and the Mode of its Communication. 
The discovery of these extraordinary facts surprised me, and 
excited all my curiosity ; and I immediately set about investi- 
gating their cause. 
As it is well known that air adheres with considerable obsti- 
nacy to the surfaces of some solid bodies, I conceived it to be 
possible, that the particles of air in immediate contact with the 
surface of the cylindrical vessel No. 1, might in fact be so at- 
tached to the metal as to adhere to it with some considerable 
force; and, if that were the case, as confined air is known to 
constitute a very warm covering, it appeared to me to be possible, 
that the cooling of the vessel No. 1, might have been retarded by 
such an invisible covering of confined air; which covering, in 
the experiment with the vessel No. 2, had been displaced, and 
in a great measure driven away, by the colder covering, of linen, 
by which the body of the instrument was closely embraced. 
I conceived that the linen must have accelerated the cooling 
of the instrument, either by facilitating the approach of a suc- 
cession of fresh particles of cold air, or by increasing the effects 
of radiation ; and, with a view to elucidate that important point, 
the following experiments were made. 
Exper. No. 2. Removing the linen with which the instrument 
No. 2 was clothed, I now covered the sides of that instrument 
with a thin transparent coating of glue; and, when it was quite 
dry and hard, I again filled the two instruments (No. 1 and No. 2) 
with hot water, and observed the times of their cooling as before. 
Result, or time of cooling 10 degrees, reckoned from the 
50th to the 40th degree above the temperature of the air in which 
the instruments were exposed to cool. 
Instrument No. 1, sides naked 55 min. 
Instrument No. 2, sides coveredwith one coating of glue 43^ min. 
N 2 
