182 Dr. Hare on a new Theory of Galvanism, [Sevt. 



lathe. The wood in the interstice was then charred by exposing 

 the whole covered by sand in a crucible to a red heat. The 

 charcoal, notwithstanding the shrinkage consequent to the fire, 

 was brought into complete contact with the inclosing metallic 

 surfaces by pressing the interior cylinder further into the exte- 

 rior one. 



Thus prepared, the exterior cylinder being made to touch one 

 of the galvanic surfaces, and a wire brought from the other 

 galvanic surface into contact with the outside cylinder, was not 

 affected in the least, though the slightest touch of the interior 

 one caused ignition. The contact of the charcoal with the con- 

 taining metals probably took place throughout a surface of four 

 square inches, and the wire was not much more than the hun- 

 dredth part of an inch thick ; so that unless it were to conduct 

 electricity about 40,000 times better than the charcoal, it ought 

 to have been heated, if the calorific influence of this apparatus 

 result from electrical excitement. 



I am led finally to suppose that the contact of dissimilar metals, 

 when subjected to the action of solvents, causes a movement in 

 caloric as well as in the electric fluid, and that the phenomena of 

 galvanism, the unlimited evolution of heat by friction, the extri- 

 cation of gaseous matter without the production of cold, might 

 all be explained by supposing a combination between the fluids 

 of heat and electricity. We find scarcely any two kinds of 

 ponderable matter which do not exercise more or less affinity 

 towards each other. Moreover, imponderable particles are 

 supposed highly attractive of ponderable ones. Why then should 

 we not infer the existence of similar affinities between imponder- 

 able particles reciprocally ? That a peculiar combination between 

 heat and light exists in the solar beams is evident from their not 

 imparting warmth to a lens through which they may pass, as do 

 those of our culinary fires. 



Under this view of the case, the action of the poles in galvanic 

 decomposition is one of complex affinity. The particles of com- 

 pounds are attracted to the different wires agreeably to their 

 susceptibilities to the positive and negative attraction, and the 

 caloric leaving the electric fluid with which it had been com- 

 bined unites with them at the moment that their electric state is 

 neutralized. 



As an exciting fluid, I have usually employed a solution of 

 one part sulphuric acid and two parts muriate of soda, with 70 

 of water ; but, to my surprize, I have produced nearly a white 

 heat by an alkaline solution barely sensible to the taste. 



For the display of the heat effects, the addition of manganese, 

 red lead, or the nitrates, is advantageous. 



The rationale is obvious. The oxygen of these substances 

 prevents the liberation of the gaseous hydrogen, which would 

 ^carry oft' the caloric ; adding to diluted muriatic acid, while act- 





