19 



again. No one here has treated the tree to any kind of scientific culture 

 and notwithstanding the fact that the same soil has been cropped con- 

 lecutively for over a hundred years there is as yet no sign of decadence 

 nor does a necessity yet arise for artificial manure. 



" There have been a few instances of a disease due to a small insect 

 which perforates the pod and stoix its growth, but this has only occur- 

 red in very dry seasons and in the lower region of the country, but 

 otherwise there has been no disease which has attacked the tree or fruit 

 here ; a failure of the crop is almost invariably due to either a very dry 

 season with strong sunshine shrivelling up the flower, or to a very 

 heavy rainy season in which the tree is often enveloped in water for 

 several weeks at a time to a height of several feet over the surface of the 

 ground ; in the last case the pod though well formed becomes black 

 and drops off with the seed rotten. 



" You will excuse me for entering on these matters, as you are 

 doubtless conversant with same, bat I merely indicate them to you to 

 •xplain our local cultivation which perhap? has not come directly under 

 your observation." 







SOME CONSTITUENTS OF THE LEAVES OF REUS METO- 

 PIUM, AND HAEMATOXYLON OAMPEA(UiIANUM. 



By A. G. Ferkin, F.R.S.E., of the Glothworker's Research Laboratory, 

 Yorkshire Oollege, Leeds. 



Rhus Metopium, Linn.* 



A re-investigation of the colouring principle present in the leaves 

 of the Rhus Cotinus and Rhus Coriaria (Journal Chem. Soc. 1896, 1299 

 and 1898, 1016) has shown that this is not quercetin as stated by Lowe 

 (Zeit. anal. chem. 1874, 12,127) but myricetin. Quercetin however is 

 found in the leaves of the Rhus rhodanthema ** (New South Wales) and 

 an interesting point with regard to both this plant {Journal Chem. Soc. 

 1897, 11P4) and the R. Cotinus, is that their stems contain a distinct 

 colouring matter fisetin. Research has indicated that quercetin C15 Hio 

 O7 and myricetin ( >i5 Hio Og are respectively hydroxy-and dihydroxy- 

 derivatives of fisetin O15 Hio 0^ and it thus follows that the leaves of 

 these plants contain the colouring matter of the stem in a more oxidised 

 form. In some cases a relationship can be traced between the tannin 

 and colouring matter which co-exist in the plant by means of their 

 respective decomposition products but as in certain instances exceptions 

 occur, no rule can be laid down on this point. It is interesting to note 

 however that myricetin and gallo-tannin both derivatives of pyrogallol 

 are frequently found together, and that the same is the case with quer- 

 cetin which i^ a catechol compound, and the catechol tannins. In 



* [Metopium Linnaei, Engl,] 



•* [Rhodosphaera rhodanthema, Engl,] 



