540 TRANSACTIONS OF THE AMEEICAN INSTITUTE. 



siders that his discovery will be found very useful. 1. Because 

 chloride of caleiiim saturated witn ammonia is dry powder, easy 

 of transport. 2. Because chloride of csdcium is of xery little 

 value ; and 3, while water will only bold in solution twenty per 

 cent, of ammonia, the chloride will hold tifty per cent, so that the 

 cost of sendisig ammonia a])out will be greatly diminished. 



Peroxyde of Hydrogf-x. 

 Prof. S^hoiibein has discovered a new and very ready method 

 of procuring the peroxide of hydrogen. It consists simply in 

 agitating iu a large flask, to which air has access, amalgamated 

 zinc, in powder, with distilled water» Oxygen is then absorbed 

 by both the zinc and the water, with formation of oxide of zinc 

 and peroxyde of hydrogen. The peroxyde of hydrogen obtained 

 by this method, unlike that obtained by the ordinary process, is 

 quite free from acid, and so may be kept for a long time without 

 decomposition. It does not contain, moreover, a trace of either 

 zinc or mercury, but is absolutely pure. This new process has, 

 therefore, great advantages over the old process of preparing 

 peroxyde of hydrogen, both as being far simpler and more expe- 

 ditious, and as yielding a much purer product ; but it is almost 

 as far as the old process from yielding peroxyde of hydrogen 

 cheaply enough for use in the arts. — [Jlechanics' Magazine. 



Pyrotechnics. 



A correspondent of the Chemical News- says : On looking over 

 a number of receipts, collected among my earlier days of chemi- 

 cal experimenting, I came upon a number of original receipts for 

 colored stars, for rockets, Eoman caudles, and shells, which, as 

 they were the residt of manj' experiments, I can coutidently 

 recommend as very brilliant in color and good, and I venture to 

 hope that not only amateurs, but even some professional pyro- 

 technists may find the receipts serviceable, for even in professional 

 exhibitions some of the colors are often sadly wanting iu bril- 

 liancy. 



The ingredients for each of these stars, for rocket beads, &c., 

 is powdered separately, and then tlie whole is made up into a 

 thick paste, with water, which is rolled out to the proper thick- 

 ness, and punched into square stars and cjirefully dried till quite 

 bard. 



1. lied Stars. — Dried nitrate stroutia, 4; chlorate potash, 2 ; 

 sidphur, 2; black sulphide antimon}^ 1. 



