( 609 ) 
fcytheCold, and to have no light, that lconlddifcern m a 
place dark enough. And for fear , that this effeft may have 
proceeded not barely from the operation of the Cold , but 
alfo from that of the Salt (for which fufpicion you would 
fee reafon enough , if I could fti^w you my Trials about 
Shining Fifh.) I caufed another time a piece of Whiting to be 
put in a Pipe of Glafs fell’d at one end , and- having feen it 
{hue there, 1 lookt upon it again, after it had flayed but a 
quarter of an hour , by my eftimate , in. t frigorifick mix- 
ture which the Glafs kept from touching the Fifh 3 and yet 
neither I , nor a Youth , that I employed to look on it , could 
perceive in a dark place , that it retain’d any light $ which' 
whether the Cold had deprived it of by that great change of 
Texture, that the Congelation of the Aqueous Juyce of the 
Fifh (which I have feveral times obferved to be luminous) may 
befuppofed to have made in the Body invaded by it 3 ^ whe- 
ther the effed depend more principally on feme other caufe, 1. 
ftull not now examine. 
Differences, 
I, T he fir (l difference I obferved betwixt a, Live Coal and 
Shining Wood , 'k, that, whereas the light of the former is 
readily extinguifhable by Compr effort fas is obvious in the pra- 
Bice of fuddenly extingmfhng a piece of Coal by treading upon' 
it ) X cojtld not f nd that finch a Compr ef ion > ns I could c stive ■* 
niently give , without lofing fight of its operation would put ouP 
or much injure the light ev n of f mad fragments of Shining: 
Wood r One of my Trials about which I find thus fet down a- 
mong my Notes about Lig hr, 
I took a piece of Shining Wood , and having preft it be- 
tween two pieces of dear Glafs ( whereof the one was pret- 
ty flat , and the other convex ) fo that L could clearly fee 
the Wood through the , Glafs , I could not perceive , that 
the compreffion , chough it fometimes broke the Wood in- 
to feveral fragments 3 did either deftroy or confiderably alter 
the Light, 
This -Experiment I repeated , with the fame fuccefs, But P , 
