DR. T€IUDICEIU&1 ON THE 114 X.-On the Putrefaction of Rile and the Anatysis and Theory of Gallstones. By DR.THUDICHUM In October 1859 I communicated to the Medical Society of London a Paper in which I described casts of the biliary ducts which I had discovered in the centre of human gallstones. As these casts consisted principally of brown colouring matter of bile or that modification of cholochrorne termed cholophaeine I first studied the chemical nature of that substance in order the better to understand its bearing on the processes in which it played so conspicuous a part. The results of these inquiries I Communicated to the Physiological Section of the British Association for the Advancement of Science at the Oxford Meeting in ISSO and an PUTBEFACTIOX OF BILE.abstract of my communication has appeared in the ‘‘British Medical Journal” for July l4th 1860. I proved that cholochrome is an amido-acid ; that it is decomposed by nitrous acid with evolution of nitrogen and yields a new acid--cholochromic acid,-which is free from nitrogen and in its crystallized state resembles the sub- stance termed by Vircho m ‘‘ hEmatoYdine,” but nevertheless differs from it in many particular properties. I described several other products of decomposition and reactions of cholochrome and among them the most important one viz, that it is precipitated during the putrefaction of bile from the solution in which it was field by the healthy fluid. This led to the re-investigation uf the process of putrefaction of bile which had already been instituted by former observers; and I was not merely enabled to confirm the principal features of the description given by Gorup-B esanez but also to add some new facts explain the origin of some substances discovered by him and construct a theory of this process of decom- position which led me up almost in a straight line to the theory of gallstones.On subjecting large quantities of material to chemical analysis these concretions yielded the same substances as those which made up the deposit of putrid bile with the sole exception of mucus of which little or none could be found in gallstones. Of these researches I gave a short account to the British Medical Association at their Annual Meeting held in 1860 at Torquay.While able to accompany the leading ideas by the exhibition of specimens progressively proving every step of my analyses the limitation of the time imposed upon me by circumstances on that occasion did not permit me to do justice to the subject. I there-fore more fully expounded my ideas before the Medical Society of London in a Paper read before them on October 8th 186Q,and reported in abstract in the rc British Medical Journal” for Octo- ber 13th and the contemporaneous numbers of the other medical periodicals. I then exhibited cholachrome cholic acid and earthy salts as essential constituents of gallstones in man and animals. I characterized the cholesterine in gallstones of man as a secondary ingredient calling for new analyses to prove the freedom from cholic acid of concretions reported to have consisted of pure chole- sterine Having come to the conviction that the binding material of gallstones is cholic and choloidic acid I eliminated as untenable the idea of an inspissation of mucus in the formation of these con-cretions which had hitherto been the groundwork of all speculations upon their origin.116 DR. THUDICIIUM ON THE In the present communication I propose to give a short analysis of my results as a preliminary guide to the reader and then to describe the chemical proceedings which I adopted for the purpose of ascertaining the composition of human and bovine gallstones and of ox-bile Theory of Gallstones In some examinations of human gallstones I had found a resinous biliary matter ; but owing to the small quantity and the refrac- tory nature of the substance and particularly to the difficulty of separating it I had not been able to identify it.The examination of some ox-gallstones afforded an opportunity for settling this point. I extracted a large quantity of cholic and choloidic acid fromethem,-a quantity such as could never be derived from any bile with which the calculi might be supposed to have been soaked at the time they were taken out of the gall-bladder. There could be no doubt that both cholic and choloidic acids had been deposited together with the cholochrome during the pathic process in the living animal. The presence in almost all biliary concretions of some earthy and alkaline salts points in the same direction.They are and were in my analyses either present as phosphates and carbonates of lime and magnesia and could be extracted by hydrochloric acid or they were combined with the colouring matter of bile and with stearic and palmitic acid. In gallstones from man the colouring matter was accompanied by a larger proportion of inorganic salts; but in gallstones of the ox the quantity of cholochrome preponderated to so extraordinary a degree over the earthy matter that it must be assumed to be present in the free state and not as Bramson supposed it to be always viz. combined with lime. Cholochrome cholic and choloidic acids and earthy salts thus present themselves as substances without the concurrence of which the more common forms of gallstones would rarely be formed; they are in other words essential ingredients of gallstones.In man gallstones contain a large amount of cholesterine in most cases but that is a secondary ingredient as the phosphatic crust is of the uric acid or oxalate of lime calculus from the urinary bladder and is mostly crystallized around the other matters forming the nucleus. There are human gallstones which like those from the ox contain 110 cholesterine. Others are said to consist entirely of chole- PUTREFACTION OF BILE. sterine,-a statement which has to be verified by fresh analyses which must prove the absence of cholic and choloidic acid. In gallstones from man stearate and palmitate of lime are mostly present; and it remains to be seen how far those substances can assist in effecting the coricretion of the detached particles of cholo- chrome which 1 now ascribe to the cholic and choloidic acid.Let us therefore dismiss the hypothesis of the inspissated mucus or the inspissated bile which figure in our pathogeny as the mortar which combines the particles of the nucleus mucus is not found in gallstones; and an inspissation in the midst of fluid bile is quite incomprehensible. Moreover even an indubitable inspissation of bile could not lead to an insoluble concretion. We may therefore reject this hypothesis and admit that the binding material of the nucleus of gallstones is cholic mid or choloidic acid or both. The process by which gallstones are formed appears analogous to that which produces that rare description of calculus in the urinary passages,-t!ie phosphatic or fusible calculus.It is a decomposition of the bile akin to putrefaction. The compound amido-acids split up into their constituents under the influence of a cause which remains to be ascertained but is probably a putrid ferment absorbed from the intestinal canal. Under the influence of a little acetic acid formed out of glycocoll and some other new acid produced by the putrefactive change perhaps valerianic acid cholochrome a quantity of cholic acid and a portion of choloidic acid together with some salts and little fat are deposited. This is the process in the ox and sometimes in man. But the bile of man differs in this respect from that of the ox that it contains cholesterine while that of the ox contains at the most only a very small quantity as compared to the other.This cholesterine is dissolved in the taurocholate of soda. But as soon as the acid of this salt is decomposed the cholesterine is set free crystallizes and deposits upon any particle that may happen to be wjthiu easy distance in the manner of all crystals which like to post them- selves upon prominent bodies. Numerous are the modifications which this process may iindergo ; but their discussion must be reserved for future occasions. The presence of chloride of sodium iron copper and other inorganic matters in gallstones has no doubt a significance in each case but a subordinate one. In some gallstones from the ox I have again found a sulphurous compound already observed by Bolle in 1852.W-hen boiled with hydrochloric acid they gave out vapours which IIR TIlUDICHUM ON THE smelt like sulphuretted hydrogen and blackened lead-paper. coilected them in caustic potassa mixed with some solution of arsenious acid. On subsequent acidification a yellow somewhat orange-coloured deposit of a sulphur-compound of arsenic was formed; but after drying it had become brown and hard and on sublimation yielded tersulphide of arsenic besides leaving a quaii- tity of charcoal; thus proving that the gas was a compound of a carbonaceous and a sulphurous body in a volatile form or a mix-ture of two analogous substances. Putrefuction of Bile. Some large bottles full of bile and well stoppered had been allowed to stand for the period of two years and one year respec- tively.The bile had assumed a fecbly acid reaction a bright pork wine colour and had deposited a copious flaky green and brown deposit mixed with white chalk-like particles and greenish crystals. This deposit on analysis was found to cousist of cholochrome cholic acid phosphate of lime and magnesia irr dichroic crystals and mucus. The fluid part of the bile was found to contain prin- cipally choloidate of soda with little clioiate taurine valerianate and acetate of soda and ammonia phosphate of soda but no glyco- coll nor any glycocholic or taurocholic acid. It mas quite clear that the bile had spontaneously undergone a decomposition similar to that which is effected by boiling with acids or alkalies,-a decomposition wliicln in its main features has already been described by Gorup-B esanee Glychocolic and taurochdic acids had split respectively into glycocoll taurine and cholic acid.The cholate probably or some other decomposing substance had yielded valerianic acid which had combined with soda or with ammonia which latter probably originated in the decom- position of glycocoll. This compound being the amido-acid of acetic acid no doubt in this process as in the putrefaction of urine yielded the acetic acid which combined with the necessary amount of soda and precipitated a portion of the cholic acid while the greater portion of this acid remained in solution combined with soda and became further metamorphosed into choloidic acid and perhaps other products of decomposition of an acid nature.The cholochrome had no doubt been precipitated by the new acid before cholic acid as its acid properties are much less pronounced. PCTREFACTION OF BILE. The port wine colour of the fluid was probably due to some rneta- morphosed cholochrome possibly cholochromic acid or a derivate. That cholochrome cholic acid and crystallized phosphates are precipitated in this process had not been observed by Gorup- B e s an e z who had also neither found valerianic acid nor explained the origin of the acetic acid which he undoubtedly discovered.* These observations then and the theory of the process are my own additions to the doctrine. Gorup-Besanez extracted also a mixture of fatty acids from putrid bile among which he believed to have recognized margaric acid.This acid or its fellow stearic acid is a component of the first deposit formed in putrid bile. But like cholesterine in ox-bile this ingredient is too easily lost sight of‘ in consequcnce of the small quantity in which it is present. When Gorup-Besanez allowed bile to decompose at a tempe- rature of from 25O to 30”R1exposed to the free access of the air for a period of three weeks he obtained choloidic acid as the prin- cipal product of decomposition. When however he exposed bile to the air for three months in a cellar at a temperature varying between looand 12’R he found cholic acid instead of choloidic. In both cases the decomposed mass had an offensive ammoniacal smell and a marked alkaline reaction Taking into consideration only one element viz.that of time he concluded that choloidic acid was the forerunner of cholic acid ; that the latter was produced from the former; that the prescnce of cholic acid was evidence of a more advanced stage of decomposition than that of choloidic acid. But he omitted to take into consideration the most important fact -that the specimen of bile which yielded the cholic acid had been subjected to a much lower temperature than the specimens which yielded the choloidic acid and had thus bcen influenced by cir- cumstances which above all others retard the decomposition of animal matters. His assumption therefore while unsupported by any direct proof is opposed by the fact that we know choloidic acid only as a product of decomposition of cliolic acid; that we cannot reproduce cholic from choloidic acid; and further by the results of my own investigations which showed that bile after one year’s and after two years’ decomposition contained principally choloidic acid; a portion of this biliary element only being preci- pitated in the form of cliolic acid.This precipitnte it is but right * Ann. Ch.Pbarm. lix 129. 120 DR. TRUDICRUM ON TIIE to conclude was produced at a time when cholic acid prevailed for had choloidic acid prevailed at the time of the formation of the new acid (acetic valerianic and. others) the deposit must have consisted of choloidic acid or at least contained some clioloidic acid while in fact it contained hardly any or none.No cholic acid remained in solution. On account of these facts I believe that we must reverse the order of succession assigned to those acids by Gorup-Besanez giving to cholic acid priority in time to choloidic acid ultimate supremacy and ascribing to its break-tip into the fatty acids above-mentioned the destruction of the biliary state. Bile decomposed at a moderate temperature during nine months mas found by Gorup-Besanez to exhibit an acid reaction due to the presence of acetic acid in a free state. It consequently had the same reaction as the specimens examined by myself He does not state in what condition the biliary acid was present; which is much to be regretted as free acetic acid could not be present so long as any cholate or choloidate remained in solution the acids of which salts in his analyses he always precipitated by acetic acid.Diagram exhibiting the Decomposition of Bile. First Stage. The bile is neutral or alkaline. Taurocholate of soda yields {Cholate Taurine,of soda. (Cholate of soda. Glycocholate of soda yields ~Glycocoll. Margarate (Palmitate) and stearate of lime Phosphate of lime and magnesia Second Stage. The bile becomes acid by tlie supervention of a new (valerianic 3) acid whose origin is undecided. Cholate of soda deposits cholic acid. Soda-salt of new acid is formed. Cholochrome (Cholophaeic acid) is precipitated aud partly trans -formed into soluble cholochromate (3) (Acetic acid.Glycocoll yields Amlnonia. PUTREFACTIOS OF BILE. Third Stage. The bile continues acid. Cholate of soda is transformed into choloidate. The latter deposits some choloidic acid (?). Choloidate of soda yields fatty acids products of decomposition ; among them probably derived from glycocoll acetic acid in the free (?) state. The alkaline condition during the first stage observed by Gorup- Besanez occurs only when bile putrefies at a high temperature SO that the mucus uiidergocs active decomposition and produces ammoniacal compounds. The bile upon which I operated at low temperatures and with moderate access of air T could not at any time discover to be alkaline. In one case Gorup-Besanez observed the acid reaction to give may to a second alkaline reaction but did not notice any corresponding essential changes.Owing to these uncertainties I have not distinguished as stages the neutral alkaline acid and last alkaline conditions. Gorup-Besanez is of opinion that the decomposition of the primary biliary acids is not effected until an acid reaction of the bile appears; because only at that juncture does acetic acid produce a precipitate of cholic or clioloidic acid. But this negative test appears to me only relative because the acids may be decomposecl and yet acetic acid may produce no immediate precipitate more acetic acid being required to cause a precipitate at the period when the bile is yet neutral or alkaline and when no adventitious acid has yet taken the edge off the alkaline phosphate of soda which is invariably present in bile and though not very evident to test-paper neutralises some acid before an acid reaction can become established.To the naked eye the first stage is characterized by the deposition of white gra- nules partly on the top of the fluid partly at the bottom partly against the walls of the vessel whieh consist of palmitate stearate and phosphate of lime. All the stages no doubt gradually pass into each other; and the above diagram while considered useful for illustration must not be considered as an absolute syllabus of a variable process. Analysis of human gallstones. I must here distinpish between the general analysis of gall. stones by which the essential constituents are found and those special processes which are directed to the isolation of certain less VOL.XIV. K DR. TIIUDICHUM ON TIKE frequent ingredients such as copper manganese sulphides or uric acid. Those human gallstones which consist principally of cholochrome are to be analysed by the process which will be detailed lower down as applicable to gallstones from cattle. For the analysis of the cominon cholesterine concretion from man the following process will be found suitable. The powder of the calculi is gradually thrown into hot benzole contained in a flask placed on a sand-bath. The cholesterine and biliary matters are dissolved while cholochrome earthy phos- phates earthy salts of fatty acids and any other ingredients remain suspended and unchanged.Solution and residue are separated by filtration. The matter on the filter is washed with repeated quantities of benzole lastly with cold alcohol and dried. It then presents itself as a brown powder which is very delicate to the touch imparting an almost velvety feel. Treated on the filter with absolute ether containing little nitric acid it yields fatty acids to the ether which on distillation of the ether from the filtrate are deposited in a granular and crystalline form. If the residue on the filter is next treated with water phosphate and nitrate of lime and magnesia are extracted and remain as phos-phates and carbonates sometimes coloured blue by copper on evaporation of the solution and incineration of the residue. The colouring matter extracted with ether and nitric acid and water is free from fatty matter but retains some earths which can only be obtained by burning the cholochrome or by dissolving it in carbonate of alkali when the earthy and other insoluble inor- ganic and organic matters remain behind.They are then inciner- ated and the ashes added to the earths extracted by aFid and water. The carbonate of lime may be recognized by the effervescence which takes place on dissolving the earthy salts in hydrochloric acid. The subsequent addition of ammonia in excess precipitates the phosphates while the lime which before had been as carbo- nate remains in solution and may be precipitated by phosphate of soda or oxalate of ammonia. From the original benzole solu- tion cholesterine is best obtained by evaporating the solvent and treating the residue with boiling spirit of wine.On cooling the cholesterine which before had been greenish crystallises in the usual glistening white plates while the solution retains the brownish-green coloured biliary matters. On evaporation a small quantity of a mixture of cholesterine and fat is deposited. That PUTRl$FAC'ITON OF BILE and the rest of the alcohol being removed there remains a brown resinous mass insoluble in water soluble in alcohol and soluble in caustic potassa; an excess of caustic ley added to the solution causes the separation of a resinous salt which floats on the top of the caustic fluid. From the solution in potassg it is pre-cipitated by hydrochloric acid It combines with lime and baryta forming insoluble compounds and is therefore choloidic acid though brown and impure and perhaps as suggested by the analysis of ox-gallstones mixed with some cholic acid.It yields a small quantity of matter to boiling water ;but the nature of this extract could not be determined by crystallization as was the case in the analogous extract from ox-gallstoues. Tn his directions for analysing human gallstones Sim on refers hypothetically to the presence of biliary resin without however stating its presence as a positive occurrence or grasping its signi- ficance. In the ordinary analysis of gallstones which began with the extraction of the powder :by means of caustic potassa,--a pro-cess mainly directed to the purification of cholesterine choloidic (and cholic) acid remained with the cholochloine produced from which it could afterwards be scarcely separated.When the ana- lysis of gallstones had however for its principal object the pre- paration of cholophaeine the spirituous mother-liquor of chole-sterine was not thought of sufficient importance to deserve further scrutiny; and even if it had been granted it is possible that the fatty salts dissolved by the boiling spirit (which in the analysis with benzole remain undissolved and are subsequently decomposed with acid and extracted with ether and water) would have made the separation of the choloidic acid a matter of considerable difi- culty. Analysis of ox-gallstones. The gallstones are powdered and boiled with water during three hours.The dark-brown extract is removed by filtration and the residue on the filter washed during three days with boiling water -that is until the filtrate comes away colourless. The powder is then dried in the water-bath. The water-extract is evaporated. It is then boiled for several hours with alcohol of 80" strength which also acquires a dark colour and is separated by filtration. The residue is for several days washed with boiliug alcohol and dried. The primary filtrate is allowed to cool by itself and the DR. THUDlCHUM ON THE washings are evaporated by thcmselves. The alcoholic extract is further analysed as mill be detailed lower down. Thc powder is next mixed with water in a flask and a quantity of hydrochloric acid added.A slight frothing ensues and the smell of sulphuretted hydrogen is at once perceptible ; lead-paper is turned black by the gas. It is therefore necessary to perform the extraction with hydrochloric acid in a gas-evolution bottle with funnel for the addition of the wid and two tubes one for passing a current of air through the acid fluid the other for con-ducting the gases through an alkaline solution of arsenious acid coloured blue by litmus. In my first analysis this alkaline solu- tion was contained in two bottles and as soon as the acid va- pours had coloured the litmus red the first bottle was removed the second bottle put in place of the first and a new bottle in the place of the second.All the sulphuretted hydrogen was driven out of the mass by boiling and a cur-rent of air was passed through the fluid and absorbed in the alka-line fluid. The united solutions on addition of an excess of hydrochloric acid precipi- tated yellow flakes of a sulphur-compound of arsenic which collected on a filter mashed and dried weighed 1.8 grains corre-sponding to 0.743 grains of hydrosulphuric acid. On drying this precipitate became brown arid hard and on sublimation yielded tersulphide of arsenic as already stated besides a quantity of charcoal. That so small a quantity of this sulphur-compound should have been obtained from about six ounces of gallstones is explained by the experience of Bolle who analyzed two gall-stones ouly one of which yielded sulphuretted hydrogen.The residue which remains after the removal of the hydro- PUTREFACTlON OF BILE. chloric acid extract consists of cholochrome with traces only of the original admixtures. The water-extract on evaporation yields a syrup of a faintly acid reaction mainly bile. It is soluble in water and spirits and no crystalline organic compound is deposited from it even after months of repose. But it has the remarkable property of holding in solution and at length depositing in well-defined large crystals phosphate of lime. The alcoholic extract on cooling deposits a small quantity of white granular matter which is collected on a filter washed with alcohol and dried. It consists of cholic acid containing some fatty acid not easily separated.The filtrate has the property of ambergris being amber in reflected and green in transmitted light. It also has a most agreeable odour of musk. After a part of the alcohol has been distilled off and $he fluid has been again allowed to cool flakes of crystalline matter are deposited. They probably consist of cholesterine. After further evaporation a biliary acid is deposited in drops,-amorphous cholic acid. After prolonged standing crystals of the same character as those obtained by alcohol from the deposit in rotten ox-bile are deposited,-crys- tallised cholic acid. Most of them are mixed with a syrup from which they cannot be separated mechanically. This syrup is insoluble in water and becomes resinous after contact with it it has all the properties of choloidic acid.This mixture of acids is boiled for a long time with water which dissolves cholic acid and a light yellow matter,-perhaps choloidic acid though this acid is reported to be quite insoluble in water. However that may be the watery decoction when left to spontaneous evaporation which takes months owing to the formation of a pellicle on the surface at last deposits the very characteristic splendid needles of cholic acid mixed with a granular brown deposit which does not give the cholochrome reaction and may be choloidic acid. The hydrochloric acid extract is of a light brownish colour and perfectly transparent. Evdporated on the water-bath it deposits a black matter which after mixing with water becomes brown and consists of cholochrome yielding the usual reaction.Several subsequent evaporations each yield some of this deposit which ultimately becomes mixed with earths. The earths are phosphates of lime and magnesia which are deposited in a crystalline state when the solution containing but little acid is allowed to stand. By calcination they are freed from organic matter. Ultimately DR. THUDICHUM ON THE there remains a saline mass containing chloride of calcium chloride of ammonium and perhaps some traces of other matters yet to be ascertained. The ingredierits of ox-gallstones according to analyses upon the above plan are the follomirig Bile a residue of the fluid in which the concretions are formed. Cholochrome cholic and choloidic acids cliolesterine a sulphate in some cases phosphates of lime and magnesia carbonates of the same and some ammonia- compounds possibly a sulphate.* Analysis of Putrid Ox Bile.It is necessary to separate some of the white granules from the Auiil in order to show by combustion and treatment with acidu- lated ether that they contain phosphate and palmitate or stearate of lime. The free fatty acid forms an emulsion on boiling with phosphate of soda ’ The principal step in the analysis of this fluid is the filtration and separation of the deposit. A bag of twilled calico is best used for that purpose. When the fluid has percolated the smeary deposit in the bag must be kneaded with cold water as otherwise it is impossible to wash it.When well washed it is mixed with boiling alcohol and boiled with it for some time; it is then again put in the washed calico bag. The filtrate on cooling deposits a large quantity of crystallized cholic acid. The mother-liquor on evaporation yields little cholic and some choloidic acid. That part of the deposit which boiling alcohol did not dissolve is well mashed with alcohol and extracted with a boiling solution of carbonate of potassa. This solution takes up the wliole of the colouring matter cholophaeine and leaves behind a white mass of coagulated mucus mixed with greenish crystals of phosphate of lime which are separated by levigation. From the soda-solution the cholochrome is obtained as the green modification choloctdo-ine by precipitation with hydrochloric acid.The deposit therefore is made up of stearate and palmitate of lime cholic and choloidic acid cholochrome phosphate of lime in crystals and mucus. The port-nine-coloured fluid part of the bile is treated with sulphuric acid in slight excess a large quantity of choloidic acid * I may here allude to the discovery of sulphide of ammonium which Lehmann states to have made in the bile of a boy. PUTREFACTION OP BILE is then precipitated as a pitchy mass which is easily soluble in Rarm alcohol and contains but little cholic acid deposited in crystdine granules after long standing of the alcoholic solution. The excess of sulphuric acid is removed and any free acid neutralized' by boiling the fluid residue with carbonate of baryta.Wheh evaporated this solution deposits resinous cholic acid (which does not decom- pose carbonate of baryta) to be extracted by alcohol. The alcohol causes a crgsta1lizat;ion on standing with the fluid. The crystals consist of sulphate of soda phosphate of soda and taurine to be separated mechanically and in the ultimate mother-liquor of the decrystallized substances some triple-phosphate is obtained as also some chloride of ammonium to be obtained pure by sublima- tion. The alcohol retains the acetate and valerate of ammonia which salts after evaporation of the alcohol yield their acids on distillation with sulphuric acid The addition of this latter acid still precipitates some resinous biliary matters. The fluid part of putrid bile therefore contains choloidate of soda a little cholate a red colouring matter perhaps cholochromic acid taurine valerate and acetate of ammonia phosphate of soda chloride of ammonium and some other as yet undetermined matters.Putrefaction and Analysis of frilumaia Bile. c As human bile can only be obtained in quantity from persons who have died from disease it will not easily afford the materials with which to repeat the experiments instituted with ox-bile which is fresh healthy and normal. Human bile promiscuously collected in the dead-house even allowing it to contain the normal ingredients is mostly vitiated by a large amount of albumen Tyhich enters the gall-bladder by endosrnosis during the interval between death and obduction This albumen coagulates in part during evaporation of such bile on the water-bath,another part remaining dissolved.If then such bile be subjected to putrefaction the process takes place under different conditions and yields therefore different results. 'This difference mainly consists in the circumstance that the alkaline products of decomposition of albumen either neutralize the acid products of the decomposition of bile which mould pre- cipitate insoluble compounds or dissolve them again should they have been precipitated. Deducting the products of the putre- faction of albumen the products of the putrefaction of the bile GUTHRIE ON SOME PERIVATIVE itself are the Same as those obtained fr:orn ox-bile althongh they are k~a different form.Human bile is mostly neutral. When dissolved in alcohol it parts with the mucus and albumen and the filtrate after evaporation of the alcohol 'leaves a residue which is entirely soluble in water and such solution is neutral and not pre- cipitated by oxalic or acetic acid. Sometimes however human bile exhibits an acid reaction; this en similar treatment with alcohol and re-solution in water of the residue yields a plastery precipitate of choloidic acid. When complete precipitation has been effected the filtrate evaporated and the concentrated fluid treated with alcohol prismatic crystals of taurine are sometimes obtained. The solution always yields ammonia. Human bile which has been allowed to putrefy in a stoppered bottle emits a horrible odour is of a reddish brown colour and apart from the deposit perfectly clear it has an acid reaction.With acetic acid it becomes troubled and deposits a resinous precipitate; but the supernatant fluid remains thick and does not become clear even on boiling and standing; the addition of hat alcohol resolves the turbidity.