268 MEDICINAL EFFECTS. 



by contracting the blood-vessels and thereby relieving 

 the brain of its oppressive load of blood. The habit of 

 using coffee at breakfast and after dinner is thus explained 

 by the stimulant action which it exerts, not only upon 

 the nervous system generally, but more especially on the 

 stomach and bowels, there being no doubt that it quickens 

 gastric digestion and relieves the sense of plenitude in 

 the stomach, stimulating the secretion of bile and aug- 

 menting the peristaltic action of the intestine, and there- 

 by promoting defacation. While it is quite as certain 

 that, used to excess, it paralyzes the digestive function in 

 all its stages and leads to further disorders, of which the 

 chief are constipation, hemorrhoids and congestion of 

 the liver, but whether these effects are to be ascribed to 

 a power in coffee to produce contraction of the capillary 

 blood-vessels or not is uncertain, but their reality is 

 beyond dispute. 



With regard to the injurious effects charged to the 

 abuse of coffee by some authorities, it may be said that 

 the consequences of an abuse of tea were declared to be 

 similar to that of coffee long before chemistry had 

 demonstrated the identity of theine with caffeine^ when 

 among their evil effects were enumerated acidity, heartburn, 

 indigestion, tremors, wakefulness, irritability of disposition 

 and depression of spirits. Most of these ill-effects 

 are more likely to follow the abuse of tea than coffee, if 

 at all, and the spinal symptoms, such as painful muscular 

 tension, cramp and persistent wakefulness, are also more 

 apt to be produced by tea. In experiments made with a 

 number of selected healthy persons, the operation of 

 caffeine has been found to vary exceedingly, some being 

 scarcely affected at all, while others by the same dose 

 suffered from a full, frequent or irregular pulse, headache, 

 trembling limbs, palpitation of the heart, flashes before 



