THE 



PHILOSOPHICAL TRANSACTIONS 



OF THE 



ROYAL SOCIETY OF LONDON; 



ABRIDGED. 



XI. Of the Influence of Cold on the Health of the Inhabitants of London. 

 By Wm. Heberden, Jun., M. D., F. R. S. p. 279. 



The extraordinary mildness of last Jan. (179@) compared with the unusual seve- 

 rity of the Jan. preceding, affords a peculiarly favourable opportunity of observing 

 the effect of each of these seasons contrasted with each other. For of these 2 

 successive winters, one has been the coldest, and the other the warmest, of which 

 any regular account has ever been kept in this country. Nor is this by any means 

 an idle speculation, or matter of mere curiosity; for one of the first steps towards 

 preserving the health of our fellow-creatures, is to point out the sources from which 

 diseases are to be apprehended. And what may make the present inquiry more par- 

 ticularly useful, is that the result, as I hope clearly to make appear by the fol- 

 lowing statements, is entirely contrary to the prejudices usually entertained on this 

 subject. During last Jan. 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 productive of putrid diseases, and I know not what other causes 

 of mortality. On the other hand, " a bracing cold," and " a clear frost," are fa- 

 miliar 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 on this point at least 

 unfounded. The average degrees of heat on Fahrenheit's thermometer kept in 

 London during the month of Jan. 1795, was 23° in the morning, and 29°.4 in the 

 afternoon. The average in Jan. 1796, was 43°.5 in the morning, and 50°. 1 in the 

 afternoon. A difference of above 20 degrees ! And if we turn our attention 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 5 weeks between the 31st of Dec. 1794 and the 3d of Feb. 

 1795, the whole number of burials amounted to 2823 ; and in an equal period of 

 5 weeks between the 30th of Dec. 1/95 and the 2d of Feb. 1796, to 147 1. So 

 VOL. xviii. B 



