C. W. R. POWELL. 



Three experiments were carried out with the steel 

 mentioned, and the analyses of gases evolved at 30° O. show 

 approximately the same ratio of S0 2 to hydrogen. 



Experiment I. 



Time in days. 



Temperature °C. 



so 2 



H 





10 



40 



30 

 30 



5-5 



4-9 



94-5 

 95-1 



100-0 

 100-0 



The first column in the table expresses the time the 

 reaction has been proceeding, and the second records the 

 temperature at which the sulphuric acid was maintained. 

 In Experiment I, 19*405 grams iron were immersed in 

 about 60*0 c. cms. of concentrated H 2 S0 4 . 



Experiment II 



Time in days. 



Temperature °C. 



S0 2 



H 





18 



30 



2-0 



98-0 



100-0 



32 



30 



6-3 



93-7 



100-0 



54 



30 



4-9 



95-1 



100-0 



3 



35 



7-5 



92-5 



100-0 



6 



35 



8-0 



92-0 



100-0 



8 



35 



6-8 



93-2 



100-0 



12 



40 



10-5 



89-5 



100-0 



In this table column one expresses time for each tem- 

 perature, starting from zero again every time the temper- 

 ature was changed. 17*906 grams iron were in this 

 experiment immersed in about 60*0 c. cms. of concentrated 

 sulphuric acid. 



Experiment III 



Time in days. 



Temperature °C. 



so 2 



H 





8 



19 

 25 



25 



30 

 30 



3-2 



7-3 



7-7 



96-8 



92-7 

 92-3 



100-0 



100-0 

 100-0 



