VOL. LXX.] PHILOSOPHICAL TKANSACTIONS. Qgg 



on the decline. It carried off a great number of inhabitants. It appeared chiefly 

 under the habit of an irregular intermittent, a bilious remitting, and a putrid 

 fever. There was scarcely a single house to be found in which there were not 

 some persons sick. The villages at a quarter of a league distance from the former 

 lake were free from it. This distemper was ascribed to the putrid exhalations of 

 this newly uncovered land; which exhalations were very offensive to the smell. 

 This was so much the more probable, as the disease abated when the stench, 

 checked by the cold, abated. I tried the air of this former lake on the spot, 

 and found it as good as that of Rotterdam; but there was a great deal of v,ind 

 that day, and no perceptible stench. However, Dr. Bicker, an eminent physi- 

 cian of that city, got me a phial filled with air of this lake, which he took from 

 a spot where he still perceived some of the former bad smell. This air proved to 

 be in reality of an inferior quality to that of the city. 



Dec. 12, being in the middle of the water between Dort and the Moordyke, 

 I found the air on what is called Holland's Diep of an inferior quality, the wea- 

 ther being remarkably dark, rainy, and windy; it was at lOQ. Dec. 13, being 

 returned to Breda, I found the air of that place at lOQ in the morning, the wea- 

 ther continuing as it was yesterday. In the afternoon it was somewhat better, 

 viz. at 1064, the weather having cleared up. Dec. 16, having returned to 

 Antwerp, I found the air of the lower part of that city at 105; and that of the 

 higher part at 104, the weather being rainy and temperate. Dec. 17, the air at 

 Antwerp was 107, the weather continuing to be nearly as it was the day before. 

 Dec. 19, being returned to Brussels, I found the air at 109, the weather being 

 rainy, windy, and rather warm. Dec. 21, the air at Brussels at ]06, the wea- 

 ther being dry and cold. Dec. 22, the air of Brussels was the same as yester- 

 day; the weather nearly the same also. Dec. 23, I arrived at Mons, and found 

 the air of that place at 104; the weather rainy and cold. Dec. 24, being near 

 Bouchain, I found the air at 104i; the weather cloudy and cold. Dec. 25, I 

 tried the air at Peronne, and found it at 102^; the weather frosty. Dec. 26, 

 being at Cuvilli, a village 4 leagues from Roye, I examined the air of that place, 

 and that which I had gathered on the road about 12 o'clock in the day-time; I 

 found them both at 103; the weather frosty. Dec. 27, the air at Senlis, and 

 that gathered in the middle of the day on the road, were both at 102^; the wea- 

 ther continued frosty. Dec. 29, being at Paris, I found the air in that capital 

 at 103; the weather frosty. Jan. 8, 178O, the air of Paris was at 100; the 

 weather very frosty. Jan. 13, the air of Paris was 98; it froze very hard. 



It appears from these experiments, that the air at sea and close to it, is in ge- 

 neral purer and fitter for animal life than the air on the land; though it seems to 

 be subject to the same inconstancy in its degree of purity with that of the land; 

 so tliat we may now with more confidence send our patients, labouring under 



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