[ t 38 ] 
and flrong, as they did before the waters were ex- 
pofed to the air. 
The third day the lower water appeared clear and 
colourlefs as before, only its furface was covered with 
a few fmall fpots of cremor. The upper water ap- 
peared more yellowifh than formerly, and its furface 
was almoft wholly covered over with the cremor. 
They both afforded a tincture with galls, which was 
not fenfibly different from what they gave before 
their expofure. 
On the fourteenth day the water of the under 
well had precipitated a yellow ochrous fediment, but 
the other water a more confiderable quantity. A 
large quantity of cremor continued alfo to fwim upon 
the furface of the upper water, but there was very 
little feparated from the water of the under well. 
Both waters being now tried with galls, inftead of 
the deep blue colour, which they did formerly ex- 
hibit, they now became only of a deep purple 
colour. 
On the twentieth day the vifible appearance of 
both waters was the fame as when laid obferved. 
On the thirty- eighth day they both afforded as 
deep a purple colour with galls, as they did three 
weeks before ; and during that time alfo they had 
not precipitated any more of their ochrous parts, nor 
fuffered any other fenfible alteration. 
The water of the upper well being filtrated from 
all the ferrugineous matter, which it had feparated 
during thefe thirty-eight days, was rendered almoft 
as limpid and clear as when newly taken from the 
well : but, being boiled for fome time, it became of 
a turbid yellow colour 5 and being allowed to ftand, 
it 
