URINE OF ANIMALS.
The urine of animals varies much in cha racter, according to the kind of food taken. Thus, there are striking differences between the urine of the carnivora and the herbivora. The urine of carnivorous animals is ge nerally acid when discharged, but becomes alkaline and ammoniacal very rapidly. The urine of herbivorous animals, on the con trary, is alkaline when passed, and contains a large proportion of alkaline and earthy car bonates. Simon, however, states the urine of horses immediately after it is passed, to be occasionally acid. The urine of the carnivora, according to the observations of Vanquelin and Hiinefeld, contains neither the uric nor hippuric acids. Hieronymi, however, who examined the urine of the lion, the tiger, and the leopard, detected uric acid in small pro portions. The urine of the herbivora con tains hippuric acid in large quantities, in the form of hippurate of soda. No uric acid is present according to the analyses of most chemists, but traces of it have occasionally been found in the urine of the graminivora.
Hieronymi obtained the following result by the analysis of the mixed urines of the lion, tiger, and leopard. This may, therefore, be regarded as the type of the urine of the car nivora : The specific gravity of the urine of these large carnivorous animals varies, according to Hieronymi, from 1059 to 1076. It is clear when passed, and of a bright yellow colour.
The urine of the herbivora is turbid when passed, and generally possesses a lower spe cific gravity than that of carnivorous animals. Thus, the urine of horses, according to Simon, is about 1045. That of oxen, according to Von Bibra, varies from 1040 to 1032.
The following are two analyses of the urine of horses by Von Bibra : Water - - - 885.09 912.84 Urea - - - - 12.44 8.36 Hippuric acid - - 12.60 1 23 Watery extractive - 21.32 19'25 Alcoholic extractive - 25.50 18.26 Mucus - - - 0.05 0.06 Salts soluble in water - 23'40l 40.00 Salts insoluble in water 18.80 With respect to the hippuric acid present, Von Bibra found that it varied extremely in proportion in different specimens of urine.
He never found that it became replaced by the benzoic acid when horses were exposed to excessive labour, an opinion which has been very generally received by chemists. He never, indeed, could detect benzoic acid under any circumstances, except in such small quantities as to require the assistance of the microscope to show its presence.
The deposit which causes the turbidity observed in the urine of the horse, is com posed as follows, according to You Bibra : Carbonate of lime - - - 80.9 Carbonate of magnesia - - 12.1 Organic matter - - - - The horses that supplied the above de scribed specimens of urine, were fed on hay and oats, and used in agriculture.
Boussingault examined the urine of a horse fed on trefoil and vetches, and states its composition as follows : Water - - - - - 910'76 Urea - - - - 31.00 Hippurate of potassa - - 4.74 Lactate of potassa - - - 11.28 Lactate of soda - - - 8.81 Bicarbonate of potassa - - 15.50 Carbonate of lime - - - 10.82 Carbonate of magnesia - - 4.16 Sulphate of potassa - - - 1.18 Chloride of sodium - - - 0.71 Silica - - - - - Phosphates, -none present.
Chemists have described a red oil as ex isting in the urine of herbivorous animals, and have attributed the peculiar odour of the secretion to the presence of that substance.
Boussingault carefully examined the urine of horses with a view to obtain this oil for examination, but failed to extract it, though he operated on twenty-six gallons. He dis tilled the whole quantity, but no trace of oil came over into the receiver. All that he ob tained was a colourless fluid, strongly im pregnated with the odour of horse's urine.
He considers this odour dependent upon the presence of a volatile acid, and believes that the volatile red oil obtained by chemists results from the decomposition of the alkaline hippurates, and that it is not produced until the urine is evaporated to dryness.