There appears then to be some connexion between these two things.

Certain of the constituents of the bile are formed by the liver out of

the blood, for the purpose, apparently, of being again absorbed at some

part of the surface of the intestinal canal. One of these, Taurine, has

been shown to be chemically analogous to Quinine. Thus it seems to me to

be not improbable that this alkaloid may be of service in these

disorders by supplying the place in the blood of this biliary matter,

which for some reason may be needful in the animal economy, or that it

may actually become changed into the latter while in the system. Were

this proved, its restorative action would be effectually cleared up.

The Disulphate of Quinine (or Quina) is the preparation of the alkaloid

which is most commonly used.

Arsenic is used in Ague and intermittent disorders, and acts on the

Catalytic principle, but it is not serviceable in the other cases in

which Quinine is used. It is not a Tonic, nor does it seem to have any

relation to the function of the liver. I have thought it advisable to

restrict the term _Antiperiodic_ to the _Catalytics_ which are used in

Ague. (_Vide_ p. 141.) Quinine and Arsenic may both be employed in all

disorders which put on an intermittent or periodic type. The chief of

these is Ague, or Intermittent Fever. It is perhaps easier to arrest the

disorder by Quinine than by Arsenic; for Quinine may be given in large

doses, which cannot be done with Arsenic. But the administration of the

latter may be continued during the paroxysm, when the great febrile

reaction forbids the use of the other. The dose of Quinine is apt to

disagree with an irritable stomach, and to increase the fever. It is

generally laid down that this remedy should not be administered when

there is a quick hard pulse, or heat and dryness of the skin. Some,

however, have lately ventured to prescribe it to patients in high fever.

It appears that there is a particular class of patients which in such

cases will bear the administration of Quinine with impunity; while

others are unfavourably affected by the smallest dose.

It is perhaps at all times advisable to arrange so that the medicine

shall, if possible, be taken after meals, for it is less likely to

irritate a full stomach. And when it is thought proper to give it to a

patient in fever, a small dose of Tartar Emetic or Ipecacuanha should be

conjoined with it--not, of course, sufficient to produce vomiting, but

so that an increase of the febrile excitement may be prevented.

Quinine is in all cases better tolerated by the stomach when the dose is

considerably diluted with water.

A combination of Quinine and Iron is often of great service in feeble

and relaxed conditions, where there is co-existent Anæmia. (_Vide_ p.

129.)

IRON.

Class I. Div. I. Ord. V. CHALYBEATA.

It has been shown, in the article on Chalybeates, that the action of

Iron is of a distinctly Restorative nature.

There is in the blood a red colouring matter, called Hæmatosin. It is

found by chemical analysis that Iron is an essential part of this

substance. The existence of the right amount of Hæmatosin in the blood

is of vital importance. It is contained in the red globules of the

blood. When it is diminished in quantity, the number of these red

globules is lessened in the same proportion. This produces a paleness of

all the tissues, an inactivity of the muscular fibre, an impairment of

all the animal functions, and a general languor and debility of the

whole frame. This is Anæmia.

In all cases in which Iron is used there is a deficiency of this red

colouring matter; and in all instances of Anæmia Iron is appropriate as

a remedy. The blood has been analyzed before its use, and found to

contain a smaller quantity of Hæmatosin and fewer red globules than in

health. After its employment the blood has been analyzed again, and it

is found that the amount of Hæmatosin and of red globules is increased.

Iron, then, is given in Anæmia. It is also given in cases of Scrofula,

Cancer, Chorea, Hysteria, and other disorders, when these are attended

with Anæmia. When this last condition is wanting, it seldom proves

efficacious.

Iron, when given in moderate doses, remains in the system, and enters

into the composition of the blood. It is then a Restorative Hæmatic.

Some of the salts of Iron are also Astringent. Thus the Sulphate and

Sesquichloride may, by their topical action on the stomach, be of

service in cases of atonic Dyspepsia.

In Anæmia produced by special causes, as by scrofulous or nervous

disorder, we may often do most good by striking at the root of the

evil,--employing a Catalytic medicine which shall be able to do this. In

simple Anæmia, Iron is of more use than any other medicine. It should be

combined with exercise, air, light, and good living. In other disorders

a combination of drugs is frequently of use. In chronic Ague, and in

many cases of debility, Iron and Bark may be given together. Iron and

Aloetic purges may be prescribed in Chlorosis and Amenorrh[oe]a. A mild

purgative should be occasionally given in all cases in which Iron is

used. The Ammonio-citrate of Iron,--the compound Iron mixture, which

contains the Carbonate,--and the Tincture of the Sesquichloride,--are

perhaps the best of the officinal Chalybeate preparations. The first of

these is the mildest, and the last the most irritant of the three.

(_Vide_ pp. 145, 263.)

ANTIMONY.

Class I. Div. II. Ord. I. ANTIPHLOGISTICA.

Class II. Div. III. Ord. II. SEDANTIA SPECIFICA.

Class IV. Ord. II. EXPECTORANTIA.

Class IV. Ord. V. DIAPHORETICA.

The best Antimonial for general purposes, and the most characteristic in

its mode of operation, is Tartar Emetic. In this medicine are exhibited

three distinct varieties of action. The first of the terms which are

applied to it above implies that it has a Catalytic action in the blood.

As a Special Sedative, it is able to cause nausea and vomiting. And it

acts upon the glands as an Eliminative; being a Diaphoretic and an

Expectorant.

I have found it convenient to restrict the term _Antiphlogistic_ to

those medicines which counteract the inflammatory process by an action

in the blood. In this sense it is applicable to Antimony; although this

medicine is still better able to subdue inflammation by its powerful

neurotic action.

The operation in the blood is naturally slower than the action on nerve,

and is therefore less marked, and less immediately applicable. Antimony

deteriorates and impoverishes the blood in very much the same way as

Mercury, and, if given in small and carefully regulated doses, is simply

a mild Antiphlogistic and Eliminative. It tends to increase all

secretions, but particularly the exhalation from the skin and lungs,

independently of the production of nausea (p. 324,) a symptom which is

not brought on by a small dose. It is probable that a diaphoretic dose

of Tartar Emetic is actually eliminated from the skin and mucous

membranes. Antimony is appropriate as a Diaphoretic in high fevers, and

in cases where Opium could hardly be used. But Opium is preferable in

cases where there is gastric irritation, and a weak compressible pulse.

The action by virtue of which Antimony has gained its high reputation

as a medicine is of a different kind. By an influence on a part of the

nervous system, apparently the Vagus nerve, it produces first the state

called nausea, and afterwards vomiting. The most important symptom in

this nausea, and in the state of system which succeeds the vomiting, and

continues for some time after it, is a depression of the action of the

heart. At the same time the muscular system is relaxed, and the

breathing is rendered slower.

This nausea is not produced to any extent by a mere irritant Emetic,

such as Sulphate of Zinc, which acts externally and takes effect

immediately. The Antimonial cannot act so quickly; part of it must first

be absorbed, so that it may reach the nerve. We know that it does not

act by outward irritation, from the fact that if the solution be

injected into the veins at any part of the body, it will equally produce

nausea and vomiting. Antimony has no direct action upon the brain; it

affects only a part of the nervous system. In the nausea we recognise a

sedative action upon the nerves of the heart; and in the slow breathing

a similar action upon the nerves of the lungs. But it may be objected

that the production of vomiting is not a sedative action, for we know

that the same symptom may be caused by a mere external stimulant. And

yet there are several reasons which have induced me to conclude that

this also is a sedative action. It would be inconsistent to suppose that

Antimony could be a Sedative in producing nausea, and a Stimulant in

causing vomiting. We have already noticed that a Sedative medicine may

affect nervous force in either of two ways; it may derange it, or it may

depress it. (p. 243.) That influence which causes the contraction of the

stomach to commence at the pylorus, and to result in the expulsion of

its contents upwards along the [oe]sophagus, is obviously explained by

an action of derangement, for it is an exact reversal of the natural

state of things. (p. 92.) But the effects of derangement are often very

similar to those of excitation. Thus convulsions of the muscular system

are caused by Hydrocyanic acid, a Sedative,--and by Strychnia, a

Stimulant; and vomiting is producible by Tartar Emetic, a Sedative,--or

by an external irritant of the mucous membrane.

It is by the production of nausea that Antimony becomes so valuable an

agent in the control of high fevers and acute inflammations. The force

of the heart being diminished, the fever is allayed; and the active

congestion of the vascular system, whether local or general, which was

produced by the inflammation, and maintained by the violent action of

the heart, is effectually subdued. At the same time absorption is

favoured by the removal of the pressure from the capillary circulation.

For its power therefore as a Special Sedative, by which it produces

nausea, Antimony is used in sthenic inflammations generally, especially

in those that are rapid, and in which we desire a sudden and powerful

action. In such cases it is preferable to Mercury,--which is a simple

Antiphlogistic, acting in the blood, and having no operation on nerve.

It is thus indispensable in Croup. It is very efficacious in sthenic

Pneumonia. Laennec speaks highly of its use in acute Bronchitis. In

Fevers, Dr. Graves recommends that it should be combined with Opium. In

inflammations of the lungs it is particularly applicable, for it exerts

a sedative influence over the nerves of those organs.

If a small dose be constantly repeated, and gradually increased to a

large one, the system will at length be induced to tolerate the

medicine, and it will not produce vomiting. Laennec recommended that it

should be given in this way in inflammations. He considered the

production of vomiting unadvisable; for by that act the system is

temporarily excited, and a large quantity of the medicine rejected,

which should have been absorbed into the blood to work out its action

there. The soundness of his views on this point has been generally

admitted by those who have succeeded him.

Given simply as an Emetic, this medicine has been used in the early

stage of acute local inflammations, as Ophthalmia and Gonorrh[oe]a. It

may cut these short at their outset, by hindering the tendency of the

local irritation to excite the force of the heart. When we wish simply

to evacuate the stomach, as in a case of poisoning, an irritant emetic,

as Mustard or Sulphate of Zinc, which acts at once without producing

nausea, should be preferred, for three reasons. Its operation is more

rapid. The distressing condition of nausea would be an aggravation of

the existing mischief. And the production of nausea, by taking off the

pressure from the vascular system, favours absorption, which is the very

thing that we wish to avoid. The object of an antimonial Emetic is not

so much to empty the stomach as to make a powerful impression on the

system.

The influence of Antimony on the glandular organs is indirectly but

powerfully intensified by its nauseant action. In small doses it is a

simple Expectorant; in nauseant doses, it assists expectoration by

relaxing the bronchial tubes, and diminishing the number of the

respirations. In a small dose it is Diaphoretic; but in large doses it

may cause copious sweating, by favouring the absorption of fluid into

the blood, and dilating the capillaries and pores of the sudorific

glands. In inflammatory habits a small addition of Tartar Emetic forms a

powerful adjunct to a purgative dose; for by it the absorption of the

other medicine is assisted, and at the same time an over-tonicity of the

muscular fibre of the intestine may be diminished. But in relaxed

conditions of the system, where the intestine is apt to be over-dilated,

and Catharsis is favoured by Tonic medicines,--Tartar Emetic would

hinder it.

Ipecacuanha, a vegetable substance, resembles Antimony in all its

operations, excepting its blood-action. It is less potent as a

Neurotic; less efficacious as a Diaphoretic; but excels it as an

Expectorant. (_Vide_ pp. 93, 168, 185, 249, 283, 298.)

MERCURY.

Class I. Div. II. Ord. I. ANTIPHLOGISTICA.

Class I. Div. II. Ord. II. ANTISYPHILITICA.

Class IV. Ord. III. CATHARTICA.

Class IV. Ord. IV. CHOLAGOGA.

There are three principal forms in which this medicine may be exhibited.

Blue pill contains the metal itself in a finely divided state, as well

as a small quantity of the oxide. Calomel is an insoluble Chloride of

Mercury. From the great similarity that exists between the action of

these two it seems likely that they are reduced by the gastric fluid to

the same condition. Both must be rendered soluble (p. 88) before they

can be absorbed. Probably they are both absorbed in combination with the

acid of the stomach.

Bichloride of Mercury is soluble in water, and probably absorbed

unchanged. It differs from the other two as a medicine, partly, but not

entirely, on account of its solubility. The dose required is smaller,

for it is much more powerful. It is also much more irritant, being in

large doses a corrosive poison, and often producing soreness of the

throat and of the urinary passages. Thirdly, it is less likely to

produce salivation. It is more adapted for chronic than for acute

diseases.

As Hæmatic medicines, Mercurials have a double action. They counteract

inflammation in general, and the poisons of Syphilis in particular. They

thus belong to the first and second orders of Catalytics.

Mercury deteriorates the blood, diminishing in it the amount of fibrine

and corpuscles. As an anti-inflammatory agent, it may be thus compared

with Antimony and Blood-letting. The immediate effect of Blood-letting

is mechanical; that of Antimony, nervous; that of Mercury, hæmatic.

Blood-letting weakens the force of the heart by diminishing the pressure

on the vessels; Antimony diminishes the pressure on the vessels by

weakening the force of the heart; and Mercury does both of these things,

by impoverishing the blood. Thus all of them favour absorption, and

counteract effusion; but, from its nature, the action of Mercury is

slower than that of the others, and for the same reason more lasting. To

produce this action on the blood, the Mercurial should be continued

until some effect on the mouth is perceived, but not so as to cause

copious salivation. This symptom is a sign that the blood is

sufficiently saturated with the medicine. This point will be sooner

reached if the Mercury be conjoined with Opium, so as to prevent it from

passing out directly by the bowels. Any ill result is less likely to

occur if the patient be kept warm and quiet while under the influence of

the medicine. On account of the durable and effectual nature of its

action, Mercury is of great use in preventing the process of effusion,

and in causing the absorption of effused products. It is thus employed

with advantage in Pleurisy, and in other membranous inflammations. Next

to these, it is most useful in inflammations of the liver and brain. It

is inferior to Antimony in fevers and rapid inflammations, because

slower in operation, and without any direct action on the nervous

system.

In cases of primary Syphilis, Mercury is by far the best medicine with

which we are acquainted. It should be used in all cases except where

there is deep-rooted scrofula, or marked debility, or a sloughing and

irregular condition of the primary sore. (Dr. Pereira.) It should always

be given in Iritis. In Periostitis, and secondary eruptions, Iodide of

Potassium is generally preferable.

Mercury, being unnatural to the blood, passes at length out of the

system through the glands, and acts as an Eliminative. Like Antimony it

tends to increase all the secretions in the body. But whereas Antimony

acts especially on the secretions of the skin and pulmonary membrane,

Mercury tends particularly to excite the functions of the liver and

bowels, being Cathartic and Cholagogue. Of its true eliminative action

we have better proof than has yet been obtained in the case of Antimony;

for Mercury has been found to pass into the alvine excretions, by M.

Lehmann; and discovered in the bile of dogs to whom it had been

administered, by M. Buchheim.

For the purpose of acting upon the liver and bowels, Mercurials are

frequently used in disordered digestion and cases of hepatic

derangement. In Intermittent disorders, debility, Gout, Rheumatism, and

Scrofula, small doses of Mercury are often of service. I have

endeavoured to show (p. 143) that in these cases they may prove

indirectly tonic, by restoring to the system some of the wanting

elements of bile, which are normally secreted by the liver for the

purpose of being reabsorbed into the system.

In incipient and chronic cases of Scrofula, consumption, and mesenteric

disease, it is possible that Mercurials may act yet in another way. They

no doubt stimulate the formation of the Pancreatic secretion, which is

similar in nature to the saliva. By doing so they may assist the

absorption of the fatty matters of the food in the case of thin and

emaciated subjects, in whom it is probable that the function of this

gland is frequently impaired. (_Vide_ p. 313.)

Mercury assists the operation of all other medicines which act upon the

secretions. In cases of hepatic dropsy it helps the action of Diuretics,

and tends to remove the cause of the congestion, by stimulating the

function of the liver.

The blood-operation of Mercury, by which it is enabled to counteract

morbid processes, is involved in considerable obscurity. The same must

be said of all Catalytic medicines (_Vide_ p. 179.) Dr. Billing

(_Principles of Medicine_, p. 73) is of opinion that Mercury acts by

contracting the capillary vessels. I have already stated my reasons for

dissenting from this notion. (p. 163.) The same author denies the

specific action of Mercury in Syphilis. But if we only admit that there

is no other medicine that will cure primary Syphilis so well as Mercury,

we cannot then surely deny that its action in that disorder is of a

special nature. He considers it to be neither stimulant nor

sedative,--but tonic. (_Op. cit._ p. 101.) No one of these terms appears

to me to be strictly applicable, but perhaps the last is the best of the

three.

Some have, without sufficient reason, assumed Calomel to be a Sedative

when given in large doses. To act in this way, very large doses have

been recommended and given in fever and malignant cholera. Calomel is

naturally an insoluble substance; and in these cases the function of

absorption is at the very lowest ebb; so that it is probable that the

large doses are often left unabsorbed, and pass out of the bowels very

much as they entered, producing scarcely any more effect than so much

chalk mixture. (_Vide_ pp. 88, 143, 163, 168, 185, 188, 203, 286, 295,

308.)

IODINE.

Class I. Div. II. Ord. II. ANTISYPHILITICA.

Class I. Div. II. Ord. III. ANTISCROFULOSA.

The readiest and best way of obtaining the beneficial effects of Iodine

is by the use of Iodide of Potassium. This is a very soluble salt. The

peculiar virtues of Iodine are not impaired, but rather improved, by its

chemical combination with the alkali. And when we administer the Iodine

itself, as in the tincture, there is no doubt that after entry into the

blood it combines with some alkaline base.

If the use of Iodine be continued for some time it has the effect of

impoverishing the blood. It sometimes produces a vesicular eruption on

the skin, and causes a considerable degree of irritation of the mucous

membrane of the nose and eyes.

The preparations of Iodine exert in the blood some special actions of a

Catalytic kind, by virtue of which they are enabled to counteract the

morbid actions of secondary Syphilis and of Scrofula. Iodine is not,

like Mercury, a general Antiphlogistic; but it is a stimulator of the

function of absorption, as are all the medicines that tend to impoverish

the blood. This action in causing absorption can be no explanation of

the blood-operations for which it is employed; for these are peculiar to

it alone, whereas the other property is shared by other remedies. (p.

192.)

Iodine is an Antisyphilitic. But this term is not applicable to it in

exactly the same sense as to Mercury. Its use is confined to the later

symptoms,--to Periostitis, and the late eruptions, as Rupia. Sometimes

it even fails in these. This is generally when the primary disorder has

not been met by Mercury. Some preparation of Mercury should then be

administered for awhile; and the Iodide of Potassium may be given

afterwards. Thus the disorder which is controlled by the latter medicine

is so modified as to be something quite distinct from the primary

Syphilis.

The same medicine is an Antiscrofulic. It is applicable in all the forms

of Scrofula, and in Goitre. Possibly it acts differently in such cases;

but it is certain that there is often, in cases of confirmed Syphilis, a

cachexy similar to that produced by Scrofula. In either disorder, when

this cachexy is confirmed, Mercury is most objectionable. On the

contrary, in primary Syphilis, and even in incipient Scrofula, Mercury

may be used.

Like all potent remedies, Iodine requires to be carefully used. It is

sufficient to give it in small doses. If given in large doses, and too

long continued, it causes a deterioration of the blood, followed by an

emaciation of the whole frame. So vigorously was this medicine used by

the Swiss practitioners after its first discovery, that serious

consequences, as the absorption of the mammæ or the testes of healthy

individuals, are said to have ensued in several cases. By these mishaps

their faith in its utility was much shaken. But M. Magendie states that

he has never known such a thing to occur; and M. Lugol, the most devoted

and enthusiastic of all the advocates of Iodine, has observed that

scrofulous patients frequently become fattened during its employment.

The therapeutic actions of Iodine have been ascribed by Dr. Billing to a

contraction of the capillary vessels; by Dr. Pereira, to a liquefaction

of the blood; by others, to a direct stimulation of the absorbent

system. It probably counteracts morbid operations in some way that we do

not understand. It is one of those medicines which tend to increase

secretion in general. It appears to act most upon the urine, but is not

a powerful Eliminative. It has been chemically discovered in the blood,

urine, and sweat; as also in the saliva, tears, and nasal mucus, which

secretions are apt to be increased in quantity during its action.

The Iodide of Potassium should be cautiously administered to excitable

patients, as it sometimes acts as an irritant. When the stomach is

irritable, it should be given after meals, and the dose considerably

diluted with water.

A bronchocele, to be benefited by Iodine, should consist of a simple

enlargement of the gland, not of very long standing, nor painful to the

touch. All scrofulous affections, whether of the glands, joints, liver,

or other parts, are more or less benefited by the use of Iodine. Iodine

has been used in simple enlargement and induration of various organs,

particularly the uterus. Dr. A. T. Thomson speaks highly of its efficacy

in ovarian dropsy.

It is probable that Chlorine, Bromine, and their compounds, closely

resemble the preparations of Iodine in their therapeutic operations.

(_Vide_ pp. 169, 188, 191, 306.)

COLCHICUM.

Class I. Div. II. Ord IV. ANTIARTHRITICA.

Class II. Div. III. Ord. I. SEDANTIA GENERALIA.

Class IV. Ord. III. CATHARTICA.

The majority of medicines that affect the blood permanently belong to

the mineral kingdom, while most of those that powerfully impress the

nerves are derived from vegetables. But to the rule that Hæmatic

medicines are of mineral origin, we have already found one important

exception in the case of Quinine and Tonics. Colchicum appears to be

another instance of the kind. The great and obvious use of this remedy

is that action in the blood which above is classed first, i.e. its

influence in the counteraction of gouty disorders. We have already

considered at some length (p. 200) a number of Antiarthritic medicines

that seem to act in a chemical manner. Colchicum is not one of these. It

is a General Sedative, and a Cathartic; in large doses, an irritant

poison. It seems also to increase the amount of other secretions,

particularly the urine and the bile. But it is used beneficially in

Gout; and it is assumed that in the cure of this disorder it exerts an

action in the blood, inasmuch as its remedial operation appears to be

independent of its nervous and glandular actions. This hæmatic action

must be of the Catalytic kind, and may probably consist in the exertion

of a special influence over the erring assimilative processes, which

tends to resolve them into a right direction.

But it should be observed that at least three other explanations of the

action of this remedy have been proposed, each of which is possessed of

a degree of plausibility.

Some have ascribed its efficacy to the union of a cathartic with a

sedative effect, and have even substituted for it a combination of Opium

with a drastic purgative. Those who adopt this view of its action aver

that Colchicum acts best when it purges freely. But though Purgatives

are often of use in gouty disorders, it is generally found that

Colchicum operates most favourably when given in too small a dose to

produce any purging.

Colchicum stimulates the function of the liver, which is generally

deranged in gouty disorders. Mercury, which also promotes the secretion

of bile, is in this way useful in Gout. It seems that the formation of

this secretion is in some manner essential to the integrity of those

blood-processes which are disturbed in arthritic diseases. It might

therefore be supposed that Colchicum too acted as a Cholagogue. But it

is not clear that it increases the secretion of the bile in any very

marked degree.

Thirdly, it is affirmed by some that this medicine is of use in

eliminating uric acid from the blood, this product being supposed to

accumulate in the system before the paroxysm of Gout. It is said that

under the action of Colchicum the natural amount of this substance in

the urine is much increased. This would be an important fact if it were

certainly proved. But it does not seem to be so; nor is it clearly shown

that the observed increase in uric acid is not a symptom of the

disorder, rather than of the treatment.

Colchicum is more or less applicable in the gouty forms of Rheumatism,

in Lithiasis, and in acid dyspepsia, but it is most efficient in the

simple gouty paroxysm.

There are several objections to the indiscriminate use of this remedy.

Some have observed that though it cures for a time the gouty attack, it

causes the next assault of the disease to recur more quickly than it

would otherwise have done. The dose also certainly requires to be

considerably increased on each successive occasion. Sometimes this

medicine produces a great depression of the spirits. Dr. Todd believes

that Colchicum has often a tendency to change the common acute form of

Gout into an asthenic form which is less amenable to treatment. So

that, altogether, it is perhaps a good rule to treat the patient without

Colchicum as long as it can be done with safety, adopting this medicine

only as a last resource, when other remedies have been tried and failed.

It ought rarely to be used in Rheumatism. In the asthenic form of Gout,

or in old chronic cases, when there are chalk-stones on the knuckles,

Quinine, Stimulants, and Purgatives, constitute the best treatment.

Alkalies and Mercurials may prove serviceable in acute cases.

But it is certain that in many cases of this painful disorder Colchicum

gives immense relief; and it often seems to be the only medicine that is

capable of doing so. (_Vide_ pp. 194, 247.)

ARSENIC.

Class I. Div. II. Ord. VI. ANTIPHRIODICA.

Class I. Div. II. Ord. VII. ANTICONVULSIVA.

Class I. Div. II. Ord. VIII. ANTISQUAMOSA.

This medicine has already been noticed at considerable length in the

account of the last three orders of Catalytic medicines. It is again

noticed here as one of the most remarkable of those mineral substances

that are used to counteract blood-disorders. It appears to be capable of

exerting no less than three kinds of action in the blood, which

operations result in the counteraction of Periodic disorders, Convulsive

diseases, and certain Cutaneous eruptions. That must of necessity be a

various and obscure agency, which is gifted with the power of arresting

and controlling so great a variety of morbid actions.

It would seem that Ague and its kindred disorders are capable of being

combated and cured in two different ways; by Restoratives, such as

Quina, which appear to supply the blood with a certain needful material;

or by Catalytics, as Arsenious acid, which operate by antagonizing a

morbid action, which is either the cause or the result of the

blood-disease. I have given my reasons for ranking Quina and Tonics

among Restorative medicines. The following are the principal grounds for

which Arsenic is included among Catalytics. It is unnatural to the

blood, and is at length excreted from the system. It acts as a poison;

and is able to work out in the blood a certain process of its own. It

has no sudden action on the nervous system, like that which is possessed

by Neurotic medicines. And it is able to counteract a number of

disorders, as Lepra and Impetigo, which are assumed to depend upon

morbid actions in the blood.

Arsenic has been recommended in Syphilis, but it exerts no marked power

over that disorder. In ague it possesses this advantage over Quina, that

it may be administered with safety during the paroxysm. The ordinary

precautions in the administration of the Arsenical solution (Liquor

Potassæ Arsenitis) have been already enumerated, viz., that the dose

should be small at first, and afterwards gradually increased; that as

soon as it produces swelling of the face and eyelids, or irritation of

the stomach, it should be discontinued, or the dose reduced; and that it

should generally be given on a full stomach, as it is then less likely

to irritate. (_Vide_ pp. 140, 165, 170, 176, 207, 211, 213.)

AMMONIA.

Class I. Div. I. Ord. III. ALKALIA.

Class II. Div. I. Ord. I. STIMULANTIA GENERALIA.

Class IV. Ord. II. EXPECTORANTIA.

Class IV. Ord. V. DIAPHORETICA.

This medicine may be taken as the type of simple General Stimulants. It

tends to excite the nervous forces generally. The remedies of this group

are not very potent in their action, Ammonia being perhaps as powerful

as any of them. Alcohol, an Inebriant Narcotic, produces at first a

greater stimulant effect, but its action is followed up by a depression

of the nervous forces, and an affection of the powers of the mind. This

influence over the intellectual functions is confined to the Narcotic

division of nerve-medicines, and is not possessed by Ammonia.

Ammonia is capable of acting chemically as an alkali in the system, and

may be used in the various cases in which alkalies are wont to be

employed; but it is inferior to Potash in such disorders, because its

affinities are far less powerful than those of that alkali. It is also

caustic and irritant when applied externally in any form.

Administered internally in solution, it has a power of quickening the

action of the heart, and exciting the circulation generally. It is

therefore particularly useful in the common case of fainting, or

threatened syncope. This stimulant power is possessed only by the free

alkali and its carbonates. And as the secretion of the stomach is acid,

Dr. Pereira supposes that the free or carbonated Ammonia becomes

neutralized before absorption; that it is therefore unable to act in the

blood except as a salt, and can only operate as a Stimulant while in

contact with the coat of the stomach. Its influence must then be

conducted by the nerves from the surface of the stomach to the heart.

But though the nerves are the natural channels of various motor and

sensory impressions, it is to assume an unprecedented thing to suppose

that a medicinal action can be transmitted by their means to a distant

part. For this and for other reasons it seems to me to be most likely

that the solution of Ammonia is absorbed too fast in the stomach to be

neutralized by the gastric juice. Or even if it were neutralized before

absorption, it would probably be again set free on entrance into the

blood, in which there is a slight excess of alkaline matter. Thus

Ammonia would exist in the blood in a free state, except in those morbid

conditions in which there is a general excess of acid in the system. I

suppose the same to be the case with Potash, when it is given in any

quantity. The great diffusibility of the free Ammonia would be an

additional reason for its rapid absorption. When the gas is inhaled, as

in the use of smelling-salts, and applied thus to the nasal and

pulmonary mucous membranes, it must pass through to the blood in a free

state, for these surfaces do not secrete an acid. And yet its effects in

this case are the same as when it is taken into the stomach, which

further renders it probable that in the latter instance it is absorbed

free.

When there is an excess of acid in the system, Ammonia may be used as a

Restorative. It diminishes the acid reaction of the secretions by

combining with the acid to form a salt.

In ordinary conditions (_i.e._ when not required in the system) it has

to be excreted from the blood. Both Ammonia and its salts act as

Expectorants and Diaphoretics, being excreted on the mucous surface of

the lungs, and on the skin. Free Ammonia is a better Expectorant than

any of its neutral salts. The secretion of sweat contains an acid. The

Ammonia which passes out on the skin combines with this acid. But on the

pulmonary surface it is probably excreted free. For it is found that the

careful inhalation of Ammoniacal gas has the same effect in augmenting

the mucous secretion as the internal use of Ammonia. Ammonia is

volatile, and soluble in air; and tends for that reason to pass off

freely from those secreting surfaces which are immediately in contact

with the atmosphere. (p. 278.)

It is supposed by some that diffusible Stimulants act simply on the

ganglionic system of nerves, being able through them to excite the

functions of the heart, vessels, and glands. But Ammonia is used with

advantage in some cases in which the whole nervous system is implicated

in the disorder. It has been employed in cases of Typhus, of simple

febrile exhaustion, of Hysteria, Epilepsy. In such affections the brain

is at least involved, if not often the chief seat of the disorder.

Spasms and convulsions are due to a general derangement of the nervous

forces, and particularly of the brain, in which these centre and

originate. Stimulants, by exalting the natural functions, counteract and

control this derangement. It is thus that Ammonia and volatile oils are

of use in convulsive disorders; but they are seldom of any permanent

efficacy, as in most cases of Hysteria and Epilepsy there is at the

bottom a blood-disease, of which the spasmodic fits are only the symptom

and outbreak. (_Vide_ p. 176.) So also is there a limit to the

efficiency of Stimulants in such cases as Typhus fever; there is a

certain point of exhaustion beyond which they are of no avail. For I

have attempted to show that though Stimulants are competent to exalt

nervous force, they are unable to supply vital force. A degree of

nervous force is necessary to the continuance of life; but when the

powers of life themselves are ebbing away, it is impossible then to

prolong any further the thread of existence by the exhibition of

stimulant medicines.

The action of Ammonia is directly the reverse of that of Prussic acid,

which is a General Sedative, producing Convulsions and Syncope. Ammonia

is thus used in cases of poisoning by that liquid. (_Vide_ pp. 126, 227,

278, 283, 301.).

STRYCHNIA.

Class II. Div. I. Ord. II. STIMULANTIA SPECIFICA.

Strychnia is the chief alkaloid and active principle of Nux Vomica. This

medicine is comparatively simple in its action. It has no claim to the

title of Sedative, which is sometimes applied to it. It does not affect

the nerves generally. It has no direct action on the brain, but

stimulates chiefly the function of the spinal cord, and its system of

nerves. Of these nerves it affects the motor considerably more than the

sensory branches. Along with the spinal cord, it doubtless also acts

upon that part of the brain which is immediately associated with the

spinal system of nerves. But the function of reflex motion, which is

thought to reside in the spinal cord, is particularly stimulated.

Strychnia is thus an exciter of muscular contraction and of motion;

exalting sensation in a less degree. It has also apparently some action

on part of the ganglionic system of nerves, by which it is enabled to

promote the function of the stomach, and becomes temporarily a tonic

when given in relaxed conditions of that organ. But it does not excite

the action of the heart.

In cases of poisoning by Nux Vomica, the brain and the heart are

unaffected. Tetanic and general convulsions are produced; and the

immediate cause of death is a spasm of the muscles of respiration.

Strychnia causes a contraction of the muscles by stimulating the motor

centres, and originating in them an impulse which is propagated along

the motor nerves. So that when these centres are diseased, or the

continuity of their fibres destroyed, it is unable to exert its power.

It is used as a medicine in cases of Paralysis. But when the lesion of

the nervous centre is of recent occurrence, or when it has been of so

serious or extensive a nature as to admit of no repair in the course of

time, the remedy will be ineffectual. It is only successful in cases

where the injury to the nervous centre has healed up, and where the limb

continues paralyzed merely because the motor nerves have lost the power

to transmit the necessary impulse, from having been so long unaccustomed

to the discharge of this office.

As it is able to act on the nerve itself, it is sometimes thought best

to apply it to the affected part on a raw surface produced by a blister.

The advantage of this plan is most obvious in the case of Lead-palsy,

where the cause of the paralysis is local, residing in the nerve, and

not in the centre. But in this case also it is necessary that the

nerve-centre be sound. Dr. Neligan recommends Strychnia in Lead-colic,

in which disorder constipation and distention of the bowel are produced

by a paralysis of a portion of the large intestine.

Strychnia has been used with benefit by Dr. Golding Bird in cases of

Phosphaturia connected with a functional derangement of the spinal cord.

(_Vide_ p. 232.)

ALCOHOL

Class II. Div. II. Ord. I. NARCOTICA INEBRIANTIA.

Class IV. Ord. V. DIAPHORETICA.

Class IV. Ord. VI. DIURETICA.

We have already considered in order the peculiarities in action that

distinguish Narcotics alike from Stimulant and Sedative medicines; how

they tend first to exalt the nervous forces, and then to depress them,

and have further a particular action on the intellectual part of the

brain. We have observed that these remedies may be divided into three

minor groups, which differ considerably, if only regarded in their

action on the nervous forces generally. For that Inebriants approach

very nearly to Stimulants, and Deliriants to Sedatives, while Soporifics

occupy an intermediate place. We have seen also that though, during the

stage of stimulation, these three orders tend all more or less to excite

the powers of the mind, they differ characteristically in their

secondary or depressing effect upon the same. That, with respect to our

present purpose, the intellectual functions may be divided into three

parts: the mind itself; volition and sensation, by which it is united to

the body; and the special senses, by means of which it is connected with

external things. And that the secondary or depressing action of

Inebriants is such as to _impair_ these three in a tolerably equal

degree; that of Soporifics _extinguishes_ for a time sensation,

volition, and the five senses, while it may leave the mind unaffected;

but that of Deliriants _excites_ and _deranges_ all the intellectual

functions.

If these things are borne in mind, the physiological action of Alcohol

will be tolerably understood when it is said to be an Inebriant

Narcotic. But it must be observed that when given in small quantities

its stimulant effect may be the chief action manifested, its secondary

sedative effect may hardly take place, and the production of

Inebriation, or drunkenness, may be altogether avoided. So much is this

the case that Alcohol is by some regarded as a Stimulant. But the same

thing is remarked of Opium, though in a less degree. And the effects of

a large dose of Alcohol are sufficiently obvious to indicate its place

amongst Narcotics. For the state of Inebriation may even pass on into

coma, and death.

In small quantities, for the purpose of producing exhilaration, and of

overcoming various depressing causes which are of daily occurrence,

alcoholic liquors of various kinds, Beer, Wine, and Spirits, are

habitually employed by a large portion of mankind. On the broad and

important question of their use and abuse as articles of diet this is

not the opportunity to enter.

In the form of Brandy (which is more agreeable to the palate,) Alcohol

is applicable as a medicine in low Fevers, in asthenic Erysipelas, in

Typhoid forms of Pneumonia, and in Collapse or Syncope produced by

surgical injuries or other causes. It restores the action of the heart,

and enables the system to bear up against the disorder. The stimulant

action may be maintained, and the secondary sedative effect prevented,

by a continual repetition of the dose. Thus when once the employment of

this stimulant has been determined upon, it should be steadily and

unremittingly persevered in until decided symptoms of improvement have

shown themselves in the patient.

The tendency of the practice of the present day is towards a freer use

of Stimulants, and a more sparing employment of blood-letting and

antiphlogistic agents, than was some time ago prescribed. And this is

probably an advance in the right direction; for in morbid actions there

is altogether very little that is really sthenic; and it is, as a

general rule, a wiser thing to support the system against the wearing

action of a disorder, than to add to the heap of its various troubles

another depressing cause.

But Alcohol is a potent agent for evil as well as for good. When large

quantities are taken continually for a considerable length of time, it

is capable of producing a chronic injury of the brain and mind. By

impairing the function of the former, it brings on the shaking paralysis

of Delirium tremens. By an action on the mind, it causes the strange

hallucinations and the habitual despondency which characterize that

disorder. Habitual drinking may likewise cause a chronic inflammation of

the liver, called Cirrhosis, which is succeeded by Dropsy. Alcohol is

absorbed by the stomach; and, on passing through the Portal vein to the

liver, may there produce this condition of the organ by the continual

irritation which it excites.

When taken in considerable quantity Alcohol passes out of the system by

the skin and kidneys, and thus acts as a Diaphoretic and Diuretic.

But Liebig states that when taken in small quantities it does not pass

off in the secretions, but is consumed or burnt in the system into

Carbonic Acid and water. He has found that persons who are accustomed to

take Beer in moderation require less bread in their food. (_Animal

Chemistry_, Part I., p. 96.) And as it contains more Hydrogen than

starchy food, and by the combustion of this Hydrogen the animal heat is

partly maintained, Vierordt has shown that during the use of alcoholic

liquors the amount of Carbonic Acid exhaled by the lungs is diminished.

Thus Alcohol may be regarded as one of the calorifacient articles of

food. (_Vide_ pp. 234, 237, 241, 255.)

CHLOROFORM.

Class II. Div. II. Ord. I. NARCOTICA INEBRIANTIA.

Class IV. Ord. V. DIAPHORETICA.

Class IV. Ord. VI. DIURETICA.

Chloroform, or Terchloride of Formyle, is a volatile liquid which is

analogous to Ether and Alcohol both in nature and medicinal action, but

very different in chemical construction.

Ether = C_{4}H_{5}, O.

Alcohol = C_{4}H_{5}, O+HO.

Chloroform = C_{2}H, Cl_{3}.

A solution of Chloroform in spirit, sold under the names _Terchloride of

Carbon_ and _Chloric ether_, is in very general use, and is employed in

very much the same cases as Nitric ether, being in the first place

stimulant, and subsequently anodyne, soporific, and diaphoretic.

Chloroform is physiologically an Inebriant. But it is for certain

peculiar actions that are coincident with, or immediately follow, this

production of inebriation, that it has been so widely and so

successfully employed in medicine since its recent discovery. Its two

important operations are its anæsthetic effect on sensory nerves, and

its paralyzing influence on muscle.

With regard first to the general selection of anæsthetic or anodyne

remedies, it is to be observed that there are four distinct kinds of

Pain, which differ very much in the treatment required. (1.) Firstly,

there is _inflammatory_ pain, caused by an active disease. It is

aggravated by pressure; and it has a local cause. For this Opium is the

best Neurotic remedy, but it should not be used without an attempt being

previously or at the same time made to subdue the active inflammation.

(2.) _Irritative_ pain is different. It depends merely on nervous

irritation. It also has a local origin; but it is relieved, instead of

being aggravated, by a pressure or friction. Such is the pain produced

by lead-colic, or by the passage of a gallstone or renal calculus. The

pain of Neuralgia is generally of the irritative kind. So is that of

Gastrodynia. So also the pain artificially inflicted by the knife in

surgical operations. For irritative pain on the surface Aconite is most

efficacious. Belladonna comes next to it. In Gastrodynia Hydrocyanic

Acid is to be preferred. But to counteract the pain of a surgical

operation we require a medicine which shall be capable of producing a

powerful effect on the whole system at once. Such medicines are Ether

and Chloroform. It is found most convenient to bring the patient under

their influence by causing him to inhale the vapour into his lungs.

Being absorbed by the pulmonary mucous surface, and passing directly

into the circulation, the medicine thus takes effect rapidly. There is

no time for the volatile liquid to be excreted from the blood, so that

the ulterior effect of the anæsthetic cannot be escaped. The third and

most important advantage of this mode of administering Chloroform is

that by it we are enabled to regulate with exactness the degree of its

action, which is a dangerous one, and to stop it when it has gone far

enough. When introduced by inhalation into the general circulation,

Chloroform acts upon the brain and sensory nerves throughout the body,

so as completely to extinguish their natural sensibility. It is thus an

agent of immense value where we wish to save the patient from an extreme

and agonizing degree of irritative pain, whether to be caused by the

edge of a cutting instrument, or by the throes of parturition. But it

also acts as an anæsthetic when applied locally, as to a painful ulcer,

or a hollow tooth-stump. (3.) The third kind of pain is _reflex_ in its

origin; as the pain in the knee in Hip-joint disease. We should do no

good if we troubled ourselves to combat the local symptom in such a

case; we should rather direct our attention to that condition which is

the distant cause of the pain. (4.) A fourth kind of pain may be called

_eccentric_. Like the last, it does not originate in the painful part.

It has its origin in the brain or nervous centres. Of such a kind are

the various pains of Hysteria. Local anæsthetics are here worse than

useless. The brain disorder must, if possible, be remedied.

Chloroform is better adapted for inhalation than Ether, because it is

considerably less irritating. It is, on the whole, very safe, when

proper care is taken. And yet it cannot be denied that sudden deaths

_have_ occurred from the use of Chloroform, which could not have been

avoided by any known precautions. Such an admission tells little against

the remedy; for supposing the proportion of deaths from inhalation to be

about 1 in 10,000, it must be confessed that it is better that one out

of that number should die of the Chloroform than that 100 should die of

fright. Out of 9000 cases of its inhalation at St. Bartholomew's

Hospital it is reported that not one died of the anæsthetic.

The stages of the action of Chloroform when inhaled may be briefly

stated as follows: _1st stage_: some alteration in the feelings of the

patient; _2d stage_: inebriation; the mind and volition are impaired;

consciousness remains; _3d stage_: unconsciousness; anæsthesia.[48] The

loss of sensibility may even occur in the second stage, the patient

remaining conscious. The inhalation should not be prolonged beyond the

occurrence of the third stage. The pulse is still full. There may be

muscular movements, or even cries. In the next stage there is stertorous

breathing; the eyelids no longer contract when touched with the finger;

the pulse is felt to falter. This is dangerous. To this succeed stoppage

of the heart and respiration;--death.

There are four rules which it is safe to follow in the administration

of Chloroform; not to go on when there is stertorous breathing; not to

administer it when there exists any serious disease of the heart or

lungs; not to undertake under its influence an extensive operation on

the mouth or jaws; and so to arrange the process as that the vapour

shall be freely diluted with air. If the third rule be neglected, the

blood may flow into the windpipe and cause suffocation, for the patient

is deprived of the power of swallowing. The dilution with air is

necessary, not only to moderate the action of the remedy, but that the

necessary vital function of respiration may not be interfered with. It

is also well known that it is convenient to administer Chloroform on an

empty stomach, or it will be likely to produce vomiting.

Though Chloroform rarely fails to annihilate pain, and thus greatly to

diminish the terror of the patient, it will not prevent him from

sometimes dying of the shock of a serious operation. An extensive injury

to the body will suffice to produce a prejudicial effect upon the heart

and nervous system, which is independent of the feeling of pain, and may

occur without moral suffering.

Chloroform is employed by some to relieve the pain of parturition. It is

not found to interrupt the action of the uterus.

But, with this exception, it is a general muscular relaxer and

paralyzer, and may thus be inhaled before an attempt to reduce an old

dislocation, or to restore a hernia of long standing. It is more

efficient in such cases than either Opium or Tartar Emetic, and produces

less distress than the latter. For the same operation it is sometimes

employed in spasmodic disorders. It has even been known to arrest the

paroxysm of that most incurable of all disorders, Tetanus. I have known

it to do great service both in Epilepsy and in Hysteria, when ordered to

be inhaled regularly twice a day. It has been highly recommended by some

who have tried it in Delirium tremens. (_Vide_ p. 237.)

OPIUM.

Class II. Div. II. Ord. II. NARCOTICA SOMNIFERA.

Class IV. Ord. V. DIAPHORETICA.

Opium is the chief member of the second division of Narcotics, which

consist of medicines that, in their action on the heart, are about

intermediate between Stimulants and Sedatives, and in their secondary

action, on the intellectual functions produce in them, the condition of

sleep (p. 239.) Opium produces at first some stimulation, and

exhilaration of the mind, with a full pulse, and general febrile

excitement. This soon subsides, and is succeeded by drowsiness and

sleep. Large doses cause slowness of the pulse, slow and difficult

breathing, and coma. If a small dose of Opium be continually repeated,

the stimulant action may be maintained for a time, and the Narcotic

effect prevented. But whenever it is taken habitually, the dose will

require to be gradually increased, or the desired effect will not be

produced, for the system is induced by degrees to tolerate the remedy in

larger and larger quantities. Given in moderate doses, it powerfully

relieves pain, and controls nervous irritability. Though it always tends

to produce sleep, its anodyne effect may take place without its

soporific action.

It is useful in the painful inflammations of the serous and mucous

membranes. But it tends to cause congestion of the brain. It should thus

be generally avoided in brain-disorders; and, on account of its primary

stimulant action, it should only be very cautiously used, or altogether

avoided in cases of high fever, where there is a hot dry skin, or a full

and hard pulse. The system may sometimes be prepared for it by

antiphlogistic treatment; or Tartar Emetic or Ipecacuanha may be

conjoined with the dose of Opium. Ipecacuanha and Opium are combined in

Dover's powder.

Opium is a Diaphoretic; but it diminishes all the other secretions, and

most especially that of the bowels. In the treatment of fevers and

inflammations it is often combined with Calomel, for the purpose of

preventing the latter from passing out by the bowels, and of allaying at

the same time the nervous excitement and pain.

Whether any precise connexion may exist between these various actions of

Opium, is a difficult thing to determine. It is certain that there are

other Narcotics and Sedatives which are able to relieve pain, but which

neither cause constipation, nor produce cerebral congestion. Purgative

medicines, which open the bowels and diminish cerebral congestion, are

so far opposed to Opium. Those effete matters which it is the function

of the bowels to excrete from the blood, and whose excretion is promoted

by purgative medicines, have an action on the brain which in some degree

resembles that of Opium. Constipation produces drowsiness, and torpor of

the mental faculties. And it is worthy of remark that Opium does not

seem to produce quite its proper effect when combined with a medicine

which causes purging. Thus it is barely possible that the action of

Opium in causing congestion of the brain may be in part referrible to

the influence of those excrementitious matters which it hinders from

passing out through the intestinal glands (p. 291.) But nothing

conclusive is known on the subject.

How, we may ask in the next place, does Opium produce constipation? It

has none of the characters of a general Astringent, and yet there is no

Astringent like it in its action on the bowels. An attempt has been made

to explain it on mechanical grounds. Poisseuille some time ago asserted

that a solution of Morphia prevented the process of endosmosis through a

dead animal membrane. Matteucci and others account for the operation of

Opium on this principle, supposing that by exerting this action on the

living mucous membrane, it is able to prevent the transudation of fluids

from the blood into the cavity of the bowel. But this view seems even

at first sight unsatisfactory. If such a force is really exerted, and

the passage of fluids through a membrane prevented by the action of

Opium, must it not apply to the stomach as well as to the bowel? Why is

Morphia absorbed at all? It should stop the digestive process

altogether. And why is the secretion of the skin increased by Opium,

while that of the bowels is suppressed? (_Vide_ Matteucci's _Lectures_,

p. 74.)

But there is reason to suppose that a serious error of observation has

been made by those who first asserted that a solution of Morphia tended

to arrest the process of endosmosis. Dr. Cogswell has lately made some

careful experiments on the subject, and he finds that a solution of

Muriate of Morphia passes readily through the bladder of an endosmometer

to serum or a heavy saline solution. And when experiments are made on

two other liquids of different density, the addition of Morphia to one

or other of them is found to effect no alteration in the direction or

rapidity of the current.

Opium is a general paralyzer to muscular fibre, both of the voluntary

and involuntary kind, but particularly of the latter. And the only

reasonable attempt that can be made to explain the action of Opium in

producing constipation, is by a reference to this its paralyzing

influence on the coat of the bowel, taken in conjunction with the torpid

condition of the general system, and suspension of the animal functions,

produced by the secondary action of this Narcotic on the nervous forces.

A considerable dose of Opium produces contraction of the pupil of the

eye. A larger dose causes coma. The Deliriant Narcotics, _i.e._

Hyoscyamus, Belladonna, and Stramonium, dilate the pupil, and in large

doses cause delirium. Their action is thus readily distinguished in

cases of poisoning.

Opium is the best internal remedy in all cases of pain and nervous

irritation, except where contraindicated by great febrile excitement, by

stomach irritation, or by cerebral congestion. It acts powerfully on

children, and should be administered to them very cautiously, or not at

all. It is given to lessen the secretion in some cases of diarrh[oe]a.

It is generally unadvisable to give it when there is constipation or

hepatic congestion. In wakefulness, mania, and delirium, when unattended

with congestion of the brain or fever, it is highly serviceable. In

spasmodic disorders, convulsions, and cough, it is more or less

applicable.

That the active principles of Opium are absorbed, and pass into the

blood, has been proved by their detection in the urine. (p. 223.) It

does not act on the system before time has been allowed for this

absorption. If taken by a mother during suckling, it may act upon the

infant by passing into the secretion of milk. It acts upon the nervous

system, and probably on the muscles also (_see note_, p. 224,) through

the medium of the blood.

As a Diaphoretic in fevers and inflammations, Opium is to be preferred

in cases where the skin is already moist and cool, where the pulse is

soft, and the tongue not coated. But where there is febrile excitement,

Antimony, or Ipecacuanha, is rather indicated. Opium may act on the

glands of the skin as a true Eliminative; or it may possibly operate in

the same indirect way as a nauseant dose of Tartar Emetic, relaxing the

ducts of the sudorific glands by its paralyzing influence on their

muscular fibre.

The chemical construction of Opium is a matter of considerable interest.

Morphia, the chief active principle, is an alkaloid which is almost

identical with Opium in its narcotic actions but slightly more sedative.

Unencumbered by inert matters, it presents us with an anodyne in a more

concentrated form. But the combination of the Morphia with other

principles in the crude Opium is worthy of remark. Both Morphia and

Opium are liable occasionally to produce nausea, headache, loss of

appetite, and depression of the spirits. There are various ways in

which we may try to obviate these unpleasant symptoms. To prevent

nausea, we may combine the dose with an aromatic. Dr. Copland has

successfully combined Morphia with an aromatic spirit, in cases where

alone it was apt to bring on hypochondriasis. And to prevent the loss of

appetite in Delirium tremens, Dr. Todd recommends to combine Morphia or

Opium with Quinine or some other Tonic. But it is very curious that in

the construction of Opium an attempt is made by nature at the very

things that we so much desire in practice. For the drug contains, in

addition to Morphia, an aromatic volatile oil, and a neutral principle,

wrongly called Narcotine, which has been proved by some experiments made

in India to be a simple Tonic, like Quinine. So that if we could only

separate from the other parts of the drug the Morphia, volatile oil, and

Tonic principle, we should obtain an admirable combination made ready to

our hand. But Opium contains also other matters which are mere

incumbrances, but which are more or less taken up by the various liquid

menstrua that we employ; as, an irritant resin; other neutral

principles, as narceine, Meconine, and Papaverine,--and Meconic

acid,--all of which are probably inert; and, what is worst of all, a

small quantity of an alkaloid called Thebaia, said by Magendie to have

an action identical with that of Strychnia.

Though Morphia constitutes only about twelve per cent. of the best

Opium, the dose of it required is at least one fourth of that of the

latter. It seems therefore that Opium must contain some other narcotic

principle. Codeia is a Narcotic, of less power than Morphia, and though

it is contained in Opium, it is scarcely in sufficient quantity to

explain the strength of the drug. It is likely that Opium contains more

than one volatile oil, and that the odorous principle to which its

peculiar smell is owing is itself narcotic in its action. A parallel

case to this is verified in the instance of bitter almonds, which not

only yield Hydrocyanic acid, the most powerful Sedative known, but

contain a large quantity of a volatile oil, which remarkably resembles

the acid in its poisonous action. (_Vide_ pp. 238, 268.)

HYDROCYANIC ACID.

Class II. Div. III. ORD. I. SEDANTIA GENERALIA.

Hydrocyanic or prussic acid (C_{2} N, H,) a very volatile liquid,

soluble in water, is one of those mysterious vegetable compounds which,

containing no chemical element that is not also contained in animal

structure, are yet gifted with a wonderful power over the vital forces.

One drop of the pure acid is sufficient to cause death. But the

officinal acid is an aqueous solution, containing only 2 per cent. of

the other.

It is a powerful Sedative to the nerves generally. Its action is direct,

and is not preceded by any primary stimulation. Diminishing sensibility,

it is therefore used as an anodyne. Controlling muscular action, it is

employed as an anti-spasmodic. But it appears especially to influence

the reflex nervous actions. It is therefore of especial use in the

paroxysmal coughs of Hooping-cough and of Phthisis, which have a reflex

origin in the irritation of the mucous membrane. It acts on nerves as

well as on nerve-centres. Thus it is particularly useful in neuralgic

forms of Gastrodynia; and it seems to allay the pain in the stomach by

diffusing itself directly it reaches it, so passing through the mucous

membrane at all points, and coming in contact every where with the

irritated sensory nerves. It is sometimes useful in cases of vomiting,

or pyrosis.

If applied to the surface of the skin, it numbs the superficial nerves;

but on account of its rapid volatility, and the dangerous results that

would follow the inhalation of its vapour, it is not appropriate as an

external anaesthetic.

A poisonous dose produces first convulsions of the whole frame, then

syncope, and death. Strychnia produces convulsions, but they are not

caused in the same way as those of Hydrocyanic acid. For the two

medicines are obviously opposed in their action, Strychnia being an

exalter of sensation and of reflex action, and Hydrocyanic acid a

depresser of the same. The convulsion caused by Strychnia is tonic; that

by Hydrocyanic acid, asthenic. The one, being a special Stimulant,

causes convulsions by an excitement of the spinal cord; the other, being

a Sedative, does it by deranging the function of that centre. (_Vide_

pp. 245, 243.)

ACONITE.

Class II. Div. III. Ord. I. SEDANTIA GENERALIA.

This medicine, like the last, is a powerful General Sedative, and a

dangerous poison. It depresses the influence of the brain, and paralyzes

all the nervous functions. It tends at length to kill by producing

syncope.

It acts especially on the superficial sensory nerves, and tends to

extinguish feeling and pain. It is the best external anæsthetic with

which we are acquainted. It is thus eminently useful in the treatment of

that most painful of all disorders, Tic douloureux, or irritative

Neuralgia of the face. When Quinine and all internal remedies have

failed, the tincture of Aconite, or an ointment containing the alkaloid,

will in most cases, if applied to the part, effectually relieve the

pain. It is applicable in local irritative pain at any part of the

surface, as in Sciatica, Lumbago, or a Scirrhus of the breast that has

not opened. But, like the other local anæsthetics, it is of little

service in cases of inflammatory pain, for this, when local, depends

upon an active cause, and would be liable to be increased by the rubbing

required in the application of the Aconite. When the remedy takes

effect, some heat is first experienced at the part; there is then

tingling; and lastly, complete numbness, and a sensation of cold, which

endure for some time. No visible change is effected.

Aconite subdues the action of the heart. Dr. Fleming has therefore

recommended small doses internally in cases of acute rheumatism. But

considerable care is required in the internal employment of the drug, on

account not only of its dangerous properties, but of the great variety

in strength which exists among the preparations that are usually

employed. The difficulty experienced in the preparation of the alkaloid

Aconitina, which is the active principle of the plant, and the very high

price at which that substance is usually sold, have prevented it from

being so extensively employed in practice as its medicinal properties

would appear to deserve for it. On account of its cleanliness as an

outward application, and the certainty and uniformity of its sedative

and anæsthetic actions, the pure alkaloid is far preferable as a

medicine to Aconite itself, and is adapted for all the cases in which

the latter has been employed.

Having some time ago been successful in an attempt to discover a mode of

preparing Aconitina,[49] I have made some experiments with it on various

small animals, for the purpose of ascertaining its power, and the

symptoms of its action. It is a very active poison. Proceeding upwards

in the animal scale, I find that 1/300th of a grain, in solution in

water, suffices to kill a mouse. 1/100th kills a small bird after a few

minutes; 1/50th almost instantaneously. 1/20th of a grain has killed a

cat. 1/10th invariably proves fatal to the unfortunate feline in the

course of twenty minutes or half an hour.

Calculating as well as I can from these data, I consider that 1/10th of

a grain of this alkaloid would be sufficient to cause the death of an

adult man. During the action of the poison on cats the following

succession of symptoms is generally observed. They will illustrate in

most of its phases the action of a Sedative medicine.

1. An increased flow of the salivary secretion. (_Vide_ p. 282.)

2. Vomiting.

3. Delirium, with hallucinations. Impairment of volition; apparent loss

of sensation.

4. Convulsions; paralysis.

5. Breathing difficult and gasping,--gradually ceasing.

6. Death; pupils of the eye are seen to be dilated.

Aconitina has thus a powerful action on the brain, and on the nerves

generally. The flow of saliva seems partly to arise from a paralysis of

the fauces. The animal makes ineffectual attempts to swallow, and

breathes spasmodically. By a small dose the anæsthesia would probably be

produced, without the other effects. On examination of the body after

death the lungs are found to be healthy, but shrunken and bloodless; the

trachea contains much frothy mucus, which may possibly have flowed into

it on account of the palsy of the glottis; the cavities of the heart are

full; the mucous membrane of the stomach pale. It seems then that the

immediate cause of death is paralytic syncope,--a loss of power in the

heart. As the mucous coat of the stomach evinces no trace of congestion,

it is probable that the vomiting is not caused by irritation, but by a

sedative or deranging action on the function of the Vagus nerve. (_Vide_

pp. 242, 245.)

DIGITALIS.

Class II. Div. III. Ord. II. SEDANTIA SPECIFICA.

Class IV. Ord. VI. DIURETICA.

This important medicine has already been prominently noticed as one of

the agents that exert a special sedative and deranging power over the

functions of the Vagus nerve. It will only be necessary now to sum up

shortly the details of its action.

It does not depress nervous force generally. It has no action on the

brain, except as connected with the Vagus nerve. Neither does it affect

the spinal cord, or the nerves of sensation or motion. Its most obvious

action in small doses is to depress the force of the heart. It sometimes

quickens the pulse, but always weakens it, and reduces its rate in the

end. It therefore supplies us with a ready means of weakening the heart,

whenever we desire to do this. In cases of hypertrophy, where the heart

is too strong,--or in aortic aneurism, or active hemorrhage, where a

forcible beat would be dangerous,--Digitalis may be used for this

purpose. But it is especially useful in dropsies; for by its action on

the heart, it diminishes congestion of the venous system, and by thus

removing the pressure from the veins, it favours the absorption of the

fluids effused. It should, however, be avoided in cases where there is

very serious cardiac obstruction, or where the heart is habitually weak,

and there is a natural liability to syncope. For the tendency of the

medicine is to cause death by producing syncope.

Certain precautions are necessary in its administration. The patient

should be generally confined to the recumbent posture; for if, while

under the influence of Digitalis, he should suddenly rise, and the

heart, already weakened, have further to contend with the force of

gravity in the propulsion of the blood upwards, it may actually stop.

The dose also should be cautiously regulated, and, if it do not operate

at once, it must not be increased, or too soon repeated; for this

medicine is apt sometimes to accumulate in the blood, and though several

doses may perhaps be given without effect, they are afterwards liable at

any time to be suddenly discharged upon the nervous system, and may then

produce by their united action a dangerous result.

A considerable dose of Digitalis, as of Tartar Emetic, deranges the

control of the Vagus nerve over the function of the stomach, and may in

this way produce nausea and vomiting. There is no reason for supposing

that it irritates the coat of the stomach. (_Vide_ p. 93.)

The active principle of Digitalis is secreted from the system in the

urine, and probably acts as a true Eliminative Diuretic. But it tends

more powerfully to promote diuresis in another indirect way. Any thing

which diminishes the pressure on the vascular system, as Digitalis, by

weakening the force of the heart, tends thereby to promote absorption,

and to increase the secretion of urine.

So that the employment of Digitalis in Dropsy is attended with a twofold

advantage; by its cardiac action, it prevents a renewal of the dropsical

effusion; by its diuretic power, it causes a quantity of fluid to be

drained out of the system through the kidneys. That it may do this the

more effectually, it is generally considered advisable to combine it

with other diuretics. (_Vide_ pp. 251, 304, 308.)

TANNIC ACID.

Class III. Ord. II. ASTRINGENTIA VEGETABILIA.

This is the chief astringent principle of vegetables. It is very soluble

in water, crystallizable, and has a strong astringent taste. It is not

possessed of those marked properties that are vulgarly attributed to

acids; but its solution reddens litmus-paper, and it combines with bases

to form salts.

When received into the stomach, it is absorbed, and passes in the

circulation to distant parts. Its action consists in a power of causing

the contraction of muscular fibre when in contact with it; and this

power appears to depend mainly upon a chemical property that it

possesses of coagulating albumen and analogous compounds. Capillary

vessels, and the small ducts of glands, contain in their walls certain

fibres of unstriped muscle; and Tannic Acid, by causing this muscle to

contract, is able to diminish the caliber of these tubes, and thus to

moderate or arrest the flow of blood in the vessel, or to lessen the

amount of the excretion of the gland. Thus, in all cases of hæmorrhage

from the small vessels, or of inordinate secretion from any glandular

organ, Tannic acid is appropriate. It is the best and safest of all

Astringents for internal use, excepting only Gallic acid.

I have already stated as worthy of remark the fact that Gallic acid is

of little or no use as an Astringent when applied to external parts.

Given internally, it is very efficacious. From this alone it would seem

that there must be something in the blood which enables it to take

effect. Reasons have also been alleged for supposing that Tannic acid is

not a simple substance. When it is taken into the system, Gallic acid is

secreted in the urine; and it appears that Tannic must actually consist

of Gallic acid combined with certain other elements, or with some other

definite substance; and that the astringent property which is so

valuable is confined to the compound body thus produced. Gallic acid

alone has not the power of precipitating albumen.

What then is this other substance? It must be something which is

contained in or formed in the blood, which added to Gallic, will be

capable of forming Tannic acid; and which, when united to it, will

enable Gallic acid to precipitate Albumen. These various requirements

are fulfilled by the group of elements that constitutes grape-sugar

(C_{12}H_{12}O_{12}.) This compound is continually forming in the blood

during the blood-processes that are connected with respiration. It has

been observed that a solution of gum (C_{12}H_{11}O_{11},) added to one

of Gallic acid, will enable the latter to coagulate Albumen. And the

elements of Tannic acid may be constructed out of those of Gallic acid

and grape-sugar.

Tannic acid = C_{18}H_{6}O_{10} + 2 aq.

Gallic acid = C_{7}HO_{3} + 2 aq.

Three equivalents of anhydrous Tannic acid amount to six of Gallic acid

and one of grape-sugar.

3(C_{18}H_{6}O_{10}) = 6(C_{7}HO_{3}) + C_{12}H_{12}O_{12}.

So that it is very probable that when Gallic acid is taken into the

blood, it acts as an Astringent by co-operating or uniting with the

elements of grape-sugar in that fluid. But when Tannic acid is received

into the organism, and has done its work there, it is finally

decomposed, Gallic acid passing out into the secretions, and the sugar

being retained in the body for combustion into carbonic acid and water.

(p. 116.)

The principal vegetable substances that are employed as Astringents are

said to contain Tannic acid in the following proportions:--

Kino 70 per cent.

Krameria 43 "

Catechu 40 "

Uvæ Ursi 36 "

Oak-galls 26 "

Pomegranate-bark 19 "

Tormentil 18 "

Oak-bark 16 "

These numbers are a tolerably fair measure of the astringent power of

the substances named. But it must not be supposed that the astringent

principle is in all cases strictly identical with Tannic acid, properly

so called; for there appear to be various modifications of this

substance contained in the different plants, many of which have peculiar

chemical characters of their own, but all of which agree in possessing

the power of tanning, or combining with animal gelatine, and in the

medicinal property of astringency.

GENERAL INDEX.

Absorption, action of medicines by, 61, 68, 87.

Acids, 120.

Aconite, 352.

Aconitina, symptoms of action of, 353.

Ague, remedies used for, 129, 207.

Alcohol, 339.

Aliments, 115.

Alkalies, 126.

Aloes, absorption and action of, 80, 96, 289.

Alteratives, 35, 157, 165.

Alum, as an Astringent, 263.

Ammonia, 334.

Anæmia, treatment of, 148, 320.

Anthelmintics, 97.

Antidotes, action of, 92.

Antimony, 321.

Arsenic, 333.

Astringents, 256, 358.

Belladonna, 240.

Benzoic acid in lithic deposits, 156.

Bile, relation of remedies to the, 137.

Billing, Dr., on action of medicines, 132, 163, 216.

Bismuth, nitrate of, 87, 94, 97.

Blood, medicinal actions in the, 103, 106, 167.

Borax, actions of, 155, 232.

Brodie, Sir B., his experiments, 63.

Calomel, not a sedative, 328.

Cantharides, its uses, 67, 214, 307.

Castor oil, 291.

Catechu, 358.

Cathartics, 95, 286.

Chalk, not astringent, 264.

Charcoal, said to become absorbed, 88.

Chemical theories of medicinal actions, 47.

Chlorine, an Antiscrofulic, 193.

Chloroform, 342.

Cholagogues, 295.

Cinchona, 129.

Citric acid, its actions, 123, 202, 205.

Cod-liver oil, 310.

Colchicum, 331.

Conium, its actions, 246.

Copaiba, action of, 267.

Copper, Sulphate of, 93, 211, 264.

Counter-irritants, action of, 67, 91.

Creosote, actions of, 94, 245, 265.

Diabetes, treatment of, 119, 194.

Diaphoretics, 298.

Diarrh[oe]a, treatment of, 294.

Diet, rules of, 118.

Digestion of medicines, 68-86, 104.

Digitalis, 364.

Diuretics, 302.

Duncan, Dr., his classification, 34.

Dropsy, treatment of, 307, 355.

Eberle, his arrangement of medicines, 39.

Elaterium, its modes of action, 85, 289.

Eliminatives, 268.

Emetics, 92, 324.

Emmenagogues, 102, 275.

Endosmosis, passage of medicines by, 71.

Epilepsy, remedies used in, 211, 229, 337, 345.

Ergot of Rye, 233.

Ether, 343.

Evacuants, action of, 55, 269, 280.

Expectorants, 283.

Fermentations in the blood, 180.

Fevers, treatment of, 124, 185, 188, 302.

Gallic acid, 265, 357.

Gold, its use in Syphilis, 189.

Gout, treatment of, 194, 331.

Grape-sugar in the blood, 116, 198.

Hæmatosin, relation of to Iron, 145.

Hæmorrhage, treatment of, 263.

Hom[oe]opathy, fallacies of, 53, 184.

Hydrocyanic acid, 351.

Hyoscyamus, 240.

Hysteria, remedies used in, 211, 232, 337.

Inflammations, treatment of, 185, 323, 325.

Iodide of Potassium, 188, 191, 328.

Iodine, 328.

Ipecacuanha, actions of, 249, 283, 295, 298.

Iron, 145, 319.

Jalap, absorption and action of, 85, 96, 289.

Lactic acid in the system, 69, 116, 198.

Laxatives, 287.

Lead, actions of, 211, 254, 263.

Lemon-juice, uses of, 202, 205.

Local access, rule of, 98.

Magendie, M., his experiments, 63.

Masticatories, 281.

Mechanical theories of medicinal actions, 43, 219.

Mercury, 325.

Morphia, modus operandi of, 220, 347.

Murray, Dr., his classification, 36.

Narcotics, 234.

Nitric acid, its uses, 120, 196.

Nitrohydrochloric acid in Oxaluria, 196.

Nux vomica, 337.

[OE]sterlen, Prof., on absorption of medicines, 88.

Oils, fixed, absorption and action of, 84, 278, 288.

Oils, volatile, their actions, 227, 267, 278.

Opium, 346.

Pain, treatment of, 342.

Pereira, Dr., on action of medicines, 40, 131, 162, 228.

Phosphoric acid, not astringent, 262.

Phosphorus, its actions, 229, 311.

Pitch, used in Lepra, 214.

Potash, 315.

Purgatives, 286.

Quinine, 317.

Refrigerants, chemical theory of, 123.

Resins, absorption and action of, 83, 279, 288.

Rheumatism, remedies used in, 194.

Rhubarb, action of, 294.

Salines, absorption and mode of action of, 74, 188, 289, 300.

Salt, common, its actions, 93, 193, 210.

Sarsaparilla in Syphilis, 190.

Scammony, absorption and action of, 85, 96, 289.

Schultz, classification of, 57.

Scrofula, treatment of, 191.

Scurvy, remedies used in, 205.

Sedatives, 242.

Senna, chemical nature and action, 279, 289.

Sialagogues, 281.

Silver, nitrate of, its actions, 211, 264.

Skin diseases, treatment of, 213.

Special Sedatives, 249.

Special Stimulants, 233.

Squill, its doubtful action, 253.

Starch, digestion of, 82, 116, 197.

Stimulants, 226.

Stramonium, 240.

Strychnia, 337.

Sulphur, in skin diseases, 215, 301.

Sulphuric acid, 313.

Syphilis, treatment of, 188.

Tannic acid, 356.

Tartar emetic, 321.

Tea, a Sedative, 248.

Thomson, Dr. A. T., on action of medicines, 39.

Tonics, 129.

Turpentine, its modes of action, 229, 267, 305.

Urinary deposits, treatment of, 149, 307.

Water, its elimination, 154, 300, 307.

Young, Dr., his classification, 32.

Zinc, sulphate of, its actions, 93, 211, 264.

FOOTNOTES:

[1] "In reasoning as to the probable effects of particular

remedies on the human body, the conditions and circumstances of the

latter are so various in different cases, and the number of concomitants

which have to be considered in addition to the more obvious facts and

symptoms, is so great that the utmost exertion of human sagacity,

founded upon the largest induction of particulars which any one mind is

capable of embracing and retaining, can do no more than approximate to

that real evidence of which the case seems by its proper nature to be

susceptible."--_Glassford's Principles of Evidence._

[2] Dr. A. Pitcairn, in 1704, concluded one of his works by

saying, "Thus have I succeeded in solving the noble problem, viz., to

find a remedy for a given disease. _Jamque opus exegi._"

[3] "In the mean time it may suffice for the physician to know

the effects of a medicine when applied to the body, though he knows not

the particular manner whereby it acts."--_Van Sweiten's Commentaries on

Boerhaave_, vol. i. p. 394.

[4] "Every branch of study which can at all claim the character

of a science requires two things: 1. A correct ascertainment of the data

from which we are to reason; and 2. Correctness in the process of

deducing conclusions from them."--_Whateley's Elements of Logic._

[5] There is no doubt that the small veins which ramify outside

the coats of the stomach and intestines are capable of taking up any

matters in a state of proper solution, even fats when dissolved in

alkali. But are medicines ever taken up by the lacteal absorbents?

Probably seldom or never; for it seems that these vessels are only

engaged after a full meal, and subsequent to the regular formation of

chyle. They do not exist in the coat of the stomach, but commence in the

small intestine at some distance from the pylorus.

[6] It may be of some use if I adduce here a characteristic

example of each of the great groups of medicines to which I have alluded

above:

CLASS I. _Hæmatics._

Div. 1. Restoratives. Iron, in Anæmia.

Div. 2. Catalytics. Mercury, in Syphilis.

CLASS II. _Neurotics._

Div. 1. Stimulants. Ammonia.

Div. 2. Narcotics. Opium.

Div. 3. Sedatives. Hydrocyanic Acid.

CLASS III. _Astringents._ Tannic Acid.

CLASS IV. _Eliminatives._ Cantharides, and Croton Oil.

[7] The whimsical "_doctrine of signatures_" which prevailed in

the middle ages, and had its origin from very remote times, serves at

least to show that the local tendencies of medicines have always been

more or less recognised. So slight an experience is sufficient to

demonstrate their existence, that it could indeed hardly be otherwise.

It was oddly supposed that every natural substance bore evidence in its

outward form or physical peculiarities of the part of the system over

which it exerted a curative power.

[8] "He was one of the first who, leaving the old conjectural

method of physical writers, struck into a new and more solid way of

reasoning, grounded upon observations and mathematical principles."--

_Preface to Dr. Pitcairn's Works: 1715_.

[9] "A Treatise of Diseases in General, wherein the true

causes, natures, and essences of all the principal diseases incident to

the human body, are mechanically accounted for and explained, and their

respective intentions of cure assigned upon the same principles," vol.

ii. p. 813, 820.

[10] "Medical Precepts and Cautions," page 294.

[11] "If there be any bodies--suppose gold and silver--out of

which all these principles cannot be drawn, let not the artist think

that it is because they are not therein contained. No! it is because

that God has so firmly united them against the possibility of our

separation."--P. 809.

[12] Dr. Pitcairn's Works, 1715, p. 219.

[13] I have omitted here to make mention of the doctrine of

infinitesimal doses, not only because it is out of my province, but

because it is really too unreasonable to be even discussed. When it is

said that the decillionth of a grain--the ordinary dose among these

practitioners--is expressed by a fraction, the denominator of which is a

unit followed by sixty ciphers, this statement will be surely enough for

any man who is at all acquainted with figures. I do not conceive it

possible that matter is _divisible_ to any thing like this extent.

[14] Sydenham's Works, translated from the Latin by Dr. Swan.

5th edition, 1769, p. 1.

[15] Preface to the same, p. 22.

[16] "First Lines of the Practice of Physic." Fourth edition,

1784. Vol. i. p. 126 et seq.

[17] An exception should be made here of certain animal

poisons, such as the venom of serpents, which, though they act on the

system when introduced directly into the blood, seems to be rendered

innocuous by the action of the stomach, which probably decomposes them.

[18] Physiological Researches, p. 63-67.

[19] It should be mentioned that Sir Benjamin Brodie, though

admitting the force of the above experiments, and deriving from them

very similar inferences, yet considers it likely that the action of a

medicine or poison may be _partly_ propagated by means of the nervous

system. _Op. cit._ p. 127.

[20] _Vide_ Paper in Medical Gazette, June 18th, 1841.

[21] Todd and Bowman's Physiology, vol. ii. p. 280.

[22] _Vide_ Pereira's Materia Medica, vol. i. pp. 101, 106.

[23] Such is the case in health, when the muscular pressure of

the intestine must exceed the pressure on the vascular system on the

other side. This latter pressure, when increased, tends to stop or to

reverse the inward current. Thus plethora and fever, diseased

conditions, counteract absorption by causing pressure on the coats of

these capillary vessels. Bleeding,--a drain of fluid caused by an

increased secretion,--or such agents as Tartar Emetic and

Ipecacuanha,--diminish this pressure by weakening the force of the

heart, and thus favour natural absorption.

[24] It is stated by Dr. Carpenter, that if a ligature be

applied below the pylorus of an animal, and Sulphate of Magnesia then

introduced into the stomach, purging is produced. This could only be by

the absorption of the salt, and its subsequent action from within on the

mucous membrane of the bowel below the ligature. This experiment is

unauthenticated, but if verified would certainly be most conclusive in

favour of the view adopted above.

[25] Hydrochloric acid would probably precipitate medicinal

solutions containing silver, and thus render this substance inert when

given internally. Another therapeutic argument against this, as the acid

of the gastric secretion, may be drawn from the fact that the action of

calomel is very different from that of bichloride of mercury,--whereas

this acid would convert the former into the latter.

[26] Liebig (_Animal Chemistry_, Part I. p. 76) states that the

Bile contains Carbonate of Soda. The assertion that the Pancreatic juice

is alkaline must be rested mainly on the authority of M. Bernard.

[27] Occasionally, as in certain cases of Pyrosis, slight

vomiting may take place without any straining effort of this kind, but

apparently from the contraction of the stomach alone.

[28] Pereira's Materia Medica, 2d edit., vol. ii. pp. 1496,

1507, and elsewhere.

[29] Irritant Cathartics, like irritant emetics, may sometimes

affect remote parts on the principle of counter-irritation. Some explain

in this way the use of purgatives in disorders of the brain, but there

are other reasons which serve to account for this still more

satisfactorily. (_Vide Chap. IV., Art. Purgatives._)

[30] The process of cure by _counter-irritation_ may be

ascribed to the _secondary_ action of some medicines. Such an operation

may take place at a distance from the part affected; but it is

attributable to a peculiar affection of the nervous system, and has no

necessary connexion with the primary or proper action of a medicine.

_Vide_ p. 67.

[31] The details of this arrangement are founded solely upon

the _therapeutic operation_ of medicines, as used to cure diseases, and

not in any way upon their _physiological action_ upon a healthy man.

Much unnecessary confusion, in works on Materia Medica, has arisen from

these two different matters being taken into account at the same time.

Food is the only restoration of wanting material needful to a healthy

man; neither is there in such a case any need or opportunity for the

counteraction of morbid agencies.

[32] Animal Chemistry, p. 20.

[33] Possibly some parts of the bile, besides the colouring

matter, are truly excrementitious. But part of it is needful in the

animal economy, as has been proved by experiment. M. Schwann found that

when the contents of the bile-duct in dogs were caused to discharge

themselves externally through a fistulous opening in the wall of the

abdomen, the animals quickly wasted away and died. In some cases of

jaundice, the constituents of the bile appear to be vicariously excreted

by the kidneys; and perhaps the great depression produced by that

disorder maybe partly accounted for by the impossibility of the

re-absorption into the blood of these substances, naturally formed by

the liver. Having passed into the urine, there is no provision to enable

them to return.

[34] He states that one equivalent of binoxalate of ammonia and

four of water contain together the same elements as an atom of Taurine.

(_Vide Simon's Animal Chemistry_, vol. i. p. 47. _Syd. Society._)

[35] A deposit of Oxalate of Lime occurs sometimes. It is seen

in minute octahedra; but is rarely in sufficient quantity to be

distinguished by chemical tests. It does not come within the influence

of Solvent medicines.

[36] Some suppose that this acid occurs in healthy urine is a

free state. It is more commonly thought to exist as Urate of Ammonia.

Lehmann states that it is found as Urate of Soda. Others imagine that it

is held in solution by means of Phosphate of Soda.

[37] This acid is ascribed by some to Urate of Ammonia, which

is to a small extent soluble in water. Others consider that it is due

both to this and to Phosphoric acid, which is the opinion of Dr. Prout

and Dr. G. Bird. Others attribute it to Lactic acid, which is stated by

Berzelius, Lehmann, and Simon, to exist in healthy urine. Some consider

the acid to consist in a Super-phosphate of Soda. Liebig supposes that

it is due to Uric acid, held in solution by the common Phosphate of

Soda. He also considers Hippuric acid to be an invariable ingredient in

healthy human urine.

[38] According to Simon it is 1.0125; Becquerel makes it 1.017;

Dr. Prout and Dr. Golding Bird, 1.020; Berzelius rates it still higher.

[39] "The state or condition of formation or decomposition of a

body, the state of change of place or motion in which its particles are,

exerts an influence on the particles of many other compounds, if in

contact with them. The latter are brought into the same state; their

elements are separated and newly arranged in a similar way, and acquire

the power of entering into combination, a power which they did not,

under similar circumstances, previously possess."--_Liebig's Animal

Chemistry_, vol. i. p. 194.

[40] Dr. Mead, in 1751, recommended the employment in Scrofula

of burnt sponge, and a pill containing "sublimed Mercury" and

precipitated Sulphuret of Antimony. Plummer's pill is often prescribed

in these cases at the present day.

[41] Among these, Dock, Sorrel, Wood-sorrel, and Stonecrop, may

be mentioned. Such herbs have been long employed, and recommended by

authority. Dr. Mead, in 1751, recommended Scurvy-grass, Lettuce, and

Brooklime. He also made particular mention of the _Herba Britannica_,

which seems to have been the great Dock, Rumex hydrolapathum. The same

physician appears to have anticipated some of the modern applications of

Lemon juice. He employed it in liver-diseases generally, among which he

included a number of dyspeptic and gouty disorders. He gave it in

six-drachm doses; and says that he employed also in similar cases

_saponaceous_ medicines, and rhubarb. These remedies, apparently

heterogeneous, were recognised then, as now, to be useful in the same

cases. For we have just seen that Lemon-juice, Alkalies, Cholagogues,

and Tonics, are all more or less applicable in diseases of the Arthritic

group.

[42] I have just said that Neurotic medicines influence those

functions which are attributed to the nervous system. Now there can be

no reasonable doubt that they actually influence the nerves. But it is

worth while to notice here the curious fact that the same agents have

been found to paralyze the irritable or contractile tissues of certain

vegetables. Professor Marcet of Geneva first noticed that the vapours of

Chloroform and Ether affected the leaf of the sensitive plant so as to

prevent it from contracting at the touch, but without at the same time

perceptibly injuring its structure. I have produced the same effect on a

species of Acacia, which naturally closes its leaves at the approach of

night. The leaf experimented on remained open, while the others closed.

After a certain time it recovered. Solutions of Morphia, Conia, and

other sedatives, have been found to produce the same result. Now the

existence in plants of nervous tissues is not usually admitted. How then

are we to explain the analogous action of these paralyzing Neurotics on

animals and vegetables? Possibly they may be capable of acting directly

on contractile or irritable tissues in both cases, without necessarily

influencing the nerves in order to produce paralysis.

[43] Turner's Chemistry, 7th edit., p. 995.

[44] I do not here mean to imply that the products of the

actions of all glands are destined for excretion. It is probable that

the bile and some other secretions are partly re-absorbed into the

blood. But we are now concerned only with the function of glands as

emunctories.

[45] No lists of the Eliminative orders will be given; for as

only a general outline of the mode of action of these medicines is

intended, a detailed enumeration of the remedies comprised in each order

would be a needless appropriation of space.

[46] It has been asserted by Dr. Murray that it is impossible

for Mercury to pass off in the urine, on account of the Phosphoric acid

contained in that secretion, which would precipitate the metal. But

Phosphoric acid is also contained in the blood; and Mercury has been

discovered in the urine.

[47] Reference is made at the end of each article to those

parts of the Essay in which the remedy has been mentioned before.

[48] See Pereira's "Materia Medica," vol. i. p. 204.

[49] See account of the mode of preparation, by the Author, in

the second edition of Dr. Royle's "Manual of Materia Medica."

Transcriber's Note

The oe ligature is represented by [oe]

Subscripts are introduced by an underscore, e.g. CO_{2}

Greek words have been transliterated, e.g. [Greek: kineô]

The apothecaries' symbol for the dram is represented by [dram]. When

followed by "j" the quantity is 1 dram; when followed by "ss" the

quantity is 1/2 dram. The apothecaries' dram is 3.8879346 grams.