132 OF ORES AND COALS. 



The eruptions at Fenham were in near twenty places. I have not 

 heard that it caft forth ftones of any confiderable magnitude. 

 Flowers of fulphur, mixed with fal ammoniac, were found con- 

 creted on pieces of alum-flone, flate, and the neighbouring furz, 

 of which a phyflcian of Ne-wcqftle upon Tyne, Dr. Hodgfon, gave 

 an account to the Royal Society (IJ, who could difcover neither 

 common fait or nitre in the foil or fprings about it, the coal- 

 water being all vitrioline, and tinging red with galls, and other 

 neighbouring fountains being deftitute of mineral falts. But he 

 obferved, that the coal-ways were mended with a fort of flate, 

 compofed of coal, alum-flone, and mareafite, caft in heaps and 

 burnt, from which he had often collected both brimftone and fal 

 ammoniac. 



Some of the fait ejected by this bitumenous vulcano was, up- 

 wards of fix inches broad. It was firfl obferved and gathered by 

 Dr. Richard Gilpin, in whofe company Dr. Hodgfon proved it by 

 an experiment to be fal ammoniac. For colour, fome of it was 

 grey, fome fnow- white, freed from the black f&tor of the coal by 

 the intenfe heat of the fire. 



Factitious, fulphurous air collected from the folution of me- 

 tal at the time of their effervefcence, efpecially iron, 3!) of filings 

 being mixed with 3!) of oil of vitriol, and gviij of common water, 

 will exhibit the lame phenomenon on trial after the fame man- 

 ner as the fulminating damp, and if the flame of the candle is 

 fuflered to enter the neck of the bladder, the inclofed air will 

 take fire, and go off like a gun with a great explofion. 



Dr. Broivnrigg, an eminent phyfician at Whitehaven, drew up 

 a hiftory of damps, which was communicated to the Royal So- 



(k) Ph. Tr. No. 130. 



ciety 



