tfie Validity of the Doctrine of Contagion in the Plague, 21 



swers, "The diseases of a place are in their nature, even although 

 they go under the same name, as subject to variations, as are 

 the nianners, customs, and circumstances of its inhabitants. At 

 one time in this country we liad well-marked agueish and asthenic 

 or inflammatory complaints; now we have few instances, at least 

 in London, of pure agues, and our inflammatory complaints de- 

 generate into asthenic congestions or defluxions." We have had 

 a change from nervous to l)ilious ailments, and this not founded 

 on the caprice of medical systems, but in the nature of the com- 

 plaints themselves. In Sydenham's time, whose works are full 

 of the descriptions of the epidemic fevers of London, dependent 

 on particular constitutions of the atmosphere in various years, it 

 was computed that 66,000 out of the 100,000 died in London 

 of fevers. This large proportion of fevers is now supplanted bv 

 other diseases ; and even our fevers are not of the same com- 

 plexion they were in those days, for we are strangers to the sym- 

 ptoms in them denoting their former pestilential or malignant 

 quality. But certainly, if any causes could have contributed to 

 the immunity we enjoy from tJie plague and bad fevers, they are 

 to be found in the greater cleanliness and less crowded state of 

 the inhabitants, with the widening of the streets, and the better 

 and more general construction of common sewers and drains ; to 

 which may be added the profusion of water now distributed 

 through the metropolis. There is a passage in Assalini, en emi- 

 nent surgeon, who accompanied the French in their expedition 

 to Egypt, and who has published the result of his investigations 

 on the plague, very much in point. After stating that the present 

 visitations of the plague in Egypt were unknown in the days of 

 its ancient grandeur ; and that the ruins of entire cities destroyed 

 and overwhelmed, with tlie majestic remains of monnments, in 

 part submerged and surrounded by water, afforded suflficient evi- 

 dence of the revolutions and changes which the whole surface of 

 Lower Egypt had undergone; he proceeds thus : ' At this day, 

 the lakes, the marshes, and the filthiness which one finds in the 

 cities of Lower Egypt, are the principal causes of the frequent 

 diseases to which they are sul)ject, and which can never be era- 

 dicated until we have found means to purify the atmosphere of 

 their environs. This important advantage may be obtained, by 

 draining off the waters of the lakes and filling them up ; by keep- 

 ing the cities clean, paving them ; and giving a free exit to the 

 rain water, which stagnating in different parts of these cities, be- 

 comes corrupted, and, conjoined with filths, infects the atmo- 

 sphere. By similar operations, several cities and provinces in 

 tlurope, America, and the Indies, have been rendered healthy. 

 1 have no doubt that the salnlirit*' which we enjoy at this day in 

 France and Italy, is the result of the amelioration of agriculture 



B 3 and 



