Mr. W. R. Grove on the Electricihj of the Blowpipe Flame. 47 



and the other a group of twenty-seven, viz. 



1, u, a^ y, y^ ya, ay, yu^, a^y, y^«, *y^ y^«^ «y, 



uya., ay^a, m^yoi, a^y'^a, oiya.^, arfa^, a-ya^ «V«^ . 



y«y^, yaVj /^V^' y^«^yj 



y'-a.ya.^, ya.y-a-, 

 where 



«3 = 1, y3 = i^ (y«)3 = l, (y^«)3 = l, (7«T = 1, (yVf = 1. 

 It is hardly necessary to remark, that each of these groups is 

 in reahty perfectly symmetric, the omitted terms being, hi virtue 

 of the equations defining the nature of the symbols, identical 

 with some of the terms of the group : thus, in the group of 18, 

 the equations ofi=\, I3^ = l, y^ = l, («)Sy)^ = l give u^y=y/3a, 

 and similarly for all the other omitted terms. It is easy to see 

 that in the group of 18 the index of each term is 2 or else 3, 

 while in the group of 27 the index of each term is 3. 



2 Stone Buildings, Nov. 2, 1853. 



Vin. On the Electricity of the Blowpipe Flame. 

 By W. R. Grove, F.R.S. ^r.* 



VOLTA and Erman made known the first indications of the 

 production of electricity by flame. Pouillet and Becquerel 

 have experimented and reasoned on the statical effects of such 

 electricity, while Andrews, and more recently Hankel and Bufi^, 

 have published very interesting results on the efi'ects of flame as 

 to conduction and production of voltaic electricity. 



The experiments of which I am about to give a notice were 

 for the greater part made before I had read the papers of the 

 two last authors ; and while they in many respects difi'er from 

 theirs, they give a means of producing a voltaic current from 

 flame far more distinct and powerful than any which I have tried 

 or read of. 



The flame I have worked with is that of naphtha or spirits of 

 wine, urged by an ordinary glass-worker's blowpipe ; and with a 

 galvanometer, the needles of which are barely deflected to 2° by 

 any current which I can procure by the flame of a common 

 spirit-lamp, I can by the blowpipe flame procure deflections of 

 20° or even 30°, and with great certainty and uniformity of 

 direction. 



I am not aware that the blowpipe flame has ever been used 

 for the production of electricity, though I see by M. E. Bec- 



♦ Communicated by the Author. 



