( 300 ) 



at the i^ressure p and the temperature t. Then we may deduce 

 from the foregoing law that 



r ^ X r' -\- y r" 



which expression agrees with the one assumed before. It may be 

 remarked that the quantities »■, )■', »•", x and y are taken at one and 

 the same presfjure p and one and tiie same temperature i, and moreo- 

 ver that on account of discrepancies from Daltou's law x-{-y may 

 differ from 1. 



This law of mixtures deduced for gases, agrees, if the molecular 

 rotatory power is considered to be constant, with that which has 

 been adopted l)y Jahn ^), Wachsmuth ^) and oUiers for mixtures of 

 liquids and saline solutions. 



4. Bemlis. Bij applying the above-mentioned law of mixtures 

 we can calculate the rotatory constants cf the pure gases, as has 

 been shown before. The following table gives the coefficients of 

 the formulae 



_ ^1 4_ A - ^V 1 ^ "^M 



(I) 



^2 I ^4 



= ^(' + F 



(H) 



which represent the rotatory constants «, expressed in minutes, and 

 multiplied by 10''. 



1) Jahn. Wied. Ann. 43, p. 284. 



*) Wachsmuth. Wiecl. Ann. 44, p. 380. 



