Miscellanies. 373 



ordinarily produced by about one third of the same number of gal- 

 vanic combinations of equal surface, excited by acid — considerable 

 lengths of thin wire were fused, &;c. A common electrical battery 

 of great size, containing seventy feet of coated surface, was charged 

 in a single instant, if connected with the wires proceeding from the 

 extremities of the galvanic series; and when successive discharges 

 were, under these circumstances, taken from the electrical battery, 

 the eiFects were most intense. After receiving three or four such 

 discharges on the point of my pen knife I found, on examining it 

 with a glass that its extremity had been completely fused. 1 need 

 not dwell on the extreme importance of having constructed an appa- 

 ratus capable of producing such powerful effects, when excited by 

 water only ; the excitation by acid is violent at first, but goes on 

 rapidly decreasing, and at the end of three hours becomes almost 

 null. If it were attempted to sustain an uniform action, by the con- 

 tinual affusion of fresh acid, the zinc plates would be entirely corro- 

 ded in a very few days; indeed, the constant attendance necessary, 

 and the enormous expense, would render such an attempt practically 

 impossible. But in Mr. Crosse's apparatus, though excited by wa- 

 ter only, we have a strength equal to very large ordinary troughs, 

 say three hundred plates, and that strength is uniform and permanent, 

 and requires no further attendance than replenishing the water, (from 

 the loss sustained by evaporation,) once in six weeks ; in this mode 

 also, the corrosion is so slow, that the same apparatus might proba- 

 bly last for twenty years ; much of it has already been in constant 

 action much more than a year, and does not seem in the least im- 

 paired. The importance of imitating nature, by keeping in constant 

 and uniform, activity such powerful galvanic currents, must be obvi- 

 ous. Besides the series I have described, Mr. Crosse had begun 

 to construct one of much larger dimensions; each cylinder contain- 

 ing a square foot in surface. Should he proceed with equal vigor 

 we may expect some day to hear of two thousand of such cylinders ; 

 the effects must then be almost terrific. Could we, inquisitor-like, 

 put nature to the question, by so efficient an instrument, she could 

 hardly resist any interrogatories we might please to put to her, and 

 all the mysteries which at present perplex us in chemistry might be 

 expected to stand revealed. I should regard the completion of such 

 an apparatus as quite a national object; and I feel convinced, that it 

 is by proceeding in this line that we may best hope to see the force 

 of electricity practically applied as a moving power, and the energy 



