C 898 ) 
I. An Experiment made before the Pre fide vt and 
Fellows of the Royal Society, in rvhich a fur- 
pricing change of Celonr from a pale Tranfpa- 
rent or Clear Liquor, to a very Bine Cemleous 
one was exhibited, and that in aninfkant, by 
the admifpon of Air only : Apply d to illujlrate 
fome changes of Colour^ ard other EjfeSfs on 
the Blood of Refpiring Animals. By Fn 
Slare, M. D. Felloxp of R. S. and Cenfor of 
the Colledge of Fhyftcians. 
IN order to the making of this Experiment, the Ope- 
rator fhould furnilh himfelf with a quantity of Fil- 
ings of Copper frefh made, and place them in a Glafs 
Vial^ whole bottom is broad and even, and thea pour 
on a Urinous Spirit, either of Sal Amoniac, or of Urine 
itfelf, not made with Quick-Lime: The Glafs fhould 
not be fill'd up much above one half-way, and thenmuft 
prefently be fo exaftly llopt that no Air be capable of 
intruding; for if you err in a Circumftance the Experi- 
ment will not fucceed. The Foundation of this Experi- 
ment is juftly due to the Immortal Mr. Boyle, but our 
Aims are very differing in the Application, as well as in 
the manner of preparing and exhibiting the Experiment. 
He was fearching after fome hidden proprieties of the 
Air* and particularly apply'd it to the broken or leflen'd 
Spring of the Air, which this fhammenon afforded his 
Speculation. But I have endeavour'd to bring it home 
to my own Profeflion, to juftifie a Notion of fome Im- 
portance, tho 5 much difputed, concerning-an alteration 
made by the Air upon Humane Blood, both as to Co- 
