than of increasing action; so that, in whatever other class we might be disposed to place them, we should undoubtedly be inclined to remove them from that of the stimulants.

We now enter on the permanent stimulants, beginning with the class of tonics. By tonics, are understood those substances whose primary operation is to give strength to the system.' This definition accords with the idea which is usually attached to the term tonic; and it will be found to embrace an extensive class of medicines, which seem connected together by a natural resemblance. We have, however, considerable doubts whether they are fully entitled to the denomination of stimulants. Strength and action, so far from being always proportionate, are sometimes, as it appears, even opposed to each other; that which increases action seems to diminish strength, and that which augments strength seems to decrease action. The effect of those substances which are the most decidedly stimulating is certainly not tonic; if therefore tonics in some instances appear to stimulate, is it not more reasonable to conjecture that this depends on some incidental circumstance, than on their possessing a direct power of producing action? Were we to indulge ourselves in speculating on this point, we should be disposed to attribute the virtues of tonics principally to their operation on the organs of digestion. In what way they affect this function we are unable to explain, until we are better acquainted with the nature of the function itself: but they seem to render the stomach capable of converting the substances which it receives, into the most proper state for the nourishment of the system, and hence to repair the waste which is it all times going forwards in every part of the animal fabric. With respect to the substances which Mr. Murray places in the class of tonics, we feel some difficulty, on every hypothesis, of admitting the claims of several of those which are derived from the mineral kingdom. Mercury gives strength to the system, we allow, by curing a disease which produces debility: but it does this by an immediate action on the disease, and therefore is not, from this circumstance, intitled to the denomi nation of tonic. The same remarks will apply to copper and arsenic; the former of which improves the strength of the system when it cures epilepsy, and the latter when it removes ague but it does not follow in either case that the primary operation is tonic.-The author has omitted to introduce silver, which certainly has a claim to be placed in the same rank with copper; the internal use of the argentum nitratum does not appear to be noticed in any part of the work.

If we found it difficult to admit tonics into the class of stimu lants, we have still stronger objection against arranging astringents

under

under this title. Before, however, we form any opinion respecting the nature of these medicines, we must determine what substances we propose to consider as astringents. If we refer to their supposed modus operandi, we shall include those only which condense the animal fibre: but, if we take into account the ultimate effect produced, we must receive all those which restrain profuse or morbid evacuations Mr. Murray appears to have been principally guided by the first consideration, though he has introduced into his list some substances of the latter description. Thus chalk is placed among the astringents, in consequence of its use in diarrhoea; yet he confesses that its action in this disease depends on the removal of acidity. It is certainly more scientific to place in this class those substances only which have a sensible effect in condensing or approximating the animal fibres; though the other method would have been more consistent with a system which professes to arrange substances according to their effects on the body.

Employing the term astringent, as the present author has done, in the restricted sense, although we observe an evident analogy between the operation of the different substances included in it, we confess ourselves to be much indoubt respecting the nature of their action. We agree with Mr. Murray in thinking that it cannot be satisfactorily explained by their effect on dead animal matter:

• Increased evacuations cannot be ascribed to mere mechanical laxity of the solids; and their removal cannot be referred to simple condensation of these solids. Neither can it be admitted that active substances may be applied to the system without occasioning changes in the state of the living powers. Many substances arranged as astringents occasion very considerable alterations in several of the functions; they produce effects too which cannot be solely referred to a condensing power, and therefore, in all the changes they produce, part at least of their operation must be referred to their acting on the powers peculiar to life.'

One thing, however, we conceive is sufficiently evident, that they do not act as stimulants; and both their immediate and ultimate effect seems to be that of diminishing action.

We now arrive at the second great division of the articles of the Materia Medica, the local stimulants. These are subdivided into emetics, cathartics, emmenagogues, diuretics, diaphoretics, expectorants, sialogogues, errnines, and epispastics. The author here seems to proceed on the idea that the effect of all medicines must necessarily be stimulant; or in other words that to stimulate is to produce an effect. Emetics are said to cause vomiting, because they stimulate the sto

E 4

mach;

mach; but is it probable that the increase of the action of a part should produce an effect directly the reverse of its natural action? Vomiting, like many other operations of the animal body, may be produced by very different and seemingly opposite causes; mechanical compression of the brain, a blow on a very sensible part of the body, the impression of a disgusting object, bodily fatigue, fainting, local irritation of the throat, all produce the same effect with a dose of ipecacuanha or tartar emetic; yet it cannot be imagined that these causes all operate in the same manner; and still less can we conclude that they all operate by stimulating the stomach, We may apply the same kind of observations to some other of the classes of local stimulants. The medicines that are arranged under the title of diuretics are said to be such as stimulate the kidneys, and thus produce an increase in the flow of urine: but, on referring to the list of substances which are said to possess that power in the most eminent degree, we cannot for a moment imagine that their effects on the system depend on the same kind of action. If we admit that the saline diuretics stimulate the kidneys, can we suppose that squills or digitalis operate in this way? Does vomiting, or do those mental affections which are known to produce a diuretic effect, increase the action of the kidneys?

We have already extended our remarks on the classification of the Materia Medica to such a length, that we must pass over the remainder of the work with more brevity. The account given of the individual articles of the Materia Medica is, we believe, in general correct, though perhaps not always sufficiently minute. Though the arrangement is, in many respects, so objectionable, yet, in stating the medical virtues of the different substances, Mr. Murray has discarded much of his attachment to theory, and has exercised a considerable share of candor and judgment. We have before noticed one instance of this kind with respect to the digitalis, and others of a similar nature might be pointed out. In order to enable our readers to form their own opinion on the merits of this part of the publication, we shall quote the articles of camphor and hemlock; which, we think, may be considered as fair specimens of the execution of the whole;

CAMPHORA. Camphor. Laurus Camphora, Lin. Ch. Enneandria. Ord. Monogynia. Nat. Ord. Oleracea. Habitat Japan, India.

• Camphor is a proximate principle of vegetables, contained in many plants, especially those of the aromatic kind. For the purposes of commerce, it is obtained from a species of laurel, the Laurus Camphora, a native of Japan. It exists in distinct grains in the wood of the roots and branches of this tree. It is extracted by sublimation in Europe, it is purified by a second sublimation, with the addition of one-twentieth of its weight of lime, • Pure

Pure camphor is colourless, semi-transparent, tenacious, and somewhat unctuous to the touch; its smell is strong and fragrant; its taste pungent and bitter. It is volatile at every natural temperature; is fusible in a heat inferior to 212°; is inflammable; scarcely soluble in water, but entirely soluble in alkohol, ether, and oils, essential or expressed. It consists of carbon and hydrogen, and differs from the essential oils, in containing a larger proportion of carbon, with some oxygen. By combustion, it affords carbonic and camphoric acids.

In a moderate dose, camphor produces effects similar to those of other narcotics. Its stimulant operation, however, is not consideraable, even in a small dose; and in a large dose it always diminishes the force of the circulation; induces sleep, and sometimes causes delirium, vertigo and convulsions, ending in total insensibility.

As a stimulant, camphor has been used in typhus, cynanche maligna, confluent small-pox, and other febrile affections accompanied with debility, in retrocedent gout, and to check the progress of gangrene. As a sedative, it is used in affections of an opposite nature, as in pneumonia, rheumatism, and gonorrhoea, combined with nitre or antimonials, or by itself, where evacuations have been made. I mania, it has sometimes succeeded as an anodyne: as an antispasmodic, it has been employed with advantage in asthma, chorea, and epilepsy.

The dose of camphor is from 5 to 20 grains. It cannot be given with safety in a larger dose than half a drachm; and Dr. Cullen has likewise remarked, that in too small a dose, as that of a few grains, it has very little effect. In divided doses it may be given to the extent of a drachm or more in the day. Its power of checking the progress of gangreue is promoted by combination with musk, or carbonate of ammonia: combined with opium, it forms a powerful dia. phoretic; and its efficacy in inflammatory diseases is augmented by antimonials.

Camphor ought generally to be given in a state of mixture in some fluid form, as being then less apt to excite nausea. It may be diffused in water by trituration with sugar, mucilage, or almonds. To reduce it previonsly to powder, a few drops of alkohol must be added. Magnesia, by being triturated with it, has the effect of dis viding and rendering it smooth, and may be used for its suspension; a number of the gum-resins also act on it in such a manner, that, from their mixture, a soft uniform mass is formed, and this affords another mode of diffusing it in water.

Externally applied, camphor is used as an anodyne in rheumatismn and muscular pains, and as a discutient in bruises and inflammatory affections; it is dissolved in alkohol or expressed oil, and applied by friction to the part. Added to collyria, or mixed with lard, it is of service in ophthalmia. Suspended in oil, it is used as an injection in ardor urine, and as an enema to relieve the uneasy sensations occasioned by ascarides. The combination of it with opium is useful as a local application in toothach.

OFFICINAL PREPARATIONS.-Acid: Acetos: Camph. Emuls: Camph. Ol: Camph. Tinct: Camph. Ed.-Mist: Camph. Lin: Camph; Comp. Tinct Opii Camph, Lond.'—

• CONIUM

'CONIUM MACULATUM. Cicuta. Hemlock, Pentand. Digyn. Umbel Lata. Folia, Semen. Indigenous.

'The stalk of hemlock is large and spotted; the leaves are of a dark green colour, have a faint disagreeable smell, and a nauseous herbaceous taste. The seeds are inferior in strength.

Hemlock is a very powerful narcotic. In a very moderate dosc it is apt to occasion sickness and vertigo; in a larger quantity it induces anxiety, dilatation of the pupils, delirium, stupor, and convulsions.

The free internal use of this plant was introduced by Störck. He recommended it particularly in scirrhous and in cancerous sores, in which it received a very extensive trial. While its inefficacy towards effecting a radical cure is established, its utility as a palliative is admitted. Ithas likewise been found serviceable in scrofulous and venereal ulcerations, glandular tumors, chronic rheumatism, and several other diseases. The dose is two or three grains of the powdered leaves, one or two grains of the inspissated juice. It requires to be increased, in general, to a very considerable extent at the same time this must be done with caution, as both the dried leaves and inspissated juice are variable in their strength. The dried leaves are less liable to injury from keeping than the inspissated juice. The drying should be performed quickly before a fire, and the powder should be kept in phials closely stopped and secluded from the light. The proof of the drying having been properly performed, is the powder retaining the odour of the leaves and the deepness and freshness of their colour.

Offic. Prep.-Suce: spiss: Conii Macul. Ed.,

The basis of the third part of Mr. Murray's work, comprized in the second volume, is a translation of the last edition of the Pharmacopæia of the Edinburgh college: but the preparations of the London Pharmacopeia, which are not employed by the Edinburgh college, as well as those in which there is any important alteration in the preparation or composition, are inserted in their proper places. To most of the articles, are added useful and judicious remarks on the nature of the composition, and the particular purposes for which they are employed; and the translation, as far as we have examined it, appears to be accurate. The author has in course adopted the new nomenclature prescribed by the college-this it is not our present business to criticize in detail; and it was certainly incumbent on Mr. Murray to use the terms sanctioned by the highest medical authority of his country. We cannot, however, forbear remarking that the alterations appear to us, for the greatest part, unnecessary; and that many of the new terms are extremely aukward and inconvenient, from their compounded structure, and the number of superfluous words introduced. We regard it as nearly impossible that they should be adopted by the older practitioners, or by those in the lower branches of the profession; and hence that confusion, so much to be deprecated in pharmaceutical language, must inevitably ensue, After all the

sacrifices