gum, gluten, pectin, vegetable albumen, glucose, sugar, fixed oils, and other analogous principles, all those elements which are digestible and capable of sustaining animal life, are insoluble in pure alcohol, while the resins, alkaloid salts, essential oils, and those fixed oils which are medicinal, are soluble in that menstruum.

It is at once objected to these views, that there are many vegetable substances from which pure alcohol will not extract the medicinal virtues; that for this purpose water, dilute alcohol, acids, ether, or other agents are requisite, and are hence prescribed in our pharmaceutical formulæ. It is true that to eliminate these principles in the first place from their native combinations in the plant, such agents are necessary, not because such medicinal principles are not themselves soluble in alcohol, but because they are so enveloped in and shielded by other principles which are not soluble in that menstruum that it cannot reach them.

If we dissolve a mixture of gum acacia and muriate of morphia, and reduce the solution to dryness and a coarse powder, strong alcohol will not dissolve out the morphia from that powder, not because it is not soluble in the alcohol, but because it is protected by the insoluble gum. But, if now we redissolve this mass and pour the solution into a proper quantity of strong alcohol, the gum will be precipitated and the morphia remain in solution, and may thus be recovered and isolated.

So, in extracting the virtues of most plants it is necessary, or at least expedient, to use other agents besides alcohol to bring into solution all their elements, and thus disengage the principles we seck. In most cases water is necessary as one of these agents for the purpose of dissolving the nutritive principles and expanding the vegetable fibre. In some cases the medicinal elements are found enveloped in others which are not soluble either in water or alcohol, as wax, caoutchouc, and the fatty oils. Then we require ether, benzole, or camphene, for their perfect and speedy elimination, but when once freed from such shielding substances the medicinal elements are all found to be soluble in alcohol alone. When the principle sought is a fixed medicinal oil, we find ether to be used to great advantage, because it dissolves that principle to the exclusion of most others, and thus presents the medicine in a very pure and concentrated form, as in the ethereal extract of ergot, capsicum, filix mas, etc., but, when so obtained, the ether may be replaced by alcohol, and all that is medicinal held in solution by that grand solvent.

But while alcohol is the specific solvent of all the medicinal elements of vegetation, they are most of them while in their native combinations soluble in water also; this is the most universal solvent in nature. This alone will probably extract all the virtues of jalap and podophyllum, and leave little but the inert vegetable fibre. For the resinous principles of these roots, in their natural state, are held in such intimate combination with the other elements, that they are dissolved out and held in solution with them. Thus the watery extracts of such roots actually contain their medicinal virtues, although greatly diluted with other non-medicinal principles. But, if that native combination is once broken up or disturbed, those resinous principles separate and are not again soluble in that menstruum. When obtained, however, by this or other injudicious

processes, these resinoid principles, and perhaps others originally medicinal, are liable to become so changed in their original constitution by the action of heat, water, and oxygen, as to be no longer soluble in alcohol, and just so far as this is the case their medicinal properties are destroyed and they become inert. Thus the medicinal value of jalapin, podophyllin, leptandrin, and the other resinoids, may be correctly estimated by their solubility in alcohol, for so far as they are thus insoluble they are worthless.

Many vegetables which we habitually use as wholesome esculents, contain some elements soluble in alcohol, but these when separated and concentrated will be found to be active medicines or poison. In themselves they are not nutritious but medicinal, but in the small proportions in which they are found in our food, they may, like the pepper, and ginger, and cayenne, and common salt, which we use as condiments, serve as healthful stimulants to the digestive organs, and thus aid in the assimilation of those substances which are really nutritive.

I have above advocated the truth of this hypothesis as applied to vegetable substances only; but if the bone phosphate of lime (which, I believe, is not soluble in alcohol) is entirely inert, as is the opinion of Prof. Wood, then I know of no exception to its application to the whole animal kingdom also.

I wish it to be understood, however, that I contend for the application of this law only to those proximate principles of organic matter which are properly the products of vegetable and animal life. Among the multifarious combinations of the primary elements which are the results of the destructive decomposition of vegetable and animal matter, there may be found exceptions to this rule; some preparations may be found which are medicinal or poisonous, and yet not soluble in alcohol, but that is foreign to our present inquiry.

To prove this hypothesis affirmatively would require the enumeration of every article of the vegetable Materia Medica, with testimony to the solubility of its medicinal principle in alcohol; we can therefore only offer the negative proof of challenging the production of facts that militate against it. These we believe, if any, will be found so few that the exceptions will but establish the rule.

The importance and application of this law will be readily appreciated. The particular modes of manipulation must be left to the judgment of the pharmaceutist, and must be greatly varied according to the nature of the substance operated on.

The general rule of operation will be this: In the first place, extract from the crude material all its soluble elements, or at least be sure that we have reached and eliminated all those medicinal principles which we seck. For this purpose we may employ water, alcohol, ether, or other agents, or these combined or in succession, as experience and pharmaceutical knowledge may indicate. Then, from this primary tincture or solution, draw off, by the still or the vacuum pan, the menstruum used, and reduce the extract to a semi-fluid or syrupy consistence, leaving as little fluid as practicable to dilute the alcohol to be used, and yet retain sufficient fluidity to allow all the particles to come fully in contact with

this solvent. Next weaken this semi-fluid extract with absolute alcohol or, at least, with that of such strength as will not dissolve the nutritive and inert principles. In doing this, use, in the first place, about twothirds or three-fourths the quantity for the proposed volume of the finished tincture, and after sufficient agitation and digestion in this, decant or filter off the clear liquid and set it aside. Treat the remaining precipitate with repeated portions of alcohol till nothing more is dissolved, and distil off the spirit from these weaker solutions till the quantity left, when added to the former strong solution, will make up the measure proposed. If this, from inferiority of the materials used, is not of the specific gravity adopted, it may be further concentrated.

If the material to be extracted contains any essential oil or other volatile principle, this must first be drawn off and set aside, to be added at the close of the process, or to be used as part of the menstruum in the second part of the process. This is best done, not by distilling over, but by displacing downwards by the vapor or alcohol in the vapor displacement apparatus, an improvement which we now employ. But as my object now is to develop a general law and its uses, and not to give particular formulæ, I will not dwell longer on these manipulations.

In this way alcoholic solutions may be obtained of almost any desired degree of concentration; for as the solvent power of the menstruum is no longer diminished by the presence of water or foreign matters, it becomes, in regard to many substances, limited only by the consistence of the solution. In general, however, the concentration now generally adopted for the fluid extracts, in which each fluid-drachm represents the strength of 60 grains of the material, is a convenient one, and is easily attainable with almost every plant, but other standards may be adopted as found expedient.

We believe that pharmaceutical preparations made in accordance with the above hypothesis will be found superior in most cases to those now in use.

In all the formulæ now in use, or which I have seen recommended for fluid extracts, much of the volatile principles of the plant are dissipated in the concentration and lost; by this plan all are preserved. In those formulæ, the removal of the alcohol necessarily results in the precipitation of the resinous principles which, when such principles predominate, as in the jalap and leptandra, the amount of sugar recommended will not keep suspended, nor the addition of one-fifth or one-fourth of alcohol, as practiced by later manufacturers, hold in solution. These must, therefore, be removed at the expense of the medicinal power of the preparation, or else give to it a turbid and disgusting appearance. In our proposed tinctures, on the contrary, all such principles are held in perfect and permanent solution, and they are not, like the old fluid extracts, liable to change from fermentation or loss by freezing.

Such essential tinctures may be made much more perfect and definite representatives of the material from which they are prepared, than the common officinal tinctures, and may be dispensed with the greatest precision, while they are vastly superior to those old preparations, in occupy ing but one-eighth to one-fourth the space, and especially in their con

taining so small an amount of stimulant in proportion to their medicinal power, that this ceases to be an objection to their administration. Should cases occur, which may in one out of fifty, in which the physician apprehends that the few minims contained in the prescribed dose would unfavorably affect the patient, he has only to drop the tincture on a little sugar in a tea-cup, and pour on to it a spoonful of hot water, and by the time it is well mixed and cool all the alcohol will be dissipated, and the medicine left diffused in the sweetened water.

And here I will observe in passing, that no medicines, and especially those of an active character, should be thrown naked into the stomach in their concentrated forms. Such forms are exceedingly convenient for carrying and for definite dispensing, and, I may add, for exhibiting to the patient as small and delicate doses; but in administering them, they should almost always be diffused in syrup, gruel, or other bland liquid. Or, if in pills, they should be so combined as to render the solution in the stomach gradual and diffusive.

I may further remark, that if tinctures of the officinal strength are required, they may be instantly prepared from these concentrated solutions by the simplest formulæ and in the greatest proportion. Or by adding them in proper quantity to warm simple syrup, beautiful medicinal syrups of any desired strength may be cheaply produced.

But it is not to the preparation of fluid extracts or concentrated tinctures only that the law and the processes I propose are applicable. If we pour such tinctures into water, the resinoid principles will be precipitated; thus, jalapin, podophyllin, macrotin, etc., may be obtained in their purest form. If such tinctures be evaporated to the pillular consistence, they form true alcoholic extracts, which are more active, more definite, more uniform, and more permanent, than any that can be otherwise prepared. Or again, if they do not contain fixed oils or oleo-resins, the evaporation may be carried to dryness, and the powdered extracts form convenient, definite, and powerful agents; such, indeed, as are some of the so-called "concentrated medicines" now offered to the medical profession and approved as valuable preparations.

Indeed, preparations formed in accordance with these views, will, in many cases, be found superior to the fine crystallized chemicals which have been considered the climax of pharmaceutic skill, inasmuch as in these latter the normal constitution of medicine is always broken up, and new and artificial combinations formed, which do not act on the system precisely as the original organic salts as they exist in the plant; while in these alcoholic extracts, whether fluid, pillular, or powdered, the medicinal principles exist in combination with their own native acids or bases, and thus truly represent the plant in substance; and, if our theory be true, will contain only those elements which are more or less medicinal, to the exclusion of the inert matter.

But I have extended my paper already, I fear, beyond its acceptable limits, and will therefore leave the above suggestions to the consideration and criticism of whom they may concern.-American Journal of Pharmacy, January, 1859.

From the London Medical Circular.

A CLINICAL LECTURE ON INFILTRATING FORMS OF SUPPURATION AND TREATMENT OF ABSCESSES.

By F. C. SKEY, Esq., F.R.C.S., F.R.S., etc., etc.

SURGEON TO ST. BARTHOLOMEW'S HOSPITAL.

[Taken in conjunction with previous lectures by Mr. Skey, reported specially for the Medical Circular, and reflecting as it does the best practice of the London hospitals for all our leading men are now coming over to the views of Dr. Todd, Dr. Hughes Bennett, and the able clinical professor of St. Bartholomew's, we feel especial pleasure in publishing the following lecture, one of a series delivered this month.]

GENTLEMEN:-I do not know that we can begin the new year better than by offering you to-day some plain remarks on a very plain subject, yet a subject of universal interest to us in clinical practice. I mean the subject of abscess, and the peculiarities of various suppurations, as we see them in the wards and out-patients' department of this hospital. You would prefer probably some other great and grand subject; that we should, for instance, dive into the arcana of silver sutures, diphtheria, or tracheotomy; or take up the treatment of surgical aneurism, pressure or no pressure in that disease; ovariotomy, or any thing you like, and

"That to the height of this great argument"

we should ascend and fret ourselves in useless dogmatism; but no, these things only appertain to men who see matters on a scale we are not accustomed to. I am, as you know, a man for "rudiments." Certainly, standing here as your clinical teacher, I prefer to dwell on that which is useful to you-nay, I would add, that on which, on the whole, you will feel greatest pleasure hereafter, I mean inflammation and its proper treatment, and the allied subject-suppuration and abscesses.

Well, what is an abscess? "A collection of matter surrounded by a cyst," you will answer, (and it is as good a definition as any ;) and then if further pressed you say, "this cyst is composed of a membrane, pyogenic in its nature"-that's an abscess. The matter must be collected, for you may have infiltrated abscess in the mammary gland (and brain?) which will not obey your definition; about that I am not now so much interested, but from the cases recently in the hospital, we are more engaged with the division into "acute" abscesses and "chronic" abscesses. Suppuration, you very well know, may take place in any texture or surface of the body that is furnished with blood-vessels, and is susceptible of the process of inflammation; but I doubt very much the value of this old division, "acute" and "chronic" abscesses. I see in the wards, as I take it, an abscess that partakes of one character and