12 Mr. Seaward's Description of a Hydro-pneumatic Pump 



This is what I had to state, from the crystallo-electric theory, 

 respecting the new mode of producing fire, discovered by Prof. 

 Dcebereiner. I do not consider this explanation as entirely sa- 

 tisfactory; but I think it not unbecoming the present state of 

 natural philosophy, if at least I have succeeded in thereby con- 

 necting it with the other phaenomena of nature : if any thing is 

 to be advanced on this subject from the electro-chemical theory, 

 it is only the crystallo-electricity that can throw any light upon 

 it. As hydroguretted carbon stands near to the zinc in the 

 positive electric series, while oxidated carbon is still more ne- 

 gatively electric than silver or platinum, it was certainly in that 

 respect a very ingenious supposition of M. Dcebereiner, when 

 he compared the activity of the hydrogen with regard to the 

 platinum * to that of zinc ; and that he so far thought of the 

 excitement of electricity by contact. Soon afterwards, how- 

 ever, he renounced this theory, in his public reading before 

 the Assembly of Naturalists at this place (Halle), which at pre- 

 sent would be even less tenable, as even carbonic oxide gas is 

 made to unite with oxygen by the platinum sponge, as we 

 have just seen from the dissertation of the French chemists f. 

 With regard to the electro-chemical explanation, it appears 

 that the above view of crystallo-electricity alone remains. 



For the illustration of the preceding Essay, I will add an en- 

 cyclopedic review of my crystallo-electric theory, the considera- 

 tion of which gains in interest on account of Dcebereiner's 

 important experiments. This will be nearly as published at 

 a former period in the Universal Encyclopedia, conducted by 

 Ersch and Gruber, under the article Attraction^. 



II. Description of a Hydro - pneumatic Pump for compressing 

 Gases or other elastic Fluids. By Mr. Samuel Seaward. 



To the Editors of the Philosophical Magazine and Journal. 

 Gentlemen, 

 r I "'HE accompanying description of an hydro-pneumatic 

 -■■ pump, which I have invented for the pressure of com- 

 pressing gas, would have been forwarded to you a long 

 time back, but I was desirous of seeing the machine tried be- 

 fore I offered it to the attention of the public. Being now 

 fully satisfied on this point, as it performs all that was ex- 



* See Phil. Mag. vol. lxii. p. 291. f Ibid. p. 285. 



% We purpose to give a translation of this account of the crystallo- 

 electric theory in a future Number.— Edit. 



pected 



