LIFE FROM A PHYSICAL STANDPOINT. 9 



without other help. He may not trouble himself to find an 

 explanation, but if he does concern himself to find a mechani- 

 cal explanation, he needs to know more about atoms and mole- 

 cules that he may perceive how certain kinds of motions neces- 

 sitate orderly arrangment. 



That the atoms of matter have internal vibratory movements 

 is proved, I st, by their elasticity in the gaseous form ; 2d, by 

 the uniformity of the wave length of light when made incan- 

 descent, as shown in the spectrum of a gas, indicating as 

 plainly as can be that the atoms have their regular rates of 

 vibration, an enormous number per second. As the velocity 

 of light is 186,000 miles per second, a wave-length the fifty- 

 thousandth of an inch long implies that atoms that produced 

 it vibrated as many times a second as the fifty-thousandth of an 

 inch is contained in 186,000 miles, something like 600 millions 

 of millions. If one cannot conceive such a number, he is com- 

 pelled by his arithmetic to believe it represents the truth. 

 But the thing of importance here is to picture to one's self the 

 vibratory motion itself, and here one must have recourse to 

 mechanical models. It may be well to remark that the idea of 

 hard, round, or spherical atoms has been abandoned by physicists 

 as having no probability at all, but whether atoms have one form 

 or another they certainly have these vibratory rates, and one 

 may make his mechanical models in any way that shall not be 

 incompatible with such physical properties as atoms are known 

 to possess. 



Within the past 20 years the evidence has been fast accu- 

 mulating which gives credence to what is known as the vortex 

 ring as being the form of the ultimate atom. The puff of 

 smoke and steam from a locomotive which goes sailing as a 

 ring high in the air, wriggling, vibrating and twisting con- 

 stantly, but maintaining its ring shape in spite of these, is an 

 example. Such a ring has form, elasticity, momentum, energy, 

 and other physical properties. So if one considers what vibra- 

 tion in such a ring consists in he will have a fair conception of 

 it in an atom. Its diameter lengthens in one direction until 

 its shape is elliptical, a b (Fig. i), then it swings back into 

 an ellipse at right angles to the first, c d, and the rate at 



