cfinoft part of ShipSj that lycs under water. And to ufe a 
very comEnon iQ&ance^Soot y 'tis koowD^that whilft the Wood 
isburoiogj the fmoak afccnds, wherein the two Volatil Salts 
arc contain'd, that coagulate one another into Sootjwhich two 
Salts may thence eafily be feparated and made vifible j and 
thefc Volatil Salts, conftituting the finoak and the footj rife fo 
long, untill the wood be quite reduced to AQies, in which the 
remaining Volatil Salts arc colliquated to a Fixt Salt, eafily to 
be wafh'tout by water. Thefe two Volatil Salts therefore af^ 
ford the matter, of which the Fixt Salt is made by nacans of 
the Fire : Whence 'tis evident, that we muftj (as really we 
do,) obtain fo much the more Fixt Salt^ the more Volatil Salt 
there was before Incineration in the Mixt Body 5 as alfa, why 
out of herbs, frefhly burnt to aflies, we get a grealer quanti- 
ty of Fixt Salt, than when they have been dryed up 5 becaufe 
the Air by its operation (which is fomcwhat advanced by tte 
moifture in the plant it fclfy diflblving the Saks,) hath robbed 
them of ihegreateft part of their Volatil Salts. Upon which 
fame account, wood decayed and mouldered away contains 
almoft no Fixt Saltj asithathalfo loft almoft all its weight/ 
Having thus (hew'd, that before Incineration there is found 
in Mixt bodies no Fixt Alcalifat Salt at all, and how the Vola- 
til Salts by calcination arc brought to f ufion and fo fixed 5 the - 
Author, further to make out the Fixation of fuch Volatil Salt?,, 
takes notice of the Mixture of Earthy parts in fuch bodies 5 
fome of which, when tbofe two Volatil Salts, thus opened by 
thcFire,^ aft on one an other^ arc con-coagulated with them. 
Which he conceives to be the cafe, when the faid two Salts be* 
ing concreted in the Kidneys, they by their afperity^ wound 
their fanguineous Veffels (whence the Nephritique pain,) and 
fo coagulate together with them the extravafatcd Bloody, 
which makes the Stone of the Kidneys reddifti 5 as the Stone 
of the Bladder is whitifli from the. mucous fubftance pf the 
bladder, therefore given it by nature, left the ftiarp Urine by 
working upon its membrans fliould caufc pain, being coagu- 
lated together. And fo he obferves^^ that the Stones concre- 
ted in the Bladder of Gall5taft bittcr,byr§afon of the Gall that 
is coaguUted. 
