MOLECULAR VOLUME 



677 



The rule C : H = 4 : 1 has been traced from the Critical to the 

 Melting Point or throughout the liquid state. 



According to the Prideaux's result it should also be noticed 

 at the Boiling Point. 



We cannot doubt that at absolute zero the relative volumes 

 of bound C and H is as 4 : 1 in each compound and approximately 

 for different compounds. 



Similarly, it is probable that a constant relation exists 

 between the volumes of other atoms. 



It is to be expected also, that additive relations exist in the 

 volumes of the Sn-Pb alloys in both the solid and liquid states. 



The Additive Ride in the Sn-Pb Alloys near the Melting Point 



Pb 18-259 

 Pb 18-565 

 Pb 18-818 

 326 C. 



We note from the above table that the additive rule holds in 

 the three conditions above mentioned — one in the liquid, and 

 two in the solid state. 



Expansion in both states takes place owing to the increase 

 in the spheres of activity of the atoms, and there is no reason to 

 suppose that any change in this respect occurs owing to change 

 of state. 



On comparing the atomic volumes in the free and combined 

 states, we see that they are nearly the same at the same 

 temperatures. 



