ON THE NATURE AND CAUSES OF THE PHYSIOLOGICAL PHENOMENA
Authors: S. T. Speer
Journal: BMJ (1853)

THE quarterly returns of marriages, births, and deaths, con- tain mean readings of the thermometer, barometer, etc.; but, in order to estimate correctly the influence of weather upon sickness and mortality, it seems to be the extremes, which often occur within very short periods, that are required.It is generally understood, that sudden alterations in the weather are prejudicial to health; nor can there be any doubt of this fact; yet such alterations are frequently obliterated by averages and means.The means of a month or a week may come out nearly alike to those of the preceding week, or of the corresponding month of the preceding year, and yet in- clude very extensive thermometric changes, which are thus placed out of view.Every one, in his own person, is acutely sensible of a change of temperature from :50' to 24', and vice versc2.This may occur, and has occurred, without alter- ing the averages of the month more than 10 or 1 h'.In projecting a meteorological diagram, the mean curves are rounded off and depressed; whereas, what seems to be re- quired are the extreme limits and the time.I will give one or two examples of my meaning, from a manuscript meteorological journal now before me, embracing observations nmade four times a (day.It is at night, when going to bed, and in the morning, when we first encounter the outward air, that sudden changes in the weather are most acutely experienced.Let us take, then, .)o'clock A.M. for our illustration.On the (;th of .Janury, 183;5, at 9 in the morning, the thermometer out of doors stood at 340 F.; on the 7th, at 270; on the 8th, at 24°; on the 9th, at 40'; on the 11th, at 480: the barometer fillincr, in the same interval of time, eight-tenths of an inch.Turning to the bills of mortality for the metropolis, to find the effect, if any, of this sudden change, we find, in the week ending January 6th, the deaths from scarlet fcver, 7; from measles, 15t; and from hoopin-cough, 15; whereas, in the week ending the 23rd (when the influence of the vicissitudes of temperature between.the 7tlh and 11th of the month might be expected to appear in the mortality table) we in(l the deaths from scarlet-fever, 14; from measles, 23; and from hooping-cough, 18.In the two former instances, the mortality wasl doubled.The inference is, that cases of sickness were both aggravated and largely increased.Again, in April 1.835, we meet with another remarkable example of a sudden depression and rise of temperature, and of the dew-point, as ascertained by Daniell's hygrometer.Ott the 14th of the month, the dew-point, at 9 A.M., was ,500; on the 16th, at the same hour, it was 250; on the 17th, 28; and on the 18th, 420.The thermometer, in the same period, ranged from 610 on the 14th to 28' in the night of the 16th-a range of 33'.Turning again to the bills of mortality, we find, in the week ending the 28th April, an increase in the burials, as compasred with the preceding week, of 332.The deaths from consumption were double: fever, scarlet-fever, mea- sles, hooping-cough, and inflammation, being the other heads under which there was a large increase.April we expect to be a month of genial, warm, moist, spring weather; but, as above shown, it is subject, for 24 or 48 hours, to a temperature and a dew-point appropriate I0m OA--ORGIA COMUNIATINS *nt individuals.