o their stomachs. No European could cram so much at a
time; and they very commonly allow that rice alone will not nourish
them. They very generally still eat a quantity of bread."[35] In
regard to the proportion of nutritious matter contained in grains of
various kinds, it may be remarked that the tables which have been
constructed as the results of various experiments are liable to an
objection, which will be more particularly adverted to under another
head. For example, two substances, by the process of ultimate
analysis, may exhibit the same proportion of nitrogenous matter, and
still differ very materially in their value as articles of food.
Much depends on the digestibility of the form in which this matter
is presented to the digestive organs. A strong illustration is
afforded in the case of hay, the proportion of nutritive matter of
which, about 9.71, would certainly not represent its power of
affording nourishment to the human system. It is in truth quite
impossible to arrive at any other than approximate results from the
operations of chemistry, as to the amount of nutriment contained in
a given quantity or weight of any article of food.[36] It is perhaps
not irrelevant to notice in this place some of the researches which
have recently been made upon fermentation, and particularly its
effects in the manufacture of bread. It appears that when this
process is brought about by the addition of yeast or leaven to the
paste or dough, the character of the mass is materially altered. A
larger or smaller proportion of the flour is virtually lost.
According to Dr. William Gregory the loss amounts to the very large
proportion of one-sixteenth part of the whole of the flour. He says,
"To avoid this loss, bread is now raised by means of carbonate of
soda, or ammonia and a diluted acid, which are added to the dough,
and the effect is perfectly satisfactory. Equally good or better
bread is obtained, and the quantity of flour which will yield
fifteen hundred loaves by fermentation, furnishes sixteen hundred by
the new method, the sugar and fibrin (gluten) being
saved."--("Outlines of Chemistry," p. 352.)

Another author, Dr. R.D. Thomson, states, as the results of his
experiments upon bread produced by the action of hydrochloric acid
upon carbonate of soda, "that in a sack of flour there was