast1 #aheh4 ,the terms 7,two ,dollars per annum7 are trifling compared with the vast amount of information furnished4 ,,ambrotypes4--,humphrey's ,journal contains everything novel which appears upon this subject1 and has already presented more new1 important1 and original matter than can be found in any other place4 ,many are the letters we have received during the term of the last volume1 in which the writer has stated that a single number of ,humphrey's ,journal has contained information of more value to him than 8several times the amount paid for the entire volume40 ,our resources have grown up around us1 and our facilities for procuring1 as well as distributing1 all such facts and improvements as will benefit as well as instruct all who have the progress of the ,art at heart1 are as ample as they can well be made4 ,the future volumes will be abundantly furnished with original writings from persons of standing in the scientific world2 and the practical ,photographer will here find a full account of such improvements as may from time to time develop themselves4 ,from the editor's long practical experience in the ,heliographic ,science1 he will be enabled to present the subject in a plain1 clear1 and concise manner4 ,read what the ,editors say of ,humphrey's ,journal3-- 8,we have received a copy of a valuable ,journal 7,humphrey's7 published in ,new ,york1 which has reached the #ahth number of ,vol4 ,,vi4444 ,we now have the pleasure of quoting from our trans-atlantic coadjutor40--,liverpool ,photographic ,jour4 8,humphrey's ,journal is practical as well as scientific in character40--,american ,journal of ,science and ,arts4 8,it treats the subject knowingly and with force40--,new ,york ,tribune4 8,it is both a popular and interesting publication40--,mechanics' ,magazine4 8,it is highly useful to all who practice #8shadow catching4'0--,ohio ,state ,journal4 8,the work is neatly gotten up1 and contains many interesting varieties in this new field of science40--,times4 8,it should be hailed and encouraged1 not only by ,daguerreotypists themselves1 but by every lover of ,science and ,art40--,the ,democrat4 8,we cannot too strongly urge all artists1 and those persons who feel an interest in the ,heliographic ,arts and ,sciences1 to take a copy of the work40--,sentinel4 8,it is indicative of talent worthy of the important ,art it is designed to elevate40--,american4 8,this ,art is entitled to its own organ1 which could not have fallen into better hands than those of the editor of #8,humphrey's ,journal4'0--,transcript4 8,it is a scientific work of interest and usefulness40--,star of the ,north4 8,this ,journal answers many points heretofore regarded as inexplicable40--,hudson ,river ,chronicle4 8,it is rich with interest40--,north ,american4 8,it contains all the #8,improvements4'0--,delta4 8,it teaches us how to take our own portraits40--,bee4 8,it will cultivate a taste for ,daguerreotypes40--,commercial ,advertiser4 8,it should be in the hands of all40--,reveille4 8,it is the ,daguerreotypist's friend40--,london ,news4 8,it should be found in every library40--,evening ,journal4 ,from some of our ,subscribers 8,humphrey's ,journal has been the means of saving much time and money1 for by its instruction ,i have been enabled to produce some of the finest ,paper ,pictures ,i have ever seen40 ,w4 ,p4 8,don't fail to send me the ,journal1 for ,i would not be without it for five times the amount of subscription4 ,it is the only publication ,i can depend upon40 ,a4 ,g4 ,r4 8,your treatment of the humbugs and humbugging members of the profession1 is of the most valuable importance to us practical ,daguerreans4 ,go on4 ,god speed6 ,here is the amount for the renewal of my subscription40 ,e4 ,f4 ,s4 8,how can any ,operator afford to be without it80 ,l4 ,l4 ,h4 8,here are five dollars3 send me ,humphrey's ,journal to this amount4 ,i will not be without it40 ,m4 ,s4 8,it is my best friend40 ,j4 ,e4 ,w4 ,we might quote like commendatory extracts enough to more than ten times fill this page4 ,humphrey's ,journal contains #af octavo pages of reading matter4 ,,terms4 ,one copy per annum1 in advance 4 4 4 4 4 4 #b #jj ,three copies1 do4 do4 4 4 4 4 4 4 #e #jj ,six copies1 do4 do4 4 4 4 4 4 4 #i #jj ,the thousands who read it cannot be induced to remain without it4 ,all who desire to keep up with the improvements should subscribe for a copy4 ,subscription price ,two ,dollars per year4 ,don't fail to become a subscriber4 ,address ,s4 ,d4 ,,humphrey ,office1 #cg ,lispenard ,street1 ,,new ,,york4 ,,the ,,practical ,,manual ,,of ,,the ,,collodion ,,process4 ,,by ,s4 ,d4 ,,humphrey4 ,,third ,,edition ,this ,edition contains all the ,improvements in the ,art made public up to the day of publication1 and gives complete ,practical ,instructions for making ,collodion ,positives or ,ambrotypes1 ,collodion ,negatives1 ,printing1 etc41 etc4 ,the quick1 great and unprecedented sale of the first and second editions demonstrates1 more than the strongest language could possibly do1 the extraordinary and increasing popularity of this work4 ,the ,third ,edition contains two hundred and sixteen #abmo4 pages1 of a larger size and in smaller type than either of the preceding editions1 and is illustrated with numerous wood-cuts4 ,it is intended to be the best practical work extant2 substantially bound in cloth1 price ,one ,dollar2 forwarded by mail 7postage prepaid74 ,address ,s4 ,d4 ,,humphrey1 ,new ,york ,a ,,guide ,,to ,,photography1 ,containing simple and concise directions for obtaining ,views1 ,portraits1 etc41 by the chemical agency of ,light1 by ,w4 ,h4 ,thornthwaite1 author of 8,photogenic ,manipulations10 etc4 ,illustrated with numerous wood-cuts4 ,the ,book contains more than one hundred #abmo pages1 bound in board1 and is sold at twenty-five cents per copy1 or five copies for one dollar4 ,address ,s4 ,d4 ,,humphrey1 ,new ,york ,,holmes1 ,,booth ,,haydens1 ,,manufacturers ,,of ,,daguerreotype ,,cases1 ,,plates1 ,,cameras1 ,,mattings1 ,,preservers1 ,,etc41 ,,etc4 ,,manufacturers ,,and ,,importers ,,of ,,every ,,variety ,,of ,,ambrotype1 ,,and ,,photographic ,,goods1 ,of the ,best and most approved ,quality4 ,,especial ,,attention ,,given ,,to ,,the ,,furnishing ,,of ,,every ,,article ,,used ,,in ,,the ,,practice ,,of ,,the ,,daguerreotype ,depot #ha ,chambers and #fc ,reade ,st41 ,new ,york4 ,manufactory at ,waterbury1 ,conn4 ,,holmes1 ,,booth ,,haydens' ,,cameras ,from #a_/d to the ,mammoth size4 ,these ,,cameras are of the most superior make1 and all subjected to the most thorough test before being offered for sale4 ,,view ,,cameras1 made expressly for taking views3 an entirely new article4 ,,daguerreotype ,,plates1 ,,of ,,every ,,variety1 ,,and ,,we ,,would ,,call ,,particular ,,attention ,,to ,,the ,wreath1 and ,h4 ,b4 ,h4 ,eagle #dj ,plates1 ,,as ,,having ,,no ,,equals ,,in ,,the ,,market4 ,,sole ,,agents ,,for ,,the ,,celebrated ,h4 ,b4 ,,and ,n4 ,p4 ,,french ,,plates4 ,always on hand a complete assortment of ,ambrotype and ,photographic goods4 ,,sole ,,agents ,,for ,,the ,patent solid glass corner ,plate ,holders4 ,all orders will receive prompt attention1 and be forwarded with dispatch4 ,,holmes1 ,,booth ,,haydens1 #ha ,chambers1 and #fc ,reade ,st4 ,new ,york4 ,,scovill ,,manufacturing ,,co4 ,,manufacturer ,,of ,,daguerreotype ,,plates1 ,,mattings1 ,,preservers1 ,,cases1 ,,apparatus1 etc41 etc4 ,importers and ,dealers in every description of ,daguerreotype1 ,photographic1 ,,and ,,ambrotype ,,goods1 ,the ,,scovill ,,manufacturing ,,company flatter themselves that an experience of nearly twenty years in the business and the most extensive variety of the above ,goods in the ,united ,states1 entitle them to the continuance of orders for the ,domestic and ,foreign trade1 which will receive the most careful attention4 ,park ,building1 ,new ,york4 ,entrances--#cf ,park ,row1 #d ,beekman1 and #ada ,nassau ,street4 ,,scovill ,,manufacturing ,,co4 ,would call especial attention to their large variety of ,,cases1 ,embracing many ,fancy ,styles made only by themselves1 and to which they are constantly adding ,new ,designs4 ,union ,cases1 ,of all sizes1 with ,riveted ,hinges4 ,,agents ,,for ,,the ,,sale ,,of ,c4 ,c4 ,,harrison',s ,,cameras1 with improvements1 which we are now prepared to sell at reduced prices1 and warranted to give better satisfaction than ever before ,,daguerreotype ,,plates1 ,h4 ,b4--,n4 ,p4--,star and other brands ,,plate ,,glass1 embracing three-quarters white3 ,crown and all other varieties4 ,we would call particular attention to our ,black ,glass1 made expressly for ,ambrotypes4 ,,chemicals1 for the ,daguerreotype and ,photographic ,art4 ,iodized and ,plain ,,collodion4 ,gun ,cotton1 etc41 etc4 ,tagliabue's ,collodiometres and ,actino-,hydrometres1 for testing ,chemicals4 ,,apparatus ,,of ,,every ,,variety4 ,gutta ,percha1 ,porcelain1 and ,glassware of all kinds used in the ,art4 ,a large assortment of ,gilt ,frames always on hand and made to order4 ,ambrotype ,shields1 with solid corners of a new style4 ,all orders will meet with prompt attention ,,scovill ,,manufacturing ,,co41 ,,park ,,buildingm ,new ,york #cf ,park ,row1 #d ,beckman1 and #ada ,nassau ,street4 ,,hardwich',s ,,photographic ,,chemistry ,,american ,,edition4 ,a ,,manual of ,,photographic ,,chemistry1 ,,including ,,the ,,practice ,,of ,,the ,,collodion ,,process4 ,,by ,t4 ,,frederick ,,hardwich1 ,,lecturer ,,on ,,photography ,,in ,,kings ,,college1 ,,london2 ,,late ,,demonstrator ,,of ,,chemistry ,,in ,,king',s ,,college4 ,last ,edition1 ,the above is the title of this new and valuable work4 ,it is too well known to need any further comment in this place4 ,this volume contains nearly #cjj large duodecimo pages1 bound in red cloth1 #a4jj4 ,copies to be forwarded by mail1 #a4ah1 postage pre-paid4 ,s4 ,d4 ,,humphrey1 ,photographic ,book ,publisher1 #cg ,,lispenard ,,street1 ,,new ,,york1 ,n4,b4 ,postage stamps taken4