446 



Mr. S. A. Sworn on the Constitution 



From Thomsen's symbol. 



m 



s' 



From Ladenburg's symbol 

 (octahedral). 



Meyer's symbol. 

 III. 



Naphthalene as thus constituted (II.) could hardly be said 

 to consist of two aromatic nuclei. That it does consist of two 

 such nuclei is evident from the fact that, like benzene, it has 

 an abnormally low molecular volume, and gives substitution 

 products by direct nitration and sulphonation. Moreover, in 

 the formation of these derivatives the action appears to follow 

 as closely as possible the laws of substitution which hold for 

 benzene derivatives. Hartley found the absorption of the 

 ultra-violet rays characteristic of benzene to be even greater 

 in the cases of naphthalene, anthracene, and phenanthrene. 



The same difficulties hold with regard to the other conju- 

 gated bodies. Unless ortho-linkage is set up it is difficult to 

 account for the ascertained constitution of phenanthrene, 

 more especially its formation from stilbene. 



I may quote the formulas which might be assigned to phen- 

 anthrene and pyrene. 



Phenanthrene, C l4 H 10 

 (from Thomsen's symbol). 



CH ch 



Phenanthrene, O l4 H, 

 (from Meyer's symbol). 



