[ ^7 ] 
Experiment XIV. 
After the firft reparation of the ochry fediment, the 
water continues clear, and tranfparent ; and notwith- 
standing I have kept fome bottles half full, months, 
and years, yet the water preferved its purity, and 
would in a lefier degree turn purple with galls. 
Experiment XV. 
The water being filtred from the ochre, which was 
precipitated at the bottom of the bottle, and then 
put on the fire, emits many air bubbles, then 
grows turbid and yellow, and after a little evapora- 
tion throws up a thick fcum, which Separated by 
filtration proves to be a fine ochre befet with felenites. 
The water will then, after boiling, turn purple with 
galls. By accident I let fall fome hot Somerlham 
water on an iron fender, which it inftantly turned 
to fo many blue Spots, as there were drops on the 
fender. 
Experiment XVI. 
After this Second filtration, the water appears 
greenifh at the top, and lets fall a white fediment ; 
when the liquor is evaporated to nearly the quantity 
of half an ounce, a thick pellicle is formed. 
Experiment XVII. 
If to this refiduum a Small quantity of diftilled 
rain water be added warm, and then filtred, a very 
Vol. LVI. D white 
