THE 
AMERICAN JOURNAL OF SCIENCE. 
[THIRD SERIES.] 
Abr. XXXII Notice of Berthelot's Thermo-Chemistry ; by 
J. P. Cooks, JR. 
_ THE new work of M. Berthelot, entitled ‘“‘ Essai de Mécan- 
\que Chimique fondée sur la Thermo-chemie,” presents for the 
first time in a systematic form the results accumulated during 
the past ten years from one of the most fruitful fields of investi- 
Sation ever opened to the chemist. The book supplies a most 
™portant want, for the details of the work—published in 
humerous separate papers rapidly following each other in 
the chemical journals—have been almost unintelligible, ex- 
arte Berthelot, of Paris, and Thomsen, of Copenhagen. 
uided by different theoretical views, these skillful experiment: 
ets have gone over very nearly the same ground, and their 
united testimony, concurrent as it is in most cases, gives a 
Certainty to the results obtained which is as fortunate as it is 
"nusual when the field explored is so extensive as the one we are 
Considering. These two men alone could write authoritatively 
On the subject, and it is, perhaps, fortunate that the first pre- 
Sentation should come from M. Berthelot, who has the usual 
skill of his nation in exposition and generalization. 
‘n his introduction, Berthelot enunciates the fundamental 
Principles of thermo-chemistry under the three following heads : 
- Jour. Sor.—Tarrp — Vor, XIX, No. 112,—Aprit, 1880, 
