< *8 ) 
Iron : For it is only the Iron that caufes the Red* 
tiefs of the Bricks, and can be extrafted from them 
again. Moreover, Metals are dilfolved by the Salts 
and Moifture in the Earth, and fo mix with the nu- 
tritious Juices of Vegetables j hence it may, infome 
refped, be faid, that we eat Metals with the greateft 
Part of our Food. 
Having given the ’foregoing fhort Account of the 
Produdion of Phofphorus , I (hall here fubjoin, that 
there is produced out of the Refiduum, after the 
Phofphorus is made, a particular Salt, which [ 
name Salphofphori, or Salt of Phofphorus. This 
Salt is fix’d in fome Degrees of Fire, yet it may be 
fublimed in a clofe Veffel, which other fix’d Salts can- 
not be, except they (till contain fomewhat Volatile in 
them j but this Salt hath no fuch thing in it, neither 
is it any ways Alcalick. 
How to produce this Salt, remains as much a Se- 
cret as the Phofphorus itfelfj for he that cannot 
produce this Salt will never be able to make Phof- 
phorus. 
There is fcarce any Body, out of which a Che- 
mical Operator cannot produce Water and Earth, 
Salts, or an acid Spirit, and an urinous Unduofity, 
in more or lefs Quantity, according to the Nature of 
the Body ; and where there is one of thefe, there is 
Fire to be demonftrated, but not without each other’s 
Help. The Encbeirefs of this would be too long 
for this Place, Ifhall therefore omit it here. 
From our Preparation of Phofphorus , we may 
refled upon the Fuligo , or Soot of all combuftible 
Subftances ; for it is the Phlogifon only that burns 
and produces Flame j it dwells in fulphureous Bo- 
dies, 
