104 REPORT OF THE CHEMIST OF THE 
of nitrogen with 80 cc. of water. The bottles and contents were 
heated to 212° F. (100° C.) for 15 minutes to destroy all enzymes 
and organisms. After cooling, there were added to each bottle 
3 cc. of chloroform and 20 ce. of pepsin solution containing 0.150 
gram of Parke Davis & Co.’s aseptic scale pepsin. The bottles 
were kept at 98° F.. (87° C.) and examined at intervals. Enough 
bottles were prepared in each case so that one bottle was used for 
each examination, no bottle being opened until analyzed. The 
analytical results are given in the accompanying table: 
TABLE [X.—SHOwING DIGESTION oF PARACASEIN AND PARACASEIN 
MoNOLACTATE BY PrEPSIN WitHouT FREE AcIpD. 
| 
F PERCENTAGE OF NITROGEN IN MATERIAL 
EXPRESSED IN ForM oF WATER-SOLU- 
BLE NITROGEN. 
Material Nitrogen | Nitrogen | Nitrogen : | | 
containing ‘in 4 in form | in In4 | In8 In 24 | In 48 | In 72 
material. | of para- | material | hours. | hours. | hours. | hours. | hours. 
casein in solu- | 
monolac- | ble form. | 
tate. 
Per ct. Per ct. Per ct. | Perct. | Per ct. | Per ct. | Per ct. ; Per ct. 
Paracasein........ 4.11 2.43 6.62 6.62 7.06 7.64 | 6.62 
aracasein | 
monolactate.... 3.52 1.27 3.98 | 17.00 | 22.62 | 22.91 | 40.78 45.96 
These results show that the paracasein failed to digest, while 
the paracasein monolactate digested quite rapidly, when we con- 
sider the absence of free acid. 
(2) Comparison of digestibility of casein monolactate and 
casein dilactate without acid.—The casein monolactate was pre- 
pared by treating 20 pounds of milk with 32.6 grams of lactie 
acid. On heating at 98° to 104° F. (87° to 40° C.) the monosalt 
Separated as a characteristic rubber-like mass. A portion of it 
on testing was found to dissolve completely in a 5 per ct. solu- 
tion of sodium chloride. The casein dilactate was prepared by 
allowing milk to sour in the usual way for making Dutch cheese. 
These materials, carefully washed, were prepared for digestion as 
described under (1) preceding, except that in each bottle we used 
0.200 gram of pepsin in place of 0.150 gram and one per ct. of 
chloroform instead of three per ct. The amount of nitrogen in 
each bottle was 0.830 gram. No acid was added to the contents of 
the bottles. The results are tabulated below: 
