The late Professor Henry Trimble has found the tannin present 

 (private communication) to be gallo-tannic acid. For an analysis of 

 the leave? I am indebted to Professor Procter of the Yorkshire College, 

 Leeds. 



Tanning matters absorbed by hide 8.2 per cent. 

 Non-tanning matters 13.0 " 



Insoluble at 60 F. 68.5 

 Water 10.3 



100.0 



The constituents of the leaves of the R. Metopium, closfcly resemble 

 those of the R. Coriaria, R.Cotinus SLXid Ji. rhodanthema^ in fact the 

 chemical examination may be said to confirm the classification of the 

 botanist. Thus 



Colouring Matter Tannin. 



R. (Joriaria contains Myricetin Gallo tannin 



R. Cotinas „ Myricetin Gallo tannin 



R. Metopium [Metopium Linnsei] „ Myricetin & Quercetin 



Gallo tannin 



R. rhodanthema [Rhodosphsera „ Quercetin Gallo tannin 

 rhodanthema] 



The stem of the R. Metopium was found to be devoid of colouring 

 matters of the quercetin group, but gallo and ellagi-tannic acids were 

 present. 



The Leaves of Haematoxylon Oampbachianum. 



As is well known, the stem of this plant constitutes the dve-stuif 

 logwood, and it was interesting to determine if a colouring matter was 

 present in the leaves, which possessed a close chemical relationship with 

 the haematoxylon of the stem. Such has already been shown to be 

 the case with the colouring matters contained in the stem 

 and leaves of the Rhus Gotinus and R, rhodanthema (loe. 

 cit.) For asupply of the leaves I am indebted to the kind- 

 ness of Mr. W. FavTc:^tt, Director of Public Gardens and Plantations, 

 Jamaica. Examination revealed the presence of a yellow colouring 

 matter which could be isolated in a similar manner to that present in the 

 R. Metopium. It formed glistening yellow needles soluble in dilute 

 alkalis with a pale green colouration, indicating some yellow colouring 

 matter contaminated with a trace of myricetin. Analysis gave number* 

 agreeing with those required by quercetin. C=5y.51; H=3.64. 



Theory for Cis Hio 0? — C=59.60 ; H=3.31. per cent. 



That it consisted almost entirely of this colouring matter appeared 

 erident by the examination of its acetyl-derivation which was obtained 

 as colourless needless melting at 191 ® . Analysis gave (v=58.3d; H= 

 4.30. 



Cii H6 O7 (Cj fls O5 ) requires C=58.59; H=3.90. 



