On Sir H. Davy's Safe- lamp for Mines. 19G 



\vhen fairly stated and rationally investigated, not one of 

 them militates in the slightest degree against the perfect safety 

 of the lamp. — And here it may very probably be urged, and 

 with perfect truth, that all this was known before, from Sir 

 Humphry Davy's own experiments, and consequently that mine 

 are quite superfluous. — I readily admit it. Sir Humphry, at the 

 first suggestion that danger was apprehended by the miners from 

 the coal-dust, immediatelv submitted the lamp to rigorous trials, 

 to prove how well or ill their fears were founded. He repeatedly 

 threw coal-dust, powdered rosin, and witch meal, through 

 lamps burning in more explosive mixtures than ever occur in 

 coal-mines ; and though he kept these substances floating in the 

 explosive atmosphere, and heaped them upon the top of the 

 lamp when it was red hot, yet he never could communicate ex- 

 plosions by means of them. Phosphorus and sulphur only pro- 

 duced that effect by being applied to the outside of the lamp, 

 and even thev required to be in large quantities and blown vpon 

 ly a mrreut (f fresh air. — Vide Philos. Magazine, vol. xlviii. 

 p. 54. The liberal and enlightened will not be disposed to 

 question the truth of this statement, from one whose candour 

 and accuracy are equally acknowledged ; and to such all further 

 evidence is work of supererogation, — to them 1 do not write: — 

 but we have seen, unhappily, that all are not of that class; and 

 though I do not hope to reclaim the perverse and malicious, I 

 notwithstanding am anxious, as far as my feeble efforts can assist, 

 to prevent others really desirous of the truth, from being misled 

 into the path of error and unfounded scepticism. Feelings of 

 attachment towards a man whom I glory in calling my friend, 

 cannot but create in me a warm interest for all that tends to 

 exalt the lustre of his well-acquiretl fame; — but beyond the feel- 

 ings of friendship, or the fame of my friend, 1 am anxious for 

 the prevalence of truth, ard that one of the greatest benefits 

 science ever conferred on humanity should shed the full influence 

 of its blessing, spite of the malicious insinuations of ignorance 

 and envy. — 1 return to the experiments. 



Erp. I. I sus])etulefl the lamp in my latithorn and threw in 

 tlie coal-gas from a bladder as before ; and when the gauze cy- 

 linder was filled with flame, a mixture of about three parts of 

 finely levigated coal-dust and one part of gunpowder-dust vvas 

 thrown into the lanthorn, which occasioned an abundance of 

 sparks within the gauze cylinder, but no explosion of the ex- 

 terior gas. 



Exp. 2. I fixed a small tray of very thin copper-])late, con- 

 taining the mixture of coal-dust and gunpowder, about three 

 inches above the wicj^ of the lamp within the gauze cylinder, 

 suspended the lamp in the lanthorn, and threw in the gas as 



Vol. 4H. No. 221. Sept, ISIG. N before. 



