Cm') 
noufaefs oftheFifh, we re- admitted it, and upon its milling in, 
perceived the Light to be as it were revived, and increafed , thofe 
parts of theEifh, that were fcarce vi/ible before, or ihonebut 
dimly, receiving prefently their former fplendoun 
And not to leave un-profecuted the remaining part of the Ex- 
periment, which was to cry. Whether it was the Kind of the Lu- 
minous 5ody, or only the Greatnefi of the bulk^ and the FivUnef 
of Lights nd, if I may f6fpeak,theTo^«>y of the fubftanceic 
refided in,that made the difference between the Ftfh and the Wood-, 
We put part of the Eifliof another kind, that fhone much more 
faintly, than that, hitherto fpoken off, and but in feme places 5 
and by the withdrawing the Air wc made fome of the luminous 
parts difappear, and the others fo dim, as fcarce to be difeerned 5 
and yet both the one and the other regained their former light 
upon the return ofthe Ar. 
And to purfue the Experiment a little further, we put in fuch 
a piece of the firft Eifh, as though it were bright, was yet but 
thin and not confiderably great, and upon pumping out the Air, 
we found it, according to our Expectation!, quite eciipfed, though 
it recovered its L'ght upon the Ai rs re-entry. 
T Hefe , Sir, are the Experiments, 1 have lately made about Shining Bodies 
in our Engine. Adore I Would have tried , notwithfl an din# the trouble we 
found in managing the Engine in the dark, if rotten Wood had not failed us,and 
if I were not in a place, where Glafs-mens Shops are not near fo well fumifht as 
the Stationers. 
1 fcarce doubt, but thefe Experiments will occafton among the Virtuofi feve- 
ral Querefr and Conjectures, according to the differing Hypothef hs-and In - 
quifitions, to which men are inclined. And particularly *tis probable, that fome 
will make ufe of this Difcourfeto countenance their Opinion , That notveithfland- 
ing the Coldnefs (at leaf as tofenfe) of Fifhes and other Animals, there may be 
in the Heart and Bloud a Vital kind of Eire, which needs Air, as well as thofe 
E 'ires that are fen fibly hot : which may leffen the wonder, that Animals Jhould 
not be able to live when robbed of Air. And if I had noW time, / could pofsibly 
fumifh.you with fome other Trials, that feem much to favour the Comparifon, 
though, as to the Opinion it felf of a Vital flame I fhall not now tell you my 
thoughts about it . And though not only the Cartefians will perhaps draw an ar- 
gument from the pafl Phenomena in favour of their Theory of Light, but di- 
vers ethers will difeourfe upon them, and propofe further Queftions and perhaps 
Inquiries futable to their feveral Hypothefes •, yet / fhall content my felf atpre- 
fentto have faithfully delivered the Hiltorical part of thefe Apparencef, without 
making 
