any general action on the animal economy. The proposition, indeed, constitutes the basis of his treatise on the art of prescribing; and in enunciating it, he says:

"I am not the first who has thought that the liquid form is more proper for absorption than the solid; nor am I the first physician who has thought that certain insoluble medicinal agents, such as iron and magnesia, do not become active until after they have been submitted to the dissolving action of the gastric juice; but I think that I am the first who has formally proclaimed that no metal, no oxide, no saline compound, &c., can become active until it is rendered soluble, and I think that I am also the first who has traced the laws which preside over this chemical action." (p. xx.)

In all of Mialhe's formulæ, efforts are therefore made to bring the medicine into the condition of a soluble compound, and he frequently associates it with matters which have a tendency to counteract any irritating properties which it may possess: thus, in prescribing mercury, he generally makes choice of the bichloride of this metal, and he associates it with sal-ammoniac, common salt, and certain organic matters which deprive it of its corrosive and irritating action. By adopting a principle of this kind, and by administering medicines in a soluble form, we prevent, says Mialhe, the chance of their accumulating in the alimentary canal, and we can also predict, with the greatest accuracy, the effect which any dose will produce. On considering the importance of these objects, together with the irrational manner in which medicines are commonly prescribed, it is somewhat surprising that our leading writers on pharmacology have not endeavoured to frame a series of rules for the proper association and administration of remedies. It does, in fact, appear to us to be a striking inconsistency, when we find authors labouring to become acquainted with the origin of abstruse therapeutical terms, and striving to coin others which are no less obscure; then busying themselves about the synonymes, history, natural history, commercial value, and all else which is comprehended by that great word pharmacognosy, or the commerce of drugs; while they are manifestly ignorant and unconcerned about the best methods of employing their remedies. Let any one take a survey of what Dr. Golding Bird has denominated our therapeutic weapons; let him attempt to enumerate them, and to ascertain the value of their respective claims to the physician's notice: and he will not fail to perceive that their number is too great to be manageable, and that many of our preparations are useless and uncertain; for, to take an instance, where is the necessity for so many preparations of iron, of mercury, of antimony, &c.?

Truly did Sydenham remark, when he was commenting on the first of these compounds, "that busy chemists will make this, as well as other excellent medicines, worse rather than better, by their perverse and over-officious diligence." In fact, a great many of our therapeutic agents might be expunged from the materia medica, without loss to practical medicine; for it must be admitted, that the act of curing disease is not founded upon the knowledge of many drugs, but upon the right use of a few.

We find, on referring to the work of Dr. Pereira, that very little is said with respect to the form in which medicines should be administered; indeed, that author has disposed of the subject in less than one page, and

much of what he has said is derived from the writings of Dr. Paris. So, also, with the French writers Trousseau and Pidoux; they do not appear to attach a very great deal of importance to this matter, and we are, therefore, compelled to turn for information to the treatise of Mialhe.

According to the last named author, metals should never be administered in their uncombined state, for their action is dependent on the influence of a limited and unknown quantity of some special solvent. And for the same reason, all insoluble remedies, as calomel, bismuth, oxide of zinc and of iron, &c, should be given in small and repeated doses, so as to ensure their complete solution and absorption.

In speaking of the mercurials, Mialhe states that, in order to excite the general action of this metal, we should always employ the bichloride of it, for we can thus be quite certain of the amount which is admitted into the circulation. In this opinion he is supported by Dr. Pereira, who says: "The balance of evidence is decidedly favorable to the employment of this medicine as an internal remedy for venereal diseases" (p. 862); but he afterwards remarks," that few have ventured to employ the perchloride of mercury in acute diseases; however, Schwartz gave it in hepatitis, after the fever and pain had subsided; Sauter employed it in an epidemic scarlet fever; and Berends administered it in asthenic malignant fevers" (p. 862) while "Mr Lempriere, who practised in Jamaica, finding that calomel was often exhibited in immense quantities, without exciting any apparent action, was induced to employ corrosive sublimate, in doses of the part of a grain, with the addition of ten drops of laudanum, and this quantity was repeated every hour until some affection of the mouth was observed, or until the more alarming symptoms had considerably abated" (p. 826).

Mialhe says, that the bichloride should always be administered in very small doses, as from the to the of a grain daily; and that it should be given in solution, with a little common salt and muriate of ammonia, as the latter substances keep the bichloride soluble, and prevent it from acting on the tissues of the alimentary canal. He states, moreover, that this action may be still further reduced by mixing the medicine with almond emulsion or white of egg. According to Mialhe, corrosive sublimate should never be given in substance, and we ought to avoid the admixture of it with those saccharine and extractive matters which have the power of decomposing it The normal mercurial liquor of this author is composed of distilled water, 16 oz.; salt and muriate of ammonia, of each 15 grains; corrosive sublimate, 5 grains; and the white of one egg. The white of egg and water are first to be mixed and filtered, then the alkaline chlorides added, and lastly, the bichloride. Each fluid ounce of the solution contains rather less than of a grain of the bichloride. It is, therefore, a little weaker than our pharmacopoeial preparation, which contains about a grain of corrosive sublimate in each ounce.

The bichloride of mercury cannot, according to Mialhe, be substituted for calomel when we wish to produce a purgative action; for, in the first place, it is rapidly absorbed, and will hardly ever reach the intestines; and, secondly, if we were to give it in sufficient quantity to produce purgation, it would become a mortal poison.

The author has introduced an ointment of corrosive sublimate, consisting of bichloride of mercury, 1 part; muriate of ammonia, 2 parts; and 7-17.

13*

lard, 7 parts. This ointment is to be employed in quantities varying from 15 grains to a drachm. He says that it is a most active preparation, the activity of it being considerably increased by the alkaline chloride; and that it may be employed instead of blue ointment in the abortive treatment of certain local inflammatory affections.

The preparations of iron. Authors still disagree with regard to the comparative value of these preparations. For instance, Trousseau and Pidoux think with Sydenham, that iron is most active when it is given in a metallic form. Desormeaux and Blache state that the black oxide and the proto-carbonate are the best preparations of it. Bouchardat, believing that the protoxide of the metal is the active agent, says that it ought to be given as a proto-carbonate or as a proto-organic salt. Lastly, Merat and Delens, together with the greater number of English physicians, are of opinion that iron may be advantageously employed in any form; but that this is a great error is evidenced by the fact, that many of the preparations of iron are given in very variable doses, without any constancy of result. Thus, iron filings are administered in quantities which vary from 10 to 30 grains; the black oxide in proportions which extend from 5 to 20 grains; and the red oxide in amounts which range from 10 to 240 grains, the greater part of the mineral being, in each case, carried through the body without exciting any therapeutical action whatever. These facts have induced Mialhe to undertake a new examination of the subject; and, as we have before said, he concludes that the potent agent in all the martial preparations is the peroxide, and that only those compounds of iron can be advantageously employed in medicine, which are soluble in the gastric juice, and which are capable of being decomposed, either directly or indirectly, by the free or carbonated alkalies. To this class belong metallic iron, the oxide, bromide, chloride, iodide, and all the oxy-salts. He states, moreover, that these preparations are not equally valuable, but that the soluble salts of iron are by far the most active, and of these he gives the preference to the potassio-tartrate; for he says that it is a very soluble salt; that it has little or no taste; that it agrees well with the stomach; that it includes the peroxide of the metal; that it is not decomposed either by the acids of the stomach or by the alkalies of the intestines; that it is capable, therefore, of being absorbed through the whole course of the alimentary canal; and that, on getting into the blood, its organic acid is consumed, and the peroxide is precipitated in a state of combination with albumen, which is best suited for the reproduction of blood-corpuscles.

The preparations of lead, silver, gold, and platinum ought, according to Mialhe, to be given with an alkaline chloride.

Sulphur. This substance being dependent on the alkalinity of the secretions for its solution, it ought to be administered with some alkaline or earthy base. The same remark applies to the resins, and to oleaginous substances. While, on the other hand, the vegetable alkalies, from their being but slightly soluble in water or the intestinal secretions, ought to be given with acids as super-salts; and this rule, says Mialhe, should be especially attended to when the alkaloids are administered in large doses, for unless they are absorbed from the stomach, they are not likely to gain access to the circulation.

A very slight consideration of the chemical principles which are here

set forth, will show that medicines ought not to be mixed together indiscriminately, but that they should be associated in accordance with certain rules. It should be remembered, says Mialhe, that when we administer several remedies at the same time, one of three things will happen; either ecch of the medicines will act in its own proper manner, as if it had been administered alone, or one of the substances will augment the action of the other, or the associated bodies will diminish or even annihilate each other's action.

As instances of the first, we may mention all those soluble substances which do not interchange elements with each other; as, for example, the alkaline and earthy sulphates; the sulphates of quinia cinchonia; the various vegetable astringents, &c.

As instances of the second, Mialhe states, that we may increase the purgative action of scammony by combining it with almond oil, and that we may augment the cathartic effects of oils and resins by administering them with a little calcined magnesia. Moreover, the association of such substances as do not require the same solvent will always tend to augment their general effect: thus, to take one example, clinical experience has shown that a mixture of calomel and jalap acts in a much more marked manner than does a considerable dose of either of these bodies given separately. This arises from the fact that the calomel appropriates the soluble chlorides of the alimentary canal, while the jalap effects a union with the alkalies thereof. Again, it has been remarked, that iodide of potassium increases the action of mercurials; and, according to Mialhe, the same thing occurs when prussic acid is administered with a salt of mercury.

Lastly, as instantes of one medicine weakening, or even altogether preventing, the effects of another, we may refer to the mixture of those substances which require the same solvent for their action, as chalk and magnesia, magnesia and subnitrate of bismuth, magnesia and quinia, magnesia and iron, oxide of zinc, &c.; all of which substances require the agency of the gastric juice in order to be rendered soluble. As other examples, we may mention the association of medicines, which mutually decompose each other, and thereby produce insoluble and inert compounds.

It would here be proper to refer to the rationale of the action of antidotes; but as we have already discussed this matter in a former volume (Vol. II, p. 241), we may be excused from again entering upon it. It may not, however, be superfluous to state, that the criticisms which we there passed on Mr. Taylor's definition of an antidote, are fully supported by the opinions entertained by Dr. Pereira; for, in speaking of, the counter-poisons, at p. 150, he uses almost the same words, and adopts the same classification as we did upon the occasion to which we refer. We may likewise mention that Mialhe seems nearly to have reached that " consummation so devoutly to be wished," the discovery of an universal antidote; for he says, that the hydrated protosulphuret of iron is endowed with the power of neutralizing the effects of nearly all the metallic poisons, as the salts of tin, lead, copper, zinc, bismuth, mercury, silver, gold, platinum, antimony, and arsenic indeed he regards it as the antidote " par excellence" to the last-named mineral; and his conclusions are, in the main, verified by the more recent inquiries of Bourchardat and Sandras.

Another set of counter-poisons to which we might refer, are the prophylactics; but our space will not permit us to discuss them here.

And now, in concluding our review of Mialhe's work, we are bound to state that this investigator has done much to improve our knowledge respecting the action of remedies, and to expose that blind empiricism which has hitherto been mixed up with the science of therapeutics. Thus far, therefore, his efforts deserve our warmest praise; but, in our admiration of these efforts, we must not be blind to the fact, that Mialhe has often gone beyond the boundary of safe speculation, and that he has frequently constructed hypotheses upon assumptions, rather than upon well-established data. We may truly say, therefore, that while a contemplation of the general results of his labors may be made with much profit, it would not be advantageous to scrutinize them individually.

We approach our last question, namely, that which refers to the application of chemistry to the discovery and cure of disease, with much. diffidence For, in the first place, even though our inquiries into the chemical composition of the animal fluids and solids have been limited almost entirely to the blood and urine, two fluids which have received the greatest share of attention from pathological chemists, yet, on passing in review the countless examinations which have been made of these fluids, we find that our knowledge respecting the changes to which they are liable during the existence of diseased action is far from being complete or satisfactory; secondly, we are, comparatively speaking, ignorant of the influence which remedies exert over the composition of the healthy and diseased structures; and lastly, we know but little of the changes to which the remedies themselves are subject during their passage through the animal body. How, therefore, until our information is more complete on these subjects, can we expect to be able to make a successful appli cation of chemistry, either to pathology, or to practical medicine? Nevertheless, we are sanguine enough to believe, that the time is not far distant when the greatest benefit will be derived from such an association of these sciences. In fact, even with our present imperfect knowledge, the chemist has been enabled to give an interpretation of many of the phenomena of disease, and he has been bold enough to construct hypotheses, which, with a little modification, may, perhaps, bear the test of future investigations. Among these hypotheses, there is one to which we have frequently referred in the pages of this journal-on hypothesis which accounts for the phenomena of fever, plague, cholera, small pox, scarlatina, and, indeed, of the whole of the exanthemata, on the supposition that they are dependent on a species of fermentation, which is due to the introduction of a decomposing organic molecule into the interior of the living body; and with reg ird to which, it is remarked by Liebig, to whom we owe its revival in its present form, "practical medicine will soon decide whether this view is just, or whether it is to be rejected."

It may, however, be asked, is there, in the first place, any evidence to show that the introduction of putrid matter into the animal system does give rise to effects which are at all comparable with those of fever, &c., or even that a state of transformation or putrefaction is propagated to the constituents of the living body. Now, as Liebig remarks,

"It is a fact, that subjects in anatomical theatres frequently pass into a state of