The Arkansaw traveler., 1885-04-25
Compiled for TIE ARKANsAw TRAvKLKR.
 SCIENTIFIC MISCELLANY.

Powell, were the mound builders," and some build mounds to the present day
 The attention of the French Academy of Sciences has been called to a new process of hardening plaster of Paris. The preduc, is recommended for h 'ors, being as durah!s as oak and costing only one-fourth as much.
 It has been observed in Russia that ex. treme cold converts tin into a semi crystalline mass containing large cavities. In one in- stance the pipes of church organ were so altered by cold as to be no longer sonorous.
 The practice of scalping is not peculiar to the American aborigines. Southall in his Recent Origin of Man," quotes from Her. odotus to show that the Scythians used to scalp their fallen enemies. Tn the present time the wild tribes of northeastern Bengal use the scalping knife.
 A new alloy melts at I6o degrees Fahrenheit, or considerably below the tenn perature at which the magical spoons of long ago melted in cup of tea. Its composition is bismuth, 4S; cadmium, B; lead, Io tin, 20. twill stand severe pressure, and is es- pecially adapted to many important uses.
 A remarkable property of the ice-plan,, Dotanically known as "mesembryanthemum crystalinum," is it's ab bsorp,ion of salt, fluid exuded by its leaves having been found to contain about 33 per cent. of sea-salt. Fo, this reason il is suggested that the plant may be advantageously grown on lands made un- productive by an excess of salt.
 l From an ex animation of several skulls found in North and South America, and be, lieved to have belonged to inhabitants living before the glacial period, pr. Kollmann con cludes that the races of that ancient epoch, are those of to-day, the same cranial and fac ial forms being found, in spite of lapse of time and change of environment Several centuries ago the Chinese de- | stroyed their great forests. Abbe David, the l French naturalist, now expresses the belief that they did this to rid themselves of tigers. leopards, and other formidable beasts. An cient forests exist in China only among the mountain ranges, and the plains are so com pletely cultivated that native plants are sell dom found.
 Anim il Vaccination in India.-Pas- teur's system of vaccination for anthrax, of which French farmers have so eagerly availed themselves, has been most successfully tried by the government of India-ponies, don keys, cows, bullocks, buffaloes, elephants, sheep and guinea pigs having been effertu- ally protected against the fatal attaexS of that destructive disease A laboratory for the manufacture of the vaccine !" has been located at Bengal. and, if successful, wifl be followed by similar establishments&in other centres. veterinary surgeon was some time ago sent to study with Pasteur, and it is recommended that others receive similar in- struction.
 Plant Origins.-The laborious investi- gations of De Candolle into the difficult question of the origin of cultivated plants have covered 247 species, of which Io3 are known to be wild at the present day, 27 are classed as doubtful, and a7 others are not found wild at all. There is every reason for believing that at least seven of these last-or nearly three per cent. of the entire number are absolutely extinct That something like three per cent. of the species of pheno- gamous plants," says reviewer of De Can dolle's work, " have become extinct during the historical epoch, and this mot in small islands but on vast continents without any notifications of climatc,' is perhaps the most important general result reached by this investigation"
 Malaria Altitudes.-Whiie malaria be- longs chiefly to low-lying districts. it may. under favorable conditions, exist at great elevations. On the Tuscan Apennines it is found I, 100 feet above sea-level; on the Py- renees and Mexican Cordilleras, 5000 feet; on the Himalayas, 400 feet; on the island of Ceylon. 6, 800 feet; and on the Andes, II,ooo feet. Under ordinary circumstances, how ever, certain moderate altitude affords inn munity from malaria. The elevation of en- tire security is not positively known, but it has been approximated as follows: Tn Italy. AGO to 500 feet; in California, 900 feet: in the Appalachian of the United States. aooo feet; in the West Indies, 400 to I,soo feet in India, 1000 feet. Tn any of these regions malaria may drift up ravines to an indefinite height.
 The Noise of the Javan Volcano.-R.- ports collected since the memorable erup- ton of Krakatoa in August, 1883, have shown that the explosions were heard over a circle of 90 degrees radius. A more astonishing announcement still is now made hy Dr. F. A. Forel, the well known Swiss physicist. He has learned that on the day of the great eruption startling subterranean noises resem- bling the rolling of distant thunder were heard in Caiman-Brac, a small island in the Caribbean sea, near the antipodes of the volcano of Sunda strait. These sounds can not readily be attributed to any neighbor- ing volcanic disturbance, and Dr. Forel is forced to infer that they may have been pro- pagated through the entire diameter of the esrth- To test this bsld hypothesis, inquir- ies are to be made concerning the exact hour at which the detonasions were heard in Caiman- Brac.