DELIQUESCENCE OF BODIES, 
Experiment here perfectly agrees with theory j bat in order 
to shew manifestly the deliquescence in such other bodies as 
are also weakly deliquescent, a small separate portion of each 
must be taken. These will be completely melted, whereas 
larger crystals would simply become moist, or liquify very 
slowly. 
It is easy to conceive that it must be important to attend to The tempera- 
the temperature $ for as heat greatly favours the combination of Ireat conse- 
salts with water, the boiling point of each solution must vary quence. 
according to the temperature at which that solution was made. 
Thus nitre, which is weakly deliquescent at 15 ' and of which 
the saturated solution boils at 101 ,4 would be very deliquescent 
at the temperature of 100°, because its saturated solution made 
at that temperature would not boil short of 1 10 or 1 12°. 
The acetate of lead, and corrosive sublimate, do not sensibly Salts not 
raise the degree of tire boiling point, and accordingly they are deliquescent, 
not at all deliquescent. 
In determining the degree of ebullition of saline or acid Remarkable 
liquors, I have observed a very singular phenomenon which ? ac } : that the 
. . . T . . I , , bowline nonit 
deserves to be known. It consists m the tact, that water and G f water j s 
other liquids boil later in a glass vessel than in a metallic vessel, different in 
unless the filings of iron, copper, or some other metal, or ^etalhe 
charcoal powder, or pounded glass be mixed with it. The vessels. 
difference of temperature with regard to water, is as much as 
1°,3 (nearly 2° K.) and sometimes even more. This fact is of 
great importance in the graduation of thermometers, between 
which such a difference might exist in instruments made with 
the same care, provided the upper point of the one were taken 
in a glass vessel, and that of the other in a metallic vessed. It 
is true that if attention be paid, not to plunge the ball of the 
thermometers in water the difference will be less*. 
I have likewise ascertained that there is no salt which sa;: 
depresses the 
possesses the property of lowering the boiling point of water, boiling point 
though Mr. Achard has asserted the contrary. °* watej ’* 
When we have ascertained the degree of ebullition peculiar point'ot' 
to each saline solution, by means of which we acquire a deliquescence 
determinable 
by inclosing 
„ „ . the instrument 
* The method prescribed by the Committee or the Royal society, nnc j or gj ass 
that the boiling point should be taken in steam, would remove this wetted with 
yrobabty apparent irregularity. N. the solution. 
measure 
