242 



Dr. Andrews on the Heat developed 

 39. Table IX. — Peroxide of Mercury. 



ACID, 



FOUND. 



Nitric, . . 

 Acetic, , , 

 Hydrochloric, 

 Hydrocyanic, 

 Hydriodic, , 



1°,20 

 1,20 

 3,80 

 5.85 

 9,20 



2' 

 2 

 2 

 2 

 3 



CORR. TIME. 



0°,05 

 0,05 

 0.20 

 0,25 

 0,60 



CORRECTED, 



r.27 



1,27 



4.65 



7,10 



11.40 



40, To the last number some objection may be made, as a large excess of 

 hydriodic acid was used to prevent the formation of the Insoluble perlodlde of 

 mercury ; but even if we omit it altogether, the other parts of the table exhibit 

 singular discrepancies. It is probable that a more extended investigation will 

 discover other metallic oxides, resembling the peroxide of mercury, in yielding 

 different quantities of heat, when they combine with the hydraclds, 



4 1 , The hydrocyanic acid stands not less apart from the other acids than the 

 oxide of mercury from the rest of the bases, in its development of heat when 

 forming compounds ; and it is remarkable that no analogous property appears 

 with the hydrochloric and hydriodic acids. The hydrocyanic acid used in these 

 experiments was perfectly pure : it was employed immediately after being 

 rectified over chalk, and had no action on vegetable colours, I have collected 

 together the elevations of temperature produced by it, and contrasted them with 

 the mean quantities of heat given by the other acids with each base. 



