2 Biographical Account of [Jan. 



respecting it ; and it is probable that he was also impelled to the 

 change by his speculative turn of mind, which led him to prefer 

 a mode of life in which he would be less confined to a regular 

 routine of business. The decided bent of his genius was indeed 

 for theory and speculation ; and of this he gave a very unequi- 

 vocal specimen, in his " Essay on the Principles of Natural 

 Philosophy," which he wrote while he was still under his father's 

 roof. It contained so many free sentiments, on various topics 

 in which the feelings and prejudices of mankind are the most 

 intimately concerned, that the booksellers of Paris would not 

 venture to publish it; but it appeared at Geneva in 1778. The 

 work was reprinted in 1787, and again in 1805, having undergone 

 successive improvements in each edition. In this essay he dis- 

 cusses a variety of the most abstruse metaphysical questions, and 

 gives his sentiments upon all of them with the most perfect con- 

 fidence, although he not unfrequently 'maintains opinions 

 directly opposite to those which are commonly regarded as the 

 most important and the best established. 



Upon quitting the paternal roof, he seems to have determined 

 to pass the remainder of his life in a state of perfect freedom 

 from all restraint ; and with this intention he renounced all his 

 claim upon the family property, on consideration of receiving a 

 moderate annuity. He resolved never to enter into the matri- 

 monial state from the same feeling, and partly, as it appears, 

 from the gloomy and melancholic cast of his mind, winch led 

 him to doubt whether life ought to be regarded as a good, and 

 consequently whether it was consistent with benevolence to 

 bring human beings into existence. The peculiar traits of his 

 character, which had displayed themselves at a very early period 

 of life, were now become more confirmed ; and, what was 

 originally an unusual degree of gravity and sedateness, had now 

 degenerated into spleen and austerity. Having discarded all his 

 cares of a personal and private nature, he repaired to Paris, 

 associated himself with the literary men of mat place, and 

 henceforth had no business or occupation but science. About 

 the year 1780 he published his " Physiological Views ; " a work 

 which, like the former, was full of theory, and in which he in- 

 dulges in the most unbounded freedom of speculation. Among 

 other opinions which he broached in this work, it is maintained 

 that animals and vegetables are produced by the crystallization 

 of the semen, exactly in the same manner as minerals are by the 

 accretion of their particles ; and extravagant as tins opinion may 

 appear, it is only a specimen of many others of a similar kind 

 that might be extracted from his works. 



Soon after his removal to the metropolis, he became a frequent 

 contributor to the Journal de Physique ; and in the year 1785 he 

 became the editor of it, an office which he retained until a very 

 short time before his death. In many respects he was well 

 adapted for this office ; he was laborious, well informed, and 



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