in another place, to point out some striking coincidences of period and symptoms.

Small-pox is a contagious phlegmasia, characterised by the presence of pustules of a peculiar description, developed generally in great numbers on all parts of the body, both preceded and accompanied by febrile symptoms, more or less severe. When the pustules are but few in number, and distinct from each other, it is called

66

discrete;" when they are in great abundance, and running into each other, "confluent "-to whichever variety, however, it belongs, its progress is the same, and it has the same marked course, which is differently divided by different authors. Dr. Gregory makes but three stages, those of incubation, maturation, and decline; while Biet and others divide its progress into incubation, invasion, eruption, suppuration, and desiccation: but as these minute

discussions can be of no importance here, I shall not enter into them.

It is very difficult to decide accurately as to the exact period of incubation, for during the earlier stage, the patient affected is in perfect health, until the febrile attack, that precedes the eruption, becomes confirmed: about fourteen days is considered the average period, varying from six to twenty.

The febrile symptoms set in ordinarily by feelings of horror, lassitude, aching pains of the limbs, irritability of feelings, and impatience of conversation, heat of skin, quickness of the pulse; tongue white, red towards the point, &c., which symptoms are all exaggerated in the confluent variety.

After three days have elapsed, a slight eruption, resembling a flea-bite, makes its appearance, first on the neck and breast; and subsequently, perhaps after twenty

four hours, similar eruptions appear on the extremities and other parts, which go on increasing in number and size.

Four or five days then elapse before the pustules arrive at the stage of suppuration, when they present a flattened surface, with a central depression.

In examining, on the second day of the eruption, the surface of the skin, we find a number of small elevations, with a red and inflamed base: at this period the papulæ, for they are scarcely perfect vesicles, have an acuminated head, which if touched by the point of a lancet, a little serosity exudes from them, and we may distinguish under the cuticle, a kind of semi-transparent lymph secreted.

On the following (third) day, the characteristic central depression takes place; which character increases as the pustules progress to a state of suppuration.

Dr. Gregory() says, the papulæ have their seat in the true skin; and upon the third or fourth day from their first appearance, are converted into vesicles, containing a thin transparent lymph. These vesicles are very curiously organised, being divided into six or eight cells, tied together in the centre, which, for several days, is depressed. This central depression, or umbilicated form of vesicle, is very characteristic of small-pox. The specific matter, or poison, is secreted by the parietes of the minute cells; and the progress of inflammation in the papulæ is denoted by the inflammatory circle called areola, which, about the fourth day, begins to surround it. As the colour of the arcola changes to a bright crimson, the lymph in the vesicle is converted into a thick opaque matter, of a white or straw colour. This distends the cells, and gra

(1) Cyclopædia of Medicine-Art. Small-pox.

dually increasing in quantity, breaks down. the central band, in consequence of which, the pustule acuminates. In favorable cases this process is usually completed in seven, or at farthest in eight days; occasionally it occupies only five or six days.

During this maturating of the vesicles, there is generally some fever present, which of course depends on the constitution of the patient, the number of pustules formed, &c.

About the fifteenth day the suppuration takes place, which is attended by what is termed the secondary fever, accompanied by a general tumefaction of the surface.

The period of suppuration continues for four or five days, when desiccation commences; the febrile and other disagreeable symptoms gradually cease, and with the exception of the cuticular deficiency, the patient is recovered.