1825.] of Claude-Louis Berthollet . 165 



iiis country seem to follow in the train of Berthollet's scientific 

 research, and to spring up and flourish at his command. 



-The visit to the Natron Lakes was thus productive of two 

 great advantages. It benefitted science by furnishing the solu- 

 tion of what had long been a very interesting but a very puzzhng 

 problem, and it furnished a new and useful process to the arts of 

 every commercial country having immediate access to the sea. 

 But besides these, it was attended by a third result, contrasted 

 with which the other two may be almost said to lose their com- 

 parative importance. This is a strong expression, but few philo- 

 sophers will not account it a just one when they are informed 

 that the new views which forced themselves on the rich and 

 original mind of Berthollet, as he studied the progress of the 

 phenomena of the Natron Lakes, in order to explain the manner 

 in which the two salts act upon and decompose each other, 

 opened up to him a train of ideas, which after being matured and 

 digested, formed the subject of the profoundest work that has 

 hitherto appeared on the nature of chemical affinity. The out- 

 lines of this work were already sketched, and indeed its leading 

 doctrines were nearly developed ere Berthollet left Egypt. He 

 read a memoir on the subject to the Institute of Egypt, which he 

 published immediately on his return to France ; and after many 

 interesting experiments, and much additional illustration and 

 development of his principles, the work itself appeared a few 

 years after under the title of Statique Chiraique. 



During the whole of this expedition, Berthollet and Monge 

 again distinguished themselves by their firm friendship for each 

 other, and by their mutually braving every danger to which any 

 of the common soldiers could be exposed. Indeed, so intimate 

 was their association, that many of the army conceived Berthollet 

 and Monge to be one individual, and it is no small proof of the 

 intimacy of these two savans with Napoleon, when it is learned 

 that the soldiers had a dislike at this corporate personage, from 

 a persuasion that it was at his suggestion they had been led into 

 a country which they detested. 



It more than once occurred in the course of the campaign, 

 that Berthollet's courage and integrity were put to a severe 

 test; and it is gratifying to reflect upon the manner in which he 

 acquitted himself. It happened on one occasion that a boat in 

 which he and several others were conveyed up the Nile, was 

 assailed by a troop of Mamelukes, who poured their small shot 

 into it from the banks. In the midst of this perilous voyage, 

 M. Berthollet began very coolly to pick up stones and stuff' his 

 pockets with them. When his motive for this conduct was 

 asked, " I am desirous," said he, " that in the case of my 

 being shot, my body may sink at once to the bottom of this 

 river, and may so escape the insults of these barbarians." 



On a conjuncture when courage of a rarer kind was required, 



