on the Atomic Weights of Bodies. 253 



perimental result, rendering it exceeding probable, that the 

 number which we have pitched upon for the atomic weight 

 of these bodies is indeed very near the truth. In the 

 specific gravities of the vapours determined by Mitscher- 

 lich, the coincidence between the calculated and experi- 

 mental results is not so close. Because, from the high 

 temperature at which these specific gravities were taken, 

 sometimes as much as 643° ; it was impossible to attain the 

 same accuracy, as when the specific gravity is taken at the 

 common temperature of the atmosphere. Nor, is it quite 

 clear, that the corrections for the temperature which Mits- 

 cherlich applied are perfectly correct. 



III. Gases whose sp. gr. = atomic weight x 1*1111- 



Specific Gravity, 

 Atomic 



weight. 



1 



By ex- 

 periment. 



By cal- 

 culation. 



1-1117 1-1111 



Oxygen, 



IV. Gases whose sp. gr. = atomic weight x 2-2222, or 

 twice the specific gravity of oxygen gas. 



Specific Gravity, 

 Atomic 

 weight. 



Phosphorus, . . 

 Arsenious acid, . 



2 



6-25 



By ex- 

 periment. 



4-6* 

 13-85* 



By cal- 

 culation. 



4-4444 

 13-8888 



V. Gases whose specific gravity = atomic weight x 2-5, 

 or 2^ times the specific gravity of oxygen gas. 



Arsenic, 



Atomic 

 weight. 



Specific Gravity, 



By ex- I By cal- 

 periment. culation. 



4-25 1 10-6f 1 10-625 



VI. Gases who sp. gr. = atomic weight x 3-3333, or 

 3 times the specific gravity of oxygen gas. 



Specific Gravity, 



Atomic 

 weight. 



Sulphur, 



By ex 



periment. 



6-9: 



By cal- 

 culation. 



6-6666 



* These specific gravities were determined hy Mitscherlich. — See Poggendorff 's 

 Annalen, xxix. '218 and 222. 



t Mitscherlich.— Ibid, p. 819, 



t Ibid. p. 217. 



