678 
Journal of Agricultural Research 
Vol. V, No. is 
Table IV. — Percentage of amino nitrogen in extractive nitrogen in beef and veal 
Sample No. 
Experi¬ 
ment No. 
Beef. 
Veal. 
8. 
26 
Per cent. 
27 
Per cent. 
18 
8. 
25 
27 
18 
9 . 
27 
a Co 
II 
10. 
30 
22 
19 
10. 
31 
24 
24 
Sample No. 
Experi¬ 
ment No. 
Beef. 
Veal. 
Per cent. 
Per cent. 
II. 
32 
19 
16 
12. 
34 
23 
*9 
Average. 
24 
18 
a Figure for skim-milk sample 2; not included in the average (see p. 695). 
The figures for the percentage of amino nitrogen in Table IV were 
obtained by single determinations on each filtrate. Duplicates on veal 
sample io and skim-milk sample 2 agreed almost exactly, which is to 
be expected when small volumes of nitrogen gas are obtained in this 
determination. This, together with the comparatively large blank on 
the reagents, makes the experimental error in these determinations 
higher than in others. Nevertheless the data have been obtained on 
five different calves and their control samples of beef, and the uniformly 
higher amino-nitrogen content in the beef extractives is probably a cor¬ 
rect indication of a slight difference between the beef and veal. The 
significance of this difference, if any, requires further work for its eluci¬ 
dation. 
DISTRIBUTION OF NITROGEN IN BEEF AND VEAL HYDROLYZED BY HYDROCHLORIC 
ACID 
Hydrolysis. —The beef and veal were hydrolyzed by boiling with 
hydrochloric acid in 300 c. c. Jena glass Erlenmeyer flasks provided 
with ground-in condenser tubes 100 cm. in length. Into a weighed flask 
25 gm. of meat were weighed quickly to the nearest 0.1 gm. and the exact 
weight noted. Two such portions of beef and two of veal were weighed 
from large samples of the meats freshly hashed for several determina¬ 
tions. To each flask 175 c. c. of hydrochloric acid (1 :1) were added. 
The ratio is 35 parts of 20 per cent hydrochloric acid to 1 of pro¬ 
tein, found by Van Slyke (1912, p. 296) to hydrolyze proteins completely 
after boiling for 24 hours. In all the experiments except the first with 
beef and veal sample 8 the hydrolytic mixture was boiled for 24 hours. 
Beef and veal samples 8 were boiled for 24 and 48 hours, but no differ¬ 
ences in the results were found. A small piece of broken glass added to 
the material in the flask prevented bumping. After boiling the required 
length of time the mixtures were cooled, transferred to 250 c. c. volu¬ 
metric flasks, and diluted to the mark. Portions of these mixtures 
were used in the following determinations. 
Total nitrogen. —From each of the four flasks 25 c. c. portions of 
the mixture, corresponding very nearly to 2.5 gm. of meat, were pipetted 
into Kjeldahl flasks and the total nitrogen determined. The results 
obtained in this way on beef and veal samples 8 to 12 have been given 
in Table I. 
