268 Mr. Read’s Experiments and Observations 
examined the electric state of the air both within and without 
the bed-room a little before I went to rest, and found it posi- 
tive by the doubler. I arose at six o'clock next morning, and 
worked the doubler, and it quickly became electrified negatively. 
But as it often happens, in completing one discovery we get an 
imperfect knowledge of others, I was surprised to observe, by 
the action of the doubler, to what a great degree the air in the 
room was deprived of its insulating quality ; for although the 
doubler accumulated electricity in every revolution strong 
enough to enable me to ascertain its kind, yet its electric 
charge was conducted away almost as quickly as obtained. 
With a view to determine what happens in the upper part 
of the house, I went up into the garret, and found it close shut 
up, and the air within it was excessively hot, and in some de- 
gree noxious ; therm. 80°. After a very few turns of the re- 
volving plate, the doubler became electrified negatively : 1 
immediately set the door and windows wide open, and another 
door which opens over a bow window, to let in fresh air ; but 
the wind blowing moderately strong from the east, and the 
bow window door being at the north end, and the windows at 
the south end of the garret, made it unfavourable for an east 
wind to drive through it, therefore its electric state remained 
the same in kind after they had been opened, as when shut; 
for I examined it at several intervals of time : yet the state 
of the air became thereby considerably better to breathe in. 
These facts will appear still more extraordinary, when we 
consider that the general state of atmospheric electricity at 
the time of performing these experiments was of the po- 
sitive kind, as appeared by the doubler when placed on the 
wood hand-rail of the bow window, which is only three 
