CHEMICAL ANALYSIS OF COFFEE. 181 



Belgian coal-miners live and work efficiently upon a ration of 

 solid food much less than that of the French miners, and yet 

 perform more labor than the latter. The only difference in the 

 quality of their food consists in the Belgians receiving a ra- 

 tion of coffee, and to this is attributed their superior endurance. 

 . . . . It may seem at first sight irrational that a substance 

 which restricts tissue-waste should be used for the very purpose 

 of quickening certain functions, and especially those of the brain. 



" It restricts tissue-waste, and yet it is used to quicken certain 

 functions, especially those of the brain. The mental exhilara- 

 tion, physical activity, and wakefulness it causes explains the 

 fondness for it which has been shown by so many men of 

 science, poets, scholars, and others devoted to thinking. It has, 

 indeed, been called ' the intellectual beverage.' 



"But all of these occupations involve increased functional 

 activity, and therefore increased waste of tissue in the brain and 

 spinal marrow, the very action which coffee is said to restrain. To 

 reconcile these apparent incongruities, it has been maintained that 

 coffee does not act primarily as a cerebral stimulant, but only 

 secondarily by removing the vascular plenitude occasioned by 

 prolonged study, by a full meal, and especially by alcohol, opium, 

 or other agents which directly tend to load the brain with blood ; 

 that, if taken on an empty stomach, it does not qiiicken the func- 

 tions of the brain, but, on the contrary, renders it dull and inapt 

 for steady thought, creates general debility and nervousness, and 

 frequently causes Jiemicrania. 



" During digestion, however, the case is different, particularly 

 if a full and stimulating meal has been taken ; the mind grows 

 dull and sluggish, a tendency to sleep arises, and everything indi- 

 cates an increased amount of blood in the brain. In like manner 

 prolonged mental labor produces cerebral plenitude and drowsi- 

 ness. It is this condition, apparently, which coffee corrects by 

 contracting the blood-vessels and relieving the brain of its oppres- 

 sive load of blood. The habit of taking coffee at breakfast and 

 after "dinner is explained by the stimulant action (whether direct 

 or indirect) which it exerts not only upon the nervous system 

 generally, but especially upon the stomach and bowels. There 

 can be no doubt that it quickens gastric digestion and relieves the 



