ON THE ELECTRIC SPARtf. l^JJ 



J'erliaps the hypothesis of a number of small eddies, or 

 rolling cylinders of water, may account for it, as ihe ridges 

 are at right angles to the course of the undulation. In this 

 supposition, however, there appears too much of gratuitous 

 demand. — Have the goodness to propose the matter to the 

 consideration of your con-espondents, if you should think 

 a§ I do, that no fact can be too trifling for philosophical dis- 

 cussion. I am, SIR, 



Your obliged reader, 



R. B. 



XII. 



Questions on some Appearances of the Electric Spark : hy 

 Correspondent, 

 SIR, 



X Wish to be informed if it was ever remarked, that, when Question rc- 



an electrical spark is taken from the conductor of a ma- specimg van- 



.... ous appear- 



chine, the line of white light is interrupted, and the spark auces of the 

 becomes red. Sometimes it assumes the form of two cones, electric spaxk. 

 one preceding from the conductor, and the other from the 

 body which is applied to it : at other times the interruption 

 is next the conductor ; and again it will be perceived near- 

 est the body receiving the spark.' When the spark is taken 

 at the least distance possible, the light is sometimes red, 

 sometimes white ; and when the spark is some inches in 

 length, the interruption is perceived in two or three places 

 of the line of white light. Any explanation of these phe- 

 nomena will much oblige, SIR, 



Your humble servant, 



TYRO. 



XIII. 

 Extract of a Letter from Mr, BioT to Mr. Berthollet*, 

 Tarragona, 20tk December, 1S06, 



•3l Have had an opportunity of conversing with that excel- 

 lent observer, Mr. de Marty, on several subjects of experi- 



* Annales de Chimie, Vol.' LXI, p. 271, March, 1807. 



ments 



