Correspondence of J. Nickles. 407 
~ Art. XLI.—Correspondence of M. Jerome Nicklés, dated, Paris, 
Dec. 30, 1854, 
- Acapemy oF Scientes.—On the relations which exist between the 
chemical composition of bodies and their physical properties—The 
densities of their vapors, studied the great questions of isomerism, poly- 
Merism and polymorphism, while at the same time he was erfecting 
the methods of investigation, and was also engaged with M. Liebig in 
bringing organic chemistry to the condition of a science. om 
Besid e communication which he made in 1851 to the British 
Association, an abstract of which has appeared in the American Journal 
of Science, M. Dumas has published nothing for some years. However, 
he has often spoken on the subject, in his course of lectures on Organic 
Chemistry at the Ecole de Médecine, and also since 1852, in his General 
Course on Chemistry, at the Faculty of Sciences (Sorbonne): and when 
1. The isomorphism of the crystallized ethers of the same kind. 
2. The isomnce phil of salts of the same kind and of the same ho- 
mologous alkaloi wr . 
8. The (dotnet of the anhydrous salts of the same base and of 
homologous acids. ess 
4. The hemimorphism of these same salts differently hydrated. 
e phiques, par M. Nic des Tray. Chem. 
* Recherches erystallographiques, par M. Nicklés, Comptes Rend. 
~ de Laurent et Gerhardt, 1849. | 
