222 



On some Recent Spedroscopie Researches. [April, 



by passing a powerful induction-spark between tbe points of plati- 

 num wires, sealed in glass tubes, through olive oil. A similar 

 spectrum is given by the spark in cyanogen. The other spectrum 

 of unbroken shaded light was obtained by the spark in olefiant gas. 

 It is with this modification of the spectrum of carbon that the 

 spectrum of the comet appeared to agree precisely, not only in the 

 position of the bands, but also in the special characters of the Hght 

 of each band. The circumstance that in the comet's spectrum 

 the bands become shorter as well as fainter towards the more 



refrangible limit of each band was due to the arrangement of hght 

 in the comet itself. The appc<arance of the comet in the telescope 

 is represented in Fig. 1 ; the slit was placed across the head of 

 the comet. The greater brightness of the central spot permitted 



