MATERIA MEDICA. 



they may be employed, to diminish the 

 quantity of circulating fluids, where it is 

 greater than the state of the system at 

 the time can admit of; to restore dimi- 

 nished lymphatic absorption, and to dis- 

 charge morbid accumulations of serum. 

 These indications may be illustrated and 

 confirmed, from practical observations 

 concerning the effects of diaphoretic me- 

 dicines in fever, dysentery, rheumatism, 

 dropsy, and herpes. 



The cautions to be observed in the 

 employment of diaphoretic medicines, 

 as derived from their nature, chiefly 

 respect the determination they produce 

 to the surface; the acceleration of the 

 motion of the blood, which many of them 

 occasion ; the debility which, in conse- 

 quence of the discharge, is produced in 

 the system ; and the effects sometimes 

 produced on the vessels of the surface 

 themselves, by the free passage of the 

 blood through them. The conditions of 

 the system, which chiefly require atten- 

 tion in their employment, are, the period 

 of infancy; lax and debilitated habits; 

 constitutions liable to costiveness. 



4. Of Diuretics. 



These are medicines which, from be- 

 ing taken internally, augment the flow 

 of urine from the kidnies, by stimulating 

 its secretion from the mass of circulating 

 fluids. The changes induced in the sys- 

 tem from these direct effects, are, a 

 change in the balance of circulation ; a 

 diminution of the quantity of circulating 

 fluids; but more especially of the serosity 

 and of the saline parts of the blood ; an in- 

 crease of absorption by the lymphatic ves- 

 sels ; a diminution of the quantity of mat- 

 ter discharged by perspiration ; and an 

 uncommon flow of fluid through the 

 urinary passages. 



Diuretics may be divided into such as 

 are stimulant, of which we have instances 

 in squills, broom, colchicum, cantha- 

 rides ; refrigerant, as sorrel, berberry, 

 vinegar, cream of tartar ; and diluent, as 

 water, whey, and acidulated waters. 

 Their use and indication may be ascer- 

 tained from the following effects: 1. Their 

 producing evacuation ; whence they may 

 be employed to remove superabundant 

 serosity from the blood ; to evacuate 

 morbid accumulations of serum ; to re- 

 move morbid acrimony from the blood ; 

 to diminish the quantity of circulating 

 fluids, when too great for the state of the 

 system at the time. 2. From their alter- 

 ing the mode of circulation; whence they 



may be employed, to restore the natural 

 secretion of urine, when morbidly dimi- 

 nished; to diminish other secretions, 

 when morbidly augmented. 3. From 

 their augmenting the flow of liquid 

 through the urinary passages ; whence 

 they may be employed, to remove ob- 

 structions in these passages, and to 

 wash out acrimony from them. These 

 indications may be illustrated by an at- 

 tention to the effects of this class of 

 medicines, as employed in ascites, icto- 

 rus, and nephritis. 



5. Of Cathartics. 



These are medicines which, taken in- 

 ternally, increase the number of stools, 

 by stimulating the alimentary canal, in- 

 creasing the peristaltic motion of the in- 

 testines, and promoting the secretion 

 of the fluids which constitute alvine 

 evacuations. They may be subdivided 

 into the following tribes : stimulant, as 

 jalap, aloes, bitter-apple ; refrigerant, 

 as Glauber's salts, sal polychrest, cream 

 of tartar ; astringent, as rhubarb, rose- 

 leaves ; and emollient, as manna, mal- 

 lows, castor oil. 



The changes induced in the system 

 from the primary effects of cathartics, 

 are, the evacuation of the contents of 

 the intestines; a diminution of the quan- 

 tity of circulating fluids, and, in a parti- 

 cular manner^ of the serosity ; a change 

 in the balance of circulation; a diminu- 

 tion of perspiration ; higher excitement 

 of the nervous energy in the system in 

 general, but more especially in the intes- 

 tinal canal. 



The indications which cathartic medi- 

 cines are capable of fulfilling, may be de- 

 rived from the three following sources : 

 1. From their producing evacuation , 

 whence they may be employed, to obvi- 

 ate morbid retention of the contents of 

 the intestines ; to diminish the quantity 

 of circulating fluids when too great for 

 the then state of the system ; to evacu- 

 ate morbid accumulations of serum. 2 

 From their altering the balance of circu- 

 lation ; whence they may be employed to 

 promote free circulation through the in- 

 testines, in those cases where it is mor- 

 bidly impeded ; and to diminish the im- 

 petus of the blood against parts morbidly 

 affected. 3. From the affection of the 

 nervous system which they occasion ; 

 whence they may be employed to re- 

 move torpor in the muscular fibres of the 

 intestines ; and to restrain inordinate mo- 

 tions in their muscular fibres. These in- 



