274 Considerations on the Bitterness of Vegetables, 



The author remarks (page 51,) that the monocotyledones arc 

 less abundantly provided with bitter juices than the dicotyledones, 

 but that the juice extracted from the leaves of different species 

 of aloes makes a remarkable exception to this general observation. 

 After relating the facts knov^^n upon the chemical nature of the juice 

 of aloes, he analyses its properties as follows. 



" Aloes is one of the most eminent substances employed in medi- 

 cine. It exercises its action upon the organs of digestion. In very 

 minute doses, (two or three grains,) it slightly excites the stomach, 

 and facilitates digestion ; it is in this way that the health grains of 

 Dr. Frank, and the antecibum pills, etc., act. In a stronger dose 

 (eight grains,) its action, according to most authors, extends to the 

 intestines, and is exerted especially upon the lower tract of the di- 

 gestive canal. It there increases the afflux of blood, the mucous 

 secretion, and occasions the expulsion of matter, amassed in the 

 large intestine. Finally, aloes when given in a stronger dose, and 

 its use continued, gives rise to colics ; the rectum becomes the seat 

 of a genuine flux, the hsemorrhoidal vessels are distended, hsemor- 

 rhoidal tumors become painful, and frequently gives place to an 

 abundant oozing of blood. We have profited by the stimulating ac- 

 tion, especially, which aloes exercises upon the rectum, and the de- 

 termination which it produces to this part, in order to cure certain 

 megrims, caused by obstinate constipations. In producing a useful di- 

 rection towards the rectum, it has often diminished a sanguinary 

 congestion, induced towards the head." 



^' Such was the general opinion of physicians upon the modus 

 operandi of aloes ; but we have to oppose them with more positive 

 and totally contradictory experiments." 



In a Memoir upon the employment of the aqueous extracts of 

 aloes, and its manner of acting, published by Baron de Wedekind, 

 (Isis 1825 ; ilth No. p. 1227,) this physician promulgates the opin- 

 ion, after multiplied experiments, that the purgative effects of aloes 

 are not dependent upon, as is the case with other cathartics, an aug- 

 mentation of the intestinal secretion, and an immediate stimulation of 

 the contractile fibres of the intestines, but that this substance is first 

 absorbed, carried into the circulation, then secreted in great part by 

 the liver, whose activity it increases, and is finally ejected from the 

 body in consequence of a purgative effect which is only secondary. 

 In fact, the purgative action of aloes is only manifested several 

 liours after its injection, in whatever dose it may have been taken. 



