NATURAL PHILOSOPHY. 129 



Now as one-quarter of an ounce of zinc requires only 0.06 of an ounce 

 of oxygen to form oxide of zinc, Mr. Kukla draws the conclusion that 

 the rest of the oxygen is converted directly into electricity ; and this 

 view, he says, is confirmed by the large amount of electricity given 

 out by the battery in proportion to the zinc consumed in a given time. 

 In the above battery each zinc plate had a surface of forty square 

 inches. The addition" of per-oxide of manganese does not increase the 

 effect of the battery, but it makes it more lasting; the per-oxide of 

 nitrogen, formed in the bell-cover, taking one atom of oxygen from 

 the per-oxide of manganese ; this is evident from only the oxide of 

 manganese being found in the battery after a time : in the salt solution 

 no other alteration takes place than what is caused by the oxide of 

 zinc remaining in a partly dissolved state in the solution. For this 

 battery Mr. Kukla much prefers porous cells, or diaphragms of biscuit 

 ware, as less liable to break, and being more homogeneous in their ma- 

 terial than any other kind. This battery is very cheap, antimony be- 

 ing only 5d. per lb., wholesale, and the zinc not requiring amalgama- 

 tion. The second arrangement tried by Mr. Kukla was antimony and 

 amalgamated zinc, with only one exciting solution, viz. : concentrated 

 sulphuric acid. This battery has great heating power, and the former 

 great magnetizing power. It, however, rapidly decreases in power, 

 and is not so practically useful as the double fluid battery, which will 

 exert about the same power for fourteen days, when the poles are only 

 occasionally connected as in electric telegraphs. Certain peculiarities 

 respecting the ratio of intensity to quantity when a series of cells is 

 used, have been observed, which differ from those remarked in other 

 batteries. Mr. Kukla, on directing his attention to the best means of 

 making a small portable battery for physiological purposes, has found 

 very small and flat Cruikshank batteries, excited by weak phosphoric 

 acid (one of glacial phosphoric acid to twenty of water), to be the 

 best. Phosphoric acid being very deliquescent, and forming with the 

 zinc, during the galvanic action, an acid phosphate of zinc. A bat- 

 tery of this description does not decrease in power very materially 

 until it has been three hours in action. 



THE AURORA BOREALIS AND THE ELECTRIC TELEGRAPH. 



A correspondent of the Boston Traveller furnishes the following 

 results of six years' experience in determining what effect the Aurora 

 Borealis exerts upon the telegraphic wires. 



On the House, Morse, and other magnetic telegraphs, the effect 

 produced by the Aurora is generally to increase or diminish the elec- 

 tric current used in working the wires ; sometimes it entirely neutral- 

 izes it, so that in effect no fluid is discoverable on them. As, however, 

 the Bain, or chemical telegraph, is much the best adapted for observing 

 the precise effect produced by the Aurora, I shall confine myself* 

 principally to it. In this system, the main, or line wire, is brought 

 into direct contact with the chemically prepared paper, which lies on 

 a metal disc, connected with the ground ; any action of the atmos- 

 pheric current is therefore immediately recorded on paper 



