156 MR. C. SCHOHLEMMER ON THE OCCURRENCE OF 



Cacao, which also belongs to the Sterculacese, can be 

 easily transformed into caffeine. 



In collecting this information I consulted, amongst 

 other works, l The Treasury of Botany/ edited by Lindlcy 

 and Moore, where I found the statement that the custom 

 of drinking coffee originated with the Abyssinians, who 

 cultivated the plant from time immemorial. In Arabia it 

 was not introduced until the early part of the fifteenth 

 century; before this time the beverage made from the 

 leaves of the kat (Catha edulis) was generally used, and 

 is still in use, possessing properties resembling those of 

 strong green tea, only more pleasing and agreeable. The 

 leaves are also chewed, and are said to have the effect of 

 producing great hilarity of spirits, and such an agreeable 

 state of wakefulness that the Arabs, who chew them, are 

 able to stand sentry all night long without feeling drowsy. 



As the properties of kat resemble so much those of tea, 

 it appeared to me highly probable that it contains 

 caffeine. My friend Mr. H. Marshall Ward was kind 

 enough to apply to Professor W. T. Thiselton Dyer, F.R.S., 

 w r ho supplied me in the beginning of December with 

 fresh leaves of a plant growing in the temperate house 

 at Kew Gardens. He also sent me a sample from the 

 museum. He says, "The material in our museum is not 

 very satisfactory; but I enclose a portion of an authentic 

 sample. The leaves are different in form from those of 

 the living plant ; but I have ascertained that in this 

 respect they are variable." 



I first examined the fresh leaves ; not a trace of caffeine 

 could be found, while its presence can be easily shown in 

 three or four tea-leaves. The only crystalline compound 

 which I could extract from Catha is a kind of sugar, 

 apparently mannite. The quantity was, however, too small 

 for identifying it. 



