eleventh day of the disease, aperients, opiates, tonics, and nourishing diet should be given.

Great dyspnoea requires a blister to the chest.

The intolerable itching is best allayed by smearing the eruption with cold cream.

Various measures have been proposed, in order to prevent the pitting and disfigurement occasioned by this horrid disease. Pencilling the pustules with lunar caustic, and with tincture of iodine; opening each of them; covering the face and hands with an ointment composed of litharge and mercurial ointment; keeping the patient in perfect darkness, have each been recommended; but with very doubtful success. They should all be tried before the eruption becomes vesicular.

Prevention of Small-pox.-There are two methods-inoculation and vaccination. The first is very effectual, because it actually imparts the disease in a mild form; but it is not unattended with danger, especially from multiplying centres of contagion. The other method, termed vaccination, is now universally practised.

VACCINA, the vaccine disease, or cow-pox, is the name given to a disease attended with umbilicated vesicles, produced by inoculation, and protecting the human system from small-pox. To Dr. Jenner is due the credit of first bringing into practice this artificial mode of protecting the system. The disease was noticed first in the cow (whence its name), in which animal it appears in the form of small vesicles upon the teats. The matter taken from such vesicles is protective.

The idea at present entertained is, that this disease is variola, modified and rendered milder by passing through the system of the cow; and confirmatory of this view, is the experiment of inoculating the cow with variolous matter, and then employing some of the matter from the resulting pock;-it was found to be protective.

Symptoms, Course, &c.-A very slight inflammation at the point of puncture is seen, which soon, however, disappears. On the third day, a little red speck, slightly elevated, is noticed, which has b come a vesicle by the end of the fourth day. On the fifth, it is slightly umbilicated, and contains a clear lymph. This gradually enlarges, and on the sixth day the areola is visible; this continues to enlarge until the tenth day, when the disease is at its height. Now the pock is about one-third of an inch in diameter, elevated, umbilicated, and exhibiting a minute scab upon the surface. The areola is usually two inches or more in diameter. The scab now gradually forms, the serous liquid is replaced by pus, and about the twenty-first day the scab separates, leaving a cicatrix of a peculiar

appearance.

The constitutional symptoms, if they occur at all, appear about

the eighth to the tenth day. Sometimes there is a little fever, and swelling of the axillary glands, and occasionally a slight eruption. There is great difference in the susceptibility of persons to the vaccine disease, also, in the same person, at different times.

In relation to the degree of protection afforded by vaccination, it would appear, as the result of numerous experiments, that about one-half the vaccinated are liable to a modified form of small-pox, or varioloid, on exposure. Still, cases of varioloid, are so rarely fatal, that it may be considered as almost certainly protective, so far as danger is concerned. Some suppose that the protective influence gradually wears out from the system, and requires renewal. This idea is incorrect; for in that case, the susceptibility to varioloid ought gradually to increase, the longer the interval from the period of vaccination; whereas, the susceptibility really diminishes after the twenty-fifth year. The truth appears to be, that the original amount of protection afforded by vaccination, differs in different cases; and that there is the greatest susceptibility to varioloid between the ages of 15 and 25 years. Hence, revaccination should always be practised within these years; or, if not then, certainly at the commencement of any variolous epidemic.

VARIOLOID.

This name is applied to a modified form of small-pox, occurring in persons protected by the influence of vaccination. As already remarked, the complete protection of vaccination extends only to about one-half of those subjected to it.

There is no reason for regarding varioloid as a distinct disease. The proofs of its identity with small-pox, are the facts that it varies much in its intensity, that it is produced by the same cause-contagion; and that it is capable of producing genuine small-pox in the unprotected. In some cases, the fever alone exists; in others, only an eruption, either papular or vesicular, and most commonly in part pustular, going on to the fourth or fifth day, and then drying up. Its progress is always shorter, by several days, than variola, and it is destitute of the characteristic odour of that disease.

The treatment is the same as for mild cases of variola.

VARICELLA, OR CHICKEN-POX.

This is a contagious eruptive fever, the eruption being vesicular.

Symptoms.-Occasionally febrile symptoms may be present, but generally they are very slight, and continue from a few hours to two days, when they disappear on the occurrence of the eruption. This comes out in small red spots, which speedily become vesicular, and are often accompanied with itching. They attain maturity about

the fifth day, having become puruloid. They then commence to desiccate, the crusts falling off on the ninth or tenth day. The pocks are usually few in number, and very seldom umbilicated.

The only known cause is a specific contagion. It sometimes occurs epidemically. One attack is protective against a second one. The only disease with which it can be confounded is small-pox. Treatment. Often, nothing is required. The mildest antiphlo gistic means are sufficient.

RUBEOLA (Measles).

This is a contagious fever, accompanied with a peculiar eruption. Symptoms.-Those of an ordinary fever, with the addition of those of catarrh, such as redness and watery appearance of the eye. coryza, with frequent sneezing, hoarseness, and cough. There may also be some dyspnoea and tightness of the chest. The eruption makes its appearance on the fourth day, in the form of small circular spots, first on the face, and extending itself successively within a day or two, to the neck, chest, and limbs. In general, the small spots are succeeded by larger ones, and the final arrangement of the patches is usually in a semicircular or crescentic form. The rod tint of the eruption assumes its greatest intensity on the face on the fifth day.

The fever does not subside on the appearance of the eruption; it may even be increased, as also may be the catarrhal symptoms. The eruption is slightly elevated above the skin, and is attended often with itching, when at its height. There may also be a few papulæ or vesicles interspersed along with the regular eruption.

When the eruption is fully developed, the frequency of the pulse, heat, thirst, redness of the eyes, and coryza disappear, or are much alleviated; the nausea and vomiting also subside. About the sixth day, the watchfulness disappears, the cough and dyspnoea being the only symptoms that remain. On the third or fourth day of the eruption, the spots become pale, and gradually assume a yellow tint; and when the redness has disappeared, the epidermis becomes detached in small furfuraceous scales.

In children with a delicate skin, the eruption sometimes appears on the third day; but in those with a thick, brown skin, it may not be developed before the fifth day.

In some cases there is no catarrh; the disease is then named Rubeola sine Catarrho or French measles. Again, there may be simply a fever with catarrh but without the eruption. These forms of the disease are not certainly protective.

In measles, the mucous membranes are very apt to be affected; generally, the membrane of the trachea, bronchi, fauces, nostrils. and eyelids, is principally affected, but sometimes that of the sto

mach or bowels principally suffers, producing nausea, vomiting, or purging. At other times, the membranes of the brain are implicated, inducing convulsions, stupor, or coma. It usually gets well in uncomplicated cases.

The prognosis is unfavourable when the child is very young, when the eruption appears before the third day, or when it suddenly disappears. A leaden hue of the spots, petechiæ, or excessive dyspnoea, are also unfavourable signs. The prognosis is favourable when the gastro-pulmonary symptoms are slight, the progress of the disease is regular, and when the skin is moist after the appearance of the exanthema.

The sequela of rubeola are bronchitis, pneumonia, pleuritis, cæcocolitis, diarrhoea, and ophthalmia. The chief danger arises from the complication with pneumonia.

Causes. A specific contagion. It is said to be imparted by inoculation. Epidemic influences also operate in its production.

Treatment.-When the gastro-pulmonary symptoms are slight, the treatment merely consists in keeping the patient in a mild temperature, on spare diet, and giving gentle laxative and diaphoretic medicines. If the soreness of the throat be very troublesome, the inhalation of the vapour of warm water is useful.

As a general rule, all inflammations that precede, accompany, or follow rubeola, when severe, should be treated as though that exanthema was not present. Should pneumonia, or laryngitis, set in, the treatment according to the above rule should be on the general principles laid down for the removal or alleviation of these affections. If the eruption disappears suddenly, the treatment must depend upon the cause producing this effect. If it is induced by the sudden development or increase of an internal inflammation, the attention must necessarily be directed to the immediate subduing of the inflammatory action. If the recession depends on cold, the warm or vapour bath should be had recourse to. Diarrhoea frequently comes on during the convalescence, and if not too severe, is useful in checking a tendency to thoracic disease; should it, however, proceed too far, small doses of Dover's powder, and the occasional use of the warm bath, will be found useful. A common sequela of measles is, a short, hoarse, and barking cough, which has a great deal of the croupy sound, but is not attended wit. dyspnoea. It readily yields to counter-irritants. During convalescence, exposure to cold should be guarded against. The malignant form is treated

with stimulants both internal and external.

SCARLATINA.

This is a contagious, eruptive fever, particularly affecting the skin and mucous membrane of the throat. About the second day of the

affection, the whole surface of the body presents little red points, which are soon followed by patches of a deep scarlet colour, serrated at their edges, which become confluent, and terminate by desquamation from the fifth to the ninth day. The rash is slightly elevated above the skin, and disappears on pressure.

Scarlatina occurs under three forms-Scarlatina simplex, S. anginosa, and S. maligna.

SCARLATINA SIMPLEX.

The precursory symptoms of this form are, general debility, nausea, shiverings, followed by flushes of heat and thirst. On the second day of the febrile symptoms, little points, at first of a ht red, then becoming deeper, appear in great numbers on the face, neck, and chest. In the course of twenty-four hours, similar spots appear on the body, lips, tongue, palate, and pharynx. On the third day, most of the interstices which had been left are covered with large dotted patches, having serrated edges. In this stage the pulse is full and very frequent, the tongue is covered with a creamy coat, through which the red and elevated papillæ appear, producing a characteristic appearance of the organ. The skin is much hotter in this form of exanthema than in any other. The scarlet colour is of a deeper tint on the groins, buttocks, and folds of the joints, than in other situations.

About the fifth day, the interstices between the patches become larger, the scarlet colour less vivid, and slight desquamation takes place on the neck, temples, and chest. On the sixth day, the cha racter of the disease becomes less distinct; and on the eighth and ninth days, desquamation from the surface of the hands, feet, and the different regions of the body, takes place.

SCARLATINA ANGINOSA.

Symptoms.-This form is characterized by the accompanying inflammation of the throat; it commences with more intense fever, and a sense of stiffness of the neck and inferior maxilla. On the second day, the pharynx is inflamed, deglutition is difficult, the amyg dalæ become swollen, and the mucous membrane presents a vivid red appearance. In the S. simplex, the pharynx presents an exanthematous blush, but there is no effusion; in this form, however, a quantity of thick, viscid fluid, sometimes of a whitish-yellow colour, but more generally, caseous-like matter, is thrown out on the amyg dalæ, pharynx, and anterior pillars of the velum. During the second, third, and fourth days, symptoms of gastro-enteritis are present; the tongue is of a bright red colour; there is nausea, vomiting, diarrhoea, or constipation, dry cough, quick and vibrating pulse, and occasionally epistaxis. The eruption, which appears on the third day, is not so generally or equally distributed as in the former