appears to be endowed with a species of vitality, or organization
Susceptible of vascular action, sinèe it undergoes ©dr»
tain changes in disease, which' cannot be accounted for On
any other principle. . In the plica polonica, il ls said, that
the hairs bleed when Cut : if is well known that they become
white in old age, and grief and - anxiety have been observed
to render them white inva very short space of time. Bichât
affirms that he h a sse e n a t least »five or six examples in which
such a change ofjcolpui has taken place inJlèaâ than eight
days gj in one person, known to the sâln© writer, the hair became
almost entirely white in the space of one-flight, the
effect of some sudden and poignant grief. It is doubtless in
this vascular, medulla, whatever its structure may be, th a t
the colour of the hair resides. The outer covering is of a
substance analogous to the cuticle, the nails, and the horns
of animals.
The colouring principle is manifestly of a Common nature
in th e skin and hair. It has been asserted by a French
anatomist,* who has displayed much ingenuity, in his ^'researches
into this subject, that the colouring mätter of the
skin is produced and secreted in the bulbs of the hair. 'This
opinion was formed from an attentive observation of thè
phænomena which ensue after the black pigment*; in the- skin
of the Negro, has been destroyed by the application of blisters,
or by any means producing vesication; In the procek
of restoration the black matter first begins to Teappear at the-
ppres through which the hairs make their exit.' VFrom these
pores, as from centres, it is gradually seen ramifyirig'in different
directions, and insensibly proceeds to cover the whole
space which had lost its colour. The same opinion receives
some support from the fact, that parts which are most completely
devoid of hair, as the soles of the fèëf, arid the palms
o f the hands, are in 'th e Negro and other black men, of a
much lighter shade than the rest of the body. In spotted
Negroes, or Negroes who have white spots on parts of their
bodies, it has been remarked that the hairs issuing from the
white patches, are themselves perfectly white. Still it is
* Récherches sur l’Organisation dé jà Peau, &c. par M. Gaultier.
scarcely possible that the bulbs can be the only seat of the
secretion; of this colouring matter, for the skin of the Negro
is occasionally black in some parts which are quite destitute
of hair, as on the inside of, the,, lips. The secreting fabric,
whence-issues the colouring matter,.is apparently spread in
a certain degree over the, whole cutis,.
Whatever conclusion may be the true one on some of these
points, it is undoubted, that a close connexion exists between
the colouring principle .jn both, of these parts.
For the sake of facilitating comparison, I-shall »divide the
hair into crinal and pilar, - terpaing -crinal that of the head,
beard, and pilar that/which grows* upon the trunk, particularly
on . tbeVb^east and. onjfthp limbs., The manes and
tails of horses, .and .other animals, are analogous to the 'cririhl
hair of mankind,; a n d .^ e hair which is generally spread over
their bodies is analogous to the pilar.
:,|$O T E ON SECTION I. AND II.
From what has heen said of the seat and cause of variety
in complexion, it must he apparent, that in the instances before
described, a light }Cp|purqf the skin and eyes makes its a p pearance
in dark jaces ■ the choroidpf -tbe-eye (being- coloured
as in fair,Europeans, and the hair yellow, or red, are examples
o£iVthe xanthous and not of the leucous variety, since the
pigment is present which gives a hue to the eyes in persons
of the former class, as well as the colourings matter in the
hair.
It must be apparent to the reader, that as the colour of the
skin passes by a gradual transition from the deeper black to
a light shade, and even to a white or colourless state, we can-
not well divide human races into particular classes by reference
to the complexion of their skins. The colour of the eye
displays more strongly marked divisions, but, on the whole,
the hair chiefly, but in conjunction with other characters, affords
the most convenient principle of arrangement.