Intelligence and Miscellaneous Articles, 471 



III. Water and sulphuric acid. 



Water. Sulphuric acid. 



1st thermometer 63 C. 65*7 C. 



2nd thermometer 31 32 



3rd thermometer 22*75 23 



External temperature . . 16 16 



The quotients q are 2*74 for water, 2*77 for sulphuric acid; so 

 that water conducts a little better than sulphuric acid. 



In order to compare also a more concentrated solution of sulphate 

 of zinc with water, I put the apparatus together again, and investi- 

 gated mercury at the same time. 



IV. Mercury, water, sulphate of zinc. 



O " n 



1st thermometer 82 C. 



2nd thermometer 65 



3rd thermometer 50*8 



External temperature . . 16 



The quotients (q) are 2'04 for mercury, 2*57 for water, and 2*64 

 for sulphate of zinc. 



To calculate the ratios of the conducting-powers of different liquids, 

 the quotients 



should have been constant, which, however, is not the case, as the 

 first Table shows. At any rate, a greater number of equally distant 

 thermometers should have been used as a control. 



I content myself, in conclusion, with arranging the liquids in series 

 in which the best-conducting precedes. 



Conducting-power for — 



68 C. 



65 C 



36-2 



32-5 



25 



20-2 



14 



15 



Electricity. 

 Mercury. 

 Sulphuric acid. 

 Chloride of sodium. 

 Sulphate of zinc. 

 Sulphate of copper. 

 Water. 



Heat. 

 Mercury. 

 Water. 



Sulphate of copper. 

 Sulphuric acid. 

 Sulphate of zinc. 

 Chloride of sodium. 

 Poggendorff's Annalen, No. 8, 1868. 



MOLECULAR CHANGE PRODUCED BY MAGNETISM IN STEEL BARS. 

 BY M. TREVES. 



More than twenty years ago several physicists, among others 



