It is a

To deny cutaneous absorption altogether is impossible. channel, in fact, by which we introduce one of our most active remedial agents into the system;-and it has not unfrequently happened, where due caution has been omitted, that the noxious effects of different mineral and other poisons have been developed by their application to the surface, but it is by no means common or easy, when the cuticle is sound, unless the substance employed possesses unusually penetrating properties. M. Chaussier found, that to kill an animal, it is sufficient to make sulphuretted hydrogen gas act on the surface of the body, taking care that none gets into the air-passages; the researches of Prof. J. K. Mitchell' have also shown that this gas is powerfully penetrant. Unless, however, the substances, in contact with the epidermis, are of such a nature as to attack its chemical composition, there is usually no extensive absorption.

It is only of comparatively late years, that physiologists have ventured to deny, that the water of a bath, or the moisture from a damp atmosphere, is taken up under ordinary circumstances; and if, in such cases, the body appears to have increased in weight, it is affirmed, and with some appearance of truth, that this may be owing to diminution of the cutaneous transpiration. It is, indeed, probable, that one great use of the epidermis is to prevent the inconveniences to which we should necessarily be liable, were such absorption easy. This is confirmed by the fact, that if the skin be deprived of the epidermis, and the vessels that creep on the outer surface of the true skin be thus exposed, absorption occurs as rapidly as elsewhere. J. Müller affirms, that saline solutions applied to the corium penetrate the capillaries in a second of time. To insure this result in inoculation and vaccination, the matter is always placed beneath the cuticle; and, indeed, the small vessels are generally slightly wounded, so that the virus gets immediately into the venous blood. Yet-it is proper to remark-the lizard, whose skin is scaly, after having lost weight by exposure to air, recovers its weight and plumpness when placed in contact with water; and if the scaly skin of the lizard permits such absorption, M. Edwards thinks it impossible not to attribute this property to the cuticle of man. When the epidermis is removed, and the system is affected by substances placed in contact with the true skin, we have the endermic method of medication.

M. Séguin' instituted a series of experiments to demonstrate the absorbent or non-absorbent action of the skin. His conclusion was, that water is not absorbed, and that the epidermis is a natural obstacle to the action. To discover, whether this was the case as regarded other fluids, he experimented on individuals labouring under venereal affections, who immersed their feet and legs in a bath, composed of sixteen pints of water and three drachms of corrosive chloride of mercury, for an hour or two, twice a day. Thirteen, subjected to the treatment for twenty-eight days, gave no signs of absorption; the fourteenth was manifestly affected, but he had itchy excoriations on the legs; and the

1 Amer. Journal of the Med. Sciences, vii. 44; and p. 68 of this work.

2 Annales de Chimie, xc. 185.

VOL. I.-44

.

same was the case with two others. As a general rule, absorption exhibited itself in those only whose epidermis was not in a state of integrity. At the temperature of 74° Fahrenheit, however, the sublimate was occasionally absorbed, but never the water. From other experiments, it appeared evident, that the most irritating substances, and those most disposed to combine with the epidermis, were partly absorbed, whilst others were apparently not. Having weighed a drachm (seventy-two grains, poids de marc) of calomel, and the same quantity of camboge, scammony, salt of alembroth, and tartar emetic, M. Séguin placed an individual on his back, washed the skin of the abdomen carefully, and applied to it these substances at some distance from each other, covering each with a watch-glass, and maintaining the whole in situ by a linen roller. The heat of the room was kept at 65°. M. Séguin remained with the patient, in order that the substances should not be displaced: and he protracted the experiment for ten hours and a quarter. The glasses were then removed, and the substances carefully collected and weighed. The calomel was reduced to 713 grains. The scammony weighed 713; the camboge, 71; the salt of alembroth, 62 grains,' and the tartar emetic 67 grains.2

It requires, then, in order that matters shall be absorbed by the skin, that they shall be kept in contact with it, so as to penetrate its pores, or the channels by which the cutaneous transpiration exudes; or else that they shall be forced through the cuticle by friction,-the iatraleptic mode. In this way, the substance comes in contact with the cutaneous vessels, and enters them probably by imbibition. Certain it is, that mercury has been detected in the venous blood by Colson, Christison, Cantu, Autenrieth, Zeller, Schubarth, and others.3

4

Not long after the period that M. Séguin was engaged in his experiments, Dr. Rousseau, of Philadelphia, contested the existence of absorption through the epidermis, and attempted to show, in opposition to the experiments we have detailed, that the pulmonary organs, and not the skin, are the passages by which certain substances enter the system. By cutting off all communication with the lungs, which he effected by breathing through a tube communicating with the atmosphere on the outside of the chamber, he found, that although the surface of the body was bathed with the juice of garlic, or the spirit of turpentine, none of the qualities of these fluids could be detected, either in the urine, or the serum of the blood. From subsequent experiments, performed by Dr. Rousseau, assisted by Dr. Samuel B. Smith, and many of which Professor Chapman witnessed, the following results were deduced. First, That of all the substances employed, madder and rhubarb were those only that affected the urine,-the latter of the two more readily entering the system; and secondly, that the power of absorption is limited to a very small portion of the surface of the body.

1 Several pimples were excited on the part to which it was applied.

2 Magendie's Précis, &c., ii. 262.

3 The author's General Therapeutics and Materia Medica, 4th edit., i. 90, Philad., 1850. 4 Experimental Dissert. on Absorption, Philad., 1800.

5 Philad. Medical Museum, i. 34, Philad., 1811.

• Elements of Therapeutics and Materia Medica, 6th edit., i. 65, Philad., 1831.

The only parts, indeed, that seemed to possess it, were the spaces between the middle of the thigh and hip, and between the middle of the arm and shoulder. Topical bathing, with a decoction of rhubarb or madder, and poultices of these substances applied to the back, abdomen, sides, or shoulders, produced no change in the urine; nor did immersion of the feet and hands for several hours in a bath of the same materials afford the slightest proof of absorption.

From these and other facts, sufficiently discrepant it is true, we are justified in concluding, that cuticular absorption, under ordinary circumstances, is not easy; but we can readily conceive, from the facility with which water soaks through animal tissues, that if the animal body be immersed sufficiently long in it, and especially if the vessels have been previously drained, imbibition may take place to a considerable extent. This, however, would be a physical absorption, and might be effected as well in the dead as in the living body.

b. Other Accidental Absorptions.

Amongst the adventitious absorptions have been classed all those that are exerted upon substances retained in the excretory ducts, or situate in parts not natural to them. The bile, arrested in one of the biliary ducts, affords us, in jaundice, a familiar example of such absorption by the positive existence of bile in the blood vessels; although the yellow colour has been gratuitously supposed to be caused by an altered condition of the red globules, and not by the presence of bile. This condition of the red globules would account for some of the symptoms,as the yellow colour of the skin, and urine,-but it does not explain the clayey appearance, which the evacuations present, and which has been properly ascribed to the absence of the biliary secretion. We have, moreover, examples of this kind of absorption, where blood is effused into the areolar membrane, as in the case of a common sprain, or in those accumulations of fluid in various cavities, that are found to disappear by time;-the serous portion being taken up at first with some of the colouring matter, and, ultimately, the fibrin. In the case of accumulation of the serous fluid, that naturally lubricates cavities, it is of such a character-the aqueous portion at least-as to be imbibed with facility, and probably passes into the veins, in this manner, the functions of exhalation and absorption consisting mainly, in such case, of transudation and imbibition.

But absorption is not confined to these fluids. It must, of course, be exerted on all morbid deposits; and it is to excite the action of the absorbents, that our remedial agents are directed. This absorption-in the case of solids-is of the interstitial kind; and, as the morbid formation has to undergo an action of elaboration, it ought to be referred to lymphatic agency.

To conclude the function of absorption:-All the products,-whether the absorption has been chyliferous, lymphatic, or venous,-are united in the venous system, and form part of venous blood. This fluid must, consequently, be variable in its composition, in proportion to the quantity of heterogeneous materials taken up by the veins, and the activity

of chyliferous and lymphatic absorption. It is also clear, that, between the parts of the venous system into which the supra-hepatic veins,loaded with the products of intestinal absorption of fluids,-enter, and the opening of the thoracic duct into the subclavian, the blood must differ materially from that which flows in other parts of the system. All, however, undergo admixture in their passage through the heart; and all are converted into arterial blood by the function, that will next engage us,-RESPIRATION.

END OF VOL. I.

OF

BLANCHARD & LEA'S

MEDICAL AND SURGICAL PUBLICATIONS.

TO THE MEDICAL PROFESSION.

In submitting the following catalogue of our publications in medicine and the collateral sciences, we beg to remark that no exertions are spared to render the issues of our press worthy a continuance of the confidence which they have thus far enjoyed, both as regards the high character of the works themselves, and in respect to every point of typographical accuracy, and mechanical and artistical execution. Gentlemen desirous of adding to their libraries from our list, can in almost all cases procure the works they wish from the nearest bookseller, who can readily order any which may not be on hand; and who, as well as ourselves, will be happy to answer any inquiries as to price, &c.

PHILADELPHIA, September, 1855.

BLANCHARD & LEA.

TWO MEDICAL PERIODICALS, FREE OF POSTAGE, FOR FIVE DOLLARS PER ANNUM.

THE AMERICAN JOURNAL OF THE MEDICAL SCIENCES, subject to postage, when not paid for in advance,

THE MEDICAL NEWS AND LIBRARY, invariably in advance,

or, BOTH PERIODICALS furnished, FREE OF POSTAGE, for Five Dollars remitted in advance.

$5.00

1 00

THE AMERICAN JOURNAL OF THE MEDICAL SCIENCES,

EDITED BY ISAAC HAYS, M. D.,

is published Quarterly, on the first of January, April, July, and October. Each number contains at least two hundred and eighty large octavo pages, handsomely and appropriately illustrated, wherever necessary. It has now been issued regularly for more than THIRTY-FIVE years, and it has been under the control of the present editor for more than a quarter of a century. Throughout this long period, it has maintained its position in the highest rank of medical periodicals both at home and abroad, and has received the cordial support of the entire profession in this country. Its list of Collaborators will be found to contain a large number of the most distinguished names of the profession in every section of the United States, rendering the department devoted to

ORIGINAL COMMUNICATIONS

full of varied and important matter, of great interest to all practitioners.

As the aim of the Journal, however, is to combine the advantages presented by all the different varieties of periodicals, in its

REVIEW DEPARTMENT

will be found extended and impartial reviews of all important new works, presenting subjects of novelty and interest, together with very numerous

BIBLIOGRAPHICAL NOTICES,

including nearly all the medical publications of the day, both in this country and Great Britain, with a choice selection of the more important continental works. This is followed by the