280 Dr. Heberden Jun. on the Influence of Cold 
During last January, nothing was more common than to 
hear expressions of the unseasonableness of the weather; and 
fears lest the want of the usual degree of cold, should be pro- 
ductive of putrid diseases, and I know not what other causes 
of mortality. On the other hand, “ a bracing cold,” and “ a 
clear frost,” are familiar in the mouth of every Englishman ; 
and what he is taught to wish for, as among the greatest 
promoters of health and vigour. 
Whatever deference be due to received opinions, it appears to 
me however from the strongest evidence, that the prejudices 
of the world are upon this point at least unfounded. The 
average degrees of heat upon Fahrenheit's thermometer 
kept in London during the month of January 1795, was 2 3 0 in the 
morning, and 29°. 4* in the afternoon. The average in January 
17 96, was 43°-5 in the morning, and 50°.i in the afternoon. A 
difference of above twenty degrees ! And if we turn our atten- 
tion from the comparative coldness of these months, to the 
corresponding healthiness of each, collected from the weekly 
bills of mortality, we shall find the result no less remarkable. 
For in five weeks between the 31st of December 1794 and 
the 3d of February 1795, the whole number of burials 
amounted to 2823 ; and in an equal period of five weeks 
between the 30th of December 1795 and the 2d of February 
1796, to 1471. So that the excess of the mortality in January 
1795 above that of January 1796, was not less than of 1352 
persons. A number sufficient surely to awaken the attention 
of the most prejudiced admirers of a frosty winter. And 
though I have only stated the evidence of two years, the same 
conclusion may universally be drawn ; as I have learned from 
a careful examination of the weekly bills of mortality for 
