seven-day fever the diminution of the fatty swellings was too evident and remarkable to admit of doubt, while the improvement of his general health was equally striking and satisfactory.

Hydriodate of Potassium is one of the best proved remedies in all hypertropic diseases.

MALFORMATIONS.-The greatest evil of psora is that it reproduces itself and descends to posterity. The children of psoric parents are born with some of its manifestations. Thus:-Malformations, as tumors on the head, yellowish, sallow color of the skin; head too large; phthisical conformation; itch eruptions; they are liable to scald-head, &c. Towards the end of the 15th century psora culminated in syphilis, since the appearance of which lepra has nearly disappeared, though it still remains in a few countries. (See Lepra.)

GENUS V.-PHYSICAL DEFORMITIES.

CRETINISM.

We have already spoken of this terrible infirmity of human nature in its relations to imperfect development of the mind; it is proper to refer to it here as a physical deformity. The cretin is a blighted specimen of humanity. His stature is not more than four or five feet, often less; the head is deformed in shape and is too large for the body; skin yellow, cadaverous, or of a mahogany color, wrinkled, pallid, or marked by eruptions; the flesh is soft and flabby; the tongue large and often hanging out of the mouth; the eye-lids thick; the eyes red, prominent, squinting; the countenance is void of all expression except that of idiotism; the nose is flat, the mouth large, gaping, and constantly permitting the saliva to flow over the elongated lower jaw. The abdomen is pendulous, the limbs crooked, short, and so distorted as to prevent any but a "waddling" progression. The external senses are often imperfect,—many are deaf and dumb,—and the whole aspect presented is that of premature old age. Such is the disgusting physical exterior of the apparently wretched, but, perhaps, completely happy

cretin.

His moral picture is still more humiliating. The intellectual faculties are suspended, while the lower animal propensities are in a state of increased activity; the cretins are voracious eaters, and addicted to the lowest animal passions. Their chief pleasures are to eat and sleep; or, after eating, to bask in the sun, insensible to every stimulus that agitates the mind of savage or civilized man. "Goitre, on such a scale as we see it in the valleys of the Alps is bad enough, but cretinism is a cure for the pride of man, and may here be studied on a large scale and in its most frightful colors." (Johnson, on Change of Air.)

TUMOR. A Tumor on the Face.-Case by Dr. Kenyon, of Buffalo.It began with a pimple in the middle of the forehead, where the skin had been broken by a scratch. It looked like a watery excrescence and bled when touched. The lady was of light complexion, nervous temperament, had never been sick much, no hereditary disease perceptible.

She took Thuja 6° in the morning; Thuja 30° in the evening. Next evening Thuja 200°. And afterwards one dose Sacchar.-lact. each evening. In one week it ceased bleeding, and was diminished one-half its size. In two weeks all trace of it was gone, no spot left where it had been.

Wens are considered endemical in certain regions, generally mountainous, as Switzerland, Bohemia, and the Pyrenees in Europe, and the Andes in America. Dr. Guyon publishes the history of the family of a Belgian consul, who went from Lima to Santiago, in Chili. When they had been there fifteen months, it was observed that the two daughters (aged 11 and 13) presented incipient wens growing upon their necks. The physicians of the country unanimously advised change of climate; and the mother embarked with the children for Europe. The voyage was protracted to 110 days, during which time they suffered much from sea-sickness and change of temperature in passing from the latitude of Cape Horn to the Equator. The children acquired the habit of passing their hands over their necks, and soon perceived that the tumors were visibly decreasing. When they reached Cherbourg they were half gone; and by the time they arrived at Brussels the last vestiges of the affection disappeared. It seemed to be a common prescription of the physicians of Santiago, as one known to be efficacious. Dr. Guyon says, a considerable number of Swiss emigrants, from the Valois, in 1853, settled in Algeria. Of these the most, especially the women, had wens. But they had not been a year in the country before they became aware of a considerable decrease in the size of the wens; and by the and of 1856 they had all disappeared. We suspect these wens were of a goitrous character.

Tumor of the Face, caused by Aneurism of the Arteries.—Mr. Ferguson gives a case in the Lancet for 1842-3: A lad, aged 19, had a tumor about the size of a duck's egg, on his cheek, which the surgeon supposed to be a cyst. Mr. Fergussen, of King's College Hospital, proceeded to remove it, "but was greatly astonished to find that it was supplied with numerous large vessels, and that it had many of the characteristics of the formidable disease called aneurism by anastomosis." He applied ligatures as speedily as possible, with the double object of arresting the bleeding and causing the tumor to slough away. (Practical Surgery, p. 147.)

ORDER II.-DISEASES AFFECTING EXTERNAL SUR FACES.

THE SKIN.-DERMIS.-CUTIS.

The skin, though apparently a simple membrane, is in reality composed of several different laminæ or layers, one within another. The outermost lamina is termed the scarf skin or cuticle; the second has the name among anatomists of rete mucosum. After these two are removed, we come to the outer surface of the cutis or true skin.

The application of a mild blister to the skin of a negro, for a few hours, raises the transparent gray cuticle from the layers beneath; and under it we find a clear serous fluid. On removing the scarf skin and the fluid, the surface beneath appears black. The black surface now consists of the rete-mucosum, a double membrane, the lower lamina of which is gray and transparent, and the appearance of a black web, resembling the pigmentum nigrum of the eye. The rete-mucosum gives the color to the skin; is black in the negro; white, brown, or yellowish in the European. It has been supposed that the design of Nature in giving the black skin to the negro has been to defend him against the tropical rays of the sun; and the purpose of a similar membrane behind the retina in the eye, appears to be not only that of absorbing the superfluous rays of light, but like the amalgam behind the looking-glass, it may enable the retina to reflect the rays, in order to perfect vision. In our own climate the skin becomes brown when exposed to the rays of the summer sun,―a process which seems also designed to defend the body against the access of too great external heat.

Functions of the Skin.-Regarded as a protective covering, the skin possesses the united advantages of toughness, resistance, flexibility, and elasticity. The areolar frame-work of the cutis is the part chiefly conferring these properties, but they are also due in some measure to the epidermis. These structures are thickest on all the points in which the skin is liable to come with most force and frequency into contact with external objects; thus they are thickest on the palms of the hands and soles of the feet, on the back of the trunk, and on the outer surface of the limbs; thinner on the front of the body and on the inside of the limbs.

The skin is employed in the two opposite functions of absorption and secretion. Absorption is performed by the net-work of lymphatics and the minute capillaries. Secretion is carried on at every point of the surface of the cutis; whilst the cuticle is merely a deciduous product which is constantly in course of separation from the cutis.

the principal agents in secretion are those glandular offsets from the skin which lie scattered in numberless multitndes beneath it. Thus the actual circumference of the internal surface of these secreting glands exceeds in extent the surface of the whole body; and the quantity of the waste material which it is their province to eliminate from the body is enormous. And this immense glandular structure is widely distributed over the whole external surface; and thus, more than any more compact glandular structure, it is subject to the vicissitudes of external temperature, acting upon the cutaneous blood vessels; therefore, general health would be much more frequently deranged than it is if a coördinating apparatus far within the body had not been provided in the kidneys. Thus, when the secreting function of the skin is imperfectly performed in a cold day, the kidneys arouse to an extra degree of activity, and throw off from the blood an increased quantity of the excrementitious materials, the presence of which the system can no longer tolerate.

The Sebaceous Glands of the skin are chiefly employed in the protection and health of the skin itself; and, like the sweat glands, they are widely distributed over the whole surface. On most portions of the body they are as abundant as the hairs themselves; and they are employed in eliminating from the system hydro-carbonaceous matters, which pass off in the form of an oily material which serves the purpose of lubricating the surface of the cuticle.

Finally, the skin performs the essential and important office of furnishing the surface on which is extensively expanded the peripheral extremities of the nerves of sensation, thus constituting it the organ of touch. The contact of foreign bodies is perceived as occurring at the point at which they actually strike the organ of touch, whether that point be within the sphere of operation of any other sense or not; and this perception is transmitted to the brain through the nerves as received. In general, touch is most acute in regions best suited, by their structure, for easy and diversified contact with external substances: for the power of nicely determining the position, direction, and amount of pressure upon the organ of touch is essential to the perfection of the sense. The experiences of a life-time teach the willhow to excite and check the contractions of the muscles, and to regulate their force and duration with wonderful precision. We also possess a muscular sense, through which the mind is able to appreciate the state of contraction of a muscle by impressions originating in the nerves supplied to its fibres. This power, both of recognizing and governing the muscular movements, is from our earliest infancy brought into association with the impressions derived from the organ of touch, and made subservient to the faithful performance of its function; "and the perfection to which habit brings the sense of touch is chiefly due

to an improved capacity it confers of appreciating the impressions made on the organ, in connection with the niceties of muscular movement."

Minute Cryptogamic Parasitic Plants in their Relations to Diseases of the External Surface. Nearly all the diseases to which plants are subject are the result of encroachments by parasitic mushrooms, fungi, or lichens, and every species of plant, in a diseased state, presents us with some minute specimens of this order. Wheat is infested and greatly injured by the rust-a highly-organized fungus, called by the botanist uredo linearis-and by that called smut, or uredo segetum. Blight, dry rot, and all the fungi that retard the growth of trees and plants are of this character.

The rapidity with which the fungi reproduce themselves, and spread over objects which furnish the proper food for their development, constitutes one of their most remarkable features. Some species "pass through their whole existence in a few minutes, from the invisible spore to the perfect plant."

The number of known species of fungi is so great that their number has never been estimated. Fries, the Swedish naturalist, counted two thousand species within a space equal to one-eighth of a mile square; and he also estimated ten millions of sporules "in a single individual of the reticularia-maxima, so minute as to look like smoke as they rose in the air. Webster says, in his History of Epidemics, that during the prevalence of a malignant fever in 1795, sound potatoes were destroyed in his cellar in the space of thirty-six hours. They were overrun and pervaded by the parasitical fungi which were rapidly diffused through every part. The peculiar state of the atmosphere favored the development of the germs, which were furnished from an unknown source. He also says, that during the pestilential season of 1798, "he saw a cotton garment covered with dark-gray colored spots of mildew in one night; and that such cases were then common." An instance is given in the Philosophical Transactions, in which a split melon was observed to be rapidly pervaded by "a green mould, which required only three hours to sprout, six to ripen, and produce, and let fall new seeds." The Sanitary Commission of Liverpool reported in 1844, that in the dwellings occupied by the poor, the impurity of the air was so great that "food became tainted in a single night."

When we descend to examine the vegetable productions of the smallest size, the microscope shows them in visible growth. A drop of yeast, placed in the bottom of a watch-glass, may be seen swelling up, as the tortula cerevisia unfolds itself, and exhibiting a forest of fungi, where, but a few minutes before, only a spore or two were visible.

The exact process by which the yeast-plant propagates itself is im