SCIENTIFIC STTMMAKY. 
129 
the one belonging to the metal or conductor of which the electrodes are 
made ; and the other, to the gas through which the spark passes.” The 
object of his present investigation was to make a new examination and 
j accurate drawings of the solar spectrum ; to determine the wave-lengths 
of many of its lines, and also of the lines in the spectra of different 
metals. He has confirmed the statement of Kirchoff — that the atmo- 
sphere of the sun contains iron, magnesium, nickel, and chromium ; the 
lines due to iron “ are the most characteristic in the whole spectrum.” 
He adds, as a result of this last research, that calcium, aluminium, and 
manganese exist in the sun ; and also, in all probability, strontium and 
barium ; and concludes by some remarks on “ Fluorescence.” 
Mr. J. Attfield has examined, by the aid of prismatic analysis, various 
| flames containing carbon, and has found that ignited oxy-carbons, hydro- 
carbons, sulpho-carbons, and nitro-carbons emit certain rays of light in 
common ; and concludes that these rays emanate from ignited carbon 
I vapour. When observed by the unassisted eye, the prevailing colour of 
ignited carbon is light blue. By special manipulation, he has obtained 
the carbon spectrum with carbonic oxide, olefiant gas, bi-sulphide of 
carbon, and cyanogen. 
M. Jaunsen, in a note communicated to the French Academy of Sciences, 
affirms that he has recently been able to determine the presence in the 
solar spectrum of permanent rays which ought undoubtedly to be attributed 
to the action of the terrestrial atmosphere, and has constructed a spectro- 
scope by which he has been enabled to examine these rays or bands, 
moment by moment, from sunrise to sunset, and has found them to vary 
in intensity with the height or thickness of the atmosphere through which 
the sun’s light has to pass. 
Some time ago, Gladstone examined the nature of light which had 
passed through dilute solutions of nitrate of didymium, and discovered 
two dark lines in it by spectrum analysis ; and Professor Rood, of America, 
has lately repeated the experiments with a strong solution of considerable 
thickness of the same substance. He has found that when sunlight or 
lamplight is transmitted through a thickness of twelve inches of this 
strong solution, and analyzed by Kirchoff’s spectroscope, the spectrum is 
seen crossed by twelve distinct lines, some of which are very broad and 
others very fine. D, or the sodium line, is just cut off by one of these, 
and from this results the singular phenomenon that a sodium flame is 
invisible through a foot thickness of this liquid, although the liquid is 
nearly colourless and scarcely at all alters the tint of ordinary white 
objects viewed through it. 
In our last number, we stated that a French commission had examined 
and commended M. Serrin’s newly-invented regulator for electric lights ; 
since then, M. Serrin has exhibited his electric lamp at the Polytechnic 
Institution, London, and all agree in stating that the light emitted was 
perfectly steady and uniform in intensity — a result which has never 
heretofore been perfectly obtained with an electric lamp, and which was 
in the highest degree desirable. The following are some particulars of the 
structure and action of the lamp from a published description of it by 
M. Serrin ; and those who are acquainted with the mechanism of such 
VOL. II. — NO. V. K 
