198 ANNUAL OF SCIENTIFIC DISCOVERY. 



what I have stated ; in passing the hand into any metal in fusion, it 

 becomes isolated ; the humidity which covers it passes into the sphe- 

 roidal state, reflects the radiating caloric, and does not become heated 

 enough to boil. This is all with reference to the spheroidal theory. 

 I have often repeated the experiments with lead, bronze, &c." 



In a later number of the Comptes Rendus, M. Boutigny details 

 some further experiments. 



" I moistened with water my forefinger, which I plunged into a 

 bath of lead, when I experienced the same feeling of warmth which 

 water gives in a spheroidal state. When I used alcohol for mois- 

 tening my finger, the effect was the same ; but when ether was used 

 there was no sensation of heat, but, on the contrary, an agreeable feel- 

 ing of coolness. I have repeated this experiment several times, and 

 do not hesitate to declare that it is perfectly harmless, and that the 

 most delicate female could do the same, not only without the least 

 danger, but without the slightest inconvenience. But the finger 

 should be plunged in as soon as it is moistened, and when the metal 

 is perfectly liquid. It should be mentioned, that the portions of the 

 hand which are not immerged in the fused metal, but are exposed to 

 the action of the heat radiated from its surface, experience a painful 

 sensation of heat." M. Boutigny then details some experiments by 

 which he thinks that he proves that " bodies in a spheroidal state are 

 surrounded by an atmosphere whose molecules are connected in such 

 a way that it may be compared to a solid transparent envelop, of an 

 infinitely small thickness and possessing very great elasticity." 



THE HEAT OF COMBINATIONS. 



EvERy molecular change in the condition of matter is almost inva- 

 riably connected with the evolution or absorption of heat, and the 

 quantity of heat thus set free or absorbed bears always a definite re- 

 lation to the amount of the mechanical or chemical action. To as- 

 certain this relation has been the object of my investigations, and 

 the following are a few of my principal results. 1. The solution of 

 a salt in water is always accompanied by an absorption of heat. 

 2. If equal weights of the same salt be dissolved in succession in the 

 same liquid, the heat absorbed will be less on each new addition of 

 salt. 3. The heat absorbed by the solution of a salt in water hold- 

 ing other salts dissolved is generally less than that absorbed by its 

 solution in water. 4. The heat absorbed by the solution of a salt in 

 the dilute mineral acids is generally greater than that absorbed by its 

 solution in water. In reference to the combination of acids and 

 bases, the heat developed during the union is determined by the 

 base, and not by the acid. An equivalent of the same base" com- 

 bined with different acids produces nearly the same quantity of heat. 

 When a neutral salt is converted into an acid salt by combining with 

 one or more equivalents of acids, no disengagement of heat occurs. 

 When a double salt is formed by the union of two neutral salts, the 

 same is the case, but when a neutral salt is converted into a basic 



