812 



ORGANIC ANALYSIS. 



(/) An attempt was made to separate the 

 colouring matter from the alcoholic extract by 

 baryta water, and to obtain it free from baryta 

 by solution in carbonate of ammonia, but it 

 did not succeed ; indeed I have never been 

 able by this or any other process to separate the 

 colouring matter from the other ingredients of 

 the bile with sufficient accuracy to warrant its 

 adoption for analytical purposes. 



(g) The quantity of alcoholic extract was in 

 this case from the experiment with the baryta 

 necessarily inferred from the deficiency. 



Since 1000 grs. contain 74.12 of solid mat- 

 ters, 171.2 grs. will contain 12.69 ; we must, 

 therefore, deduct the ethereal and watery ex- 

 tract, and mucus : 



(2.2 + 2.92 + 5.1) 10.22 grs. 



12.69 10.22 = 2.47. Biliary and co- 

 louring matter : 



171.2 : 1000 : : 2.47 : x (= 14.37) biliary 

 matter per 1000. 



The specimen of bile thus examined, there- 

 fore, furnishes the following results : 



Water 925.88 



Mucus 29.78 



Biliary and co- ^ 1407 

 uring matter $ 



x Resinous and > 

 Fixed salts, ^ fatty acids ..{ "-04 



Cholesterin 1.81 



. Watery extract 17.05 



t; 



Organic matter, % 



62.61. 



< 



11.51. 



999.93 



M. Pettenkofer has recently proposed the 

 change of colour produced by the action of 

 sulphuric acid and sugar upon bile as a test of 

 its presence. Having freed the liquid sus- 

 pected to contain it from albumen by evapo- 

 rating to dryness and exhausting the residue 

 by boiling water, the solution is concentrated 

 by evaporation, and when cold mingled with 

 about one-third of its bulk of oil of vitriol, 

 so as to raise the temperature of the mixture 

 from 150 to 1 60 of Fahrenheit, but not higher. 

 A fe\v grains of sugar are now added to the 

 liquid, and the whole suffered to stand for a 

 few minutes. If bile be present a beautiful 

 crimson colour is developed, increasing in in- 

 tensity for some minutes. The tint is un- 

 equivocal provided the solution contain not less 

 than jLg of its weight of dry bile, or 5 ' g of the 

 recent secretion. This reaction is independent 

 of the mucus and colouring matter. 



5. Of the saliva. 



The saliva is not often the object of analysis; 

 when it is, it may be proceeded with as in the 

 following instance, in which healthy saliva was 

 examined. It was obtained several hours after 

 taking food. It had a sp. gr. of 1001.5, was 

 slightly alkaline, restoring the colour of reddened 

 litmus paper ; and was ropy and opalescent. 



(a) 111 grs. evaporated to dryness in a pla- 

 tinum capsule and incinerated, left 0.22 grs. 

 of ash. 



Ill : 1000 : : 0.22 : x (= 1.98) saline mat- 

 ter per 1000. 



(6) 500 grs. evaporated by a water-bath left 

 2.51 grs. 



500 : 1000 : : 2.51 : x(= 5.02) total solids. 

 5.02 1.98 = 3.04 organic matter. 

 1000 5.02 = 994.98 total quantity of 

 water. 



(c) The dry residue was digested in ether ; 

 the ethereal solution decanted and evaporated 

 left 0.03 grs. of an oily matter with a strong 

 peculiar odour. It contained a trace of sulpho- 

 cyanide of potassium, as was shewn by the red 

 colour struck by a very dilute solution of ses- 

 quichlonde of iron. 



500 : 1000 :: 0.03 : x (= O.OG) fattt, 

 odorous mutter with traces of sulpho- 

 cyanide potassium. 



(d) The residue undissolved by ether was 

 treated with boiling alcohol; the solution de- 

 canted and evaporated left 0.61 of a crystalline 

 yellowish deliquescent salt, in which the pre- 

 sence of sulphocyanide of potassium was 

 proved ; 1st, by its striking a blood-red liquid 

 with a very dilute solution of sesquichloride of 

 iron ; and 2ndly, this solution, according to 

 Dr. Percy's suggestion, was acidulated with 

 hydrochloric acid, and a fragment of zinc 

 dropped in. Immediate effervescence ensued 

 with a strong odour of sulphuretted hydrogen 

 due to the decomposition of the sulphocyanide. 

 Its acidulated aqueous solution gave no preci- 

 pitate with nitrate of baryta ; but after a small 

 portion of the alcoholic extract had been inci- 

 nerated and the residue dissolved in water 

 feebly acidulated with nitric acid, abundant 

 precipitation was manifest on adding a solution 

 of chloride of barium; during incineration the 

 sulphocyanide had been decomposed and the 

 sulphur, by absorbing oxygen, converted into 

 sulphuric acid. 



500 : 1000 : : 0.61 : x (= 1.22) alcoholic 

 extract. 



(e} The residue left undissolved by alcohol 

 was treated with water and thrown upon a 

 weighed filter; the insoluble portion amounted 

 to 0.68 : it consisted of mucus, debris of epi- 

 thelium, Sec. 



500 : 1000 : : 0.68 : x ( 1.36) mucus. 



(_/') The filtered solution contained traces of 

 albuminous matter (mucus) held in solution by 

 the soda. This was precipitated by exact neu- 

 tralization withaceticacid, evaporated todryness, 

 redissolved, and again filtered. This aqueous 

 liquid contained the ptyalin, or peculiar sali- 

 vary matter, and a certain proportion of watery 

 extract so called. Ptyalin has never yet been 

 obtained in a state of purity. It always contains 

 chlorides and phosphates mixed with it. The so- 

 lution was mixed with twice its bulk of alcohol, 

 by which the ptyalin in company with some 

 watery extract was precipitated. Its solution, 

 when redissolved in water, gave precipitates 

 with acetate and triacetate of lead, infusion of 

 galls, and nitrate of silver, but none with cor- 

 rosive sublimate, sesquichloride of iron, or 

 ferrocyanide of potassium, either alone or after 

 the addition of acetic acid. Each time it is 

 evaporated to dryness a small portion remains 

 behind in an insoluble form. Deducting the 

 ethereal and alcoholic extract, and mucus, 



5.02 (1.22 + 0.06 +1.36 (e))= 2.38 re- 

 presents the ptyalin and watery extract 

 per 1000. 



