166 MANUAL OF CATTLE-FEEBIN^a 



protecting it from destruction. Tliat tliis is so is perliaps 

 indicated by the fact that a gain of sulphur also took place. 

 All the albuminoids contain this element, while asparagin 

 is free from it, and hence we may conclude that the pio- 

 tein deposited in the body was derived fi'om the albu- 

 minoids of the food, and was not formed by a synthetical 

 process from the asparagin. 



An important point is that the gain produced by as- 

 paragin was nearly as great as that produced by an equiva- 

 lent amount of albuminoids. From this it would appear 

 that while asparagin cannot alone supply material for the 

 formation of protein in the body, it is fully capable of 

 performing the functions of the so-called circulatory pro- 

 tein, so far as the production of flesh is concerned, and for 

 this purpose is practically just as valuable as protein for 

 increasing the richness of a ration already containing a 

 reasonable amount of that substance. This suggests the 

 question whether much of the so-called circulatory protein 

 of the body may not be simply that portion of the protein 

 of the food which is converted into amides by the action 

 of trypsin and other ferments during digestion. The sup 

 position seems quite plausible, and is certainly interesting 

 from a physiological standpoint, though of little practical 

 importance for the purposes of cattle-feeding. 



Other Amides.— Whether what "Weiske has shown re- 

 garding asparagin is true of other amides as well, can, of 

 course, be finally decided only by direct experiment ; but 

 in the meantime, while we must beware of drawing too 

 general conclusions from a single experiment, it seems 

 highly probable that at least those other amides which 

 have been shown to bo convertible into urea in the body 

 may contribute to nourish it. 



But, if this be true, it also follows that these bodies as 



