SECTION V. 



4 



CHEMICAL ANALYSIS. 



COFFEE has been analysed by several chemists, and though 

 the results obtained differ in some slight degree, yet it seems 

 pretty clear that the principal constituents to which its 

 hygienic and medicinal properties are due are caffeine, a 

 peculiar volatile oil generated in the roasting, and a kind of 

 tannic acid. 



The alkaloid caffeine, or theine, is found in one or two 

 other plants besides tea and coffee. It occurs in the seeds 

 of Paullinia sorlilis, a native of Brazil, and in the leaves of 

 several species of holly, natives of South America, which 

 furnish the Paraguay tea, or Terba mate, so large an article 

 of consumption in several of the South American republics. 

 The leaves and young shoots, dried, parched, and pulve- 

 rised, are used for a hot infusion. A kind of cake, called 

 Gruarana bread, is made from the seeds of the Paullinia , 

 which is highly esteemed in Brazil and other countries when 

 infused, like chocolate, for its nutritive and febrifuge pro- 

 perties, and is sold generally as a necessary for travellers, and 

 as a cure for many diseases. 



The nutritive and medicinal virtues of all these plants must 

 certainly be attributed in a great degree to the presence of 

 this chemical principle, and to the tannic acid which they 

 also contain. 



The use of coffee as a beverage has been examined in a 

 chemical and physiological point of view by Professor 

 Lehmann. The general results of his investigations are : 



