In the Year 1740, I wrote to Dr. Martin Physician to Lord Cathcart, General of the Forces which lay imbarked at Spithead, for an Expedition in Americ… - Stephen Hales

This Acid in Tar-water will curdle Milk; yet Turpentine-water will not... which shows that Tar is considerably acidulated, by the action of Fire in making.

We have seen in the Course of these Experiments, the Quantity of Tar that there is in Tar-Water; and the great Difference of that Quantity, made with different kinds of Tar, and different Degrees of Stirring. Now, since, notwithstanding these Quantities of Tar, and the additional more subtile volatile Oil, which flies off in Evaporation, it has yet undoubtedly proved an efficacious Remedy in many Cases and Instances; it may hence be reasonably concluded, that the Medicinal Virtue of the Water does not reside solely in the Acid, but partly also in the unctuous oily Parts, which are so temper'd by the Acid, as in some Cases to prevent their heating too much.

Johannes Gadesden [i.e.,] Johannes Anglicus, Anno 1516, says that Sea-Water may be sweetened four ways, viz. by filtrating thro' Sand: By clean Linnen laid over a Boiler, and squeesing the Moisture out, as from the Sponges: By Distillation: As alfo by thin Bowls made of white Virgin Wax, which 'tis said will free the Water from its Saltness, and from some part of its nauseous Bitter. But this is only a matter of curiosity, because but a very small Quantity can be thus prepared; and in order to make those waxen Bowls fit for farther Filtration, they must be cleansed from the Salt, by being washed in fresh Water.