NEW LAW IN THERMOCHEMISTRY 37 



culties of the problem are so far but partly overcome. A path 

 has been opened, but it is not yet perfectly smooth. 



CONCLUSIONS. 



The evidence presented in this memoir tends to establish a 

 number of conclusions, which may be summarized as follows : 



I. The absolute heat of formation of any chemical compound 

 is a function of the number of atomic unions in the molecule. 



II. In the group of substances represented by the aliphatic 

 hydrocarbons, their halides, sulphides, ethers and amines, the 

 absolute heat of formation is directly proportional to the number 

 of unions in the molecule. 



III. The absolute heat of formation of any organic compound 

 is a multiple, by a whole number, of a single constant. This 

 constant, the henotherm, is identical with the neutralization con- 

 stant, and has a value somewhere between 13700 and 13800 

 calories. 



IV. The thermal value of a union between two atoms is inde- 

 pendent of their masses. This is illustrated by the thermal 

 equality of corresponding chlorides, bromides and iodides, and 

 with this observation Faraday's law seems to be correlated. 



Washington, November 17, 1902. 



