skull; and then, in order to poise the skulls on the perpendicular
rod, it was necessary to more them forward on the point of the rod;
but it was necessary to shift the Negro skull considerably further
forward than the European : the point of the rod thus indicating
by its removal backward on the scale that the lower jaw of the
Negro bore a greater proportion to the skull than that of the Eu-
ropean. The facial line was of course thrown further backwards in
both skulls on taking away the jaw; but the jaw of the Negro being
larger than that of the European, the inclination backward was
greater in the Negro skull. On proceeding to take away the upper
jaws, and then the whole bones of the face, I found, by the index on
the degrees marked on the surface of the cranium, that the jawbones
of the Negro bore a much greater proportion to the head
and the other bones of the face, than those of the European skull;
and that the apparent size of the bones of the Negro face proceeded
only from the size and form of the jaw-bones, while the
upper bones of the face, and indeed all that had not relation to
the teeth and mastication, were less than those of the European
skull.
In proceeding with these experiments, I found reason to change
my manner of noting the variations. I found that the angle formed
betwixt the perpendicular and a line drawn from the occipital hole
to the superior margin of the orbit of the eye, served the most
distinctly to mark the variations in the inclination of the cranium.
Besides, I now wished to measure the cranium itself, and I found
that a scale marked on the great convexity of the skull varied with
the form of the cranium. Preserving the principle, I measured the
inclination of the cranium by the elevation of the line intermediate
betwixt the cranium and face.
On suspending the cranium on the perpendicular rod, having
taken away all the bones of the face, I found that the Negro
cranium had the base line elevated nearly ten degrees more than
the European. I found, on comparing the cranium of a child with
that of an adult, that it wanted weight and capacity on the forepart__
that the line was depressed by the increasing size of the
forehead as we advanced in maturity.
Upon looking attentively to these skulls, it was evident that
there were distinctions to be observed in the form of the cranium
itself, independently of the proportions between the face and
cranium; that these varieties depended on the form of the brain,
and proceeded (I think we may conclude) from the more or less
complete development of the organ of the mind. In the infant
there is a deficiency of weight, and a less ample area in the higher
and anterior part of the brain case. I say less ample, only in reference
to what we may estimate as the standard, viz. the adult
European. In the Negro, besides the greater weakness and lightness
observable in the bones of the whole skull, there is a remarkable
deficiency in the length of the head forward, producing a
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