406 Scientific Intelligence. 



certain colore are wanting which are present in the spectrum of another 

 body at the same temperature, is perfectly transparent for rays of these 

 colors, and that it exerts upon rays of any color present in its spectrum 

 an absorption which is powerful in its proportion to the brightness of this 

 color in its own spectrum. It also follows that when the source of light 

 which produces a continuous spectrum by which the spectrum of an ignited 

 gas is inverted, is an ignited body, its temperature must be higher than 

 thai of the ignited gas. 



The application of these principles to the determination of the chemical 

 constitution of the sun's atmosphere is well known. The author calcu- 

 > of 60 iron lines with 60 dark 



O.OOO.OOO 



, magnesium, and sodium in the sun's atmospher 



to be clearly proved. Barium, copper and ; 

 small quantity. Gold, si! 



'tin, lead, 

 B detected. 



Kirchhoff considers that the most probable assumption which we can 

 make as to the physical constitution of the sun is that the body consists 

 of an intensely ignited solid or fluid core surrounded by an atmosphere 

 of somewhat lower temperature, a theory which is perfectly consistent 

 with the nebular theory of Laplace. He elucidates and defends this the- 

 ory at length, maintaining that it is consistent with astronomical observa- 

 tions. For a full statement of the author's views on this subject hovvever 

 we must refer to the original memoir as the argument does not well ad- 



3. Some observations of the Solar Spectrum.— Weiss has availed him- 

 eelf of favorable opportunities presented by a voyage to the Ionian I^Ies to 

 examine the thickening of the dark lines in the solar spectrum produced 

 by atmospheric absorption. The thickening of the lines in the ^edjo^ 

 yellow portions of the spectn ' ' '' " 



! violet end of the spectrum in each instance, precisely as m 



the case of hyponitric acid and chlofophyll. The 

 was a Soleil's spectroscope and the observations were made at sunrise au" 

 sunset, the clearness of tlie atmosphere being extremely favorable.— /^W- 

 ^««. cxvii, 191. , ^"%e 



[N'ote.-~^YQ may here remark that the spectroscope promises to gi 

 important information with respect to several luminous phenomena 

 great interest. We mention as illustrations the aurora borealis, the zw 

 acal light, the colors of sunset clouds, and the light of comets. -^ ^ , 

 parison of the light of the aurora borealis, with tbe spectra P'"oa"ceti "> 

 electric discharges in Geissler's tubes filled with rarefied air, oxygen, ^"^^ 

 nitrogen would be of great interest as confirming the electric origi 

 this phenomenon. If the zodiacal light be due to a. ring of nebuio 

 matter around the sun or around the""earth it should exhibit lines corr 

 ponding to the vapors which it contains. A careful study of the co ^rj 

 of clouds at sunrise and sunset may explain the appearance of particu 



