VOL. LV.] PHILOSOPHICAL TRANSACTIONS. ^87^ 



them, expecting to have seen the bladders distended with air arising from the 

 water. But in this was disappointed. For, during those ]4 days, he never 

 could discover any air-bubbles adhering to the insides of the bottles; neither, 

 from other signs, did it appear that any elastic substance was separated from the 

 water; the bladders, all that time, remaining as empty as when first tied on. 

 Some of the water, being then poured from each of the bottles, was found to 

 sparkle more than when taken fresh from the fountain, and sooner to emit bub- 

 bles on the sides of the glasses into which it was poured; it was perfectly clear, 

 and still retained its brisk and pungent taste, to which was added a taste from the 

 bladders ; but, in all other respects, it seemed as little altered as it would have 

 been, had the bottles, which contained it, been all the while well closed with 

 corks. 



In order more fully to ascertain the facts above-mentioned, he filled 2 of those 

 long phials in which Frontiniac wine is usually kept, and 2 common quart bottles, 

 with the Pouhon water, and fitted to them bladders in manner before related; 

 excepting that the necks of the bladders were soaked in water, in order that they 

 might better adhere to the glass than they did when moistened with oil. The 

 water, thus excluded from any communication with the external air, stood 7 days 

 in a room, where it was continually kept lukewarm; the weather at that time 

 being excessively hot, the mercury then usually standing from 80 to 85 degrees 

 in Fahrenheit's thermometer. During all that time, the bladders were not dis- 

 tended by any elastic substance arising from the water thus heated, but remained 

 as empty as when tied to the vessels. The water in the 2 quart bottles, being 

 examined after it had thus stood 7 days, was clear, retained its brisk and sharp 

 taste, and seemed in nowise decompounded ; but, when poured into a glass, 

 sparkled much, like wine on the fret. After a 3d part of -the water was poured 

 from one of those bottles. It was immediately closed with the hand, and shaken 

 briskly about for -^ a min\ite; and being then suddenly opened, the air rushed 

 out of it with an explosive noise, and more than ordinary violence, driving the 

 water with great force, and dispersing it over the floor in a shower of 7 yards in 

 diameter. 



It has been shown by Mons. Mariotte, that air is imbibed, in considerable 

 quantities, by common water, and may again be separated from it, either by 

 heat, or by cold, as in congelation; or by removing from it the pressure of the 

 atmosphere, as in the exhausted receiver of an air-pump. And Dr. Shaw* relates 

 that, without any of these aids, air separates spontaneously from the mineral 

 water of Scarborough, and that in a few minutes, he collected into bladders large 

 quantities of air, from bottles of that water, after the manner attempted in the 



• See his Inquiry into the Contents, Virtues, and Uses of the Scarborough Spa waters. Part 2, 

 sect. 4. — Orig. 



