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 hydrochloric acid and boiling alcohol and ether. Black pigment is usually found in black, brown, and dark red hair, but in the latter it is associated with a brown pigment that is soluble in dilute sulphuric acid.

Experiments were made by Dr. Floyd to determine the position of the pigment in the negro's skin. Many Southern physicians are under the impression that a blister upon the black skin is white, or nearly so. But this was disproved by experiment, and the microscope showed that the granules were dispersed through the whole of the cuticle, though less dense at the surface than in the deeper tissues. In fact Dr. Floyd thinks that the pigment originates in the outer layer of true skin, "its production being probably connected with the loss of vitality of the cells, and that it accompanies those cells all the way to the surface, where it is mechanically removed by desquamation." The alteration of the red blood corpuscles to black pigment may be due to feeble circulation in the superficial capillaries. The diseases of negroes, and their extreme sensitiveness to low temperatures, sustain this view.

The jurisdiction of London extends over 756 square miles; its area embraces 78,000 acres. It contains 4,000,000 of inhabitants, increasing at the rate of 75,000 a year, of various nationalities.

The rapidity of sewing machine work, even when not working beyond an ordinary manufacturing speed, is seen in the manufacture of 110 three-bushel sacks per hour, containing 35,640 stitches, or close on 600 per minute.

The pine woods of Michigan are said to contain in standing trees—

In Eastern Michigan 13,500,000,000 feet.
In Western Michigan 11,500,000,000 "
In Upper Peninsular 19,500,000,000 "
Total 44,500,000,000