[ *+ 3 
XV. Experiments on the Production of Dephlogijlic cited Air from, 
JVater with various Subjianccs. In a Letter from Sir Benjamin 
Thompfon, Knt. F, R. S to Sir Jofeph Banks, Bart. P . R. S. 
i 
Read Feb. 15, 178-7. 
DEAR SIR, Munich, Sept. 1, 1786. 
■^"ARIOUS opinions having been entertained with refpedt to 
the origin of the dephlogifticated air, produced by expo- 
fing healthy vegetables in water to the adtion of th-e fun’s rays, 
according to the method of Dr. Ingen-housz ; and not being 
myfelf thoroughly fatisfied with any of the theories propofed, 
I made the following experiments, with a view to throwing 
fome new light upon that fubjedt. 
Having found that raw filk polfelfes a power of attradling 
and feparating air from water in great abundance, when expofed 
in it to the action of light, it occurred to me to examine the 
properties of this air, and to coniider more attentively the cir- 
cumftances attending its production, thinking that this might 
polfibly lead to fome further difeoveries, relative to the pro- 
duction of the air yielded by water under other circumftances : 
and though my fuccefs in thefe inquiries has not been equal to 
my willies, yet, as in -the courfe of my refearches I have dis- 
covered fome facts which I take to be new, and as I have con- 
firmed others, already known, by a variety of new experi- 
ments. 
