INDUSTRIAL PROGRESS DURING THE YEAR 1875. lxvil 



having the oxides of carbon, chiefly the dioxide, as their 

 characteristic gases, instead of hydrogen. 2. The propor- 

 tion of carbon dioxide given off is much greater at low than 

 at high temperatures, and is sufficient to mask the hydrogen 

 in the spectrum. 3. The amount of the gases contained, in a 

 larire meteorite, or a cluster of such bodies serving: as a com- 

 etary nucleus, is sufficient to form the train as ordinarily ob- 

 served. 4. The spectrum of the gases is closely identical 

 with that of several of the comets. 



Montigny has discovered, by means of an ingenious appa- 

 ratus which he calls a scintillometer, a connection between 

 the variations of color of scintillating stars and their spectra. 

 In every case those stars which scintillate or twinkle least 

 are those whose spectra show numerous well-pronounced 

 lines, sometimes united in zones. 



Capron has examined with a spectroscope especially con- 

 structed for the purpose the spectrum of the aurora, and has 

 compared it with that of hydrogen, oxygen, oxides of carbon, 

 coal gas, air, hydrogen phosphide, iron, and mercury under 

 various conditions. He differs from Angstrom in his conclu- 

 sions, first, as to the presence of moisture in the auroral re- 

 gions, and, second, as to the importance of the violet pole 

 spectrum in air. 



Huggins has sent to the Royal Society a note on the spec- 

 trum of Coggia's comet, which presented in the spectroscope 

 three distinct spectra : (l) a continuous spectrum coming 

 from the light of the nucleus; (2) a spectrum consisting of 

 bright bands ; and (3) a continuous spectrum accompanying 

 the gaseous spectrum on the coma, and representing almost 

 entirely the light of the tail. 



Lubarsch has published a paper on fluorescence, in which 

 lie concludes from his investigations (l) that for each fluo- 

 rescent substance there are only certain rays of light causing 

 fluorescence; (2) that the color of the fluorescent light de- 

 pends on the rays of incidence, and follows Stokes's law ; and 

 (3) that the most refrangible fluorescent rays produced by 

 sunlight correspond to that place in the spectrum where the 

 liquid shows its maximum of absorption, provided its fluo- 

 rescence proves a simple one when examined by prismatic 

 analysis of the linear spectrum. 



Mascart has made some very delicate experiments on the 



