the Sulphur Wells at Harrogate. i B i 
in them ; yet I will proceed to the mention of fome other ob- 
vious experiments on the Harrogate water, in fupport of the 
fame do&rine. 
Knowing that, in the baths of Aix-la-Chapelle, fulphur is 
found flicking to the fides and top of the channel in which the 
fulphureous water is conveyed, I examined with great atten- 
tion the fides of the little ftone building which is raifed over 
the bafon of the ftrongeft well, and faw them in fome places 
of a yellowilh colour : this I thought proceeded from a fpecies 
of yellow mofs, commonly found on grit* ftone: I collected, 
however, what I could of it by brufhing the fides of the 
building, at the diftance of three or four feet from the water 
in the bafon : on putting what I had brulhed off on a hot iron, 
I found that it confifted principally of particles of grit-ftone, 
evidently however mixed with particles of fulphur.. 
Much of the fulphureous water is ufed for baths at Harro- 
gate; and for that purpofe all the four wells are frequently 
emptied into large tubs containing many gallons apiece; thefe 
eonflantly ftand at the wells, and the calks, in which the 
water is carried to the feveral houfes, are filled from them. 
On examining the infides of thefe tubs* 1 found them covered, 
as if painted, with a whitilh pellicle. I fcraped off a part of 
this pellicle : it was no longer foluble in water ; but, being put 
on a hot iron, it appeared to confift almoft wholly of fulphuiv 
Some of thefe tubs have been in ufe many years, and the ad- 
hering cruft is thick in proportion to the time they have been 
applied to the purpofe ; but the fulphur pellicle was fufficiently 
ebfervable on one which was new in the beginning of this 
feafon. The water when it is fir ft put into thefe tubsis tranf- 
parent ; when it has been expofed to the air for a few hours, it 
becomes milky; and, where the quantity is large, a. white 
cloudi 
