Aluminium Flashlights

The uso of aluminium injilace of magnesium for the proüuction of flashligbt is strongly advocate! by Professor Glasenapp. He statps that aínnüninin, if einployed in the forru of bronze powdtr, in uot only equal to magnesium as a sonrce of light iu taking phototjraphá by light, but that it is feally much cbeaper than the latter. The foMowing is stated to bo the proper mixture lor the purpose: Aluminium powder, 31.7 parta by wèight; Bulphideof antiinony, 13.8 parts and potasHium ohlorate, G4.5 palts, the same precautions laken in preparing the mixture as in the case of the magnesium flaehlight. In regard to the rapidity of combustión of such a mixture one-sevf-nteenth of a second has been fouud out. Two, gfams of the mixture wero burned in a small heap, a centimeters lon ard a centimeter wide. And in respect of chemical intensity Professor G. atetes that he found by exposing gelatin platea beneath a Warnerke afftinometer to the light of said mixture and to that of other mixtures prepared with magnewn the omTilïcment of enual auantities of the metáis resuíted in a superior light froiii aluininium, thongh not of considerable amount. The speed of combustión is ascertained to be slower- about one-fifth of a secoud- if a mixture is used composed of '0 parts, by weiglit, of aluminium Bowder and 70 p.arts of T:otassinm t