The remarks of Dr. Robertson may also be here introduced. "The
advantage," he observes, "of using more or less of the coverings of
the grain in the preparation of bread has often been urged on
economical principles. There can be no doubt that a very large
proportion of nutritive matter is contained in the bran and the
pollard; and these are estimated to contain about one-fifth part of
the entire weight of the wheat grain. It is, unquestionably, so far
wasteful to remove these altogether from the flour; and in the case
of the majority of people, this waste may be unnecessary, even on
the score of digestibility."[32] This subject can also be rendered
apparent to the eye. If we make a cross section of a grain of wheat,
or rye, and place it under the microscope, we perceive very distinct
layers in it as we examine from without inwards. The outer of them
belong to the husk of the fruit and seed, and are separated as bran,
in grinding. But the millstone does not separate so exactly as the
eye may by means of the microscope, not even as accurately as the
knife of the vegetable anatomist, and thus with the bran is removed
also the whole outer layer of the cells of the nucleus, and even
some of the subjacent layers. Thus the anatomical investigations of
one of these corn grains at once explains why bread is so much the
less nutritious the more carefully the bran has been separated from
the meal.[33] There can therefore be little doubt that the removal
of the bran is a serious injury to the flour; and I have presented
the above array of evidence on this point in the hope of directing
public attention to it here, as has been done in various foreign
countries.

After this, it will easily be inferred that I am not disposed to
look with much favor upon the plan proposed by Mr. Bentz for taking
the outer coating or bran from wheat and other grains previously to
grinding.[34] Independently of the considerations which have already
been presented, it is far from being proved, as this gentlemen
asserts, that the mixture of the bran with the meal which results
from the common mode of grinding is the chief cause of the _souring_
of the flour in hot climates. On the contrary, the bran is perhaps
as little liable to undergo change as the fine flour, and then the
moistening to which, as I am informed,