282 EXPERIMENT TRIED ON COFFEE. 



base, was not present before the fermentation. 

 The different kinds of tobacco are distinguishable 

 from one another, like wines, by having very dif- 

 ferent odoriferous substances, which are generated 

 along with the nicotine." * 



As connected with this subject, though depend- 

 ent on other causes, it may here be observed that 

 it is remarkable with what ease tea gives out its 

 own odour, and imbibes that of other substances 

 by contact or proximity, especially in a humid 

 state of atmosphere. Even a compound flavour 

 is sometimes formed, which neither resembles its 

 own nor the one it imbibes. It is well known that 

 turmeric, and some other drugs, deprive tea of its 

 agreeable odour, and change it into one resembling 

 that of herbs. This flavour may often have been 

 detected in tea during domestic use. This objec- 

 tionable smell and flavour is perfectly well known 

 to dealers, as well as its cause. 



As, however, much stress is laid on aroma as 

 depending on a volatile oil, which, is known in 

 some cases, and is very generally supposed in 

 others, to be readily driven off by high tempera- 

 ture, I was induced to try, through the assistance 

 of a friend, this experiment on coffee. 



We pounded a few unroasted coffee berries in a 

 mortar, till they were reduced to a fine powder. 

 This was put into a glass tube, and both the tube 



* Liebig's Chemistry of Agriculture, translation, 2d edit, 

 p. 319. 



