MANUAL OF CArrLK-FEEmNG. 159 



hn>ve since been shown to contain not inconsiderable 

 amounts of tliese bodies. 



If, as some writers have assumed, tliey have no nutri- 

 tive value, we must conclude that our domestic animals 

 require considerably less true protein in their food than 

 has been hitherto thought, while if they have a value in 

 feeding, it is important to know what it is. We shall con- 

 fine our attention here to the amides, since these are the 

 only non-albuminoid nitrogenous matters which have been 

 experimented on, and the only ones which have yet been 

 found abundantly in the common feeding-stuffs. 



It may safely be assumed that these comparatively sim- 

 ple bodies cannot perform all the functions of the albumin- 

 oids, but it would seem tliat certain authors have allowed 

 themselves to be carried too far by purely speculative con- 

 siderations when they have pronounced them valuelesa for 

 animal nutrition. 



Amides are Deeomposed in the Body. — It has been 

 shown by several investigators that amides introduced into 

 the stomach are resorbed, and take part in the chemical 

 changes m the body. Schultzen & Kencld^ ^PP^^^ ^^ 

 have been the first to experiment in this direction. They 

 fed a dog, weighing about 16 lbs., with a fixed amount of 

 bread, milk, and water until equilibrium was established 

 between the supply and excretion of nitrogen, and then 

 added to the food various amides. They experimented on 

 acetamide, glycocol, leucin, and tyrosin, and found that all 

 except the first produced a decided increase in the excretion 

 of urea. Acetamide appeared to pass through the system 

 unaltered. 



With glycocol the following results were obtained : 



♦ »? 



Zeitschrift fur Biologie, VIII , 134 



