C. ELECTRICITY, LIGHT, HEAT, AND SOUND. 43 



and malleable metal, which decomposes water readily below 

 the boiling point, and oxidizes very rapidly. 1 A, Septem- 

 ber 23, 155. 



IMPROVED ELECTRIC AMALGAM. 



It is well known that a deposit of moisture greatly inter- 

 feres with the action of electrical machines, experiments often 

 wholly failing from this cause, especially in the winter sea- 

 son. Mr. F. Dietlen, of Klagenfuit, has devised a method by 

 which he obviates this difficulty, consisting simply in a modi- 

 fication of the amalgamation of the rubber cushion. For this 

 purpose he pours petroleum over zinc filings, and adds an 

 equal quantity of mercury (though an excess of mercury fa- 

 cilitates the process). The mixture is then brought, by work- 

 ins; together in a mortar, to the condition of a homogeneous 

 paste, and pressed between a double cloth. A soft mass is 

 thus obtained, which, however, soon hardens ; but which, be- 

 ing finely pulverized and mixed with a proper quantity of 

 grease, is spread upon the rubber cushion. This makes the 

 surface quite glossy, and, when the glass disk has previously 

 been wiped with a piece of cotton slightly impregnated with 

 petroleum or benzine, will act even in damp localities where 

 the usual arrangement fails. 9 C\ 1871, in., 20. 



DEVELOPMENT OF OZONE BY THE BATTERY. 



Professor Boettger informs us that if a solution of nitrate 

 of bismuth be decomposed by the galvanic current, an un- 

 commonly large amount of ozone is developed at the pole 

 connected with the platinum element, while the platinum it- 

 self becomes coated with a layer of superoxide of bismuth at 

 the same time. By a similar treatment of a silver or lead salt 

 there is a like deposit of superoxide of these metals, but with- 

 out any special development of ozone. 15 C, 18*71, xx., 320. 



CELESTIAL ORIGIN OF POSITIVE ELECTRICITY. 



M. Becquerel has recently presented a memoir to the Acad- 

 emy of Sciences of Paris upon the celestial origin of atmos- 

 pheric electricity, or rather of the positive electricity distrib- 

 uted in enormous quantities in the planetary spaces. This 

 he finds in the hydrogen electrized positively which escapes 

 continually from the sun. According to modern observa- 



