78 CHLORINE AND IODINE. 



v 



tween the atomic weights of chlorine and hy- 

 drogen. 



Srrit^of Now, I took the specific gravity of this gas 

 chlorine three times successively, and found it always 

 1-500.* Many other considerations lead to the 

 conclusion th#t this is very near the truth. Of 

 these it may be sufficient to mention the fol- 

 lowing : 



1. The specific gravity of muriatic acid gas 

 was found by me from an average of three ex- 

 periments, to be 1-284366. Now, the specific 

 gravity of this gas is a mean between that of 

 chlorine and hydrogen gases. Let 



x = sp. gr. of chlorine gas 

 a = sp. gr. of hydrogen gas 



We have -+-" = 1-284366. Consequently 



x 2-568733 0-0694 = 2-499333. 



Now, 2-499333 is only irrVr part less than 2-5. 

 This is a coincidence between the two experi- 

 ments as near as the nature of the apparatus 

 employed will admit of. 



2. Gay-Lussac, in a table inserted in the first 

 volume of the Annales de Chimie et de Physique, 

 states the specific gravity of chlorine gas to be 

 2-470. Now, if his experiments were made witli 

 gas prepared over water, as was undoubtedly 

 the case, his result approaches very nearly to 

 mine, if we estimate the specific gravity of the 



* Annals of Philosophy, xvi. 169. 



