98 HENRY G. SMITH. 



solution and appears to start from the particles of kino 

 which are always left undissolved. Mr. S. J. Johnston, 

 b.a., b.sc, of the Technological Museum is making an investi- 

 gation of this organism, and its description will appear later. 



The following list gives the general chemical reactions 

 and astringency values of the Eucalyptus kinos dealt with 

 in this paper, and it will be seen that associated kinos 

 behave similarly. In no instance did the time allowed for 

 precipitates to form extend beyond one hour. The method 

 of determining the astringency values was described in the 

 previous paper on the kino glucoside, the strength of the 

 solution being one gram per litre. 



The method adopted for taking the colour reaction with 

 ferric chloride was to have a full test tube, standing before 

 a window, and to allow one drop of the reagent to fall 

 through the solution without agitation ; the strength of 

 the kino solution for this test was 0*33 gram per litre. The 

 best results were obtained with a solution of this strength. 

 The other tests were made with kino solutions of one gram 

 per litre. 



Most Eucalyptus kinos contain mixed tannins and the 

 reactions are, therefore, largely governed by the predomin- 

 ant tannin present. The tannins which give violet and 

 green colorations with ferric chloride gelatinize in tinctures, 

 the former much the more readily, but the one giving the 

 blue coloration does not gelatinize. It is also possible to 

 detect the diminution or otherwise of the individual tannins 

 by the reaction with ferric chloride and by the astringency 

 value and the gelatinization test. The changes that take 

 place in the colour reaction, together with the results of 

 other reagents are not given in the table, as they have 

 little bearing on the results of gelatinization. Those 

 Eucalyptus kinos that give a blue coloration with the ferric 

 salt, a sparce precipitate slow to form with iodine in 

 potassium iodide, and a comparatively small amount of the 

 copper salt insoluble in ammonia, all contain in excess the 

 tannin which does not gelatinize in tinctures. 



