116 TREATMENT OF INFLAMMATION. 



remedy purge the animal, or sensibly increase the flow of its 

 secretions, the medicine would no longer be alterative in 

 its action. 



Aloes, Antimony, Nitre, and Mercury, are the agents 

 commonly given as alteratives. Aloes is our commonpurge-, 

 antimony is a diajjhoretic ; nitre is a diuretic ; and mercury 

 increases the flow of bile and saliva : hence we discover that 

 alteratives form no distinct class of medicines, but are de- 

 rived from most, if not all, of the other classes. This shows 

 that the alterative eff'ect is brought about in various ways ; 

 for, notwithstanding the agents to be alteratives must be given 

 in diminished doses, and though called by one name, they 

 cannot in efl'ect all be similar : thus a purgative operates, in 

 however small a quantity, diff"erently from a diuretic ; while, 

 so extensive is the action of mercury, that, while it diff*ers 

 from all other alteratives, it, in a measure, resembles them, 

 from combining their properties, to a greater or less degree, 

 within itself. 



Aloes, then, is exhibited with one of three objects in 



view — either as a purge, in doses from four to eight drachms; 



oi" as a laxative, in doses of two and three drachms ; and as 



an alterative, in doses of half a drachm or a drachm; in 



fact, we give aloes in small doses either as a nauseant or an 



alterative; the first being its immediate efi^ect on the 



stomach; the second, the efiect it has on the constitution. 



To explain how aloes, or any other alterative, produces all 



the good ascribed to it, is not within our power : we may, 



however, approach nearer to this than in the case of other 



alteratives ; for we know that aloes when administered and 



continued in small doses, improves the digestion; a change 



within the stomach must, in all cases, be followed by a 



general amendment of the health. The gentle stimulant of 



small doses within the bowels increases the peristaltic action, 



and produces a slow drain of what Mr. Abernethy regards as 



'^morbid secretions." Aloes also augments the flow of 



bile ; and in small doses aff'ects the kidneys, producing more 



urine than ordinary. Still, all these efi'ects are produced, 



in a manner, imperceptible to the observer ; and therefore 



