176 Mr. Longmire on the Flame of a Candle, [March, 



animal so tenacious of life as the leech, should, shortly after 

 being swallowed, be found alive in the intestines of the stickle- 

 back, does not, therefore, appear wonderful, and that the stickle- 

 back should have died when " a few minutes " out of the water, 

 and in the hands of a child, is still less so. The wonder would 

 have been, had it continued to exist in an element so foreign to 

 its nature, independent altogether of the danger of leech- birth in 

 the hands of such assistants. 



Article V. 

 On the Flame of a Candle. By Mr. John B. Longmire. 

 (To the Editors of the Annals of Philosophy.) 



GENTLEMEN, 



A LIGHTED candle, beinga veiy interesting specimen of com- 

 bustion, I have added a trifle to our knowledge of it, in the 

 following observations, which I have the pleasure to send for 

 insertion in the Annals of Philosophy. 



By truncating the flame of a candle, as was first ingeniously 

 done by Mr. G. Oswald Syra, a cross section of the cone of flame 

 is obtained ; and it appears a dark disk, surrounded by a lumi- 

 nous ring. But in this case, the inflammable material, which 

 should form the upper part of the flame, is forced through the 

 meshes of fine gauze, and being, in the truncation of a common 

 candle, the vapour of oil and dissipated wick, partly decomposed, 

 and cooled down by contact with cold iron into an oily smoke, 

 it obstructs the view into the interior of the undisturbed flame. 



On commencing some experiments on the flame of a candle, 

 I had not any wire gauze with me, so I made a temporary instru- 

 ment with some coarse wire, which, happening to have only two 

 oblong meshes, divided the flame at the top of the cone ; and, 

 on sinking it a little, the flame and some smoke continued to 

 pass upwards on the outside of the exterior barrs. In conse- 

 quence, I saw down the interior to the bottom of the blue flame. 

 The wick is black, except where in contact with flame. A space 

 is observable all round the wick, between it and the blue flame. 

 The whole of the interior, except the wick, is alight transparent 

 medium. 



The vapour of melted tallow issues mostly from the low part 

 of the black wick, where the heat is least in it, and the melted 

 tallow, or warm oil, greatly prevails there. 



The oil from this part of the wick has a blue flame. When 

 tallow is touched with red-hot iron, it burns with a white flame ; 

 but so soon as the iron has cooled below red heat, blue flame 

 commences. We thence see the reason why blue flame is 



