Bacteriologie. 291 



Smith, H. G., On the absence of Gum, and the presence of 

 a new Diglucoside in the Kinos of the Eucalypts. (Abstr. 

 Proc. roy. Soc. N. S. Wales. 1904.) 



In this paper, which is the first of a series dealing with Euca- 

 lyptus kinos, the author shows that the supposed gum occurring in 

 many Eucalyptus kinos is not gum but a peculiar tannin diglucoside. 

 The insolubilit}" in alcohol of this substance seems to have been the 

 only reason for considering it to be gum. Professor Wies n er ^) 

 stated that it was closely allied to Acacia gum, and J. H. Maiden 2) 

 later formed one of his Eucalyptus kino groups (the Gummy Group) 

 upon its presence. It does not appear possible to obtain it in a crystal- 

 lised condition, nor could it be removed from aqueous Solution by 

 miscible solvents. It was obtained in as pure a condition as possible 

 by repeated precipitation by alcohol from concentrated aqueous Solu- 

 tions. When dried and powdered, it was of a cinnamon colour, and 

 this colour was not removed by boiling with animal charcoal. It is 

 very soluble in water, and when boiled with acid for some time a 

 "kino red" is formed in quantity^ a sugar being separated at the 

 same time. The "kino red" dyes mordated cloth a series of browns, 

 alumina giving the best colour. When fused with potash it forms 

 protocatechuic acid but not phloroglucinol. The sugar had norotation, 

 was reduced by Fehling's Solution readily, was slowly but entirely 

 fermented by yeast, and gave an osazone soluble in hot water, and 

 which melted at 176—178° C. Were it not that it was inactive to 

 light it might, from these reactions^ be supposed to be melibiose, 

 which is formed from melitose (Eucalyptus sugar) by hydrolysis , 

 levulose being split off at the same time. This glucoside, for which 

 the author proposes the name Emphloin (as it principally occurs in 

 the bark of certain species) is found in almost a pure condition in 

 those Eucalypts known as "Ironbarks." The kinos of the "Stringy- 

 barks" and of the "Peppermints," although consisting of the same 

 tannin, do not contain sugar and are not glucosides, but the author has 

 already isolated a glucoside, Myrticolorin, from the "Stringybarks," 

 the sugar of which is glucose. This kino glucoside is practically a 

 bark product, occurring in species which do not appear to give 

 Eucatyptus Manna. Melitose however, is found in the bark of certain 

 species in which the tannin is principally located in the wood, as in 

 E. pimctata. For these reasons the author thinks that melitose itself 

 should be considered a glucoside, the third glucose molecule taking 

 the place of the tannin in the glucoside. The quantitative results, 

 and the relative astringent values show the substance to contain an 

 equivalent to two glucose molecules. Although entirely precipitated 

 by gelatine, the glucoside has very slow action on hide, and thus the 

 sluggishness of "Ironbark" liquors is accounted for. It now remains 

 to devise a method whereby the glucoside may be cheaply hydrolysed, 

 and thus the tannin in the bark of E. sideroxylon , for instance, be 

 made availade for tanning purposes. Smith. 



1) Pharm. Journ. [3] 2, 1871. 



^) Proc. Linn. Soc. N. S. W., 1899 and 1891. 



