r 2 3° ] 
to tranfmit it to the water. I alfo firfpected that 
metals were not eafily melted or calcined in inflam- 
mable, fixed, or nitrous, air, or any kind of di- 
minifhed air. None of thefe kinds of air fuffered 
any change by this operation ; nor was there any pre- 
cipitation of lime, when charcoal was heated in any 
of thefe kinds of air Handing in lime-water. 
Query. May not water impregnated with phlo- 
gifton from calcined metals, or by any other method, 
be of fome ufe in medicine ? The effedt of this im- 
pregnation is exceedingly remarkable ; but the prin- 
ciple with which it is impregnated is volatile, and 
entirely efcapes in a day or two, if the furface of 
the water be expofed to the common atmofphere. 
It Ihould feem that phlogifton is retained more 
obftinately by charcoal than it is by lead or tin ; for 
when any given quantity of air is fully faturated 
with phlogifton from charcoal, no heat that I have 
yet applied has been able to produce any more effedt 
upon it ; whereas, in the fame circumftances, lead 
and tin may ftill be calcined. The air, indeed, 
can take no more 5 but the water receives it, and the 
tides of the phial alfo receive an addition of incruft- 
ation. This is a white powdery fubftance, and well 
deferves to be examined. I fhall endeavour to do it 
at my leifure. 
. Lime-water never became turbid by the calcina- 
tion of metals over it ; but the colour, fmell, and 
tafte of the water was always changed, and the 
furface of it became covered with a yellow pellicle, 
as before. 
When this procefs was made in quickfilver, the air 
was diminifhed only one fifth 3 and upon water being 
? admitted 
