Jan. io, 1916 
Mature Beef and Immature Veal 
669 
EXPERIMENTAL WORK 
MATERIALS 
At convenient intervals a live calf, 7 days old or less, was obtained 
from a veterinarian in Washington, D. C., who procured the supply 
from farms near by. Forty-one calves were procured in this way. On 
12 of these animals quantitative data were obtained; the rest of the 
material was used in the feeding experiments with cats. Each calf was 
inspected by a member of the staff of the Pathological Division. In 
every case, except veal sample 7, the calf purchased was found to be in 
good condition. 
Immediately after the calf was killed, dressed, and quartered, the meat 
was trimmed from the bones. When the calf was intended for quanti¬ 
tative analytic work and for digestion experiments, care was taken to 
remove the muscles entire or nearly entire, so as to exclude bits of bone, 
tendon, etc. The whole muscles, free from adherent fat and the tough, 
tendinous ends, were placed in a wide-mouth 8-liter glass-stoppered 
bottle and kept in cold storage at or very near i° C. (34 0 F.) until used. 
When the calf was intended for feeding to the experimental cats, the 
meat was trimmed less carefully, so that adherent fat, small pieces of 
soft bone, etc., were included in the material stored. To this were 
added the liver, kidneys, spleen, lungs, and heart, all of which the cats 
received in their food (see p. 705). About 10 kgm. of muscle were 
obtained from each calf. A detailed record was made of the dates on 
which the calves were killed, etc., so that the age of the meat when used 
for the various purposes was always known. 
Along with the analyses and digestions made on the veal, control deter¬ 
minations were made on beef. The greatest care was taken throughout 
the entire work to be certain that the data on beef and veal were obtained 
under identical conditions. Whenever a calf was killed and the veal 
was intended for comparative work with beef, 10 pounds of ordinary 
lean beef round steak were purchased in a market near by. No inquiries 
were made regarding the beef; it represented so much lean beef pur¬ 
chased at random. Soon after being brought to the laboratory the 
beef was carefully trimmed—i. e., fat and connective tissue were removed, 
leaving only the lean muscle tissue, with a few small specks of fat here 
and there. This was transferred to an 8-liter glass-stoppered wide- 
mouth bottle and kept until used in cold storage alongside the bottle 
containing the veal. The beef was numbered to correspond with the 
veal—i. e., beef sample 8 was the beef used for control work on veal 
sample 8. 
Sometimes the comparative analyses and digestions were begun on 
veal and beef 1 day old—i. e., 1 day in storage—although the beef was 
really mature beef of unknown age. In some experiments the meats were 
