ORIGIN OF THE BILE. 



47 



which should most powerfully excite our 

 wonder and admiration. 



Gelatinous tissue is formed from blood, 

 from compounds of proteine. It may be 

 produced by the addition, to the elements of 

 proteine, of allantoine and water, or of wa- 

 ter, urea, and uric acid ; or by the separation 

 from the elements of proteine of a com- 

 pound containing no nitrogen. The solution 

 of such problems becomes less difficult, 

 when the problem to be solved, the question 

 to be answered, is matured and clearly put. 

 Every experimental decision of any such 

 question in the negative forms the starting- 

 point of a new question, the solution of 

 which, when obtained, is the necessary 

 consequence of our having put the first 

 question. 



40. In the foregoing sections, no other 

 constituent of the bile, besides choleic acid, 

 has been brought into the calculation ; be- 

 cause it alone is known with certainty to 

 contain nitrogen. Now, if it be admitted 

 that its nitrogen is derived from the meta- 

 morphosed tissues, it is not improbable that 

 the carbon, and other elements which it con- 

 tains, are derived from the same source. 



There cannot be the smallest doubt, that 

 in the carnivora, the constituents of the 

 urine and the bile are derived from the trans- 

 formation of compounds of proteine ; for, 

 except fat, they consume no food but such 

 as contains proteine, or has been formed 

 from that substance. Their food is identical 

 with their blood ; and it is a matter of in- 

 difference which of the two we select as the 

 starting-point of the chemical developement 

 of the vital metamorphoses. 



There can be no greater contradiction, 

 with regard to the nutritive process, than to 

 suppose that the nitrogen of the food can 

 pass into the urine as urea, without having 

 previously become part of an organized tis- 

 sue; for albumen, the only constituent of 

 blood, which, from its amount, ought to be 

 taken into consideration, suffers not the 

 slightest change in passing thro ugh the liver 

 or kidneys ; we find it in every part of the 

 body with the same appearance and the 

 same properties. These organs cannot be 

 adapted for the alteration or decomposition 

 of the substance from which all the other 

 organs of the body are to be formed. 



41. From the characters of chyle and 

 lymph, it appears with certainty that the 

 soluble parts of the food or of the chyme 

 acquire the form of albumen. Hard-boiled 

 white of egg, boiled or coagulated fibrine, 

 which have again become soluble in the 

 stomach, but have lost their coagulability by 

 the action of air or heat, recover these pro- 

 perties by degrees. In the chyle, the acid 

 reaction of the chyme has already passed 

 into the weak alkaline reaction of the blood ; 

 and the chyle, when, after passing through 

 the mesenteric glands, it has reached the tho- 

 racic duet, contains albumen coagulable by 

 heat ; and, when left to itself, deposits fibrine. 

 All the compounds of proteine, absorbed dur- 



| ing the passage of the chyme through the 

 intestinal canal, take the form of albumen, 

 which, as the results of incubation in the 

 fowl's egg testify, contains the fundamental 

 elements of all organized tissues, with the 

 exception of iron, which is obtained from 

 other sources. 



Practical medicine has long ago answered 

 the question, what becomes in man of the 

 compounds of proteine taken in excess, 

 what change is undergone by the supera- 

 bundant nitrogenized food? The blood-ves- 

 sels are distended with excess of blood, the 

 other vessels with excess of their fluids, and 

 if the too great supply of food be kept up, 

 and the blood, or other fluids adapted for 

 forming blood, be not applied to their natu- 

 ral purposes, if the soluble matters be not 

 taken up by the proper organs, various gases 

 are disengaged, as in processes of putrefac- 

 faction, the excrements assume an altered 

 quality in colour, smell, &,c. Should the 

 fluids in the absorbent and lymphatic ves 

 sels undergo a similar decomposition, this is 

 immediately visible in the blood, and the 

 nutritive process then assumes new forms. 



42. No one of all these appearances should 

 occur, if the liver and kidneys were capable 

 of effecting the resolution of the superabun 

 dant compounds of proteine into urea, uric 

 acid, and bile. All the observations which 

 have been made in reference to the influence, 

 of nitrogenized food on the composition of 

 the urine have failed entirely to demonstrate 

 the existence of any direct influence of the 

 kind ; for 'he phenomena are susceptible of 

 another and a far more simple interpretation, 

 if, along with the food, we consider the 

 mode of life and habits of the individuals 

 who have been the subjects of investigation. 

 Gravel and calculus occur in persons who 

 use very little animal food. Concretions of 

 uric acid have never yet been observed in 

 carnivorous mammalia, living in the wild 

 state,* and among nations which live entirely 

 on flesh, deposits of uric acid concretions in 

 the limbs or in the bladder are utterly un- 

 knoAvn. 



43. That which must be viewed as an 

 undeniable truth in regard to the origin of 

 the bile, or, more accurately speaking, of 

 choleic acid in the carnivora, cannot hold in 

 regard to all the constituents of the bile se- 

 creted by the liver in the herbivora, for with 

 the enormous quantity of bile produced, for 

 example, by the liver of an ox, it is abso- 

 lutely impossible to suppose that all its car- 

 bon is derived from the metamorphosed 

 tissues. 



Assuming the 59 oz. of dry bile (from 37 

 Ibs. of fresh bile secreted by an ox) to con- 

 tain the same per centage of nitrogen as cho- 

 leic acid, (3'86per cent.,) this would amount 

 to nearly 2^- oz. of nitrogen; and if this ni- 



* The occurrence of urate of ammonia in a con* 

 cretion found in a dog, which was examined by 

 I Lassaigne, is to be doubted, unless Lassaigne ex- 

 I tracted it himself from the bladder of the animal. 



