On the Gas Blowpipe. 333 



moistening quick lime, may easily conceive that tremendotis effects 

 might ensue from reaction between water and calcium, or any of 

 the same family of substances. In this case hydrogen would be 

 produced, but there would be no oxygen. — Of the existence, how- 

 ever, of subterraneous fires in voicanic regions there can be no 

 doubt, whatever may be the theory of their origin. The obvious 

 proximity of springs, rivers, and even of the sea itself, with the 

 well known force of steam, renders it easy to point out the proxi- 

 mate cause of earthquakes, or of volcanic explosions and erup- 

 tions, without calling in the gas blowpipe to our assistance. 



That Dr. Clark could not without great injustice bring forward 

 his mode of o})erating, otherwise than as another method of doing 

 what I had previously accomplished, nor his experiments, unless 

 as an extension of those made by Professor Silliman and myself, 

 will be perfectly evident, if it be considered that we all employed 

 a flame of the gaseous elements of water, in the one case, mixed 

 during the eflflux, in the other, before; that the most important 

 results in both instances will, on comparison, be found nearly the 

 same. 



The mode of confining and propelling the gases through the 

 pipe or pipes to the place of eflflux, is irrelevant to the question. 

 There are many methods by which this object may be accom- 

 plished. The principle of the apparatus used by Dr. C. will be 

 found the same as that of the air vault employed in England to 

 regulate the blast of large bellows at foundries and forges. Mr. 

 Brook was the first to apply it to the regulation of a blowpipe, 

 and published his account of it on April 8, 1816. 



I will proceed to quote and exhibit simultaneouslv, the obser- 

 vations and experiments of Dr. Clark, and of Professor Silliman 

 and myself. As Tilloch's Philosophical Magazine is universally 

 accessible, I shall refer to it for the memoirs of Silliman and my- 

 self: to vol. 14 for mine, to vol. 50 for his*. For Dr. Clark's 

 experiments, commenced in 1816, 1 shall quote his book on the 

 gas blowpipe, published 1819. 



Expeiiments on Lime. 

 Hare, page 304. " Lime and magnesia arc extremely diflicult 

 to fuse, not only because they are the nmst refractory substances 

 in nature, but from the difficulty of preventing them from being 

 blown on one side by the flame : nevertheless, m sonic instances, 

 by exposure on carbon to the gaseoua flame, small portions of 

 these earths were converted into black vitreous masses. Possibly 

 the black colour of these products of fusion, nuiy have I)ccn caused 

 by iron contained in the coal ; for in the high temperature of the 



• These experiments v/crc pcrlonricd in Dccciu'ier 1811, and published 

 ill IJrucc's Journal in lttl2. 



gaseous 



