The Arkansaw traveler., 1889-09-14
COMPILED poR TIE AnKAxskw TRAvnExR.
 SCIENTIFIC MISCELLANY.

AmpIfE3t fsssou and teachsrs all but sixtesn being Japanese This years students number 7Ss.
 The antiseptic properties of Accharine make 1t an effective wAsh for the mouth and teeth when dissolved in water, according to . French wTitsr six per cent. solution s used, but a strength Of only one In 500 is said to prevent fermentation or spelling of mucilAge, etc.
 ELECTRIC CooKno.-The electric current used at night for lighting hotel at sAmAden is now put to during the day for heating the kitchen range Resistance coils of German silver are brought Co rcd heat by the current, and make it possible to perform all the ordinary cooking operations with out fire. The electricity h generated by power from waterfall.
 PorATo CULTURK.-Dr Gilbert hes learned from twelve years of experiment ct Rothamsted that potatoes require due proportion of nitrogenous and mineral food, as has long been held by good farmers, and that mineral manures alone produce little result. The liberal of barn. yard manure seems to Dc justified by the large yield, which is thought to offset the disadvantage of greater liability to diseAse Continuous growth of potatoes in the same land appears to render the crop les liable to disease instead of more %.
 PERIODICAL INcENDIARIsM.-The prevalence of incendiarism is found by MT. Franklin Webster to vary with the Tn the four years ending with 1886 there were more criminal fires In January than In February, an increase in the number through March, April and May, falling of In June, further increase s=t. November, ss4 s!!- ing of again In December. The number showed remarkable regularity for the first half of the year, while In the second half it was much greater but much more nuctuating. In farming districts in- cendiarism was most frequent in busy periods, especially at harvest.
 A METEOROLOGICAL MYsrERY-A remarkable air wave of January 3l has attracted much atten- tion from meterologists, who are still unable to explain the phenomenon At several stations in Central Europe the barometer recorded . sudden dip of about four hundrefths of an inch, followed by corresponding rise few minutes later. Dr. E. Hermann has traced tho disturbance from Pola to Keitum, separated by about five degrees of latitude, the rate of trAnslation between these places having been about seventy -one miles hour. In easterly and westerly direction the disturbance was confined to narrow limits. There was no earthquake in Europe.
 THE FINEST FIBREs An ordinary hair Is about one 5OOth of . inch in diameter. In his delicate measuring instruments, MT. c. V. Boys, F. R. S., has made use of quartz flores from one 5,OOOth to one l0,000th of inch In diameter, supporting weights of thirty grains In his experiments quartz fbres much finer than this were drawn out by means of an arrow from . cross-b bow, the diameter of some being estimated to be lees than one millionth of an inch. Such threads are, of course invisible, and recommended a test for micro scopes To give an idea of such degree of minute
 ness Mr Boys remarks that . piece of quartz an inch long and an inch in diameter would, If drawn out to this hneness be sufficient to go all the way round the world e5S times, or grain of sand just
 vsible-that is, one hundredth of an inch long and one hundredth of an inch in diameter make 900 miles of such thread.
 THE AIR. Machines for navigating the air may be divided into three classes-nying machines without gas bags, ordinary balloons propelled by the wind alone and air ships of gas envelope and car containing propelling machinery. The idea of combining the flying with the balloon, affirms MT. J. K. Watkins contains, in the opinion of modern aeronAuts the one element of hope for the future for successfully navigating the atmosphere. To meet the views of this author, the practical air ship must be substantially constructed, must Dc provided with life boats and parachutes, must have light and powerful engines with reserve set for accident, must have ample generators for making gas route, must have . rigid gas- envelope of form to offer the least resistance to