MATERIA MEDICA. 



leucophlegrnatic habits, and predispo- 

 sitions to dropsical affections. We en- 

 large the less, however, upon this sub- 

 ject, because the indications and contra- 

 indications are closely connected, as 

 we have just observed, with the arti- 

 cles and the remarks offered upon Class 

 XV. of which, in various systems of 

 therapeutics, they merely constitute a 

 separate division. 



11. Of Astringents. 



These are medicines which possess a 

 power of condensing the animal fibre 

 without the aid of mechanical action. In 

 general they are found to excite a pecu- 

 liar sensation referred to the part to 

 which they are applied ; if to the organs 

 of taste, a sense of dryness. They pro- 

 duce a remarkable corrugation in the 

 parts on which they more immediately 

 act. They occasion, in some degree, a 

 similar affection through the rest of the 

 system. Some individuals belonging to 

 this class produce an evident condensa- 

 tion in dead animal fibres. The changes 

 induced in the system, from the primary 

 effects of astringents, are, an increase 

 of the power of cohesion in various parts 

 of the animal body ; an increase of what 

 may be termed the tonic power in the 

 system ; a diminution of the capacity of 

 containing vessels in the system ; a dimi- 

 nution of irritability, and perhaps, in some 

 degree, of sensibility. 



Astringents may be divided into styp- 

 tic, of which we have examples in 

 most metallic oxides, as well as in alumi- 

 nous earths ; corrugant, as rose-leaves, 

 galls, oak-bark ; indurant, as alcohol and 

 ucids ; and tonic, as exercise, cold, and 

 friction. 



The indications of cure, which the 

 class of astringent medicines are capable 

 of fulfilling, may be deduced from the 

 following sources. 1. From the altera- 

 tion they produce on the state of the 

 moving solids: whence they may be em- 

 ployed, to obviate original delicacy; to 

 restore natural compactness to parts 

 morbidly relaxed ; to restore diminished 

 tonic power; to diminish mobility when 

 morbidly increased. 2. From the altera- 

 tion they produce on the state of the 

 containing vessels : whence they may be 

 employed, to diminish secretions mor- 

 bidly augmented ; to increase the power 

 of retaining excrementitious matters 

 when morbidly diminished , to produce 

 a constriction on the orifices of ruptured 

 vessels. 



These indications may be illustrated 

 and confirmed from practical observations 

 concerning the effects of astringents in 

 cases of histeria, epilepsy, haemorrhage, 

 and diarrhoea. 



The cautions to be observed in the 

 employment of astringents, as derived 

 from their nature, chiefly respect the 

 stimulant and caustic powers possessed 

 by many individuals belonging to the 

 class : the effects of an alteration pro- 

 duced in the solids, if carried beyond the 

 natural state ; and, in a particular man- 

 ner, their influence as diminishing secre- 

 tions ; and as increasing the power of the 

 system for the retention of excrementi- 

 tious matters. The conditions of the sys- 

 tem whicli chiefly require attention in 

 their employment, are, old age, me- 

 lancholic habits, and particular mor- 

 bid affections of the stomach. The cir- 

 cumstances chiefly to be attended to 

 in the regimen necessary, respect the 

 avoiding a relaxing diet ; and the keep- 

 ing the patient in a cool temperature and 

 dry air. 



Astringents are chiefly contra-indi- 

 cated by the presence of the following 

 morbid states; a high degree of rigidity 

 in the system in general ; remarkable 

 insensibility in the moving fibres ; and 

 particular diminution of the excretions 

 from the body. 



12. Of Tonics. 



The medicines thus denominated are 

 those which increase the tone of the 

 muscxilar fibre, are supposed to brace 

 the system when constitutionally relaxed, 

 and give it vigour when debilitated by 

 immediate disease. They may be divid- 

 ed into stimulants, as various prepara- 

 tions of mercury, iron, zinc, and other 

 metals ; and astringents, as chamomile- 

 flowers, myrrh, Peruvian, and other 

 barks, and gentian. It is hence obvious, 

 that this class of medicines has a near re- 

 lation to those noticed in the class that 

 immediately precedes, and immediately 

 follows it. On which account we shall 

 dismiss it with a single additional obser- 

 vation or two. The changes induced in 

 the system by the use of tonics are, in- 

 crease of muscular pow r er, greater mode- 

 ration, and a firmer stroke of the pulse, 

 increased desire for food, and an aug- 

 mented vivacity of the animal spirits. 

 Hence their use is clearly indicated in all 

 cases in which there is a deficiency of 

 these natural powers or desires. They 

 are therefore contra-indicated by the ex- 



