replaces L220,000,000 worth of labor, we may reckon the wages
of a steam man power at L7, or $35, per year, exclusive of food (fuel)
and lodging.

* * * * *

THE NEGRO'S COLOR.

The chemical character of the coloring matter in the negro's skin has
been investigated by Dr. F. P. Floyd, in the laboratory of the
University of Virginia. Strips of skin were well washed with water and
alcohol, in order to remove fatty matter, and then cautiously scraped
with a blunt scalpel, to loosen up the pigment granules. This must be
carefully done, for an examination of the scraped skin shows that the
whole substance of the cuticular tissue may easily be broken up and
mingled with the pigment, which cannot then be obtained pure. But by
selecting the most strongly colored parts and treating them carefully,
the following points were established: The coloring matter is insoluble
in water, alcohol, and ether. It is also unaffected by dilute acids or
dilute solutions of alkali. The strong acids, even concentrated nitric
acid, attack it but slowly. Chlorine destroys it especially in presence
of alkali. Heated for some time with a strong solution of sodium
hydrate, it is gradually dissolved, and from the diluted solution it
may be partially precipitated on neutralization with an acid. The ash
of the negro skin gave twice as much ash as the white skin, or 2.4 per
cent. against 1.15 per cent. Analyses of the ash for iron showed 2.28
per cent. of metallic iron in the black and 1.21 per cent. in the white
skin. These facts confirm the general impression that the color of the
negro's skin is nearly allied to the "melanin," or black pigment of the
choroid coat in the eye. Both seem to be products of alteration of the
blood.

This pigment appears to be similar to or identical with the black
coloring matter of feathers. When perfectly white hair or feathers are
heated gently with dilute sulphuric acid, they dissolve completely,
though slowly. Black or brown feathers leave an insoluble residue. This
subject was lately presented to the London Chemical Society by Messrs.
W. R. Hodgkinson and H. C. Sorby. They took feathers of the English
rook, which contain one per cent. of pigment, and having cut the vanes
from the central rib, cleaned them from fat by treatment with alcoholic
ammonia. Warm dilute sulphuric acid was then applied, until it was no
longer colored, and the residue was treated with dilute hydrochl