IV. An Account of an Experiment, confirming one lately 
made, touching the Production of Light, by the Ef- 
fluvia of one Glafs falling on another in Motion, 
IBy Mr. Fr. Hauksbee, F. K. S. 
H Aving obferv’d that the Effluvia of Glafs were ca- 
pable of Exhibiting a Vhanometion falling on an 
Exhaufted Glafs in Motion, as if rub’d by a vjfibLe Solid 
Body, (as I lately fhow'd before this Honourable Society -0 
I thought a farther Confirmation of the fame, would not 
be unacceptable. In order thereunto, I devis'd the fol- 
lowing Experiment, 
I took a large Receiver in form of Fig. 2. a- a. a. a. 
Within the Body of which, I fixt another in manner and 
likenefs of b. b. k b. their Axis lying parallel to the Ho- 
rizon, and were fixt one within another at c. c. The 
outward furface of the inward Glafs was at leaft an Inch 
diftant from the inward furface of the outward one $ 
and were turn’d by two large Wheels, whofe Bands rela- 
ted to the final! Wheels d. d. d. d. fix’d on their Axis. 
The inward Glafs was firft Exhaufted of its Air $ then 
being fixt, as before deferib’d, I order’d that Wheel only 
to be mov'd, which gave Motion to the great Glafs 5 
thinking that when the Effluvia of that Glafs, by the Ap- 
plication of my Hand upon it, fhould reach the other, 
notwithftanding it was at reft, it would neverthelefs be 
afFefted by it and give a Light} which accordingly fell 
out as I expe&ed, fpreading its felf in flying Branches all 
over. Then caufing the other Wheel to be turn’d, the 
14 Y Light 
