USES OF URINE AND BILE. 



27 



have no share in the process of nutrition 

 or reproduction of organized tissue. But, 

 quantitative physiology must at once and 

 decidedly reject the opinion,, that the bile 

 serves no purpose in the economy, and is 

 incapable of further change. 



No part of any organized structure con- 

 tains soda ; only in the serum of the blood, 

 in the fat of the brain, and ia the bile, do 

 we meet with that alkali. When the com- 

 pounds of soda in the blood are converted 

 into muscular fibre, membrane, or cellular 

 tissue, the soda they contain must enter into 

 new combinations. The blood which is 

 transformed into organized tissue gives up 

 its soda to the compounds formed by the 

 metamorphoses of the previously existing 

 tissues. In the bile we find one of those 

 compounds of soda. 



Were the bile intended merely for excre- 

 tion, we should find it, more or less altered, 

 and also the soda it contains, in the solid 

 excrements. But, with the exception of 

 common salt, and of sulphate of soda, 

 which occur in all the animal fluids, only 

 mere traces of soda are to be found in the 

 faeces. The soda of the bile, therefore, at 

 all events, must have returned from the in- 

 testinal canal into the organism, and the 

 same must be true of the organic matters 

 which were in combination with it. 



According to the observations of physio- 

 logists, a man secretes daily from 17 to 24 

 oz. of bile ; a large dog, 36 oz. ; a horse 37 

 Ibs. ( Burdach's Physiologie, v. p. 260.) But 

 the faeces of a man do not on an average 

 weigh more than 5 oz. ; and those of a horse 

 28^ Ibs., of which 21 Ibs. are water, and 1\ 

 Ibs. dry faeces. (Boussingault.) The latter 

 yield to alcohol only ^Vth part of their 

 weight of soluble matter. 



If we assume the bile to contain 90 per 

 cent, of water, a horse secretes daily 592 oz. 

 of bile, containing 59*2 oz. of solid matter ; 

 while 7 Ibs. or 120 oz. of dried excrement 

 yield only 6 oz. of matter soluble in alcohol, 

 which might possibly be bile. But this 

 matter is not bile ; when the alcohol is dissi- 

 pated by evaporation, there remains a soft, 

 i unctuous mass, altogether insoluble in water, 

 [and which, when incinerated, leaves no al- 

 kaline ashes, no soda. (10.) 



During the digestive process, therefore, 

 the soda of the bile, and, along with it, all 

 the soluble parts of that fluid, are returned 

 into the circulation. This soda re-appears 

 in ihe newly-formed blood, and, finally, we 

 find it in the urine in the form of phosphate, 

 carbonate, and hippurate of soda. Berzelius 

 found in 1,000 parts of fresh human faeces 

 only nine parts of substance similar to bile ; 

 5 ounces, therefore, would contain only 21 

 grains of dried bile, equivalent to 219 grains 

 of fresh bile. But a man secretes daily 

 from 9,640 to 11,520 grains of fluid bile, 

 that is, from 45 to 56 times as much as can 

 be detected in the matters discharged by the 

 intestinal canal. 



Whatever opinion we may entertain of 



I the accuracy of the physiological experi- 

 ments, in regard to the quantity of bile se- 

 creted by the different classes of animals; 

 thus much is certain, that even the maxi- 

 mum of supposed secretion, in man and in 

 the horse, does not contain as much carbon 

 as is given out in respiration. With all the 

 fat which is mixed with it, or enters into its 

 composition, dried bile does not contain 

 more than 69 per cent, of carbon. Conse- 

 quently, if a horse secretes 57 Ibs. of bile, 

 this quantity will contain only 40 ounces of 

 carbon. But the horse expires daily nearly 

 twice as much in the form of carbonic acid. 

 A precisely similar proportion holds good in 

 man. 



Along with the matter destined for the 

 formation or reproduction of organs, the cir- 

 culation conveys oxygen to all parts of the 

 body. Now, into whatever combination the 

 oxygen may enter in the blood, it must be 

 held as certain, that such of the constituents 

 of blood as are employed for reproduction, 

 are not materially altered by it. In muscular 

 fibre we find fibrine, with all the properties 

 it had in venous blood ; the albumen in the 

 blood does not combine with oxygen. The 

 oxygen may possibly serve to convert into 

 the gaseous state some unknown constituent 

 of the blood; but those well-known con- 

 stituents, which are employed in reproduc- 

 tion, cannot be destined to support the respi- 

 ratory process ; none of their properties can 

 justify such an opinion. 



Without attempting in this place to ex- 

 haust the whole question of the share taken 

 by the bile in the vital operations, it follows, 

 as has been observed, from the simple com- 

 parison of those parts of the food of the car- 

 nivora which are capable of assimilation, 

 with the ultimate products into which it is 

 converted, that all the carbon of the food, 

 except that portion which is found in the 

 urine, is given out as carbonic acid. 



But this carbon was ultimately derived 

 from the substance of the metamorphosed 

 tissues ; and this being admitted, the ques- 

 tion of the necessity of substances contain- 

 ing much carbon and no nitrogen in the food 

 of the young of the carnivora, and in that 

 of the graminivora, is resolved in a strikingly 

 simple manner. 



XII. It cannot be disputed that in an 

 adult carnivorous animal, which neither 

 gains nor loses weight perceptibly from day 

 to day, its nourishment, the waste of organ- 

 ized tissue, and its consumption of oxygen* 

 stand to each other in a well-defined and! 

 fixed relation. 



The carbon of the carbonic acid given off, 

 with that of the urine ; the nitrogen of the 

 urine, and the hydrogen given off as am- 

 monia and water; these elements, taken 

 together, must be exactly equal in weight to 

 the carbon, nitrogen, and hydrogen of the 

 metamorphosed tissues, and since these last 

 are exactly replaced by the food, to the car- 

 bon, nitrogen, and hydrogen of Uie food. 

 Were this not the case, the weight of the 



