flavour.” The phenomenon of vomiting, as 
to its remote cause, is of difficult explana- 
tion. It cannot be owing simply to debili- 
tated, and consequently inverted action of the 
stomach from previous excitement, as a 
greater quantity of stimulus may be thrown 
into this organ without being succeeded by 
an inversion of its peristaltic motion. Dr. 
Darwin attributes the effect to a suspension 
of the exciting power of pleasurable sensa- 
tion, in consequence of which the fibres of 
the stomach are arrested for a time, and 
at length, from the undue accumulation ot 
irritability, their action becomes inverted. 
The sensation of nausea does not, however, 
invariably precede the act of vomiting ; and 
even allowing this feeling to be a necessary 
prelude, the cause of the sensation itself is 
left unexplained by the sensorial theory of 
Dr. Darwin. 
The utility of emetics under some circum- 
stances of the system is very extensive. 
Their salutary effects are not solely referable 
to the discharge which they occasion; but 
they also produce other changes on the living 
body, both general and partial, which will be 
noticed in the article Medicine. 
Emetics are derived from the vegetable 
and mineral kingdoms. 
Emetics from the vegetable Kingdom. 
Ipecacuanha, ipecacuan, radix, South 
America. 
This root is the one in most general use 
as an emetic: it is both mild and certain in 
its operation. It is given in a dose from fif- 
teen to thirty grains. Ipecacuan is employ- 
ed in conjunction with opium, as a diapho- 
retic. In this case its dose is from three or 
four to ten grains. 
Sc ilia maritima , squill, radix, South of 
Europe. This bulbous 'root of a plant grow- 
ing on the sandy shores of Spain and Italy, is 
not at present in much use as an emetic : it is 
principally employed as an expectorant and 
diuretic. 
Sinapis alba, mustard, semen, indige- 
nous. This perhaps might have been classed 
among the aromatics. When employed as 
an emetic, its administration lias been prin- 
cipally confined to paralytic affections. It is 
given* in the doss of a tea-spoonful mixed 
with water. 
Asarum Europcvum, asarabacca, folia, in- 
digenous. The introduction of ipecacuan 
into practice, has almost superseded the use 
of this powerful drug. Dose twenty grains 
of the dried leaves ; of the dried root ten 
grains. 
Nicotiana tahacum, tobacco. 
This is a violent emetic, as well as nar- 
cotic. It is scarce ever employed in prac- 
| lice. 
From the mineral Kingdom. 
Antimonium , stibium, antimony. 
Thau antimony, scarcely any mineral is in 
more general use: it is, however, seldom 
vised but in a state of combination with oxy- 
gen or acid. Its preparations, doses, and 
virtues, will he treated of under the articles 
Pharmacy and Medicine. 
Sulphas zinci, sulphate of zinc. 
This salt is sudden in its operation: it is in 
principal use in cases of poisons having been 
received into the stomach. Its dose is from 
ten grains to a scruple. 
Sulphas cupri, sulphate of copper. 
Yol. II. 
MATERIA MEDIC A. 
Neither this nor the acetite of copper is 
in much use; they are violent in their opera- 
tion, and in no respect preferable to milder 
emetics. 
OF CATHARTICS. 
A discharge of the intestinal contents ap- 
pears to be occasioned by medicines upon a 
twofold principle. Cathartics either imme- 
diately excite the fibres of the intestines, thus 
accelerating their peristaltic motion, and con- 
sequent fecal evacuations, or they produce this 
effect more immediately by stimulating the 
exhalant and secerning vessels ; whose fluids 
(the bile, pancreatic juice, and intestinal 
mucus) act as solvents' to, and promote the 
discharge of, the feces. These latter are 
milder in their operation than the former: 
they are classed by Darwin among the se- 
cernentia. There are, however, many drugs 
which act at the same time in each of tiie 
above modes. 
Cathartics, still more than emetics, are ex- 
tensively employed in medicine, as capable 
of operating important changes throughout 
the system. Their use lias recently been 
brought more systematically into notice. 
Upon the grounds just stated, cathartics 
may with some propriety be divided into 
purgative and laxative. 
Purgatives. 
Cassia senna, senna, folia, Egypt, Arabia. 
This is frequently employed: it is given in 
the form of infusion. Dose a drachm or 
more. 
Rheum palmatinn, rhubarb, radix, Tartary. 
The best rhubarb is imported from Tur- 
key. The China rhubarb has less of the 
aromatic flavour. British rhubarb is much 
inferior to either. The dose of rhubarb, as a 
cathartic, is from fifteen grains to two scru- 
ples. It is given with advantage in diarrhoea 
and dysentery, as it contains an astringent 
principle. In small doses it is stomachic and 
tonic. 
Convolvulus jalapn, jalap, radix, Mexico. 
This is often administered both alone and 
more especially with calomel (submurias hy- 
drargyri). Its dose is from fifteen grains to 
two scruples. 
Helleborus niger, black hellebore, radix, 
Austria, Italy. 
This, in a dose from ten to twenty grains, 
is a violent cathartic. It is seldom employ- 
ed in modern practice. Dr. Mead attri- 
buted a powerful emmenagogue property to 
to it, which however has scarcely been re- 
alized by others. The undent physicians 
gave it freely in maniacal disorders. 
Bryonia. alba, bryony, radix, indigenous. 
This root is not much used. Dose from 
twenty to thirty grains. It is slightly diu- 
retic. 
Cucumis colocynthis, colocyntb, fructus 
pulpa, Syria. 
A drastic purgative in a dose from three to 
six grains. It is seldom given by itself. It 
lias been chiefly had recourse to in obstinate 
constipation. 
Momordica elaterimn, wild cucumber, 
fructus, south of Europe. 
This is the most violent of all purgatives. 
Its dose is half a grain to two grains. 
Rhai/inus eathartieus, buckthorn, bacca- 
rum succus , indigenous. This is seldom 
used. 
Aloe poj'oUala, socalriuc, Barbadoes, 
? 
J 13 
or hepatic and cabbalinc aloes ; succus spis- 
satu3, Africa, Asia, America. 
The socotrine aloes is the purest. r I he 
Barbadoes and hepatic rank next. T he cab- 
baline is the most impure, and is the weakest. 
Dose from fifteen grains to a scruple. Its. 
action is principally upon the larger intestines, 
and on account of the vicinity to, and sym- 
pathy of these with, the uterus, it is often 
useful in amenorrhoea. 
Convolvulus scatnmonia, scammony, gum- 
mi-resina, Syria. 
This is a very drastic cathartic. Dose 
from five to ten grains. 
Gambogia gutta, gamboge, gummi-resina, 
East Indies. 
Another violent cathartic. Dose from 
one to four or five grains. In conjunction 
with the last and following article gamboge is 
often administered in dropsy. 
Submurias hydrargyri , mild muriate of 
mercury, calomel. 
Dose* from five lo eight or ten grains. 
LAXATIVES. 
Manna, manna, fraxinus ornus, succus 
concretus, South of Europe. 
This is a mild and pleasant laxative. It is 
frequently given to children in conjunction 
with senna. Dose to an adult from one to 
two ounces. 
Cassia fistula, purging cassia, or cassia in 
the pod; pulpa fructus, Egypt, East and 
West Indies. 
Dose from four to six drachms. 
Tumurindus Indica, tamarind, fructus con- 
ditus, E. and W. Indies, America, Arabia. 
'The tamarinds of the shops, is the pulp of 
the tree mixed with seeds and small fibres, 
with a quantity of coarse sugar. 
It may be taken to the extent of two 
ounces, or more. 
Ricinus communis, palma Christi, oleum, 
semen, W. Indies, 
The oil from the nuts of palma Christi 
is the castor oil of the shops. This is a mild 
and very useful purgative. 
Sulphur, a simple inflammable substance, 
and magnesia, either pure or carbonated, are 
ail the laxatives that are afforded by the mi- 
neral kingdom. The operation of either is 
exceedingly mild. 
For the different neutral salts that are em- 
ployed as purgatives in medicine, sec Phar- 
macy. 
The purgatives that are administered Only 
in the form of enema, are the 
Marias soda, common salt. An ounce 
of this dissolved in a pint of tepid water with 
an ounce of expressed oil, forms the common 
domestic enema. 
Tercbinthina veneta, turpentine, pinus 
larix, gummi-resina. This is sometimes em- 
ployed as an enema triturated with the yolk 
of an egg. Dr. Cullen recommends this as a 
very certain cathartic. It is indicated in ob- 
stinate costiveness. 
Nicotiana. The introduction per-ano of 
tobacco smoke has sometimes been effectual 
in procuring alvine evacuation, after other 
cathartics have failed. The infusion of from 
one to two drachms in a pint of water is a 
more convenient mode of administering this 
medicine. Much caution is requisite in 
either case to obviate its injurious effects. 
OF EMMENAGOGUES. 
These are medicines which promote the 
menstrual discharge. Obstruction or reten- 
