850 JOURNAL OF FORESTRY 



It is, therefore, essential to examine the nature of this substance with 

 considerable care. 



It is readily soluble in water, alcohol, and wood spirit, fairly soluble 

 in acetic ether, and can be extracted with glycerin. It is also soluble 

 in ether when wet; but insoluble in benzene, benzol, petroleum ether, 

 carbon bisulphide, etc. The red color produced upon the addition of 

 alkali to the aqueous extract of the heartwood is turned to yellow 

 with acid, while it can be changed again to red or purplish red with 

 alkali, e. g., the color reaction is more or less reversible with alkali 

 and acid. Chemical investigations of this substance had already been 

 carried out by pharmacologists, interested in the close relation tO' the 

 wood of "Sugi" to the Japanese "Sake" industry, where the container 

 is made of staves of this wood. But, since it is amorphous, no definite 

 chemical formula can be given to this substance. K. Keimatsu ^ sup- 

 posed it might be one of the polyhydric phenols. H. Kimura ^^ states 

 that it might be something like orthoquinone, an oxidation product of 

 catechol (which is derived from glucovanillin, which is itself derived 

 from coniferin). As the definite chemical composition of this sub- 

 stance is unknown, in this article it will be termed "particular sub- 

 stane," or "chromogen" of the phenomenon for the sake of con- 

 venience and simplicity. Catechol is a well-known substance existing 

 in woods." Puran Singh ^^ reports the diminution of the catechin 

 content in the wood of Acacia catechii during storage as well as while 

 it is standing. 



The authors' experiments with ferric chloride on the fresh sapwood 

 of "Sugi" compared with those of pine, spruce, fir, maple, basswood, 

 Cottonwood, etc., suggested the abundant existence of catechol therein, 

 showing a marked green tint. Methyl alcoholic extract of the saw- 

 dust of the same material gave a green color with ferric chloride, which 

 turned to purplish red on the application of sodium bicarbonate. These 



'Keimatsu, Katsuzaemon. On the Ingredients of the Wood of "Sugi." Jour- 

 nal of the Japanese Pharmacology, No. 277, 1915 (in Japanese). 



'"Kimura. Hikoemon. On the Ingredients of the Japanese "Sake." Journal 

 of the Japanese Pharmacology, No. 284, 1905 (in Japanese). 



"Tunmann, O. Phlanzenmikrochemie, Berlin, 19i:i 



'•■ Puran Singh. A Short Preliminary Note on the Suitability of the Dead 

 Wood of Acacia catechu for Katha-Making. Indian Forester, vol. .38, April, 

 1912. pp. 154-156. 



Puran Singh. Note on the Effect of Age on the Catechin Content of the Wood 

 of Acacia catechu. Indian Forester, vol. 41, Dec. 1915. pp. 482-485. 



