DIGESTIBILITY OF SOME SEED OILS. 13 
The average coefficient of digestibility of the total fat of the diet 
was found to be 94.9 per cent. While the subjects on an average 
ate only 81 grams of fat daily, over 97 per cent was mustard-seed 
oil and the value for the digestibility of the total fat is increased 
when allowance is made for the ether extract of the feces resulting 
from the basal diet to 95.8 per cent for the digestibility of mustard- 
seed oil alone. 
No attempt was made to feed larger quantities of the oil in order 
to secure data in regard to the limit of tolerance of the body for 
mustard-seed oil. In two of the experiments, Nos. 615 and 616, the 
subjects reported a slight diarrhea, and so it would seem that the 
limit of tolerance for this oil was not much in excess of 87 grams 
daily, the amount of mustard oil eaten by one of the subjects. It is 
quite possible, however, that the limit of tolerance for highly refined 
oil might be greater than that of the unrefined oil which was used. 
The protein and carbohydrates furnished by the diet were 71 per 
cent and 95 per cent digested, respectively, values which compare 
favorably with the thoroughness of digestion of these constituents 
usually found in earlier tests in which the same basal ration was 
eaten. As a whole the diet supplied 35 grams of protein, 81 grams 
of fat, and 323 grams of carbohydrates daily and had a fuel value 
of 2,160 calories. 
RAPESEED OIL. 
The refined rapeseed oil of commerce is of a pale yellow color, 
possesses a characteristic taste, and is prepared from the seeds of the 
rape plant (Brassica napus). 
Though rapeseed oil is not produced in the United States to any 
extent for edible purposes, cold-pressed rapeseed oil is used in 
Europe and especially in India for food purposes. In a discussion 
of commercial rapeseed oil, Lewkowitsch x states that this oil, called 
" bread " oil, is largely used in England by bakers for greasing the 
ends of loaves of bread to prevent their sticking together when 
baked. 
No records of any direct determinations of the digestibility of this 
oil have been found in the literature consulted. However, in a study 
of the comparative digestibility of a rice and tofu diet with and 
without rapeseed oil, Suchi 2 found that the total fat of the diets 
was 93.9 per cent and 96.5 per cent digested, respectively. The au- 
thor, who served as the subject of the experiments, ate in the latter 
experiment approximately 58 grams of fat daily, this amount being 
1 Chemical Technology and Analysis of Oils, Fats, and Waxes. London : Macmillan and 
Co., Limited, 1909, vol. 2, p. 205. 
2 U. S. Dept. Agr., Office Expt. Stas. Bui. 159 (1905), p. 153. [Tokyo Igakukwai 
Zasshi (Jour. Tokyo Med. Soc), 2 (1888), pp. 457, 511.] 
