VOL. XV.j PHILOSOPHICAL TRANSACTIONS. 137 



thin pieces of straws, leaves, &c. they were soon removed away. This vapour, 

 on the appHcation of a lighted candle or torch, did not flame or catch tire in 

 the least, as the fumes running through a boiling spring near Wigan in Lan- 

 cashire do, as noted in the Philos. Trans. N° 26; so that here we have two 

 different sorts of steams causing these boilings, yet neither of the fountains are 

 medicinal, nor so much as warm : the like is related by Varenius, near Culm, 

 and by Dr. Plott in England. There are other boiling waters, of a quite con- 

 trary temper, being actually hot to several degrees, so as to boil eggs and many 

 other things, put into them; as those near the Solfatara not far from Naples; 

 as also on the top of Mount Zebio in the Duke of Modena's territories, not 

 far from his villa near Sassolo ; and in the source of the Emperor's bath at Aix 

 la Chapelle, in the duchy of Juliers. Varenius tells us, that in Japan there 

 bursts out a boiling spring, so hot that no water can be heated so much by the 

 strongest fire; that it retains its heat three times longer than common water; 

 and that it does not flow continually, but for two hours each day ; and then 

 the force and violence of the vapours are so great, that they remove large stones, 

 and raise them to the height of 3 or 4 ells, with a noise like the explosion of a 

 great gun. 



From the foregoing history, we may take occasion to reflect a little on the 

 variety of exhalations prepared in and flying out from the vast subterraneous 

 magazines and repositories, as to their qualities and effects, some being cold 

 and dry, resembling air or wind, as those near Peroul, and in the caverns of 

 mountains, especially those of ^olus, and other hills of Italy, as also in mines; 

 others are inflammable, and of a bituminous nature, though not actually warm, 

 as those near Wigan in Lancashire; there are also many steams very hot, sul- 

 phureous, and saline, more especially those in the natural stoves, sweating vaults, 

 grots, baths, and the volcanos near Naples, Bajae, Cuma, and Puzzuolo, as 

 also in some of the subterraneous works at Rome; others there are of an arse- 

 nical and such like noxious qualities, as in the Grotta del Cane, on the bank of 

 the Lago Agnano ; in several mines, and in poisonous springs and lakes. Now 

 these various steams meeting with, and running through waters, must cause a 

 great variety of phasnomena and effects in them. 



Whether this great diversity proceeds from the various breaths of the Pyrites 

 and the lapis calcarius, whilst under their different states and changes, or fronr. 

 other effluvia, I dare not determine; however, I am convinced that sulphur is 

 sublimed from the pyrites, especially that gathered on mount ^tna, Vesuvius, 

 the solfatara, and in the stoves of S. Gennaro; for most of the stones and 

 cinders thrown out of those mighty furnaces do manifestly contain iron, as 

 appears by the magnet. As to the salt, taken by many writers to be a species 



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