Biographical Memoir of M. Duhamel. 5 



M. Trudaine^s choice, as directed by M. Peyronnet, fell on 

 M. Jars and on M. Duhamel, whose history we are relating. 



As a preparation for their journey, they were sent to inspect 

 the most important mines which France then possessed. From 

 1754 to 1756, they visited those of the Ardennes, of the Vosges, 

 and of the Pyrenees ; and, in 1757, they set out for Germany. 



The diligence with which they applied to their researches, 

 may be judged of by the collection published under the title 

 Voyages Metallurgiques, which bears the name of M. Jars, but 

 which is in a great measure the result of their united labours. 

 All the memoirs regarding the forges of Austria, Styria, and 

 Carinthia, and those of Bohemia and Saxony, are the work of 

 the two young authors, and several of these memoirs were com- 

 posed by M. Duhamel alone. 



It would be unjust to estimate this work according to the 

 present state of our knowledge. In the period of more than 60 

 years which has elapsed since it was published, the theory of all 

 the sciences which treat of minerals has undergone two or three 

 revolutions; and it must be remembered, that, at the time we 

 allude to, the masters whom our young inquirers could consult 

 were not theoretical men. The ideas which the directors and 

 proprietors of mines then possessed, were scarcely more elevated 

 than those of the workmen whom they employed. Every thing 

 seemed mysterious in the purely empirical results on which their 

 procedures were founded. The birth and maturity of metals 

 were believed in ; nature, it was said, required to be aided in 

 bringing them to perfection. Mercury, sulphur, and salt, vari- 

 ously modified, formed their elements. In a word, metallurgy 

 spoke almost entirely the language of alchymy. 



Geology was still farther from having attained a scientific 

 form. As yet, Lehman had scarcely distinguished with pre- 

 cision the secondary from the primitive mountains. The nu- 

 merous circumstances relating to the superposition of minerals 

 were not even imagined. Desaussure had not travelled, Deluc 

 had not written, nor had Werner yet, by the power of his supe- 

 rior genius, in some measure reduced to order the mineral 

 world. 



It is a reflection wliich we are frequently obliged to make, 

 when we have to retrace the history of our fellow-members 



