ON MATTER AND FORCE. 21 



attraction and power of combining with all 

 other elements. Every monad of ordinary 

 matter, he considers, is combined with a monad 

 of aether, forming a double conjugate compound 

 atom or unit. Compounds of several monads 

 may combine in several ways, forming dif- 

 ferent chemical elements. Every chemical 

 element is not a solid sphere, either in motion 

 or at rest, but consists of a definite number of 

 units, duads, centres of force, or monads of 

 matter and aether inseparably joined together, 

 arranged in some definite order, revolving 

 usually round some axis of rotation, and parted 

 from the nearest elements by a certain amount 

 of attached gether. Every such element must 

 in its very structure have four or five different 

 sources of contrast, from which a kind of 

 polarity may arise : contrasts of matter, aether, 

 and rotation, and these contrasts may be in- 

 cluded under the general term of polarity 

 For example, positive or vitreous electricity 

 may be an excess of attached aether ; negative 

 or resinous, a deficiency. 



Professor Clark Maxwell, in the Philosophical 

 Transactions, 1865, Part I, p. 460, says : " We 

 have, therefore, some reason to believe, from 



