1O2 



reaction of this group is its combination with chlorine, th 

 quantitative features of which have been the subject of careful 

 investigation. The chlorinated lignone is a body of 

 definite and uniform composition, represented by the empirical 

 formula C 19 H, 8 C1 4 O9. It is still a complex containing a 

 quinone chloride, allied to mairogallol (C^HyClnOio) and 

 leucogallol products of chlorination of pyrogallol, under care- 

 fully regulated conditions in combination with the furfural- 

 yielding complex. The combination with the chlorine is 

 attended by molecular hydration, in consequence of which 

 the chlorinated lignone is split off, more or less, from its con- 

 densed union with the cellulose. 



As in the preceding case, therefore, we are dealing with a 

 reaction which, though perfectly definite and characteristic of 

 constituent groups of the parent molecule, cannot be inter- 

 preted in terms of these groups without introducing hypothe- 

 tical considerations. The reaction will be discussed subse- 

 quently from this point of view. In the mean time it is sufficient 

 to point out that the reaction is uniform in its empirical features, 

 that these may be quantitatively studied, giving what we may 

 term the constants of chlorination of the fibre-substances, viz. 

 (i) the chlorine combining with the hexene groups of the 

 fibre-substance as quinone chloride ; (2) the chlorine com- 

 bining with hydrogen, and set free as hydrochloric acid. It is 

 found, in the case of jute, that (i) and (2) are approximately 

 equal, and therefore that the reaction is unattended by second- 

 ary oxidations of the fibre-constituents to any notable extent. 



The following are the details of the methods of estimating 

 these constants of chlorination. 



(i) Volume of chlorine disappearing in chlorination. The 

 method of observation is fully described in J. Chem. Soc. 

 1889, 169. The fibre-substance is prepared in the usual way, by 

 previously boiling for 10-15 minutes in dilute alkaline solution 



