82 GALVANISM. 



inches, of course I had the power of 4400 inches. The 

 oxidating fluid I made use of was good nitrous acid, with 

 aboui sixteen times its bulk of water. On passing the gal- 

 vanic fluid through about one ounce of water, by means of 

 platina wires, I was much surprised at the quantity of calo- 

 Muchheatwasric which was liberated as the water became decomposed; 

 ^h°^"ater^" *^^ temperature of the tube which contained the water 

 seemed to be about (as near as I could judge by the touchy 

 180<» of Fahrenheit; but as I wished to ascertain the tem- 

 perature more correctly, I immediately applied the bulb of 

 a thermometer, though it was very unfavourable to ascer- 

 tain the temperature, as the bulb of a small thermometer 

 could touch a tube of one inch diameter at a very small sur- 

 The thermo- face, but the mercury soon rose 10°. Not having any person 

 meter shewed with me, and endeavouring to regulate the wire which com- 

 ^° ^^' municated from the battei-y to the tube of water with one 



hand, while the other was engaged in holding the thermo- 

 meter against the tube. I accidentally brought the positive 

 and negative platina wires in contact, Avhich exploded the 

 gases, and forced the tube violently up a considerable height, 

 which falling on the table, broke, and prevented me accom- 

 plishing my wish relative to the temperature of the water 

 under decomposition. 

 Another expc- A short time after, in my lecture on the subject, I noticed 

 nmcnt. ^yjg circumstance ; and one or two of my audience, after the 



lecture, on applying their hands to the tube while the water 

 was decomposing, hastily withdrew them on account of the 

 heat. 



I cannot, Sir, account for the liberated caloric by any 

 heat produced? other means than supposing that the galvanic fluid furnished 

 more caloric than was necessary to convert the water into 

 gases. If, Sir, this meet with an insertion, I shall commu- 

 nicate more on the above subject the first opportunity ; 

 until when permit me to remain, 



Your's, most respectfully, 

 Dorset Street, JOHN TATUM, Jun. 



Jan, bill, 180?. 



