MATERIA MEDICA. 
10. Of Refrigerants. 
These are medicines which, as their name 
implies, are supposed to diminish tlie heat 
of the living body, not by the application ot 
an actual cold, but by a power peculiar to 
themselves. 
They may be considered under the two 
divisions of acids or acetous truits, as tama- 
rinds, berberries, lemons, wood-sorrel ; and 
neutral salts, as nitre, Glauber’s salt, sal 
po'ychrest They may hence be usefully 
employed; 1. In cases of febrile heat, or ot 
general plethora, and an useful 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 seda- 
tives more properly so called of Class XV. 
of this system. In the employment of 
these medicines attention should be paid to 
their power of diminishing action, and 
either generally checking the secretions of 
the system, or augmenting some by a dimi- 
nution of others. Hence they are contra- 
indicated in cases of chlorosis, leucophleg- 
matic habits, an l predispositions to dropsi- 
cal affections. We enlarge the less, how- 
ever, upon this subject, because the indica- 
tions and contra-indications are closely 
connected, as we have just observed, with 
the articles and the remarks offered upon 
Class XV. of which, in various systems of 
therapeutics, they merely constitute a sepa- 
rate division. 
11. Of Astrh^genis. 
These are medicines which possess a 
power of condensing the animal fibre with- 
out the aid of mechanical action. In gene- 
ral they are found to excite a peculiar sen- 
sation referred to the part to which they 
are applied ; if to the organs of taste, a 
sense of dryness. They produce a remark- 
able corrugation in the parts ort which they 
more immediately act. They occasion, in 
some degree, a similar affection through the 
rest of the system. Some individuals be- 
longing to this class produce an evident 
condensation in dead animal fibres, The 
changes induced in the system from the 
primary effects of astringents, are: an in- 
crease of the power of cohesion in various 
parts of the annual body; an increase of 
what may be ter med the tonic power in the 
system : a diminution of the capacity of 
containing vessels in the system ; a diminu- 
tion of irritability, and perhaps, in some de- 
gree, of sensibihty. 
Astringents may be divided into styptic, 
of which we have examples in most metal- 
lic oxids, as well as in aluminous earths : 
corrugant, as rose-leaves, galls, oak-bark ; 
induraut, as alcohol and acids ; and tonic, 
as exercise, cold, and friction. 
The indications of cure which the class 
of astringent medicines are capable of ful- 
filling may be deduced from the following 
sources. 1. From the alteration they pro- 
duce on the state of the moving solids: 
whence they may be employed, to obviate 
original delicacy ; to restore natural com- 
pactness to parts morbidly, relaxed ; to re- 
store diminished tonic power; to diminish 
mobility when morbidly increased. 2. From 
the alteration they produce on the state of 
the containing vessels : whence they may 
be employed, to diminish secretions moi-- 
bidly augmented ; to increase the power of 
retaining excieraentitious matters when 
morbidly diminished ; to produce a con- 
striction on the orifices of ruptured ves- 
sel's. 
These indications may be illustrated and 
confirmed from practical observations con- 
cerning the effects of astringents in cases of 
hysteria, epilepsy, hmmorrhage, and diarr- 
bcea. 
Tire cautions to be observed in the em- 
ployment of astringents, as derived from 
their nature, chiefly respect the stimulant 
and caustic powers possessed by many indi- 
viduals belonging to the class : the effects 
of an alteration produced in the solids, if 
carried beyond the natural state ; and, in a 
particular manner, their influence as dimi- 
nishing secretions; and as increasing the 
power of the system for the retention of 
excrementitious matters. The conditions of 
the system which chiefly require attention 
in their employment, are, old age, melan- 
cholic habits, and particular morbid affec- 
tions of the stomach. The circumstances 
chiefly to be attended to in the regimen ne- 
cessary, respect, the avoiding a relaxing 
diet ; and the keeping the patient in a cool 
temperature and dry air. 
Astringents are chiefly contra-indicated 
by the presence of tbe following morbid 
states,; a high degree of rigidity in the sys- 
tem in general ; remarkable insensibility in 
the moving fibres ; and particular diminu- 
tion of the excretions from the body. 
12. Of Tonics, 
The medicines thus denominated are 
those which increase the tone of the muscu- 
lar fibre, are supposed to brace the .system 
when constitutionally relaxed, and give it 
