Report of the Assistant Chemist.* 
AN EXAMINATION OF FEEDING-STUFFS. 
During the past year my work, aside from the routine 
work incidental to the Station, has been mainly a continu- 
ation of the examination of our feeding-stuffs—their chem- 
ical composition and relative digestibility. When these are 
more fully studied it is hoped that some attention may be 
given to their physiological effects ; but before this_can be 
satisfactorily done there is a necessity for a better knowl- 
edge of the work in hand and a means of measuring the 
relative digestibility of the other constituents of the feed— 
fat and nitrogen-free extract. Considerable time has been 
given to working out methods whereby this can be done. 
For measuring the digestible fat a process of saponification 
promised much with the coarse fodders, but with meal and 
similar products the difficulty of filtering has prevented its 
use, although it is hoped this may finally be over- 
come and thus a means found which will serve the purpose. 
With nitrogen-free extract an attempt has been made to 
measure its digestibility by diastatic fermentation. 
The few experiments which time has permitted me to 
make in this direction, has offered so much of encourage- 
ment that the method will be further tested. 
The processes pursued in the digestion of the albuminoids 
are the same as given in the last report, except that one 
gram of the substance is always used, as it can be worked 
to better advantage and is preferable to a larger quantity. 
In order to test what effect, in the digestion, each separate 
part of the digestion fluid has, a few experiments were 
made, also with different quantities of the fluid as com- 
monly used. Water alone, water and HCl. as in regular 
digestion, water and pepsin, no HCl., different amounts of 
digestion fluid, and a digestion fluid containing twice the 
usual amount of pepsin, were used. 


*K. KF. Ladd. 
