62. Milk might thus most commodiously be heated to a scalding Heat with little Fuel, fit for Ventilation, in a Vessel of a proper Depth, set in the same Manner as the Pans in a Stove, to secure it from Smoke, with Bellows fixed properly near it: (see _Fig. 3_.) By this Means there would be little Trouble or Expence in curing ill tasted Milk by Ventilation. 63. _May_ 14th, meerly to see what the Event would be, a Gallon of new Milk, just from the Cow was ventilated, for an Hour and half, which produced six Ounces of Butter; and tho’ it was ventilated half an Hour longer, yet no more Butter was made; it was whitish, wanting both the Colour and Taste of good fresh Butter. 64. I am credibly informed, that in the Places famous for making the best fresh Winter Butter, they set the Pot of Cream in warm Water, so long as till it has acquired that small Degree of Sourness, which it very soon has in warm Summer Weather, which gives it its agreeable Flavour. And in order to give it Colour, they grate a well coloured Carrot into a little Milk, which as soon as stained, is strained from the Carrot thro’ a Sive, and then mixed with the Cream. 65. It is found by Experience, that the Quantity of Cream is increased, by putting into the Milk a little warm Water in Winter, and cold in Summer; which being thereby, in some Degree thinned, the Cream is thereby more easily disintangled, so as more freely to ascend to the Surface of the Milk. 66. I ventilated three Gallons of stinking _Jessops-well_ purging Water. On first blowing, the Smell of the ascending Vapour was very offensive, which Offensiveness abated much in five Minutes: In eleven Minutes the Smell was much better: In twenty Minutes the Water seemed sweet both in Smell and Taste; and not sweeter at the End of forty-five Minutes, fifteen or twenty Minutes will probably suffice. 67. _July_ 20th three Gallons of stinking Sea-water were ventilated; in five Minutes it was much sweetened, and no ill Smell in the ascending Air, tho’ at first it was very offensive: At the End of ten Minutes it had a small Degree of ill Taste; after twenty Minutes no ill Taste or Smell. It frothed near a Foot high during Part of the Ventilation; this from the Bitumen, _&c._ 68. Some Sea-water which was made to stink with Flesh and Isinglass being put into it, was not made perfectly sweet, not even by a ventilated Distillation, and an Hour’s more Ventilation after it was distilled; so that Putrefaction with animal Substances, is not easily compleatly cured by Ventilation. 69. When the Water was 27 Inches deep in the leaden Vessel, no Air could be blown up thro’ it by the Force of the Bellows. But at 18 Inches Depth, the Air could freely be blown up in Showers thro’ the Water; when therefore it is requisite to blow up thro’ great Depths of Water, the Bellows may be worked with a Lever, as Smiths Bellows are worked.