338 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 



strip of platinum immersed in strong nitric acid, and sepa- 

 rated by a porous cylinder, or cell, from well amalgamated 

 zinc cylinders immersed in dilute sulphuric acid ; the zinc 

 of the one cell being attached to the platina of the succeed- 

 ing cell. 



Description of Grove's Galvanic Battery. (Fig. 400, next 

 page.) This consists of slips of platina, placed in porous por- 

 celain cups, the cups surrounded with thick zinc cylinders, 

 placed in a glass, or glazed porcelain vessels. The platina in 

 each cup is attached to the zinc cylinder in the next, except 

 at the extremities or poles, the platina being the one pole, 

 and the zinc the other ; to each of which, supports are at- 

 tached with brass cups, having binding screws, to receive 

 conducting wires for experimenting with. 



The power of this instrument is about twenty times as 

 great as the common zinc and copper arrangement ; its price 

 not one quarter in proportion to its effect ; and a powerful in- 

 ducing the most brilliant light with the charcoal points, insupporta- 

 ble to the naked eye, burning the metals and decomposing water 

 with rapidity. A silver medal was aivarded for the battery. Also 

 constructed one of about one hundred series for Prof. Ellet, of the 

 University of S. C., who sent the following letter: 



SOUTH CAROLINA COLLEGE, June 10th, 1845. 



DEAK SIR, In reply to your request for information as to the 

 working of the " Grove's Galvanic Battery " you constructed for me 

 last summer, it. gives me great pleasure to assure you, that it has 

 more than equalled the high expectations I entertained. 



With the whole arrangement connected in series, the effect in the 

 deflagration of metals, charcoal, &c., was surprisingly brilliant, as 

 you may judge from the fact, that the light was so intense as to pro- 

 duce an inflammation of the eyes, which confined me to my room 

 for several days, and required active medical treatment. 



I would suggest to you as the result of much experience with the 

 instrument, that so extended an arrangement as mine is neither 

 necessary nor desirable for the greater number of purposes for which 

 a galvanic battery is required. A series of from fifteen to twenty 

 pairs of plates is as much as can be used to advantage for chemical 

 decomposition, which it effects far more vigorously than any of the 

 old arrangements of much greater extent : while it is at the same 

 time quite sufficient for producing brilliant deflagrations. One or 

 two pairs are enough for nearly all the experiments in Electro-Mag- 

 netism, including that of working Prof. Morse's telegraph. 



Apart from the neatness and compactness which form so important 

 a feature in Grove's instrument, I have no hesitation in saying, that 

 I believe the experimenter will find it the most economical form of 

 the galvanic battery he can employ. 



1 am, dear Sir, very respectfully yours, 



To BENJ. PIKE, JR. WILLIAM H. E.LLET. 



