159 



lost its significance, as far as regards the crystallographical descrip- 

 tion of the phenomena observed: the whole crystal, endlessly 

 extended in all directions, behaves as one single gigantic crystal- 

 molecule. There is, however, at present no reason why the existence 

 of special forces preserving the atomic relations previously existing 

 in the separate chemical molecule should be denied, as has been 

 done in recent times by a number of physicists. l ) 



28. One of the most important problems of the immediate 

 future must be to get information about the special connection 

 between the forces which hold together the regular arrangements 

 in space of the atoms composing the crystalline medium, and the 

 chemical forces or valencies supposed to be the causes of the chemical 

 architecture of the molecule itself. Certainly there must be an intimate 

 relation between them, as was for instance seen in the case of diamond 

 and graphite, although we do not know at present how to attack 

 this problem properly. The modern views on coordination, as proposed 

 by Werner, seem to open a road in this direction: the forces which 

 govern the structure of coordinative compounds appear to differ, 

 not principally at least, from those supposed by the elder atomists. 



When we shall have gone so far as to have found out this relation, 

 the significance of the symmetry-principle for the mode of action 

 of the chemical forces and for the stereometrical configuration of 

 the chemical molecule itself, will then doubtless be seen in a new 

 light, thus extending the views expounded in the previous chapters 

 to the mutual actions of the ultimate particles of inanimate matter. 



29. In the preceding chapters we have also had full opportunity 

 to draw the attention of the reader to the part which the principle 

 of symmetry plays in living nature. The questions relating to this 

 have two sides : either we can study the special symmetry of the diffe- 

 rent organs of living individuals ; or we can regard more particularly 

 the symmetry of the mutual arrangement of such organs. Hitherto 

 we have dealt more exclusively with the first side of the question, 



97 1 10, have made some suggestive suppositions about the preservation of "chemi- 

 cal molecules" in crystalline media; cf. also: R. Gross, Centralbl. f. Miner., (1918), 

 p. 1. 



1) From the experiments with R on t gen-rays it can only be concluded, 

 that for the description of the diffraction-phenomena observed, it appears 

 Mwnecessary to allow for the eventually existing chemical forces between the 

 atoms of one and the same chemical molecule. However, it is not proved by these 

 investigations, that the more intimate relations existing before between the atoms 

 of the chemical molecules, should have totally disappeared in the crystal. 



