It has recently been shown by B. J. Stokvis* that in fatal poisoning of dogs and rabbits by the chlorides of sodium and potassium a prominent pathological condition is "a never failing" oedema of the lungs. This seems to prove experimentally one point which I had worked out theoretically. SCARLET FEVER.-By the diagram which I present to you, it may seen that the sickness in Michigan from scarlet fever appears to follow the temperature, falling after the temperature rises in the spring, and rising after the temperature falls in the autumn, the sickness changes averaging about one month later than the temperature changes. The probable reason for this seems to me to be that the average duration of the sickness, plus the period of incubation, is more than half a month, and as the unit of time employed in the diagram is one month, the changes in the sickness appear to follow one month later than the temperature changes. If this is the correct explanation, it will appear from the diagram that the average duration of the disease is greatest in the winter months; at least the maximum sickness is shown to be in March-two months later than the lowest temperature, which would thus appear if the average duration of the sickness, plus the period of incubation, was more than one month and a half. But I have found that the curve for a non-contagious disease-bronchitis-which is also controlled by the temperature, does not lag two months behind the temperatnre at any season of the year. It would seem as if the average duration of scarlet fever in winter was longer than that of bronchitis, or, what to me is more probable, that the susceptibility to scarlet fever is greatest a certain time after exposure to the inhalation of cold dry air. The explanation seems to me to be the same as I have already stated with reference to small-pox and diphtheria, namely, the plastic exudation, thrown out in the air-passages after inhalation of cold dry air, has resulted in an accumulation of a sufficient quantity of the non-volatile salts of *Archiv für Experimentelle Pathologie und Pharmakologie, Band 21, 3d Heft. the blood; and the ulcerations which I have supposed may occur as a consequence of long-continued inhalation of cold dry air. TABLE 1.-By months for a period of 10 years, 1877-86, the relation which the sickness in Michigan from DIPHTHERIA sustained to the Average Atmos. pheric Temperature: Exhibiting the Average Atmospheric Temperature and what per cent all weekly reports received stated that diphtheria was under observation of the physicians who made the reports. (Over forty-one thousand weekly reports of sickness, and over 190,000 observations of the atmospheric temperature are represented in this table.) Av. per cent. of reports, Jan. Feb. Mar. April May June July Aug. Sept. Oct. Nov. Dec. 10 years, 1877-86 27.7 24.8 20.8 20.4 17.3 15.1 14.9 15.8 18.4 26.2 28.9 27.9 Average Tem perature, 10 years, 1877-86 20.56 23.62 29.80 44.33 56.08 65.10 70.52 68.14 61.67 50.83 36.04 26.60 TABLE 2.-By months for a period of 10 years, 1877-86, the relation which the sickness in Michigan from SCARLET FEVER sustained to the Average Atmospheric Temperature: Exhibiting the Average Atmospheric Temperature and what per cent. of all weekly reports received stated that Scarlet Fever was under observation of the physicians who made the reports. (Over fortyone thousand weekly reports of sickness, and over 190,000 observations of the atmospheric temperature are represented in this table.) Av. per cent. of reports, Jan. Feb. Mar. April May June July Aug. Sept. Oct. Nov. Dec. 10 years, 1877-86 22.3 23.5 23.9 21.6 19.6 17.0 13.7 11.8 12.5 16.0 17.3 18.1 Average Tem perature, 10 years, 1877-86 20.56 23.62 29.80 44.33 56.08 65.10 70.52 68.14 61.67 50.83 36.04 26.60 TABLE 3.-By months, for 30 years, 1845-74, the relation between the Weekly Average Number of Deaths from SMALL-Pox, and the Average Atmospheric Temperature, in London, England. Records of thirty thousand deaths are included in this table. Av. weekly No. of deaths, Jan. Feb. Mar. April May June July Aug. Sept. Oct. Nov. Dec. 30 years, 1845-74 23.00 24.00 21.60 23.75 24.50 22.40 18.00 14.25 18.00 13.00 14.50 18.20 Average Tem perature, 30 years, 1845-74 38.6 40.1 42.2 48.6 52.7 60.0 64.2 68.5 59.1 52.2 44.2 40.5 Diphtheria Average Jemperature —— Which stated that diphtheria was under the observa tion of the physicians who made reports. Over forty-one thousand weekly reports of sickness, and over 190,000 observations of the atmospheric temperature are represented in this diagram. By months for a period of 10 years, 1877-86, the rela Per cent of Reports.n Degrees Fahr Scarlet Fever. Average Temperature *Which stated that Scarlet Fever was under the observation of the physicians who made reports. Over forty-one thousand weekly reports of sickness and over i90,000 observations of the atmospherio Temperature are represented in this diagram. small-pox Average TemperatureExcept in a few months the small-box follows two months later than the temperature changes. The line representing Small-box should follow as long a time later than a line representing its controlling condition as is the average duration of the fatal cases plus the period of incubation? |