Dr. Woods on the Heat of Chemical Combination, 67 



Table showing the quantity of heat produced in 1000 grs. of water 

 by the oxidation of an equivalent of each substance, 0=1. 



Name of substance Units of 

 oxidized. heat. 



Ratio. 



Name of Experimenter. 



Latent heat of ice . 

 Latent heat of steam 



Iodine 



Chlorine 



Nitrogen 



Silver 



Selenium ... 



Mercury 



Palladium ... 

 Molybdenum 



Carbon 



Arsenic 



Antimony ... 



Copper 



Cobalt 



Bismuth 



Nickel 



Lead 



Hydrogen ... 



Tin 



Phosphorus 

 Cadmium . 



Iron 



Zinc ....... 



Manganese . 

 Barium .... 



Aluminium. 

 Sodium .... 



Potassium . 



•1603 

 1-287 



•8 

 -1-6 

 1-6 

 1-6 

 27 

 2-4 

 2-42 

 3-38 

 33 

 4-8 

 4-8 

 4-9 

 4-8 

 4-82 

 6-5 

 6-2 

 7-8 



80 



81 

 8-18 



7-95 



9-6 

 10-4 

 12-8 

 1616 

 17-5 

 17-3 



•1603 

 8 times -1603 



5 times ^1603 



I twice*-8"*J 



I 3 times -8 -j 

 i- 4 times '8 < 



10 times -8 



12 times -8 



13 times -8 

 16 times '8 

 20 times -8 



j 22 times -8 



Woods. 



Favre and Silbermann. 



Woods. 



Woods. 



Favre and Silbermann. 



Woods. 



Woods. 



Woods. 



Favre and Silbermann. 



Favre and Silbermann. 



Woods. 



Favre and Silbermann. 



Woods. 



Woods. 



Woods. 



Favre and Silbermann. 



Favre and Silbermann. 



Mean of Andrews and Favre 



and Silbermann. 

 Favre and Silbermann. 

 Woods. 

 Mean of Andrews and Favre 



and Silbermann. 

 Favre and Silbermann. 

 Woods. 

 Woods. 

 Woods. 



Favre and Silbermann. 

 Favre and Silbermann. 



Note. — I proved in a paper published in the Philosophical Maga- 

 zine for October 1851, that " the decomposition of a compound body 

 absorbs as much heat as the combination of the elements originally 

 produced." I believe I was the first to prove this as a general propo- 

 sition, and, by so doing, laid the foundation of almost all the thermo- 

 chemical researches since carried on ; for, as far as I am aware, no 

 process which took decomposition into account was used before my 

 paper was published. 



In a paper read to the British Association at Belfast, and pub- 

 lished in the Philosophical Magazine for November 1852, I proved 

 that the intensity of chemical affinity might be measured by the 

 quantity of heat produced by the combination. 



As regards the first of these papers, Mr. Joule published in the 

 Philosophical Magazine for June 1852, a memoir proving exactly 

 the same proposition, but giving me the merit of priority in a pre- 

 liminary remark. It is, however, singular that Favre and Silber- 

 mann bring forward in 1853 (Annates de Chimie et de Physique^ 



r2 



