PROPEEDINGS OF SECTION B. 91 



similar to that in the members of Class I., but they all cousist largely 

 of the glucoside, Emphloin, which constituent is responsible for their 

 insolubility in alcohol. The kinos of the typical " ironbarks " are 

 representative of this class, but E. saligna, E. hotryoides, and a few 

 others also contain the glueoside in some quantity, but are somewhat 

 intermediate in character. The kinos of this class mostly give a red- 

 brown colouration with ferric chloride, soon becoming much lighter 

 towards the top of the tube, eventually forming a very small brown- 

 grey precipitate. With ferric acetate, however, the colour is blue- 

 violet, and eventually a copious dark-bluish precipitate forms. Ferric 

 chloride has thus a greater discriminative value with eucalyptus Idnos 

 than has ferric acetate. The kinos of Class IV. (1 gram per litre) give 

 a slight turbidity with bromine water, due to the free tannin present, 

 and this is also the case with iodine ; they thus difier from those of 

 Class I., otherwise they agree in general reactions. The kinos of this 

 class also gelatinize readily, and have only a moderate oxidizing value, 

 the astringency value ranging between 400 and 500. They have a 

 very slow action upon hide substance, although precipitated by gelatine. 

 Representatives of this class are obtained from the following species ; — 



E. siderophloia E. crebra E. sideroxylon 



E. paniculata E. saligna E. botryoides 



E. resinifera E. patentinervis E. robusta 

 E. intertexta 



E. afpnis closely approaches this group. 



It is most probable that the kinos of all the eucalypts will be 

 found to fall into one or other of the above classes, but so many of 

 them are intermediate in character, due to the mixture of constituents, 

 that it is difficult sometimes to decide to which class or intermediate 

 group some of them belong ; advantage may then be taken of their 

 differences in astringency values. 



Freshly exuded kinos naturally contain more water than when 

 dry, and wood debris often occurs in the more friable kinos ; any ill- 

 effect from such disturbing influences can, however, be practically 

 eliminated with ordinary care. 



Summary. 



From the results of this inquiry the following replies may be given 

 to the questions previously enumerated : — 



(a) Eucalyptus exudations render some assistance in a phyto- 

 chemical study of the genus, but not nearly to the same extent 

 as do the oils, as slight differences in the constitution of 

 the kinos of allied species cannot easily be determined. 

 One illustration will suffice to show how the kinos may 

 assist. E. intertexta is placed by Mr. Maiden (Crit. Rev. 



