2

The present enquiry aims at estimations of the actual amount of some of the
proximate principles— especially protein—that are absorbed and assimilated, and
for this reason the papers above referred to, while of great importance so far as they
go, do not give much assistance in the present work.

        Surgeon Major T. R. Lewis* writes: "A mere tabula statement of the several
ingredients constituting the several diets would be of comparatively little value un-
less accompanied by a statement of their chemical composition; and, in order to
judge of the comparative merits of dietaries so analysed, it is essential that a clear
conception should be formed as to what particular portions are specially adapted
to the nutrition of the body." To this we may add that it is of even more import-
ance to know in what proportions the proximate principles of the different food-
stuffs are absorbed and made use of in the economy.

        It is futile, for example, to work out diet scales furnishing say 80 grammes of
protein per man daily, if instead of 90 per cent. only 60 per cent. of this is
absorbed, and then imagine that we have provided for the prisoners' physiological
needs. Yet, so far as we have been able to find in the literature of this subject
that is what has been done hitherto.

        The diet scales would also appear to have been based on those in use in the pri-
sons of European countries, an allowance being made for difference in weight.

        So far back as 1881 Lewis wrote, and it is equally true to-day :—" So far
as I am aware, no systematic series of observations has been conducted
on the precise food-requirements of the inhabitants of this country when under-
going laborious exertion, as compared with the requirements when the body is at
rest, so that all inferences as to what these requirements are, are based on experi-
ments made in Europe and on people accustomed to a far larger proportion of
animal food than the great majority of the inhabitants of Eastern countries."

        The first work done on the subject by actual experiment, to which we have
reference, is an able and interesting memorandum by Surgeon Major I. B. Lyon,†
Chemical Analyser to Government, Bombay. From actual experience of native
prisoners on hard labour in the Bombay House of Correction, Dr. Lyon devised
three scales of diet, based on the analysis of the diet on which these prisoners
had been working and which had proved sufficient.

        We need not go into the details of this paper: it will be sufficient for our
purpose to say that the work done by Dr. Lyon was carried out from the exactly
opposite point of view to that recorded in this memoir.

        Dr. Lyon found that native prisoners in the Bombay House of Correction in-
creased in health, weight and physical development when sentenced to hard labour ;

        *A memorandum on the Dietaries of Labouring Prisoners in Indian Jails-Annual Report of the
sanitary Commissioner with, the Government of India for 1880, page 159.

      † Memorandum by Surgeon Major I. B. Lyon, F.C.S.—Gazette of India, 19th May 1877.