Two Objervdtions made by P. Francefco Lan^, the Attthr of the 
*Sf6ktn9f 'm Pfodromus premifed to Arte Maeftra * , C9ncerning 
Numb, i^n Jome of the effeffs of the Burning Concave of Lions ^ 
and alfo an odd Salt extraUed out of a Metallie fub- 
fiance ; Taken out of the fame Venetian JournaU 
THe jirjt i$5 That the faid Fk Lana having been inform'd, 
that that famous Burning ConCave, not long fincc made 
by M. de Ftlette ^ did much foofier melt Iron, than Gold or 
Silver; he efteems it worth cdnfiderifjg, why a Kitchin-fire 
doth the contrary, melting G old fooncr than Iron ? Whether 
it proceeds thence, that the Aftral heat of the Sun is dryer 
than oUr common 6re , having much humidify in it 3 whence 
Gold being raoifter than Iron, tnaymorerefift the dry ccle- 
ftial heat of the Siiiij, than Iron afid the reft of the dryer Met- 
ralscando? Or, Whether Gold, being of afl Mettals we 
know of, the longeft a producing ^fid perfcdlitig by the Solar 
heat^ fo 'cis alfo longeft a diflblving by the fame ? 
The other is, that the faid P. Lana^ having ejetrafted out of 
a Metallic Subftance a very white Salt, the fame was, upon 
the application of the gentleft heat, refolved into a GoMen- 
colour'd liquor ; which being reitioved froto that warmth, as 
foobas it felt the cool Air, and even by opening the Glafs 
wherein it was inclofed, did in a moment flioot afrefli into the 
fame Salc5and that (which fecm'd oddeft) whilft he was pour- 
ing it out of one glafs into another during its fluidity, it was 
difperfed all over the glafs it was poured into , fuddenly con- 
gealing into moft fifte threds, many of whitih were extended 
from one fide of the glafs to the other, aHd,hanging as twere 
in the Air, formed juft like the fubtileft Cob-webs, not at all 
rigid, but, by reafon of their cxquifite fubtlety , pliable^and 
fcarce perceivable by the Eye. 
Be 
