ORGANIC ANALYSIS. 



811 



1000 : 887.06 : : 0.46 : x (= 0.408) crys- 



tallinej'at. 

 1000 parts of this blood therefore consist of 



Water 804.164 



Fixed salts 7.388 



f Red particles .. 109.988 



| Albumen 72.716 



Fibrin 2.962 



Alcoholic extract 1.685 

 Watery extract . . 0.428 



Oily fat 0.253 



_Crystalline fat .. 0.408 



999.992 



Organic matters 

 188.440. 



3. Analysis of milk. 



Occasionally we may have to perform an 

 analysis of milk : we may proceed as in the 

 following instance. 



The milk was rather thin, watery in appear- 

 ance, and had a sp. gr. of 1031. It was ob- 

 tained from a woman aged 25, three weeks 

 after the birth of her fourth child. 



(a) 100 grs. evaporated to dryness left 

 11.49 grs. of solid matter. 



100 : 1000 : 11.49 : x (= 114.9) solids 



per 1000. 

 1000 114.9 = 885.1 ivaterper 1000. 



(b) On incinerating the residue, an alkaline 

 ash was left amounting to 0.24 grs. = salts 

 lAper 1000. 



(f) 158 grs. of the milk were mixed with a 

 few drops of acetic acid and evaporated to dry- 

 ness, and digested repeatedly in ether (the 

 ether was first allowed to macerate upon the 

 residue unpowdered. It was decanted and 

 the greater part of the fat thus removed ; the 

 residue was completely dried, powdered, and 

 again subjected to three or four digestions with 

 ether. All the ethereal solutions were then 

 evaporated.) The fatty matter amounted to 

 4.61 grs. 



158 : 1000 : : 4.61 : x (= 29.13) butter 

 per 1000. 



(d) The portion insoluble in ether was di- 

 gested in dilute alcohol (sp. gr. 920) as long 

 as any thing dissolved. The solution on eva- 

 poration yielded a yellowish granular mass, 

 consisting of milk sugar, and a little extractive 

 matter : it amounted to 9.7 grs. and appeared 

 perfectly free from casein. 



158 : 1000 : : 9.7 : x (= 61.39) sugar of 

 milk per 1000. 



(e) The insoluble residue consisted almost 

 entirely of casein, with a small quantity of sa- 

 line matter. Calculating by the deficiency, 

 (as, owing to an accident, it was not weighed,) it 

 amounted to 3.85 grs. 



158 : 1000 : :"s.85 : x (= 24.37) casein 

 per 1000. 



The results of the analysis may be summed 

 up as follows : 

 Water 885.1 



/- Fatty matter 29.13 



Ureanic matter, 1 j i 



& I Sugar and alco- 



G r *:, < holic extract. . 

 oaline residue, j /-, j 



'I Casein and wa- 



tery extract . . 



N 



61.39 



24.38 



1000.00 



The proportion of " extractive matter " in 

 milk varies, but I am not aware of any ready 

 method of determining its quantity, apart from 

 that of the sugar and casein. If we attempt 

 to digest casein in water, it swells up and partly 

 dissolves, becomes gelatinous, and does not 

 allow the fluid to pass through the pores of the 

 filter. If a cold saturated solution of sugar of 

 milk in proof spirit, (sp. gr. 920,) be allowed 

 to digest for a few days in a closed flask upon 

 the spirituous extract (rf), the liquid assumes a 

 yellow colour from dissolved extract, and the 

 sugar is left in white crystalline grains, but this 

 can hardly be used as a process for analysis. 

 4. Analysis of bile. 



Our methods for analysing this complicated 

 and important secretion are very inadequate. 

 Still, such as they are, I have endeavoured to 

 illustrate them by the following example : 



The bile analysed was obtained from a man 

 set. 75, who died of gangrena senilis. The 

 gall-bladder was removed entire, and the bile 

 examined 48 hours after death. 



It was a brownish, turbid, scarcely ropy 

 fluid, of sp. gr. 1024, and amounted to about 

 240 grs. 



(a) 65.16 grs. evaporated to dryness left 

 4.83 grs. This residue on incineration left 

 0.75 grs. of saline matter. 



65.16 : 1000 : : 0.75 : x (= 11.51) salts per 

 1000. 



4.83 0.75 = 4. 08 and 



65.16 : 1000 : : 4.08 : x ( 62.61) organic 

 matter per 1000. 



Therefore 1000 (11.51 + 62.61)= 925.88 

 water per 1000. 



(6) 171. 2 grs. mingled with thrice its bulk 

 of alcohol, and filtered, left a yellowish ropy 

 residue of mucus, which, when well washed 

 with alcohol and dried, amounted to 5.1 grs. 



171.2 : 1000 : : 5.1 : x (= 29.78) mucus 

 per 1000.* 



(r) The filtered liquid was evaporated nearly 

 to dryness and mingled with ether. A bright 

 yellow solution was obtained ; it was decanted, 

 and the residue repeatedly digested with ether. 

 The mixed ethereal solutions, on evaporation, 

 left 2.8 grs., of which 0.6 grs. was soluble in 

 water (being biliary matter). 



2.8 0.6 = 2.2 ethereal extract. 



(d) The ethereal extract was treated with a 

 weak solution of ammonia; a brown liquid was 

 obtained, and a white crystalline residue of 

 cholesterin was left, amounting to 0.31 grs. 



171.2 : 1000 : : 0.31 : x (= 1.81) choles- 

 terin per 1000 



2.2 0.31 = 1.89. 



171.2 : 1000 : : 1.89 :x (= 11.04) uncom- 

 bined fatty and resinous acids per 1000. 



(e) The residue insoluble in ether was treated 

 repeatedly with hot alcohol. It left undis- 

 solved a remainder, which when dry amounted 

 to 2. 92 grs. 



171.2 : 1000 : : 2.92 : x (= 17.05) watery 

 extract. 



* The proportion of matter insoluble in alcohol 

 in this instance was very great, probably it con- 

 tained something besides ordinary mucus ; but 

 circumstances prevented my examining it more 

 minutely. 



