is just sufficient to keep the body in equilibrium. This latter plan is the best, but to be quite satisfactory must be tried on a large number of suitable persons under varying conditions, both of quantity and kind of food. Nearly all the experiments have been made on persons accustomed to a stimulating dietary: their usual food has included a considerable quantity of flesh and alcoholic drinks. Sufficient attention has not been paid to the dietaries of the more abstemious races who partake of little if any flesh food. The standard daily dietary for a man of average weight, doing a moderate amount of work, is variously stated by the best authorities as proteids from 100 to 130 grammes, fat 35 to 125 grammes, and carbo-hydrates 450 to 550 grammes. There is a surprising difference of opinion on the amount of fat, but those who give least fat give the largest quantity of carbo-hydrate and vice-versa. Dr. R. Hutchison in "Food and Dietetics," sums up the quantities given by the highest authorities as follows:—-

The nutrient ratio is 1 : 4.9. For scientific purposes, metrical weights and measures are used, instead of the inconvenient English grains, ounces, pounds, &c. (1 gramme = 15.43 grains; 1 ounce avoirdupois = 437.5 grains = 28.35 grammes). A calorie is a measure of the power of a food in generating heat and muscular energy (these two being convertible).