410 Intelligence and Miscellaneous Articles. 



the question is asked whether the molecules of a metalloid do not 

 in structure lie between those of elements on the one hand and of 

 compounds on the other. 



These considerations are applied to solar and stellar spectra. 

 The general appearance of the solar spectrum shows that in all 

 probability there are no compounds in the sun. 



Secchi's maps of a large number of stellar spectra are referred 

 to as now indicating beyond all doubt the existence of compound 

 vapours in the atmosphere of some stars ; and it is suggested that 

 the phenomena of variable stars may be due to a delicate state 

 of equilibrium in the temperature of a star, which now produces 

 the great absorption of the compound and now that of the ele- 

 mental molecules. 



II. Mechanical Mixtures. 



The second part of the paper deals with the mechanical mix- 

 tures. Maps of the spectra of alloys of the following percentages 

 are given : — 



Sn and Cd percentages of Cd 10-0, 5-0, 1-0, 0-15. 

 Pb and Zn „ „ Zn 10-0, 5-0, 1*0, 0-1. 



Pb and Mg „ „ Mg 10-0, 1-0, 04, 0-01. 



It is pointed out that the lines disappear from the spectrum 

 as the percentage becomes less, the shortest lines disappearing first 

 —and that although we have here the foreshadowing of a quan- 

 titative spectrum-analysis, the method is so rough as to be inap- 

 plicable. 



It is then stated that further researches on a method which pro- 

 mises much greater accuracy are in progress. 



The bearing of these results on our knowledge of the reversing 

 -layer of the sun's atmosphere is then discussed. 



LIII. Intelligence and Miscellaneous Articles, 



ON THE CONDENSATION OF GASES AND LIQUIDS BY WOOD-CHAR- 

 COAL. THERMIC PHENOMENA PRODUCED ON THE CONTACT 

 OF LIQUIDS AND CHARCOAL. LIQUEFACTION OF THE CON- 

 DENSED GASES. BY M. MELSENS. 



ABSORPTION of chlorine by wood-charcoal may go on until it 

 represents a weight of chlorine equal to that of the charcoal ; 

 consequently the condensing force of the latter may serve to realize 

 the liquefaction of the non-permanent gases. 



Charcoal put into a tube similar to Faraday's A-shaped tube is 

 saturated with chlorine. The two extremities of this siphon tube 

 being then sealed at the lamp, if the long branch of the tube be 

 heated in a water-bath of boiling water, and the short branch be 

 dipped into a freezing-mixture, a considerable quantity of chlorine 

 leaves the charcoal and resumes the gaseous state ; and under the 



