Safety-lamp Controveisy. 67 



could not have been supported with air, except bv an aperture 

 Jifty times too large to have been safe, and the wick is too near 

 the source of air to have produced safety by the production of 

 azote and carbonic acid. 



When he first showed his lamp of December 5, he did not pre- 

 tend to have discovered any principle of security, nor was any 

 stated for him ; nor in September 1816, when he first published 

 his experiment of October 21, 1815. 



Mr. R. W. Brandling, in September 1816, however, in speak- 

 ing of his lamp of November 24, states fov Mr. G. Stevenson, that 

 he had embraced the idea tivo montlu bejore, " that hydrogen 

 gas admitted into a lamp in small detached portions might be 

 consumed bv combustion." 



Allowing this to be his principle, if an incorrect idea can be 

 called a principle, it becomes easy to explain his experiments 

 with the tube and the slider. The slider is an apparatus fitted 

 to detach : — the substitute of a person ignorant of chemistry for 

 the ingenious water valve of Dr. Clanny. 



To go back two months, would give the conception of this idea 

 on the 24th of September, when he must have heard that Sir 

 H. Davy was engaged in the inquiry respecting a safe light. 



From November, all that can be traced in his views, is a rude 

 attempt to identify his own crude notions and unscientific prac- 

 tical efforts with the results and principles of Sir H. Davy. 



In 1817, he has made a lamp which is a coarse imitation of 

 one of Sir H. Davy's earlier lamps ; but provided with his safety- 

 screw, his safety-trinmier, and safe apertures and canals below, 

 and a chimney-top of the same structure as wire-gauze above ; 

 yet even this apparatus, such is the want of chemical information 

 of the constructor, is highly dangerous — it is furnished with a 

 thick glass cylinder*, which breaks soon after the lamp is intro- 

 duced into an explosive atmosphere. 



It would be wasting time to show by minute details how little 

 Mr. G. Stevenson's evidence is to be confided in. 



In December 181.5, when his original ideas, if he had any, and 

 researches, if he had made any, must have been fresh in his nund, 

 he could give vo account of them; and in 1816, the first idea that 

 "he is said to have eml)raced, was that of burning detached i)or- 

 tions of hydrogen; but in 1817 every thing is perfectly clear to 

 him, and he states, that experiments which he had been making 

 for four years, led him to the discovery of the principle of the 

 non-transmibsion of flame through small apertures ! ! 



• The Messrs. Brandling, it is well known, do not use thh lamp, but Sir 

 H. Davys. 



E 2 That 



