178 COFFEE. 



much legumin, and a little gum. It yields twenty to twenty-fiv 

 per cent, to water. It is likely that these food substances, as mod: 

 fied by roasting, disagree with the digestion of many personi 

 This may be why substitution of tea-drinking sometimes give 

 relief to those suffering from drinking coffee. 



It is to be hoped that more of our chemists will give attentio: 

 to this matter in the interests of economic science. As is we] 

 known, the quality of coffee improves by long keeping, and 

 chemical analysis of coffee beans of different ages might indicat 

 the cause of the improvement, and possibly its production by ai 

 tificial means. 



Prof. Johnston states that, weight for weight, tea yield 

 about twice as much theine as coffee does to the water in whicl 

 it is infused, " but as we generally use a greater weight of coffei 

 than we do of tea in preparing our beverages, a cup of coffee o; 

 ordinary strength will probably contain as much theine as a cuj 

 of ordinary English tea. One cup of strong French coffee wil 

 contain 'twice as much caffeine as a cup of weak French tea." 



The two subjoined analyses serve to show the comparativ( 

 composition of the roasted berry and the tea-leaf. 



Tea. Coffee. 



(Mulder.) (Payen.) 



Water 5.0 12.0 



Gum and sugar 21.0 15.5 



Gluten 25.0 13.0 



Theine 0.5 0.75 



Fat and volatile oil 4.0 13.0 



Tannic acid. : 15.0 5.0 



Woody fibre 24.0 34.0 



Ash 5.5 6.71 



The above analyses must not be relied upon for any othe: 

 purpose than that of a general comparison. It will be seen tha 

 the theine is much understated in the tea. 



Swallowed with the grounds, as is done in Turkey, coffei 

 undoubtedly affords much nourishment. Mr. Payen states tha 

 it contains more than twice the nutriment of soup, and threi 

 times as much as tea. In the beverage, however, prepared as i 



