( 34C ) 



An Account of Experiments with Thermo- and Hydro- Electrical 

 Currents, rvith an examination of the Metals exposed to 

 Thermo- Electric action. By Mr R. Adie of LiverpooL 

 Communicated by the Author. 



The experiments detailed in the following communication, had their 

 origin in a desire I felt to test a hypothesis, which regarded heat as a 

 binary compound, composed of latent heat and electricity. The 

 study of thermo-electricity had already induced M. Becquerel to hold a 

 view not very dissimilar, viz. that under some circumstances heat was 

 resolved into the two electricities ; and again, that the two electricities 

 could combine, and produce heat. From the same source I hoped to 

 derive proof or disproof of the theory that latent heat and electricity 

 could unite, but the experiments had not proceeded far, before I began 

 to despair of obtaining evidence on this head ; nevertheless, theresultsgiven 

 by the first attempts appeared to me sufficient to encourage further ex- 

 aminations, when they were conducted without reference to the hypo- 

 thesis in question. I then resolved to follow only the experiments, and 

 it is with the details of that part of them which appears to me to be 

 worthy of the attention of your readers, that this paper is now sub- 

 mitted. 



I was desirous to obtain a thermo-electric battery, which would pro- 

 duce as powerful a current as possible, by the action of sun and sky, 

 without the aid of differences of temperature sustained by artificial 

 means. M. Melloni's small needles of antimony and bismuth are known 

 to form a thermo-electrical battery of great sensibility, but for a perma- 

 nent current sustained solely by the temperature due to diflPerent radia- 

 tions through the atmosphere of the two extremities of the bars, I found 

 longer pieces of antimony and bismuth far more effective. On varying 

 the length of these pieces of metal from 1 to 16 inches, I found 8 inches 

 to develope the full power of a single pair. 



When the number of bars of antimony and bismuth are gradually inr 

 creased, the quantity of electricity indicated by the galvanometer" fol- 

 lows in the same direction, but from each successive addition of a pair 

 of bars, the quantity of electricity derived from that addition decreases, 

 as the number of bars, or length of the electrical current, increases ; so 

 that, when 2 sets of 30 pairs of M. Melloni's bars are combined together, 

 to form one battery of 60 pairs of antiraonj'- and bismuth needles, there 

 is a far greater gain in quantity of electricity by this addition of 30 to 30, 

 than we gain from the next similar addition of 30 to the circuit of 60 

 pairs. 



Beyond 90 pairs of antimony-bismuth bars of the size used by M. 

 Melloni, combined in a single battery, I have not been able to gain any 

 augmentation to the electrical current. If 8-inch bars be employed, and 



