588 The Structure of Organic Crystals [May 19, 



atom. When as in acenaphthene a complex group of atoms is 

 attached to one side of the molecule, and the crystal to our surprise 

 becomes more regular than before, right-angled instead of oblique, 

 we find an explanation in the fact that there are now four molecules 

 within the cell instead of two, and that by sloping in pairs in opposite 

 ways they increase the symmetry of the crystal. 



These examples may serve to show how an attempt may be made 

 to arrive at a knowledge of the structure of these organic compounds 

 with, I think, some success. It seems justifiable to see in the rigid 

 and queerly shaped molecule attaching itself at definite points, and 

 with great precision of orientation to neighbouring molecules, a cause 

 of the immense multiplicity and, at the same time, the accurate form 

 of organic crystals, and indeed to find here the foundations of organic 

 chemistry. 



[W.B.] . 



