They may be regarded as humectant, of which we have examples in warm wa ter, warm vapour, and warm baths ; laxative, as marshmallows, mallows, white lily root ; lubricative, as bland oils, suet, hog's lard ; atonic, as opium, foot-bath.
The curative indications of emollients may be collected •hence 1. From their producing a change in the state of the moving solids. Hence they may he em ployed to restore the natural flexibility to parts morbidly rigid ; to diminish a mor bid increase of tonic power. 2. From their producing a change in the state of the containing vessels. Hence they may be employed, to obviate the eflects of morbid distention ; to remove obstruc tions. These indications may be illus trated and confirmed, from practical ob servations concerning the effects of this class of medicines, as employed in cases of contraction, rigidity, and tumor. The cautions to be observed in the employ ment of emollients, as derived from their nature, chiefly respect their influence as acting on the system in general ; and the effects of a degree of laxity induced in particular parts, hiker than is natural to these. The conditions of the system which chiefly require attention in their employment are, the period of youth ; delicacy of habit ; and debility. The circumstances chiefly to be attended to in the necessary rebimen, respect the temperature and air in which the patient is kept ; and the mode of applying the emollient. The class of emollients are chiefly contra-indicated by the presence of the following morbid states: a high de gree of morbid relaxation in the system in general ; and a peculiar sensibility of the moving fibres.
10. Of Refrigerants.
These are medicines which, as their name implies, are supposed to diminish the heat of the living body, not by the application of an actual cold, but by a power peculiar to themselves.
They may be considered under the two divisions of acids or acetous fruits, as tamarinds, berberries, lemons, wood-sor rel ; and neutral salts, as nitre, Glauber's salt, sal polychrest. They may hence be usefully employed ; 1. In cases of febrile heat, or of general plethora, and an use ful auxiliary to the tribe of refrigerant cathartics. 2. As sedatives, to diminish
undue irritability and action of any of the vascular systems, and are hence usefully conjoined with the sedatives, more pro perly so called, of Class XV. of this sys tem. In the employment of these medi cines attention should be paid to their power of diminishing action, and either' generally checking the secretions of the system, or augmenting some by a diminution of others. Hence they are contra-indicated in cases of chlorosis, leucophlegmatic 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 ; Mention% as alcohol and acids ; and tonic, as exercise, cold, and friction.