Biographical Memoir of M. Duhamel 11 



and time had recently added to the art. His devotion to his 

 duties, and his love to his pupils, supplied all ; from the begin- 

 ning he shewed himself worthy of his situation, and during the 

 thirty years he filled it, the affection and gratitude of those 

 whom he taught continually rewarded his labours. The gra- 

 titude of many others also was due to him, could he have re- 

 claimed it from all those whom he has enriched. 



In fact, if it be desired to know what effect a well arranged 

 institution, however inconsiderable it may be, what a public pro- 

 fessorship, for example, may produce in a great kingdom, let it 

 be considered what our mines then were, and what they have 

 since become. Our workings of iron and coal are quadrupled; 

 the iron mines which have been opened near the Loire, in the 

 coal district, and in the midst of fuel, will produce metal at the 

 same price as in England. Antimony and manganese, which 

 we formerly imported, we now export largely. Chrome, which 

 was discovered by one of our chemists, is also now the very 

 useful production of one of our mines. Already very fine tin has 

 been extracted from the mines of the coast of Bretagne. Alum 

 and vitriol, formerly unknown in France, are collected there in 

 abundance. An immense deposit of rock-salt has lately been 

 discovered in Lorraine, and there is every reason to believe that 

 these operations will not stop there. It is not undoubtedly to a 

 single individual, nor to the erection of a single chair, that all 

 this good can be attributed ; but it is not the less true, that this 

 man and this chair gave the first impulse. 



It was for his pupils that M. Duhamel composed his princi- 

 pal work, of which a volume appeared in 1787, under the title 

 of Geometrie sotiterraine. 



It is well known that the metals, and especially the more pre- 

 cious metals, have not been distributed by nature in homogeneous 

 and extended masses. Dispersed in small parcels among rocks, 

 it is only by great labour that man has been able to become pos- 

 sessed of them. Nor have they anywhere been scattered at ran- 

 dom. Their position, like all the other relations of natural objects 

 to each other, is subjected to laws. It might be said that the old- 

 est mountains have been broken or split to afford them asylums. 

 Those immense fissures which traverse rocks in all directions. 



