inexperience of those who practice it. With negroes it is
unnecessary, except in some rare instances. Their diseases, like their
passions, have each its peculiar expression stamped in the countenance.
They are like young children in this respect. They cannot disguise their
countenance like white people. An intelligent and observant observer can
tell from their countenance when they are plotting mischief, or have
committed some crime; when they are satisfied or dissatisfied; when in
pleasure or in pain; when troubled or disturbed in mind; or when telling
a falsehood instead of the truth. An observant physician has only to
bring the old science of prosoposcopia, so much used by Hippocrates in
forming his diagnosis, to bear upon negroes, to be able, by a little
experience, to ascertain the most of them at a glance by the expression
of their countenance.

They are very subject to fevers, attended with an obstructed circulation
of air and blood in the pulmonary organs. Their abundant mucosities
often prevent the ingress of air into the air cells, bloating their lips
and cheeks, which are coated with a tenacious saliva. A cessation of
digestion from too full a meal, or some hepatic or other derangement, is
soon attended with such a copious exudation of mucosities, filling the
air cells and tracheal passages, as to cause apoplexy, which with them
is only another name for asphyxia. The head has nothing to do with it.
So abundant are the mucosities in negroes, that those in the best health
have a whitish, pasty mucus, of considerable thickness on the tongue,
leading a physician not acquainted with them to suppose that they were
dyspeptic, or otherwise indisposed. The lungs of the white man are the
main outlets for the elimination of carbonic acid formed in the tissues.
Negroes, however, by an instinctive habit of covering their mouth, nose,
head and face with a blanket, or some other covering, when they sleep,
throw upon the liver an additional duty to perform, in the excretion of
carbonic acid. Any cause, obstructing the action of the liver, quickly
produces with them a grave malady, the retention of carbonic acid in the
blood soon poisoning them.

Hence with white people a moderate degree of hepatic obstruction, by a
residence in swampy districts, is often found beneficial in diminishing
the exalted sensibility and irritability of phthisical patients. Viscous
engorgements of the lungs destroy more negroes than all other diseas