102 Hare on the Galvanic Deflagrator. 
the copper and zinc surfaces of the deflagrator pairs, repre- 
sented bv fig. 2, and in the mode in which the acid is 
thrown off, or on, the whole series, which does not differ, 
materially, from that described in the instance of 
On contrasting the series of 50, (fig. 4.) with “Cruick- 
shank’s plates in the box, (fig. 5. ) the deflagrating power 
of the latter was found comparatively feeble ; ~ see even 
when compared with the Cruickshank trough, (fig. 6.) in 
igniting metals, or carbon, the 50 pairs (fig. 4.) were found 
greatly superior." The shock from the Cruickshank trough 
was more severe. You must recollect, that in former ex- 
pees I found that galvanic plates, with their edges ex- 
osed es y are in the porcelain troughs, used by Sir 
Davy, were almost inefficient, when used with- 
out sentient, as are the pairs of the deflagrator. This de- 
monstrates, that an unaccountable difference is producible 
in galvanic apparatus, by changes of form or- position. 
Being accustomed to associate the idea of the zinc pole, 
ina Voltaic series, with the end terminated by zine. and the 
copper pole, with the end terminated by copper, I was sur- 
prised to find that, in decomposing water, the oxygen was 
attracted by the wire connected with the copper end of my 
deflagrator, while the hydrogen went to the wire connected 
with the zine end. Subsequently, however, it occurred to 
me, that, in the deflagrator the zinc pole is terminated by 
copper, the copper pole by zinc; and hence the apparent 
anomaly, that oxygen appears. to = attracted by copper, 
and bydrogen to be attracted by zi 
The projection from the tintin gone between the 
poles, takes place at the negative pole of the pile, and not 
at the positive pole, as you have alleged; and thus your ob- 
servation, that the current of igneous matter is from the 
opine to the zinc, may be reconciled with the Franklinian 
theory 
The observations, which are the subject of this commu- 
nication, combined with those which you have made, of the 
a recty of the deflagrator, and Voltaic series in the usual 
rm, to act, when in combination with each other; must 
justify us, in considering the former, as a galvanic instru- 
ment, eine great and peculiar powers. 
Since the above was written, I have tried my series of 
300 pairs: The projectile power, and the shock, were 
