376 Dr. A. Naumann on the Velocity of Atomic Motion. 

 and therefore, for any other atom, 



*/' = 0-8165 . 485^/ (274-6 + gg" B 

 V 274-6 . 0-0692N" 



N' 



tti however, is also the ratio of the atomic weights; and since 



N ; 1 

 the atomic weight of hydrogen =1, we have z— T = ~ . Conse- 

 quently, if N represents in general the atomic weight of any 

 simple body referred to that of hydrogen as unity, the velocity 

 of an atom of this body in gaseous compounds is represented by 



v t = 0-8165. 485 m \f 274 ' 6 + * . . (3) 



V 274-6. 0-0692. N V ; 



For 0° C. this equation becomes 



v = 0-8165. 485 m xf L___ = 



V 0-0692. N 



396* 



VO-0692 . N 

 1506 m 



= w ■ • • • • w 



Thus, for example, the velocity of an atom of carbon at 0° in a 



gaseous compound (such as marsh-gas, C H 4 , or ethylene, C 2 H 4 ) 



would be 



1506 m , QKrri 

 v () = — -==- =435 m . 

 \/12 



Equation (3) expresses that the same atom possesses in all its 

 gaseous compounds the same velocity, and consequently the same 

 intensity of vibration, at the same temperature. The same equa- 

 tion expresses further that the velocity or intensity of vibration is 

 directly proportional to the square root of the absolute tempera- 

 ture, and inversely proportional to the square root of the atomic 

 weight. 



There is as yet no conclusive reason for supposing that the 

 velocity of the motion of the atoms in a molecule of liquid or 

 solid bodies is different at the same temperature from what it is 

 in gaseous bodies ; and therefore it cannot for the present be as- 

 serted that the application of equation (3) to the atoms of liquid 

 and solid bodies also is inadmissible. 



Giessen, March 5, 1867. 



