THE FLAME OF A CANDLE. 259 



tliat tlie bright rays can Le recognized on tlie bright part of the 

 solar spectrum only by the difference of their brilliancy. On the 

 other hand, we have not recognized the presence of the emission 

 spectrum of carbon among the numerous bright rays observed 

 in the spectrum of the solar atmosphere ; and this fact goes to 

 indicate the absence of carbon among the constituent elements 

 of the sun. But such an assertion can not be made until our ac- 

 quaintance with the subject becomes more complete and clear. 



Although it is hardly possible, in the actual state of our 

 knowledge, to establish the presence of carbon in the sun, it is 

 extremely easy to recognize it in the spectra of comets. In 1868, 

 when the comets of Winnecke and Brorsen appeared, Secchi in 

 Italy, Huggins in England, and "Wolf in France, studying the 

 sx)ectra of those stars in respect to their composition, discerned 

 that the three bright bands, yellow, green, and blue, of which 

 they were formed, could be regarded as analogous with the spec- 

 trum of carbon. It is possible, in fact, in a gas-light re-enforced 

 by oxygen, if the brightness of the flame is reduced and a spec- 

 troscope of feeble dispersion is used, to obtain a spectrum exactly 

 like that of a comet. After these observations, Mr. Christie and 

 myself recognized the violet band in the spectrum of the comet 

 h of 1881, and Dr. Young has found that the green band, or the 

 inost brilliant one in the spectrum of this comet, is formed of 

 rays like the corresponding green band of the spectrum of flame. 

 The identity of the two spectra is therefore demonstrated. 



The presence of carbon is also suspected, if not definitely rec- 

 ognized, in the spectra of certain stars, the orange or red color 

 of which indicates a temperature of relatively inferior elevation. 

 The spectra of these stars consist of several dark bands, super- 

 posed upon a continuous bright spectrum, which present a great 

 similarity of aspect and position with the luminous bands of the 

 spectrum of carbon in comets, illuminating gas, and the candle- 

 flame. We have then, here, the absorption spectrum of carbon. 

 The spectral analysis of the candle-flame thus permits us to dis- 

 cover by optical methods the presence of one of the most impor- 

 tant elements of our globe in luminous bodies, whether celestial 

 or terrestrial, whatever their distance, even though it be so great 

 that light occupies thousands of years in coming to us. — Trans- 

 lated for the Popular Science MontliJij from del et Terre. 



While generally accepting Mr. James Murray's views regarding the formation 

 of barrier reefs and atolls, Mr. J. L. Wheaton would regard as the principal agent 

 in forming the interior lagoons, not the solution and washing out of dead coral 

 by sea-water, but privation of the inner part of the reef of food, all nourishment 

 having been absorbed by the corals of the outer reef from the water before it 

 reaches the interior. 



