74 8 



NUMERICAL CONSTANTS. 



CHAPTER II. 

 NUMERICAL CONSTANTS. 



1290. CHEMICAL ACTION. Experiment shows that a coulomb 

 or an ampere per second reduces rii73mgr. of silver and decom- 

 poses 0-093 i6mgr. of water (918); it follows that for the 



ACTION OF AN AMPERE. 



Silver reduced Ag=io;'93 



Copper , Cu= 31-98 



Water decomposed HO= 9*0 



Hydrogen H= I'D 



Volume of Hydrogen at 76cm. and 0. 

 ,, Detonating Gas .... 



1291. RESISTANCES. All the following resistances are arranged 

 in reference to the legal ohm. If we assume that the resistance 

 of io 9 C.G.S. units were represented by a column of mercury of 

 106 '2 5 cm. instead of 106 cm., we should multiply the conduc- 



106*25 

 tivities by the ratio _ = 1-0024 an d divide the resistances 



by the same number. 



106 



METALS AND ALLOYS. 



Nature of 

 Conductors. 



Silver annealed 

 ,, hard drawn 



Copper annealed . 

 ,, hard drawn 



Gold annealed 



hard drawn . 



At the Temperature of 0' 



Value in C.G.S. Units. 



Resistance in Ohms. 



