Mr Talbot's Experiments on Coloured Flames. 77 



an effect like a wind round the face of' the traveller?'' He also 

 says, that he himself, as well as other credible persons, " had 

 often heard the rushing qf them just as if a strong wind had been 

 blowing, (although there was a perfect calm at the time) or 

 like the whizzing heard in the decomposition qf certain bodies 

 during a chemical process."" It also seemed to him that he 

 noticed " a smell qf smoke or burnt salt.'''' " I must yet add, 1 ' 

 says Gisler, " that people who had travelled in Norway, in- 

 formed me they had sometimes been overtaken on the top of 

 mountains by a thin fog, very similar to the Northern Lights, 

 and which set the air in motion ; they called it sildebleket, 

 (Haring's lightning) and said that it was attended by a pier- 

 cing cold, and impeded respiration ." Dr Gisler also asserts, 

 that he often heard " qfa whitish gray cold fog qf a greenish 

 tinge, which, though it did not prevent the mountains from 

 being seen, yet somewhat obscured the sky, rising from the 

 earth, and changing itself at last into an Aurora; at least, such 

 a fog was frequently the forerunner of this phenomenon." 



To these observations, Professor Hansteen adds, that Cap- 

 tain Abrahamson, in the Transactions of the Scandinavian Li- 

 terary Society, has given an account qf several observations qf 

 noises that were heard along with the Northern Lights ; and the 

 learned Professor concludes with the observation, that he him- 

 self knows several persons that have heard the same sounds. 



Art. XV. — Some Experiments on Coloured Flames. By H. 

 F. Talbot, Esq. Communicated from the Author. 



Great progress has recently been made in investigating the 

 properties of light, and yet many of them are still unexamin- 

 ed, or imperfectly explained. Among these are the colours 

 of flames which not only appear very various to common ob- 

 servation, but are shown, by the assistance of a prism, to be 

 entirely different in nature one from another ; some being 

 homogeneous, or only containing one kind of light ; others 

 consisting of an infinite variety of all possible shades of co- 

 Jour. 



1. It was discovered by Dr Brewster, that the flame of al- 



