23. Tho’ when the distilling Liquor runs from the Bottom of the Worm-pipe, thro’ a long Pipe fixed to it, the Waste by the ventilating rushing Air, is not great when the Water in the Worm-tub is not hot; yet the following Precaution, if needful, may be used, in distilling by Ventilation, _viz._ to fix at the lower End of the Worm-pipe, by means of a wooden Fawcet, a small Cask for a Receiver; the Fawcet to enter the upper side of the head of the Cask, and in order to give a free Passage for the great Quantity of ventilaing Air to pass off, and withal at the same time to prevent the escaping of much moist Vapour with it, it will be proper to fix at the Bung-hole a long upright Pipe of Wood, or of any Metal. I used a Gun-barrel four Feet and a half long; through which some small Degree of moist Vapour escaped; as appeared by the Dampness of a Piece of Paper, fixed at a little Distance above the Mouth of the Gun barrel. This Vapour became visible, and much increased, when the Water in the Worm-tub was very hot; at which Time, less is distilled into the Cask-receiver; then also there is more Danger of the Spirit of Salt arising. And it was observable, that the Water in the Worm-pipe Vessel heated much sooner by Ventilation, than in the common Way of distilling. For which Reason that Water ought to be changed so much the oftener, which can easily be done at Sea. The Cocks also at the Side of the Worm-tub ought to be large, in order to let the hot Water off the faster. 24. But tho’ the Water in the Worm-tub was sooner heated by Ventilation, because a double Quantity of hot Steam passed thro’ it, more than passed thro’ it in equal Times in the common Way of distilling; yet in the usual Way of Distillation the Liquor in the Still is hotter, with equal Fire, as is evident by its aptness to boil over thro’ the Worm-pipe; whereas in the ventilating Way it did not boil over, notwithstanding a very hot Fire was purposely made for a Trial. The continual Streams of ascending fresh Air, not only in some Degree abating the Heat of the Water; but also incessantly carrying off the more rarefied Particles of the Water, which, when expanded into a repelling State, do thereby cause the overflowing Ebullition of the Water. On which Account it is probable, that less Spirit of Salt is formed and raised by Ventilation than without it. As also on account of the fresh Air ascending, not from the Bottom of the Still, where is the greatest Plenty of Salt, especially towards the latter End of each Distillation; but about three Inches from the Bottom, _viz._ principally from the many Holes at the Surface of the Air-box.