470 Mr. Wilson’s Account of a mojt 
Thofe gentlemen whofe opportunities have led them 
to know how far the philofophy of heat hath, of late 
times, been extended by the great difcoveries of Dr. 
black, Dr. Irvine, and Dr. crawford, will be mod: 
interefted in the views which offer from the foregoing 
experiments. If at firft fight there appears any thing ad- 
verfe to certain general principles already eftablifhed, 
yet we may reft fatisfied that this is but in appearance 
only ; as the perfect method of induction, purfued by 
thefe philofophers, leaves no room to apprehend that 
any future difcovery will militate againft their conclu- 
fions. In the further profecution of this fubject, and in 
whatever way it may be cleared up, it is probable, that 
we fhall meet with a fine inftancc of the congruity of 
nature in all her operations, and of the liability of thofe 
general laws,, which have been derived from a cautious 
obfervance of the rules of the experimental philofophy,. 
l am, 8cc,. 
The following obfervations which relate to the difpo- 
fition of the air in giving out hoar-froft may be here 
fubjoined. 
It would be going too far were we to conclude from 
the experiments related above, “ that very cold air is 
« 
never 
