78 Intelligence and Miscellaneous Articles. 



bers which agree with those in 2 and 3. From 1, 2, and 4 the 

 great influence of the structure on the thermo-electric deportment 

 is evident ; and this influence is seen still more strongly in 5 and 6. 

 While crystallized cobalt pyrites is strongly negative to copper, 

 amorphous is positive. The following phenomenon is still more 

 striking. The galena mentioned in 13 consisted of a group of crys- 

 tals ; hexahedra combined with octahedra. A group of pure octa- 

 hedra was found to be positive towards copper in some parts, and 

 negative in others*. 



The element 14 has, of all investigated, the greatest electromotive 

 force. Of those investigated by Marcus., at the highest applicable 

 temperatures, 18 go to a Daniell's. Yet the minerals investigated are 

 bad conductors, which is a hindrance to an extended application of 

 the elements adduced. But so much the more are the results avail- 

 able for the physics of the earth, on which account these investiga- 

 tions will be continued as soon as more copious material has been 

 obtained. — PoggendorfFs Annalen, April 1865. 



ON THE TERRESTRIAL RAYS OE THE SOLAR SPECTRUM. 

 NOTE BY M. JANSSEN. 



The memoir which I now submit to the judgment of the Aca- 

 demy contains an exposition and discussion of observations made 

 during a recent journey to the Alps, of which the following is a 

 summary. 



On the Faulhorn I observed a general diminution of all the groups 

 of telluric rays of the solar spectrum, a result arising from the alti- 

 tude of the place, and which shows the telluric origin of these lines. 

 On the contrary, I noticed that the lines of solar origin retained 

 their intensity and even gained in sharpness. The observation of 

 Mr. Glaisher, who after a recent ascent stated that he saw the 

 rays of the solar spectrum diminish with the ascent of the balloon, 

 appears to me to be in opposition to facts. 



* On this occasion it may be allowed to call to recollection the remark- 

 able but also never yet completely published observations, of which Mar- 

 bach, in the year 1857, has given a short notice in the Comptes Rendus, 

 vol. xcv. p. 707. According to these, crystals both of iron pyrites (FeS 2 ) and 

 of arsenical cobalt (CoS 2 -(-CoAs 2 ) fall into two classes, not as regards their 

 chemical composition or crystalline form, but as regards their thermo- 

 electric deportment. Denoting them by cc and /3, Marbach gives the 

 following series, counting from negative to positive : — Glance- cobalt and 

 bismuth a, ; argentine, platinum, lead, copper, brass, silver, cadmium, iron, 

 antimony, glance-cobalt (3. 



Becquerel has recently found that sulphuret of copper (Cu 2 S), formed 

 by melting together sulphur and copper, forms with copper, which is nega- 

 tive to it, a thermo-pile, of which ten elements, with a difference in tem- 

 perature of 300° to 400° C, have equal electromotive force to a Daniell's 

 element. Yet it must have a fibrous structure ; if in its preparation it is 

 heated too strongly, or several times remelted, so that it forms a homoge- 

 neous mass, it has almost entirely lost its power. — Comptes Rendus, vol. Ix. 

 p. 313. 



