446 NUTRITION. 



by which probably the greatest advances have been made ; it con- 

 sists in the attempt to determine the amount of that motion which 

 impels a very considerable fraction of the animal juices towards 

 the intestinal canal. From the statements which have been pre- 

 viously made regarding the quantitative relations of the digestive 

 fluids it appears, that according to Bidder and Schmidt's investi- 

 gations and calculations, an adult man weighing about 64 kilo- 

 grammes [or 10 stone"] secretes in twenty-four hours about 1600 

 grammes of saliva, in which are 15 grammes of solid matters, 1600 

 grammes of bile containing 80 grammes of solid matters, 6400 

 grammes of gastric juice with 192 grammes of solid matters, 200 

 grammes of pancreatic fluid with 20 grammes of solid constituents, 

 and 200 grammes of intestinal juice with 3 grammes of non-volatile 

 matters; consequently there are in twenty-four hours 10000 grammes 

 of juices, containing 9690 grammes of water and 310 of solid sub- 

 stances, which pass from the blood into the intestinal canal, from 

 which they are again for the most part resorbed. Since the body 

 of a man weighing 64 kilogrammes contains about 20 kilogrammes 

 [or 44 Ibs."] of solid matters, and 44 kilogrammes [nearly 97 Ibs.] 

 of water, it follows that from l-5th to l-4th of the latter would be 

 brought into the intestinal canal in the course of twenty-four hours, 

 but only from l-70th to l-60th of the former. The coincidence 

 between the amount of solid constituents in this collective sum of 

 the digestive fluids and in the lymph (according to Marchand's 

 determination), namely 3 *!--, is a point of much interest. Since 

 very careful analyses of the digestive fluids, as well as determina- 

 tions of their amounts, were instituted by Schmidt, it is easy to see 

 that we may obtain the most decisive conclusions from these 

 numerically-established points, regarding the relative amount of 

 this metamorphosis of matter within the body, as well in reference 

 to the individual organic matters as to the elements in general. We 

 may notice, as especially important in this point of view, the rela- 

 tions which have been established by these investigations between 

 the biliary secretion and the respiration, and between the former 

 and the urinary secretion. Thus, for instance, a dog for each kilo- 

 gramme's weight consumes in twenty-four hours 8*6grammes of car- 

 bon, while in the same time it excretes 1 gramme of biliary matter ; 

 0*5 of a gramme of carbon of this biliary matter returns from the 

 intestine into the blood hence it follows, that from 5 to 6j of 

 the expired carbon has to go through the stage of bile-formation. 

 This proportion is not essentially affected during a flesh-diet; but 

 is altered by the use of highly amylaceous food, when the amount 



