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PHYSICAL anv LITERARY. 165 
I did not think it neceflary to diverfify 
my experiments further by examining a 
great many fluids, which. are manifeftly 
of a like nature with thefe above mention- 
ed. I prefume pretty confidently, that the 
feveral {pirituous, watery, and oily fluids, 
akin to thefe already tried, will be found 
‘all of them to have fimilar effects. And, 
confidering how many fluids thefe clafles 
comprehend, and that, in thefe already 
tried, the cold produced feems to depend 
more on the volatility of the aggregate 
than on the nature of the mixt; I was 
ready to conclude, that all fluids whate- 
ver would, in evaporating, produce cold, 
But I have found a feeming exception, 
When the ball of the thermometer is moi- 
ftened with any of the foilil acids, a con- 
fiderable degree of heat is produced. It 
is however to be doubted, if this affords 
an exception, We know that thefe acids 
attract water from the air ; and alfo that 
thefe acids, mixed with water, always pro- 
duce heat: It may therefore be fuppofed, 
that the heat produced by moiftening the 
ball of the thermometer with thefe acids, 
is 
‘ 
Srey on ce, 
