Mr Daltotfs System of Chemical Philosophy. 349 



ing them for this purpose. Indeed we cannot help regretting that the 

 author of the most important discovery which has ever enriched chemistry 

 should not have partaken of the feeling of the illustrious author of the 

 Novum Organon, who complained that " he, who deserveth to be an archi* 

 tect in this building, should be forced to be a workman and a labourer, 

 and to dig the clay and burn the brick ; and to gather the straw and the 

 stubble all over the fields to burn the bricks withal." Mr Dalton could 

 not indeed, like Bacon, complain that there were no workmen, and that, 

 *' unless he do it, nothing will be done;" for all in all the labourers are 

 not few ; and we cannot but feel, that, if he had employed himself (which 

 obviously he has not) in overlooking their labours, he would have stood 

 more in his place ; and he, who ranks low among workmen, might, as an 

 architect, have continued to add beauty and stability to the edifice of 

 which he was the projector. With regard to new facts, Mr Dalton's work 

 does not furnish many ; yet various statements scattered up and down 

 will repay an attentive perusal. We shall take notice of one or two of 

 these, which, however, are not absolutely new. 



In dissolving mercury in aquafortis, Mr Dalton says that no gas is evolv- 

 ed in the cold. Without having experimented on the subject personally, 

 we may remark that it is quite possible that by this means a mixture or 

 compound of one atom nitrate and of one atom hyponitrite of mercury may 

 be produced. Thus two atoms nitric acid 13.5 (= 3.5 of axote + 10 oxy- 

 gen, according to Dr Thomson) may resolve themselves into 6.75 (one atom) 

 of nitric acid + 1. (one atom) of oxygen = 7.75, and into 4.75 (one atom) 

 of hyponitrous acid + 1. (one atom) of oxygen = 5.75 which, added to 7.75 

 gives 13.5, the two atoms of nitric acid. From Mr Dalton's highly valu- 

 able paper on the action of nitric oxide on oxygen over mercury,* it is easy 

 to gather that two volumes of nitric oxide form with one volume of oxygen 

 one volume of nitrous acid ; which volume of nitrous acid is absorbed by 

 the mercury producing hyponitrite of mercury. 



The effect of heat on the solution of mercury formed in the cold was 

 singular. To simplify the explanation, we shall suppose that exactly fifty 

 grains had been used, which, according to Dr Thomson, should take up two 

 grains of oxygen to form the black oxide and four grains to form the red 

 oxide. Now a boiling heat being employed, nitric oxide was evolved and 

 collected, equivalent to two grains of oxygen. " This would have led me 

 to suppose I had obtained the black oxide in solution ; it was, however, en- 

 tirely the red, as it gave no precipitate by common salt and exhibited the 

 red oxide by lime water; but it required as much oxymuriate of lime as 

 contained two of oxygen to saturate the nitrous gas in the solution before 

 any oxymuriatic acid was liberated." It surely is more probable that the 

 ** oxymuriate of lime" acted on hyponitrous acid than on nitrous gas, since 

 Mr Dalton says he employed a boiling heat, and that only one-tenth excess 

 of acid remained in solution (p. 22.) The nitrate containing the red oxide 

 of mercury consists of 12.5 metal + 1 oxygen + 6.75 of acid = 20.25. 

 Now we conceive that out of the 50 of mercury, twenty-five produced 



• Annals of Philosophy, x. p. 43. 

 VOL. VIII. NO. II. APRIL 1828. Z 



