436 On a new heating Effect of a Constant Battery. 



not pretend to decide. Of the justness of Dugald Stewart's 

 views on the subject he is himself fully convinced, but he has 

 not time at present to enter into a question, which indeed 

 appears to have been fully discussed already. 



Cambridge, Sept. 18, 1838.' Z. Y. 



LXI. On a remarkable Difference in the Heat attained hy the 

 Electrodes of a yo^werfal Constant Battery . By J. P. Gassiot, 

 Esq. : in a Letter to Mr. Brayley. 



My dear Sir, 

 n|^HE following result, obtained with an extensive series of 

 ^ the voltaic battery made on the principle of that of Prof. 

 Daniell, may, perhaps, not be uninteresting to you. The 

 battery consists of 160 half-pint earthenware jars, the zinc 

 elements being placed inside, the size permitting the use of 

 brown paper in lieu of membrane, the exciting liquids being 

 saturated solutions of sulphate of copper and common salt. 



The effects were of the most brilliant description, and some 

 curious results were obtained, particularly as to its heating 

 power. The following is, I believe, entirely new, and as it 

 in some measure militates against the theory of a double fluid, 

 may, perhaps, be acceptable to the readers of the Philosophi- 

 cal Magazine. 



On placing the ends of the connecting wires about two 

 inches from their extremities, across each other, and about 

 one-eighth of an inch apart, the usual appearance of flame 

 took place : on gradually withdrawing the wires at this con- 

 nexion the flame could be increased to one-fourth of an inch 

 in length. In about half a minute the end of the positive wire 

 became red-hot ; it very shortly increased to a white heat, 

 until at last it could not bear its own weight, but turned over 

 as indicated in the figure. 

 Considering that the effect 

 might possibly be due to 

 some peculiar property in 

 the wires, they were re- 

 versed ; but the effect was 

 the same, the positive wires 

 being invariably heated at 

 least two inches beyond the 

 contact, while the negative ^*" ^^' 



remained cool. The experiment was repeated on a future 

 evening with the same results. 



A variety of experiments were made with this battery, an 

 account of which has since been presented to the Electrical 



