CONSTITUENTS OF THE HUMAN BODY. 21 



blood, in disease, and in other fluids. Produced by Nitric acid, and again libe- 

 rated by means of Carbonate of Baryta. Composition : corresponds with the 

 cyanide of Ammonia with Water. Artificially formed by W,ohler. Colour- 

 less, four-sided prisms, or long, silky, shining needles. Spec. grav. = 1*35. 

 Scentless, it produces neither acid nor alkaline reaction ; soluble in any pro- 

 portion in boiling water. Unites as well with acids as with bases. 



b. Uric Acid [C, H 4 N 4 6 ], in the urine of animals feeding on flesh, in 

 urinary calculi, and gouty concretions. United with ammonia in the excre- 

 ments of birds (Guiino) and serpents. Forms a light, fine, white powder ; 

 with difficulty soluble in water. Is precipitated from human urine upon 

 cooling ; at first grey, then pale, rosy red ; or by the addition of nitric or mu- 

 riatic acids. Uric acid easily decomposes urea, upon which a substance re- 

 mains behind which Liebig calls Uric. Uric is one of the most feeble acids ; 

 its salts are little soluble in water. (Colouring matter of urine, an extractive, 

 mixed with salts, is reddish brown, saltish bitter, urinous odour, soluble in 

 water and alcohol, is of an amber or brownish yellow, easily decomposes, 

 decreases when living on vegetable diet.) 



II. Non-nitrogenized Materials. 



12. Sugar of milk, lactic acid, fats. 



1. Sugar of milk, [C g H 4 O 4 -{- H 0] saccharum lac'is. f of the solid con- 

 stituents of human milk consist of sugar of milk. It may be procured by 

 evaporation and crystallization from whey, that is, the fluid of tnilk deprived 

 of fat and casein. It forms white four-sided prisms. Spec. grav. = 1'543. 

 Taste slightly sweet, harder than cane sugar, easily soluble in water ; changes, 

 in time, of itself into lactic acid, as well as by rennet ; by yeast it passes into 

 grape sugar and spirituous fermentation. 



2. Lactic acid acidum ladicum. [C 6 H 5 0..] In all fluids and secretions 

 of the body, freely united to Potash, fcoda, Ammonia, Lime, and Magnesia. 

 Free in the milk, xmne, muscles, and sweat. It is colourless and scentless, 

 very acid, not volatile like acetic acid, into which it is decomposed by strong 

 heat; causes albumen and casein to coagulate, and holds phosphate of lime, 

 the principal element of the bones, in solution. It is a strong acid, separating 

 acetic acid from its compounds. Most of its salts are soluble in water, and 

 erystallizable. 



3. Fats (Pinguedines} are insoluble in water, in hot spirit and aether they 

 form soluble compounds of Carburetted Hydrogen with a little oxygen. 

 Most of them become metamorphosed by strong bases, especially alkalies and 

 oxyde of lead, into soaps, as the acid contained in them with the base is 

 transformed into a salt. We therefore distinguish the saponiliable fats from 

 the unsaponifiable (Choksterin [C 37 H 32 O], an element of the blood, of bile 

 and of neurine, frequently present in gall stones and other pathological secre- 

 tions, arid Scrotin discovered by Boudet in the blood). Fat exists free in 

 the fibro-cellular tissue and medulla of bones, or united with other substances, 

 as for example in the milk, the brain, the hair, the cerumen of the ear, 

 pus, &c. 



The base of the saponifiable fats of the human body is Glycerin, [C 6 H 7 

 5 .] a substance separated by boiling fat with oxyde of lead ; the acids which 

 unite with that base form the different kinds of fat, Stearic (or tallow) [C 68 

 H 66 s4- 2 H J an(l Margaric 2 C 34 H 33 O 3 -f H 0] acids on the one side, 

 and Hair (oil) [C 44 H 40 OJ acid on the other; lastly, Butteric [C 8 H, O a -f 

 H 0] and Cerebric acids. 



