ABSENCE OF GUM AND PRESENCE OF A NEW DIGLUCOSIDE. 23 



South Wales for 1889 and 1891, it was shown that Eucalyptus 

 kinos can be divided roughly into groups, judged by their 

 physical appearance, and by their behaviour in water and 

 alcohol. He there divides them into three classes, the 

 Turbid, the Ruby, and Gummy groups. As gum is absent 

 in these kinos, the gummy group of course cannot stand, 

 and for various reasons it would be advisable to discard 

 the turbid group also. This general grouping lias perhaps 

 served its purpose by directing attention to their marked 

 differences, but it would not be advantageous to future 

 study, if this arrangement were longer retained, and no 

 useful purpose would be served by so doing. There are 

 several tannins in the Eucalyptus kinos, and the astringent 

 principles of these exudations, together with the other 

 allied substances, must necessarily be the dominant feature 

 governing their classification, and the arrangement thus 

 becomes purely a chemical one. 



The numerous constituents isolated from Eucalyptus oils 

 were found to have a gradual increment, until the maxi- 

 mum was reached in certain species. So it is with the 

 kinos, and most of them are, therefore, a mixture of various 

 tannins and allied substances, and there is no line of 

 demarcation sharply separating one class from another. 

 Even the distribution of the kinos in the plants themselves 

 is not similar; in some of the "Ironbarks," for instance, 

 as E. crebra and E. sideroxylon the kino is largely distri- 

 buted throughout the bark itself, and consequently this is 

 often charged with it, and then has some value for technical 

 purposes, as in tanning. In the " Stringybarks " the 

 astringent substance appears to be largely contained in 

 the timber. It is worth notice also, that the inner layer 

 of the bark of most of the true 1 " Stringybarks " contains 



1 This term is used to distinguish these trees from such a species as 

 E. resinifera (one of the Mahoganies), whose bark is also a ''Stringy bark" 

 in character, but the kino is allied to that of the " Ironbarks." 



