298 



U. SUZUKI. LOCALIZATION OF THEINE. 



on theine after the addition of a little hydrochloric or sulphuric 

 acid and on application of this acidulated solution the epidermal 

 cells gave decidedly a much more intensely brown color than 

 the others which remained merely slightly yellowish. The most 

 decisive answer however was reached by the following test. 

 When a section of the leaf was placed in a o.$% theine solution, 

 the cells of the spongy and palisade tissues exhibited a very 

 marked formation of proteosomes. (1) This fact appeared rather 

 strange to me, since the coffeine content of the fresh leaves is 

 certainly more than 0.5% and thus the formation of proteosomes 

 ought to take place in the fresh leaves without any application of 

 coffeine. (2) Since however no proteosomes were observed in the 

 epidermal cells (which are in other plants often very rich in the 

 stored up active albumen) by the action of the 0,5% coffeine 

 solution, there remain no other conclusion than this, that these 

 cells contain no active albumin and at the same time contain all 

 the theine of the leaves. A further test with tannin proved this 

 conclusion to be correct. A section of the leaf was left for two 

 days in a tannin solution of about 3-4% ; hereby a voluminous 

 precipitate consisting of minute globules was produced in the 

 epidermal cells, while the other tissues of the leaves showed only 

 a slight turbidity. To prove that this precipitate consisted of 

 tannate of theine was furnished by the application of highly- 

 diluted ammonia, which dissolved it at once. (:i) This affords an 

 easy way of distinguishing the precipitate from minute proteo- 

 somes, which latter solidify on the absorption of ammonia, and 

 do not dissolve at all in it. 



Hence there can be no longer any doubt that the theine in 

 the tea leaves is localized in the epidermis. 



(i) Compare: IX and X of Chcmische Energie der Lebenden Zellen by O. 

 Loew Munich. 1899. 



C2) This led me at first to the supposition that the theine in the fresh leaves, was 

 present not in the free state but in a loose combination with some other substance. 

 Hence I extracted the green leaves, after crushing them, directly with chloroform, but I 

 obtained about the same quantity of theine for the dry matter as with the tea of com- 

 merce. The theine is therefore contained in the leives in the free state. 



( 3 ) It is well known that some authors made the great mistake of confounding 

 tannate of theine with true proteosomes. 



