on the Atomic Theory. 129 



Prout's theory, whose truth he was labouring (most unskilfully, 

 it must be owned) to demonstrate, requires the experimental 

 specific gravity of moist hydrogen to be to that of moist air, as 

 0.07951 to 1.00000, a proportion very wide indeed of Dr. 

 Thomson's result. For, if hydrogen gas, standing over water, be 

 not to air standing over water, both at 60°, as 0.07951 to 1.0000, 

 then dry hydrogen gas will not be to dry air as 0.0694 to 1.0000. 



We are really ashamed of the necessity for such multiform details , 

 but the Doctor so unblushingly foists on the public his old battered 

 brass as genuine current coin, that we were here forced to call the 

 tilting hammer to our aid. 



*' The key- stone of the building" being removed by his own 

 hands, we shall have little further to do with the rest of his pile, 

 than to keep out of the way of the rubbish. But the real atomic 

 theory will not be injured by his debris. Has Dr. Thomson yet to 

 learn that he is not the architect of that edifice, but a very com- 

 mon labourer in the quarry ? and that its symmetry and solidity 

 are equally independent of his puny efforts ? 



The fundamental proposition, that oxygen and hydrogen are to 

 each other by weight, in the composition of water, as 8 to 1 ; and 

 that hence the other chemical bodies may be found, in their atomic 

 numbers, multiples of that for hydrogen, had been demonstrated 

 by Berzelius and Dulong, two of the most accurate experimenters 

 of the age. By transmitting dry hydrogen gas over black 

 oxide of copper, ignited in a tube, and collecting the water pro- 

 duced ; they found, on comparing its weight with the loss of 

 weight sustained by the oxide, that the ratio of the hydrogen to 

 the oxygen in water was 1 to 8.009 ; and since water consists of 

 two volumes of hydrogen + one of oxygen, the relation of their 

 densities is, as nearly as can be, -j\ ; whence calling the specific 

 gravity of oxygen 1.1111, that of hydrogen becomes 0.0G94. 



There is a note to the 72d page of the Attempt, which might 

 puzzle posterity. He states that the weight of his famous flask, 

 filled with the dilute sulphuric acid and zinc, was about 3000 

 grains. Yet, a few pages before, he tells us that " the capacity 

 of the flask was about IS cubic inches, " and that it " was nearly 

 filled with a mixture of sulphuric acid and distilled water, in the 

 proportion of about four parts of the latter to one of the former." 

 Now " about 18 cubic inches" of such acid, must weigh fully 

 5000 grains, and the glass flask itself, of this size, would pro- 

 bably weigh about 2000 more. Hence, with the zinc, its total 

 weight must have b»en at least twice 3000 grains. Or again, if 

 we take his weight, 3000 gr. versus his bulk of 1 8 inches, then 

 the contents (making an allowance of only 1000 gr. for his 

 glass) could not have exceeded 7 cubic inches. Is the experiment 

 of the flask altogether a fable, as these palpable contradictions 

 about its weight and capacity seem to indicate ? 



Vol. XX. K 



