1818.] M. Le Sage. 247 



year. During a long period he was afflicted, to a very great 

 degree, with sleeplessness, from which he not only experienced 

 the ordinary unpleasant consequences, but his intellectual facul- 

 ties were seriously affected, and reduced at times to a state of 

 extreme incapacity. But this unhappy malady was only of tem- 

 porary duration ; and whenever he was freed from it, his mind 

 retained all its vigour, and enabled him to resume his studies 

 with full effect. Kis exemplary diligence, and his habits of order 

 and regularity, which were extended to all subjects in any way 

 connected with his literary pursuits, enabled him to make a 

 greater degree of proficiency in many abstruse departments of 

 science than even most individuals who had not such obstacles 

 to oppose their progress. We have already alluded, on more 

 than one occasion, to the remarkable deficiency of his memory ; 

 this defect remained with him through life ; for although by 

 extraordinary method in arranging his ideas and his knowledge, 

 he was able to recal and make use of them at pleasure, it all 

 depended upon the employment of a technical system, which, 

 while it served as a substitute for memory, would tend by its 

 operation to prevent the improvement of the faculty itself. 



But although Le Sage was a man of so much diligence and so 

 much method, yet he accomplished less, perhaps, than might 

 have been expected from this combination of qualities. This 

 depended upon two circumstances : the originality and profun- 

 dity of his views, which prevented him from proceeding rapidly 

 in his course; and the fear which he felt of committing his works 

 before the public tribunal in an imperfect form. What he pub- 

 lished were short treatises, comparatively of little importance, 

 often written on particular occasions, as prize essays, or insulated 

 memoirs, inserted in the Transactions of various learned societies. 

 Of these detached productions, perhaps, the most important are, 

 " Essai sur l'Origine des Forces Mortes," which was presented 

 to the French Academy of Sciences, but not published by 

 them ; and " Essai de Chimie Mechanique," in which he endea- 

 voured to explain all the phenomena of chemical affinity by the 

 operation of an impulsive fluid, which obtained half the prize 

 that was proposed by the Academy of Rouen. Besides these, 

 and some smaller tracts, which were published during his life, 

 he maintained a very extensive correspondence with many of 

 the most learned men of the age, who appreciated his merit and 

 valued his friendship; and he left behind him a number of works, 

 in a more or less perfect state, which were the unfinished results 

 of his studies and meditations, and which he appears tu have 

 regarded as the basis of his future fame, although, by a strange 

 inconsistency, he omitted the essential means of deriving t in- 

 desired object from them. His most considerable unpublished 

 work, that which contains his matured opinions on his favourite 

 topic, is his " Traite des Corpuscules Ultramondains." The 

 "hject of this elaborate performance is to account for the pheno- 



