PREFACE. 



THE great work of M. Berthelot has for some years been a 

 mine from which copious stores of valuable matter have been 

 obtained and translated into various languages. 



So far, however, no English translation or adaptation of the 

 book, as a whole, has appeared. 



The idea of making such a translation, or, rather, condensation^ 

 of M. Berthelot's somewhat bulky volumes occurred some time 

 ago to Mr. Hake and myself. Circumstances, however, notably 

 the appointment of Mr. Hake to the Inspectorship of Explosives 

 in the Colony of Victoria, and a considerable pressure on my 

 own time, prevented our carrying out this project in the way 

 originally intended. But Mr. Macnab, then associated with, 

 and subsequently successor to, Mr. Hake in his London business, 

 has undertaken and carried out the larger portion of the very 

 laborious work involved, and thus it is really to his energy 

 and kindness that the work as it now appears is due. M. 

 Berthelot's reputation as a scientist is world-wide ; his atten- 

 tion was first especially drawn to explosives in the year 1870, 

 and his labours have been continued with little, if any, inter- 

 mission to the present time. 



The great key-note of the work now translated is the applica- 

 tion of thermo-chemistry to the study of explosives. Though 

 not the first in this field, yet M. Berthelot has, in the extent 

 and variety of his researches, eclipsed his colleagues, and it is 

 mainly due to him that thermo-chemistry occupies the position 

 which it now holds in this department of science. 



The book does not pretend to be a practical guide to 

 manufacture, but is, on the other hand, most valuable to the 





