iiic*. if.] DISSERTATION SECOND. 53 



stances, so as to be more bewildering to the imagination, 

 and more difficult either to apprehend or to refute. 1 



John Bernoulli was at first of a different opinion from 

 his friend and master, but came at length to adopt the 

 same, which, however, appears to have gone no farther till 

 the discourse was submitted to the Academy of Sciences, 

 as has been already mentioned. The mathematical world 

 could not look with indifference on a question which seem- 

 ed to affect the vitals of mechanical science, and soon 

 separated into two parties, in the arrangement of which, 

 however, the effects of national predilection might easily 

 be discovered. Germany, Holland, and Italy, declared for 

 the vis viva; England stood firm for the old doctrine; 

 and France was divided between the two opinions. No 

 controversy, perhaps, was ever carried on by more illus- 

 trious disputants ; Maclaurin, Stirling, Desaguliers, Jurin, 

 Clarke, Mai ran, were all engaged on the one side, and 

 on the opposite were Bernoulli, Herman, Poleni, S'Graves- 

 ende, Muschenbroek ; and it was not till long after the 

 period to which this part of the Dissertation is confined, that 

 the debate could be said to be brought to a conclusion. 

 That I may not, however, be obliged to break off a sub- 

 ject of which the parts are closely connected together, I 

 shall take the liberty of transgressing the limits which the 

 consideration of time would prescribe, and of now stating, 

 as far as my plan admits of it, all that respects this cele- 

 brated controversy. 



A singular circumstance may be remarked in the whole 

 of the dispute. The two parties who adopted such diffe- 



1 To mere pressure, Leibnitz gave the name of vis mortua, 

 and to the force of moving bodies the name of vis viva. The 

 former he admitted to be proportional to the simple power of the 

 virtual velocity, and the second he held to be proportional to the 

 square of the achtal velocity. 



