Proceedings of the British Association. 163 



Sir D. Brewster made several communications. 1. On Lumin- 

 ous Lines in certain flames corresponding to the defective lines 

 in the Sun's light. 2. On the structure of a part of the Solar 

 Spectrum hitherto unexamined. 3. On the luminous bands in 

 the Spectra of various flames. I. After noticing Fraunhofer's 

 beautiful discovery as to the phenomena of the line D in the 

 prismatic spectrum, Sir David said, he had received from the es- 

 tablishment of that eminent man, at Munich, a splendid prism, 

 made for the British Association, and one of the largest perhaps 

 ever made ; and upon examining by it the spectrum of deflagra- 

 ting nitre, he was surprised to find the red ray, discovered by Mr. 

 Fox Talbot, accompanied by several other rays, and that this 

 extreme red ray occupied the exact place of the line A in Fraun- 

 hofer's spectrum, and equally surprised to see a luminous line, 

 corresponding with the line B of Fraunhofer. In fact all the 

 black lines of Fraunhofer were depicted in the spectrum in brill- 

 iant red light. The lines A and B turned out in the spectrum 

 of deflagrating nitre to be both double lines ; and upon examin- 

 ing a solar spectrum under favorable circumstances, he found 

 bands corresponding to these double lines. He had looked with 

 great anxiety to see if there was any thing analogous in other 

 flames, and it would appear that this was a property which be- 

 longed to almost every other flame. II. He had, by means of 

 the prism from Munich, been enabled to extend the solar spec- 

 trum beyond the point where, according to Fraunhofer, it ter- 

 minated immediately at the side of the line A, and he (Sir Da- 

 vid) found one part to consist of about sixteen lines, placed so 

 near to each other, that it was difficult to recognize the separa- 

 tion ; but the lines as they approached to A were much nearer 

 to each other than as they receded from it ; consequently, that 

 portion of the spectrum appeared concave, resembling so much 

 the scooped-out lines of a moulding on wood, that it was scarcely 

 possible to suppose that the beholder was not looking at such a 

 moulding. He was led to observe an analogous structure near 

 the line B ; and upon carrying on this comparison of structure of 

 one part of the spectrum with that of another, it seemed to him, 

 that by and by, something important would result : for there was 

 a repetition of a group of lines, and similar lines, through different 

 parts of the spectrum, as if the same cause which produced them 

 in one part, produced them in another. III. He had endeavored 

 to procure all the minerals and artificial salts and other substances 



