DIGESTIBILITY OF SOME ANIMAL FATS. 19 
which was eaten on an average. No physiological disturbance was 
noted with the other fats tested. Such matters have a practical 
value in discussing dietetics, aside from the theoretical question 
whether this laxative property is . ascribable to differences in the 
chemical structure of the fats or to some other factor. 
The average coefficient of digestibility of brisket fat is higher than 
that previously found for beef (kidney) fat (93 per cent)/ which is in 
accordance with the observation that the digestibility is inversely 
proportional to the melting point. The other fats studied were either 
fluid or had a melting point not far from room temperature, so it was 
not surprising to find that they did not show marked variations in 
thoroughness of digestion. 
The average digestibility of carbohydrates in the different tests was 
found to vary only from 96.1 to 96.9 per cent, while the digestibility 
of this food constituent in the average mixed diet has been found to 
be 97 per cent. 2 This close agreement would indicate that the con- 
sumption of fat did not exercise any unusual effect upon carbohydrate 
digestion. 
As a whole, the results of the digestion experiments indicate that 
chicken fat, goose fat, brisket fat, cream, egg-yolk fat, and fish fat 
are all well assimilated and that they are satisfactory sources of fat 
for the dietary. Since butter fat eaten in the form of cream and 
egg-yolk fat are very thoroughly digested and easily obtainable and 
apparently contain or carry with them accessory food substances 
necessary in the diet for growth and general well-being, a wide use of 
these two fats in the dietary is especially desirable. 
i U. S. Dept. Agr. Bui. 310, p. 21. 
2 Connecticut Storrs Sta. Rpt. 1901, p. 245. 
