Jan. io, 1916 
Mature Beef and Immature Veal 
677 
Many investigations have been made on the behavior of beef when 
frozen, but such results are not exactly comparable with those obtained 
by the foregoing investigators nor by the writer on beef stored at or near 
2 0 C. 
It is obvious that the beef and veal used in this work underwent pro¬ 
teolysis during the storage periods to practically the same extent. The 
changes that took place in the beef are entirely comparable with those 
observed by others in beef stored under similar conditions. The slightly 
higher average content of extractive nitrogen in the veal (Table III) is 
not regarded as physiologically significant in the present consideration 
of the fitness of 1-week-old veal as food. The extractives of immature 
veal are the same as those of mature beef (Lindsay, 1911), and 
the sEght quantitative difference found between the 10 “bob-veal” 
calves and their corresponding 10 samples of lean beef (summarized in 
Table III) do not warrant the inference that the tissues of the very young 
calf are loaded with unexcreted nitrogenous waste products. 
AMINO NITROGEN IN MEAT EXTRACTIVES 
The hot-water extracts of beef and veal used for the determination of 
extractive nitrogen were also used for the determination of amino nitro¬ 
gen in the nitrogenous extractives present. The figures* obtained were 
used as blanks in those digestion experiments in which the rate of diges¬ 
tion was measured by the rate of formation of amino nitrogen (see 
p. 696). Any marked differences between the figures for beef and those 
for veal might have led to the detection of significant differences in 
their composition. 
Ten c. c. of filtrate, containing the extractives from not quite 0.5 gm. 
of beef or veal, were introduced into the Van Slyke amino-nitrogen 
apparatus and the amino nitrogen determined exactly as it was deter¬ 
mined in the digestion experiments (see p. 680). The volume of gas 
measured was small, ranging from 1.9 to 5 c. c. The weight of nitrogen 
so obtained was calculated to 1 gm. of fresh meat, and this figure was 
divided by the weight of extractive nitrogen in 1 gm. of meat. The 
results are summarized in Table IV. In experiment 27 the digestibility 
of veal sample 9 was compared with that of skim milk inste'ad of beef. The 
amino-nitrogen determination on skim-milk sample 2 was made on 10 c. c. 
of diluted skim milk containing 600 gm, of skim milk diluted to 1,000 c. c. 
which was used for other determinations (see p. 695). In this case the 
amino nitrogen was derived not only from the nonprotein extractives but 
from the proteins as well. The amino nitrogen obtained was calculated 
to 1 gm. of skim milk, and this figure was divided by the weight of extrac¬ 
tive nitrogen found in 1 gm. of skim milk by the method described 
on p. 695. 
