Scientific Notes

A solutian of blue vitriol is used to preserve timber f rom dry rot. A copper wireone-tenth inch thick can support three liundred pound.s weight. To (it a key: Smoke the blank over a eandle. Insert it iuto the keyhole and press it hard against the w'ards oí the lock. The indentations in the amóked portions will show wliere to file. The ownersof all buildings on which lightning rods have stood niany years should occasionally examine them , to see that the earth terminals have not become unsafe by rusting away. Hold a cold chisel iirmly to its cut without removing it at every blow. ThLs will increase the effectiveness o I' the tooi, andthere willbe less danger of breaking by a foul blow. In order to haar distinctly an echo of one syllable the operator must be sixty feet from the surface whieh relects the sound. For echo of iore thaaoné the distance must be over one liundred feet. Lightning struck a calf at Newport, Me., that was covered with white and black spots. Evei-y white spot was smged, even to the taking off of the skin, while not a hair of the black spots was injured. Never allow au embankment of earth subject to freezing to press igainst a basement wall, the successive hrusts of the frost, sooner or latei-, hrowing it over. A vertical stratum ofcoarse gravel or sumll stone shoiild je interposed. In the opinión of M. II. Toussaint no contagions malady has a greater virulence than tuberculosis. The virus preserves its eflicacy at temperaturas which coinpletely destroy the bacteria of splenic fever. Infection takes place as eíusily by indigestión as by inoculaion. It is sometinies necessary toboreone ji' more holes in porcelain, buttheusuil way of doing this is not easy. If, ïowever, an ordinary drill be hardene,d and kept inoist with oil of turpeiiine it will easily penétrate the porceain. The drill comnioniy employed in onnection with scroll-cutting machines inswers very well. Prof. Ilutehinson has, in one of his ectures, mentioned a very intevesting act ascertained in Berlín. Among ioman Catliolics, who prohibit marriages between persons who are near blood relatives, the proportion of deafnutes is 1 in 3,000; aniong Protestants, who view such marriages as permisible, the proportion is 1 in 2,000; vliile among Jews, who encourage inermarriage With blood relations, the deaf-mutes are as 1 in 400. F on Sleep lessness. - Wet half a owel, apply it to the back of the neck, ressing it upward toward the base of he brain, and fasten the dry half over o as to prevent the too rapid exhalaion. The effect is prompt and charmng, cooling the brain and inducing almer, svveeter sleep tlnui any narcotc. Warm water niay be used, though lost persons prefer cold. To those who suffer frouiover-excitement of the jrain, whether the result of brain work r pressiug anxiety, this simple remedy ïas pro ved an especial boon. Every boiler should be protected 'rom the weather. It often occurs liat boilers have no other proteetion han simply a loóse board roof, whïch n ordinary rain stornis leaks at every oint. If the boilers vvere always uner stf am, the bad consequence woukl je comparatively light, but the great mischief occurs when the boilers are old. Whenever rust appears on the irface of a boiler it means loss of iron and strer.gth, and eonsequently is less able to witlistand high presare. A novel pair of scissors has been ievised by Ilerr Sievert of Dresden. j lie Diaaea are representen oy two ciralar steel knives,. which slightly overap at the edges, and ire pressed to;etker by two spiral springs. The cni ves are Í astent d to a pair of vvooden rollers with India rubber rims, vhich grip and galde the clotli as il asses between the Unives, so that the atter may cut straight. These cutters are carried by two handles, or levers, which are held in hand, and the cnt,ing is eft'ected ly pushing the scissors brward, so as to cause the rollers io evolve. .Large iron ore deposita ofahnost unirecëflentëd richnesa have lately been urveyed in Lapland by practical minng engineers. The district is near the 'illage of Jukasjarvi, in Swedish Lapand, about 10 miles froni ohe ol the anns of the AVest Fjord. Analysis hows 70 per cent. of metallic iron iu his ore, and the quantity is sai ■ to be ufflcient to supply the entire world with iron, at the present rate of conuini)tion. for many years. It is inended to construct a raihvay trom Fajernaes to the mine; aud it is stated hat the attentionof Eagliahand Dutch ■apitalists has already been directed to he valué of the ore by 011e of the Swedsh authorities. The Journal of Science says that in order to account for the mysterious liaappesrances of persons, nowso eomnon, a Frenen writer suggests the exstence of a disease not yet reeognized, which, without any previous warniiig, uddt'iüy resolves the patiënt into vaor. lle even professes to have witïessed the disappearauoe of a friend with wliom he was walking. A very imple consideiation overturns this hywtheais. We can scarcelyassuinethat hediseasi? causes the südden vaporizaion of clothing, boots, keys, knivea, noney, trinkets, and all that the patiënt uul about him at the time of his disapearaiice. Yet no one has ever foiuid n the street a complete suit of clothes rom which the body of the wearer escaped. A cheap and useful disinfectant is a olution of chloride of lead. It is modorous, efïective, and its cost very mail. It inay be prepared as follows: Cake half a drachni of nitrate of lead md dissolve in a pint or more boiling vater. Dissolve two drachms of coinnon salt in a pail or bucket of water, )our the twosolntions together, and alow the sediment to subsidë. The clear upernataut fluid will be a saturated olution of chloride of lead. A cloth ipped in a solution of chloride of lead nd hnng lip in a room will sweeten a 'etid atmosphere instantaneously, or ie solution thrown down a sLuk, waer-closet, or drain, or over a heap of efuse, will produce a like result.