children yearly; the mortality per million of the population of all ages being for successive quinquennial periods as follows:

5 years 1861-65. 5 years 1866-70. 5 years 1871-75. 5 years 1876-80. 5 years 1881--85.

456.6

428.4

373.2

384.8

410.2

It is specially a disease of children; 90 per cent. of the deaths being of children under five years of age: for example, of 12,013 deaths registered from this cause in 1886, the following was the age distribution :

Of the

Of the 12,013 deaths 6,090 were males, 5,923 females. different ages that make up the children under five years of age, the greatest number occur above the first and below the second year of life. The disease being practically confined to children, it would be a more accurate way of considering the mortality to state per population under five years of age, this for the five years ending 1885 is no less than than 2.844 per thousand, or 2,844 per million.

(286) Seasonal Prevalence.

Buchan and Mitchell's curve1 based upon the weekly deaths for the thirty years ending with 1874, shows a double maximum and minimum during the year, the larger maximum occurring in November, December, and January, and the smaller in May and June; the larger minimum in August, September, and October, and the smaller in February and March. The most rapid fluctuation takes place in the fall from Christmas to the middle of February, the weekly deaths falling from 42 to 21. The curve is a very steady one, the maxima and minima being well marked in each of the thirty years.

1 Op. cit.

(287) Symptoms.

There is a distinct incubation period, which exhibits but few variations, the initial fever commencing on the 12th, and the eruption appearing on the 14th day after infection. In popular language, measles commences as a violent cold, the eyes are congested and red, the mucous membranes of the nose inflamed, and there is some cough. Not unfrequently the throat is a little sore. In cases of moderate severity, there is considerable fever, temperatures of 104° and 105° being common, while in severe cases the temperature on the 5th day of illness may reach as high as 109°. The eruption fully out, the temperature falls rapidly one or two degrees above the normal standard. The eruption comes out in three crops; it makes its appearance on the third, fourth, and occasionally on the fifth day of the fever; the first crop attacks the face, twenty-four hours after the facial exanthem, the trunk is invaded, and the eruption lastly attacks the extremities. As it appears in one part of the body so it fades in the other. On the 6th or 7th day, it has vanished entirely, and there is a bran like and not very conspicuous desquamation. The eruption consists of small circular pinkish red or raspberry coloured spots; on pressing, there is no feeling of induration as in small-pox eruptions; it disappears on pressure. On looking at the arrangement of the eruption it is very commonly distributed in circinate curves. In very severe cases there may be effusions of blood beneath the skin, as in typhus; measles again is occasionally papular, and on the neck, arms, and breasts, in very young children, vesicles have been known to form. The organs of the chest are in the majority of cases more or less affected, and death when it occurs is for the most part due to pneumonia.

In the mildest cases the eruption does not occur or is so evanescent as to pass unnoticed. Here there are no elements for diagnosis, the symptoms are those of a catarrh. Possibly the "colds" so often seen among adults in times of measles epidemics, are attacks of measles without eruption. To complete the history of measles it must be mentioned that in a few instances there is a well marked eruption but no inflammation of the mucous surfaces.

(288) Etiology.

It may be stated with some confidence that measles is one of the micro-parasitic class dependent on some specific microbe. In the blood, in the capillary vessels of the skin, as well as in the catarrhal exudations, cocci and diplococci have been observed,1 but the bacteriology of measles has not been yet systematically investigated, and it is rather from analogy than from experiment that it may be presumed to be dependent on the specific microbe. The materies morbi is in the expectoration, and the cutaneous débris. Whether the other excreta are infectious is not known.

(289) Measures to be taken in Outbreaks of Measles.

The fact that measles begins as an ordinary cold, and that it is in this stage highly infectious, puts an extraordinary difficulty in the way of the hygienist. Of all diseases measles is most difficult to arrest the spread of in a household. Neither in typhus nor in small-pox, is the disease so intensely infectious in the early days, but in measles we are face to face with a fever which by the time the diagnosis has been formed has already sown its seed in all those who are susceptible of its influence, and who have been brought within striking distance. The striking distance also is probably considerable, at all events its rapid spread in schools under circumstances in which actual contact has not taken place, suggests that it travels to a greater distance through the air than the infection of typhus. Although measures of isolation will in nine cases out of ten be too late so far as the family or household is concerned, it is right to give such measures a trial, and to isolate the first cases of measles directly the affection is recognised, all excreta, whether from the kidneys, bowels, or from the mouth and nose, should be immediately disinfected or destroyed. The only practical method of dealing with rural epidemics of measles has been found to temporarily close the schools of the area infected; this it must be confessed has answered far better in country. districts where the children live in isolated communities than in large towns. Measles has not hitherto been treated in infectious

1 Keating, Phil. Med. Times, 1882. Cornil and Babes, Les Bacterics, 1885.

hospitals; to receive measles in hospitals would be a good thing in the interest of most of the patients themselves, but for the reason already given, that is the early development of infection, it is questionable whether the great expense to the community of treating the thousands of cases of measles would be compensated by corresponding advantages. Measles is one of those diseases which requires patient research to elucidate more clearly its nature. If success is attained in this direction, it may be then hoped that some satisfactory scheme of prevention may be formulated.

SCARLET FEVER (SYN. SCARLATINA).

(290) General Course of Scarlet Fever.-Incubation. Typical scarlet fever of ordinary severity is characterized by the following symptoms: On or about the fourth day after receiving

1

1 The following remarks as to the incubation period of scarlet fever, by Dr. Clement Dukes, are valuable :-"I think there is no incubation period so variously stated by different authors as that of scarlatina; I have heard it given from a few hours to twenty-eight days. Yet there is nothing more certain in my opinion than the fact that it never extends beyond a week, and rarely lasts so long. During the time that scarlet fever is prevalent it should be remembered that there is a class of sore throats-to all appearance often only simple acute tonsillitis, while at others having a membranous or sloughy appearance, and with a complete absence of eruption on the skin- occurring in those who have already had scarlatina; this kind of sore throat, however, is capable of passing on scarlatina to an individual who has not already been affected by it. Scarlatina is often spread extensively by these means; for if the patient has suffered previously from scarlatina, these sore throats are looked upon as simple non-infectious sore throats, and are consequently not carefully isolated for three or four days, as they should be. Being unrecognized therefore as centres of infection the incubation period of scarlatina is miscalculated accordingly, entailing in consequence, not only a scientific inaccuracy, but sometimes preventible disease and death. Thus A has scarlatina on June 1st, and is carefully isolated on the same day; but previous to his being isolated he infects or gives off germs which find a nidus in B's throat who has already had scarlatina, with a sore throat which appears on June 5th. B not being isolated for this goes about infecting his school-fellows for a week. Amongst others C, who has not had scarlatina, is infected by him on the last day of the week, June 12th, and on June 16th C shows symptoms of scarlatina. Here A is regarded as the source of infection of C, and his case accordingly is regarded as one of sixteen days' incubation. Again, B infects many boys, who have hitherto had scarlatina, with sore throat only, on various days, and these again others, until some one becomes infected who has not suffered from scarlatina, and in his case true scarlatina appears, perhaps on the twenty-eighth day from A's isolation. We then hear of a case of twenty-eight days' incubation of scarlatina. There is also another not sufficiently recognised source of error in estimating the period of incubation of scarlatina, e.g. Some years ago the following episode happened within my experience I had a case of scarlatina, and when a week had passed I assured the master in whose house it had occurred that no more cases would arise from this first case. However, many days after, another occurred, and at the end of a week I repeated with confidence my statement that no other cases could arise from the first

the sofern a. den sen amat mi a seces eristica zver the face and amk the empoc seen is earbest stay consists of Very minute pers and may easy be mistaken it measles especially is there 3 fen some auri and congestion of the o ajuste, but these spots gily become conduent and the erythematous bush is fed over the whole surface of the skin. leaving somely any healthy cases. On the first day of the eroptilo i afera the bead, neck, and upper part of the body; it keeps extending aucking ca the second day the rest of the trunk, and the third day the extremities. This order is not ernstant, for cases are optionally seen in which the legs are dist affected. The colour varies in diferent cases in intensity of hue. it may be a Miteter red or as dark as the colour of beetroot, în severe cases it may take a livid hue, and be mixed with petechiæ. Bouchat's test is useful in the diagnosis of the eruption. depends on the fact that the contractile power of the small vessels of the skin is much increased in scarlet fever, hence any pressure on the skin occupied by the eruption gives rise to a more or less enduring white stripe. The mucous membrane of the tongue and cheeks are affected. The papillæ of the tongue are enlarged, they stand up, salient and erect, little scarlet protuberances above a thick, creamy white fur; this appearance of the tongue has suggested to some a likeness to a strawberry, to others the prominent papillæ of the tongue of the cat, hence the term “strawberry tongue," "cat's tongue."

It

There is another rare class of cases in which the sore throat is absent or nearly so, the rash abundant, and evident, and yet the person feels fairly well. A remarkable case of this kind was communicated to the author by one of the Metropolitan Officers of Health; the case was that of a gentleman who had a perfectly

or second cases, but that we had not yet been able to trace the origin of the first case. This was repeated again several times until we had I think about five cases, all of them with an incubation period of considerably over a week.... How to interpret the facts accurately I could not, though I was convinced of the accuracy of my knowledge of the incubation of scarlet fever. However, by and by the unknown quantity was discovered. The boys went home for the holidays, and one of the parents wrote to say that he regretted his son had been allowed to come home with his hands peeling from scarlatina. This boy had never been ill for an hour, consequently no one knew any thing about his having scarlatina; throughout the whole time he had gone about infecting his school-fellows, and the only wonder is that he did not infect hundreds instead of units. . . . I strongly affirm that it is a rare thing for scarlatina to occur after the fifth day from exposure, and never after the eighth day; I know of no reliable case on record to the contrary."-Health at School, London, 1887.