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1. That a decoction of coffee exercises two principal 

 actions upon the organism, which are very diverse in cha- 

 racter, viz. increasing the activity of the vascular aod 

 nervous system, while at the same time it retards the meta- 

 morphosis 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 cheerfulness and animation, is attrir 

 butable 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 empyreu- 

 matic oil, and is caused by caffeine only when taken in large 

 quantities. 



4. That increased action of the heart, trembling, head- 

 ache, &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 congestion, 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 ex- 

 ception to the general law, that increased bodily and mental 

 activity involves increased consumption of plastic material. 



Caffeine, on careful analysis, has been found to contain in 

 100 parts, 49-80 of carbon, 5'08 of hydrogen, 28'83 of 

 nitrogen, and 16'29 of oxygen. It is inodorous, but has a 

 slightly bitter taste. The proportion in which this principle 

 is found to be present in coffee varies between jib. and 

 If Ibs. in 100 Ibs. of berries. 



The peculiar essential oil which is generated in coffee in 

 the process of roasting, by the action of heat upon some yet 

 unascertained principle contained in the berry, is also very 



