8(5 CHLORINE AND IODINE. 



cubic inches of acid gas. Acid of this strength 

 has a specific gravity of 1*1958, and I find, by 

 saturating it with calcareous spar, that it con- 

 tains 40*39 per cent, of real acid, united with 

 59 6l of water! In winter I have obtained mu- 

 riatic acid of as high a specific gravity as 1*212. 

 All the tables hitherto published, exhibiting 

 the strength of muriatic acid of various specific 

 gravities, are very erroneous 5 because they were 

 constructed upon inaccurate data. I conceive, 

 therefore, that it will be worth while to exhibit 

 an accurate table of the specific gravity of this 

 acid of determinate strengths. My method of 

 proceeding was to saturate a given weight of 

 the acid with calcareous spar. Every 6-25 grains 

 of calcareous spar dissolved, indicated the pre- 

 sence of 4*625 grains of muriatic acid. Know- 

 ing the exact strength of one particular acid, it 

 was easy, by the addition of determinate weights 

 of water, to form acid of any inferior strength 

 wanted. I shall exhibit the specific gravity of 

 combinations of one atom of muriatic acid, with 

 a determinate number of atoms of water. The 

 strongest acid I could form, at the time that I 

 was employed in these experiments, was a com- 

 pound of one atom acid, and six atoms water. 

 Its specific gravity was 1*203, and it contained, 

 of course, 40*659 per cent, of real acid. This 

 acid is so volatile, that it can with difficulty be 

 preserved in warm weather. Indeed it frequently 



