[ 23° ] 



to tranfmit it to the water, I alfo fufpected 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 ftanding 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 effect 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 mould feem that phlogifton is retained more 

 obftinately by charcoal than it is by lead or tin j 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 effect 

 upon it $ whereas, in the fame circumftances, lead 

 and tin may ftill be calcined. The air, indeed, 

 can take no more ; but the water receives it, and the 

 fides of the phial alfo receive an addition of incruft- 

 ation. This is a white powdery fubftance, and well 

 deferves to be examined. I mall 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 

 Surface of it became covered with a yellow pellicle, 

 as before. 



When this procefs was made in quickfilver, the air 

 >was diminimed only one fifth -, and upon water being 



3 admitted 



