[ 2l8 ] 
jfions, when they were arrived at the fame degree of 
heat, m veiTels of equal and fimilar figures to the- 
fame freezing atmofphere ; and accurately marking 
the times in which they began to freeze, I found 
them obferving the following order : firfl alum, then 
Rochelle filt, green vitriol, fugar refined, white vi- 
triol, vitriolated tartar, Glauber’s fait, mineral fixt 
alkali, nitre, blue vitriol, volatile alkali, fal ammoniac, 
lad: of all, fea fait. Thefe experiments were repeated 
once or twice with feme attention ; yet I would not 
be thought to propofe the order in which I have- 
arranged the feveral falts, as wholly to be relied on. 
It were to be wiflied, that a fufficient number of ex- 
periments were accurately made upon this fubjedV 
fome general truths relative to metallic earths, and 
alkaline neutral falts, would probably be obtained- 
therefrom, which, however unimportant in them- 
felves, might ferve, upon fome occafion or other, as 
connedfiiig links, to extend the chain of our ideas. 
By this comparifon of equal quantities of different 
lalts dillblved in equal quantities of water, we might 
be enabled to fpeak with as much precifion, con- 
cerning the powers by which they refid congelation, 
as wc do concerning thofe by which they refill putre- 
fadion. I know not whether it may not be thought 
-too curious a remark to obferve, that the Ocean is im- 
pregnated with that fpecies of fait which refills con- 
gelation with the greatefl power, and in fuch a 
quantity as tends not to preferve entire, but to accele- 
rate the difiblution of the numberlefs animals which 
are daily dying in it. Beecher, it hath been allerted, 
was acquainted with tliis property of common fait j 
but 
