MAHUAL OP CACTLE-FEEDIJS^G. 



161 



Such experiments as tliis, liowever, are not adapted, ab 

 tliej were not intended, to show the nutritive effect of the 

 substance experimented on. 



"We have seen that in the dog the addition of protein to 

 the previous food causes but a temporary gain of flesh, 

 while tlie " protein consumption " is permanently increased, 

 and we should expect that, if amides aided in any way the 

 production of flesh, the effect of a sudden addition of them 

 to the food would be much the same. In an experiment 

 continued for so short a time as this was, the nutritive effect 

 must of necessity be transitory and hard to isolate. At the 

 same time, the above results do not negative the belief that 

 amides are of value as food. 



The experiment with leuein gave essentially the same 

 results m the one on glj^eoeoL The leuein was prepared 

 f mm horn, and was not perfectly pure or dry. 



Date. 



Pood. 



October 4 ' Bread, milk, and water. 



Ci 



Same, + 10 grms. leucm. 

 Bread, milk, and water. 



Urea per day 

 Grms. 





Li 



ti 



it, 



u 



5.045 

 660 

 9 098 

 4 380' 

 3 9S6 



The average excretion of urea for the days preceding 



the feeding with leuein was 4.585 gi-ammes per day. 



Total urea on 6tli and Tth 15.758 grammes 



TJrea of two average days 0. 170 '* 



Excess caused by 40 grammes leuein 6.588 " 



Uiea equivalent to " ** " 9.000 ** 



Difference (=26 8 per cent ) , . . . 2,413 " 



