Scientific Notes

Tea vrood is excellent for building purposes. Spirits i eamphor mafcea a goud barometer, as it is cloudy before a storm and clear in fair weather. It is n popular mistaketo cali a thin, Haky, semi-transparent mineral isinglass. Isinglass ig a li.sh glue and has nothing to do witli the mineral, wliich is mica. What are the elïects of different kinds of intellectual work on the cerebral circulation 't ïhis question M. Gley, a French physiologist, has attempted to answer by experiments made upon himself. When he applied liirnsclf to a subject which he had a difflculty in understanding thoroughly, and had, therefore, to concéntrate all liis energie upon it, the rhyUnn of the heart was far more accelerated thau when ho took up some matter with which he w;is well acquainted. The force required to drive a spike and to pull it out are as nearly as may be equal with hard woods, it being often the case that considerably more dead load is required to push out the spike tlian to drive it in. Ontlie other hand, with the sof ter woods the force. required to drive the spike is about one-iifth greater. It is a peculiariiy which laay be frequently noticed taat a spike which has required t greater force than another to diive it into the same wood will require less lorce to drive it out, and vice versa. "Petroleum is found to be of benefit to shingles to preserve theiu, as it enters the poresof the wood at onee, and 38 it haxdeos, makes it more compact ui texture, and al.su ruiker less liable to take lire, althougli wlien once burniiif,' they vvill of come produce more flaroe tban tlie wood without it; but a eoat of petroleum applied toa sliingltroof will inakc it laat severa] years lopger than it othervvise would. Petroleum is aldo au excellent article to ap3ly to the. iron and steel w#rk of farin implements to prevent their rustiu when not in use. A beech tie, if effectually preserved from rotting, would be a better tie thíin white oak; and a red or pin oak tie about as good. Elm, black and whiie asb, if efl'ectually preserved, will hold a spike about two-thirds aswell as beecb or oak and about one-thirdbelter than chestnut. Soft maple and sycamore hold a spike about íüur-íiíths as well as chestnut, about two-flftha as wiill as oak or beech, and about oneht.lf better than hemlock. Seasoned white oak is about one-third less effeeí.ive than green tiniber in a spike. Prof. Pasteur's address on animal vaccination and bis experitnents are attracting great attention among European stock raisers, who in Franee alone are said to lose no less than $4,000,000 worth of live stock a year from splemc f e ver. In one demonstraron 50 sheep wero moccuiateü witn virulent anthracoid microbe. Twenty-rive of them had been vaccinaced and sliowed no ill effect froin the infection, but everyone of the 25 which were unvacoinated died from splenic fever. So successful ha.s the new discovery been that demauds for stock vaccination are too numerous to be attended to, and in the neighborhood of Paris alone, within a inontli, 30,000 sheep and immense numbers of cattle have been operated upon. The inventor of a patent life-preserver undertook to give a personal exhibition of its merits in the Delaware nver. He put it on, and tlien boidly juinped into the water, butto the astenishuient of the numerous spectators, the bold inventor cauie up iïom his dive f eet foremost, and reniained so, in a position not at all conducive to a prolonged existence. His head went uüder a:ui stayed there until he was rescued. During the excitement two men and a boy feil into the river, and carne near being drowned. The inventor explained that he had put the air belt on in the wrong place; bat he did not offer to repeat the experiment. As people who wish to use life-preservers usually have no time to spare while putting them on, and as the prop r way to save life is to have the head out of water, the Philudelphia invention can liardly be recommended to oautious travellers.