As is well known scarlet fever tends to recur at regular intervals. The last epidemic was in 1887-8; the one before that was an exceedingly mild one in 1885, and the one before that, a very severe one, in 1879-1880. During the first ten months of 1890 there were very few cases of scarlet fever, and, in fact, for the whole year the number of cases was less than it has been in any year since reports have been required. Nevertheless as three years have elapsed since the last epidemic, and as neither that or the preceding were very extensive, it seemed quite probable that there might be a recurrence of the disease in the fall of this year. Therefore the increase which was noted in the latter part of November and December was not unexpected. The disease, however, was exceedingly mild, and was in many instances so little characteristic as regards its onset, the character of the eruption and the slight desquamation, that the diagnosis was considered doubtful by the attending physician. But there were enough typical cases to make it clear in my own mind that we had to do with true scarlet fever though in an exceedingly mild form. This opinion, I think, was shared by the majority of physicians. During November and December only 3 deaths were reported among 56 cases. In very many instances the initial symptoms, including the sore throat, were very slight, the eruption not at all well marked, and the desquamation far from copious and entirely completed within two weeks. This being the character of the disease, it was not recognized by the attending physician in some cases, and in some no physician was called. In doubtful cases the family often feel aggrieved if the physician reports to me, but this he is required to do by law, and I am always ready in such instances to be called upon to assume the responsibility of establishing the diagnosis, not that advice may be needed by the attending physician, but that a public officer rather than the medical attendant may bear the ill-feeling on the part of the family, which sometimes exists.

The following table gives the results of my observations during the past four years, concerning certain points in the etiology and prevention of scarlet fever. This table does not include all the families and cases, as a considerable number pass from observation through removals or otherwise. But a large proportion ard a fair average are represented :

Number of these in which there was a second case....... 130
Number of susceptible children in all the above families.. 986
Number of these children who were attacked........

452

The figures for 1890 do not differ in any marked degree from those of preceding years. There was, perhaps, slightly less tendency for the disease to spread in 1888 and 1889 than in the preceding two years, but the figures are too small to be of much value, and it would be a question whether such improvement should be attributed to greater precautions, or to a milder form of the disease. The question of the value of inunction and disinfection is of much interest. As in previous years inunction as practiced here does not seem to be of any value in restricting the disease to the initial case. As regards disinfection, the disease is not more than half as liable to spread beyond the first family to others in the house where disinfection is done as where it is not done. It is to be noted that during the last year the disease has been confined to the family where it first appeared in every case in which the rooms were disinfected by this department, and that it is during this period that steam disinfection as well as sulphur fumigation has been employed. But as persons who ask for disinfection are apt to be especially careful in all other respects, it is unsafe to attribute too much to the disinfection. This is particularly to be remembered in view of the unsatisfactory nature of the disinfection which will be referred to in another place.

The following table shows the number and percentage of persons of different ages exposed to scarlet fever who contracted it and also the number who did not. When I began to collect these facts the inspector was not careful to obtain the age in every case, so that until 1890 only a portion of the cases are contained in the table:

The number of deaths from this disease in 1890 was slightly less than in the preceding year, but the number of cases was almost the same. The number of cases, however, is not determined as accurately as in scarlet fever, for the diagnosis of diphtheria cannot be made with such certainty as in the latter disease. The following table on page 120 shows the cases and deaths from diphtheria for each month during the last six years, and the ratio of deaths to cases during the last seven years.

The table on page 121 shows the number and percentage of persons of different ages exposed to diphtheria who contracted it and also the number who did not.