On disinfectants and their use

ing a nitrate 2 C,,l-i,,iO _\?CJ,, a colorless oil which is immediately decomposed by vvater. ‘lhe explosions of the gases which celluloid evolves under the influence of heat, are probably due to the presence of this nitrate. I’oLoNIUbl. (C’O1/lptc~.$h)L’Jld/1S, l!JIO, I jO.)-Several tolls Of uranium residues yielded z n~illigrannnes of substance containing 0.1 inilligrannne of polonium. l;airly pure helium was isolated from the gases given off by a solution of polonium under a high vacuum in a quartz tube, due to the action of the X-rays emitted by this element. The life of radium is about 5300 times that of polonium (which is reduced to one-half in 140 days). The spectrum is being studied to ascertain if an inactive clement is derivetl from it. I’olonium, according to theory, is the last radio-active term in the series. ON 1)1SINF1’Cl’.\~l’S .\Sl) ‘1’1lLCllub stance sufficiently active upon all the micro-organisms, yet not noisonous, inodorous, and sufficiently soluble. These conditions are partially attained by the halogen derivatives, the chlorides or homides of naphtol, which are more active than most of the known disinfectants, with the exception of corrosive sublimate, and which are practically inodorous and not poisonous. Thus an alkaline solution of tri-bromo-naphtol, of I part in 2jo,ooo, kills staphylococci in two or three minutes, whilst a solution of lysol, of I part in 1000, does not kill them in less than -1.0 minutes. This substance is also very active against streptococci, the bacilli of diphtheria and typhus fever. It gives excellent results for disinfecting the hands.

ELECTRICITY FROM THE WIKD. (Popular Mechanics, April, I~Io.)-When the steam engine reached its development practically the only place where the windmill was retained in service was Holland. But a new use has sprung up for the windmill as a developer of electricity, and it has been re-christened a “ wind-turbine.” In one type of wind-turbine, the wheel of galvanized steel is 16 ft. in diameter mounted upon a steel tower 50 ft. high, ant1 all moving parts run on ball-bearings, and the transmission gear works in an oil bath. The generator used is of about 2 k.w. capacity and of 130 volts. Such a plant costs from $1000 to $1200, according to the size of the storage batteries.