Collodion As A Generator Of Electricity

Professor Gut line has soinn time finco utilizad i He mixture of collodion and India rubber for this purpose, andalso givon it a wider scope. As reirards eTectricity, it is very remarkable that if yon rub glass witii the slieot of India rubber and collodion, negatire eleetrieity Ís oxcitat, where, ordinarily speakinsr, positivo electricity, is generaled. One of the applications the Professor has íiven to this collodio-caoutchouc is tho fornrvtiou ot miniatura balloons for exjwrhnontal purposes. An ordin u y glass Üisk is íirst coatcd inside with collodion by rolling the liquid round and round iiiside. When dried, a layar of Indiarubber is given to the collodion iu the sanie way, a t thon anotlier layer of collodion, and so on, till four or five thickuosses of collodion are reached. When dried, tho lilm is euelly detaclied by lifting it at Uie neck of the llask, and pouring between it and the glass a littlo acululatotl water. iuc balloon then comes out perfeotly vrell shaped, iiml reiuly tu bu iilled with any gas wbioh it may bc desired to try, and the neek: is woll seeured by waxed silk or any otber suhable ïneans. In experimental physios tbcre seem to be maiiy applicatioua of tbis medium, and üo doubt it will come in lo use. It may bc used, says the Photographio News, to tie down tbe stoppers of bottles ; and here its pliability is of great service, as tliero is none of tbat disMgreeableness in opeuiug a stoppered bottle wliich has bsen tied down with an ordinary bladder. - Phutographers liave belbre now brought into prominence sonie proporties of different material wliosu value had not been previously reeogUlZOd.