'272 REPoiJT— 1801. 



position ultimately taken up by the SO3H radicle appears to be deter- 

 mined by the beta-chlorine-atom, perhaps because the /8-salphonic acids 

 ai'e the most ' degraded ' products, thus : — 



CI CI CI CI 



/\/\ci /\/\ci /\/\ s/\/^- 



\x\/ ^\y\x x/v/^^ \/^ ^^^ 



s 



With reference to these examples it may be pointed out that the 

 apparent passage of the sulphonic radicle in the one case from one 

 nucleus into the other, in another from an alpha- into the contiguous beta-, 

 and in a third from an alpha- into the more distant beta-position, are 

 remarkable variations of the phenomenon of intramolecular mobility. 



There is a striking difference in the behaviour of the 1 : 4, 1 : 4', and 

 1 : 2 oa-dichloronaphthalenes, to which attention may be directed, the non- 

 formation of the acid containing a chlorine atom and the sulphonic radicle 

 in the 1:1' position being noteworthy, thus : — 



Cl Cl Cl Cl 



1 viflds 



s 



Cl 



01 

 Cl 



y\/\ 



Cl 



In the case of the 1 : 4 and 1 : 4' compounds the sulphonic radicle is 

 obviously influenced in two directions, and may be said to take up a 

 mean position. 



A case of isomeric change which at present appears altogether para- 

 doxical is that which is said to occur on heating sodium naphthionate 

 (NH, : SOsNa = 1 : 4) at 200-250°, whereby it is converted into the 

 isomeric 1 : 2-compound. 



The foregoing brief reference to the work of the Committee will 

 suffice to show that the study of naphthalene derivatives is fraught with 

 interest, more especially as it is to be anticipated that results of general 

 application will be obtained in the course of the inquiry. 



