Part IV. And 3 \[atural Philtfophy, 357 
correfpond with all thofe experiments 3 and will be too long 
to fuit with this Catalogue. 
I fhall here only fay, I am inclined to believe, That, in 
this Cafe, all the three Bodies above mention’d ferve toge¬ 
ther to compofe an Apt Recipient of that which is the 
true Luminous Body. That, as in the mixture of Sulphur 
and Water , fulphurious Salts , of affinity with both, are 
ufed as a medium: fo here, the Cretaceous Parts ferve to 
fix the Nitrous 5 and the Nitrous, to fix the Igneous 3 being 
of a middle nature and readily incorporated with them 
both. And being in this union expofed to the Sun Beams, 
or other Light, the Igneous parts ferve,for feme time, to re¬ 
tain a certain portion of fuch as are Luminous, or to give, 
as I may fay, a degree of Fixation to Thefe alfo: and that 
therefore this Mixture is kindled or made to fhine,by puting 
it into the Light,as a flick is made to burn, by puting it into 
the fire. 
* Of fhining Flefh, fee a Relation of forne Remarkable 
Circumftances, made by Dr. J. Beal, and published in the 
Phil. Tranf. (a) CAN. 125, 
Of Inflruments relating to fj\fatural Philofophy. 
A N AIRE-PUMP 3 or an Engine to exhauft the Air out 
of any YelTel fitly applied.Contrived and defenbed (b) <A) Expert, 
by the Honourable Rob. Boyle Efq,. Who hath alfo made 
therewith, and publifhed in feveral Tracts, a great variety >yk of the 
of accurate and inft rue five Experiments. t S h p "^. of 
A Great CONDENSING ENGINE of Brafs 3 con¬ 
trived to ram and crowd a great quantity of Air into a 
little room. Whereto is alfo fitted an Iron Gun or 
Barrel. 
A Little CONDENSING ENGINE of Glafs, with a 
Brafs-Neck, Rammer and Valve fitted to it. 
A WEATHER CLOCK. Begun by Sir Chr. Wren, (c) (V> See iaa. 
now Prefident of the Royal Society. To which other f 0 fdyf° yd 
Motions have fince been added, by Alt. Robert Hoohje-w- 
Profefforof Geometry mGrefham-Colledge. Who purpofes 
to publifh a Defcription hereof. I lhall therefore only take 
notice, 
