Remarks on the Planets Jupiter and Saturn. 341 



Olivine is much more frequently imbedded in basalt in 

 nodules than in separate crystals. These masses consist of 

 crystalline granular fragments, sometimes mixed with augite 

 and bronzite. As in basaltic tuffs, similar nodules of olivine 

 are found, which, on account of their less coherent granular 

 structure, may be easily broken down, there is the greater 

 reason to regard them as subsequent productions, because 

 no small particles or angular fragments are found near the 

 large nodules. 



At Charkow, Swoszowice, and other parts of Poland, amor- 

 phous sulphur occurs in nodules in marl ; and where the marl 

 has been converted into compact limestone, it presents vesi- 

 cular cavities, containing crystallised sulphur and calcite. 



In the case of all these nodular formations, it may be 

 assumed that there has been a segregation of the particles of 

 the minerals, for it would be difficult to suppose that they 

 were accidentally deposited in the manner they now occur ; 

 and moreover, many such nodules contain small nuclei of 

 the substance in which they are imbedded. 



(To be continued.) 



Some remarks on the probable present condition of the Pla- 

 nets Jupiter and Saturn; in reference to Temperature, 8fc. 

 By James Nasmyth, Esq.* 



The remarkable appearances which characterise the aspect 

 of the planets Jupiter and Saturn, as revealed by the aid of 

 very powerful and excellent telescopes, have induced some 

 reflections on the subject of their probable present condition 

 as to temperature. With a view to excite more special and 

 careful observation of the phenomenon in question, and pro- 

 mote discussion on this interesting subject, I have been 

 tempted to hazard the following remarks, which may per- 

 haps prove acceptable to some of the members of the Royal 

 Astronomical Society. 



In a former communication, in reference to the structure 



* Read at the Meeting of the Royal Astronomical Society. 



