416 M. H. Becquerel's Experimental Investigations 



Sulphurous Acid. — This gas was prepared by the volatiliza- 

 tion of liquefied anhydrous sulphurous acid, for which I am 

 indebted to the kindness of M. Raoul Pictet. The gas thus 

 obtained was perfectly dry. It was introduced into the tube 

 which contained dry air. 



In order to analyze this gas, it was, on issuing from the 

 tube, received in small glass tubes which were hermetically 

 closed ; subsequently one of the ends of these tubes was broken 

 over boiled water containing potash, and the gas was analyzed 

 by absorption. By exactly gauging the volume of the small 

 tube as well as the volume of the gaseous residuum not ab- 

 sorbed by the potash, it was ascertained that the mixture 

 enclosed in the tube contained 0*984 of sulphurous acid and 

 0*016 of air. With this gas the following numbers were 

 obtained : — 



Sulphurous acid, 0*984 SO 2 + 0*016 Air. 



Series. 



Average 

 tempera- 

 ture, t. 



Average 



pressure. 



H. 



Correction, , , Corrected 



/i , +\>-ar\ \ observed ; , • 



(l-f-on760 -, ' magnetic 



±-J——ll — . and cor- ,°. 



,. I rotations. 



11 rections. 



Mean 

 devia- 

 tions. 



White light. — 4th image (9 passages). 



July 24, 1880, 





millim. 





, 





250 



819-6 



1-012 



32-12 



Corr. 4-58 



Diff. 27-54 



1 , 



[ 27-87 



37-5 



854-3 



1-012 



34-80 



Corr. 4-58 



I 30-58 



Diff. 30-22 



3rd image. 



2-3 



2-4 



, H 



35-0 



847-2 



1-012 



23-98 

 Corr. 379 



Diff. 20-19 



1 20-43 



23 







Red light. — 3rd image. 







>» » 



39-0 



858-15 



1-012 



22-14 

 Corr. 3-19 



I 1917 



2-3 



Diff. 18-95 







2nd image. 







»5 J5 



44-8 



875-0 



1-012 



16-23 

 Corr. 2-35 



| 1404 



1-9 



Diff. 13-88 



