60 Analyses of Books. [July, 



entered, I think, without sufficient consideration. He has given 

 the number of atoms which combine in several instances in his 

 Comparative View. Thus water is composed of one atom of 

 hydrogen and one of oxygen, and sulphurous acid of one atom 

 sulphur and one atom oxygen. Now he affirms that his numbers, 

 where he has given them ; namely, the constituents of water, sul- 

 phurous and sulphuric acids, sulphureted hydrogen, and the com- 

 pounds of azote and oxygen, are more accurate than those given 

 by modern chemists ; for example, he still insists upon it that sul- 

 phurous acid is a compound of 1 atom sulphur + I atom oxygen, 

 and sulphuric acid of 1 atom sulphur + 2 atoms oxygen. Now if 

 this be true, an atom of sulphur and an atom of oxygen have the 

 same weight, and these two acids are composed by weight of the 

 following proportions : — 



Sulphur. Oxygen. 



Sulphurous acid 100 + 100 



Sulphuric acid 100 + 200 



Now there cannot be the least doubt that sulphuric acid is com- 

 posed of 100 sulphur -f- 150 oxygen, proportions totally irrecon- 

 cilable with his determination. 



I have dwelt so long upon this controversial subject, that I have 

 only room slightly to notice those parts of the work which are 

 original. The electrical hypothesis consists in supposing that, as 

 electricity passes through bodies, it displaces their specific heat. 

 Hence the electric light. Those bodies which have but little heat 

 are non-conductors, as is the case with glass ; but when glass is 

 heated, it becomes a conductor, in consequence of the heat thrown 

 into it. If this hypothesis were correct, the metals ought to be 

 non-conductors, for they have very little specific heat ; and water 

 and hydrogen ought to be the best conductors in nature, as they 

 have the highest specific heats. This hypothesis, I fear, would not 

 stand the test of the slighest examination. 



The original experiments relate chiefly to the proportion of 

 oxygen necessary to consume completely a given bulk of sulphureted 

 hydrogen ; but the sulphureted hydrogen used by Mr. Higgins was 

 of necessity impure, as he procured it from sulphuret of iron ; at 

 least I have made numerous experiments on the subject, and never 

 yet extracted sulphureted hydrogen from artificial sulphuret of iron, 

 without finding it mixed with hydrogen gas. I have in some cases 

 found the proportion of this last gas GO per cent., and seldom less 

 than 10 per cent. Hence experiments with gas prepared in this 

 manner are not entitled to confidence. Crude antimonv and 



J 



muriatic acid, when heated together, yield sulphureted hydrogen 

 perfectly pure. It ought, therefore, to be always prepared in that 

 manner for experiment. 



It is easy to determine from theory how much oxygen gas is re- 

 quired to consume a given bulk of sulphureted hydrogen gas, sup- 

 posing the sulphur to be totally converted into sulphurous acid, 



