58 VOLTAIRE. 



is inviting to visit them, that " plays are made daily, 

 and Jupiter's satellites observed nightly (Cor. Gene- 

 rale, iii. 184) ; that they will be free to pass the 

 mornings in their own apartments, and will hear read 

 in the evening the compositions of the day ; and that 

 the Marchioness 'joue on i'opera, ou la comeclie, on 

 la comete ' " (ib. 312). Indeed Voltaire himself exhi- 

 bited perhaps the most remarkable instance of varied 

 and versatile talents on record, by producing, within 

 the same three or four years, the Newtonian ' Ele- 

 ments/ his prize essay on ' Fire,' ' Zaire,' ' Alzire,' 

 ' Mahomet,' ' the Discours sur 1'Homme,' more than 

 half of the ' Pucelle,' the ' History of Charles XII.,' 

 besides an endless variety of minor pieces, and some 

 volumes of correspondence in prose and verse. The 

 'Pucelle' was begun to amuse him while obliged to 

 fly from Paris in 1734 by the persecutions he suffered 

 on account of the ' Letters on England.' 



It was at Cirey, then, with a few weeks passed in 

 'Sgravesande's society at Leyden, that Voltaire com- 

 posed, and finally prepared for publication,his 'Elements 

 of the Newtonian Philosophy,' as well as his ' Essay on 

 Fire ;' and of both these works we may now treat. 



In order to estimate the merits of the work on Sir 

 Isaac Newton's discoveries, we must first consider the 

 state in which it found the Newtonian system on the 

 Continent ; next, the helps which he had in writing it. 

 There can be no doubt that Clairault, destined 

 afterwards to confirm the theorv of the moon's motions, 







though at first, with others, to undergo a temporary 



error upon the subject, destined also to join with 



D'Alembert and Euler in explaining the disturbing 



forces by working out the problem of the three 



