OF PHLOGISTON, 



35 



I mixed a quantity of this fubftance pounded with 

 pounded finery cinder ; and putting it into a gun barrel, 

 got from it fixed air as copioufly as if a ftream of water 

 had pafled over it. There was a confiderable refiduum, 

 which was inflammable air from the iron. 



7. Dr. Woodhoufe obferves that if the manganeze be 

 heated in inflammable air, and much of the air difap- 

 pear, the metal is not revived. But not only may the 

 calces of metals imbibe much phlogifton before their 

 complete revival in a metallic form, but other fubflances 

 alfo appear to do the fame. After heating calcined alum 

 in inflammable air, it became black, and the air was di- 

 minilhed one-fifth. The infide of the veflTel in which 

 the procefs was made had alfo a black coating. And 

 brick, which contains iron ore, becomes black in the 

 fame circumftances ; but it is not even attracted by a 

 magnet afterwards. Pounded flint glafs becomes black, 

 and abforbs inflammable air, when it is melted in it with 

 a burning lens ; but no lead is formed. 



8. I have obferved that when a mixture of dephlogif- 

 ticated and inflammable air is exploded, acid is produced 

 if there be any excefs of the dephlogifticated air, but only 

 •water •with phlogijlicated air if there be any excefs of the 

 inflammable air. Thefe proportions I endeavoured to 

 afcertain, and I found that acid is formed when 100 

 meafures of inflammable air are united to 5 1 meafures of 

 dephlogifl;icated air ; but that only water was produced 

 when 100 meafures of inflammable air were imited to 

 47 meafures of dephlogifliicated air. 



E 2 No. 



