DIGESTIBILITY OF OILS AND FATS. 
assimilated, no physiological disturbance was noted, and the deer 
fat, though its melting point is rather high as compared with common 
food fats, did not lower the digestibility of the other ingredients of 
the diet. 
The average figure reported for digestibility of deer fat, 81.7 per 
cent, is considerably lower than that found in most of the experi- 
ments made in this laboratory with fats. The only exceptions were 
hydrogenated peanut oil which had a melting point of 52.4° C. and 
showed practically the same coefficient of digestibility, 16 79 per cent, 
and oleo stearin which was 80.1 per cent digested. 17 
Though the amount of deer fat eaten per man per day is small 
compared with other fats previously studied in this laboratory, it 
constituted the major portion of the total fat eaten in all three tests 
and there seems no reason to doubt the accuracy of the results. 
The average results of the experiments with cod-liver, Java- 
almond, tea-seed, and watermelon-seed oils and deer fats are sum- 
marizd in Table 6. 
Table 6. — Summary of results of digestion experimeiits with certain miscel- 
laneous oils and fat in a mixed diet. 
Digestibility of entire ration. 
Digesti- 
bility of 
oil or fat 
alone. 
Material tested. 
Protein. 
Fat. 
Carbohy- 
drate. 
Ash. 
Cod-liver oil 
Per cent. 
50.5 
41.4 
Per cent. 
92.6 
92.2 
Per cent. 
96.4 
93.4 
98.4 
97.9 
93.0 
Per cent. 
53.1 
51.4 
42.1 
37.1 
44.5 
Per cent. 
97.7 
97.0 
Tea-seed oil 
47.2 1 88.2 
56.9 90.7 
52. 2 73. 6 
91.2 
94.8 
Deer fat 
81.7 
BLENDED HYDROGENATED FATS. 
During the last 10 or 15 years th6 hydrogenation process has come 
prominently into use for the preparation of solid fats from liquid oils. 
This procedure, although limited in general use to those oils which 
have a fairly large amount of unsaturated fatty acids, finds applica- 
tion in the hardening of a number of vegetable and animal oils that are 
produced in quantity. 
There are two general methods for the preparation of hydrogenated 
fats.- In one, all the oil is subjected to the hydrogenation process 
until a fat of the desired melting point is obtained. In the other, part 
of the oil is hydrogenated until a fat with a very high melting point 
is obtained, which is then mixed with a sufficient amount of the un- 
treated oil to give a fat of the desired melting point. In the discus- 
16 Amer. Jour. Physiol., 54 (1921), No. 3, pp. 479-488. 
17 U. S. Dept. Agr. Bui. 613 (1919). 
