The Arkansaw traveler., 1888-06-02
Compiled 5Or The ArkaHsQv TrGUeIer. SCIENTIFIC MISCELLANY.

| ana US acceSs0fles In tRe1r various af- fections.
 In some improved English dry plates the developing mixture is fixed to the back of the glass, so that the photographic negative is developed by simple immersion in water.
 The smallest known towering plant, scarcely visible to the naked eye, is Wol6fa microscoptco, water weed of India. Two species of the same genus, the larger about one- twenty fifth of an inch in diameter, grow in the eastern United States.
 One of the chief industries of Bull garia is the production of the ottar of roses. The sheltered valley of Kezan- lyk, known as the Vale of Roses, is is the center of this production, and the product of this district was 100000 francs in 1885. Steps are being taken to encourage the industry in other parts of the Bulgarian terri tory.
 Two French biologists have been making experiments in typhoid fever vaccination. In mice inoculated with cultures of typhoid bacilli genuine typhoid fever seemed to be produced, but in mice inoculated with broth in which the germs had lived but no longer containing them, subsequent inoculation with the most intense ty- | phoid virus was resisted.
 CoLoRING METALs.-By means of a bath consisting of 800 grains of ace- tate of lead, 500 grains of hyposulph- ite of soda and one quart ot water, it is said that eleven different colors may be imparted to well-cleaned copper, and eight to nickel-plated objects. After the salts are dissolved, the solu- tion is heated to boiling, and the metal's afterward immersed therein. At first gray color is obtained, and this, on the immersions being contin- ued, passes successively to violet, ma- room, red, etc., and finally to blue.
 Among the agencies which have helped to build up the peninsula of Florida, according to MT. A. H. Cur tiss, are certain trees, like the man. grove and cypress, which grow on land more or less under water. Like the coral builders, they have worked slowly, but in thousand of centuries the change wrought would be great. It is altogether probable that the thousands of tree- covered "islands' in the Everglades and Big Cypress were once mangrove thickets, and that the present mangrove islands will in time be added to the mainland.
 BASE BALL SCIENCE.-Lovers of baseball may find it convenient to keep in mind this explanation of the pitchers curve from MT. R. A. Proc tor: If the ball is advancing with out spin, or is spinning on an axis lying along it's course, the cushion of compressed air carried forward by it is conical-or rather conoidal-and therefore resists the progress of the ball equally on all sides, affecting only the velocity. But. in the case of the curve, where the bali is spinning on an axis square to it's course, the air in front of the advancing side of the spinning surface cannot escape SO readily as if there were no spin, and escapes more readily on the other side. Hence the resisting cushion of air is thrown toward that side of the ball where the spin is forward, and re- moved from the other side, and the ball is defiected from the region of greatest resistance.
 A NEWLY RECOGNIZED LAw.-Sir William k. Grove has supplemented his familiar doctrine of the mutual convertibility of the natural forces, first announced in 1642, by the prin- ciple of "antagonism." This is traced throughout the natural universe, not as the banetul thing which many deem 1t, but as a necessity of existence and of the organism of the universe, pro- ducing at least as much good as evil. In his recent address to the Royal h. stitution, London, Sir William pointed out that each sun or planet is kept in place or orbit by the an- tagonistic forces exerted upon it that light is affected by antagonism through the troubling of the so-called ether; that antagonism operates in the blades of grass which rob each other of nutriment, in the movements of the heart and lungs, in the battles in the blood between the white cor puscles and the unwholsome bacteria, Tn the competitions and wars of hu- manity, and, finally, in the collisions which must play great part in re- generating life and heat among the cooling bodies of space.
 WHERE WILL DISCOVERY CEAsE?- Whether all science has limits, so that at the present rate of progress all dis coverable things may have become known few generations hence, is a question that must have been sug- gested to many. Concerning the fn- ture of systematic chemistry, Dr. Edward Echunk has concIudod that