[ 2i6 ] 
be colder than in its progrefs from a northern ; and 
as to the other opinion, the pha?nomenon of the 
cold’s increafing upon the wind’s changing from 
north to louth, hath been taken notice of in other 
places, where there was no fnow to refer it to. May 
it not deferve to be confidered, whether the fudden 
folution of large quantities of aqueous vapours, brought 
from the fouth into a dry northern air, be not a 
caufe adequate to the’effedt produced ? The folubili- 
ty of water in air is diftind:ly mentioned by Dr. 
Halley, in the Philof. Tranf. N° 192; and in the 
6th Vol. of the French Encyclopedic, publifhed in 
1756; and more fully and ingenioully treated of by 
Dr. Hamilton in 1765 : the cold attending the fo- 
lution is a phaenomenon fimilar to 'that attending 
many other chemical folutions, and is in a lefs de- 
gree fenfibly felt by every one who goes into a room 
newly wallied, or flreet in the fummer time lately 
watered. 
Upon taking the thermometer out of the river, 
its bulb was quickly covered with a thin cruft of ice, 
which defended it fo much from the cold fubfifting 
in the atmofphere, that it did not fink two degrees 
in ten minutes ; whereas, when it was wiped dry 
after immerfion in water, it funk above 20° in a 
lefs fpace of time: this circumftance fhews that ice 
doth not tranfmit cold, and is explained by the ex- 
periments of M. Richmann, who hath eftabliftied 
it as a principle, that metallic fubftances are far more 
quickly afteded in their dimenfions by the tranfitions 
from heat to cold, and the contrary, than any other 
bodies yet known. 
7 
Being 
