330 Dr, Hare's neiv Gnhanic Apparatus, Theory, ^c. [May, 



in voltaic apparatus of extensive series had never been attained. 

 The plates are generally arranged in distinct troughs, rarely 

 containing more than 20 pairs. Those of the great apparatus of 

 the Royal Institution, employed by Sir H. Davy, had only 10 

 pairs in each. There were 100 such to be successively placed 

 in the acid, and the whole connected ere the poles could act. 

 Consequently the effect which arises immediately after immer- 

 sion would be lost in the troughs tirst arranged, before it could 

 be produced in the last ; and no effort appears to have been 

 made to take advantage of this transient accumulation of power, 

 either in using that magnificent combination, or in any other 

 of which I have read. In order to observe the consequence of 

 simultaneous immersion with a series sufficiently numerous to 

 test the correctness of my expectations, a galvanic apparatus of 

 80 concentric coils of copper and zinc was so suspended by a 

 beam and levers as that they might be made to descend into, or 

 rise out of, the acid in an instant. The zinc sheets were about 

 nine inches by six, the copper fourteen by six; more of this metal 

 being necessary, as in every coil it was made to commence within 

 the zinc, and completely to surround it without. The sheets 

 were coiled so as not to leave between them an interstice wider 

 than a quarter of an inch. Each coil is in diameter about two 

 inches and a half, so that all may descend freely into 80 glass 

 jars two inches and three-quarters diameter inside, and eight 

 inches high, duly stationed to receive them.* 



My apparatus being thus arranged, two small lead pipes were 

 severally soldered to each pole, and a piece of charcoal about a 

 quarter of an inch thick, and an inch and a half long, tapering a 

 little at each extremity, had these severally inserted into the 

 hollow ends of the pipes. The jars being furnished with diluted 

 acid, and the coils suddenly lowered into them, no vestige of 

 the charcoal could be seen. It was ignited so intensely, that 

 those portions of the pipes by which it had been embraced were 

 destroyed. In order to avoid a useless and tiresome repetition, 

 •I will here state that the coils were only kept in the acid while 

 the action at the poles was at a maximum in the experiment just 

 mentioned; and in others, which I am about to describe, unless 

 where the decomposition produced by water is spoken of, or the 

 sensation excited in the hands. I designate the apparatus with 

 which I performed them as the galvanic defiagrator, on account 

 of its superior power, in proportion to its size, in causing defla- 

 gration ; and as, in the form last adopted, it differs from the 

 voltaic pile in the omission of one of the elements heretofore 

 deemed necessary to its construction. 



Desirous of seeing the effect of the simultaneous immersion of 

 my series upon water, 'the pipes soldered to the poles were 

 introduced into a vessel containing that fluid. No extraordinaary 



•.See Plate VII. 



