Mr. Whelpley on the Idea of an Atom. 357 



. But such changes will not pervade all space, but extend to a 

 .^certain distance only from the centre; and the specific character 

 of the atom is determined by a certain fixed relation, between 

 the intensity of the forces {p and n) and the diameter of the 

 sphere in whose surface they are developed. Finally, the distri- 

 bution o( this intensity may be different, at different times. Thus, 

 if the {p and n) forces be developed, at the same instant, in three 

 diameters of the atom, corresponding with the three dimensions 

 of space, the intensities may vary in all three inversely as their 

 lengths : that is to say, one diameter of the spheroidal nucleus 

 may be longer or shorter than another ; but if it be longer, its p 

 and n will be less intense, and if shorter, more intense; so that 

 a single atom may have three different axes, of as many different 

 intensities, but whose intensities maintain a relation of compen- 

 sation among themselves. 



Such an atom may have a motion in regard to itself only, and 

 not in relation to any other; for it has parts, and occupies all, 

 space, and can vary in three distinct modes; to wit, in the size of 

 its nucleus, the intensity of its p and n powers, and the /orw of 

 their distribution ; but a change of one implies compensatory 

 changes in all. 



But it is of the first importance that if there be but one atom, 



or, if that atom be related only to itself, it can have but one axis 



C 

 in which p, n develope each other. For, let p — -;—n represent 



an axis of polarity, developed by the resolution of C into two 

 forces, whose centres of greatest intensity Bxe p and n] and let 

 p nhe the distance of these centres apart. The points n p are 

 movable toward and from C, in a vibratile motion. But, if n vi- 

 brates, p also must vibrate, and vice versa. If brought nearer 

 together, they are repelled by C, if farther separated, they return 

 to it ; for these motions violate their normal relation to space. 

 Let n vibrate toward C ; a certain time must then elapse, before 

 p can move away elastically on the other side, and, in that inte- 

 rim, C will have changed its position to the middle of the short- 

 ened axis p — C — n. Then follows an elastic motion of j9, equal 

 to the first one of w, and C follows it, moving as before in the 

 same direction, and so on. The centre (C) must continue to 

 move in this manner, and the force with which it moves is ex- 

 actly equal to the communicated impulse, (because all forces de- 



Vol. xLvm, No. 2.— Jan.-March, 1845. 46 



