PRIMARY CONCEPTS OF MODERN SCIENCE. 93 



manner a train of ether-waves to their source; remembering at the 

 same time that your ether is matter, dense, elastic, and capable of mo- 

 tions subject to and determined by mechanical laws. What, then, do 

 you expect to find as the source of a series of ether-waves ? Ask your 

 imagination if it will accept a vibrating multiple proportion — a nu- 

 merical ratio in a state of oscillation ? I do not think it will. You 

 cannot crown the edifice by this abstraction. The scientific imagina- 

 tion, which is here authoritative, demands as the origin and cause of a 

 series of ether-waves a particle of vibrating matter quite as definite, 

 though it may be excessively minute, as that which gives origin to a 

 musical sound. Such a particle we name an atom, or a molecule. I 

 think the seeking intellect, when focussed so as to give definition with- 

 out penumbral haze, is sure to realize this image at the last." 



The import of these sentences is plain. It is that an ethereal or 

 other atom, or a molecule, is related to its vibratory motion just as 

 any ordinary body is related to its movements of translation — as a 

 stellar or planetary body, for instance, is related to its movements of 

 rotation or revolution ; and that, just as the conception of the stellar or 

 planetary body of necessity precedes the conception of its rotary or 

 revolutionary motion, so also the conception of the atom or molecule 

 of necessity precedes the conception of the vibratory motion whereof 

 light, heat, electricity, chemical action, etc., are known or supposed to 

 be modes. In other words : to make the existence of matter, such as 

 we deal with in action and in thought, conceivable, we are constrained, 

 according to Tyndall, to assume ultimate material particles as pre- 

 existing to those motions or manifestations of force which are appre- 

 hended as light, heat, electricity, chemical action, etc. 



In order to preclude all possibility of misunderstanding, it is per- 

 haps well to call attention to the fact that, while Tyndall speaks in terms 

 only of the relation of the ether to its vibratory motion, it is evident 

 from his own language that this is meant as an illustration or exem- 

 plification of the relation of all matter to any or all motion whatever. 



Now, let us for a moment contemplate an ultimate particle of mat- 

 ter in this state of existence in advance of all its motion. It is with- 

 out color, and neither light nor dark ; for color, lightness, darkness, 

 etc., are luminar affections, and, according to the received mechanical 

 theory of " imponderables," of which Prof. Tyndall is a distinguished 

 champion, simply modes of motion. It is similarly without tempera- 

 ture — neither hot nor cold ; for heat also is a mode of motion. For 

 the same reason it is without electrical or chemical properties — in 

 short, it is utterly destitute of all those properties in virtue of which, 

 irrespective of its magnitude, it could be an appreciable object of 

 sense, unless we except the properties of weight and extension. But 

 weight is a mere play of attractive forces ; and extension, too, is known 

 to us only as resistance, which in turn is a manifestation of force, and 

 thus a phase of motion. Extension per se, abstract extension, cannot 



