M. Seguin on the Effects of Heat and Motion. 277 



them all the generality of which they are susceptible. If, as 

 our celebrated astronomer Laplace supposes, the different 

 planetary systems owe their formation to a material mass mi- 

 nutely divided, which, in obeying the single law of being at- 

 tracted in the inverse ratio of the square of the distance, the 

 molecules, at the origin of their motion, obeying their gravity 

 to reunite at the centre of the mass, and experiencing pertur- 

 bations from the neighbouring molecules, ought to approach 

 each other more and more, describing curves which satisfy the 

 integral conservation of the motion which they have acquired 

 during the passage they have made. Each particular sys- 

 tem will, by this means, have made part of another system, 

 with the power of being able, according to certain laws which 

 are unknown, to give or receive from it a certain quantity of 

 motion, but with the express condition that the t lal sum can- 



