THE TECHNOLOGIST. [August 1, 1864. 



2S 



CHEMICAL ANALYSIS OF COFFEE. 



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 sorhilis, a 

 native of Brazil, and in the leaves of several species of holly, natives of 

 South America, which furnish the Paraguay tea, or Yerba mate, so large 

 an article, of consumption in several of the South American republics. 

 The leaves and young shoots, dried, parched, and pulverised, are used 

 for a hot infusion. A kind of cake, called Guarana bread, is made from 

 the seeds of the Paullinia, which is highly esteemed in Brazil and otber 

 countries when infused, like chocolate, for its nutritive and febrifuge 

 properties, 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 cer- 

 tainly 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 considered in a chemical 

 and physiological point of view by Professor Lehmann. The general 

 results of his investigations are : 



1. That a decoction of coffee exercises two principal actions upon the 

 organism, which are very diverse in character, viz., increasing the ac- 

 tivity of the vascular and nervous system, while at the same time it 

 retards the metamorphosis of plastic constituents. 



2. That the influence of coffee upon the vascular and nervous system, 

 its reinvigorating action, and the production of a general sense of cheer- 

 fulness and animation, is attributable solely to the mutual modification 

 of the specific action of the empyreumatic oil and the caffeine contained 

 in it. 



3. That the retardation of the assimilative process brought about by 

 the use of coffee is owing chiefly to the empyreumatic oil, and is caused 

 by caffeine when taken only in large cpiantities. 



4. That increased action of the heart, trembling, headache, &c, are 

 effects of the caffeine. 



5. That the increased activity of the kidneys, relaxation of the 

 bowels, and an increased vigour of mental faculties, passing into conges- 

 tion, restlessness, and inability to sleep, are effects of the empyreumatic 

 oil. 



Professor Lehmann considers it, therefore, necessary to regard the 

 action of coffee, and, in a less degree, that of tea, cocoa, alcohol, &c, 

 upon the organism, as constituting an exception to the general law, that 



