182

     This means that 0.38 grm. NaCl per man daily is passed in the fæces, a lower
figure than is usually obtained.

    Our reasons for giving this series are the increase in the amount of salt
passed in the fæces when the dal is increased, and the diminished amount of salt pre-
sent when the amount of dal is decreased. We found under the ordinary conditions
of jail diet that the amount of salt appearing in the fæces was practically constant
at 0.5 grm. per man daily; we now find that by varying the amount of dal in the
diet a corresponding variation takes place in the elimination of salt in the fæces.
This would appear to show that the salt of the fæces is largely derived from the dal
in diets of the Lower Bengal type, and that dal is, therefore, less thoroughly digest-
ed and broken up than the other constituents of the diet.

    A great many investigations besides those referred to have been made on the
effects of increasing and decreasing the amount of salt in the daily food of prisoners ;
in fact, the estimations of the chlorides in the excreta were made in all the meta-
bolism experiments. Nothing save the points already brought out in the examples
we have given is at present evident.

    One fact with regard to the Behari type of diet we may mention, viz., that the
amount of salt passed in the fæces is higher than in the diets of Lower Bengal,
being nearly 1 grm. per man daily. This we would expect from the larger amount
of salt contained in wheat and maize than in rice, and the greater actual amount
of the diet that is unabsorbed and passed in the fæces. The outstanding features
of the results of these investigations on salt metabolism are the very high degree
of absorption of salt that does occur, and the comparatively small amount found
in the intestinal excreta.

    In Chart XV we give in graphic form the effects of varying the quantity of
salt in the diet on the amount of salt eliminated by the skin, the quantity of urine
excreted, and on the percentage body-weight.