BILE IN THE HUMAN BODY. 



53 



without an abundant supply of potash, the 

 production of milk becomes impossible. 



67. All observation leads, as appears from 

 the preceding exposition, to the opinion, 

 that certain non-azotized constituents of the 

 food of the herbivora (starch, sugar, gum, 

 &c.,) acquire the form of a compound of 

 soda, which, in their bodies, serves for the 

 same purpose as that which we know cer- 

 tainly to be served by the bile (the most 

 highly carbonized product of the trans- 

 formation of their tissues) in the bodies of 

 the carnivora. These substances are em- 

 ployed to support certain vital actions, and 

 are finally consumed in the generation of 

 animal heat, and in furnishing means of re- 

 sistance to the action of the atmosphere. In 

 the carnivora, the rapid transformation of 

 their tissues is a condition of their existence, 

 because it is only as the result of the change 

 of matter in the body that those substances 

 can be formed, which are destined to enter 

 into combination with the oxygen of the air ; 

 and in this sense we may say that the non- 

 azotized constituents of the food of the 

 herbivora impede the change of matter, or 

 retard it, and render unnecessary, at all 

 events, so rapid a process as occurs in the 

 carnivora. 



68. The quantity of azotized matter, pro- 

 portionally so small, which the herbivora 

 require to support their vital functions, is 

 closely connected with the power possessed 

 by the non-azotized parts of their food to 

 act as means of supporting the respiratory 

 process; and this consideration seems to ren- 

 der it not improbable, that the necessity for 

 more complex organs of digestion in the her- 

 bivora is rather owing to the difficulty of 

 rendering soluble and available for the vital 

 processes certain non-azotized compounds 

 (gum? amylaceous fibre?) than to any 

 thing in the change or transformation of 

 vegetable fibrine, albumen and caseine into 

 blood ; since, for this latter purpose, the less 

 complex digestive apparatus of the carnivora 

 is amply sufficient. 



69. If, in man, when fed on a mixed diet, 

 starch perform a similar part to that which it 

 plays in the body of the herbivora ; if it be 

 assumed that the elements of starch are 

 equally necessary to the formation of the 

 bile in man as in these animals; then it 

 follows that a part of the azotized products 

 of the transformation of the tissues in the 

 human body, before they are expelled 

 through the bladder, returns into the circu- 

 lation from the liver in the shape of bile, 

 and is separated by the kidneys from the 

 blood, as the ultimate product of the re- 

 spiratory process. 



70. When there is a deficiency of non- 

 azotized matter in the food of man, this 

 form of the production of bile is rendered 

 impossible. In that case, the secretions : 

 must possess a different composition ; and f 

 the appearance of uric acid in the urine, the I 

 deposition of uric acid in the joints and in | 

 the bladder, as well as the influence which 



an excess of animal food (which must be 

 considered equivalent to a deficiency of 

 starch, &c.,) exercises on the separation of 

 uric acid in certain individuals, may be ex- 

 plained on this principle. If starch, sugar, 

 &.C., be deficient, then a part of the azotized 

 compounds formed during the change of 

 matter will either remain in the situation 

 where they have been formed, in which case 

 they will be sent from the liver in the circu- 

 lation, and therefore will not undergo the 

 final changes dependent on the action of 

 oxygen ; or they will be separated by the 

 kidneys in some form different from the 

 normal one. 



71. In the preceding paragraphs I have 

 endeavoured to prove that the non-azotized 

 constituents of food exercise a most decided 

 influence on the nature and quality of the 

 animal secretions. Whether this occur di- 

 rectly ; whether, that is to say, their elements 

 take an immediate share in the act of trans- 

 formation of tissues ; or whether their share 

 in that process be an indirect one, is a ques- 

 tion probably capable of being resolved by 

 careful and cautious experiment and observ- 

 ation. It is possible, that the non-azotized 

 constituents of food, after undergoing some 

 change, are carried from the intestinal canal 

 directly to the liver, and that they are con- 

 verted into bile in this organ, where they 

 meet with the products of the metamor- 

 phosed tissues, and subsequently complete 

 their course through the circulation. 



This opinion appears more probable, when 

 we reflect that as yet no trace of starch or 

 sugar has been detected in arterial blood, 

 not even in animals which had been fed ex- 

 clusively with these substances. We cannot 

 ascribe to these substances, since they are 

 wanting in arterial blood, any share in the 

 nutritive process ; and the occurrence of 

 sugar in the urine of those affected with dia- 

 betes mellitus (which sugar, according to 

 the best observations, is derived from the 

 food) coupled with its total absence in the 

 blood of the same patients, obviously proves 

 that starch and sugar are not, as such, taken 

 into the circulation. 



72. The writings of physiologists contain 

 many proofs of the presence of certain con- 

 stituents of the bile in the blood of man in a 

 state of health, although their quantity can 

 hardly be determined. Indeed, if we sup- 

 pose 8J Ibs. (58,000 grs.) of blood to pass 

 through the liver every minute, and if from 

 this quantity of blood 2 drops of bile (3 

 grains to the drop) are secreted, this would 

 amount to Tvfath P art of the weight of the 

 blood, a proportion far too small to be quan- 

 titatively ascertained by analysis. 



73. The greater part of the bile in the body 

 of the herbivora, and in that of man fed on 

 mixed food, appears from the preceding con- 

 siderations to be derived from the elements 

 of the non-azotized food. But its formation 

 is impossible without the addition of an 

 azotized body, for the bile is a compound of 

 nitrogen. All varieties of bile yet examined, 



