Until lately it was believed that the atmospheric gases dissolved in sea-water could be extracted from it, as from fresh water, by boiling in
vacuo
. The merit of the discovery that such is not the case is due to Dr. Jacobsen, of Kiel, who found that, in order to drive out the whole of the carbonic acid, the water must be evaporated almost to dryness, and that no amount of boiling
in vacuo
will suffice to eliminate it. Being particularly interested in the matter, I immediately commenced a series of experiments to determine, if possible, the salt or salts to which sea-water owes this property. Preliminary observations satisfied me, in the first place, that sea-water has this property, and, secondly, that solutions of the sulphates of magnesia and of lime possess the same property. In order to gain more precise information, two series of experiments were made, the one analytical, the other synthetical. The former consisted in saturating saline solutions with carbonic acid, and then distilling them, the carbonic acid passing in the various fractions being determined; the latter, in determining the absorption coefficients of two solutions, the one of sulphate of magnesia, the other of sulphate of lime.
I. On the absorption of carbonic acid by saline solutions