Dr. Robinfon to Mr. I ay. 151 



when I intend to write to the beft Botanift, and the 

 moft .accomplifli'd Naturalift of this, or perhaps any 

 Age. 



1 . The Vapour afcending out of the Earth, anc? 

 caufing an Appearance of boiling in the Fountain o£ 

 Peroul, is not in the leaft inflammable by the Appli- 

 cation of a Torch, or Candle, which I experimented 

 feveral times y therefore 'tis of a different Kind fronj 

 that of JVigan in Lancajhire. This Vapour ruflies 

 out of the Ground fo violently in fome Places, tha: 

 I had much ado to keep a Candle lighted near it : 'Tis 

 a perfed: Subterraneous Wind, making the Water 

 (which we carried along with us) much colder thai 

 before it was put into the Holes, which we made \% 

 the adjacent Earth. . A learned Phyfician of Mont pel- 

 Her, then in company with me, oppos'd your Opinioti 

 concerning the bubbling of this Fountain, afcribiijg 

 it to a ftrange Fermentation between the Earth aiid 

 the Water 3 but I prefently convinced him, by put- 

 ting feveral Parcels of the Earth into Veflels, and 

 pouring Water upon them, for then we could rt>t 

 perceive the leaft Difturbance in the Water, whiph 

 in the Ditch itfelf was heav'd up 3 or 4 Inches per- 

 pendicular. I could not make any chymical Experi- 

 ments upon the Water itfelf, becaufe of its Scarcity 5 

 but the Inhabitants of Peroul told me, that they all 

 commonly drink of it when the Hole is full, without 

 any Alteration. I am confident the Vapour does^iot 

 impregnate the Water with any new Quality, /but 

 flies through it, juft as tho' one fliould blow into 

 Water with a Pipe. What our moft ingenious and 

 learned Country-man Mr. Lifter, of Tork, hath lately 

 writ of Mineral W aters, may (as I fancy) give fome 

 Light as to the Generation of this Subterraneoijs Air 

 at Peroul. Upon putting my Ear clofe to the Gnund, 

 I perceiv'd a great Noife in the Bowels of the Earth, 

 like unto the Hiffing of hot Iron in Water. 



i.Tfae 



