of the common Air at Sea. 37 j 
December 1. Being fill at the Hague, the weather 
underwent a fudden and remarkable change. The wind 
was foutherly and ftormy; the air was become fo warm 
that upon going out of the houfe into the ftreet, I felt the 
fame fenfation as upon coming from a cold air into a room 
heated by a German ftove, I fufpedted that this fudden 
change would alter the conftitution of the atmofphere in 
point of falubrity. Having no time to make any experi- 
ment, I contented myfelf with filling fome phials with 
this air, and fending my fervant to Schevelingen to 
gather fome air clofe to the fea. 
December 2. The wind and weather remained the 
fame as yefterday. In the evening, about eight o’clock, 
when Fahrenheit’s thermometer flood at 54 0 , 1 put the 
common air to the nitrous teft, and found it at 1 16; the 
air gathered the day before at 1 1 7 ; and that gathered clofe 
to the fea at 1 15. As I had never found the common 
air near fo bad, I had fome apprehenfion that my eudio- 
meter was out of order, or that fomething was the mat- 
ter with the nitrous air. I made therefore frefh nitrous 
air, and repeated the experiment many times, but the 
refult was nearly the fame. In the mean time, I had the 
following accidental meeting. The father of the land- 
lady of the houfe having been informed by the fervant, 
that I was about fome extraordinary purfuit, of which 
Vol. LXX. D d d he 
