hite boy expelled from
his lungs a larger volume of air than a negro half a head taller and
three inches larger around the chest. The deficiency in the negro may be
safely estimated at 20 per cent, according to a number of observations I
have made at different times. Thus, 174 being the mean bulk of air
receivable by the lungs of a white person of five feet in height, 140
cubic inches are given out by a negro of the same stature. It must be
remembered, however, that great variations occur in the bulk of air
which can be expelled from the chest, depending much upon the age, size,
health and habits of each individual. But, as a general rule, it may be
safely stated, that a white man, of the same age and size, who has been
bred to labor, is, in comparison to the negro, extra capacious. To judge
the negro by spirometrical observations made on the white man, would
indicate, in the former a morbid condition when none existed. But I am
free to confess that this is a subject open to further observations. My
estimate may be under or over the exact difference of the capacity of
the two races for the consumption of oxygen.

The question is also answered _anatomically_, by the comparatively
larger size of the liver, and the smaller size of the lungs; and
_physiologically_, by the _roule_ the liver performs in the negro's
economy being greater, and that of the lungs and kidneys less, than in
the white man. But I have not the honor to be the first to call
attention to the difference in the pulmonary apparatus of the negro and
the white man, and to the fact of the deficiency in the renal secretion.
The honor is due to Thomas Jefferson, the third President of the United
States. In his Notes on Virginia, Mr. Jefferson suggested that there was
a difference in the pulmonary apparatus of negroes, and that they do not
extricate as much caloric from the air by respiration, and
consesequently consume less oxygen. He also called attention to the fact
of the defective action of the kidneys. He remarks, "To our reproach be
it said, that although the negro race has been under our eye for a
century and a half, it has not been considered as a subject of natural
history." Another half century has passed away, and nothing has yet been
done to acquire a knowledge of the diseases and physical peculiarities
of a people, constituting nearly a moiety of the population of fifteen
States of the American confederacy, and whose labor, in cultivating a
single