92. The good Effect of blowing every quarter of an Hour, with 25 Strokes each time with double Bellows, Showers of fresh Air up thro’ the Water, was, _viz._ they all continued well, and the larger of the two sick Fish recovered; but the lesser died at 4 o’clock, _viz._ at the end of nine Hours; upon each Ventilation it turned its Back upwards; but soon after the Ventilations, it constantly fell precipitate with its Head foremost, to the Bottom, and there turned Belly upwards. After 4 o’clock the ventilated Water frothed with larger Bubbles, this owing to the Slime of the Fish. The last Ventilation was at 10 at Night, when the Fish in the ventilated Water were well, and would probably have long continued so by the Salutariness of Ventilation; but that being discontinued, they were all found dead the next Morning, except one which had some small Degree of Life. 93. _June 7_, the Wind S. W. cloudy, the Thermometer at 58 Degrees, 13 live Gudgeons were put into two Gallons of fresh Pond-water in a Pail _A_; and a like Number into a Pail _B_, at 10 Minutes before 7 in the Morning. At 50 Minutes past 7, two in _B_ began to be sick; at 8, half of them came up for Air, and showed Uneasiness; at 15 Minutes past 8 two are dead; at 30 Minutes past 8, eight more turned Belly upwards; at 8 Minutes past 9, five are dead in _B_, and five more sick; at 30 Minutes past 9, seven are dead, and four sick, two well; and 30 Minutes past 10, eight are dead; at 11 two only alive, and also well, though they showed some Uneasiness by their raising their Mouth to the Surface, which they continued to do till nine, when they were taken out of the Water. Hence we see, by this, and the preceding Experiment on Dace, that one or two Fish may be kept alive many Hours longer than a greater Number can be, by means of the small Portion of fresh Air, that is continually mixing with the Water, on which it presses. 94. The Water in the Pail _A_ was ventilated from 10 Minutes before 7, to 6 in the Evening, by blowing every quarter of an Hour Showers of fresh Air up thro’ it, with 25 Strokes of the Bellows; by which means the Fish continued all well, laying quiet at the Bottom: At six we ceased to ventilate; for an Hour and half after which, there was no Signs of Sickness, after two Hours two of them showed Signs of Uneasiness; and at nine most of the Fishes turned Belly upwards, and lay at the Bottom dead or dying. By comparing this Event with that at eight in the Morning, we see there is more Air in this ventilated Water than in the Pond-water, as is probable by the Gudgeons living longer in it without Ventilation, than in the Pond-water. And accordingly the specific Gravity of unventilated Pump Well-water, was a very small Matter greater, than that of the same, after being ventilated with 100 Strokes of the Bellows, as I found by the Hydrometer; and there was nearly the same Difference between the specific Gravity of unventilated and ventilated Table Beer.