442 D'ALEMBERT. 



rate summary of the dispute, in 176 2*. Again, when 

 Clairaut investigated the figure of the earth upon the hy- 

 pothesis of a variable density in the different zones, but the 

 same throughout each, D'Alembert was not satisfied with 



* I observe that Montucla (vol. iv. p. 72) considers D'Alembert 

 as the author of the anonymous attacks, but he is evidently preju- 

 diced against him. Indeed it is not clear that the editor, Lalande, 

 may not have modified some passages. A person who could write 

 the note about Clairaut might, indeed, be rather suspected of leaning 

 against him. But there is no being certain respecting one who is so 

 weak as Lalaude; one who, not content with constantly recording his 

 own small exploits in science, prints a motto under his portrait in the 

 edition of Montucla, purporting that though the heavens were under 

 his empire, and his genius penetrated through space, he yet reigned 

 still more in the hearts of men. His flippant note (vol. iv. p. 188,) 

 on Boscovich shews his dislike of D'Alembert. " Le Pere Bos- 

 covich ne fesait pas autant de calcul integral que D'Alembert, inais 

 il avoit bien autant d'esprit." He charges D'Alembert with per- 

 secuting the Pere all his life. But little reliance can be placed on 

 this assertion, at least if we may judge by the manifest falsehood of 

 his statement, that " D'Alembert attacked Boscovich in his ' Opus 

 cule,' vol. i. p. 246;" for all the attack consists in defending him- 

 self against an objection made by " an Italian geometrician of note 

 in the science." The utter incompetency of a person like Lalaude 

 to edit such a work as Montucla's, can hardly be conceived without 

 reading what he has done. Such ignorance or want of judgment is 

 inconceivable, as could make him call Priestley's 'History of Optics' 

 (so he terms it) a work of great importance, and one of its author's 

 best, while by speaking of it as a book in 813 4to pages, he shows 

 that he never had seen it; such ignorance as could also make him 

 speak of Priestley's " universal erudition," (vol. iv. p. 604, 5.) The 

 entire want of common care as to dates is shewn in his quoting 

 Black's experiments as published in 1777. The analytical expres- 

 sions so abound with errors, possibly of the press, but which 

 Lalande was incapable of correcting, that nothing can be more 

 unsatisfactory than reading the book ; nothing more tiresome than 

 using the formulas, and finding, after perhaps a laborious inves- 

 tigation, as has happened to myself, that there was a gross error in 

 1 hem 



