---------------------------------------- ----------------- ,transcriber's note3 ,words in bold characters are enclosed within signs4 ,the list of ,putnam ,science ,series has been moved to the advertisement section at the end of the book4 ,the ,,utf-#h version of the text file will require a ,unicode capable text reader to display a few ,greek characters and oe ligatures which occur in the book4 ---------------------------------------- ----------------- ,illustration3 ,,the ,,oldest ,,woman ,,in ,,the ,,world ,,and ,,her ,,son ,baba ,vasilka is #abf years old1 and her son ,tudor is #aja4 ,they are peasants1 and have lived all their lives in a little village in ,bulgaria4 ,they are typical examples of people who live to a great age by the use of soured milk1 as it has been their principal food all their lives4 ,the ,bacillus of ,long ,life ,a ,manual of the ,preparation and ,souring of ,milk for ,dietary ,purposes1 ,together with an ,historical ,account of the ,use of ,fermented ,milks1 from the ,earliest ,times to the ,present ,day1 and ,their ,wonderful ,effect in the ,prolonging of ,human ,existence ,by ,loudon ,m4 ,douglas1 ,f4,r4,s4,e4 ,with #fb ,illustrations ,g4 ,p4 ,putnam's ,sons ,new ,york and ,london ,the ,knickerbocker ,press #aiaa ,revised ,edition ,,copyright1 #aiaa ,,by ,g4 ,p4 ,,putnam',s ,,sons ,the ,knickerbocker ,press1 ,new ,york ,,preface ,this book has been designed with a view to meet an extensive demand for definite data on the subject of ,soured ,milks4 ,the author has had this matter brought before him1 times without number1 by those inquiring for authentic information on the subject1 and he has therefore considered it desirable to gather together such information as is available in connection with ancient and modern practice4 ,he has endeavoured to present this to the reader in concise form4 ,the author is indebted to many friends for their assistance in getting the book together1 and would specially mention ,dr4 ,h4 ,b4 ,hutchinson1 ,bacteriologist1 ,rothamsted ,experimental ,station1 for assistance in connection with the bacteriology of fermented milks2 ,mr4 ,thomas ,douglas1 of ,wimbledon1 who has assisted with the chemistry of the subject2 ,mr4 ,s4 ,javrilovitch1 of ,belgrade1 ,servia1 for local information and illustrations2 ,dr4 ,otokar ,laxa1 ,bacteriologist1 of ,prague1 ,bohemia1 for general assistance2 the editor of ,bacteriotherapy1 ,new ,york1 ,u4,s4,a41 for the use of the group of illustrations #cj-dd2 the publishers of the ,centralblatt fr ,bakteriologie1 ,jena1 for the group of illustrations #ad-bi2 and many others1 some of whom are referred to in the text4 ,,contents ,,chapter ,,page ,i4--,,introductory--,,historical #a ,,ii4--,,fermented ,,milks #ae ,,iii4--,,the ,,chemistry ,,of ,,milk #dg ,,iv4--,,handling ,,of ,,milk #fh ,v4--,,the ,,bacteriology ,,of ,,fermented ,,or ,,soured ,,milk #hd ,,vi4--,,the ,,preparation ,,of ,,soured ,,milk ,,in ,,the ,,house #abe ,,vii4--,,the ,,preparation ,,of ,,soured ,,milk ,,in ,,the ,,dairy #aci ,,viii4--,,soured ,,milk ,,in ,,health ,,and ,,disease #aea ,,index #afe ,,illustrations ,,fig4 ,,page ,,the ,,oldest ,,woman ,,in ,,the ,,world ,,and ,,her ,,son ,frontispiece ,,the ,,pass ,,of ,,bukova #b ,,kabyles ,,souring ,,milk #d ,,the ,,handling ,,of ,,milk ,,in ,,the ,,pyrenees #h ,,the ,,constituents ,,of ,,milk #dh #a4--,,micro-,,photograph ,,of ,a ,,drop ,,of ,,whole ,,milk #eh #b4--,,micro-,,photograph ,,of ,,separated ,,milk #eh #c4--,,micro-,,photograph ,,of ,,cream #eh #d4--,,photograph ,,of ,,two ,,petri ,,dishes1 ,,which ,,have ,,been ,,inoculated ,,with ,,ordinary ,,milk #fj #e4--,,the ,,creamometer #fb #f4--,,testing-,,glass ,,for ,,extraneous ,,matter ,,in ,,milk #fb #g4--,,lactometer ,,and ,,test-,,glass #fd #h4--,,pasteuriser #gh #i4--;,,continuous ,,apparatus ,,for ,,the ,,production ,,of ,,large ,,quantities ,,of ,,soured ,,milk #hb #aj4--;,a ,,milk-,,filling ,,apparatus #ij #aa4--,,section ,,through ,a ,,kephir ,,grain #id #ab4--,streptococcus lacticus 7,,grotenfeldt7 ,,growing ,,on ,,lactose-,,agar1 ,,stained ,,by ,,gram',s ,,method #if #ac4--,,photo-,,micrograph ,,of ,,preparation ,,from ,,armenian ,,soured ,,milk 7,,matzoon7 #ajf #ad4--;,,granule ,,bacillus ,,from ,,yoghourt4 ,,shredded ,,preparation ,,of ,a ,,fresh ,,skim-,,milk ,,culture #aaj #ae4--;,,granule ,,bacillus ,,from ,,yoghourt1 ,,cultivated ,,after ,,the ,,usual ,,agar ,,method #aaj #af4--;,,granule ,,bacillus ,,from ,,yoghourt4 ,,agar ,,milk ,,sugar ,,culture #aaj #ag4--;,bacteria ,w4 ,,from ,,milk1 ,,cultivated ,,twenty-,,four ,,hours #aaj #ah4--;,,agar ,,milk ,,sugar ,,culture4 ,,from ,,the ,,original ,,bulgarian ,,yoghourt #aab #ai4--;,,agar ,,milk ,,sugar ,,culture4 ,,surface ,,colony ,,of ,,granule ,,bacillus ,,from ,,calf',s ,,stomach #aab #bj4--;,,agar ,,milk ,,sugar ,,culture4 ,,deep-,,lying ,,colony ,,of ,,granule ,,bacillus ,,from ,,calf',s ,,stomach #aab #ba4--;,,agar ,,milk ,,sugar4 ,,colony ,,of ,bacterium ,w4 ,,from ,,yoghourt #aab #bb4--,,two ,,colonies ,,of ,bacillus ,acidophilus ,,from ,,calves' ,,manure #aad #bc4--;,,beer-,,wort ,,gelatine #aad #bd4--,,shredded ,,preparation ,,of ,,bulgarian ,,original ,,yoghourt #aad #be4--;,,granule ,,bacillus ,,from ,,yoghourt4 ,,cultivated ,,in ,,skim ,,milk ,,in ,,twenty-,,four ,,hours #aad #bf4--;,bacteria ,w41 ,,agar ,,milk ,,sugar ,,culture #aaf #bg4--;,bacteria acidophilus ,,from ,,calves' ,,manure #aaf #bh4--,,mucus ,,from ,,calf',s ,,stomach ,,inoculated ,,into ,,milk ,,after ,,eight ,,transferrings #aaf #bi4--;,,diplostreptococcus ,,from ,,yoghourt4 ,,pure ,,culture ,,in ,,skim ,,milk #aaf #cj4--,,photo-,,micrograph ,,of ,,preparation ,,made ,,from ,,yoghourt1 ,,showing ,,yeast ,,cells #aah #ca4--,,photo-,,micrograph ,,of ,,smear ,,from ,,greek ,,curdled ,,milk ,,called ,,giaourti #aah #cb4--,,photo-,,micrograph ,,of ,,soured ,,milk ,,inoculated ,,with ,a ,,tablet ,,containing ,,viable ,,and ,,pure ,,cultures ,,of ,bacillus bulgaricus #abj #cc4--,,photo-,,micrograph ,,of ,,milk ,,inoculated ,,with ,a ,,ferment ,,table ,,in ,,which ,bacillus bulgaricus ,,is ,,no ,,longer ,,viable #abj #cd4--,,photo-,,micrograph ,,of ,,smear ,,of ,,culture ,,of ,bacillus bulgaricus #abb #ce4--;,bacillus bulgaricus1 ,,showing ,,the ,,cultures ,,in ,,english ,,cow',s ,,milk #abd #cf4--,,photo-,,micrograph ,,of ,,pure ,,culture ,,of ,bacillus bulgaricus #abd #cg4--,,photo-,,micrograph ,,of ,,smear ,,of ,,combined ,,culture ,,of ,bacillus bulgaricus ,,and ,bacteria paralacticus #abd #ch4--,,photo-,,micrograph ,,of ,,smear ,,of ,,one-,,month ,,culture ,,of ,bacillus bulgaricus #abf #ci4--,,photo-,,micrograph ,,of ,,culture ,,of ,bacillus bulgaricus ,,in ,,malt #abf #dj4--,,photo-,,micrograph ,,of ,,smear ,,from ,,milk ,,that ,,had ,,been ,,allowed ,,to ,,sour ,,spontaneously #abf #da4--,,photograph ,,of ,,agar ,,culture1 ,,inoculated ,,with ,a ,,lactic ,,powder #abh #db4--,,photograph ,,of ,,test-,,tubes ,,of ,,sterile ,,milk1 ,,inoculated ,,with ,a ,,tablet ,,preparation ,,said ,,to ,,contain ,,pure ,,cultures #abh #dc4--,,photograph ,,of ,,test-,,tubes ,,of ,,sterile ,,milk1 ,,each ,,tube ,,having ,,been ,,inoculated ,,with ,a ,,tablet ,,of ,a ,,preparation ,,said ,,to ,,contain ,,pure ,,cultures #abh #dd4--,,photograph ,,of ,,test-,,tubes ,,of ,,sterile ,,milk ,,inoculated ,,with ,a ,,tablet ,,of ,,lactobacilline #acj #de4--;,,apparatus ,,of ,,le ,,ferment ,,co4 #abi #df4--,,soured ,,milk ,,apparatus ,,of ,,the ,,maya ,,bulgare ,,company1 ,,limited #acj #dg4--,,lactic ,,ferments1 ,,limited1 ,,apparatus #aca #dh4--,,messrs4 ,,allen ,,hanbury',s ,,soured ,,milk ,,apparatus #acb #di4--,,vironelle ,,apparatus ,,for ,,souring ,,milk1 ,,made ,,by ,,messrs4 ,,clay1 ,,paget ,,company1 ,,limited #acb #ej4--,,lactobator ,,made ,,by ,,messrs4 ,,charles ,,hearson ,,co41 ,,limited #adj #ea4--,,messrs4 ,,hearson ,,company',s ,,lactobator #adb #eb4--;,,edgar',s ,,lactogenerator1 ,,sold ,,by ,,the ,,dairy ,,supply ,,co41 ,,limited #adc #ec4--;,,apparatus ,,of ,,the ,,willows ,,refrigerating ,,co41 ,,limited #add #ed4--,,lacto ,,apparatus ,,of ,,the ,,dairy ,,outfit ,,co41 ,,limited #ade #ee4--,,sterilising ,,apparatus ,,for ,,sterilising ,,milk ,,on ,,the ,,large ,,scale #adf #ef4--;,,another ,,method ,,of ,,sterilising 7,,dairy ,,supply ,,co41 ,,ltd474 ,,an ,,american ,,apparatus ,,for ,,preparing ,,soured ,,milk #adh #eg4--;,,an ,,american ,,apparatus ,,for ,,preparing ,,soured ,,milk #adi ,,the ,,bacillus ,,of ,,long ,,life ,,chapter ,i ,,introductory--,,historical ,the milk industry is one of the oldest known to mankind1 and it is difficult to imagine a time when milk in one way or another did not form a part of the diet of the human race4 ,there is a good deal of evidence to show that in ,paleolithic and ,neolithic times1 cattle were part of the possessions of the nomadic races2 and1 according to the ,vedas1 the manufacture of butter was known in ,india #aejj years ,b4,c4 ,in the eastern part of ,europe1 milk has always been looked upon as one of the principal kinds of food1 but not necessarily the milk of cows1 as1 from ancient times to the present day1 the milk from camels1 buffaloes1 sheep1 and goats has been used indiscriminately throughout the ,east4 ,according to ,layard1#a the ,bedouins do not make cheese4 ,the milk of their sheep and goats is shaken into butter or turned into curds2 it is rarely or never drunk fresh1 new milk being thought very unwholesome1 as soon by experience ,i found it to be1 in the desert4 ,i have frequently had occasion to describe the process of making butter by shaking the milk in skins4 ,this is also an employment confined to women1 and one of a very laborious nature4 ,the curds are formed by boiling the milk1 and then putting some curds made on the previous day into it and allowing it to stand4 ,when the sheep no longer give milk1 some curds are dried1 to be used as a leaven on a future occasion4 ,this preparation1 called leben1 is thick and acid1 but very agreeable and grateful to the taste in a hot climate4 ,the sour milk1 or sheneena1 a universal beverage amongst the ,arabs1 is either buttermilk pure and diluted1 or curds mixed with water4 ,illustration3 ,,the ,,pass ,,of ,,bukova4--,during the revolution of #aijd1 a number of ,turkish soldiers1 just before traversing this pass1 were given coffee containing caf by a ,bulgarian coffee-seller1 or keeper of a small khan4 ,whilst in the pass the poison began to take effect1 and they realized that they had been poisoned4 ,fortunately for them1 a peasant with three horses loaded with ,yoghourt 7soured milk7 had taken advantage of their escort4 ,the soldiers ate freely of the ,yoghourt1 which counteracted the effects of the poison4 ,the camel's milk is drunk fresh4 ,it is pleasant to the taste1 rich1 and exceedingly nourishing4 ,it is given in large quantities to the horses4 ,the ,shammar and ,aneyza ,bedouins have no cows or oxen1 those animals being looked upon as the peculiar property of tribes who have forgotten their independence1 and degraded themselves by the cultivation of land4 ,the sheep are milked at dawn1 or even before daybreak1 and again in the evening on their return from the pastures4 ,the milk is immediately turned into leben1 or boiled to be shaken into butter4 ,amongst the ,bedouins and ,jebours it is considered derogatory to the character of a man to milk a cow or sheep1 but not to milk the camel4 ,the ,sheikhs occasionally obtain dates from the cities4 ,they are eaten dry with bread and leben1 or fried in butter1 a very favourite dish of the ,bedouin4444 ,the practice is now the same as it was in scriptural times1 when milk was looked upon as the principal article of diet1 and throughout the ,scriptures there are copious references to milk in different forms1 some of which are of peculiar interest at the present day4 ,it may be noticed1 for example1 that milk is absent from the sacred offerings amongst the ,hebrews1 and this was ascribed by the late ,professor ,robertson ,smith to the fact that all ferments were excluded from presentation at the altar1#b it being recognised that1 owing to the hot climate1 milk of all kinds became rapidly sour1 and in this way came to be looked upon as only fit for consumption when in that condition4 ,it has been suggested that the prohibition referred to is on the same level as the prohibition of the use of blood1 as milk has sometimes been regarded as a kind of equivalent for blood1 and containing the sacred life4#c ,to this day the wandering tribes of ,arabia consider the milk of their camels and flocks more refreshing when it has been slightly fermented or soured by being poured into a milk-skin on the inside of which are still sticking sour clots from the previous milking1 and there shaken for a brief period2 but this slightly soured milk 7the ,oxygala of ,pliny7 is known widely in the ,east simply as leben 7milk74 ,the name is also applied to what we term buttermilk4#d ,illustration3 ,,kabyles ,,souring ,,milk ,in the north of ,africa the use of soured milk is common1 and the illustration shows ,kabyles shaking a skin full of milk so as to sour it4 ,the skin has previously been used for the same operation1 and1 as a consequence1 clots of milk are left from the previous day's use1 and thus fermentation is set up4 ,the use of milk-skins for the carrying of milk is not confined to one country1 as1 while it is common all over the north of ,africa1 it is also known in the ,pyrenees and in some parts of the ,balkan ,peninsula1 the object being identical in each case2 and when it is intended to make butter from the milk1 the skin is simply rocked between the knees until the butter separates1 a process of butter-making which was also used after the introduction of earthenware churns4#e ,dried soured milk is also used by the ,arabs1 and it is reconstituted when required by rubbing it up with a little water1 and it is known as ,meeresy4#f ,the ordinary soured milk is the common article of diet1 and is looked upon as being necessary at every meal1 and travellers frequently refer to the use of this product1 as a few references will show4 ,charles ,g4 ,addison states3 ,a supper was brought in on a round tray4 ,in the centre was a huge pilaff of rice1 and around it several small dishes of stewed meats1 grilled bones1 sour clotted milk called yaoort1#g bits of meat roasted1 etc4444 ,we retired into a tent to breakfast1 where we found an immense bowl of delicious fresh camels' milk1 with thin hot cakes of unleavened bread1 baked upon the ashes1 ready prepared for us4 ,the principal food of the ,bedouins consists of flour and some camels' milk made into a paste1 boiled1 and eaten swimming in melted grease and butter2 boiled wheat and beans dried in the sun and prepared with butter are a favourite dish4 ,they are all remarkably fond of butter and grease2 the butter is made in a goat-skin1 suspended to the tent pole1 and constantly shaken about by the women4#h ,burckhardt#i says3 ,the provisions of my companion consisted only of flour2 besides flour1 ,i carried some butter and dried leben 7sour milk71 which would dissolve in water4 ,it forms not only a refreshing beverage1 but is much to be recommended as a preservative of health when travelling in summer4 ,these are our only provisions4 ,with regard to the inhabitants of the ,houran1 ,burckhardt relates that the most common dishes of these people are bourgoul and keshk4 ,in summer they supply the place of the latter by milk1 leben1 and fresh butter4 ,of the bourgoul ,i have spoken on other occasions2 there are two kinds of keshk--keshk-hammer and keshk-leben4 ,the first is prepared by putting leaven into the bourgoul and pouring water over it4 ,it is then left until almost putrid1 and afterwards spread out in the sun and dried1 after which it is pounded1 and1 when called for1 served up mixed with oil or butter4 ,the keshk-leben is prepared by putting leben into the bourgoul instead of leaven2 in other respects the process is the same4 ,keshk and bread are the common breakfasts4 ,towards sunset a plate of bourgoul1 or some ,arab dish1 forms the dinner4 ,again1 ,taylor#aj says3 ,i received a small jug of thick buttermilk1 not remarkably clean1 but very refreshing4 ,these references particularly refer to the ,east1 from which it would appear that soured milk was universally known in ancient times as it is at the present day1 and this remark applies not only to ,egypt1 ,palestine1 and ,arabia1 but throughout ,turkey and the ,balkan ,states1 where the consumption of soured milk is equally common4 ,it seems curious that the use of this commodity should have been confined for centuries to the ,east1 as we shall see later on that its dietetic value is so great that it is really a wonderful thing that no one has taken the trouble to introduce its use to the ,western nations until quite recently4 ,illustration3 ,,the ,,handling ,,of ,,milk ,,in ,,the ,,pyrenees ,the handling of milk in the ,pyrenees is1 more especially in the villages1 conducted in goat or sheep skins1 in a similar way to the methods which prevail in ,eastern ,europe1 and the picture shows a skin of milk on a small farm in the ,pyrenees4 ,the churning is very often performed by simply rocking the skin between the knees1 acidity being induced by remnants of the previous day's milk2 souring of milk is induced by the same method4 ,a curious example of how the virtues of such an article may be independently discovered by another nation is to be found in ,lapland1 where reindeer's milk is the article used4 ,the reindeer's milk1 says ,acerbi1#aa constitutes a principal part of the ,laplander's food1 and he has two methods of preparing it1 according to the season4 ,in summer he boils the milk with sorrel till it arrives to a consistence2 in this manner he preserves it for use during that short season4 ,in winter the following is his method of preparation3 ,the milk1 which he collects in autumn till the beginning of ,november1 from the reindeer1 is put into casks1 or whatever vessels he has1 in which it soon turns sour1 and1 as the cold weather comes on1 freezes1 and in this state it is kept4 ,the milk collected after this time is mixed with cranberries and put into the paunch of the reindeer1 well cleaned from filth2 thus the milk soon congeals1 and it is cut out in slices1 together with the paunch1 to effect which a hatchet is used1 for no smaller instrument would perform the office of dividing that lump of ice4 ,it is then separated into small pieces and eaten throughout the winter every day at noon1 which is the ,laplander's dinner-hour4 ,it must be presumed1 as it is served up without being brought to the fire1 that this is ice-cream in the greatest perfection3 here are flesh and fruit blended with the richest butyraceous milk that can be drawn from any animal2 but1 notwithstanding the extraordinary fatness1 which may be supposed to resist in a great degree the effect of cold1 this preparation1 as our good missionary remarks with a degree of feeling1 as if his teeth still chattered whilst he delivered the account1 chills and freezes the mouth in a violent manner whenever it is taken4 ,the milk which is drawn late in the winter freezes immediately after being drawn4 ,this is put into small vessels made of birchwood1 and is considered by the ,laplander as such an extraordinary delicacy1 that he reserves it as the most acceptable present he can offer even a missionary4 ,it is placed before the fire and eaten with a spoon as it is thawed4 ,when put by1 it is carefully covered up1 because if the cold air gets to it afterwards1 it turns of a yellow colour and becomes rancid4 ,amongst the peasants at the present day1 soured milk is known as yoghourt1 a word which is spelt differently according to the locality in which it is used4 ,the method of preparation is practically the same everywhere1 and a short description of the process as now carried out in one place would1 with slight modifications1 apply to the general method adopted all over the ,east4 ,the culture1 says a correspondent at ,varna1 which is used for the preparation of yogourt1 is known as ',maya' or as ',bulgarian ,maya4' ,the milk which is to be converted into yogourt must first be freed from all bacteria by boiling and allowed to cool to the temperature of #de ,c42 it is then inoculated with maya and maintained at an even temperature of #de ,c4 during several hours4 ,there are two kinds of maya1 or ferment1 one known as sour1 and the other as sweet maya4 ,in ,europe small stoves1 made expressly for the purpose1 are used to maintain the milk at the proper temperature4 ,in this country1 however1 after the milk has been boiled1 it is merely poured into a bowl and allowed to cool to approximately #de ,c41 then a tablespoonful of this tepid milk is well mixed 7in a small bowl apart7 with a similar quantity of maya1 and the mixture1 when it has become quite homogeneous1 is added to the bowl of tepid milk and stirred slightly4 7,one tablespoonful of maya is sufficient to ferment one litre of milk47 ,a cover is then placed on the bowl and the whole is enveloped in flannel and left in a warm place for three hours in summer1 and somewhat longer in winter4 ,the process of preparation is complete when the mixture assumes the appearance of a soft mass somewhat resembling cream cheese1 but less solid4 ,the flannel is then removed1 the bowl uncovered and placed in a cool spot until needed for consumption4 ,of the yogourt thus prepared1 a tablespoonful is kept to serve as maya for the following day4 ,the best yogourt is prepared from sheep's milk1 the second quality from buffaloes' milk1 and the third quality from cows' milk4 ,yogourt forms an almost daily article of diet with the natives in this country4#ab ,with regard to the time stated for the fermenting process1 it must be noted that since the subject has been investigated so thoroughly1 the time required for fermentation has been found to be nearer ten than three hours1 but this will be dealt with in a subsequent chapter4 ,historically it may be gleaned from the fragmentary references which we have given1 that soured milk has1 from time immemorial1 formed the principal article of diet of a great many peoples1 and the notable feature in connection with it is1 that in some countries where it is in daily use1 the age limit for human beings seems to be very much extended1 and it would appear that there is a direct connection between the use of soured milk and longevity4 ,in ,bulgaria1 for example1 it is stated that the majority of the natives live to an age considerably in excess of what is recognised as the term of life amongst ,western nations1 and inquiry has shown that in the eastern part of ,southern ,europe1 amongst a population of about three millions1 there were more than three thousand centenarians found performing duties which would not be assigned to a man of sixty-five years of age elsewhere4 ,it is quite common to find amongst the peasants who live to such a large extent upon soured milk1 individuals of #aaj and #abj years of age4#ac ,in the ancient dairy practice1 as we have seen1 soured milk was the principal product1 and the extraordinary ages which are recorded of the patriarchs1 if translated into the modern denomination1 would not appear to be so imaginary after all1 when it is considered that we have thousands of examples at the present day of men and women enjoying quite as long a term of existence4 ,it has been noticed also1 that while these very old people are able to perform a certain amount of manual labour1 there is not the same tendency to the mental decay which is so prominent and sad a feature amongst ,western nations1 at a period of about seventy or eighty years of age4 ,it would seem1 indeed1 as if the habit of living long was well known in ancient times1 and that1 like many other of the valuable arts and sciences1 it fell under a cloud during the ,middle ,ages1 or1 perhaps1 the significance of the use of soured milk fell into neglect1 and1 even after the revival of letters in the sixteenth century1 still remained obscure4 ,the discovery of micro-organisms in perishable products1 which is attributable to ,anthony ,van ,leeuwenhoek1 a ,dutchman1 whose vocation was the polishing of lenses1 and who lived between #afcb and #agbc1 altered our point of view1 not only of disease1 but of all the functions carried on by the lower organisms4 ,since ,van ,leeuwenhoek's time1 the germ theory has grown to vast proportions and has more especially been applied with splendid results to the study of milk4 ,as we shall see later1 the researches of modern investigators have led them to the conclusion that micro-organisms play such an important part in the milk supply1 that it is impossible to carry it on safely without a knowledge of the bacteriology of the subject4 ,this view began to prevail about #ahij1 some twenty years after ,pasteur had shown what fermentation really meant4 ,since that time1 the progress in dairying has been continuous1 and1 during recent years1 attention has been directed to soured milk to such an extent that it has become necessary for all who are interested in the handling of milk and milk products to have a knowledge of the subject1 as it seems clearly demonstrated that1 under proper direction1 there is every possibility of its forming an important element in the prolongation of life4 ,,chapter ,,ii ,,fermented ,,milks ,there is considerable variety in the number of soured or fermented milks1 and they are known by various names1 such as ,koumiss or ,koomiss1 which is prepared from mares' milk2 ,keffir1 which was originally discovered in the mountains of the ,caucasus1 and which is prepared with ,keffir grains2 ,leben1 an ,egyptian product prepared from the milk of the buffalo1 cow1 or goat2 ,matzoon1 a soured milk which is prepared in ,armenia from ordinary cows' milk2 ,dadhi1 an ,indian preparation from cows' milk4 ,all of these owe their special characteristics to the fact of their having undergone lactic and alcoholic fermentation4 ,milk left to itself1 says ,blyth1#ad at all temperatures above #ij ,f4 begins to evolve carbon dioxide1 and this is simply a sign and result of fermentation4 ,if this fermentation is arrested or prevented1 the fluid remains perfectly sweet and good for an indefinite time4 ,besides the production of carbon dioxide during decomposition1 a certain portion of milk sugar is converted into lactic acid1 some of the casein and albumen are broken up into simpler constituents1 and a small proportion of alcohol produced1 which by oxidation appears as acetic acid1 while the fat is in part separated into free fatty acids1 which ultimately unite with the ammonia produced by the breaking up of the albuminoids4 ,the main fermentation of milk is a special kind which of late years has been much studied1 and is known as lactic fermentation4 ,accompanying lactic fermentation there is nearly always a weak butyric and a weak alcoholic fermentation4 ,one of the organisms causing ,butyric ,acid ,fermentation is a bacillus #c to #aj in length1 and about #a in breadth4 ,it has power of movement1 and when cultivated in gelatine1 liquefies the gelatine1 forming a scum on the surface4 ,when the bacillus is sown into sterile milk1 the following1 according to ,hueppe1 are the changes3 ,if the milk thus infected is incubated1 on the second day a clear1 slightly yellow fluid is seen under the layer of cream2 this fluid increases from day to day1 so that gradually a column of fluid is formed which is quite clear above1 but below is turbid2 the casein1 at first thrown down in a firm coagulum1 in the course of eight days begins to be attacked1 and by the end of two or three weeks most of it is dissolved4 ,the filtered fluid gives the biuret reaction2 it contains leucin1 tyrosin1 and ammonia2 hence it is clear that the ferment acts to some extent as a digestive of albumen4 ,in advanced butyric acid fermentation1 the fluid is most offensive1 and may have an alkaline reaction4 ,lactic acid was first isolated by ,scheele in #aghj from soured milk1 but its exact constitution was not determined until later by ,liebig1 ,mitscherlich1 ,gay-,lussac1 and ,pelouze3 ,it is widely distributed in nature1 occurring in the sap of the vine and in most fermented liquids1 especially in soured milk2 it is not1 however1 present in fresh milk4#ae ,in all the ,eastern preparations referred to1 the lactic fermentation is produced1 followed by alcoholic fermentation1 which is due to the slow decomposition of the milk sugar1 the vinous fermentation being most readily set up in milks which contain a larger relative proportion of milk sugar and water1 such as the milk derived from the mare1 the sheep1 and the camel4 ,as these fermented milks have different characteristics1 it is necessary to the thorough understanding of the process of manufacture at the present day1 to examine them in some detail4 ,koumiss4--,the greatest of all the fermented milks is koumiss1 and it has been celebrated from the most ancient times until the present day1 as being the principal food of the wandering tribes of ,khirgiz1 ,bashkirs1 ,kalmucks1 and ,tartars1 who inhabit the steppes of ,european ,russia and the plains of ,south1 ,western1 and ,central ,asia4 ,according to ,carrick1 who has written an interesting volume on the subject1#af the nomads who inhabit these vast territories are shut up under the most miserable circumstances during the winter time and at the advent of spring they roam over the steppes from morning to night1 usually in the saddle4 ,the milk yielded at such time by the mares is carefully collected1 and these nomads consume enormous quantities of it in the fermented state1 this habit having been in existence amongst them from time immemorial4 ,it is said that the ,scythians1 long before the ,christian era1 used fermented mares' milk2 and there are ornaments in existence in ,russia1 of ,scythian origin1 which exhibit in detail the preparation of koumiss from mares' milk4 ,in historical times1 the first mention of koumiss was in the twelfth century1 when it is referred to in the ,ipatof ,chronicles4 ,during the thirteenth century ,william de ,rubruquis1 a ,french missionary1 wrote about his travels in ,tartary1 and he described how he had first become acquainted with koumiss1 and how he found it savoury to the palate4 ,subsequent to this1 however1 there is very little mention of koumiss in ,russian history1 or1 for that matter1 in any other1 and the first really scientific contribution on the subject was by ,dr4 ,john ,grieve1 who was a surgeon in the ,russian army1 and who in the year #aghd sent a description of koumiss to the ,royal ,society of ,edinburgh1#ag of which he was a member1 and the title of it was1 ,an ,account of the ,method of ,making ,wine called by the ,tartars ,koumiss1 with ,observations on its ,use as a ,medicine4 ,dr4 ,grieve strongly advocated the use of koumiss as beneficial in cases of wasting diseases1 and subsequently it was adopted by the medical profession1 with the result that sanatoria for the treatment of pulmonary consumption were established at ,samara and other places in ,russia1 and met with very great success2 and at the present day such sanatoria are carried on1 but the bacteriology of the subject now being thoroughly understood1 the methods of preparation have been somewhat modified4 ,an interesting account of koumiss is given by ,clarke1#ah who says3 ,everybody has heard of koumiss1 and the brandy which the ,kalmucks are said to distil from the milk of mares4 ,the manner of preparing these liquids has been differently related1 and perhaps is not always the same4 ,they assured us that the brandy was merely distilled from buttermilk4 ,the milk which they collect overnight is churned in the morning into butter2 and the buttermilk is distilled over a fire made with the dung of their cattle1 particularly the dromedary1 which makes a steady and clear fire like peat4 ,but other accounts have been given both of the koumiss and the brandy4 ,it has been usual to confound them1 and to consider the koumiss as their appellation for the brandy so obtained4 ,by other information ,i could gain1 not only here1 but in many other camps which we afterwards visited1 they are different modifications of the same thing although different liquors2 the koumiss being a kind of sour milk1 like that so much used by the ,laplanders called pina1 and which has undergone1 in a certain degree1 the vinous fermentation2 and the brandy an ardent spirit obtained from koumiss by distillation4 ,in making koumiss they sometimes employ the milk of cows1 but never if mares' milk can be had1 as the koumiss from the latter yields three times as much brandy as that made from cows' milk4 ,the manner of preparing the koumiss is1 by combining one sixth part of warm water with any given quantity of warm mares' milk4 ,to these they add1 as a leaven1 a little old koumiss1 and agitate the mass till fermentation ensues4 ,to produce the vinous fermentation1 artificial heat and more agitation is sometimes necessary4 ,this affords what is called koumiss4 ,the subsequent process of distillation afterwards obtains an ardent spirit from the koumiss4 ,they call it vina4 ,in their own language it bears the very remarkable appellation of rack and racky1 doubtless nearly allied to the names of our ,east ,india spirit rack and arrack4 ,we brought away a quart bottle of it1 and considered it very weak bad brandy1 not unlike the common spirit distilled by the ,swedes and other northern nations4 ,some of their women were busy making it in an adjoining tent4 ,the simplicity of the operation and their machinery was very characteristic of the antiquity of this chemical process4 ,their still was constructed of mud1 or very coarse clay2 and for the neck of the retort they employed a cane4 ,the receiver of the still was entirely covered by a coating of wet clay4 ,the brandy had already passed over4 ,the woman who had the management of the distillery1 wishing to give us a taste of the spirit1 thrust a stick1 with a small tuft of camel's hair at its end1 through the external covering of clay1 and thus collecting a small quantity of the brandy1 she drew out the stick1 dropped a portion on the retort1 and1 waving the instrument above her head1 scattered the remaining liquor in the air4 ,i asked the meaning of this ceremony1 and was answered that it is a religious custom to give always the first drop of the brandy which they draw from the receiver to their ,god4 ,the stick having been plunged into the receiver again1 she squeezed it into the palm of her dirty and greasy hand1 and after tasting the liquor1 presented it to our lips4 ,another interesting account of the preparation of koumiss is given by ,john ,m4 ,wilson in the ,rural ,encyclopdia1#ai and it shows that the methods in use about the middle of last century did not differ materially from those which existed centuries before4 ,wilson says3 ,khoumese is vinously fermented mares' milk4 ,any quantity of fresh mares' milk is put into wooden vessels2 a sixth part of water just off the boil is mixed with it2 an eighth part of old khoumese or of the sourest possible cows' milk is added2 the mixture is kept from fifteen to twenty-four hours1 covered up with several folds of coarse linen cloth and with a very thick board1 and without being stirred or in any degree disturbed1 in a moderately warm place till it becomes thoroughly sour1 and sends up a thick mass to its surface2 it is then beaten and pounded and stirred till the curd is not only broken1 but so thoroughly mixed with the serum as to form a thick liquid2 it next remains covered and at rest during twenty-four hours more1 and it is finally put into a common butter churn and beaten and blended into a state of perfect homogeneity4 ,it is now fit for use2 yet it acquires an increase of given properties if it be allowed to stand for a few days1 and either then or now it would1 if distilled1 yield nearly one third of its own bulk of a weak spirit which will bear to be rectified4 ,whenever it is used it must be previously so agitated that its component parts may be well mixed together1 and it may be kept either in pans for immediate use or in casks for more remote use2 and if placed in a cool cellar it will remain good during three or four months4 ,mares' milk owes its peculiar fitness for making koumiss to its containing a large proportion of sugar of milk1 and readily undergoing the vinous fermentation1 and it possesses a general medicinal reputation among the ,tartars similar to that which asses' milk has partially acquired in ,britain4 ,that mares' milk will undergo vinous fermentation and yield a certain quantity of spirit1 says a writer in the ,magazine of ,domestic ,economy1 is not generally known1 and it was reserved for a nation of demi-savages to render this circumstance available as an agent of health1 as well as an agreeable and nourishing beverage4 ,every educated person1 however1 has heard that the ,tartars drink mares' milk1 though few know that this milk is taken on account of its specific virtues alone1 and not as a substitute for cows' milk1 of which they have abundance1 and with which they adulterate mares' milk when scarce4 ,but the koumiss is reputed to be much more medicinal than the mares' milk itself2 and on account of its being free from all tendency to curdle in the stomach1 and of its possessing most of the nutritive power of the milk in combination with native fermented spirit1 it has been strongly recommended by some persons as a remedy for most or all cases of general debility1 of nervous languor1 and even pulmonary disease4 ,khoumese is called sometimes koumiss and sometimes milk wine4 ,from these references it will be seen that koumiss is an alcoholic drink made by the fermentation of mares' milk1 but it is also frequently prepared from the milk of the camel and cows' milk4 ,it is stated that a similar preparation to ,russian koumiss is made in ,switzerland from cows' milk simply by the addition of a little sugar and yeast to skim milk2 it contains more sugar and less lactic acid than ,russian koumiss1 and on account of the much greater proportion of casein contained in cows' milk1 differs considerably from that prepared from mares' milk4 ,suter-,naef gives the composition of a ,swiss koumiss#bj manufactured at ,davos as follows3 ,in ,grams4 ,per ,litre ,per cent4 7by weight74 ,water #ij4cdf #ajai4fd grams4 ,alcohol #c4baj #cf4bc ,lactic acid #j4aij #b4ad ,sugar #b4aje #bc4ge ,albuminates #a4hfj #bj4ii ,butter #a4ghj #bj4ji ,inorganic salts #j4eji #e4gd ,free carbonic acid #j4agg #b4jj ,the ferments used in the preparation of koumiss are stated by ,carrick to be of two different kinds1 artificial and natural4 ,of the natural ferments two have been resorted to4 ,one is mentioned by ,grieve1 which he borrowed from the ,bashkirs of ,orenbourg1 and which simply consists in the addition of one sixth part of water and one eighth of the sourest cows' milk to fresh mares' milk2 the other has been employed1 and was1 if ,i mistake not1 first recommended by ,bogoyavlensky4 ,it is a very simple if rather a tedious method4 ,new mares' milk1 diluted with one third its bulk of water1 is placed in the saba1#ba and while allowed to sour spontaneously1 is continually beaten up4 ,this milk gradually undergoes the vinous fermentation1 and in twenty-four hours is converted into weak koumiss4 ,the disadvantage of this mode of commencing fermentation is obvious--viz41 the great waste of time in agitation4 ,hence it is only employed when no artificial ferment is obtainable4 ,in starting the process of fermentation in mares' or any other kind of milk1 therefore1 an artificial ferment is more frequently employed than a natural one4 ,the former is used only for converting the first portion of milk into koumiss2 the latter is always resorted to afterwards4 ,of artificial ferments the variety is great1 for besides all putrefying animal matters which contain nitrogen--such as blood1 white of egg1 glue1 and flesh--certain mineral substances which act by souring the milk are also capable of exciting fermentation4 ,now1 many of the nomads1 whose mares either give no milk or are not milked in winter1 commence the preparation of their koumiss in spring by borrowing a ferment from the animal1 mineral1 or vegetable kingdom4 ,thus a mixture of honey and flour is the favourite ferment with some races of nomads2 a piece of fresh horse-skin or tendon is preferred by others1 while a few resort to old copper coins1 covered with verdigris1 for starting fermentation4 ,in the choice of a ferment they are guided solely by habit and tradition4 ,as it would be useless1 almost impossible1 to give a list of all the foreign substances that have been employed with the view of converting mares' milk into koumiss1 it will be best to consider the simplest artificial ferments1 and those most generally in use4 ,the simplest way is that recommended by ,bogoyavlensky1 and adopted and modified by ,tchembulatof4#bb ,it is prepared thus3 ',take a quarter of a pound of millet-flour1 add water to it1 and boil it down to the consistence of thick oatmeal porridge4 ,then heat separately1 in another vessel1 eleven pints of milk to boiling-point1 and allow it to cool down4 ,when its temperature has fallen to #ie ,f41 pour it into a wooden bowl or tub1 and add the boiled flour to it4 ,the upper and open part of the vessel is then covered with a piece of coarse linen1 and left at rest--at a temperature of about #ii ,f4--from twenty-four to forty-eight hours4 ,the appearance of small bubbles1 which keep bursting on the surface of this liquid1 combined with a vinous or acid odour1 prove that the ferment is ready4 ,to this fermenting fluid twenty-two quarts of new milk are gradually 7i4e41 every ten minutes7 added1 and the whole mass is continuously beaten up for twelve hours4 ,the temperature during stirring should never be higher than #id ,f4 ,the whole fluid soon begins to ferment1 and after twelve hours a not unpleasant koumiss is ready4 ,this should be filtered through a horse-hair or muslin sieve1 after which it is fit for drinking4 ,this liquid is called weak koumiss2 but a limited portion of the lactine has undergone the lactuous and vinous fermentations1 and thus the percentage of alcohol is small4 ,koumiss at an ordinary temperature remains weak for twelve hours after it has been beaten up1 and then gradually passes into medium4' ,curiously enough1 the richness of cows' milk in fat militates against its being a good raw material for the making of koumiss1 owing to the production of small quantities of butyric acid1 which follows upon the fermentation1 so that it is desirable1 if koumiss is to be prepared from cows' milk1 that the fat should be first of all eliminated1 so that the separated milk will then approximate to the composition of mares' milk4 ,the chemical changes1 says ,hutchison1#bc which take place in the milk under the double fermentation are not difficult to follow2 the lactic ferment simply changes part of the sugar into lactic acid1 the vinous ferment eats up a very small part of the proteid of the milk1 and1 at the same time1 produces from the sugar a little alcohol and a good deal of carbon dioxide2 the milk thus becomes sour1 it effervesces and is weakly alcoholic1 but the lactic acid causes the casein to be precipitated just as it does in the ordinary souring of milk1 and the casein falls down in flocculi4 ,as will have been noticed1 it is an essential part of the process of koumiss-making to keep the milk in a state of agitation during the period of fermentation1 a process which is intended to permit of oxygen being taken up by the fermenting fluid1 while1 at the same time1 the casein is broken up into a state of fine division4 ,the casein also1 or at least a portion of it1 becomes very soluble1 and after twelve hours of fermentation the taste of the product is only slightly sour1 and the milk taste still remains4 ,this taste1 however1 disappears in twenty-four hours1 owing to the rapid development of the lactic acid organisms4 ,after this lapse of time the sugar is entirely destroyed1 and the strong koumiss which results is a thin sour fluid which effervesces briskly1 and in this condition will keep for an indefinite period4 ,the net change which has taken place in the original milk may be summed up by saying that the sugar of the milk has been replaced by lactic acid1 alcohol1 and carbon dioxide1 the casein has been partly precipitated in a state of very fine division1 and partly pre-digested and dissolved1 while the fat and salts have been left much as they were4#bd ,violent stirring or agitation of the cultures does not seem to work so much by supplying oxygen to the fermenting liquid1 as by ensuring a thorough distribution of the micro-organisms throughout the liquid1 and thus dividing the casein4 ,the greater number of the organisms are facultative anrobes and oxygen is not necessary4 ,again1 koumiss put up in bottles on the first day is regularly shaken although air is excluded4 ,keffir4--,keffir is a kind of fermented milk which has been in use in the ,caucasus for quite a long time1 as koumiss has been in the steppes4 ,it differs from koumiss1 however1 in this respect1 that it is prepared from either sheep's1 goats'1 or cows' milk4 ,the process is started by the addition of keffir grains to the milk1 which is contained in leathern bottles4 ,these keffir grains are small solid kernels which are kept in families and handed on from one generation to another4#be ,the grains are the origin of the ferment1 as they disseminate in the milk micro-organisms of a lactic yeast 7,saccharomyces kefir ,beyerinck and ,freudenreich7 and also the bacillus ,bacterium caucasicum1 which develop rapidly and split up the milk sugar into carbon dioxide1 alcohol1 and lactic acid4 ,small quantities of glycerine1 acetic1 succinic1 and butyric acids are also formed1 the casein and albumen being partly peptonised4#bf ,keffir becomes slightly effervescent in twenty-four hours1 and in that time develops a small quantity of alcohol1 but after three days the amount of alcohol and lactic acid is much increased4#bg ,it has been determined that the fermentation of the milk is due to ,saccharomyces kefir1 and that the ,lactobacillus ,caucasicus does not take any part in the fermentation1 a fact which seems to be supported by the capacity of ordinary keffir for starting the fermentation in fresh milk in the same manner as the keffir grains4 ,the use of this beverage seems to be universal throughout the ,caucasus1 and travellers in these regions have frequently referred to it4 ,thus ,freshfield#bh states in one part of his book of travels as follows3 ,the pig-faced peasant against whom we had at first sight conceived such an unjust prejudice turned out a capital fellow4 ,he brought us not only fresh milk1 but a peculiar species of liquor1 something between public-house beer and sour cider1 for which we expressed the greatest admiration1 taking care at the same time privately to empty out the vessel containing it1 on the first opportunity4 ,and again3 ,the hospitable shepherds regaled us1 not only with the inevitable and universal airam or sour milk--if a man cannot reconcile himself to sour milk1 he is not fit for the ,caucasus--but with a local delicacy that has lately been brought to the knowledge of ,europe--kefir4 ,this may best be described as 'effervescing milk4' ,it is obtained by putting into the liquid some yellow grains1 parts of a mushroom which contains a bacillus known to science as ,dispora caucasia4 ,the action of the grains is to decompose the sugar in the milk1 and to produce carbonic acid and alcohol4 ,the grains multiply indefinitely in the milk2 when dried they can be preserved and kept for future use2 its results on the digestion are frequently unsatisfactory1 as one of my companions learnt to his cost4 ,it has been supposed1 says ,metchnikoff1 that the chief merit of kephir was that it was more easy to digest than milk1 as some of its casein is dissolved in the process of fermentation4 ,kephir1 in fact1 was supposed to be partly digested milk4 ,this view has not been confirmed4 ,professor ,hayem thinks that the good effects of kephir are due to the presence of alcoholic acid1 which replaces the acid of the stomach and has an antiseptic effect4 ,the experiments of ,m4 ,rovigh1 which ,i speak of in ,the ,nature of ,man1 have confirmed the latter fact1 which now may be taken as certain4 ,the action of kephir in preventing intestinal putrefaction depends on the lactic acid bacillus which it contains4 ,kephir1 although in some cases certainly beneficial1 cannot be recommended for the prolonged use necessary1 if intestinal putrefaction is to be overcome4444 ,professor ,hayem prohibits its use in the case of persons in whom food is retained for long in the stomach4 ,when it is retained in the stomach1 kephir goes on fermenting1 and there are developed in the contents butyric and acetic acids1 which aggravate the digestive disturbances4 ,kephir is produced by combined lactic and alcoholic fermentations 444 and it is the lactic and not the alcoholic fermentation on which the valuable properties of kephir depend2 it is correct to replace it by sour milk1 that contains either no alcohol or merely the smallest traces of it4 ,the fact that so many races make sour milk and use it copiously is an excellent testimony of its usefulness4 ,there are two methods given by ,flgge#bi for the preparation of keffir3 ,in the first1 the dry brown kefir grains of commerce are allowed to lie in water for five or six hours until they swell2 they are then carefully washed and placed in fresh milk1 which should be changed once or twice a day until the grains become pure white in colour and when placed in fresh milk1 quickly mount to the surface--twenty to thirty minutes4 ,one litre of milk is then poured into a flask1 and a full tablespoonful of the prepared krner added to it4 ,this is allowed to stand open for five to eight hours2 the flask is then closed and kept at #ah ,c4 ,it should be shaken every two hours4 ,at the end of twenty-four hours the milk is poured through a fine sieve into another flask1 which must not be more than four fifths full4 ,this is corked and allowed to stand1 being shaken from time to time4 ,at the end of twenty-four hours a drink is obtained which contains but little carbon-dioxide or alcohol4 ,usually it is not drunk until the second day1 when1 upon standing1 two layers are formed1 the lower milky1 translucent2 and the upper containing fine flakes of casein4 ,when shaken it has a cream-like consistence4 ,on the third day it again becomes thin and very acid4 ,the second method is used when one has a good kefir and two or three days to start with4 ,three or four parts of fresh cows' milk are added to one part of this and poured into flasks which are allowed to stand for forty-eight hours with occasional shaking4 ,when the drink is ready for use1 a portion 7one fifth to one third7 is left in the flask as ferment for a fresh quantity of milk4 ,the temperature should be maintained at about #ah ,c41 but at the commencement a higher temperature is desirable4 ,the grains should be carefully cleaned from time to time and broken up to the size of peas4 ,the clean grains may be dried upon blotting-paper1 in the sun1 or in the vicinity of a stove2 when dried in the air they retain their power to germinate for a long time4 ,leben4--,in our earlier references to fermented milks in scriptural times1 we observed that alcoholic fermented milks were not permitted to be presented at the altar4 ,such offerings1 however1 were quite allowable amongst the ancient ,egyptians1 the ,arabs and ,carthaginians1#cj and from remote antiquity these nations placed great value on this product4 ,leben1 which is peculiarly associated with ,egypt1 is a soured milk prepared from the milk of buffaloes1 cows1 or goats4 ,it is usually prepared by the boiling of the fresh milk over a slow fire1 after which some fermented milk from a previous preparation is added to the warm article1 and the fermentation takes place rapidly and is considered to be complete in about six hours4#ca ,the ,egyptian leben is valued so highly that it is offered in hospitality to the passing stranger1 and it is regarded as so much of a duty to present this milk1 that in some parts of ,arabia it would be looked upon as scandalous if any payment were received in return4#cb ,matzoon4--,matzoon is prepared in ,armenia in somewhat the same manner as keffir is prepared in the ,caucasus1 and indeed it differs very slightly from keffir in composition4 ,its use is universal in ,armenia4 ,dadhi4--,in ,india large quantities of fermented milk are used1 under the name of ,dadhi1 and its characteristics are not unlike the similar products in ,europe4 ,the specific bacillus has been investigated by ,chatterjee1#cc who concludes that it is somewhat akin to the ,bacillus bulgaricus and the bacillus of leben 7,b4 lebenis74 ,dr4 ,chatterjee gives a rsum of his investigations which sums up the whole matter thus3 #a4 ,the fermented milk of ,india called ,dadhi resembles in all essential points the ,bulgarian fermented milk as well as the leben and other forms of fermented milk in use in the ,east4 #b4 ,the causative element of the curdling process of ,dadhi is a streptothrix having characters similar to the ,bacillus bulgaricus and ,streptobacilli lebeni1 and ,bacillus caucasina and the ,long ,bacilli of ,mazun1 in 7#a7 not growing in ordinary media2 7#b7 producing a large amount of lactic acid in milk2 7#c7 producing1 besides coagulation of casein and splitting up the sugar of milk into lactic acid1 no other change in milk2 7#d7 not producing any indol1 nor peptone1 nor saponification of fat1 nor formation of any gas4 #c4 ,it differs from the above by showing peculiar pink-stained granules1 when stained with methylene blue and showing peculiarly convoluted chains in glucose agar4 #d4 ,the importance of the organism lies in the fact that1 as in the case of ,bacillus bulgaricus1 it kills all pathogenic non-sporing germs and also destroys all proteolytic gas-forming bacilli in milk4 ,in the account of these investigations the following table is given1 showing the amount of lactic acid produced by different lactic acid bacilli in one litre of milk1 in terms of lactic acid--the culture being kept at #cg ,c4 ---------------------------------------- ---------------------------- ,name of the ,after ,after ,after ,after ,after ,bacillus4 #bd #dh #gb #if a ,remarks ,hours4 ,hours4 ,hours4 ,hours4 ,week4 ---------------------------------------- ---------------------------- ,b4 lactis #a4h 444 #aj4jh 444 444 ,observed by rogenes ,hall and ,smith ,b4 coli #a4h 444 #d4gg 444 444 ,observed by communis ,hall and ,smith ,b4 #ab4h #af4e #bj4b 444 #bb ,observed by bulgaricus -4#d -4#d -4#d 444 -4#d ,gabriel ,bertrand and ,weisweller2 the initial acidity of the milk was #d ,matzoon ,long #aj4h #ab4 444 444 444 ,observed by stbschen ,b4 ,dggeli ,strepto- #b4facd 444 444 444 444 ,observed by bacillus ,rist and ,khoury lebenis ,streptothrix #aj4h #a4jh #aa4be #aa4gj #ah4e ,med4 ,coll41 dadhi ,calcutta ---------------------------------------- ---------------------------- ,in different parts of the world sour milk is consumed in great quantities1 and it is stated by ,metchnikoff#ce that the chief food of the natives of tropical ,africa consists of soured milk1 and in ,western ,africa in the region south of ,angola1 the natives live almost entirely on this product1 there being a difference in the curdled milks produced according to the nature of the microbial flora which is introduced4 ,it is stated#cf that in ,servia1 ,bulgaria1#cg and ,roumania there were #ejjj centenarians living in #ahif1 and while many reasons are advanced for such an abnormal condition of affairs1 it seems fairly certain that the sole reason why people in these districts live to such great ages is because of their mode of living and the fact that they live very largely on soured milk4 ,the hygienic conditions throughout these countries are not such as would give the population in the towns and villages any special advantages in the prolongation of life1 and while it may be stated that a pastoral and agricultural life are likely to contribute to longevity1 these conditions would not account for a general tendency to live long in the countries referred to1 more than in any other agricultural area4 ,there are many countries throughout the world in which the pastoral and agricultural existence is general1 but it has not been shown that in these countries life is prolonged4 ,hence the conclusion has been forced upon investigators that the reason is to be found not in the pastoral conditions1 but in the habit which has existed from time immemorial of consuming sour milk as a principal article of diet4 ,there is no curtailment of the use of fermented milks in ,eastern ,europe1 and the methods of preparation at the present day are those which have been carried out from time immemorial4 ,a local observer states that in ,bulgaria yoghourt is made in nearly every household1 especially in the spring and summer4 ,the method of preparation is very simple3 ,the milk is boiled until a quarter of its volume has evaporated1 it is then cooled to #de ,c4 and the ferment added4 ,this ferment is a portion of the yoghourt of good flavour and is called ,maya or ,zakvaska4 ,the vases1 a kind of earthenware pot1 are enveloped in woollen stuff or sheepskin and placed in a warm place near the chimney4 ,in ten hours the yoghourt is made1 and it is preserved in a cold place4 ,the great reputation that the yoghourt has acquired in ,western ,europe has caused this ,maya to become an article of commerce4 ,it is sent out by rail hermetically sealed in tinplate boxes4 ,according to a ,sophia chemist1 the ,maya is employed in the following manner3 ,for a litre of milk it is necessary to take about #aj gr4 of the ferment4 ,this ferment is diluted with three times the amount of water and put into a bowl previously heated with hot water and dried4 ,into this bowl the milk1 previously boiled and cooled to a temperature of #ge to #ej ,c41 is poured2 it is then covered over and put in a temperature of about #cj ,c41 and1 in default of a stove of constant temperature1 the bowl is wrapped round with flannel or a plaid1 and left to curdle for eight to ten hours4 ,it is then ready for consumption4 ,during winter1 curdled milk keeps for several days1 and in summer it becomes sour in from twelve to twenty-four hours4 ,a similar food to the yoghourt is prepared in the ,balkan mountains from sheep's milk under the name of ,urgoutnik4#ch ,the milk is poured into a goat-skin or sheepskin bag1 and a little of the fermented milk added1 and is then left for some hours in a warm place4 ,the milk consumed is replaced by a fresh supply4 ,in some of the ,balkan countries1 they are not content with the fermentation of the milk1 they add a little alum1 which1 under the name of typsa1 is well known for this purpose4 ,the milk attains such a solid consistency that it can be put into a cloth and carried to market4#ci ,the various forms of sour milk which have been described in the foregoing pages may be said to be of the traditional kind1 and with the light of modern knowledge1 it has been possible to determine exactly what constitutes the active principle in use in the milk consumed in these countries1 and1 as we shall see1 this principle has been applied so that1 at the present day1 a pure fermented milk may be obtained in any country1 and there is every reason to believe that should such be adopted as a general article of food1 it would contribute to the prolongation of human existence4 ,it is due to ,metchnikoff1 of the ,pasteur ,institute1 that so much prominence has been given to the use of fermented milks4 ,he gave it as his opinion#dj that senility was caused partly by auto-intoxication or by the poison derived from putrefactive micro-organisms which inhabit the digestive track4 ,these organisms increase with age1 and under certain unhealthy conditions multiply enormously1 particularly in the large intestine4 ,having arrived at this knowledge1 ,metchnikoff set to work to devise some means of combating the influence of these harmful microbes1 and set up the hypothesis that the tendency to longevity which is exhibited in ,eastern countries is due to the consumption of lactic acid organisms in the shape of soured milk4 ,these organisms are more powerful than those of a putrefactive character and inhibit their growth4 ,in the presence of such facts1 says ,metchnikoff1 it becomes exceedingly important to find some means of combating the intestinal putrefaction which constitutes so incontestable a source of danger4 ,such putrefaction is not only capable of producing diseases of the digestive tube--enteritis and colitis--but even of becoming a source of intoxication of the organism in its most varied manifestations4 ,it is some years since ,i proposed to combat intestinal putrefaction and its injurious consequences by means of lactic ferments4 ,i thought the acidity produced by such microbes would be much more effective in preventing the germination of putrefying microbes than the small quantity of acids produced by ,bacillus coli4 ,on the other hand1 ,i had no illusion as to the difficulty sure to be encountered in any effort to introduce lactic microbes into the intestinal flora which has been preoccupied by a multitude of other microbes4 ,to make surer of the result1 ,i chose the lactic microbe1 which is the strongest as an acid producer4 ,it is found in the yahourt 7yoghourt71 which originates in ,bulgaria4 ,the same bacillus has also been isolated from the leben of ,egypt2 and it is now proved that it is found in the curdled milk of the whole ,balkan peninsula1 and even in the ,don region of ,russia4#da ,it is a short step from considerations like these to the adoption of the ,bacillus bulgaricus as the most potent of the various lactic organisms which have been examined1 and which is likely to play such an important rle in the destiny of the human race4 ,the ,bacillus bulgaricus may claim to be the ,bacillus of ,long ,life4 ,,chapter ,,iii ,,the ,,chemistry ,,of ,,milk ,the ,composition of ,milk4--,like all other organic substances1 or those built up in connection with the life processes of plants and animals1 milk is of complex composition4 ,it is also very liable to change--every one is acquainted with its tendency to go bad4 ,this instability is more or less inherent in all highly organised chemical compounds1 and1 indeed1 it seems to be necessary that the materials used in growth and nutrition should be very plastic in a chemical sense1 in order1 e4g41 that the constituents1 say of a plant1 may easily be transformed into the substances of the body of the animal which feeds on it4 ,the perishable nature of milk--the food of young and growing animals--is therefore essential1 so that it may be changed easily into the blood1 bone1 muscle1 etc41 so abundantly required in the early stages of existence4 ,milk is a complete food1 and1 therefore1 naturally it is not a simple chemical compound1 but a mechanical mixture of a number of substances4 ,the present state of chemical knowledge on the subject does not permit of its composition being given in detail1 but for practical purposes1 such as those of measuring its purity and food value1 this is not necessary4 ,a proximate analysis1 in which1 at least1 some of the ingredients are lumped together1 is sufficient1 and has been adopted everywhere by analysts4 ,on this basis the average composition of cows' milk may be stated as follows3 ,per cent4 ,water #hg4ej ,fat #c4ej ,casein and albumen #c4fe ,milk sugar #d4fj ,ash #j4ge ---- #ajj4jj ------ ,the constituents other than water added together form the total solids1 and they amount to #ab4e per cent4 ,per cent4 ,water #hg4e ,total solids #ab4e ---- #ajj4j ----- ,illustration3 ,,the ,,constituents ,,of ,,milk ,in the illustration1 a pint of milk is shown in a glass jar1 and the various percentages of water1 casein1 sugar1 ash1 albumen1 and fat1 which make up its constituent parts1 are shown in separate bottles1 the percentage of each being stated beneath4 ,milk varies a good deal in composition2 the different breeds of cows give varying qualities4 ,the ,short-horn gives large quantities of milk of rather poor analysis1 while the ,jersey yields smaller proportions of very rich milk4 ,during the period of lactation 7the time which has elapsed since the cow gave birth to a calf71 care in milking1 food1 health1 etc41 all have an effect on the quality of the milk4 ,the limits of variation may be stated as follows3 ,per cent4 ,per cent4 ,water #hg4e to #hb4e ,fat #b4e #f4j ,casein and albumen #c4j #d4e ,milk sugar #c4e #f4j ,ash #j4f #j4h ,these figures are extreme1 and it is very seldom indeed that either the minimum or maximum is reached4 ,indeed1 by the regulation laid down under ,clause #d of the ,british ,sale of ,food and ,drugs ,act of #ahii1 when the percentage of solids not fat falls below #h4e per cent41 and fat under #c per cent41 it is assumed that the milk has been adulterated4 ,this regulation is a perfectly just one4 ,while genuine milk may1 in rare instances1 show figures as low as #g4a per cent4 of solids not fat1 or #b4e per cent4 of fat1 the right can hardly be claimed of supplying such an abnormal article to the public as milk of proper quality1 and the dairyman who understands his business1 and wishes to deal fairly with his customers1 can1 by attention to the conditions enumerated above which influence the composition of milk1 entirely avoid the production of such a low-grade article4 ,in the nutrition of both plants and animals large quantities of water are needed4 ,the solids must be supplied in solution or dissolved in the assimilative processes1 and this cannot take place without water1 which also conveys the dissolved solids to the various parts of the economy1 and in the case of animals removes waste materials4 ,for the most part1 water passes through the body unchanged1 but a certain proportion unites chemically with the food materials and assists in their digestion4 ,it is therefore not surprising that seven eighths of milk is composed of water4 ,blood contains a similar proportion1 and this agreement emphasises the fact that milk is a perfectly balanced food4 ,the fat of milk1 which yields cream and butter1 differs in some important respects from other fats4 ,like these1 it is made up chiefly of stearin1 palmitin1 and olein1 but1 in addition1 it contains an abnormally large proportion of compounds of certain of the volatile fatty acids4 ,it is these which give to butter its agreeable flavour4 ,by the methods of ,duclaux1 the following is the approximate composition of butter fat3 ,per cent4 ,stearin1 palmitin1 olein1 and traces of myristin and butin #ia4ej ,butyrin #d4bj ,capronin #b4ej ,caprylin1 caprinin1 and traces of laurin #a4hj ----- #ajj4jj ------ ,myristin occurs in nutmegs2 butyrin in another combination flavours pineapples and rum2 caprinin is found in cocoanut fat1 mutton fat1 and in the offensive odour given off by the goat 7from which the name is derived72 caprylin is a by-product of alcoholic fermentation1 and also occurs in cocoa fat2 laurin is found in sweet bay2 from which it is evident that there are some curious relationships in flavouring materials4 ,fats are very concentrated foods1 furnishing a large amount of energy to the body4 ,at one time they were classed together with starch1 sugar1 and other carbohydrates as heat-producers1 but the distinction which was drawn between the kinds of food which were thought solely to keep up the temperature of the organism1 and those which produced force in work and other forms of bodily energy1 has broken down1 and by direct experiment has been found not to exist4 ,it is usually calculated that one part of fat is equal in food value to about two and a quarter parts of any of the other carbohydrates4 ,milk fat or butter is more digestible than almost any other fat1 and its importance therefore can readily be realised4 ,all the above constituents of milk fat are composed of different proportions of carbon1 hydrogen1 and oxygen1 but milk also contains minute quantities of lecithin1 a fat containing phosphorus in addition4 ,lecithin is also found in the brain and nerve material of animals1 in the yolk of egg1 and in several plants4 ,the nitrogenous constituents of milk--casein and albumen--are usually estimated together1 and they are reckoned as of equivalent food value4 ,the name protein is very commonly applied to the total of these bodies in milk1 or other animal and vegetable foods4 ,they are composed of different proportions of carbon1 hydrogen1 oxygen1 and nitrogen1 with small quantities of sulphur1 while casein contains phosphorus in addition4 ,albumen exists to the extent of about #j4f per cent4 in milk4 ,it is very similar in properties to egg albumen4 ,the coagulum which forms on the surface of milk when boiled is largely composed of albumen4 ,casein is combined with1 and kept in solution by1 lime1 soda1 and calcium phosphate1 and its amount averages a little over #c per cent4 ,the remarkable property possessed by rennet1 of curdling or coagulating casein1 is well known2 rennet is an extract from the stomach of the calf1 and similar principles are present in the stomachs of man and other animals1 so that the coagulation of milk is the first process in its digestion4 ,if milk is gulped down in large quantities it is apt to coagulate in lumps1 and digestion is much interfered with1 but if it is taken hot and slowly1 it coagulates in small pieces which are readily attacked by the gastric juice1 and milk is then one of the most assimilable of foods4 ,nature provides that the milk for young animals is supplied in finely divided streams1 so that coagulation takes place in the best possible way4 ,the proteids are the most important constituents of food2 they are abundant in the blood1 and build up the muscles1 brain1 nerves1 and other bodily structures4 ,besides these mentioned1 milk contains traces of another proteid of similar composition called globulin4 ,the sugar of milk is not found anywhere else4 ,it is a carbohydrate like cane and grape sugar--that is to say1 the hydrogen and oxygen they contain are in the same relative proportions as in water4 ,milk sugar is not so soluble or so sweet as the other sugars4 ,it does not ferment with ordinary yeast1 but certain special yeasts which are made use of in the preparation of keffir1 koumiss1 etc41 have the power of transforming it into alcohol4 ,its most remarkable property1 however1 is the facility with which1 under the influence of certain bacteria1 it is changed into lactic acid4 ,every one is familiar with the souring of milk1 but perhaps it is not so generally known that there are great differences in the results obtained in accordance with the conditions under which the souring takes place4 ,the skilled butter-maker1 by keeping the milk in a cool and cleanly dairy1 obtains a sour milk of a characteristic and agreeable aroma and taste1 which beneficially affect the flavour of the butter produced4 ,on the other hand1 if milk is kept in hot and dirty surroundings1 the development of acidity is accompanied by different bad tastes and odours1 and it becomes unfit for use as a food4 ,in the first case1 the conditions are favourable to the maximum production of the lactic acid bacteria1 and these occupy the field1 and largely prevent the development of the other bacteria which are present--the survival of the fittest in the struggle for existence4 ,in the second case1 the impure surroundings swarm with the germs of many kinds of putrefactive bacteria1 and the high temperature assists these to gain the upper hand4 ,again1 the survival of the fittest1 in the particular conditions4 ,even in cool and cleanly surroundings injurious taints may develop1 especially if the milk has previously been subjected to a journey by road or rail1 as is the case in the modern creamery system1 where the farmers deliver their milk to a central creamery1 where it is made into butter4 ,in such establishments it is the regular practice to kill the germs1 lactic and others1 existing in the milk1 by heating it to a high temperature4 ,this process is called pasteurising1 after the great ,french chemist and bacteriologist who invented it4 ,pure lactic cultures are added to the pasteurised milk1 and the souring process is under exact control1 with the result that butter of uniform flavour and quality is produced4 ,the same method is made use of in making the special sour milk described in this book1 with1 of course1 modifications in the apparatus employed1 to suit the smaller scale in which the manufacture is conducted4 ,the ash is the mineral matter which is left when milk1 previously dried1 is burnt in a crucible4 ,it is a complex mixture1 and1 as we have seen1 it amounts to about #j4g per cent4 of the milk4 ,the process of burning destroys all the organic matter1 and1 at the same time1 alters somewhat the state of combination of the inorganic or mineral elements4 ,attempts have been made from the analysis of the ash to reconstitute the composition of the mineral matter as it exists in the milk4 ,the best known is that of ,soldner1 and the following is his calculation3 ,per cent4 ,sodium chloride #aj4fb ,potassium chloride #i4af ,monopotassium phosphate #ab4gg ,dipotassium phosphates #i4bb ,potassium citrate #e4dg ,dimagnesium citrate #c4ga ,magnesium citrate #d4je ,dicalcium phosphate #g4db ,tricalcium phosphates #h4ij ,calcium citrate #bc4ee ,calcium oxide1 in combination with casein #e4ac ------ #ajj4jj ------ ,the presence of citrates will be noted in this analysis4 ,citric acid1 which gives to lemons their acidity1 and is also found in other fruits1 has been proved to exist in milk to the extent of about #j4b per cent4 ,when alkaline or earthy citrates are burnt or oxidised in the blood1 the citric acid is destroyed1 and corresponding carbonates remain4 ,no doubt the function of citrates in milk is to furnish to the body the earthy and alkaline carbonates which are required in certain of its parts4 ,the mineral constituents of milk have many important functions to perform in the building up and nutrition of the bodily organism4 ,phosphate of lime is the principal constituent of the skeleton1 and the blood must be richly supplied with the alkalies1 earths1 and acids which are comprehended in the ash4 ,milk contains traces of many other substances1 the most important of which are several enzymes which assist in its digestion4 ,general ,properties of ,milk4--,the appearance of milk is known to every one2 it ought to be a pure white opaque liquid1 but very generally it is tinted a cream colour with anatto to give it an added appearance of richness4 ,the average specific gravity is about #a4jca2 or1 to put it another way1 while a gallon of pure water weighs exactly #aj lbs41 a gallon of milk weighs #aj lbs4 #e oz4 ,it freezes at #ca ,f4 and boils at about one third of a degree higher than water4 ,when milk is examined under the microscope1 the fat is found to be distributed through it in a multitude of minute globules varying in size from #a_/af1jjjth to #a_/be1jjjth part of an inch1 and occasionally they are much smaller and also much larger4 ,fig4 #a is a micro-photograph showing the fat globules in whole milk4 ,fig4 #b is a micro-photograph of separated milk1 and ,fig4 #c a micro-photograph of cream1 all under high magnification 7#dej diams472 from these figures the comparative number of fat globules present may be seen4 ,illustration3 ,,fig4 #a4--,micro-photograph of a ,drop of ,whole ,milk1 showing distribution of fat globules4 7,magnified #dej diams47 ,illustration3 ,,fig4 #b4--,micro-photograph of ,separated ,milk1 showing the almost complete absence of fat globules as compared with whole milk4 7,magnified #dej diams47 ,illustration3 ,,fig4 #c4--,micro-photograph of ,cream1 showing agglomeration of fat globules4 7,magnified #dej diams47 ,fats distributed through a watery liquid in this finely divided condition form together what is called an emulsion1 in which the particles of fat are kept apart by surface tension4 ,the specific gravity of milk fat averages #j4ic1 and compared with water weighing #aj lbs41 a gallon of fat would weigh #i lbs4 #e oz4 ,it is thus considerably lighter than the other constituents1 and when milk is left at rest1 the fat globules gradually rise to the top and float there1 forming cream4 ,the difference in specific gravity between cream and milk is taken advantage of in the mechanical separator1 now so much used1 and which makes such a thorough separation between the two4 ,cream is an article of the most varied composition1 according to the ideas of the person who produces it1 but it ought to contain at least #bj per cent4 of butter fat1 and may be made with a much larger percentage if necessary4 ,when cream is agitated in a particular way1 as by churning1 the surface tension of the particles is overcome1 and they run together into a mass which forms butter4 ,the casein of milk is not held in solution in the ordinary sense1 but in a peculiar state of suspension called the colloidal condition1 practically the whole of it remaining behind when milk is filtered through clay filters4 ,it is this state of suspension of the casein which makes milk opaque1 but the opacity is considerably increased by the emulsified fat4 ,the coagulation of the casein in milk by the addition of rennet has already been referred to4 ,acids1 either mineral or organic1 also precipitate it in the form of flakes4 ,skimmed milk is now largely used for the preparation of casein by this method1 and the washed and dried precipitate is used very extensively in the arts for such varied purposes as the manufacture of billiard balls1 paints1 cements1 etc4 ,the clear liquid which separates when milk is curdled with rennet is called whey1 and contains the milk sugar and mineral salts4 ,the sugar is manufactured from it on a limited scale1 and is used as an ingredient in infant foods1 and as a convenient medium in certain medical preparations4 ,in ,sweden a kind of cheese is made from whey1 but the great bulk of it everywhere is used for feeding pigs4 ,the comparative composition of different varieties of milk is given in the following table3 ---------------------------------------- --------------------------------- ,human ,cow ,buffalo ,goat ,sheep ,mare ,ass ,reindeer ,whale ---------------------------------------- --------------------------------- ,water #hh4cb #hg4ge #hb4eg #hf4cd #ha4jh #ij4ch #ij4cj #fg4g #fj4dg ,fat #c4dc #c4dj #g4fc #d4be #g4fg #a4jj #a4cj #ag4a #bj4jj ,protein #a4ee #c4ej #d4fi #d4dj #f4jh #a4ih #a4hj #aj4i #ab4db ,milk ,sugar #f4dd #d4fj #d4cj #d4bf #d4bf #f4bh #f4bj #b4h #e4fc ,salts #j4bf #j4ge #j4ha #j4ge #j4ia #j4cf #j4dj #a4e #a4dh ---------------------------------------- --------------------------------- ,total #ajj4jj #ajj4jj #ajj4jj #ajj4jj #ajj4jj #ajj4jj #ajj4jj #ajj4jj #ajj4jj ---------------------------------------- --------------------------------- ,specific #a4jcb #a4jcae #a4jcc #a4jcc #a4jch #a4jcd #a4jcc 444 444 ,gravity ---------------------------------------- --------------------------------- ,illustration3 ,,fig4 #d is a photograph of two ,petri dishes1 which have been inoculated with ordinary milk 7,a71 and milk that has been subjected to sterilisation 7,b74 ,the whitish bacterial colonies on ,a are due to enormous numbers of organisms1 while ,b is quite free from such growth4 ,for the production of a reliable lactic food1 it is essential that certain precautions as to the treatment of the milk1 and the maintenance of a suitable temperature during the growth of the lactic bacteria1 should be observed4 ,in the first place1 milk immediately after extraction from the cow contains only a few organisms1 but these multiply so rapidly that in a few hours the bacterial content may amount to many millions per ounce4 ,in preparing a pure culture of any specific organism1 then1 care must be taken to destroy all the bacteria that have accidentally found their way into the milk1 inoculating with the organisms it is desired to cultivate4 ,this is best accomplished by heating the milk to the boiling-point of water for about thirty minutes1 by which time almost all the undesirable bacteria have been killed4 ,the milk of the cow differs a good deal from human milk1 and where the former is used for the feeding of children it is usual to add milk sugar to it1 and otherwise alter it to bring its composition more in harmony with the human article4 ,the high concentration of the milk of the reindeer and the whale is noteworthy4 ,perhaps this may be due to the low temperature conditions in which these animals live1 necessitating strong nutriment to enable their young to make proper progress in growth and development4 ,on the other hand1 the milk of the ass is poor in quality1 and probably on this account it is more readily assimilated by those of weak digestion1 to whom it is sometimes recommended4 ,goats' milk is richer than either cow or human milk1 and its nourishing properties are well known4 ,the goat is usually free from tuberculosis and other diseases which affect the cow1 and its milk is therefore a very safe article to use4 ,the ,analysis of ,milk4--,while the analysis of milk can only be made by a competent chemist1 there are a number of simple tests and observations by which any intelligent person can obtain a fair idea of its quality4 ,the taste and smell afford some guide1 as also the general appearance4 ,to judge of the latter1 place some of the milk in a tumbler or other clear glass vessel4 ,if the milk is of good quality it will be quite homogeneous and opaque4 ,any flocculent matter indicates either disease in the cow or that the milk is old and bacteria have multiplied in it and altered its composition4 ,when the milk has stood long enough for the cream to rise freely1 the latter should form a perfectly homogeneous and strongly defined layer on the top4 ,the quantity of cream may be measured in a creamometer1 which consists of a small glass cylinder graduated at the top 7,fig4 #e74 ,it is filled with milk to the top graduation line1 and when the cream has risen1 the percentage quantity of the latter which has separated can be taken off4 ,illustration3 ,,fig4 #e4 ,the ,creamometer ,the colour should be like that of porcelain1 but1 as already stated1 it is a common thing for the dairyman to add a small quantity of anatto or an aniline dye of a similar shade1 to give the milk a rich creamy tint4 ,if the milk is of a reddish colour this may be caused by blood from the udder1 although certain foods1 such as beets1 mangels1 and carrots sometimes give a similar tint4 ,the milk given by cows immediately after calving is called colostrum or biestings1 and is of a yellow or yellow-brown colour4 ,it is much thicker than ordinary milk1 and coagulates in boiling4 ,in dirty byres in which care is not taken in milking1 quite considerable quantities of hairs1 pieces of manure1 and other filth may get into the milk4 ,usually the milk is strained by the dairyman1 but sometimes this is omitted or carelessly done4 ,to test for dirt1 a ribbed glass funnel is useful4 ,get a piece of the finest muslin about twice the diameter of the funnel1 fold over twice1 so that it becomes one quarter of its original size2 open one of the sections and place in the funnel2 pass the milk into this4 ,it will run through quickly and some water may be run into the funnel to clear away the last traces of milk4 ,the filter cloth can then be opened out and any dirt retained will become visible4 ,the apparatus is shown in ,fig4 #f4 ,illustration3 ,,testing-,,glass ,,for ,,extraneous ,,matter ,,in ,,milk4 ,,fig4 #f4--;,a piece of muslin is folded as shown and a measured quantity of milk is passed through the funnel2 from the sediment left in the muslin1 the percentage of extraneous matter may be arrived at4 ,if a glass funnel is not available1 a very small jelly bag can be made of fine gauze and used in the same way4 ,the washing water should be used in small quantities and directed to concentrating the dirt in the apex of the bag4 ,after washing1 the latter can be turned outside in1 to permit of readier examination of the dirt4 ,the bag should be well washed in cold water1 then boiled and dried1 and is then ready for future use4 ,the acidity of milk is a very useful guide to its age4 ,milk has the curious property of being amphoteric1 i4e41 it is both slightly acid and slightly alkaline when fresh4 ,as its age increases1 however1 so does its acidity1 and at a rate varying with the temperature and moisture contents of the atmosphere in which it is placed4 ,old and acid milk is heavily contaminated with bacteria1 a proportion of which are likely to be injurious to health4 ,illustration3 ,,fig4 #g4 ,lactometer and ,test ,tube ,the simplest method of testing the acidity is to procure a few little books of blue and red litmus test papers1 and these can be had from any philosophical instrument maker or laboratory furnisher4 ,the strips of test paper are torn out and dipped in the milk4 ,when the milk is quite fresh it will1 owing to its amphoteric condition1 change the red litmus paper slightly blue1 and the blue litmus paper slightly red4 ,old milk changes blue litmus paper to a bright red because of its decided acidity4 ,the above tests do not indicate if the milk is poor or rich1 but this can be determined by the lactometer1 an instrument for ascertaining in a simple way the specific gravity4 ,the lactometer is shown in ,fig4 #g4 ,it is graduated usually from #be to #cf1 corresponding to specific gravities #a4jbi to #a4jch4 ,it is graduated to degrees and half degrees4 ,sometimes a thermometer is combined with the instrument4 ,the specific gravity rises as the temperature is lowered and decreases with increase of temperature1 so that it is important to make the test at the figure at which the lactometer was graduated1 which is usually #fj ,f4 ,failing this1 an allowance has to be made for higher or lower temperatures4 ,the milk to be tested is well mixed1 and placed in a deep vessel1 and the lactometer placed in it1 holding it at first at an angle4 ,it stands upright and remains deeper or higher according to the specific gravity4 ,the reading is taken on the stem at the level of the milk4 ,as the latter is drawn up a little round the stem1 about a half degree should be added on to get the true figure4 ,thus1 if the apparent reading is #ca1 the true reading may be taken as #ca4e4 ,this is the average figure for good milk1 corresponding to a specific gravity of #a4jcae2 anything above this is all to the good4 ,lower readings mean inferior quality1 the latter being proportionate to the lowness of the readings4 ,the tests are most conveniently made in a glass cylinder 7,fig4 #g71 which may be purchased with the lactometer4 ,as there are many inaccurate instruments in the market1 it is necessary to go to a reputable maker1 because an unreliable lactometer is worse than useless4 ,the following table gives1 in a condensed form1 the allowances to be made when the temperature is above or below the standard 7#fj ,f473 ---------------------------------------- ------------------------------ ,temperature4 ,reading of ,lactometer4 ---------------------------------------- -------------------------------- ,degs4 ,f4 #dj #bc4e #bd4e #be4e #bf4d #bg4c #bh4b #bi4a #cj4j #ca4j #ca4i #cb4h #cc4g #de #bc4h #bd4h #be4i #bf4h #bg4h #bh4f #bi4c #cj4d #ca4c #cb4c #cc4b #cd4b #ej #bd4a #be4a #bf4a #bg4j #bh4j #bi4j #bi4i #cj4i #ca4h #cb4h #cc4g #cd4g #ee #bd4e #be4e #bf4e #bg4e #bh4e #bi4e #cj4d #ca4d #cb4d #cc4d #cd4c #ce4c ---------------------------------------- -------------------------------- #fj #be4j #bf4j #bg4j #bh4j #bi4j #cj4j #ca4j #cb4j #cc4j #cd4j #ce4j #cf4j ---------------------------------------- -------------------------------- #fe #be4e #bf4f #bg4f #bh4g #bi4f #cj4g #ca4g #cb4h #cc4h #cd4h #ce4h 444 #gj #bf4a #bg4b #bh4b #bi4c #cj4b #ca4c #cb4d #cc4d #cd4e #ce4e #cf4e 444 #ge #bf4h #bg4h #bh4h #bi4i #cj4h #cb4a #cc4a #cd4b #ce4b #cf4c 444 444 #hj #bg4d #bh4d #bi4e #cj4g #ca4f #cb4h #cc4i #ce4i #cf4a 444 444 444 ---------------------------------------- -------------------------------- ,thus if the thermometer indicates #dj ,f41 and the lactometer #bi4a1 the true reading at the standard temperature of #fj ,f4 is #ca1 corresponding to a specific gravity of #a4jca4 ,intermediate figures can readily be averaged4 ,care should be taken to wash the lactometer with cold water under the tap1 as otherwise the milk will dry on it and render it inaccurate4 ,,chapter ,,iv ,,handling ,,of ,,milk ,,modern ,,dairy ,,practice ,as we have seen1 the dairy industry is a very ancient one1 and has been intimately associated with the development of civilisation4 ,within historical times dairying has always formed a prominent feature in connection with agriculture1 and the use of milk in one form or another has been common to every civilised nation4#db ,the greatest progress1 however1 in the study of milk has taken place since about the year #ahij1 at which time the dairy industry seems to have attracted the general attention of food specialists and scientific investigators throughout the world4 ,since then it has been considered worth while to enact laws in different countries with regard to the regulation and control of the milk supply4 ,since #aijc there has been an ,international ,dairy ,federation formed1 and it has held conferences at ,brussels1 ,paris1 ,the ,hague1 and ,buda-,pest1 and in #aiaa it will hold a conference in ,stockholm4 ,the ,federation was started in a very humble way in ,brussels1 and owes its origin1 to a large extent1 to a distinguished ,belgian agriculturist1 ,baron ,peers of ,oostcamp1 ,bruges2 but at the present day a general committee composed of representatives of nearly every civilised nation has been formed1 and delegates from such countries attend the ,congresses1 which are held every two years4 ,the literature which has arisen out of these ,international ,congresses has been disseminated in different countries1 and has been instrumental in placing the dairy industry on a thoroughly scientific basis4 ,milk ,supply of the ,united ,kingdom4--,the milk supply of the ,united ,kingdom has steadily grown from year to year1 and in relation to the population works out at fifteen gallons per head4 ,the manner in which these figures are arrived at is shown in the following estimate3 ,the population of the ,united ,kingdom is now about #de1ejj1jjj4 ,the number of cows or heifers in calf or in milk in ,june1 #aiji1 was #c1cfj1fjj2 the number in #aiaj was probably about #d1djj1jjj4 ,of these about #cjj1jjj were heifers that had not yet produced any milk4 ,the actual milking class1 therefore1 comprised about #d1ajj1jjj cows and heifers2 of these1 about #fjj1jjj were heifers that calved in the winter and spring of #aiji-aj1 and #cjj1jjj were heifers that calved in the summer and autumn of #aiaj4 ,the number of cows that produced two or more calves may be taken to be about #c1bjj1jjj2 of these about #fjj1jjj should have produced their second calf in the winter and spring #aiji-aj1 and would be milked as heifers in the summer and autumn of #aiaj2 the number of mature cows from which a full season's supply of milk was obtained during the twelve months from ,june #e1 #aiji1 to ,june #d1 #aiaj1 was apparently about #b1fjj1jjj4 ,a large quantity of milk is yielded during the year by cows sold or lost during the twelve months before the census4 ,possibly ten per cent4 of the milk produced in the twelve months from ,june1 #aiji1 to ,june1 #aiaj1 was yielded by cows that were sold or lost before the census of ,june1 #aiaj4 ,it is estimated that the #c1bjj1jjj cows 7including the #fjj1jjj that up to the winter of #aiji-aj were heifers7 produced1 on the average1 #dd cwts4 7#dhj gallons7 of milk per head in the twelve months from ,june #e1 #aiji1 to ,june #d1 #aiaj2 the #cjj1jjj heifers that calved in the summer and autumn1 #cj cwts4 7#ccj gallons7 per head2 the #fjj1jjj heifers that calved in the winter and spring of #aiji-aj1 #ae cwts4 7#afe gallons71 making the total quantity of milk produced in the twelve months by cows and heifers on the farms1 and that produced calves during the twelve months 7,june1 #aiji-aiaj71 #aeh1hjj1jjj cwts4 7#a1gdf1hjj1jjj gallons71 or about #dbf gallons per head1 and about #djj gallons per head for all the cows and heifers in milk or in calf in #aiaj4 ,there remains to add the milk yielded by the cows that were sold during the twelve months1 and of cows and heifers in feeding pastures that were milked during the twelve months1 ,june to ,june1 #aiji-aj1 and which probably formed one tenth of the whole supply1 making the total supply for the twelve months #agf1ddd1jjj cwts41 or #a1idj1hhd1jjj gallons4 ,this equals #b tons1 or #ddj gallons per head1 crediting the whole supply to the #d1djj1jjj cows and heifers in milk or in calf in ,june1 #aiaj4 ,at #g-a_/d;d4 per gallon the value of milk produced in the ,united ,kingdom in the twelve months was #eh1fjj1jjj4 ,including the value at birth of the calves1 the total value of the produce of the milk-giving class would be about #fb1jjj1jjj4 ,the value of the milk1 butter1 cheese1 and cream sold or consumed in farmhouses would be about #dh1jjj1jjj1 or equal to about #bd per cent4 of the gross annual income of farmers4 ,the average consumption of new milk is about #ae gallons per head of the population4 ,during the twelve months of #aiaa1 the quantity required for this purpose will be about #fhb1ejj1jjj gallons1 or about #ce per cent4 of the total supply2 calves will require about #aj per cent4 of the supply2 the quantity available for butter and cheese will equal about #ee per cent4 of the supply4#dc ,the ,milk ,industry in the ,united ,states4--,in the ,united ,states of ,america1 where the habits of the people are somewhat analogous to those in the ,united ,kingdom1 it is estimated that the milk from five million cows is annually consumed1 which averages twenty-five and one half gallons per year for each person1 or equal to an ordinary sized tumblerful each day4#dd ,such a vast industry1 so intimately associated with the food of the bulk of the people1 naturally invites the closest study1 and1 as a consequence1 the literature on the subject1 which has arisen during the last twenty years1 has been of a voluminous character1 not only from the point of view of practice1 but from that of bacteriology1 chemistry1 and hygiene4 ,a pure milk supply is essential to health1 and it seems unfortunate that the ordinary milk producer should1 in a great many cases1 take up an antagonistic attitude to the scientific methods of handling milk4 ,there is a body of opinion being created1 however1 which is likely to alter this attitude in the next generation1 and this is attributable to the fact that so much excellent work has been done at numerous dairy colleges and institutes in all civilised countries that the dairy industry is emerging from a period of rule-of-thumb procedure to its proper place as one of the technical arts4 ,transmission of ,disease in ,milk4--,it is not to be wondered at that the handling of milk should now be regarded as a technical business1 seeing that milk-borne disease is one of the commonest with which we have to deal4 ,the commoner diseases which have been transmitted by milk are scarlet fever1 typhoid1 diphtheria1 tuberculosis1 sore throat epidemics4 ,others of a more complex character have been traced to the same source of infection1 and the clearest possible evidence has been furnished of the transmission of diseases by means of micro-organisms1 which have contaminated the milk supply4 ,it is therefore necessary to watch over the milk from the source of supply to its consumption4 ,it is primarily on the farm and in the cow-house that methods of handling in a hygienic way should be insisted on1 as microbial contamination increases at a prodigious rate1 and it is the early microbe therefore which does the most damage4 ,the milk in the udder1 for all practical purposes1 may be assumed to be sterile1 and the contamination which takes place originates1 therefore1 from external sources4 ,one of the principal means of infection is from hairs which fall from the cow into the milk1 and many of which are carriers of dangerous micro-organisms4 ,there is also a certain amount of offensive dirty matter which may fall into the milk-pail1 and carry with it undesirable germs4 ,these impurities may1 to a certain extent1 be eliminated by good straining1 but a surer prevention is to have the cow-house perfectly clean and free from dust1 as dust specks are in many cases the vehicles of disease germs4 ,cleanliness is1 in fact1 the essential feature in modern dairying1 not only in the cow-house1 but in the milking utensils1 the drainage1 etc41 and1 above all1 the milker should be of cleanly habits4 ,the flavours of milk sometimes arise from the absorption of evil-smelling gases in the cow-house1 or from a peculiar taint from certain roots and feeding stuffs1 and in such a case it is desirable that aration should take place in a fresh clear atmosphere1 so that oxygenation may have the effect of eliminating and destroying the foreign odours and flavours which may be present4 ,if this process of aration is carried out at blood heat1 the result is generally highly satisfactory4 ,milk ,management4--,there have been many excellent tables of rules published for the management of dairies in different countries1 but they are necessarily framed within certain limitations which apply to all4 ,the following is an excellent set1 which put concisely the conditions necessary to be observed in the modern cow-house3 #a4 ,the cow should be sound--no disease should exist in the animal4 #b4 ,the feed should be good and free from aromatic substances4 ,if these aromatic foods are used1 they should be employed according to those methods which will not cause odours or flavours to appear in the milk4 #c4 ,the cow should be groomed1 and hair about the udder preferably clipped4 #d4 ,the udder should be moistened during milking4 #e4 ,the milker should be a neat1 tidy person4 #f4 ,the milker should be free from disease1 and should not come in contact with any communicable disease4 #g4 ,the milker's clothes and hands should be clean while milking4 #h4 ,the pail should be sterilised4 #i4 ,the stall should be such as to reduce the amount of disturbance of dust and dirt4 #aj4 ,there should be good light1 good ventilation1 and good drainage in the cow-house4 #aa4 ,the cow-house should always be kept clean4 #ab4 ,feeding and bedding1 unless moist1 should be done after milking4 #ac4 ,a dustless milking-room is desirable4 #ad4 ,milk should not stand in the cow-house4 #ae4 ,if milk is arated1 it should be done before cooling and in pure air4 #af4 ,the sooner the milk is cooled after milking the better4 #ag4 ,keep the milk as cold as possible when once cooled4#de ,the supply of milk is conducted1 to a large extent1 by towns' dairies1 which depend for their supplies upon the dairy farm in the country1 and it is obvious that a certain period of time must elapse1 in the generality of cases1 before a town's dairy receives its supply in the ordinary course1 and this constitutes the greatest difficulty in modern dairy practice1 owing to the liability of the milk to absorb bacteria1 which during transit may multiply enormously4 ,the multiplying of bacteria in milk at different temperatures is easily demonstrated1 and the result of this has been stated in various forms many times over4 ,as a graphic means1 however1 of showing the increase that takes place in the numbers of germs present1 and the consequent product of acidity1 the table below by ,conn may be given4 ,the consequent result of the increase in bacteria is the production of lactic acid1 which produces the souring so familiar in milk which has been kept in the household at a high temperature4 ,numbers of ,bacteria per c4cm4 in ,milk kept at ,different ,temperatures4 ---------------------------------------- ---------------------------------- ,number ,in #ab ,in #ab ,in #ej ,in #ej hrs4 or at ,no4 hrs4 ,no4 hrs4 at hrs4 at hrs4 at hrs4 at time of curdling to curdle to curdle ,outset #ej ,f4 #gj ,f4 #ej ,f4 at #gj ,f4 at #ej ,f4 at #gj ,f4 ---------------------------------------- ---------------------------------- #df1jjj #ci1jjj #bdi1ejj #a1ejj1jjj #edb1jjj1jjj #aij #ef #dg1jjj #dd1hjj #cfj1jjj #abg1ejj #gib1jjj1jjj4cf hrs4 #bhi #cf #ej1jjj #ce1jjj #hjj1jjj #afj1jjj #b1efj1jjj1jjj4db hrs4 #agb #db ---------------------------------------- ---------------------------------- ,what actually happens is that the lactic acid is produced by the breaking up of the milk sugar1 and the appearance of this sourness is an indication that a period has been reached in the age of the milk which may be described as being--unwholesome4#df ,it is necessary1 therefore1 for the town's milk dairy to be equipped in such a way as to deal promptly with the milk supply4 ,we have seen that the milk should first of all be arated at blood heat1 so as to liberate objectionable odours1 after which it should be cooled to as low a temperature as possible1 by means of well water4 ,when these operations have been performed on the farm1 milk should be sent as rapidly as possible to the distributing towns' dairies1 and should be transported in refrigerated waggons1 cooled preferably with ice1 during the journey4 ,on arrival at the town dairy1 it will be necessary to pasteurise the milk--that is to say1 the milk should be heated to such a temperature as will destroy any pathogenic organisms which may be present1 and the pasteurising temperature should therefore be in excess of the thermal death-point of all such organisms4 ,pasteurisation owes its origin to ,pasteur1 and has become an adopted method throughout the dairy industry1 and there are many mechanical devices termed pasteurisers 7see ,fig4 #h7 which are used for the carrying out of this particular operation4 ,the form of one of these is that of a vertical jacketed cylinder with paraboloidal surface1 around which steam is made to pass1 so as to maintain the temperature at about #agf ,f4 ,milk is allowed to flow in at the bottom of the paraboloidal surface1 and is caught by mechanical agitating arms1 which revolve at a given speed1 and by this action milk is distributed centrifugally over the paraboloidal surface1 and is forced out by the same action1 at the top of the apparatus1 after being heated4 ,illustration3 ,,pasteuriser ,,fig4 #h4--,the milk enters from the bottom and circulates to the top of the inside cylinder1 which is paraboloidal in construction4 ,it is heated as it passes through the apparatus1 and is discharged at the top at a temperature of #agf ,f4 ,the centrifugal action is sufficient to raise the milk some three to four feet1 through a tube1 and this is taken advantage of so as to cause the milk to flow over a conical cooler1 described as a primary cooler1 and in which water is made to circulate4 ,as the hot milk descends over the conical cooler it gives up most of its acquired heat to the water1 and1 in practice1 is reduced in temperature to within #d of the temperature of the water4 ,below this primary cooler is fixed a cooler of the same size and shape1 which is termed a secondary cooler4 ,in it1 brine at a temperature of about #ce ,f4 is circulated from a refrigerating machine1 and1 as the milk falls over the secondary cooler1 it is cooled to a temperature of about #dj ,f41 when it may be looked upon as being pasteurised and free from all pathogenic organisms1 in which state it will keep for a considerable length of time4 ,it is desirable that the milk should1 as soon as possible after the cooling takes place1 be delivered to the consumers1 and be kept under cool conditions1 either in bottles or in a closed vessel covered over with muslin1 so as to keep out specks of germ-laden dust4 ,briefly speaking1 the foregoing is an outline of what is carried on in the ordinary dairy practice4 ,there are many modifications of this practice1 such as the introduction of regenerative heaters1 so as to utilise a portion of the heat of pasteurisation1 which would otherwise be wasted4 ,in some cases1 again1 it is considered necessary to conduct the primary and secondary cooling over coolers furnished with mantles1 so that the atmospheric bacteria which are everywhere present should be shut off from the falling milk4 ,ordinarily1 however1 the equipment for a town's dairy consists of3 #a4 ,steam-boiler to generate steam for pasteurising1 scalding1 etc4 #b4 ,motive power1 which may be either a steam-engine1 gas-engine1 or electric motor4 #c4 ,refrigerating machine1 which is used for supplying cold brine to the secondary cooler4 ,in many cases it is also used for cooling a room in which the milk and cream are stored4 #d4 ,milk-receiving tank4 #e4 ,milk-strainer4 #f4 ,pasteurising apparatus1 and primary and secondary coolers4 ,such a plant is necessary in order to conduct an ordinary town dairy business in anything like a hygienic way1 and is designed only for the handling of milk intended for domestic consumption4 ,there are times when another plant might be necessary1 such as a plant for the separation of milk1 or for utilising it for the production of butter or cheese1 such operations being subject to the fluctuations in the milk supply4 ,it is sometimes desirable also to use up an excess of milk for cheese or butter-making2 hence it is necessary to provide such apparatus as has been indicated4 ,preparation of ,soured ,milk4--,the foregoing description has been given in some detail1 as showing the ordinary practice1 and we now come to consider how it can be modified so as to provide for the production of soured milk4 ,it may first of all be premised that within the next few years the preparation of soured milk as an ordinary production of the dairy will be universal1 and will form a part of the ordinary dairy practice4 ,the apparatus1 therefore1 which is necessary is one of considerable interest to all who are engaged in the dairy industry4 ,as will be seen from the chapter describing the preparation of soured milk in the dairy1 this process can be conveniently carried on1 so as to utilise the plant which is at present in general use4 ,the milk can be received in the same way1 pasteurised and cooled to about blood-heat1 after which its preparation as soured milk is a very simple matter1 and only requires a certain amount of careful attention4 ,for the keeping of soured milk1 a cold room cooled by a refrigerating machine would be desirable1 so as to maintain the fermented milk at a low temperature and prevent over-fermentation4 ,apparatus has been designed so as to handle soured milk on a large scale1 and one of the machines is shown on the illustration 7see ,fig4 #i74 ,it is simply a jacketed cylinder with a cover and an agitating gear4 ,the inside of the machine is nickel-plated1 and there is an arrangement whereby the cooling may be done rapidly1 through a coil inside the jacket1 this coil being connected to the brine circulation of the refrigerating machine4 ,illustration3 ,,continuous ,,apparatus ,,for ,,the ,,production ,,of ,,large ,,quantities ,,of ,,soured ,,milk ,,fig4 #i--,this apparatus is made by the ,dairy ,machinery and ,construction ,company of ,shelton1 ,conn41 ,u ,s ,a4 ,the milk is agitated inside a jacketed cylinder1 where it is allowed to incubate at about blood heat4 ,the milk can be rapidly heated and also rapidly cooled by means of this apparatus4 ,the machine is filled with milk containing three per cent4 of fat1 which has been previously pasteurised to about #aij ,f41 and cooled down to about #ij ,f42 at this point the pure culture of ,bacillus bulgaricus is introduced1 and the agitator is kept working1 so as to mingle it thoroughly with the milk4 ,the agitator is then stopped until the acidity shows a test of #j4i to #a4j per cent41 when the agitator is again started1 and cold brine from the refrigerating machine is turned on to the cooling pipes1 so that the product is thoroughly broken up1 and cooled down to #dj ,f4 ,the milk is then transferred to a bottle-filling machine 7,fig4 #aj71 poured into bottles and hermetically sealed1 after which it is ready for consumption4 ,when it has to be kept for any time it should be placed in a cold room where there is a temperature not higher than #dj ,f4 ,the process1 therefore1 is a simple one1 and lends itself to the ordinary dairy business1 without involving any great expenditure on account of a new plant4 ,,chapter ,v ,,the ,,bacteriology ,,of ,,fermented ,,or ,,soured ,,milk ,a ,,chapter ,,for ,,students ,during the last few years much work has been done in investigating the action of various classes of organisms--bacteria1 yeasts1 and moulds--upon milk and its products4 ,while1 however1 the attention of the dairyman has been chiefly directed to the propagation of acid-producing organisms and the use of pure cultures of lactic acid bacteria in their relation to butter and cheese making1 a new sphere in micro-biology has been disclosed by the study of the effects caused by the combined growth of two or more different classes of organisms in milk and the consequent production of lactic1 alcoholic1 and gaseous fermentations4 ,the simultaneous occurrence of these fermentative changes is responsible for the formation of such beverages as keffir1 koumiss1 milk-wine1 etc4 ,it has therefore become essential1 in connection with the study of new developments in the milk industry1 that we should make a more intimate acquaintance with the bacteriology of the ferments involved4 ,keffir 7kephir1 kifyr1 kiafyr1 kephor1 kyppe7 is the name given to an acid1 slightly alcoholic drink1 which for many centuries has been prepared by the nomadic tribes in the ,caucasus4 ,the characteristic fermentation is induced by the addition of so-called keffir grains4 ,these are yellow or golden-yellow1 warty1 and furrowed flakes or nodules1 the former varying in size from that of a rice grain to that of a bean1 while the latter are often about an inch across and one eighth of an inch thick4 ,bearing in mind the fact that the preparation of keffir has been carried on for many centuries1 it is not surprising that the origin of these grains should be surrounded by myths4 ,the belief is prevalent among the ,mohammedan tribes of the ,caucasus that keffir grains were1 in the first instance1 presented by ,allah1 as a sign of immortality1 to one preferred tribe4 ,others hold that1 in past ages1 they were found by shepherds growing on a shrub in the ,caucasian highlands2 while1 according to ,skolotowski1#dg they were originally found adhering to the walls of an oaken vessel used for the preparation of airam4 ,this is a soured milk beverage similar to keffir1 but possessing a weaker alcoholic fermentation1 and prepared from goats' milk by the addition of pieces of calf's stomach4 ,this would undoubtedly serve to introduce various species of lactic acid bacteria1 and will be referred to in the portion dealing with soured milks4 ,keffir is prepared by the ,caucasians from cows'1 sheep's1 or goats' milk1 and the operation is carried on in large leathern tubes or bottles4 ,after the addition of the grains or seeds to the milk the vessel is placed in a cool chamber1 and the fermentation is allowed to proceed for one or two days1 by the end of which time the normal fermentation is at an end4 ,during this period the keffir grains have increased enormously in size1 assume a bright yellow colour1 and lose their sour buttery smell4 ,previous to the removal of the fermented liquid1 a portion of the bottle is firmly bound from the rest by a stout cord1 and the greater portion of the remaining keffir is quickly removed for use1 thus avoiding1 as far as practicable1 any outside infection4 ,after the addition of fresh warm milk the cord round the end of the bottle is removed1 and the old and new milk thoroughly mixed for a time in order to ensure uniform inoculation of the new milk for the next fermentation4 ,during the winter months the leathern vessels are often placed in the sunshine1 so that the temperature remains at #fa to #fe ,f4 ,the necessary agitation of the vessel is said to be supplied in the form of kicks by passers-by or by the children during their play4 ,the beverage prepared in this way is so gaseous in character that it is often blown forcibly from the vessel during removal1 and possesses1 according to ,podowyssozki1#dh a very acid taste4 ,during any interruption in the preparation of keffir in the above manner1 the grains are taken out1 and after having been well washed in clean water1 are spread out on a clean cloth to dry in the sunshine4 ,they thereby assume a characteristic cheesy or buttery odour and become rather darker in colour4 ,thorough desiccation is essential in order to prevent subsequent mouldiness or disease of the grain4 ,in ,european countries the grains are subjected to a preliminary soaking in water for five to six hours and then placed in four to five changes of milk1 each change having a duration of two to three hours4 ,as soon as the grains commence to rise to the surface of the milk1 they may be used for the actual preparation4 ,to this end1 a small quantity of the grain is added to freshly boiled milk and allowed to stand for eight to twelve hours at a temperature of #ee-fb ,f4 with agitation of the flask every two hours4 ,by this time the milk1 now known as ,sakwaska1 has become abundantly inoculated with the organisms essential to the fermentation1 and after the removal of the grains1 may be poured into well-corked flasks for the secondary brew4 ,the flasks should be kept at a lower temperature for twenty-four to forty-eight hours1 by which time the product is ready for consumption4 ,according to the temperature and length of period to which this subsequent fermentation is allowed to proceed1 the resultant keffir is more or less acid and gaseous4 ,the grains may again be used for starting a fresh portion of milk1 and a regular supply obtained in this manner4 ,well-fermented forty-eight-hours-old keffir should be an effervescent beverage with prickling and acid taste and a consistency and smell similar to sour cream4 ,large1 persistent bubbles should form on the surface of the liquid and the casein be present as an extremely fine flocculent precipitate which remains suspended for a considerable time4 ,from the third day there ensues a gradual peptonisation of the casein4 ,if the temperature at which the secondary fermentation has occurred should be higher than #gb ,f41 or if the milk has not been sufficiently agitated1 then the casein will be present in the form of porous small flakes1 which on shaking form a fine emulsion4 ,the chemical changes undergone by the milk during the preparation of keffir are confined almost exclusively to the milk sugar4 ,as already stated1 a slight peptonisation occurs in old samples1 but this depends very largely upon the method of preparation and purity of the culture4 ,hammersten#di and ,essaulow#ej show1 however1 that this is not a concomitant of normal fermentation4 ,according to ,hammersten1 normal keffir contains-- ,per cent4 ,water #hh4bf ,fat #c4ce ,casein #b4ih ,lactalbumen #j4bh ,peptones #j4je ,milk sugar #b4gh ,lactic acid #j4ha ,alcohol #j4gj ,ash #j4gi ,in no case should the acid be higher than #a4j per cent41 and the alcohol more than #j4ge per cent4 ,biology of the ,keffir ,grain4--,the first communication on the biology of the keffir grain seems to have been made by ,kern4#ea ,he regarded the grain as a zogloea composed of bacilli and yeasts1 the latter being regarded as the ordinary beer yeast 7,saccharomyces cerevisse71 while to the former he gave the name of ,dispora caucasica4 ,as the name indicates1 this bacillus possesses two polar spores1 and germination of these proceeded in the same manner as with ,bac4 subtilis4 ,as1 however1 pure cultures of the organisms were not made1 and the descriptions and illustrations made by ,kern fail to show any distinctive characteristics1 it seems probable that accidental confusion with other organisms must have occurred4 ,illustration3 ,a ,,milk ,,filling ,,apparatus ,,fig4 #aj--,where soured milk is handled on the large scale1 a special filling apparatus for bottles is desirable1 and the soured milk supply should be under cover as shown4 ,this apparatus is made by the ,dairy ,machinery and ,construction ,company4 ,krannhals#eb succeeded in isolating ten different keffir bacteria among which were several sporulating bacteria4 ,here too it is impossible to attach any importance to the results1 as the artificial preparation of keffir1 by means of these bacteria1 was not attempted4 ,beijerinck#ec studied the organisms constituting keffir grains and attached prime importance to the occurrence of two organisms1 viz41 7a7 a yeast1 ,saccharomyces kefir1 which was capable of inverting milk sugar by means of an enzyme 7lactase7 and afterwards fermented the products with the formation of alcohol and carbon dioxide1 and also 7b7 a non-motile non-sporulating bacterium1 afterwards ,lactobac4 caucasicus4 ,the latter1 when cultivated on gelatine1 gave rise to tough warty colonies about #a_/dj in4 diameter1 and was regarded as one of the lactic acid bacteria found in milk which has been incubated at #gg to #ij ,f4 and afterwards incubated at a higher temperature1 #ajj to #ajd ,f4 ,scholl#ed isolated three different organisms1 of which a yeast inverted milk sugar for the lactic acid bacteria1 while ,dispora peptonised the albuminoid matters4 ,adametz#ee failed to isolate ,dispora1 and came to the conclusion that ordinary lactic bacteria and yeasts played the most important part in the fermentation4 ,essaulow found in keffir grains six different organisms--yeast cells1 cocci1 short thick bacilli1 bent bacilli1 long threads1 and motile bacteria4 ,the two latter would seem to be ,bacillus subtilis1 while the others may be regarded as ,bacterium acidi lactici 7,hueppe71 ,bacterium arogenes1 and ,streptococcus lacticus 7,grotenfeldt74 ,pure cultures were insufficient to produce keffir1 while mixed cultures of ,bacterium acidi lactici and yeasts were effective4 ,freudenreich1#ef to whom we owe a record of very carefully executed experiments1 could not arrive at a satisfactory explanation of the rle of ,bacillus caucasicus4 ,this organism is described as being #e-f long and #a thick1 slightly motile1 and possessing bright refractive spots at the poles of the bacilli4 ,it is extremely difficult to cultivate1 and forms flat1 small greyish colonies of irregular outline4 ,the bright refractive spots above referred to are1 however1 granules taking the usual stains quite readily1 and not spores as supposed by ,kern4 ,freudenreich also found three other organisms--a yeast and two streptococci4 ,the yeast1 to which he gave the name ,saccharomyces 7,torula7 keffir1 forms small oval or roundish cells #b-c wide and #c-e long4 ,the optimum temperature would seem to be about #gb ,f42 the maximum #hb ,f4 ,this organism is unable to ferment milk directly1 but is able to decompose maltose and glucose with gas production4 ,it does not coagulate milk1 but imparts to it a characteristic taste and is unable to withstand desiccation for more than a few days4 ,of the two streptococci isolated1 ,streptococcus a resembles organisms of the group ,streptococcus lacticus in appearance1 but is able to ferment milk1 with weak acid and gas production1 and is capable of inducing coagulation4 ,illustration3 ,,fig4 #aa4--,section through a ,kephir ,grain--highly magnified4 ,contrary to what one would expect in an organism existing in keffir grains1 this streptococcus is as little able to withstand desiccation as the above-mentioned yeast4 ,streptococcus b forms smaller cells as well as smaller colonies than ,streptococcus a1 but produces more lactic acid and more gas1 and retains its vitality after desiccation4 ,the relation of these four organisms is1 according to ,e4 von ,freudenreich1 as follows3 ,sacch4 keffir is unable to ferment directly milk or lactose1 so that its growth must be preceded by that of ,streptococcus b4 ,streptococcus a does not seem to play this part1 but1 unlike ,streptococcus b1 is able to coagulate milk on its own account4 ,by the combined action of the yeast and the two streptococci1 then1 milk can be coagulated1 milk sugar inverted1 acid and gas produced by the streptococci1 while gas and alcohol are formed by the activity of the yeast4 ,the rle of ,bacillus caucasicus is unknown1 but it would seem to play a part in the formation of the keffir grain itself4 ,by means of mixed cultures of the above organisms ,freudenreich was successful in obtaining a fermented product possessing in all respects the characteristic properties of normal keffir4 ,on the other hand1 experiments to induce the formation of keffir grains gave negative results1 but in this respect the cultural characteristics of ,lactobacillus keffir would seem to give promise of success in the synthesis of the keffir grain4 ,fig4 #aa is a photo-micrograph of an extremely thin section through a keffir grain1 after a preceding treatment with saffranin4 ,the matrix is composed entirely of long thin bacilli 7,bacillus caucasicus71 while the peripheral portions1 which are more deeply stained1 consist to a large extent of dense masses of yeast cells with occasional streptococci4 ,in a normal grain the latter organisms are present on the surface or in the cavities and grooves of the grain1 and only to a less extent in the matrix4 ,nikolaiewa#eg claimed to have isolated a hitherto unknown bacillus capable of coagulating milk by acid production1 ,bacterium caucasicum1 not identical with1 but related to ,freudenreich's ,bacillus caucasicus1 and also a torula4 ,although no experiments were carried out1 ,nikolaiewa asserts that this organism forms the matrix of the grains4 ,he was able to produce a beverage resembling keffir1 just as ,freudenreich and ,essaulow did with entirely different organisms1 but his product would appear to have been slightly too acid and to have lacked the characteristic aroma of the normal product4 ,in the course of an extensive series of experiments ,kuntze#eh found the following organisms3 7a7 ,true lactic acid forming bacteria1 ,streptococcus acidi lactici 7,grotenfeldt74 7b7 ,bacteria of the group ,bacterium acidi lactici 7,hueppe7 and ,bacterium lactis arogenes4 7c7 ,various torula and yeast species4 7d7 ,two species of butyric acid bacteria1 ,bacillus esterificans and ,bacillus keffir 7,kuntze74 ,his conclusions are3 #a4 ,in any case the presence of a yeast capable of directly fermenting milk sugar is not essential4 #b4 ,the significance of the presence of yeast lies in the fact that stimulation of the lactic bacteria occurs2 further1 the yeast exerts a regulating influence upon the rapidity of the fermentation proper4 ,the variety is of minor importance1 provided always that the yeast does not produce an unpleasant flavour4 ,by the use of mixed cultures of ,bacillus esterificans1 ,bacillus keffir1 and ,streptococcus acidi lactici1 and a keffir yeast1 ,kuntze obtained a product that possessed to the fullest degree all the characteristic properties of a normal keffir4 ,in such cultures he was successful in obtaining the formation of keffir-like grains4 ,keffir fermentation is1 according to ,kuntze1 the result of the action of various organisms4 ,during the initial stage butyric acid fermentation takes place1 but is prevented from becoming predominant by the action of the keffir yeast4 ,simultaneously a true lactic acid fermentation proceeds and eventually gives place to a subsequent secondary production of butyric acid4 ,finally1 then1 we have a certain amount of unison in the results obtained by ,freudenreich1 ,essaulow1 ,nikolaiewa1 and ,kuntze4 ,these show that1 for the production of a characteristic keffir1 specific organisms are not essential1 provided always that those used possess1 either individually or collectively1 the essential capacity of acidifying1 coagulating1 and fermenting the milk4 ,for the growth of normal grains the presence of a matrix-forming organism1 such as ,bacillus keffir1 is indispensable4 ,illustration3 ,,fig4 #ab--,streptococcus lacticus 7,grotenfeldt7 growing on lactose-agar1 stained by ,gram's method4 7 ,x #ijj diams47 ,diseases of ,keffir ,grains4--,according to the age and the previous treatment to which keffir grains have been subjected1 the vitality of one or more of the organisms constituting the grain may have been impaired4 ,the results of ,freudenreich have shown that ,saccharomyces keffir and ,streptococcus a are unable to withstand desiccation for more than a few days1 and this is sufficient to account for the frequent failures to obtain normal keffir from the grain4 ,further1 grains succumb to a mucilaginous disease2 the cavities become filled with a slimy fluid1 and the grains are covered with mucilaginous matter4 ,they lose their elasticity and become brittle or mealy1 but large grains appear to be more subject to this fault than do the small ones4 ,such grains should be disinfected by immersion for a short time in two per cent4 salicylic acid solution1 followed by drying in the sun1 whereby they are completely regenerated4 ,another disease consists in the predominance of certain butyric acid bacteria which impart an unpleasant rancid taste to the keffir 7,podowyssozki74 ,this is generally attributed to the use of rich milk1 or too high a temperature during preparation4 ,koumiss4--,another product of the combined action of lactic acid and alcohol-producing organisms is called koumiss1 kumys1 milk-wine1 lac fermentation1 or vinum lactis4 ,in the steppes of ,southern ,russia and ,asia1 as we have seen1#ei it is prepared chiefly from mares' milk1 but occasionally from that of camels and jennets4 ,the name is said to be derived from that of a tribe mentioned by ,xenophon and ,pliny1 viz41 the ,kumanen1 by whom its preparation was practised4 ,after the war with the ,tartars in #abae its use was adopted by the latter people1 and eventually spread to the ,turkomanen1 ,kalmucks1 ,khirgiz1 ,mongolians1 etc4 ,rubruck1 in #abec1 records the use of a fermented drink--kosmos--prepared from mares' milk1 and about the same time ,marco ,polo mentions the occurrence of a milk-wine1 chumis or chemius1 among the ,tartars4 ,the fact that the ,tartars were seldom ill1 and were almost invariably free from lung troubles1 led to an influx of visitors from surrounding countries1 until finally its use spread to ,russia1 ,austria1 and ,germany4 ,at the present time the best koumiss is that produced in the province of ,orenburg2 but specially equipped koumiss establishments1 under the control of physicians1 exist in ,odessa1 ,samara1 ,ufa in the ,urals1 and other districts4 ,the curative properties of koumiss have long been recognised and its use is indicated in cases of indigestion1 chlorosis1 scurvy1 tuberculosis1 etc4 ,rubinsky states that1 among the nomadic tribe1 of ,khirgiz and ,kalmucks1 a special leathern bottle 7,turssuk1 ,orroth1 or ,soaba7 is used for the preparation of koumiss1 while wooden tubs 7,tschiljak7 similar in shape to the old-fashioned churn are used by the ,bashkirs1 and in koumiss establishments4 ,the fermentation is induced by the addition of koumiss to fresh mares' milk1 in proportions which vary according to the cleanliness observed in the actual preparation4 ,where the process is carefully controlled1 one part of koumiss to ten parts of milk is often used1 but where gross infection from outside sources takes place one part of koumiss to three parts of milk is taken4 ,the mixture is stirred at frequent intervals1 and stored at a temperature of #gc-ij ,f4 ,weak koumiss is obtained after twenty to twenty-four hours in winter and twelve to fourteen hours in summer1 but is scarcely ever consumed immediately1 as it possesses a strong purgative action4 ,it is generally poured into bottles 7bottled koumiss72 or allowed to remain in the tubs 7tschiljak koumiss72 in the former case the fermentation is anarobic1 in the second it is arobic4 ,storage of the koumiss upon ice or in a cellar is necessary since medium koumiss is converted to strong koumiss in twelve to sixteen hours at ordinary temperatures1 while at the lower temperature this occurs only in two to four days4#fj ,according to ,biel1#fa either old koumiss or the dried sediment from old koumiss may be used for the initial inoculation4 ,it may also be prepared by the repeated inoculation of mares' milk with soured cows' milk until a fermenting product is obtained4 ,koumiss may be prepared by a method stated by ,allik#fb to be in general use in the ,caucasian health-resorts4 ,one part of beer-yeast is added to four to ten parts of fresh mares' milk 7according to the strength of product required71 and after thorough mixture of the two liquids the whole is allowed to ferment at a temperature of #gj to #gb ,f4 for two days4 ,one part of this first product is then added to five parts of fresh cold milk1 and allowed to stand three to four hours at #ge to #gg ,f4 ,it is then poured into bottles1 and after the expiration of another three to four hours is stored away in a cellar at about #de ,f4 ,this koumiss may be used at any time from one to five days 7generally two to three7 after bottling according to the strength desired or prescribed in each individual case4 ,the changes undergone during fermentation consist in a vigorous gas and acid production accompanied by alcohol formation and coagulation of the milk4 ,the coagulum exists in an extremely fine state of division1 and the liquid froths violently on the bottle being opened4 ,it has a full pleasant acid taste1 but should not contain more than one per cent4 acid and two per cent4 alcohol4 ,the specific gravity of koumiss is #a4jjh to #a4jbj at #fj ,f4 ,appended is an analysis of two different samples of koumiss3 ---------------------------------------- ----------- ,prepared from ---------------------------------------- ----------- ,mares' ,milk4 ,separated ,cows' ,milk4 ---------------------------------------- ----------- ,per ,cent4 ,per ,cent4 ,water #ia4ece #hh4icc ,fat #a4bgd #j4hed ,nitrogenous bodies #a4iac #b4jbe ,sugar #a4bec #c4ajh ,ash #j4bic #j4ddd ,carbon dioxide #j4hgf #a4jbg ,alcohol #a4hej #b4fdg ,lactic acid #a4jjf #j4gif ,glycerine 4444 #j4aff ---------------------------------------- ----------- ,fleischmann#fc gives a formula for preparing an artificial koumiss from separated cows' milk1 water1 cane sugar1 and milk sugar1 with the addition of distillery yeast4 ,needless to say1 this product must possess some of the characteristic by-flavour of the yeast employed1 and is less suitable than koumiss prepared by the aid of a lactic yeast4 ,schipin investigated the fermentation of koumiss and found three distinct organisms4 ,rubinsky in a recent article threw much light on the phenomena of koumiss fermentation4 ,according to him1 koumiss contains almost invariably four different organisms1 viz41 koumiss yeast1 koumiss bacterium 7,lactobacillus71 ,streptococcus lactis 7,lister71 ,bacterium arogenes1 and occasionally ,bact4 caucasicum 7,nikolajewa74 ,for the preparation of normal koumiss only the two former organisms are required2 they exceed in number any of the other organisms whose presence in the dairy is unavoidable4 ,the presence of the two latter organisms is favourable to the production of good koumiss1 as1 by inducing a preliminary lactic fermentation1 they tend to inhibit the growth of undesirable extraneous bacteria1 etc4 ,in medium and strong koumiss they die out on account of the amount of lactic acid formed 7#a74 ,koumiss yeast possesses strongly differentiated protoplasm1 but lacks any cultural characteristics4 ,abundant growth occurs in milk1 and lactic acid 7#j4c71 alcohol1 carbon dioxide1 albumens and peptones1 volatile acids1 and aromatic substances are formed4 ,koumiss bacterium is related to the ,lactobacillus of various other fermented milks1 and is similar to ,bac4 acidophilus1 and possesses like these a distinct polymorphism 7branched cells1 long and short bacilli1 etc474 ,it is non-sporogenous1 has an optimum temperature of #ij to #ig ,f41 and possesses cultural characteristics similar to those of the rest of the ,lactobacilli4 ,the by-products of koumiss yeast appear to favour the growth of the koumiss bacterium1 as this organism1 like the other ,lactobacilli1 is favourably influenced by the presence of small quantities of peptone1 alcohol1 and acid4 ,the organisms found by ,schipin consisted of a species of ,saccharomyces and two bacilli1 ,bacillus acidi lactici and a non-sporulating bacillus4 ,the latter organisms coagulate milk at #ih ,f41 but not at room temperature1 and although a minute description of cultural characteristics is not given it would seem to be related to ,bacillus or ,lactobacillus caucasicus4 ,leben ,rab or ,leben 7,laban47--,this is a beverage prepared largely by the ,egyptians1 and differs from keffir1 as does matzoon1 in possessing a characteristic aroma and taste4 ,it differs also from the former by having only a very weak alcoholic fermentation1 and by the coagulum being coarse and lumpy instead of being extremely fine4 ,it is made from buffaloes'1 goats'1 or cows' milk by the addition of roba 7or old leben7 to the previously boiled and cooled fresh milk4 ,the use of leben is many centuries old1 and it is used in ,egypt as in ,arabia for medicinal purposes1 although that of the ,syrians and ,arabians is said to differ from that of the ,egyptians and ,algerians4 ,the fermentative changes occurring in the formation of the ,egyptian leben have been investigated by ,rist and ,khoury1#fd and also by ,guerbet1#fe who found that five organisms were normally present4 ,these comprised a chain-forming bacillus 7,streptobacillus71 a second smaller bacillus 7,bacillus lebenis71 a diplococcus1 a saccharomyces1 and a mycoderma4 ,of these five organisms1 it would appear that four live in metabiosis1 the streptobacilli and bacilli hydrolyse the milk sugar1 the components of which are split up by the yeast to alcohol and carbon-dioxide4 ,the alcohol thus formed1 together with the glucose formed by hydrolysis1 are eventually converted to acid or combusted by the mycoderma species4 ,the leben thereby assumes the sharp1 unpleasant flavour met with in old samples4 ,the diplococcus merely produces acidification and coagulation of the milk4 ,rist and ,khoury were able1 by the use of these organisms1 to produce normal leben1 especially when the true yeast was allowed to grow in the milk for some time before inoculation with the other organisms was made4 ,some of the half-civilised tribes of ,siberia1 the ,tartars and the ,burgaten1 prepare a strong alcoholic beverage1 arak or ojrn1 from fermented milk4 ,this is really a product of distillation1 and contains seven to eight per cent4 of alcohol and volatile fatty acids4 ,illustration3 ,,fig4 #ac--,photo-micrograph of preparation from ,armenian soured milk 7,matzoon74 ,this is related to ,yoghourt1 and contains1 as will be seen from the above photo1 yeasts1 streptococci1 diplococci1 and a bacillus with the morphology of ,bacillus bulgaricus4 ,this1 and similar foods1 owe their peculiar properties primarily to the presence of ,bacillus bulgaricus 7type ,a1 ,white and ,avery71 and only in a lesser degree to the yeasts and lactic streptococci4 ,matzoon4--,this is a drink used largely in ,western ,asia1 and is similar in character to keffir1 but has a peculiar taste which distinguishes it from all other fermented milks4 ,according to ,weigmann1#ff it is prepared from buffaloes'1 goats'1 or cows' milk1 and is used partly as a means of souring milk for butter-making and also as a lactic food1 eaten with spoons4 ,in the same way buttermilk produced from milk which has been previously ripened by matzoon is used as a beverage4 ,finally1 the coagulum 7than7 of such buttermilk is strained off1 and1 after being pressed1 is mixed with meal and dried by exposure to the sun's rays4 ,the preparation of matzoon is in many respects very similar to that of keffir and koumiss1 but differs by inducing a comparatively weak alcohol fermentation4 ,in common1 too1 with yoghourt1 the prevailing temperature is much higher than is required for keffir and koumiss4 ,in regard to the biology of matzoon1 the occurrence of various organisms has been recorded4 ,emmerling#fg isolated1 in addition to a yellow pigment-forming organism1 ,bacillus subtilis1 ,bacillus lactis acidi1 and several fungi1 a small micrococcus capable of hydrolysing milk- and cane-sugar4 ,the organism produces and without gas formation1 or peptonisation of the medium4 ,of the nine yeasts isolated from matzoon by ,lindner#fh and ,kalantharianz1#fi three were able to ferment milk sugar without previous hydrolysis1 while two others1 by the simultaneous production of lactic acid and fruit esters1 gave to the matzoon its characteristic taste and aroma4 ,yoghourt and ,soured ,milk4--,yoghourt is another fermented milk1 and is related to the matzoon of ,armenia1 the gioddu of ,sardinia1 and the leben of ,egypt4 ,after a preceding boiling and reduction of the volume of the milk1 inoculation of the mass is made by the addition of a small quantity of old culture1 and it is then allowed to sour at a comparatively high temperature4 ,a moderately compact1 jelly-like coagulum is thus formed1 while keffir and koumiss possess a liquid consistency4 ,the fermentation necessary for the two latter products only proceeds1 too1 at a much lower temperature1 at which yeasts play an important part4 ,according to ,guerbet1 yoghourt incubated for ten hours at #aac ,f4 contained #j4cd per cent4 lactic acid and #j4jab per cent4 alcohol4 ,luerssen and ,khn#gj came to the conclusion that yoghourt contained chiefly a mixture of ,bacillus bulgaricus1 diplostreptococci1 and a granule bacillus1 so called on account of its granulated appearance after treatment with methylene blue4 ,according to these authors1 the first two organisms were found in each of eight samples of maya 7young yoghourt7 and of yoghourt itself1 but the occurrence of the granule bacillus in plate cultures was by no means regular4 ,in addition1 yeasts were found in almost every sample examined1 but were regarded more as accidental infections rather than as essential to the formation of a typical product4 ,the combined action of the three organisms already mentioned gave rise to a product closely resembling normal yoghourt4 ,piorkowski#ga subjected ,bulgarian maya to examination and associated himself with ,metchnikoff#gb in finding three species1 a streptococcus1 a diplococcus1 and a specific organism to which he gave the name ,yoghourt bacillus4 ,similar results were also obtained by ,grigoroff4#gc ,piorkowski's ,yoghourt bacillus is similar in form to ,bacillus subtilis1 but does not sporulate1 nor does it liquefy gelatine4 ,young individuals are stained by ,gram's method2 older individuals are1 however1 ,gram negative4 ,the optimum temperature is #aab ,f4 ,kuntze attempted to isolate the organisms mentioned by ,luerssen and ,khn1 and by plate culture procured growth of a spore-forming bacillus similar to ,weigmann's ,bacillus matzoon4 ,to this organism is attributed the power to impart a specific taste to the matzoon1 but as growth is comparatively slow1 it can only be of significance in determining the quality of the curd and cheese prepared from this product4 ,cultures were also obtained which resembled in general character those of the organism described by ,luerssen and ,khn as ,bacillus bulgaricus and named by ,kuntze ,bacterium ,w4 ,granule formation was transient in this culture1 and the organisms eventually became inactive4 ,further analysis of maya gave cultures of the granule bacillus1 but these passed over from the type forming irregular colonies 7see ,figs4 #ad1 #ae1 #af7 to that producing smooth colonies4 ,further1 although the granule formation persists largely in milk1 the organisms soon revert to the non-granular type if cultivated on agar4 ,by the use of the ,gram-,weigert stain organisms from a several-days-old culture on beer-wort-agar gave an interesting reaction4 ,the bacillar threads are in places ,gram-negative1 in others ,gram-positive1 and bear small club-like swellings 7see ,fig4 #ad74 ,results similar to these were also obtained with cultures of ,bacillus matzoon 7,weigmann and ,grbner7 and also with ,bacillus acidophilus4 ,neisser's method of staining failed to give such good effects by the examination of fresh maya1 as did an alcoholic aqueous solution of methylene blue in showing up the granules of the organisms4 ,again1 ,grixoni#gd found1 but did not isolate1 a similar granule-forming organism 7,bacterium sardous7 in ,sardinian gioddu4 ,as already mentioned in the description of leben1 ,rist and ,khoury found a long bacillar lactic ferment 7,streptobacillus lebenis7 which also exhibited the irregular greyish white hairy colonies and high optimum temperature characteristic of this group4 ,on account of the similarity in form1 staining reactions1 temperature requirements1 and cultural growth of the organisms described by ,emmerling1 ,dggeli1 ,weigmann1 ,grixoni1 and ,rist and ,khoury1 ,kuntze is inclined to regard them as belonging to one single group of lactic ferments4 ,according to him the granule formation is rather variable1 and may be induced or suppressed by cultural methods4 ,not only do organisms of this group produce far more acid than the normal lactic bacteria2 they are also more resistant to acid1 and are able to develop in milk to which #j4e per cent4 hydrochloric acid has been added4 ,a comparatively high percentage of alcohol seems to encourage growth1 and this was obtained in milk containing #d per cent4 alcohol4 ,this would no doubt tend to explain the phenomenon observed by ,kuntze that milk is not so rapidly fermented by organisms of this group as when cultures of diplococci and yeasts are added4 ,since organisms of this group would seem to be widely distributed1 the question of their natural habitat arises4 ,luerssen and ,khn were unsuccessful in their search for such organisms in ,knigsberg milk1 but ,leichmann records the occurrence of a long bacillus 7,bacillus lactis acidi7 in milk that had spontaneously soured at #aab to #abj ,f4 ,this organism1 too1 showed characteristic growth on agar media1 and produces lvo-rotatory lactic acid4 ,the examination of calves' stomachs showed1 according to ,kuntze1 only occasional long bacilli1 but inoculation of sterile milk and incubation at #ajj ,f4 with repeated over-inoculation gave a culture showing the characteristic granule reaction 7see ,figs4 #ah and #bj74 ,although plate cultures made direct from calves' stomachs do not exhibit the regular contours generally shown by the granule bacillus1 yet this growth may be induced by preceding cultivation in lactose bouillon to which #j4e per cent4 acetic acid has been added4 ,a similar organism1 ,bacillus acidophilus1 was isolated from calves' manure by means of this acetic bouillon1 as was also a diplostreptococcus which resembled very closely the typical lactic acid streptococcus4 ,this resemblance was made all the more striking by the fact that they were capable of coagulating milk at a temperature of #ii to #ajd ,f4 ,since these organisms are present in large numbers in manure and also in the digestive tract of ruminants1 it would seem probable that their occurrence is not without significance for the operations of cheese manufacture4 ,according to ,jensen1 the practice of applying farmyard manure to ,swiss meadows has been regarded as absolutely essential to the production of cheese of the best quality2 while1 on the other hand1 the application of artificial manures would seem to have been responsible for an increase in abnormal cheese4 ,kuntze found further that by the combined inoculation of sterile milk with the diplostreptococcus and the granule bacillus from calves' stomachs1 together with a yoghourt yeast1 he was able to obtain a product possessing a taste and aroma little different from normal yoghourt4 ,during their investigations upon the ripening of ,swiss hard cheese1 ,freudenreich and ,jensen#ge isolated five varieties of lactic acid bacilli1 and were able to show that one of these1 especially ,bacillus casei ,greek3 e1 was of the greatest importance for the production of good cheese4 ,this organism has been found by ,thni to be present in rennet tablets1 while a related variety1 ,bacillus casei ,greek3 d1 was found in fresh calves' stomachs4 ,unfortunately1 staining tests with these organisms were not carried out1 so that no data are available in regard to the presence of granules4 ,the photo-micrographs of these organisms show the small clubs and true-branched forms4 ,the presence of these diplococci and bacillar lactic ferments in the intestinal tract of ruminants and horses might possess some importance for the preparation of yoghourt in bags or tubes made from the stomachs of these animals4 ,finally1 ,moro#gf has isolated an acidophilic organism from the dejecta of infants which resembles closely1 both in manner of growth1 resistance to acids1 true branching1 and temperature optimum1 the granule bacillus and related forms4 ,this group of sixteen illustrations 7,figs4 #ad to #bi71 showing various aspects of the ,yoghourt bacillus and others of a cognate nature1 is taken from the ,centralblatt fr ,bakteriologie of ,jena4--,l4 ,m4 ,d4 ,illustration3 ,,fig4 #ad4--;,granule ,bacillus from ,yoghourt4 ,shredded preparation of a fresh skim-milk culture at #cg ,c4 for six hours4 ,stain3 aqueous methylene blue4 7,enlarged #a3ejj47 ,in ,figs4 #ae and #ag will be noticed the chain arrangement of the bacillus1 which1 in spite of the supposed data of ,luerssen and ,kuhn1 will be generally noticed in the granule bacillus4 ,illustration3 ,,fig4 #ae4--;,granule ,bacillus from ,yoghourt1 cultivated after the usual ,agar method1 for twenty-four hours at #cg ,c4 ,stain3 aqueous methylene blue4 7,enlarged #a3ejj47 ,illustration3 ,,fig4 #af4--;,granule ,bacillus from ,yoghourt4 ,agar ,milk ,sugar ,culture cultivated for forty-eight hours at #cg ,c4 ,below is the true branching1 above1 the distorted involution form4 ,this production of involution forms occurs chiefly in old cultures1 and is an indication of degeneration4 ,stain3 aqueous methylene blue4 7,enlarged #a3gjj47 ,illustration3 ,,fig4 #ag4--;,bacteria ,w4 from ,milk1 cultivated twenty-four hours at #cg ,c4 ,methylene blue4 7,enlarged #a3ejj47 ,the similarity in the pictures ought to serve as a proof of the near relation of the granule form and non-granule varieties4 ,illustration3 ,,fig4 #ah4--;,agar ,milk ,sugar ,culture4 ,from the original ,bulgarian ,yoghourt4 ,in the centre1 and beneath1 the characteristic hairy irregular colonies of the granule bacillus 7,bacillus bulgaricus group71 to the left1 the smooth contoured yeast colonies4 ,the colonies of the former organism always remain microscopic in size4 7,incubated several days at #bj to #be ,c4 ,magnified ,x #aj47 ,illustration3 ,,fig4 #ai4--;,agar ,milk ,sugar ,culture4 ,surface colony of granule bacillus from calf's stomach4 ,the great resemblance this colony bears to those formed by the granule bacillus from ,yoghourt will be apparent4 ,this fact1 as well as close agreement in other cultured features1 induced ,kuntze to place these organisms in one group4 7,incubated two days at #cg ,c4 ,magnified ,x #ajj47 ,illustration3 ,,fig4 #bj4--;,agar ,milk ,sugar ,culture4 ,deep-lying colony of granule bacillus from calf's stomach4 ,the form of the colony is often determined by the relative presence or absence of air4 7,two days at #cg ,c4 ,enlarged about #a3ej47 ,illustration3 ,,fig4 #ba4--;,agar ,milk ,sugar4 ,colony of ,bacterium ,w4 from ,yoghourt 7non-granular variety of the granule bacteria1 as far as possible identical with ,luersen and ,khn's ,bacillus bulgaricus71 of a cubical branching-out form4 ,according to ,kuntze1 the granule formation of this and related organisms is variable1 while ,white and ,avery regard it as a constant characteristic4 7,incubated two days at #cg ,c4 ,magnified x #ej47 ,illustration3 ,,fig4 #bb4--,two colonies of ,bacillus acidophilus from calf's manure4 ,agar ,milk ,sugar ,culture4 ,with this organism1 also1 we have conformation to one type of colony1 while1 in other respects1 temperature requirements and production1 etc41 we have close agreement with the granule bacillus 7,bacillus bulgaricus74 7,two days at #cg ,c4 ,enlarged about #a3ej47 ,illustration3 ,,fig4 #bc4--;,beer-wort ,gelatine4 ,fourteen-days-old colony of ,yoghourt yeast4 7,enlarged about #a3ej47 ,illustration3 ,,fig4 #bd4--,shredded preparation of the ,bulgarian original ,yoghourt4 ,stain3 aqueous methylene blue4 ,granule bacillus1 diplostreptococci1 and yeast4 7,see also other photo-micrographs of ,yoghourt4 ,enlarged #a3gj47 ,illustration3 ,,fig4 #be4--;,granule ,bacillus from ,yoghourt4 ,cultivated in skim milk in twenty-four hours at #cg ,c4 ,stain3 aqueous methylene blue4 7,enlarged #a3ej47 ,by means of this staining treatment the presence of granules 7not spores7 can be easily detected4 ,treatment with fuchsine fails to bring out these formations4 ,illustration3 ,,fig4 #bf4--;,bacteria ,w41 ,agar ,milk ,sugar ,culture4 ,cultivated twenty-four hours 7knobs1 clubs74 ,stain3 ,gram's method coloured with aqueous fuchsine afterwards4 7,enlarged #a3fjj47 ,illustration3 ,,fig4 #bg4--;,bacteria acidophilus from calves' manure1 isolated by means of bouillon as acid as vinegar4 ,shredded out of the usual ,agar culture4 ,twenty-four hours at #cg ,c4 ,stain3 aqueous methylene blue4 7,enlarged #a3gjj47 ,illustration3 ,,fig4 #bh4--,mucus from calf's stomach inoculated into milk after eight transferrings4 ,shredded preparation cultivated in milk for twenty-four hours at #cg ,c4 ,diplostreptococci and granule bacillus4 ,stain3 aqueous methylene blue4 7,enlarged #a3ejj47 ,illustration3 ,,fig4 #bi4--;,diplostreptococcus from ,yoghourt4 ,pure culture in skim milk4 ,a comparison of the illustrations will show how close a resemblance exists between bacteria found in the mucous membrane of calf's stomach and those occurring in ,yoghourt4 ,in fact1 by the combined action of granule bacilli1 and of diplostreptococci from calf's stomach1 together with a ,yoghourt yeast1 it is possible to prepare normal ,yoghourt4 ,in a review of the literature of the subject of soured milks1 ,makrinoff suggests the adoption of the two names1 ,streptobac4 lebenis viscosus and ,streptobac4 lebenis non-viscosus1 for the organisms of the so-called ,bulgaricus group1 and known at present as ,bacillus-bulgaricus1 ,streptobac4 lebenis1 ,bacillus of ,massol1 ,granule bacillus1 ,bact4 ,mazun1 ,bac4 lactis acidi1 etc4#gg ,white and ,avery#gh have made a comparative study of a large number of varieties and species of lactic acid bacteria of the above type obtained from various fermented milks and milk tabloids4 ,their descriptions are so detailed and their conclusions are so important that we give them at length4 ,according to this work1 the whole of the thermophilic lactic acid bacilli of the so-called ,bulgaricus type may be divided into two sub-types1 ,a and ,b4 ,the ,cultural ,characteristics of the ,bacillus ,bulgaricus ,group ,the cultural characteristics of all the strains of ,bacillus bulgaricus 7granule bacillus7 are as follows3 ,in ,whey ,agar4--,all strains exhibit wide variation in size1 #b to #ej long and about #a broad4 ,almost all individuals are intensely ,gram-positive1 and show regularity of outline4 ,all strains show involution form1 exhibiting vacuoles1 and often show empty cell membranes4 ,the latter are ,gram-negative1 and vary greatly in both dimensions as well as in form4 ,all strains show tendency to chain formation1 some being arranged in chains of six to twenty-five segments1 which may contain both ,gram-positive and ,gram-negative individuals4 ,type ,b exhibits ,gram-negative spherical bodies varying from #j4be to #a in size1 adhering to the sides of some of the ,gram-negative individuals4 ,in ,whey4--,in this medium there is a marked tendency toward degeneration and involution4 ,in the early stages of incubation1 at #ajj to #aab ,f41 the bacilli are uniform in size and intensely ,gram-positive2 in succeeding stages the irregular1 vacuolated1 inflated1 and ruptured forms predominate4 ,between the eighteenth and twenty-fourth hours of incubation at #aab ,f4 the strains of type ,a develop oval to kidney-shaped nodules attached to a stem extending from the cell substance4 ,as the incubation is prolonged these nodules increase in size1 often measuring #a to #b in length2 this nodule formation occurs at the expense of the cell protoplasm1 and appears to be a marked characteristic of growth in whey4 ,cultures of type ,b do not form nodules or clubs1 but small spherical bodies more or less securely attached to the cell wall are seen4 ,again1 type ,a assumes the form of small bacilli in chains1 while type ,b strains develop to a greater length and exist almost exclusively as single isolated forms4 ,true branching has been observed in strains of type ,b4 ,in ,milk4--,in milk there is a tendency to thread-formation consisting of four to ten segments in the case of type ,a1 while type ,b shows longer and more curved forms4 ,with increasing age of the culture there also appears to be increase in the length of the organisms4 ,all strains are non-motile1 non-sporogenous1 and non-capsule-forming4 ,staining ,reactions4--,all strains are readily stained by the usual aniline dyes4 ,a4 ,gram's ,method4--,young individuals give an intense reaction with this stain2 old bacilli are easily decolourised1 and degenerate forms are always ,gram-negative1 while single individuals have been observed which showed gradation from one pole of the cell to the other4 ,b4 ,loeffler's ,methylene ,blue4--,according to the behaviour of the organisms studied1 a separation into two types appears possible1 type ,a being uniformly impregnated1 while type ,b shows distinct differentiation4 ,the cell body is seen to contain a varying number of round to oval bodies or granules4 ,this is the appearance already mentioned by ,dggeli1 ,luerssen and ,khn1 and ,kuntze1 and from which the granule bacillus derives its name4 ,in opposition to the observations of ,kuntze1 the occurrence of granules was not found to be variable2 it was1 indeed1 so constant as to constitute a distinguishing characteristic between the two types4 ,the organisms of this group are difficult to cultivate1 and freshly isolated growth is obtainable only on media containing whey1 malt1 or in milk4 ,they grow equally well under arobic or anarobic conditions4 ,the optimum temperature for growth is #aac to #aae ,f42 growth is fair at #he ,f41 slight at #ge ,f41 and does not take place at #fh ,f4 ,colonies on whey agar are round to irregular1 greyish white1 curled and filamentous1 often streaming1 and in a few cases smooth and even in structure4 ,gelatine is not liquefied4 ,there is no surface growth on gelatine stab-cultures4 ,along the stab the growth is filiform1 beaded1 with subsequent horizontally projecting ramifications4 ,milk is coagulated in eight to eighteen hours at #aab ,f41 and is the most favourable medium for growth4 ,i am indebted for this group of illustrations 7seventeen in number7 to the editor of ,bacteriotherapy1 ,new ,york1 ,u4,s4,a4--,l4,m4,d4 ,illustration3 ,,fig4 #cj--,photo micrograph of preparation made from ,yoghourt1 showing yeast cells1 large lactic diplococci1 small slender bacilli and many large bacilli possessing the morphology of ,bacillus bulgaricus4 ,yeast cells are almost invariably found in native ,yoghourt1 but do not appear to be essential to the production of a tropical beverage4 ,indeed1 they would seem to be responsible for the unpleasant astringent taste often met with in old samples of this product4 ,illustration3 ,,fig4 #ca--,photo micrograph of smear from ,greek ,curdled ,milk called ,giaourti1 and showing yeast cells1 long bacilli and a mould 7,oidium lactis71 possessing very large elongate cells4 ,the presence of the latter is very undesirable1 as it rapidly combusts the lactic acid1 digests the casein1 and imparts a strong unpleasant cheesy flavour to the beverage4 ,type ,a produces #b4g per cent4 to #c4g per cent4 inactive lactic acid in milk1 while type ,b produces only #a4b per cent4 to #a4f per cent4 lvo-rotatory lactic acid in milk4 ,there is a small quantity of acetic1 formic1 and succinic acids formed4 ,the conclusions of ,white and ,avery are3 ,i4 ,a review of the morphological culture and biochemical features of the lactic acid producing bacilli from yoghourt1 matzoon1 and leben1 appears to justify their classification as a single group4 ,,ii4 ,this group would seem to be identical with ,bacterium caucasicum 7,kern74 ,,iii4 ,the significant variations exhibited by these bacilli in regard to the presence or absence of granules demonstrable by differential stains1 the degree of lactic acid production1 and the nature of the acid produced1 suggest a division into two different types--the true type ,a1 and the paratype ,b4 ,quite recently ,hastings and ,hammer#gi recorded the isolation from milk of an organism producing more acid than either ,bacterium coli commune or ,bacillus lactis acidi4 ,it is characterised by possessing a high optimum temperature1 and by the limited conditions under which it grows on nutrient media4 ,on this account these investigators suppose it to be related to those described in the paragraphs on fermented milks1 leben1 matzoon1 etc41 and which are regarded by ,kuntze as being identical4 ,similarly ,boutroux#hj found #a4e per cent4 acidity produced in a solution containing albuminous matter and glucose2 while ,richet#ha states that with the addition of gastric juice to milk as much as four per cent4 acidity may be formed4 ,after storing samples of milk for eight days at #ajj ,f41 ,koning#hb found #b4ce per cent4 and #b4e acid2 while similar samples stored at #fj to #fb ,f4 for the same period only developed #j4i per cent4 ,heinemann#hc records the production of #c4j per cent4 acid in milk incubated at #ajj ,f42 and ,jensen states that ,bacillus casei ,greek3 e is capable of developing #b4g per cent4 lactic acid4 ,dr4 ,h4 ,b4 ,hutchinson1 bacteriologist at ,rothamsted ,experimental ,station1 has also been successful in isolating a bacillus from ,english market milk resembling in every particular those classified by ,white and ,avery as type ,a4 ,illustration3 ,,fig4 #cb is a photo-micrograph of soured milk inoculated with a tablet containing viable and pure cultures of ,bacillus bulgaricus1 and incubated for seventy-two hours4 ,these tablets constitute a valuable means of preparing soured milk for therapeutic purposes4 ,illustration3 ,,fig4 #cc is a photo-micrograph of milk inoculated with a ferment tablet in which ,bacillus bulgaricus is no longer viable1 and the only growth obtained is that of an organism allied to the ,bacillus subtilis 7,hay bacillus7 group4 ,such milk would be absolutely without value4 ,it will thus be seen that organisms related to those of ,oriental and ,occidental milk beverages are present in conditions where it is impossible for them to attain to any active growth4 ,the same class of organism has also been found in many cases in butter and cheese throughout the ,united ,states4 ,of recent years the consumption of milk fermented by these organisms has been introduced more or less successfully into all ,european countries4 ,this custom is due1 as we have seen1#hd to a very great extent to the announcement of ,metchnikoff#he that the action of such organisms in the alimentary tract conduce to a prolongation of life4 ,moro found that the dejecta of children contain large numbers of ,bac4 lacidophilus and ,bac4 bifidus1 but1 as age advances1 the bacterial flora of the intestines tends to change4 ,the number of acid-producing organisms gradually becomes less1 and other bacteria capable of producing far-reaching decomposition of albuminoid matter tend to increase4 ,working on the assumption that senility is partially due to the absorption of by-products formed from albuminoid food by the decomposing or putrefactive bacteria mentioned1 ,metchnikoff instituted a search for organisms capable of suppressing the growth of the putrefactive bacteria4 ,it has long been known that milk allowed to become sour will keep for a considerably longer period in hot weather than if lactic bacteria had not grown4 ,this preservative action of lactic acid also comes into play in the manufacture of sauerkraut and in the preservation of meat by immersion in sour milk4 ,illustration3 ,,fig4 #cd4--,photo-micrograph of smear of culture of ,bacillus bulgaricus1 recommended by ,metchnikoff for use in cases of intestinal auto-intoxication4 ,unlike the ferments of normally soured milk1 which are sometimes indifferent1 or even injurious1 in their action1 this bacillus is capable of growth at blood heat1 and1 by producing much larger quantities of lactic acid than such organisms as ,streptococcus lacticus1 ,bacillus coli commune1 or ,bacteria lacticus arogenes1 inhibits the multiplication of bacteria responsible for the putrefaction of albuminoid food in the intestines4 ,bienstock has shown that the growth of ,bac4 putrificus is inhibited by the action of ,bact4 coli commune1 which is capable of setting up a slight lactic acid fermentation4 ,bact4 coli commune1 however1 gives rise to substances of an injurious character1 and1 although present very abundantly in the intestinal tract1 it may by reduced almost entirely by the active growth of lactic acid bacteria4 ,this fact is of great value to the cheese-maker1 since by the addition of a lactic acid culture 7starter7 to milk before renneting1 gas-producing bacteria such as ,bact4 coli may be checked in growth4 ,since the ordinary lactic acid bacteria such as ,streptococcus lacticus1 ,bac4 lactis acidi1 and others1 are incapable of growth at blood temperature1 it appeared necessary to procure cultures of lactic bacteria able to grow at temperatures of #ajj ,f4 to #aab ,f4 ,such an organism was found in ,bulgarian soured milk 7yoghourt71 and was considered pre-eminently adapted to this purpose4 ,as has been shown in the preceding paragraphs1 this organism is merely one of a large group of bacteria found distributed in the intestinal canal of many domestic animals1 in manure1 and in ordinary market milk4 ,it is then not surprising that the introduction into the intestinal tract of bacteria of the type ,bulgaricus in the form of tabloids has not met with any decided success4 ,although it was considered to be merely necessary to introduce the desired type of organism into the body1 and the amount of lactic acid taken into the system by the administration of soured milks was looked upon as of secondary importance1 yet1 it would seem1 in the light of recent investigations1 that benefits derived from a soured milk regimen are attributable in part to a chemical as well as a purely bacterial action4 ,this receives support from the fact that soured milk beverages prepared by the use of ordinary lactic bacteria1 distinct from those of the ,bulgaricus type1 often exert a beneficial influence upon human beings even although the organisms responsible for the fermentation are incapable of growth at blood temperature4 ,it may be mentioned in conclusion that cultures prepared by the use of organisms of the type ,streptococcus lacticus combined with ,bac4 bulgaricus possess a more agreeable flavour and aroma than those prepared from a pure culture of ,bulgaricus alone4 ,illustration3 ,,fig4 #ce--;,bacillus bulgaricus1 showing the cultures in ,english cow's milk4 7,magnified #dej diams47 ,illustration3 ,,fig4 #cf--,photo-micrograph of pure culture of ,bacillus bulgaricus4 ,the administration of cultures of this organism is indicated in all cases of intestinal ailments1 caused by the excessive growth of proteolytic bacteria1 and consequent putrefaction of foods in the alimentary tract4 ,by the formation of large quantities of lactic acid1 a state of asepsis is ensured1 which is particularly valuable in cases of operations on the abdomen and intestines4 ,illustration3 ,,fig4 #cg4--,photo-micrograph of smear of combined culture of ,bacillus bulgaricus and ,bacteria paralacticus4 ,this double culture possesses an advantage over single cultures in that1 while the characteristic disinfecting action of the former is retained1 any secondary action of the growth of this organism upon the milk-fat is checked by the growth of ,bacillus paralacticus1 thus ensuring the production of a more palatable product4 ,,chapter ,,vi ,,the ,,preparation ,,of ,,soured ,,milk ,,in ,,the ,,house ,there is no great difficulty in making soured milk at home3 the necessary operations are quite simple1 but at the same time they must be conducted with precision and care1 otherwise the results may be unsatisfactory and disagreeable2 there may even sometimes be danger in badly prepared sour milk4 ,it is always an advantage in such matters to understand the reason of things1 and a few notes on the surrounding conditions1 and what has to be accomplished1 may be of assistance to the would-be experimenter4 ,the majority of intelligent people are now acquainted with the fact that the germs of bacteria are to be found everywhere on the surface of the earth1 in air1 and in water1 and that they are the sole cause of the decay of all manner of perishable articles4 ,the distribution is unequal--bacteria are much more plentiful where there is decaying matter--in dirty houses1 sewage1 or other contaminated water1 etc4 ,milk is a splendid food for bacteria1 and numerous varieties multiply in it exceedingly1 and many of these are injurious1 producing putrefactive changes which render the milk unwholesome1 even poisonous in some cases4 ,others are beneficial1 and are absolutely necessary for the souring of milk for making butter or cheese and for the ripening of the latter4 ,the soured milk which is the subject of this book is the work of certain lactic-acid-producing bacteria1 and the problem we have before us is to encourage the growth of the latter to the uttermost and to exclude the others4 ,as bacterial germs are present in the air and readily sow themselves into any medium with which they come in contact1 the first consideration is to get good fresh milk which has been as little exposed to the air as possible4 ,the second is to conduct the experiment where the germs are fewest1 and in cleanly surroundings1 far removed from decaying matter and free from taints and smells4 ,illustration3 ,,fig4 #ch4--,photo-micrograph of smear of one-month culture of ,bacillus bulgaricus4 ,in spite of its age1 the culture is perfectly free from any foreign organisms1 which would otherwise lower its value for the preparation of soured milk1 and might1 indeed1 make it directly injurious4 ,illustration3 ,,fig4 #ci4--,photo-micrograph of culture of ,bacillus bulgaricus in malt4 ,in cases of acute enteritis1 where milk cannot be supported1 the lactic bacilli may be cultivated in malt1 and administered to the patient in this form1 with occasional doses of syrup of malt1 in order to induce a vigorous growth of the lactic ferments in the body4 ,illustration3 ,,fig4 #dj4--,photo-micrograph of smear from milk that had been allowed to sour spontaneously4 ,ordinary market milk is always subject to infection from the air1 milking vessels1 manure1 etc41 and from these sources a mixed bacterial flora arises1 with the result that the milk exhibits curdling1 acidity1 gaseous fermentation1 or mould growth1 after being stored for a short time4 ,this is due to the action of sush bacilli1 diplococci1 yeasts1 and moulds as are shown in this illustration4 ,however fresh the milk may be1 it will contain useless or injurious bacteria1 and we must get rid of these before attempting to introduce those whose growth we wish to encourage4 ,this is effected by heat4 ,all the living bacteria and most of the germs are killed at temperatures somewhat under the boiling point4 ,having sterilised the milk in this way1 it is necessary1 as far as possible1 to prevent the entrance of fresh germs from the atmosphere1 and we therefore let the milk cool down in covered dishes4 ,when the temperature descends to about #ajj ,f4 the culture of the special bacteria is introduced1 the covers are replaced1 and the milk vessels maintained at or near this temperature for twelve hours1 when the soured milk is ready for use4 ,it is not necessary to use fresh culture every time--a little of the soured milk will take its place1 and this may be repeated as many as fourteen times before it is necessary to start off again with a fresh culture4 ,a great deal depends on the care exercised and the freedom of the surroundings from bacterial germs4 ,under the best conditions wild germs will gradually accumulate in the soured milk1 but their increase may be greatly delayed by attention to the precautions mentioned4 ,the ordinary souring of milk for butter and cheese making is conducted in cool surroundings1 as already stated1 because in such conditions the lactic-acid-producing germs increase relatively faster than the wild germs1 and so gain the upper hand1 but in the case of our special soured milk we kill out1 practically1 all wild bacteria and germs1 and the pure culture having the field to itself1 we can conduct the operation at a higher temperature where the action of the bacteria is at its maximum1 and so obtain the necessary lactification in the minimum of time4 ,the appliances for the souring of milk on the domestic scale require some consideration4 ,we propose to describe the principal forms of apparatus which have been put on the market for the purpose1 and then to give such suggestions as may assist the ingenious in making apparatus for themselves4 ,those who wish for information on the subject of larger apparatus will find it in the following chapter4 ,illustration3 ,,fig4 #da--,photograph of ,agar ,culture1 inoculated with a lactic powder offered to consumers under a fancy name4 ,working on the assumption that the presence of lactic bacteria is inimical to the growth of septic organisms1 this preparation has been placed on the market4 ,the plate shows1 however an abundance of colonies of foreign organisms--sporogenous bacilli1 ,staphylococcus pyogenes albus1 and ,staphylococcus pyogenes aureus4 ,these organisms are shown in the appended photo-micrographs1 and constitute impurities in the preparation4 ,illustration3 ,spore forming bacillus ,illustration3 ,staphylococcus pyogenes albus ,illustration3 ,,fig4 #db--,photograph of ,test ,tubes of ,sterile ,milk1 inoculated with a tablet preparation said to contain pure cultures4 ,the darker liquefied portion of the tube-contents is due to digestion of the curd by proteolytic bacteria1 thus indicating impure culture4 ,pure cultures of lactic acid bacteria coagulate the milk uniformly1 but do not produce any subsequent change in the appearance of the culture1 even after several months4 ,illustration3 ,,fig4 #dc--,photograph of ,test ,tubes of ,sterile ,milk1 each tube having been inoculated with a tablet of a preparation said to contain pure cultures4 ,here1 again1 there is evident peptonisation of the curd1 thus indicating infection by proteolytic ferments4 ,cultures from these tubes demonstrated the presence of a foreign organism4 ,microscopical examination failed to disclose the presence of ,bacillus ,bulgaricus4 ,illustration3 ,,fig4 #dd--,photograph of ,test ,tubes of ,sterile ,milk1 inoculated with a tablet of ,lactobacilline4 ,in contra-distinction to those shown in ,figs4 #db and #dc1 these tubes exhibit homogeneous curdling of the milk without any subsequent digestion or peptonisation of the coagulum4 ,this is indicative of the purity of the culture4 ,the ,society ,le ,ferment of ,paris1 which has been authorised by ,professor ,metchnikoff to prepare and supply to the public his sour milk culture1 provides an apparatus for the treatment of the milk4 ,it is shown in ,fig4 #de1 which consists of a double box having the intervening space packed with a non-conducting material4 ,it is provided with a tight lid4 ,inside1 there is accommodation for two milk vessels1 each with a capacity of about two thirds of a pint4 ,the most difficult thing in the souring of milk is to maintain the temperature as nearly at #ajj ,f4 as possible while the culture is in action4 ,this result is attained by filling the vessel in the middle with boiling water4 ,the insulated walls hinder the escape of heat1 and the quantity of boiling water used is calculated to maintain the temperature steady for the twelve hours of cultivation2 but in cold1 frosty weather it is necessary to refill the central vessel with boiling water in the middle of the period4 ,illustration3 ,,fig4 #de ,the milk jars are washed with hot boiled water and turned upside down to dry4 ,they should not be wiped with a cloth4 ,boil the milk to be treated for ten minutes1 stirring it to promote evaporation1 as it is advantageous to have it in concentrated form4 ,cool rapidly to #ajj ,f4 by placing the boiling vessel in cold water1 add to each bowl one third of a tube of the culture in powder form1 fill up with the boiled and cooled milk1 stir well and cover4 ,place the jars in the box and fill the central vessel with boiling water1 shut the lid tight1 and do not open it 7unless a fresh charge of boiling water is needed7 for ten or twelve hours1 when it will be ready for use4 ,if the liquid culture is used 7one small phial for each bowl7 the milk should be cooled to #hf ,f4 instead of #ajj ,f41 as with the powder4 ,the culture is also supplied in tabloid form4 ,the powder and tabloids keep well1 but the liquid can only be relied on for about two months4 ,the milk prepared as above should be stored in a cool place1 the lids being kept on the bowls4 ,it is good for about two days1 after which it becomes too sour4 ,it can be eaten with sugar1 which not only sweetens it but is beneficial in affording additional suitable food for the acid-producing bacilli4 ,if fresh milk cannot be had1 condensed1 sterilised1 or pasteurised milk may be used1 but1 of course1 fresh milk is best4 ,condensed milk should be diluted with two parts of boiling water and then treated like ordinary milk4 ,an apparatus on similar principles is sold by the ,maya ,bulgare ,company1 ,ltd41 and is illustrated in ,fig4 #df4 ,illustration3 ,,fig4 #df--,soured ,milk ,apparatus of the ,maya ,bulgare ,company1 ,limited1 consisting of an insulated box1 hot-water vessel1 and covered vessels containing the milk and culture4 ,the apparatus consists of cabinet in deal1 ,maya ,bulgare ferment in #bj-;dose bottles1 ,maya ,bulgare ferment in #ajj-;dose bottles1 compressed ,maya ,bulgare tablets in boxes of #h tubes1 ,maya ,bulgare caramels in boxes of #dj1 reduced milk1 china funnels1 and thermometers4 ,the box is insulated1 but the door is on the side1 the hot water vessel is underneath1 and the covered vessels containing the milk and culture are placed on a shelf above4 ,in the front of the illustration are shown the various packages in which the liquid and powder cultures are put up4 ,the procedure is exactly the same as with ,le ,ferment apparatus4 ,lactic ,ferments1 ,limited1 make use of a different principle to maintain the temperature steady during the lactifying period4 ,their apparatus 7,fig4 #dg7 consists of a water vessel mounted on a stand4 ,the milk vessels 7tumblers7 are placed in the water1 and the temperature maintained at the proper figure by a small night light burning underneath4 ,it is recommended that the milk should be placed in an earthenware jar or jug1 which is stood in a pot of water kept boiling for an hour4 ,after cooling add from three to six previously crushed tabloids of culture1 and stir well with a glass rod which has been sterilised in boiling water4 ,the milk is then transferred to three tumblers1 which it should fill1 and these are put into the water vessel1 the water in which should be at about #ajj ,f41 and the night light started4 ,illustration3 ,,fig4 #dg ,messrs4 ,allen ,hanbury1 ,limited1 also make use of the night light to maintain the proper temperature during incubation in their ,sauerin apparatus 7,fig4 #dh74 ,no water1 however1 is placed in the metal container4 ,the procedure is the same as that already described1 and both tablet and liquid pure cultures are supplied4 ,for children it is recommended that the incubation should occupy from three to four hours only1 in other cases eight to ten hours4 ,grated nutmeg1 ground cinnamon1 or other flavouring1 and cream may be used with the soured milk4 ,the night light is also employed in the ,veronelle apparatus of ,messrs4 ,clay1 ,paget and ,company1 ,limited 7,fig4 #di74 ,illustration3 ,,fig4 #dh4--,messrs4 ,allen ,hanbury's ,soured ,milk ,apparatus4 ,they maintain the temperature by means of a night light1 and the culture they use they call ,sauerin4 ,illustration3 ,,fig4 #di4--,vironelle ,apparatus for souring milk1 made by ,messrs4 ,clay1 ,paget ,company1 ,limited4 ,the milk in this case is placed in an earthenware jar1 and is sterilised by placing in a saucepan of water and boiling it4 ,the culture is added after cooling1 the period of incubation being about six hours4 ,the containing vessel is of tin or aluminium1 and has two stands1 the high one for hot and the low one for cold weather1 as in the latter case greater heat is needed to maintain the incubating temperature4 ,the milk is placed in an earthenware jar and is sterilised by placing it in a saucepan of water and boiling it2 continuing the boiling for half an hour4 ,it is allowed to cool to about #ih ,f41 and placed in the incubator1 culture added1 and the lamp lighted1 the cover of the incubator being kept on4 ,the period of incubation is given as six hours4 ,to prepare the next day's supply a tablespoonful of the soured milk is retained and used instead of the culture4 ,this may be continued for fourteen days1 when a fresh start with culture is necessary4 ,the soured milk will keep for thirty-six hours4 ,capacity1 one and one half and two pints2 also a large size for family use4 ,for the preparation of soured milk on a small scale1 one of the various forms of vacuum flasks now on the market may be used with satisfactory results4 ,a little cold water must be poured into the flasks1 and warm water added1 until1 by means of three to four changes1 boiling water can be safely poured in without cracking the flask4 ,this boiling water must be allowed to remain in for about twenty minutes1 and then replaced by freshly boiled milk that has been cooled1 so that its temperature in the flask is about #aje ,f4 ,the culture of lactic organisms should then be added1 the opening of the flask plugged with clean cotton-wool1 and the cap screwed on4 ,in an actual test1 the temperature of the milk placed in such a flask was #aje ,f41 at #g4cj ,p4,m41 and had dropped to #ic ,f4 by #i ,a4,m41 the following day4 ,the milk was curdled1 and possessed the normal acid taste of such cultures4 ,the different types of apparatus are all quite simple1 and it would be easy to make something at home4 ,get two round tins1 the one less in diameter by from two to three inches than the other1 put one or two pieces of wood across the bottom inside the larger tin1 and fill up the space between with cotton-wool1 which is an excellent non-conductor of heat4 ,place the smaller tin centrally inside the larger one4 ,fix three or four distance pieces of wood in the space between them1 fill up with cotton-wool1 leaving a little space at the top to permit the lid of the smaller tin to be fixed on4 ,the boiling-water vessel may be a tin saucepan with a lid1 but no handle1 and its proper place would be on the bottom of the inner tin4 ,a tripod stand made of three pieces of wire bound together1 and with legs reaching past the hot-water vessel to the bottom of the tin1 would support a false bottom of tin forming the shelf on which the vessels of milk to be treated would rest4 ,these might be tumblers covered with tin lids4 ,to prevent radiation through the lid of the inner tin1 a thick pad or hood of cotton-wool packed between cloth would be placed over the top4 ,a little experimenting would be necessary to determine the quantity of boiling water required to maintain the proper temperature4 ,the soured milk obtained in the above manner is of the consistency of ordinary buttermilk2 a separation of whey frequently takes place1 and this may be poured off if desired4 ,the taste and flavour should be pleasantly acid and agreeable1 and both are distinctive enough to give a good idea of the purity of the product4 ,in many places a more concentrated article is made by boiling down the milk to one half or one third of its bulk1 and then fermenting it in the ordinary way4 ,a kind of thick pudding is thus obtained1 which is highly recommended both as an agreeable article of food and as a stronger medium for the support of the germs it is the purpose of the sour milk treatment to introduce into the digestive system4 ,the cultures for making soured milk can now be had from all the leading wholesale and retail chemists1 with directions as to the quantities to be used4 ,it is very necessary that the milk used should be not only fresh and good1 but also free from chemical preservatives4 ,the effect of these is to inhibit the growth and development of bacteria1 and they have therefore an injurious influence on the special lactifying germs it is our object to cultivate4 ,preservatives are now not nearly so much used as they were1 a few years ago1 and there should be no difficulty in obtaining milk free from them4 ,for keeping both fresh and soured milk good a small ice-chest is an excellent device4 ,the germs which are continually dropping into milk kept in open vessels in the air1 even in cleanly surroundings1 are mostly kept out in the close ice-chest1 and the low temperature prevents in a natural way the development of the bacterial germs already in the milk4 ,for the preservation of all kinds of foods the ice-chest is a capital investment1 not to mention the benefit of having cooled drinks1 etc41 as required4 ,they manage things well in this respect in the ,united ,states1 where ice is regarded as a necessity in the summer time by even the poorest people1 and is delivered with the same regularity as the milk4 ,it is necessary to utter a word of warning as to certain forms in which the sour milk bacillus is being offered to the public4 ,it is being compounded with sugar1 chocolate1 and other articles1 and sold in the form of sweets1 etc4 ,there is no reliable proof that these preparations are valuable4 ,certainly1 sugar is a medium in which the lactifying germs can live1 but the quantity so introduced into the system must be very small compared with what is obtained from properly fermented milk4 ,it takes some time1 even with strong cultures1 to fix the acid-producing germs in the large bowel where they are wanted1 and until proper evidence is forthcoming that confectionery preparations are efficacious we would recommend that only the regularly fermented milk be used4 ,it would save trouble1 no doubt1 to treat oneself with a few chocolate creams containing the necessary germs daily1 but if the matter is taken up seriously it will be better to take some pains and stick to methods the efficacy of which has been demonstrated1 leaving the others until their bona fides has been proved4 ,there are always enterprising firms who are prepared to simplify things for us1 but we must make sure that their simplifications are warranted4 ,,chapter ,,vii ,,the ,,preparation ,,of ,,soured ,,milk ,,in ,,the ,,dairy ,there is a tendency in certain medical quarters to discourage the use of soured milk made for profit4 ,this view leaves out of account the fact that besides being of value in medicine1 the article in question is also an excellent food1 which1 as we have seen1 has been consumed by multitudes of people for ages in many parts of the world4 ,there seems also to be satisfactory evidence that a larger percentage than usual of the people who make soured milk a staple of diet attain to a ripe old age4 ,how does it become such a dangerous thing the moment the doctors get it into their hands8 ,of course if a man has an acute disease he places himself entirely in the hands of his medical man1 and eats what is prescribed for him1 or at least he ought to do so1 and if he makes such a submission he is entitled at least to the comfort of being able to feel that his doctor is free from unreasonable prejudices4 ,for the implication that an article made for profit is naturally suspect casts an unwarranted stigma on a large number of honourable people4 ,there are dishonest tradesmen just as there are dishonest and careless doctors1 but to saddle a whole class with the offences of a few would not be a justifiable proceeding in either case4 ,besides1 it is not to the interest of the manufacturing chemist or the dairyman to turn out spurious cultures or bad soured milk1 and on the whole we see no reason why they should not engage in the business4 ,the widespread use of soured milk in other countries as a regular article of diet seems to indicate that all manner of people1 except those suffering from diseases which necessitate medical regulation of diet1 might with probable benefit to themselves add this article to their food list2 and it looks as if a good many of them intend doing so1 even if scandalised doctors threaten to abandon the cure4 ,the dairyman who knows his business does not need to be told of the care which is necessary to keep milk in good condition4 ,the merely commercial consideration of avoiding loss has made him ready to inquire into the best means of prolonging the life of milk as a merchantable article4 ,for a time he relied on chemical preservatives1 but their day is now almost over1 and filtration1 pasteurisation1 and cold storage have taken their place4 ,any one conversant with the trade knows how widely these methods have been adopted of late years2 we may1 therefore1 assume that the average dairyman has at his command milk suitable for the incubation process4 ,the demand for soured milk is not as yet a very large one1 and the apparatus so far developed for its production is meant for the treatment of small quantities4 ,after describing the principal appliances at present in the market we propose to make some suggestions as to the construction of larger apparatus4 ,a firm which has given great attention to the question of maintaining fixed temperatures is that of ,messrs4 ,charles ,hearson ,co41 ,ltd4 ,their incubators for chicken hatching are known all over the world2 and their appliances for biological incubation are very generally used in bacteriological laboratories4 ,with such experience it was natural that they should turn their attention to soured milk apparatus1 and the result is the ,lactobator 7,figs4 #ej and #ea74 ,illustration3 ,,fig4 #ej4--,lactobator made by ,messrs4 ,charles ,hearson ,co41 ,limited1 which is used for the incubation of pure culture in milk in a fairly large way4 ,the illustration shows the ,lactobator closed4 ,illustration3 ,,fig4 #ea4--,messrs4 ,hearson ,company's ,lactobator1 showing the internal arrangements4 ,a copper vessel made to contain water has placed in it a stoneware jar which holds two gallons of milk2 on the top is a lid which carries a thermometer for indicating the temperature of the milk4 ,heat is supplied by a gas ring under the copper vessel2 and in the gas supply is the patent thermostat made use of by ,messrs4 ,hearson also in their biological and poultry incubators1 in which a capsule containing a liquid arranged to boil at a certain predetermined temperature is the regulating factor4 ,when the liquid boils1 the capsule expands1 and by certain mechanical devices regulates the gas supply so as to produce exactly the temperature required4 ,the procedure is as follows3 ,the jar is filled with milk1 and water is run into the copper vessel by the funnel until it runs over at the overflow pipe4 ,the thermostat is lifted off and the full gas supply allowed to pass to the burner1 the temperature of the milk brought up to #ahj ,f4 and maintained for half an hour at this figure4 ,the gas is then turned off1 and cold water run through the funnel until the temperature of the milk registers #ie ,f4 ,the culture is added1 the lid replaced1 and the thermostat put into the pocket at the side of the vessel2 the gas relighted1 and when the temperature reaches #ajj to #ajf ,f4 the capsule of the thermostat will expand and close the gas to a peep1 which is just sufficient to maintain the temperature within the above limits4 ,after eight hours the incubation is completed4 ,edgar's patent apparatus1 the ,lactogenerator1 as provided by the ,dairy ,supply ,co41 ,ltd41 is shown in ,fig4 #eb4 ,illustration3 ,,fig4 #eb4 ,edgar's ,lactogenerator ,the milk is placed in a tinned copper-jacketed vessel and water run in through a vertical pipe until it runs off at the overflow4 ,two gas connections are required with cocks on each1 the one to heat up the milk to the boiling point and maintain it at this for thirty minutes4 ,a skimmer which has been placed in the milk lifts out the coagulated protein and albumen which rise to the top4 ,the cock is then shut and cold water run through the jacket till the thermometer shows #ij ,f41 when the culture is added1 and the other gas supply with the regulator turned on1 and the temperature is automatically maintained at about #ij ,f4 ,time of incubation eight to nine hours4 ,it is recommended to turn cold water into the jacket at the end of the period to prevent overincubation4 ,a somewhat similar apparatus is that of the ,willows ,refrigerating ,co41 ,ltd4 7,fig4 #ec71 with the exception that it has no automatic heat regulator4 ,it is made of tinned steel1 and the operations are the same1 but the sterilising temperature 7obtained by a gas ring or hot plate7 is given as #ahj1 and the incubating temperature #ajj to #ajd ,f4 for a period of twelve hours4 ,presumably this temperature is maintained by a small gas jet or other similar source of heat4 ,the capacity is two gallons4 ,illustration3 ,,fig4 #ec ,apparatus of the ,willows ,refrigerating ,co41 ,ltd4 ,in the apparatus hitherto described the milk is sterilised in bulk1 and is filled into bottles or jars after incubation1 which is not a desirable thing to do1 unless the soured milk is for immediate consumption1 as there is likely to be contamination with injurious germs from the atmosphere4 ,in the domestic apparatus the milk is usually incubated in covered jars in which it can be kept until required for use1 and the practice on the larger scale should be the same4 ,the ,dairy ,outfit ,co41 ,ltd41 have recognised this in their ,lacto apparatus 7,fig4 #ed74 ,illustration3 ,,fig4 #ed ,lacto ,apparatus of the ,dairy ,outfit ,co41 ,ltd4 ,a cylindrical vessel is set loosely on a stand1 beneath which is a lamp calculated to maintain the incubating temperature4 ,the milk is placed in bottles with metal screw tops1 and these are put into the cylindrical vessel2 water is run in round them through the side funnel1 the vessel lifted off the stand1 and heated to sterilising point on a stove4 ,cold water is then run in through the funnel until the temperature is low enough for incubation4 ,culture is added to each bottle and the lids screwed on1 the vessel lifted on to its stand1 and the lamp lighted4 ,the cover of the apparatus has a thermometer fixed on it4 ,on the large scale the treatment of the milk would take place entirely in the jars in which it would be sent out1 and the sterilisation and incubation would be conducted in different pieces of apparatus4 ,the sterilisation would be effected either 7#a7 by direct steaming1 or 7#b7 by hot water heated by steam4 ,fig4 #ee shows the first type of sterilisation4 ,the tank is of wrought iron or steel with strengthening pieces of angle iron4 ,the door1 with pulleys and counterweight for easy handling1 is fastened steam-tight by hinged bolts4 ,the apparatus is mounted on a stand at a convenient height for handling the bottles2 and in front is another stand with channel iron rails to take the waggon in which the bottles or jars to be sterilised are packed4 ,when the door is fast1 steam is turned on1 and regulated to produce the proper temperature by the thermometer fixed in the shell1 in which a pressure gauge is also secured4 ,after sterilising1 the door is opened and the waggon drawn forward to the outside1 allowed to cool1 or removed elsewhere to cool1 and allow space for a new charge4 ,illustration3 ,,fig4 #ee4--,sterilising ,apparatus for sterilising milk on the large scale4 ,the bottles of milk are sterilised1 and the culture can then be added1 and the incubation allowed to proceed in an insulated chamber4 ,the second method of sterilising is by hot water1 as in ,fig4 #ef4 ,the bottles or jars are placed on a perforated false bottom in the rectangular tank1 water run in up to the necks1 and steam turned on2 the lid is fastened with hinged and hooked bolts2 a thermometer fastened in the lid1 and with a long stem enclosed in metal1 indicates the temperature4 ,at the end of the sterilising process cold water is turned on1 and at the same time the overflow water cock is opened2 the cold water gradually reduces the temperature1 and the incubating point is quickly reached4 ,illustration3 ,,fig4 #ef ,another ,method of ,sterilising 7,dairy ,supply ,co41 ,ltd474 ,incubation in bottles or jars1 sterilised in these ways1 can best be conducted in an insulated room1 with say1 six inches of silicate cotton1 granulated cork1 or washed cow hair packed between two-inch by six-inch battens1 covered with matching on either side1 and lined with sheet zinc4 ,it would be an advantage to have an air-lock or anteroom into which the waggons or trays of sterilised jars could be run1 and the door of the anteroom closed before the door of the insulated room is opened4 ,this would tend to prevent variations of temperature in the room1 and also1 by checking free communication with the outside air1 decrease contamination4 ,the waggons of jars would be run in1 and culture added to each jar by a sterilised pipette4 ,the atmosphere of the room would be kept pure by running in air frequently through a filter of moist cotton-wool by means of an electric fan1 and at intervals the interior would be sterilised by the use of formalin vapour4 ,illustration3 ,details of an ,american ,apparatus for ,preparing ,soured ,milk ,,fig4 #eg ,the figures give diagrams ,a1 ,b1 ,c1 and ,d of an apparatus useful for the preparation of lactic foods4 ,the incubating can ,a1 is made of block tin1 and is intended to contain the milk4 ,b1 the warm water container1 should be a stout walled vessel with a circular aperture in the lid1 through which the incubating can may be passed1 and clamped down as in ,c4 ,b is fitted with three stout iron legs1 which should be sufficiently long to allow of a small lamp or gas-jet being placed beneath the container to maintain a uniform temperature4 ,d gives an external view of the apparatus4 ,for the preparation of soured milk1 separated milk is placed in the incubating can1 and heated up to #ajj ,c4 7#bab ,f47 for thirty minutes4 ,it is then allowed to cool to room temperature1 and the culture1 or tablet containing the lactic acid bacteria1 is then added1 and thoroughly stirred for a minute or so4 ,the can is then immersed in the warm water container and kept at a temperature of #hf ,f4 to #ajd ,f41 according to the organisms used1 for ten to twelve hours4 ,by the end of this time the milk ought to be converted to a jelly-like mass1 and after being stirred vigorously for a short time1 may be cooled on ice1 and is then ready for consumption4 ,the incubating temperature could very conveniently be maintained by an electric radiator1 and as the insulation would largely prevent leakage1 the amount of electric current used would not be large4 ,the regulating apparatus might consist of a thermometer with platinum wires fused through the stem at the proper temperature1 say #ajj ,f4 ,when the mercury rises to this figure it will complete the circuit of a battery which will actuate certain well-known devices for turning off the current which actuates the radiator4 ,in this way a very fine automatic arrangement would be achieved4 ,steam pipes might be used instead of the radiator1 and the thermometer above described could be used in this case also1 with appliances to cut off the steam4 ,on the large scale1 labour-saving appliances1 such as the mechanical brush jar and bottle washer1 and the automatic filler for jars or bottles1 would be employed1 and an overhead trackway for carrying the trays of jars from the steriliser to the incubator would be a great convenience4 ,a further adjunct of considerable importance would be a cold room1 worked either by ice or a refrigerating machine1 in which the jars could be stored after incubation1 so as to arrest the process of lactification1 and maintain the soured milk in good condition until required for use4 ,,chapter ,,viii ,,soured ,,milk ,,in ,,health ,,and ,,disease ,when people are ill the best thing they can do is to place themselves in the hands of the doctor1 who will try to regulate their lives1 including their diet1 in accordance with the conditions which science suggests as the most likely to lead to their recovery4 ,it is not the aim of this book to teach persons who should be under medical treatment to doctor themselves2 soured milk may or may not be beneficial in their case--that is for the medical man to say2 and further1 if it should be beneficial the doctor ought to have its preparation under his control4 ,slight differences in quality and purity may count for much in cases of acute disease1 differences which might not matter to the person who requires no medical attention1 and who consumes the article as a health-giving food4 ,a considerable body of evidence is already on record as to the potency in certain cases of soured milk as a curative agent1 and it seems to have taken its place in medicine as a recognised remedy4 ,there is a wide field of usefulness1 however1 outside of the strictly medical one4 ,professor ,metchnikoff has collected many striking examples of individuals and peoples inhabiting different parts of the world1 who thrive1 and in many cases attain to a great age1 and whose diet consists largely of soured milk4 ,he has made a wide and general inquiry into the causes which tend to shorten life1 and makes out a strong case in support of the view that in many cases this is the result of what is called auto-intoxication or self-poisoning4 ,in man and in the mammalia generally1 the colon or large intestine is very largely developed2 this organ is not of much value in the digestion of food1 and seems to be chiefly a receptacle for waste material2 it is1 as a rule1 extremely rich in bacterial flora1 which produce putrefactive changes in the waste material4 ,as a result various poisonous principles are evolved1 and these find their way into the blood1 accompanied frequently1 there is every reason to believe1 by the injurious bacteria themselves4 ,in this way many diseases and ailments are produced which shorten life4 ,the inquiry then naturally turns to what is the best way of dealing with this state of matters4 ,it is known that the bacteria referred to flourish best in alkaline or at least non-acid surroundings1 and it is known that these conditions very frequently exist in the large intestine4 ,acids are the best antiseptics2 they have been used from time immemorial as preservatives2 pickles are preserved in vinegar or acetic acid1 and when milk is allowed to sour under proper conditions1 the germs of putrefaction are destroyed or their activity inhibited1 and it keeps a considerable time4 ,doubtless1 in hot countries1 it was this property of lactic acid which first led to milk being artificially soured with a view to its preservation as an article of food4 ,so powerful is lactic acid in this respect that it is a custom in some countries to preserve meat by placing it in soured milk4 ,how can acids be applied so as to control the bacterial flora of the large intestine8 ,not in the ordinary way1 because1 when administered through the mouth1 they are used up long before they can penetrate to the colon4 ,the brilliant idea occurred to ,professor ,metchnikoff1 of administering acid-producing germs which might work their way through the digestive system1 and1 reaching the large intestine1 produce the acid required4 ,after much experimenting the bacillus of ,massol1 ,bacillus bulgaricus1 was adopted as the most suitable4 ,the ,bulgarian bacillus is an extremely vigorous one1 multiplying with great rapidity1 and persisting in conditions that would be inimical to other microbes4 ,the growth and development of bacteria is interfered with by the products of their own activity2 thus1 ordinary lactic-acid-producing organisms die when a certain amount of lactic acid has been developed2 the same fate overtakes the ,bulgarian bacillus1 but it survives longer and is able to produce as much as two and one half per cent4 of lactic acid in milk before it ceases operations4 ,it seemed therefore the most likely to be able to survive the journey through the digestive system4 ,experiments fully bore out this supposition1 as no great difficulty was encountered in naturalising the ,bulgarian bacillus in the large intestine1 not only in milk cultures1 but grown in solution of malt1 bouillon1 etc4 ,it thrives in all kinds of sugar1 and therefore can be administered in a variety of media1 very beneficial results following in many cases4 ,direct tests showed a large reduction of the injurious intestinal flora when the ,bulgarian bacillus had been naturalised in the colon1 and the bacillus persisted long after it had ceased to be administered4 ,specialists who have taken up the subject report the cure of many ailments through the agency of soured milk1 and it seems to have entered upon a lengthening career of medical usefulness4 ,the fact of so many old people being found in countries where soured milk is a staple of diet naturally raises the question as to whether its general use in other countries might not have a beneficial effect on health and longevity4 ,its usefulness as a remedial agent in certain diseases is already demonstrated2 is there not a strong probability1 amounting almost to a certainty1 that its consumption by people in health would tend to ward off many ailments and prolong life8 ,of course there will be some for whom it is not suitable2 there are people who cannot eat strawberries without discomfort1 but no one thinks of prohibiting the general use of the fruit on that account4 ,in the matter of diet the person in health1 if he exercises ordinary care1 may be left to find out for himself what suits him4 ,the soured milk remedy is not a disagreeable one1 as1 when properly prepared1 the article forms both a pleasant and refreshing article of diet4 ,the question of getting the right article1 however1 is a very important one4 ,milk is a splendid rearing ground for many bacteria1 some of which are very injurious2 among these may be pathological germs1 the seeds of tuberculosis1 enteritis1 etc4 ,the danger with soured milk is1 that in the process of culture we develop the best condition for the increase of these when they preponderate1 or when1 through the use of bad cultures1 the lactic-acid-producing bacteria are absent1 or present only in small numbers4 ,by the thorough boiling of the milk1 we get rid of all living bacteria and nearly all spores or germs1 and by scrupulous cleanliness in the vessels used--scalding or even boiling them1 and allowing them to dry naturally in an inverted position--we greatly diminish the probability of infection with fresh injurious germs from the atmosphere4 ,all depends on the purity of the culture employed2 this can now be obtained1 prepared in the most careful manner1 from wholesale chemists making a speciality of its manufacture4 ,as we have seen1 even the ,bulgarian bacillus is ultimately killed by the products of its own activity1 and the natural corollary is1 that the life of cultures cannot be a long one4 ,only those cultures should be bought which are labelled with the date to which they are guaranteed to maintain their efficiency4 ,with fresh good milk1 careful boiling1 scalding1 and cleanliness with regard to the containing vessels1 and the means of maintaining the incubating temperature for ten or twelve hours1 there is not the slightest difficulty in preparing perfectly reliable soured milk4 ,there are simple tests which will sufficiently guide the experimenter2 the soured milk should not be too acid to the taste1 and it has a flavour of its own by which its quality can be recognised4 ,the litmus test-papers mentioned in the chapter on the chemistry of milk are very useful2 both the red and the blue papers should be obtained and used first of all in testing the quality of the fresh milk4 ,after incubation the soured milk should turn the blue paper decidedly red2 if this does not occur1 test it with the red paper2 if the latter turns blue it is proof that the wrong fermentation has taken place--that putrefactive germs have gained the upper hand4 ,the most probable explanation is1 that the culture is bad1 the ,bulgarian bacillus is not present1 or if so1 only in small numbers4 ,with these simple tests1 combined with proper care1 one cannot go far wrong4 ,the ,eastern nations who prepare soured milk in various forms do not exercise the care we have predicated1 but they seem to make the article of fairly constant and good quality4 ,it has been suggested in explanation that1 as the ordinary flora differs in different countries1 the bacterial flora varies in a similar manner1 and that in these ,eastern countries injurious bacteria are not so prevalent in the atmosphere as they are with us4 ,it is also said that the flavour of the soured milk prepared in ,bulgaria is quite different from that prepared in ,paris1 ,london1 or ,new ,york2 one reason probably is that the maya or ferment used in ,bulgaria contains several other organisms besides the ,bulgarian bacillus1 which raises the question whether a pure culture of one bacillus is the best to use4 ,professor ,metchnikoff found that this bacillus alone had certain defects2 it attacks fat and is apt to give a tallowy taste when cream is present in the milk4 ,he therefore associated with it another lactic-acid-producing organism1 and this combination is the basis of his culture called lactobacilline4 ,the presence of yeasts1 which occur in the ,eastern ferments1 has been advocated by some2 the yeast in association with the lactic organisms produces a small amount of alcohol4 ,the question of the composition of the culture will have to be fought out by the experts1 but meantime1 if we go to the right source1 we have good enough cultures to go on with4 ,a good deal can be said for the use of skimmed or separated milk instead of whole milk4 ,cream as a rule contains far more bacteria than the rest of the milk1 and we therefore start from a surer foundation when it is removed2 besides1 the mechanical separator1 now so largely used1 removes slime and other impurities from the milk1 and these also are hotbeds of bacteria4 ,soured milk may be taken at any time1 the first thing in the morning1 before or after meals1 or the last thing at night4 ,the quantity will vary with the individual1 but from half a pint to a pint is a fair amount for daily use4 ,if one wishes to have the maximum effect it is necessary for the time being to curtail the use of butcher's meat and substitute fish1 yolk of eggs1 and other similar foods2 not much alcohol should be taken1 and smoking might be reduced to a minimum4 ,those who cannot take even skimmed milk may use whey in which to cultivate the bacillus2 it is not desirable to employ the whey which has been separated by the use of rennet1 as in cheese- or junket-making4 ,a better article is obtained by adding a very small quantity of pure hydrochloric acid to milk which has been boiled1 and then filtering through a sieve1 which retains the curd while the liquid whey passes through2 a pinch of soda is added to neutralise the excess of acid1 and1 after boiling1 the liquid should turn red litmus paper blue2 it is then ready for the addition of the culture and incubation in the same manner as with milk4 ,a solution of malt--the extract dissolved in hot water is convenient--may also be used instead of milk1 and strongly malted bread or biscuits are excellent to take with the soured milk or cultures in other mediums1 to supply food for the bacillus in the form of malt sugar4 ,other sugars1 cane or grape1 are also very useful1 and may be taken in the form of fruit juices1 syrups1 confections1 jams1 sweet puddings1 etc4 ,we lay stress on the use of soured milk or other cultures of the ,bulgarian bacillus by people in health as a probable preventive of disease and a possible agent in the lengthening of life1 but it may be of interest to give a short account of its use by medical men in the treatment of various ailments4 ,an ,english authority on the subject1 ,dr4 ,herschell1 states that the symptoms of the poisoning of the system by the toxic substances produced by injurious bacteria in the large intestine may include headaches1 misery and depression of spirits1 drowsiness and stupor1 giddiness1 dimness of sight and dizziness1 fatigue without obvious cause1 both of the muscles and brain1 fear1 panic1 and nervousness1 disagreeable sensations in the limbs or face1 such as numbness1 tingling1 or prickling1 crawling sensation of weight or of heat or cold1 dyspepsia of the sort where there is a deficiency of hydrochloric acid and pepsin in the gastric juice1 accompanied by flabbiness and loss of power in the muscles of the stomach1 and characterised by flatulence1 nausea1 loss of appetite1 with discomfort and weight after food1 furred tongue1 emaciation1 earthy colour of the skin1 offensive perspiration and the other signs of biliousness1 enlargement of the liver1 and anmia4 ,these symptoms may have other causes1 and when one or several of them are present a chemical and physical examination of the urine and fces is necessary to prove that they have resulted from auto-intoxication4 ,when this is shown the soured milk treatment is indicated1 and many striking cures are detailed as witnesses to its efficacy4 ,the liver and kidneys are the natural guardians of the body against the toxines we are speaking of1 and frequently they are over-strained2 the soured milk treatment greatly lightens their load4 ,in malignant disease of the stomach1 soured milk will frequently be retained when all other foods are rejected4 ,in cases of neurasthenia and gout it has also proved of value1 and in the run-down condition which is so common in middle life4 ,chronic diarrhoea and certain forms of constipation have in numerous instances yielded to the treatment1 the whey culture being usually found the most suitable4 ,then1 in some forms of anmia1 the lactic acid cultures have proved most successful1 and1 as a means of rendering the gastro-intestinal track aseptic previous to operations1 they have proved of considerable value4 ,if all this has been accomplished in a year or two1 what may not we look forward to in the future when more extended use and experiment shall have more fully exhausted the possibilities of the cure8 ,but if we follow the example of the different nations who have so long used soured milk as a regular article of diet1 does it not seem probable that we may eliminate some1 at least1 of the causes of ill-health that call for the intervention of the doctor8 ,the human organism is by no means perfect2 we have within us many defective parts1 and some organs whose working seems to be against the welfare of the economy4 ,it has now been clearly shown that one of the chief of these is the large intestine1 as to the use of which only vague and unsatisfactory theories have been formed4 ,there can be no doubt as to the damage which it frequently inflicts on the system1 and1 thanks to the researches of ,professor ,metchnikoff and other investigators1 we seem to be in possession of a natural remedy which is sufficient to deal with the evils it produces4 ,,footnotes3 #a ,discoveries in ,nineveh and ,babylon1 by ,layard1 chap4 xiii4 #b ,ex4 xviii4 and xxiii42 ,lev4 ii4 and xi4 #c ,encyclo4 ,biblica4 #d ,burckhardt and ,doughty4 #e ,annals of ,dairying in ,europe1 by ,loudon ,m4 ,douglas4 #f ,burckhardt1 ,bedouins4 #g ,this word is spelt in a great many ways by different writers3 ,yoghourt would seem to be the one most favoured4--,,author4 #h ,damascus and ,palmyra1 by ,chas4 ,g4 ,addison1 #ahch4 #i ,travels in ,syria and the ,holy ,land1 by ,burckhardt1 #ahbb4 #aj ,lands of the ,saracens1 by ,b4 ,taylor4 #aa ,travels through ,sweden1 ,finland1 and ,lapland and to the ,north ,cape in the years #agih and #agii1 by ,joseph ,acerbi1 #ahjb4 #ab ,letter to the author1 from ,mr4 ,h4 ,cavendish ,venables1 ,british ,vice-,consul at ,varna4 #ac ,one ,hundred and ,twenty ,years of ,life1 by ,reinhardt2 ,the ,secret of ,longevity1 by an ,f4,r4,m4,s4 #ad ,foods1 their ,composition and ,analysis1 by ,a4 ,w4 ,blyth4 #ae ,dictionary of ,applied ,chemistry1 by ,t4 ,e4 ,thorpe1 ,c4,b4 #af ,koumiss or ,fermented ,mares' ,milk and its ,uses1 and the ,treatment and ,cure of ,pulmonary ,consumption and ,other ,diseases1 by ,l4 ,carrick1 ,m4,d41 #ahha4 #ag ,transactions of the ,royal ,society of ,edinburgh1 vol4 i4 #ah ,clarke's ,travels1 #ahaj4 #ai #ahde4 #bj ,dictionary of ,applied ,chemistry1 by ,thorpe4 #ba ,a leathern bottle4 #bb ,i have brought forward ,tchembulatof's receipt1 which differs from ,bogoyavlensky's in the use of a larger quantity of millet-flour1 and in the boiling of the latter apart from the milk4 ,dr4 ,postnikof's plan is the following3 ,half a pound of millet-flour and a quarter of a pound of malt are mixed with a sufficient quantity of honey to form a paste1 which is put into a clean jar1 covered with a linen cloth1 and placed on a warm stove4 ,the mass soon begins to rise1 and is then taken out1 wrapped in a piece of muslin1 and dropped into a clean earthenware vessel1 containing about a quart of new mares' milk1 which is placed in the same temperature that the paste was kept in4 ,as soon as signs of fermentation begin to show themselves in the fluid1 the paste must be removed1 while the milk1 after being stirred1 should be left in the same temperature till bubbles appear 7only in very small quantities7 on its surface4 ,the ferment is then ready4 #bc ,food and the ,principles of ,dietetics4 #bd ,food and the ,principles of ,dietetics1 by ,robert ,hutchison1 ,m4,d4 #be ,bacteria in ,milk and its ,products1 by ,conn4 #bf ,dict4 ,app4 ,chem41 ,thorpe4 #bg ,nature1 ,july #bc1 #ahhd4 #bh ,the ,exploration of the ,caucasus1 by ,duncan ,w4 ,freshfield1 #ahif4 #bi ,quoted by ,george ,m4 ,sternberg1 ,m4,d41 ,,ll4,d41 ,text-,book of ,bacteriology1 #ahih4 #cj ,encyclo4 ,biblica4 #ca ,conn4 #cb ,cyclo4 of ,biblical ,lit41 ,m',clintock and ,strong1 and ,burckhardt's ,arabia4 #cc ,the ,indian ,medical ,gazette1 ,sept41 #aiji1 ,a ,new ,lactic ,acid producing ,streptothrix1 by ,gopal ,ch4 ,chatterjee1 ,m4,b4 #cd ,in their studies on ,leben in the ,annales de l',institut ,pasteur of #ahii1 ,rist and ,khoury1 in speaking of the amount of lactic acid produced by ,streptobacillus lebenis in milk1 say ,nous avons mesur cette acidit dans une culture sur petit lait de vingt-quatre heures2 elle tait 4#bfa grms4 per cent4 exprime en acide lactique1 which will make the amount of lactic acid produced in one litre of milk #b4fa grms4 ,the production of this small amount of lactic acid does not tally with the ordinary view of the vigorous lactic-acid-producing power of the bacillus4 #ce ,prolongation of ,life4 #cf ,prolongation of ,life4 #cg ,an accurate census of ,bulgaria is being prepared and will exhibit the cases of long life in that country4 #ch ,see ,a4 ,rosam1 sterreichische ,molkerei ,zeitung1 #ae1 p4 #ca4 #ci ,revue gnrale du ,lait1 vii41 pp4 #h and #i 7letter from ,dr4 ,otakar ,laxa of ,prague1 ,bohemia1 to the author74 #dj ,on the ,prolongation of ,human ,life1 by lie ,metchnikoff2 also ,the ,century ,magazine1 ,nov41 #aiji1 ,the ,utility of ,lactic ,microbes1 by the same author4 #da ,century ,magazine1 ,nov41 #aiji4 #db ,see ,annals of ,dairying in ,europe1 by ,loudon ,m4 ,douglas4 #dc ,adapted from a report by ,robert ,e4 ,turnbull1 in ,live ,stock ,journal4 #dd ,facts about ,milk1 by ,r4 ,a4 ,pearson1 ,b4,s41 ,washington4 #de ,care and ,handling of ,milk1 ,marshall and ,wright1 ,bulletin #bba1 ,michigan1 #aijd4 #df ,journal of the ,royal ,society of ,arts1 ,march #f1 #aijh--,modern ,dairy ,practice1 by ,loudon ,m4 ,douglas4 #dg ,skolotowski1 ,wratsch1 #ahhc 7,russian71 from ,codwyssozki4 #dh ,podowyssozki1 ,zeitschr4 f4 diat4 u4 physik4 ,therapie vol4 v41 #aija1 p4 #egj4 #di ,hammersten1 ,jahresb4 u4 d4 ,fortsch4 d4 ,tierchem1 #ahhf1 ,bd4 #af1 p4 #afc4 #ej ,essaulow1 ,dissert4 ,moscow1 #ahie1 ,abstr41 ,koch's ,jahresb41 #ahie1 ,bd4 #f1 p4 #bbb4 #ea ,kern1 ,bulletin ,soc4 des ,naturalistes de ,moscow1 #ahha1 #c1 p4 #ada4 #eb ,krannhals1 ,deutsch4 ,arch4 f4 ,klin4 ,med41 #ahhd1 ,bd4 #ce1 p4 #ah4 #ec ,beijerinck1 ,centralbl4 ,bakt4 ,par41 #ahhi1 ,bd4 #f1 p4 #dd4 #ed ,scholl1 ,die ,milch1 ,wiesbaden1 #ahia1 p4 #ch4 #ee ,adametz1 ,centralbl4 ,bakt4 ,par41 #ahhi1 ,bd4 #e1 p4 #aaf4 #ef ,freudenreich1 ,landw4 ,jahrb4 d4 ,schweiz41 #ahif1 vol4 x41 p4 #a4 #eg ,nikolaiewa1 ,annals of the ,botan4 ,lab4 of the ,med4 ,inst4 for ,women1 ,no4 #aj4 ,st4 ,petersburg1 #aijg4 #eh ,kuntze1 ,centralbl4 ,bakt4 ,par41 #aiji1 #bd1 p4 #aja4 #ei ,see ,chap4 ,,ii4 #fj ,rubinsky1 ,centralbl4 ,bakt4 ,par4 ,,ii41 #aiaj1 vol4 xxviii41 p4 #afa4 #fa ,biel1 ,jahresb4 4 d4 ,fortschr4 d4 ,tierchem1 #ahhf1 #af1 p4 #aei4 #fb ,allik1 ,dissertat4 ,dorpat41 #ahif1 #ai1 p4 #cjc4 #fc ,fleischmann1 ,lehrb4 d4 ,milchwirtschaft1 #b;d edition4 ,bremen1 #ahih4 #fd ,rist and ,khoury1 ,annal4 ,pasteur1 #aijb1 #af1 p4 #fe4 #fe ,guerbet1 ,comptes ,rendus1 #aijf4 #ff ,weigmann1 ,lafar's ,handb4 d4 ,techn4 ,mykol41 #b;d edit41 #aije1 vol4 ii41 p4 #acd4 #fg ,emmerling1 ,cent4 ,bakt4 ,par4 #ahih1 vol4 iv41 p4 #dah4 #fh ,lindner1 ,mikroscop4 ,betriebscontrolle1 i4 d4 ,grungsgew1 #c;d edit41 ,berlin1 #aija4 #fi ,kalantharianz1 ,dissert4 ,berlin1 ,abs4 in ,koch's ,jahresb41 #ahih1 ,bd4 #i4 #gj ,luerssen and ,khn1 ,centralbl4 ,bakt4 #ga ,piorkowski1 ,sitzungsber4 der ,berl4 med4 ,ges41 ,nov41 #aijg4 #gb ,metchnikoff1 ,the ,prolongation of ,life4 #gc ,grigoroff1 ,revue ,mdicale de la ,suisse ,romande1 #aije1 p4 #aj4 #gd ,grixoni1 ,abstr4 ,cent4 ,bakt4 ,par4 #aa1 #ae1 p4 #gej4 #ge ,freudenreich and ,jensen1 ,cent4 ,bakt4 ,par4 #aa1 #ahig1 #c1 #ede4 #gf ,moro1 ,wien4 klin4 ,wochenschr41 #e1 #aijj4 #gg ,makrinoff1 ,cent4 ,bakt4 ,par4 #aa1 #aiaj1 vol4 xxvi41 p4 #cgd4 #gh ,white and ,avery1 ,cent4 ,bakt4 ,par4 ,,ii1 #aiji1 vol4 xxv41 p4 #afa4 #gi ,hastings and ,hammer1 ,research ,bull41 ,wisconsin ,experimental ,station1 #f1 #aiji4 #hj ,boutroux1 ,comp4 ,rend41 #hf1 #aije1 #fje4 #ha ,richet1 ,comp4 ,rend41 #hf1 #aije1 #eej4 #hb ,koning1 ,milchw4 ,zentralbl41 #aije1 #a1 #bhj4 #hc ,heinemann1 ,centralbl4 ,bakt4 ,par4 #aijh1 #ba1 #eg4 #hd ,chap4 ,i4 #he ,metchnikoff1 ,the ,prolongation of ,life1 #aijh1 p4 #afa4 ,,index ,a ,acerbi1 #h ,acidity of milk1 #fd ,adametz on keffir1 #ib ,albumen1 #eb ,alcoholic fermentation1 #ag1 #hd ,allen ,hanbury's apparatus1 #acb ,american incubating apparatus1 #adi ,analysis of milk1 #dh1 #fa ,aneyza ,bedouins1 #b ,arabs1 #b ,arak1 #ajf ,ash of milk1 #ef ,b ,bacillus acidi lactici1 #ajg1 #aab ,bacillus acidophilus1 #aaj1 #aab ,bacillus bulgaricus1 #ci1 #df1 #hb1 #ajh1 #aaj1 #abc1 #aed ,bacillus casei1 #aac ,bacillus caucasicus1 #ib1 #id1 #ie1 #aai ,bacillus caucasina1 #ci ,bacillus coli1 #de ,bacillus esterificans1 #if ,bacillus keffir1 #if1 #ig ,bacillus lebenis1 #aje ,bacillus matzoon1 #aji1 #aaj ,bacillus of long life1 #df ,bacillus putrificus1 #abb ,bacillus subtilis1 #ij1 #ib1 #ajg ,bacteria in milk1 #gf ,bacteriology of fermented milks1 #hd ,bacterium acidi lactici1 #ib1 #if ,bacterium arogenes1 #ib1 #if ,bacterium coli commune1 #aai1 #abb ,bacterium sardous1 #aaj1 #aaa ,balkan ,peninsula1 #d ,bedouins1 #b ,beijerinck on keffir1 #ia ,biestings1 #fc ,biology of the keffir grain1 #ij ,blood1 water contents of1 #ej ,bourgoul1 #f ,bulgarian maya1 #aj1 #aji ,bulgaricus group1 cultural characteristics of1 #aae ,burckhardt1 #f ,butin1 #ea ,butyric acid fermentation1 #af ,butyrin1 #ea ,c ,camels' milk1 #b ,caprinin1 #ea ,capronin1 #ea ,caprylin1 #ea ,carrick on koumiss1 #ah ,casein1 #eb1 #ec ,centenarians in ,servia1 ,bulgaria1 and ,roumania1 #da ,chatterjee on ,dadhi1 #ch ,chemistry of milk1 #dg ,chocolate preparations and the soured-milk bacillus1 #acg ,citrates in milk1 #eg ,clay1 ,paget ,company's apparatus1 #acb ,coagulation of casein1 #ei ,colitis1 #de ,colostrum1 #fc ,constituents of milk1 #dh ,continuous apparatus for producing soured milk1 #ha ,creamometer1 #fb ,d ,dadhi1 #ae1 #ch ,dairy ,machinery ,construction ,company's apparatus1 #hj1 #hb ,dairy ,outfit ,company's apparatus1 #ade ,dairy ,supply ,company's apparatus1 #adc2 steriliser1 #adh ,dirt in milk1 #fc ,diseases of keffir grains1 #ig ,dispora caucasia1 #cd1 #ij ,dried sour milk1 #e ,duclaux1 #ea ,e ,edgar's ,lactogenerator1 #adc ,eggs1 yolk of1 #eb ,enteritis1 #de ,enzymes in milk1 #eg ,equipment for town's dairy1 #hj ,essaulow on keffir1 #hi1 #ib ,f ,fat of milk1 #ej ,ferments at the altar1 #c ,flgge1 #ce ,freshfield on keffir1 #cc ,freudenreich1 #ib ,g ,gaseous fermentation1 #hd ,gay-,lussac1 #ag ,gioddu1 #ajg ,globulin1 #ed ,grieve1 ,dr4 ,john1 on koumiss1 #ai ,h ,hammerstein on keffir1 #hi ,handling of milk1 #fh ,health and disease1 #aea ,hearson ,company's ,lactobator1 #ada ,hebrews1 #c ,houran1 inhabitants of1 #f ,hueppe1 #af ,hutchinson1 ,dr4 ,h4 ,b41 bacillus from ,english market milk1 #abj ,hutchison on koumiss1 #cj ,i ,ice chest1 #acf ,impure cultures1 #aeh ,incubators1 #ada ,india1 #a ,international ,dairy ,federation1 #fh ,j ,jebours1 #c ,k ,kalmucks1 #bj ,keffir1 #ae1 #cb1 #he2 old1 #hh ,keffir grain1 biology of1 #ij ,kephir1 #cd1 #he4 ,see also ,keffir4 ,keshk1 #f ,keshk-leben1 #f ,koumiss1 #ae1 #ah2 ,bogoyavlensky's method of preparation1 #bh1 #ih2 analysis1 #ajb2 artificial1 #ajb ,krannhals on keffir1 #ia ,kuntze1 #ie ,l ,lactic acid1 bacillus1 #af2 cultures1 #ee2 fermentation1 #af1 #hd2 ,ferments apparatus1 #aca ,lacto apparatus1 #ade ,lactobacilline1 #aeh ,lactobac4 caucasicus1 #ia ,lactobacillus keffir1 #id ,lactometer1 #fd ,lapland1 #h ,laurin1 #ea ,layard1 #b ,leben1 #ae1 #cg1 #ajd ,leben ,rab1 #ajd ,lecithin1 #eb ,le ,ferment apparatus1 #abh ,liebig1 #ag ,longevity1 #aee ,m ,mares' milk1 #bd ,matzoon1 #ae1 #ch1 #ajf ,maya1 #db2 ,bulgarian1 #aj ,maya ,bulgare ,company's apparatus1 #aca ,meeresy1 #e ,metchnikoff1 #cd1 #dj1 #dd1 #aba1 #aeh1 #afc ,micro-organisms1 discovery of1 #ac ,middle ,ages1 #ac ,milk-filling apparatus for bottles1 #hb ,milk1 general properties of1 #eg2 of different animals1 #fj2 supply of the ,united ,kingdom1 #fi2 industry in the ,united ,states1 #ga2 management1 #gd ,mitscherlich1 #ag ,myristin1 #ea ,n ,neolithic times1 #a ,nikolaiewa1 #ie ,nitrogenous constituents of milk1 #eb ,o ,ojrn1 #ajf ,olein1 #ea ,oxygala of ,pliny1 #d ,p ,paleolithic times1 #a ,palmitin1 #ea ,pasteur1 #ad1 #gh ,pasteurisation1 #gh ,pelouze1 #ag ,pilaff of rice1 #e ,pina1 #ba ,podowyssowski on keffir1 #hg ,preparation1 of soured milk1 #ha2 in the house1 #abe2 in the dairy1 #aci ,primary cooler1 #gh ,proteids1 #ec ,pyrenees1 #d ,r ,reindeer's milk as soured milk1 #h ,rubruquis1 ,william de1 #ai ,s ,saccharomyces cerevisse1 #ij ,saccharomyces keffir1 #cb1 #cc1 #ia1 #ic1 #id ,sakwaska1 #hh ,sale of ,food and ,drugs ,act1 #ahii1 #di ,scheele1 #ag ,scholl on keffir1 #ia ,scythians1 #ah ,secondary cooler1 #gi ,shammar ,bedouins1 #b ,sheneena1 #b ,skolotowski on keffir1 #hf ,smith1 ,professor ,robertson1 #c ,soured milk1 in the house1 #abe2 in the dairy1 #aci2 in health and disease1 #aea2 from impure cultures1 #aeh2 use of1 #aei ,souring of milk1 #dg1 #ed ,specific gravity of milk1 #fe ,stearin1 #ea ,steriliser1 #adh ,streptobacilli lebeni1 #ci ,streptobacillus lebenis1 #aaa ,streptococcus a1 #ic1 #id ,streptococcus acidi lactici1 #ie1 #if ,streptococcus b1 #ic1 #id ,streptococcus lacticus1 #ib1 #ic1 #abb1 #abd ,sugar of milk1 #ed ,sugar preparations and the soured-milk bacillus1 #acg ,suter-,naef on ,swiss koumiss1 #bf ,swedish whey cheese1 #fj ,swiss hard cheese1 #aac ,symptoms of disease1 #afa ,t ,temperature allowances when testing milk1 tables of1 #ff ,town's dairy equipment1 #hj ,transmission of disease by milk1 #gb ,u ,united ,kingdom1 milk supply of1 #fi ,united ,states1 milk industry of1 #ga ,urgoutnik1 #dc ,v ,van ,leeuwenhoek1 #ac ,variation limits of milk1 #di ,vedas1 #a ,veronelle apparatus1 #acb ,vina1 #ba ,vinous fermentation1 #ag ,w ,willows ,refrigerating ,company's apparatus1 #add1 #ade ,wilson on koumiss1 #bc ,y ,yoghourt1 #i1 #db1 #df1 #ajg ,yoghourt bacillus1 #aji ,z ,zakvaska1 #db 99 99 99 99 99 ,putnam's ,science ,series #a4 ,the ,study of ,man4 ,by ,a4 ,c4 ,,haddon4 #b4 ,the ,groundwork of ,science4 ,by ,,st4 ,,george ,,mivart4 #c4 ,rivers of ,north ,america4 ,by ,,israel ,c4 ,,russell4 #d4 ,earth ,sculpture1 or2 ,the ,origin of ,land ,forms4 ,by ,,james ,,geikie4 #e4 ,volcanoes2 ,their ,structure and ,significance4 ,by ,t4 ,g4 ,,bonney4 #f4 ,bacteria4 ,by ,,george ,,newman4 #g4 ,a ,book of ,whales4 ,by ,f4 ,e4 ,,beddard4 #h4 ,comparative ,physiology of the ,brain1 etc4 ,by ,,jacques ,,loeb4 #i4 ,the ,stars4 ,by ,,simon ,,newcomb4 #aj4 ,the ,basis of ,social ,relations4 ,by ,,daniel ,g4 ,,brinton4 #aa4 ,experiments on ,animals4 ,by ,,stephen ,,paget4 #ab4 ,infection and ,immunity4 ,by ,,george ,m4 ,,sternberg4 #ac4 ,fatigue4 ,by ,a4 ,,mosso4 #ad4 ,earthquakes4 ,by ,,clarence ,e4 ,,dutton4 #ae4 ,the ,nature of ,man4 ,by ,,lie ,,metchnikoff4 #af4 ,nervous and ,mental ,hygiene in ,health and ,disease4 ,by ,,august ,,forel4 #ag4 ,the ,prolongation of ,life4 ,by ,,lie ,,metchnikoff4 #ah4 ,the ,solar ,system4 ,by ,,charles ,,lane ,,poor4 #ai4 ,heredity4 ,by ,j4 ,,arthur ,,thompson1 ,m4,a4 #bj4 ,climate4 ,by ,,robert ,,decourcy ,,ward4 #ba4 ,age1 ,growth1 and ,death4 ,by ,,charles ,s4 ,,minot4 #bb4 ,the ,interpretation of ,nature4 ,by ,c4 ,,lloyd ,,morgan4 #bc4 ,mosquito ,life4 ,by ,,evelyn ,,groesbeeck ,,mitchell4 #bd4 ,thinking1 ,feeling1 ,doing4 ,by ,e4 ,w4 ,,scripture4 #be4 ,the ,world's ,gold4 ,by ,l4 ,,de ,,launay4 #bf4 ,the ,interpretation of ,radium4 ,by ,f4 ,,soddy4 #bg4 ,criminal ,man4 ,by ,,cesare ,,lombroso4 #bh4 ,the ,origin of ,life4 ,by ,h4 ,,charlton ,,bastian4 #bi4 ,the ,bacillus of ,long ,life4 ,by ,,loudon ,m4 ,,douglas4 ,for list of works in preparation see end of this volume 99 99 99 99 99 ,a ,selection from the ,catalogue of ,g4 ,p4 ,,putnam',s ,,sons ,complete ,catalogue sent on application ,putnam's ,science ,series #a4--,the ,study of ,man4 ,by ,professor ,a4 ,c4 ,,haddon1 ,m4,a41 ,d4,sc41 ,m4,r4,i4,a4 ,fully illustrated4 #h1 net #b4jj4 ,a timely and useful volume4444 ,the author wields a pleasing pen and knows how to make the subject attractive4444 ,the work is calculated to spread among its readers an attraction to the science of anthropology4 ,the author's observations are exceedingly genuine and his descriptions are vivid4--,london ,athenum4 #b4--,the ,groundwork of ,science4 ,a ,study of ,epistemology4 ,by ,,st4 ,,george ,,mivart1 ,f4,r4,s4 #h1 net #a4ge4 ,the book is cleverly written and is one of the best works of its kind ever put before the public4 ,it will be interesting to all readers1 and especially to those interested in the study of science4--,new ,haven ,leader4 #c4--,rivers of ,north ,america4 ,a ,reading ,lesson for ,students of ,geography and ,geology4 ,by ,,israel ,c4 ,,russell1 ,professor of ,geology1 ,university of ,michigan1 author of ,lakes of ,north ,america1 ,glaciers of ,north ,america1 ,volcanoes of ,north ,america1 etc4 ,fully illustrated4 #h1 net #b4jj4 ,there has not been in the last few years until the present book any authoritative1 broad rsum on the subject1 modified and deepened as it has been by modern research and reflection1 which is couched in language suitable for the multitude4444 ,the text is as entertaining as it is instructive4--,boston ,transcript4 #d4--;,earth ,sculpture2 or1 ,the ,origin of ,land-,forms4 ,by ,,james ,,geikie1 ,,ll4,d41 ,d4,c4,l41 ,f4,r4,s41 etc41 ,murchison ,professor of ,geology and ,mineralogy in the ,university of ,edinburgh2 author of ,the ,great ,ice ,age1 etc4 ,fully illustrated4 #h1 net #b4jj4 ,this volume is the best popular and yet scientific treatment we know of the origin and development of land-forms1 and we immediately adopted it as the best available text-book for a college course in physiography4444 ,the book is full of life and vigor1 and shows the sympathetic touch of a man deeply in love with nature4--,science4 #e4--,volcanoes4 ,by ,t4 ,g4 ,,bonney1 ,f4,r4,s41 ,university ,college1 ,london4 ,fully illustrated4 #h1 net #b4jj4 ,it is not only a fine piece of work from a scientific point of view1 but it is uncommonly attractive to the general reader1 and is likely to have a larger sale than most books of its class4--,springfield ,republican4 #f4--;,bacteria3 ,especially as they are related to the economy of nature1 to industrial processes1 and to the public health4 ,by ,,george ,,newman1 ,m4,d41 ,f4,r4,s4 7,edin471 ,d4,p4,h4 7,camb471 etc41 ,demonstrator of ,bacteriology in ,king's ,college1 ,london4 ,with #bd micro-photographs of actual organisms and over #gj other illustrations4 #h1 net #b4jj4 ,dr4 ,newman's discussions of bacteria and disease1 of immunity1 of antitoxins1 and of methods of disinfection1 are illuminating1 and are to be commended to all seeking information on these points4 ,any discussion of bacteria will seem technical to the uninitiated1 but all such will find in this book popular treatment and scientific accuracy happily combined4--,the ,dial4 #g4--;,a ,book of ,whales4 ,by ,f4 ,e4 ,,beddard1 ,m4,a41 ,f4,r4,s4 ,illustrated #h4 #b4jj4 ,mr4 ,beddard has done well to devote a whole volume to whales4 ,they are worthy of the biographer who has now well grouped and described these creatures4 ,the general reader will not find the volume too technical1 nor has the author failed in his attempt to produce a book that shall be acceptable to the zoologist and the naturalist4--,n4 ,y4 ,times4 #h4--;,comparative ,physiology of the ,brain and ,comparative ,psychology4 ,with special reference to the ,invertebrates4 ,by ,,jacques ,,loeb1 ,m4,d41 ,professor of ,physiology in the ,university of ,chicago4 ,illustrated4 #h4 #a4ge4 ,no student of this most interesting phase of the problems of life can afford to remain in ignorance of the wide range of facts and the suggestive series of interpretations which ,professor ,loeb has brought together in this volume4--,,joseph ,,jastrow1 in the ,chicago ,dial4 #i4--,the ,stars4 ,by ,professor ,,simon ,,newcomb1 ,u4,s4,n41 ,nautical ,almanac ,office1 and ,johns ,hopkins ,university4 #h4 ,illustrated4 ,net4 #b4jj4 7,by mail1 #b4jj47 ,the work is a thoroughly scientific treatise on stars4 ,the name of the author is sufficient guarantee of scholarly and accurate work4--,scientific ,american4 #aj4--,the ,basis of ,social ,relations4 ,a ,study in ,ethnic ,psychology4 ,by ,,daniel ,g4 ,,brinton1 ,a4,m41 ,m4,d41 ,,ll4,d41 ,sc4,d41 ,late ,professor of ,american ,archology and ,linguistics in the ,university of ,pennsylvania2 ,author of ,history of ,primitive ,religions1 ,races and ,peoples1 ,the ,american ,race1 etc4 ,edited by ,,livingston ,,farrand1 ,columbia ,university4 #h4 ,net1 #a4ej 7,by mail1 #a4fj47 ,professor ,brinton has shown in this volume an intimate and appreciative knowledge of all the important anthropological theories4 ,no one seems to have been better acquainted with the very great body of facts represented by these sciences4--,am4 ,journal of ,sociology4 #aa4--;,experiments on ,animals4 ,by ,,stephen ,,paget4 ,with an ,introduction by ,lord ,lister4 ,illustrated4 #h4 ,net1 #b4jj4 7,by mail1 #b4bj47 ,to a large class of readers this presentation will be attractive1 since it gives to them in a nut-shell the meat of a hundred scientific dissertations in current periodical literature4 ,the volume has the authoritative sanction of ,lord ,lister4--,boston ,transcript4 #ab4--;,infection and ,immunity4 ,with ,special ,reference to the ,prevention of ,infectious ,diseases4 ,by ,,george ,m4 ,,sternberg1 ,m4,d41 ,,ll4,d41 ,surgeon-,general ,u4 ,s4 ,army 7,retired74 ,illustrated4 #h4 ,net1 #a4ge 7,by mail1 #a4ij47 ,a distinct public service by an eminent authority4 ,this admirable little work should be a part of the prescribed reading of the head of every institution in which children or youths are gathered4 ,conspicuously useful4--,n4 ,y4 ,times4 #ac4--;,fatigue4 ,by ,a4 ,,mosso1 ,professor of ,physiology in the ,university of ,turin4 ,translated by ,,margaret ,,drummond1 ,m4,a41 and ,w4 ,b4 ,,drummond1 ,m4,b41 ,c4,m41 ,f4,r4,c4,p4,e41 extra ,physician1 ,royal ,hospital for ,sick ,children1 ,edinburgh2 ,author of ,the ,child4 ,his ,nature and ,nurture4 ,illustrated4 #h4 ,net1 #a4ej4 ,a book for the student and for the instructor1 full of interest1 also for the intelligent general reader4 ,the subject constitutes one of the most fascinating chapters in the history of medical science and of philosophical research4--,yorkshire ,post4 #ad4--;,earthquakes4 ,in the ,light of the ,new ,seismology ,by ,,clarence ,e4 ,,dutton1 ,major1 ,u4 ,s4 ,a4 ,illustrated #h4 ,net1 #b4jj4 7,by mail1 #b4bj47 ,the book summarizes the results of the men who have accomplished the great things in their pursuit of seismological knowledge4 ,it is abundantly illustrated and it fills a place unique in the literature of modern science--,chicago ,tribune4 #ae4--,the ,nature of ,man4 ,studies in ,optimistic ,philosophy4 ,by ,,lie ,,metchnikoff1 ,professor at the ,pasteur ,institute4 ,translation and introduction by ,p4 ,,chambers ,,mitchell1 ,m4,a41 ,d4,sc4 ,oxon4 ,illustrated4 #h4 ,net1 #a4ej4 ,a book to be set side by side with ,huxley's ,essays1 whose spirit it carries a step further on the long road towards its goal--,mail and ,express4 #af4--,the ,hygiene of ,nerves and ,mind in ,health and ,disease4 ,by ,,august ,,forel1 ,m4,d41 formerly ,professor of ,psychiatry in the ,university of ,zurich4 ,authorized ,translation4 #h4 ,net1 #b4jj4 7,by mail1 #b4bj47 ,a comprehensive and concise summary of the results of science in its chosen field4 ,its authorship is a guarantee that the statements made are authoritative as far as the statement of an individual can be so regarded4 #ag4--,the ,prolongation of ,life4 ,optimistic ,essays4 ,by ,,lie ,,metchnikoff1 ,sub-,director of the ,pasteur ,institute4 ,author of ,the ,nature of ,man4 etc4 #h1 ,illustrated ,net1 #b4ej4 7,by mail1 #b4gj47 ,popular ,edition4 ,with an introduction by ,prof4 ,,charles ,s4 ,,minot4 ,net1 #a4ge4 ,in his new work ,professor ,metchnikoff expounds at greater length1 in the light of additional knowledge gained in the last few years1 his main thesis that human life is not only unnaturally short but unnaturally burdened with physical and mental disabilities4 ,he analyzes the causes of these disharmonies and explains his reasons for hoping that they may be counteracted by a rational hygiene4 #ah4--,the ,solar ,system4 ,a ,study of ,recent ,observations4 ,by ,prof4 ,,charles ,,lane ,,poor1 ,professor of ,astronomy in ,columbia ,university4 #h4 ,illustrated4 ,net1 #b4jj4 ,the subject is presented in untechnical language and without the use of mathematics4 ,professor ,poor shows by what steps the precise knowledge of to day has been reached and explains the marvellous results of modern methods and modern observations4 #ai4--;,climate--,considered ,especially in ,relation to ,man4 ,by ,,robert ,,decourcy ,,ward1 ,assistant ,professor of ,climatology in ,harvard ,university4 #h4 ,illustrated4 ,net1 #b4jj4 ,this volume is intended for persons who have not had special training in the technicalities of climatology4 ,climate covers a wholly different field from that included in the meteorological text-books ,it handles broad questions of climate in a way which has not been attempted in a single volume ,the needs of the teacher and student have been kept constantly in mind4 #bj4--;,heredity4 ,by ,j4 ,,arthur ,,thomson1 ,m4,a41 ,professor of ,natural ,history in the ,university of ,aberdeen2 ,author of ,the ,science of ,life1 etc4 #h4 ,illustrated4 ,net1 #c4ej4 ,the aim of this work is to expound1 in a simple manner1 the facts of heredity and inheritance as at present known1 the general conclusions which have been securely established1 and the more important theories which have been formulated4 #ba4--;,age1 ,growth1 and ,death4 ,by ,,charles ,s4 ,,minot1 ,james ,stillman ,professor of ,comparative ,anatomy in ,harvard ,university1 ,president of the ,boston ,society of ,natural ,history1 and ,author of ,human ,embryology1 ,a ,laboratory ,text-book of ,embryology1 etc4 #h4 ,illustrated4 ,this volume deals with some of the fundamental problems of biology1 and presents series of views 7the results of nearly thirty years of study71 which the author has correlated for the first time in systematic form4 #bb4--,the ,interpretation of ,nature4 ,by ,c4 ,,lloyd ,,morgan1 ,,ll4,d41 ,f4,r4,s4 ,crown #hvo4 ,net1 #a4be4 ,dr ,morgan seeks to prove that a belief in purpose as the causal reality of which nature is an expression is not inconsistent with a full and whole-hearted acceptance of the explanations of naturalism4 #bc4--,mosquito ,life4 ,the ,habits and ,life ,cycles of the ,known ,mosquitoes of the ,united ,states2 ,methods for their ,control2 and ,keys for ,easy ,identification of the ,species in their ,various ,stages4 ,an account based on the investigation of the late ,james ,william ,dupree1 ,surgeon-,general of ,louisiana1 and upon the original observations by the ,writer4 ,by ,,evelyn ,,groesbeeck ,,mitchell1 ,a4,b41 ,m4,s4 ,with #fd ,illustrations4 ,crown #hvo4 ,net1 #b4jj4 ,this volume has been designed to meet the demand of the constantly increasing number of students for a work presenting in compact form the essential facts so far made known by scientific investigation in regard to the different phases of this1 as is now conceded1 important and highly interesting subject4 ,while aiming to keep within reasonable bounds1 that it may be used for work in the field and in the laboratory1 no portion of the work has been slighted1 or fundamental information omitted1 in the endeavor to carry this plan into effect4 #bd4--,thinking1 ,feeling1 ,doing4 ,an ,introduction to ,mental ,science4 ,by ,e4 ,w4 ,,scripture1 ,ph4,d41 ,m4,d41 ,assistant ,neurologist ,columbia ,university1 formerly ,director of the ,psychological ,laboratory at ,yale ,university4 #ahi ,illustrations4 #b;d ,edition1 ,revised and ,enlarged4 ,crown #hvo4 ,net1 #a4ge4 ,the chapters on ,time and ,action1 ,reaction ,time1 ,thinking ,time1 ,rhythmic ,action1 and ,power and ,will are most interesting4 ,this book should be carefully read by every one who desires to be familiar with the advances made in the study of the mind1 which advances1 in the last twenty-five years1 have been quite as striking and epoch-making as the strides made in the more material lines of knowledge4--,jour4 ,amer4 ,med4 ,ass'n41 ,feb4 #bb1 #aijh4 #be4--,the ,world's ,gold4 ,by ,l4 ,,de ,,launay1 ,professor at the cole ,superieure des ,mines4 ,translated by ,orlando ,cyprian ,williams4 ,with an ,introduction by ,charles ,a4 ,conant1 author of ,history of ,modern ,banks of ,issue1 etc4 ,crown #hvo4 ,net1 #a4ge4 ,m4 de ,launay is a professor of considerable repute not only in ,france1 but among scientists throughout the world4 ,in this work he traces the various uses and phases of gold2 first1 its geology2 secondly1 its extraction2 thirdly1 its economic value4 #bf4--,the ,interpretation of ,radium4 ,by ,,frederick ,,soddy1 ,lecturer in ,physical ,chemistry in the ,university of ,glasgow4 ,crown #hvo4 ,with ,diagrams4 ,net1 #a4ge4 ,as the application of the present day interpretation of ,radium 7that it is an element undergoing spontaneous disintegration7 is not confined to the physical sciences1 but has a wide and general bearing upon our whole outlook on ,nature1 ,mr4 ,soddy has presented the subject in non-technical language1 so that the ideas involved are within reach of the lay reader4 ,no effort has been spared to get to the root of the matter and to secure accuracy1 so that the book should prove serviceable to other fields of science and investigation1 as well as to the general public4 #bg4--;,criminal ,man4 ,according to the ,classification of ,,cesare ,,lombroso4 ,briefly ,summarized by his ,daughter1 ,gina ,lombroso ,ferrero4 ,with #cf ,illustrations and a ,bibliography of ,lombroso's ,publications on the ,subject4 ,crown #hvo4 ,net1 #b4jj4 ,signora ,guglielmo ,ferrero's rsum of her father's work on criminal anthropology is specially dedicated to all those whose office it is to correct1 reform1 and punish the criminal1 with a view to diminishing the injury caused to society by his anti-social acts2 also to superintendents1 teachers1 and those engaged in rescuing orphans and children of vicious habits1 as a guide in checking the development of evil germs and eliminating incorrigible subjects whose example is a source of corruption to others4 99 99 99 99 99 ,the most valuable production since ,darwin's ,origin of ,species4 ,the ,nature of ,man ,studies in ,optimistic ,philosophy ,by lie ,metchnikoff ,sub-,director of the ,pasteur ,institute1 ,paris ,translated with an ,introduction by ,p4 ,chambers ,mitchell ,secretary of the ,zological ,society ,octavo4 ,illustrated4 ,popular ,edition4 #a4ej net4 ,by mail1 #a4fe ,it is not often that a scientific book may be read with ease1 profit1 and pleasure by the general reader1 so that ,m4 ,metchnikoff's book comes in the nature of an agreeable surprise4 ,it is marked by a refreshing navet and a large simplicity which are characteristically ,russian4 ,the scientific importance of this work is so great that it is spoken of in ,england as the most valuable production since ,darwin's ,origin of ,species4 ,opinions of the ,press ,an extremely interesting and typical book4444 ,with a distinguished frankness1 ,m4 ,metchnikoff defines his attitude to our universal prepossessions4 ,it is his theory that the infirmities of age are to be overcome4 ,if there be ground for this conception1 humanity is to be profoundly changed and what we call life now1 will be the childhood and youth of that longer and larger life4--,h4 ,g4 ,,wells1 in ,london ,speaker4 ,undoubtedly a great book 7in some quarters it has been hailed as the greatest since ,darwin's famous message to the world7 and should be read by all intelligent men and women4--,the ,nation4 ,a book to be set side by side with ,huxley's ,essays1 whose spirit it carries a step further on the long road towards its goal4--,mail and ,express4 ,new ,york--,g4 ,p4 ,putnam's ,sons--,london 99 99 99 99 99 ,remarkable for its simple language and clear style4444 ,bears the stamp of a production of an erudite scientist and a deep thinker4--,science4 ,the ,prolongation of ,life ,optimistic ,essays ,by lie ,metchnikoff ,author of ,the ,nature of ,man1 etc4 #hvo4 ,illustrated ,popular ,edition4 #a4ge net ,by mail1 #a4ij ,m4 lie ,metchnikoff is one of those rare scientists who have found a way to lay hold of and present to the world in untechnical phraseology1 intelligible to the lay mind1 such results of his researches as are of universal interest and go straight home to the bosoms and business of intelligent men4 ,the ,nature of ,man1 by the same author1 was one of the most fascinating books1 at once popular1 and scientific1 which have appeared for decades4 ,the book here in question will stand beside it as a worthy companion volume4 ,it is satisfactory to report that1 absorbed as ,metchnikoff is in material problems1 and deep as he is in the mysteries of the physical universe1 these essays show him to be an optimist who speaks with no uncertain voice4 ,a great deal of attention is given in ,the ,prolongation of ,human ,life to the subject of old age and its causes1 with scientific observations of special cases among human beings and the lower animals4 ,the author suggests means of prolonging life and health1 while contemplating natural death with serenity1 and finding that agreeable sensations accompany its approach4 ,beyond a certain point it seems to him a disadvantage to prolong life4 ,passing on from these mortuary lucubrations1 the essays concern themselves with psychological matters1 with optimism and pessimism and in general with questions of science and morals4 ,the temperaments of certain great men are analyzed in studies that have for their subjects respectively ,byron1 ,leopardi1 ,schopenhauer1 and ,goethe4 ,in the preface the author says that he has avoided1 as far as possible1 repeating points which have been sufficiently treated in ,the ,nature of ,man4 ,g4 ,p4 ,,putnam',s ,,sons ,,new ,,york ,,london