Chemistry and Physies. 215 
tation of the apparatus used by M. Caillelet in his experiments 
described in our last number. Sie Oy BR 
10. The effect of Light and Heat upon the electrical resistance 
of Selenium.—W. Stwmens has undertaken a long ecg upon 
i at it 
scale, but without much success. He hopes, however, that other 
observers with better means may be more successful.— Amn. der 
Physik und Chemie, No. 12, 1877, p. 521. J.T. 
12. On Electromagnetic and Calometric absolute measurements. 
—Prof. H. T. Weer in a paper not yet concluded, discusses the 
various results, obtained by different observers for the value of 
’ resistance unit, and concludes from three independent 
Wilh. Weber, F. Kohlrausch and L. Lorenz, are a ted with 
rs of observation. Prof. H. T. Weber finds for the value of 
e 
Siemens’ resistance unit the expression 
1S. M. U, = 0-950 x 101°( 
Weber concludes his first paper as follows :-— : 
“(1.) The fundamental ee itherto recognized of induced Se? 
rents of variable intensity represent with great precision the : 
facts. The opinion of M. Lorenz, that the B soo difference | “i 
tween the results found by M.M. Weber, F._ ohlrausch and the 
physicists of the British Resistance Committee was the conse 
— 
. 
me) 
sec 
