370 Mr. Read’s Experiments and Observations 
school with the doubler, and have always found it strongly 
negative ; which shewed that the aqueous or other conducting 
matter lodged in the air of the school, possessed less than 
their natural quantity of electricity ; while that of the school- 
master s parlour adjoining, having nobody in it, possessed some- 
what more than its natural quantity, it was found therefore 
positively electrified. 
July 5th, therm. 7 6°, I went to the school, and found the 
door and windows set wide open to let in cool air ; I now per- 
ceived no stench at all in the school, and thought it needless 
to try it. However the schoolmaster observed that the further 
end of the school was at all times most infected with, and 
seldom quite clear of stench. I therefore worked the doubler 
in that part of it, and after a very few turns it became electri- 
fied negatively, rather against my expectation. I then tried 
the other end of the school, which, by the door being wide 
open, was less liable to retain any noxious effluvium, and 
there the doubler gave positive electricity. After this I tried 
it in the schoolmaster’s parlour, where it was positive also. 
July 30th, I had the curiosity to .examine with the doubler 
the electrical state of the air in the wards of the Lock Hospital. 
In the tvvo small men’s wards it was found negative in every 
part. The floor of the large or long ward had been washed, 
and the boards were still wet; the windows in the east side, 
and the large one in the south end, were all open ; therefore 
there was but very little offensive smell in the south end of this 
ward, and here the doubler became electrified positively : but 
the great window in the north end of this ward being close 
shut up, caused a sensible closeness in the air, accompanied 
with a slight smell; and in this end of the ward the doubler 
