ABSTRACT OF PROCEEDINGS. XXI. 



kinos which give this coloration, also a sparse precipitate 

 slow to form, with iodine in potassium iodide, and a com- 

 paratively small amount of the copper salt insoluble in 

 ammonia, all contain in excess this tannin, and the tinctures 

 from these do not gelatinize. The astringency value of the 

 several kinos also varies considerably, those giving the 

 green coloration being the least astringent. The same 

 species of Eucalyptus always gives a similar kino, and in 

 this constancy follows the rule found to be characteristic 

 of the essential oils of identical species. Those Eucalypts 

 which give oils containing phellandrene, all appear to exude 

 kinos which give the violet coloration with ferric chloride, 

 and they, of course, gelatinize in tinctures most readily. 

 All kinos contain mixed tannins, although as the species 

 branch off through the various channels, certain of the 

 tannins diminish in amounts either in one direction or 

 another. The author shows that the addition of a small 

 amount of formaldehyde to the tincture will determine in 

 a few days whether a kino will gelatinize or not. Acet- 

 aldehyde also acts in the same way, but is slower in its 

 action, and as a test not so satisfactory. So far, four 

 Eucalyptus kinos have been found which do not gelatinize 

 in tinctures, and they all have a high astringency value. 

 They are obtained from E. microcorys, E. calophylla, E. 

 eximia and E. maculata. The tinctures of the two last, 

 however, give precipitates when diluted with water, that 

 of E. calophylla gives a turbidity only, while that of E. 

 microcorys does not give a turbidity even on the addition 

 of a large amount of water. It thus appears that the 

 difficulty of gelatinized tincture of kinos may be overcome 

 by using these Eucalyptus kinos, and that without the 

 addition of corrigents like glycerol. The paper includes 

 tables illustrating the reactions of the several kinos, and 

 also giving full data in reference to the gelatinization of 

 the tinctures. 



