Coffee 



197 



head in the United States is very high, about 11 to 121b. per annum, which, is equalled or 

 exceeded only in Norway, Sweden, and Holland. ' We "take the lowest position, the average 

 consumption per head in the United Kingdom being less than. 1 lb. ^per annum. Similarly 

 in Canada, each individual uses on the average less than 1 lb. of coffee yearly, solhatthe 

 relatively enormous consumption in the United States is rendered the more striking. 



Germany follows the United States, using considerably less than one-half the total 

 of the latter country, but then the individual consumption in Germany is only between 6 and 

 71b. per annum. France, Austria-Hungary, and Holland are next in order of consumption. 

 Sweden, Belgium, and the United Kingdom form another little group, each taking about 

 half the amount used in Holland or Austria-Hungary. In Sweden and Belgium there is' a 

 high individual consumption, whereas in the United Kingdom, as already noted, it is very low. 



THE ACTIVE PRINCIPLE OF COFFEE 



The stimulating and refreshing action of coffee is mainly due to the presence of caffeine 

 and a volatile oil. Caffeine belongs to the group Of substances known as alkaloids, which as 

 a class have usually a bitter taste and are only slightly soluble in water. Amongst other 

 well-known alkaloids are cocaine, the active principle obtained from coca leaves ; morphine, 

 codeine, and narcotine, the essential constituents of opium; quinine and cinclionine, to which 

 the bark of cinchona owes 

 its properties ; theobro- 

 mine contained in cacao. 

 Theine, the alkaloid of 

 tea, is practically identi- 

 cal with caffeine, and 

 both are very similar to 

 theobromine. Paraguay 

 tea or Mate and kola nuts 

 contain caffeine. 



The quantity of caf- 

 feine present varies 

 greatly in different 

 species of coffee. It is 

 never very large in 

 amount, slightly under 

 2*0 per cent, of the dry 

 seeds being the highest 

 recorded. Analyses of 

 Arabian coffee show a 

 range of between 0*7 

 and 1*6 per cent., whilst 

 Liberian coffee varies 

 from about l'O to 15 

 per cent. The wild Sierra 

 Leone coffee (C 'off 'easteno- 

 phylla) contains about 

 1*5 per cent. Four spe- 

 cies of coffee, natives of 

 Madagascar or of the 

 neighbouring islands, do From p koto by pennon 0/ 

 not contain any caffeine. Jamaica coffee tree 



'"Son Kingston, Jamaica 



