Haughton — Notes on Newtonian Chemistry— V. 303 

 The most probable constants of (SiH) are 



?Wi = - 13, [i = 28, 



r' = 1-0501, 0)'^ = 1-02061, 



(o'V = 1-07176, //? = + 1-2678, 



MEMORANDUM ON THE LAW OF AVOGADRO. 



The weight, specific gravity, and volume of a body are connected 

 together by the simple equation, discovered by Archimedes, 



"Weight = specific gravity x volume. 



If we suppose that in a given volume of a gas, we have N mole- 

 cules, or separate systems, the preceding equation may be written, if 

 we call M the weight of the molecule (proportional to the atomic 

 weight), and S and Fthe specific gravity and volume of the gas 



Jfx N = SxV; 

 or. 



Now, the Law of Avogadro states that 

 M Molecular weight 



= Constant : 



S Specific gravity of gas 

 therefore, as V is constant, N is constant, or 



In a given volume of chemical gas, there are always the 

 same number of molecules. 



The following Table contains the data on which the Law of 

 Avogadro is founded : — 



[Table, &c. 



