278 DIGESTION. 



the excrements, 914*8 grammes of this substance, or 1016'4 

 grammes of sugar, must have been resorbed. 



The horse C took 1871*8 grammes of starch on the last day of 

 the experiment, and 413'2 grammes were found in the excrements; 

 hence 1458*6 grammes of starch, or 1620-6 of sugar, must have been 

 absorbed into the mass of the juices. 



Hence in these animals, if the starch was converted solely into 

 sugar, 1382 grammes of sugar were, on an average, formed in 24 

 hours, and transmitted into the blood-vessels and lacteals. As the 

 animals were fed at short intervals of 2 hours, we may assume that 

 57*58 grammes passed into the chyle or into the portal blood in 1 

 hour, and consequently nearly 1 gramme in 1 minute. Now the 

 movement of the fluid is not so rapid either in the lacteals or in the 

 portal vein as to lead to the belief that the absorbed sugar is too 

 quickly removed from the neighbourhood of the intestine, or 

 from the abdomen generally, to admit of this substance being 

 qualitatively, if not quantitatively, determined in one of these 

 fluids. 



It has been formerly mentioned that it was only sometimes 

 that I could obtain even traces of sugar in the portal blood of 

 horses, there often being no indication of this substance. If pre- 

 vious observers believed that they had detected sugar in the blood 

 of this vessel, and found that the properties of this fluid generally 

 were different from those which I have described, the reason of 

 these discrepancies is very probably to be sought in the methods 

 of obtaining the portal blood. The proper method of proceeding is 

 not at first to lay open the whole abdomen, and then to make a 

 regular dissection of the portal vein; for the blood of the 

 hepatic veins in this case regurgitates, and a portion of it makes 

 its way into the branches of the portal vein ; and as the hepatic 

 blood presents peculiarities in 'its morphological elements, and con- 

 tains sugar, the experiment must be more or less marred. We 

 should make only a small opening in the abdominal walls, and 

 reaching the portal vein as speedily as possible, we should tie it 

 at the point where it enters the liver. Even Bernard,* when he 

 collected portal blood in this manner, never found a trace of sugar 

 in it. In procuring the portal blood of the horses in these experi- 

 ments, I guarded against the above-named source of error, and I 

 never found sugar or even a trace of dextrin in it. 



Although I have often previously stated the procedure which I 

 adopt for the recognition of sugar, yet I would here remark, in 

 * Nouvelle fonctiou du foie, &c. Paris, 1853, p. 23. 



