( 6pq% y 
not give caufe to fufptik, that the Corpufelcs, whereof Fire 
aud Flame confiftsj are not all of the fame fize , and equally a- 
gitated, but that the interpofcd veflel keeps out the grof- 
fer particles like a ftrainerj though u lets pafs the minuteft and 
moft adive > He further offers it to coiifideration, Whether 
the Pervioufnefs of Glafs, even to the minute particles that 
pervade it , and their adhefioD to the metal they work on 
does neceflarily imply Pores confiantl^ gxt^t enough to tranf- 
mit fuch Corpufcles? Or^Whether it may oot be faid^/^^^ Glafs 
is generally of a clofer texture, than when io his Experiments 
the Pores are opened by the vehement heat of the Flame that 
beats upon it, and in that State may let pafs corpufcles too 
big topermeateGlarsinitsordinary Stater and that this pe- 
netration is much affifted by the vehcmeot agitation of tle^ 
igneous parts ^ which by the rapidnefs of their motion both 
force themfelves a paflage through the narrow Pores of the 
glafijand pierce deep enough into thofe of the included body 
to flick faft there* 
*But by all thefe Esperlmeots the Author profeffes himfelf 
not to be fo far fatisfied 3 as either to determine , whether the 
reftitude,by fomefuppofed in thePore^ of Glals as 'tis a tranf- 
pareut body, or rather in their ranks or rows,may facilitate the 
Pcrvioufn "> by him obferv'd in Glafs ^ or to conclude from 
them 5 that Ponderable parts of Flame will be able as 
well to pafs through the Pores of Mitailinveffels as thofe of^ 
Glafi. 
Haviflg given thefe Advertifements, to prevent the draw^ 
ing of unfafe confequences from his ExperimentSj he fubjoyos 
three or four i7£?r^?//^m/ that may more warily be deduced 
from them. Thtfirfi conftrmsj chat Flame may ad: as a Men* 
^Bruum 5 and make Coalitions with the bodies it works on. 
The fecond propofeth a Paradox about Calcination and Calces,^ 
The third ihzw^ that neither the Epicurean hypothefis 5 fuppo- 
fing a penetrationof the igneous particles through the Pores 
of the Glafs 5 nor the Cartefian doQ:nne^ teaching the opera^ 
tion of the fire to be performed by the vehement agitation of 
the fmall parts of the glafs 5 and by them propagated to the 
socluded bodies 5 that neither of thefej / fa/^ do feem to hit 
^hemaik* The fourth^ That bodies very fpirituous, fugi- 
tive 
