38 Hydro-orygen Blowpipe. 
My experiments were also repeated by Mr. Rubens Peale, dur- 
ing many successive years, at the Philadelphia Museum, for the 
amusement of visitors. 
About the year 1813-14, it was ascertained, at the laboratory 
of Dr. Parrish, that a bladder being supplied with a mixture of 
hydrogen and oxygen, in due proportion, and punctured by a pin, 
while subjected to compression, on igniting the resulting jet, the 
gas within the bladder did not explode. Of course a burning jet 
of flame thus created, was found competent to produce, while it 
lasted, the same effect as when otherwise generated by the same 
gaseous mixture. 
this might be made to burn without communicating ignition to 
the portion remaining in the receiver. fot. 
By means of an apparatus contrived agreeably to this idea, Dr. 
Clark of Cambridge, England, repeated the experiments, made 
many years before by Silliman and myself, without any other 
reference to ours, than such as was of a nature to do injustice. 
An exposition of the invalidity of Dr. Clark’s pretensions to or- 
ginality was made in Silliman’s Journal for 1820, vol. it, and in 
ation in light-houses, and in consequence, has been subsequently 
used as a substitute for the solar rays, in an instrument known 
as the hydro-oxygen microscope, which is a modification of that 
which has been called the solar microscope. ‘The name of 
Drummond light has consequently been given to a mode of illu- 
ation, which I originally produced as above stated. 
The instrument which was used by Professor Silliman and by 
Rubens Peale, was that above described as having two perfora- 
tions meeting in one. In this form it was, I believe, employed 
by Dr. Hope, of Edinburgh, and Dr. Thompson of Glasgows 
who both treated it as my contrivance, anteriorly to the publica 
tion of Dr. Clark’s memoir. 
The other form, consisting of two concentric pipes, Was P” “ 
ified by a Mr. Maun , with the view of producing 4 9 
light for the microscope above alluded to. When I saw 
