[ 358 ] 



Whether moifture, (imply confidered, has any 

 other effect than as increafing the influence of cold, 

 is not clearly determined. But whatever doubts 

 we may entertain, concerning the moifture of the 

 atmofphere, there is no queftion that fome kinds 

 of moifture, to which perfons who labour in this 

 way are fometimes expofed, has fpecifically noxi- 

 ous qualities. 



The draining of marfhy grounds, however it may 

 in its confequences benefit the health of thofe who 

 live in the neighbourhood, has been long obferved 

 to be but an unwholfome employment for thofe who 

 work at it. Yet this is frequently a neceffary piece 

 of bufinefs for the farmer, as well as the cleanfing 

 of ditches, which is in fome meafure of the fame 

 kind, though in general lefs apt to do mifchief. 

 The moifture to which people thus employed are 

 expofed, muft not be confidered as mere humidity ; 

 but as humidity, combined with putrefying fub- 

 ftances, and capable of diffufing the effects of fuch 

 over thofe who are within a certain diftance of it. 



Marines are well known to produce diforders, 

 even over a considerable extent of country, and 

 muft of courfe be particularly liable to affect thofe 

 who break up any part of them. Putrid com- 

 plaints of various kinds may be produced by thefe 



exhalations; 



