experiment on a wheatmeal dietary, it will not do to assume that less than
82 grammes of proteid would have been insufficient. It is probable that a
smaller quantity of proteid would have been enough if the fat and
carbohydrates had been increased. The calories are below the usual
standard. In the succeeding example the calories are considerably higher,
being not far from the usual standard, yet 54 grammes of proteid sufficed.
It is a common error to place an undue value on the proteids to the extent
of overlooking the other constituents. Dr. Alexander Haig in "Diet and
Food," p. 8, cites the case of a boy aged 10, fed on 2-1/4 pints of milk
per day. The boy lost weight, and Dr. Haig is of opinion that the quantity
of milk was very deficient in proteid; more than twice as much being
required. 2-1/4 pints of milk contain about 45 grammes of proteid,
whereas, according to the usual figures (125 x 6/10) a boy of this age
requires 75 g. This quantity of 45 g. is however, higher, allowing for the
boy's age, than that in several of the dietaries we have given in our
table. A little consideration will show that Dr. Haig has overlooked the
serious deficiency of the milk in the other constituents, which accounts
for the boy's loss of weight. The quantity of milk contains only about 160
g. of total solid matter, whilst 400 g. is the necessary quantity. Milk is
too rich in proteid matter to form, with advantage, the sole food of a
human being. Human milk contains much less in proportion to the other
constituents.

The old doctrine enunciated by Justus von Liebig was that proteid matter
is the principal source of muscular energy or strength. He afterwards
discovered and acknowledged his error, and the subject has since been
thoroughly investigated. The makers of meat extracts and other foods,
either from their own ignorance of modern research or their wish to take
advantage of the lack of knowledge and prejudice of the public, call
proteid matter alone nourishment. The carbo-hydrates and fats are equally