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Diet A.

Total intake— Total output of nitrogen—
    N. of Burma rice     68.00 grms.     N. of urine       =180.27 grms.
    N. of mung dal     172.95 „     .5 grm. of N.daily constant   = 12.50 „
    N. of makkai ata     110.25 „      
    N. of vegetables     11.80 „ Total N. metabolism     =192.77 „
             =53.10 per cent. of N. of diet
Total N. of intake   =363.00 „        =  7.71 grms. N. per man daily.

Diet B.

Total intake same as A   =363.00 grms. Total output of nitrogen—
    Add N. of mutton   = 52.15 „     N. of urine       =225.89 grms.
          .5 grm. of N. daily constant = 12.50 „
Total N. of intake =415.15 „      
  Total N. metabolism =238.39 „
         =57.42 per cent. of N. of diet
         =  9.53 grms. N. per man daily.

Now if we falsely assume, as has always hitherto been done in investigations
carried out to obtain the co-efficient of absorption of the nitrogen of different
food-stuffs in European diets, that the same amount of nitrogen will be
absorbed from the basal part of these Diets A and B, i.e., that the same quantity
of nitrogen will be absorbed from Diet A as will be absorbed from the basal part
of Diet B (Diet B=Diet A+mutton) we can, by the method employed in Europe
and America, obtain a figure representing the percentage of the nitrogen of the
mutton that is absorbed.

           From Diet A we get an absorption of 192.77 grms. nitrogen.
           From Diet A + mutton (B) absorption of 238.39 grms. nitrogen.

      Therefore, on above assumption—

             52.15 grms. nitrogen of mutton gives an absorption of 45.62 grms. or 87.47 per cent.

       So that, on the above assumption the nitrogen of goat's flesh is absorbed
to an extent of 87.47 per cent.; but, while this percentage is true for these parti-
cular experiments, it does not hold good in other experiments where the basal part
of the diet is made up differently. In other words, the figure representing the
percentage of protein of mutton absorbed, obtained from experiments carried out in
this way, depends very largely on how the basal diet is made up. The protein of
mutton is very much more easily assimilated than is the protein of either rice, dal
or ata; and therefore on adding mutton to a basal diet, although we get an increase
in the amount of protein absorbed and undergoing metabolism, the increased output
of nitrogen in the urine is not a measure of the amount of protein absorbed from the
mutton. It may vary in two different ways:—

      1. It may happen to be the measure of the amount of nitrogen absorbed from