82 EFFLORESCING PROPERTIES 
Nov. 
6 56.1 grains. 
11 16 
14. 78.6 —— 
Weight gained.| Nov. |Weight gained. 
16 78.6 gained. 
21 78.6 
I left it exposed to the atmosphere till the 4th. 
December, when I found it to be of the same 
weight as on the 21st. November. It was there- 
fore evident that more water could not be ab- 
sorbed. 
Now, the 78.6 grains of water absorbed are 
only 1.4 grains short of being equivalent to ten 
atoms,* and it is probable that a waste of that 
quantity of salt may have been made in the numer- 
ous weighings. If this be granted, I am right in 
concluding that the anhydrous carbonate ac- 
quires water until it is of the same constitution 
as the erystallized carbonate, if exposed to such 
an atmosphere as I have made use of,—one 
(as will be perceived by the register) whose 
temperature ranges from 53° to 43°, and whose 
vapour point is not more than 7° below the tem- 
perature nor less than 5°. 
In Dr. Dalton’s new system of Chemical: Phi- 
* Or 2.1 gr. short of what, from the result of a subsequent 
experiment which I shall hereafter mention, I should have 
expected the gain to have been. 
