BILE IN THE HUMAN BODY. 159 



possible, that the non-azotized constituents of food, 

 after undergoing some change, are carried from the in- 

 testinal canal directly to the liver, and that they are 

 converted into bile in this organ, where they meet with 

 the products of the metamorphosed tissues, and subse- 

 quently 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 exclusively with these substances. We cannot as- 

 cribe 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 diabetes 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. 



71. The writings of physiologists contain many 

 proofs of the presence of certain constituents of the 

 bile in the blood of man in a state of health, although 

 their quantity can hardly be determined. Indeed, if we 

 suppose 8|lbs. (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 ^th part of the weight of the blood, 

 a proportion far too small to be quantitatively ascer- 

 tained by analysis. 



72. The greater part of the bile in the body of the 

 herbivora, and in that of man fed on mixed food, ap- 



