10 



BIOLOGICAL LECTURES. 



which this will take place depends upon the size and the degree 

 of rigidity which the ring has. Such vibratory motions consti- 

 tute the temperature energy of the atom. 

 But it is to be noted that with such kind of 

 motion there are parts of the ring which 

 have a maximum amount of motion and 

 other parts with minimum as at n. Sup- 

 pose, then, that for any reason such atoms 

 should attract each other, say gravitatively, 

 and come together, is it not evident that 

 they could adhere to each other only in 

 certain places, the so-called nodes n, of which there are four 

 when the vibrations are of this simplest type ? So each such 

 atom would have four points upon its circumference where 

 there could be adhesions. This is the same as saying that 

 so long as such an atom has any temperature its possibilities 

 of combination will be limited to the conditions of its vibratory 

 rate and this will be definite at a given temperature. Such 

 definite combination we call chemical combination, and the 

 combination itself a molecule. 



Follow out the possibilities of structure with such conditions 

 and one can see how cubes and hexagons result from the posi- 

 tions of the nodes of vibrating bodies, and thus orderly arrange- 

 ments, as exhibited in crystalline forms, follow, from a simple 

 mechanical process. 



Thus consider the rings in the dia- 

 gram (Fig. 2). The ring 2 touches upon 

 i at the node or place of least vibration, 

 and likewise its own nodes correspond in 

 position with those of i. In like man- 

 ner rings 3, 4, and 5 are similarly placed, 

 and each individual of the combination 

 could vibrate symmetrically without dis- 

 turbing its neighbors. This would also 

 leave each one free to swing as upon a hinge upon i. Imagine 

 then that 5 and 3 should swing upwards from the plane of the 

 page and lean over until they touched over i . It is plain to 

 see that their nodes would then come together and their 



FIG. 2. 



