166 STARCH, ETC. ASSIST IN FORMING 



since, for tliis latter purpose, the less complex di- 

 gestive apjDaratus of the carnivora is amply suffi- 

 cient. 



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 for- 

 mation of the bile in man as in these animals ; then 

 it follows that a part of the azotised products of the 

 transformation of the tissues in the human body, 

 before they are expelled through the bladder, re- 

 turns into the circulation from the liver in the shape 

 of bile, and is separated by the kidneys from the 

 blood, as the ultimate product of the respiratory 

 process. 



70. When there is a deficiency of non-azotised 

 matter in the food of man, this form of the produc- 

 tion of bile is rendered impossible. In that case, 

 the secretions must possess a different composition ; 

 and the appearance of uric acid in the urine, the 

 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 separa- 

 tion of uric acid in certain individuals, may be 

 explained on this principle. If starch, sugar, &c., 

 be deficient, then a part of the azotised compounds 

 formed during the change of matter will either 

 remain in the situation where they have been 

 formed, in which case they will not be sent from 



