136 MEMOIR OF DR. DALTON, AND 



divisible. It does not of necessity cease to be so, as we may 

 readily believe, in the constancy of these points ; but we may 

 also imagine the power dispersing in various directions, and 

 the absolute amount of force existing in one particle to lie 

 diffused throughout the whole world, or any given amount 

 of space. 



When the particles are formed, Boscovich deals with 

 them exactly as with matter, formed of indestructible atoms. 

 " Thus he supposes that the points of matter alternately 

 attract and repel each other, according to the distance that 

 separates them, until they either come very close to, or 

 are removed to a comparatively great distance from each 

 other; in the former case they are repelled, in the latter 

 attracted; the former force preventing mutual contact, the 

 latter, which, when considered as acting between the earth 

 and bodies upon it, is no other than gravitation, drawing 

 them all together." 



The Encyclopedie Methodique* in an article written by 

 G. Morveau, 1786, may be presumed to give the advanced 

 opinion of chemists. He says, 



" Are there really different degrees of saturation of the same 

 salt ? or is not the union which it contracts with that portion 

 which exceeds the point of saturation, the effect of super- 

 composition, as in combination with a third foreign body? 

 This is a question which merits all our attention, not only 

 because it is of interest in the general theory of chemical 

 attraction, but rather because it is of importance that we 

 should understand what is the character of the affinity before 

 we attempt to submit it to calculation, or evejn deduce a satis- 

 factory explanation of the phenomena which depend on it. I 

 confess that the idea of divers degrees of saturation of one 

 body with another appears to me repugnant to all the notions 



• Vol. I., p. 660-1. Encyclopedie Methodique. Chymie Pharmacie et 

 Metallurgie. Paris, 1786—1815. 



