'Tis a good Symptom that we are got upon a right Scent, when it leads not only to the Thing first sought for; but also to many other useful Discoveri… - Stephen Hales

Having procured some Norway or Swedish Tar which was thirty Years old... I, according to the Bishop's Prescription, made Tar-water in the proportion of a Gallon of Water to a Quart of Tar, stirring it four Minutes: I then took a Pint of this Tar-water, and evaporated it away in a , cut to a wide Orifice... and weighed.

A Translation of which ingenious Treatise, was communicated to me by Dr. Mortimer; in which he says, "In Hospitals and Barracks for the Sick, this Machine is placed in the , from whence two or three Pipes go down, some Inches thro' the Ceiling, into each Room where the Sick lie; and thus draw out all the unwholesome Air and Stench, which does more harm than any Physick can repair. And at the same time, has this accidental Benefit, That those who begin to mend, may give themselves a proper Exercise, in working the Machine: Only they ought to take care to keep all the Garret-Windows open, while the Machine is a going. In Men of War and Hospital-Ships, this Machine is placed on the upper Deck, directly over the great other Hatch: And then the Pipe, which goes down between the Decks, draws out the unwholesome Air; which is instantly supplied by fresh.

I was at first much discouraged, when I reflected on my Rashness, in venturing on an Undertaking, which had baffled the repeated Attempts of the best Philosophers and Chymists, both Ancient and Modern: In so much that they looked upon it as almost impracticable to find out any way to procure a wholesome Drink from Sea-Water.