286 On Sir Humphry Davy's Snfe- lamp, 



m shrubs (sec fig. b", aaa), but it is very difficult to make them 

 a))pear within. 



tit Mrs. Ibbctson is much slinckcd at a double mistalxC made by her rc- 

 speclint; the scale ol" the thermometer, which was Celsiis's, (p. 184, Sept.) 

 of which not beiiicr accustomed to the scale, and not liavini; her books with 

 licr, she was deceived \>y the person to whom she applied. It however only 

 makes the assertion respecting the heat the more impossible to be belieTed. 



%* In Mrs. Ibhctson's last communication, p. 181, line i5,for " higher 

 regions" read " lower regions;" and in p. 185,./ur " approaches" read " ap- 

 paratus." 



LVII. On Sir Humphry Davy's Safe-lamp, and on Flame, 

 By J. Murray, M.D. 



To Mr. Tilloch. 



SiRj — It has ahvays been my most anxious wish to combat 

 whatever doubts I may have found to exist on the perfect secu- 

 ritv held out to the miner by the continued use of Sir Humphry 

 Davy's safe-lamp. 1 have clieerfuUy descended into the abysses 

 of the mine to exhibit my unshaken confidence in, and entire 

 conviction of, its safety. 



That on its introduction prejudice did exist, cannot be denied; 

 but this, the offspring of ignorance, was soon dispelled by the 

 beam of truth. It is difficult to believe that any one nurtured 

 in the paths of science can for a moment honestly doubt of the 

 sufficiency of the security. Let them with me enter the mine, 

 that we may rejoice together. 



The extraordinary phaenomena presented by this discovery 

 were on their announcement rashly questioned, and I am glad 

 of it. — " yires acquirit eundo." The most sublime discoveries 

 that have adorned the annals of science have had their ordeal to 

 pass, and they have risen with livelier loveliness from the cruci- 

 ble of trial. 



In my experiments in the mine I have ventured to place 

 the lamp in th&jei of a blower: — this would seem to contradict 

 the experiments of Mr. Holmes. In the Dee Bank Colliery, 

 when the fire-dpmp was flaming in the cylinder, I projected 

 , against it a quantity of that highly inflammable powder called 

 lycopodium; but even this had no other effect than to increase 

 the intensity of light. Like an enraged and imprisoned tiger, 

 it simply gratified the admiring eye with the form it presented 

 and beauty of its appearance. With this shield I could en- 

 counter the fire-damp in its most terrific form : and when my 

 services in the cause of humanity are demanded, I think I shall 



not 



