692 
Journal of Agricultural Research 
Vol. V, No. is 
r 
as in the experiments in Table IX. By comparing the results of experiment 13 with 
those of experiment 14, for example, it will be apparent that the undigested residues 
in experiment 13 give an imperfect idea of the amount of indigestible protein present 
in beef and veal; according to the data of Table IX practically all of the nitrogen was 
in soluble form at the end of 24 hours. 
The conditions of the experiments in Table IX were as follows: In each experiment 
the digestion mixture consisted of 100 gm. of meat plus 2,000 c. c. of 0.2 per cent 
hydrochloric acid plus 200 mgm. of pepsin 1. For nitrogen determinations 100 c.c. 
of digestion fluid, equivalent to approximately 5 gm. of meat, were used. 
Tabi^ IX .—Rate of formation of proteoses and peptones in pepsin hydrochloric-acid 
solution 
QUANTITY (in CUBIC CENTIMETERS) OR N/$ PROTEOSE AND PEPTONE NITROGEN 
Experiment No. — 
Digestion period. 
17 . 
19 
21 
23 
Beef 
sample 
3 - 
Veal 
sample 
3 - 
Beef 
sample 
5 - 
Veal 
sample 
5 - 
Skim 
milk 
sample 
1. 
Veal 
sample 
5 - 
Beef 
sample 
6 . 
Veal 
sample 
6 . 
Beef 
sample 
7 - 
Veal 
sample 
7 - 
Hours. 
1 . 
2 . 
15.8 
24. 7 
IO. 3 
20. 5 
1 5-6 
26.8 
16. 8 
26.6 
27.7 
37 * 2 
12. 6 
2 3 - 4 
IS -7 
23-4 
12. I 
19-3 
17.1 
27.9 
11. 6 
18.5 
4 . 
33 - 8 
3 1 * 1 
37 - 8 
36.3 
43 - 8 
34-6 
33 - i 
29. 6 
37-9 
29. O 
7 . 
41. 8 
39 -S 
45-3 
41.4 
46. 2 
41. O 
41. O 
37 - 8 
44. 2 
36. 7 
24. 
5 °- 7 
47 . I 
5 2 - 3 
46. 7 
50-4 
46. 6 
52.8 
(a) 
5 2 -9 
45 - 5 
Theoretical 
maximum 
51.8 
4 8 -3 
53 - 1 
48. 0 
54 - 8 
48. 0 
53 -S 
43 - 8 
54-2 
47-3 
Extractiv e 
nitrogen.. 
7 - S 
8.9 
7-2 
7 . s 
3 - 7 
7.8 
8. 1 
7- 7 
7- 5 
11. 1 
Pepsin ni¬ 
trogen. . . 
• 5 
• 5 
* 5 
• 5 
• 5 
•S 
• 5 
• 5 
•5 
• 5 
QUANTITY (IN CUBIC CENTIMETERS) OP N IS ACID PROTEINATE NITROGEN 
Hours. 
I. 
2. 7 
i -5 
4. 6 
4. 2 
26. 0 
2.4 
2.8 
. 1. 6 
3-3 
i- 5 
2 .. 
3 - 9 
2.8 
4.8 
4-9 
17-3 
4-5 
4 - 7 
3-2 
5 - 2 
3 - 7 
4 . 
3-4 
3-6 
5 -o 
4. 6 
10. 8 
4.6 
5-4 
4*3 
4.9 
4. 0 
7 . 
3-3 
4-3 
3-8 
5 - 1 
8. 2 
5*6 
5-2 
5-9 
4. 1 
4. 2 
24.. 
3 -o 
4. 0 
3-3 
4. 2 
4-3 
4*9 
3 - 7 
4 - 5 
2. 7 
4. 0 
Age of meat, 
days. 
8 : 
8 
0 
0 
18 
18 
*3 
13 
3 
3 
a Determination lost. Result obtained at 53 hours (47.1 c. c.) is probably incorrect, being larger than the 
theoretical maximum for that mixture. 
The results of the experiments in Table IX can be plotted, and curves, of which 
the following are typical, obtained (fig. 1). 
After several comparisons of veal with beef showed no appreciable differences 
between the two as regards their behavior in pepsin hydrochloric acid or in trypsin 
sodium carbonate, it was desirable to compare the veal with some other protein 
material in order to be certain that the method used would detect a difference in the 
