MOLECULAR MAGNITUDES. 655 



that the magnifying of any object while in motion will exhibit that 

 motion increased in velocity just as many times as the diameter of the 

 object is augmented. Suppose we had at our command an instrument 

 competent to amplify the atoms to the one-fiftieth of an inch in diam- 

 eter : in the case of the hydrogen-atom the necessary magnifying 

 power would be 10,000,000 diameters, under which power the atoms 

 would have their motions enhanced by the same multiple, and we 

 should then be called upon to examine an image the fiftieth part of 

 an inch in diameter plunging across the field of vision five hundred 

 million times faster than the flight of a cannon-ball. 



It follows, since human skill is incompetent to penetrate by any 

 mechanical means into the internal structure of matter, that we shall 

 be compelled to direct our labors to other modes of investigation if 

 we would know more of the atomic structure of matter, possessing as 

 it does a minuteness far surpassing the analytical power of the micro- 

 scope ; in fact, so hopelessly ultra-microscopic as to elude all other 

 processes except that of mathematics and experimental investigation. 



The question of the infinitely large and the immeasurably small 

 has engaged the attention of philosophers since the days of Democ- 

 ritus. Modern investigators are, however, in possession of experi- 

 mental data that aid them in arriving at facts with ever-increasing 

 accuracy. We have the atomic theory first placed upon a substantial 

 basis by Dalton, which treats of the atomic constituents of matter, 

 and gives to each atom a definite size and weight, and establishes the 

 proposition that atoms combine to form molecules, and that molecules 

 aggregate to masses. We have also the kinetic theory of gases, 

 which has been placed upon a purely mathematico-scientific footing, 

 as has also the department of hydro-kinetics ; and experiments within 

 these departments are accumulating evidence concerning the atomic 

 and physical structure of matter. 



The kinetic theories are based upon the conception that these 

 particles or atoms are in constant motion among themselves ; and it 

 assumes, also, that their movements have an infinite series of veloci- 

 ties in all conceivable directions, but with varying degrees of inten- 

 sity. This idea of atomic and molecular motion puts us in possession 

 of an important factor for determining the causation of all physical 

 phenomena. Of course we do not presume to say that the atom is 

 the primordial or ultimate constituent of matter, for there are many 

 evidences to show that the present list of sixty-five elements of mat- 

 ter may not be elementary at all, but isomeric compounds of one or 

 more simpler constituents. 



The question might here be asked, '' Hoav does the physicist know 

 anything of the relative size of atoms and their vibratory motions?" 

 The answer is : by mathematical deductions, based upon the behavior 

 of gases ; by experimental evidence, principally in the domain of ra- 

 diant heat ; also in the interdifiusion of liquids and gases. Researches 



