DIGESTIBILITY OF SOME NUT OILS. 11 
Summary of digestion experiments with butternut oil in a simple mixed diet. 
Experiment No. 
Subject. 
Protein. 
Fat. 
Carbo- 
hydrates. 
Ash. 
732 
R.F.C 
P. K 
Per cent. 
45.5 
61.2 
72.6 
Per cent. 
85.3 
86.2 
94.7 
Per cent. 
96.2 
97.5 
97.2 
Per cent. 
28.8 
733 
45.8 
734 
J. e. M.. 
63.7 
Average 
59.8 
88.7 
97.0 
46.1 
The supply of butternut oil obtainable was small and so it was not 
possible to provide as large a quantity of it per day as was the case 
with the other oils studied, and the average daily consumption was 
only 46 grams per man. The butternut-oil blancmange was as palat- 
able as the similar dish used in the other tests, and there is every 
reason to believe that more of the oil would have been eaten had it 
been possible to supply a blancmange richer in it. The digestibility 
of the total fat in the diet was found to be 88.7 per cent. The calcu- 
lated digestibility of butternut oil alone, which represented the 
greater part of the total fat, when estimated in the usual manner, 
with corrections for metabolic products and undigested fat from the 
basal ration, is 95.4 per cent, a value which compares favorably with 
the digestibility of other food oils which have been studied. 
The protein and carbohydrates supplied by the ration were utilized 
as completely as in other experiments of this series, being 60 per cent 
and 97 per cent digested, respectively. Considering the results as 
a whole, it is apparent that butternut oil, expressed from fresh, sound 
butternuts, when eaten as a constituent of a simple mixed diet, is a 
well assimilated and palatable food oil. 
ENGLISH-WALNUT OIL. 
The English or Persian walnut tree {Juglans regia) is widely dis- 
tributed, and the nuts are very generally used for human food. Eng- 
lish-walnut oil is expressed for illuminating and for edible purposes 
in several parts of Europe. The cold-pressed oil is almost colorless 
and has a pleasant smell and agreeable taste, while, according to 
Lewkowitsch, 1 if hot pressed it has a greenish tinge and acrid taste 
and odor. 
A survey of the literature revealed little information as regards 
the digestibility of English- walnut oil. Jaffa x made a series of 11 
digestion experiments in which he studied the digestibilty of walnuts 
eaten in conjunction with other common food materials. On an aver- 
age the subjects ate 97 grams of fat per day, of which 86 grams was 
walnut oil. The digestibility of the total fat of the diet was 85 
per cent. Since the fat derived from the other constituents of the 
1 Loc. cit. 
