14

we were able, by using Bryant and Milner's method, to get figures for the co-
efficient of protein absorption that were at all comparable with those of Rubner,
Atwater, etc.

    We found that for different quantities of the food-stuff in the diets.
examined different proportions of their contained protein were absorbed, and that,
instead of finding a figure that represented the percentage of protein absorbed for
varying amounts of rice, wheat, dal, etc., for each separate quantity of rice,
wheat, dal, etc., above a certain amount, a different percentage of its contained
protein would be absorbed. This is a very different result from what would appear
to be the case from the work of investigators in Europe and America; but it is
covered by a simple explanation. If we assume that 85 per cent. is the maximum
of protein absorption possible on a diet of cereals and legumes, then, under ordi-
nary physiological conditions, that 85 per cent. will be absorbed; this is what takes.
place in the class of diets in which investigations on the co-efficient of protein
absorption have been carried out in America and Europe—the quantities added
to the basal diet have never caused the total diet to exceed the amount the
stomach and intestinal juices were capable of dealing with.

    Now, when a gradual increase in the quantity or mass of the diet is made,
after a time there is reached a point at which the mass or bulk begins to interfere
with absorption, and any further increase causes greater and greater interference,
so that there is a fall in the percentage of protein absorption from the assumed
85 per cent. to a much lower figure whose value depends on the greater or less
interference that has taken place; this is what we have found to be the case in
the dietaries of the Bengal jails—the quantities of the several food-stuffs over-
step the physiological limits with the result that absorption is greatly interfered
with and, instead of having an all round absorption of about 85 per cent. as
obtains in Europe on vegetable diets, we have an absorption, from the ordinary
jail dietaries that barely touches 55 per cent. What is true for these diets as a
whole is equally so for the different food materials composing the diets, whether
these be rice, wheat ata or dal.

    For these reasons early in the investigation we had to give up all idea of dis-
covering more or less constant figures that would represent the percentages of
protein absorption from the different food-stuffs composing the jail dietaries. If
such constants had been found then the arranging of jail diets based on the real,
nutritive value would have been a fairly simple matter. As owing to the above
mentioned circumstances this method was found impossible we next turned to the
variations in the nutritive value of the diet scales as a whole in order to discover
what combination of the several items of the diets gave the most favourable results,
and in what quantities these several items should be combined. It will be fairly