ALTERATIVES. 115 



Take of Digitalis, 5j ; 

 Nitre, 5ij ; 

 Venice Turpentine, sufficient to form a ball. 



These balls may be given once a-day : in fact, the diuretic 

 does not affect the action of the sedative, for the latter most 

 demand our vigilance. 



The Mode of Operation. — The way in which diuretics 

 remove the consequences of inflammation, is by abstracting 

 from the circulating blood its aqueous part, thereby creating 

 a demand for more ; this acts as a stimulus to the ab- 

 sorbents to take redundant fluids wherever they are to be 

 found in the body. A horse is brought to us for swelled 

 legs. We prescribe a diuretic ball, and direct that it should 

 be walked out twice a-day. In the course of a day or two 

 the legs become fine again. The groom reports the animal 

 has staled more than ordinarily ; by which augmentation of 

 the urine the absorbents have been roused to activity, and 

 have removed the serous effusion in the legs. The presence 

 of aqueous matter in the blood may of itself stimulate the 

 kidneys : this happens when a horse drinks more than 

 ordinarily ; hence water is said to be a diuretic. The same 

 thing takes place when the absorbents, from any cause, are 

 roused to inordinate operation ; hence such medicines as 

 stimulate the absorbent system are said to be diuretics ; in 

 which class we therefore occasionally reckon mercury. 



ALTERATIVES. 



Alterative^ though a term in frequent use, permits con- 

 siderable latitude of construction. An alterative is a remedy 

 that works some beneficial alteration in the system without 

 occasioning any sensible evacuation. A specific is an in- 

 fallible remedy for some particular disease. An alterative 

 may be used where no determinate disease exists, but yet 

 where the system is labouring under some derangement. 

 Whatever the cause of that derangement may be, the altera- 

 tive is supposed gradually to remove it, and to do so with- 

 out creating any disturbance in the body; for, should the 



