1865.] Carter on a Plurality of Worlds. 229 



has shown that olivines, augites, anorthites, and other minerals analo- 

 gous to, though not strictly paralleled by, those of the earth, abound 

 beyond its limits ; while by a microscopic examination of the sections 

 of these Mr. Sorby has further shown that they have excellent glass 

 and gas cavities, like those present in lavas, proving that they once 

 contained vapour, and were in a state of igneous fusion. A very 

 intimate resemblance has thus been proved to exist between different 

 bodies in the solar system ; while by methods of research, available 

 for the examination of the physical constitution of bodies beyond its 

 limits, this resemblance has been found to extend in some respects to 

 them also. For the spectroscope reveals the very suggestive fact that 

 many of the fixed stars have at least a considerable proportion of 

 similar chemical elements to those which abound in the Sun and Earth, 

 and that the ones which are most extensively diffused, and of whose 

 evidence the clearest indications are afforded, are such as are known 

 to be most closely connected with the constitution of living organisms, 

 — just those indeed, which, when influenced by heat, light, and che- 

 mical force (all of which are undoubtedly radiated from these stars), 

 afford some of the most important conditions for the maintenance of 

 life.* True it is that no undoubted organic remains have yet been 

 discovered in any meteorite, or other body outside of the earth. Hydro- 

 carbons were, however, present in the stones of Kaba Bokkereld, &c, 

 and it is perhaps fairly open to question how far these may not 

 indicate the operation of organic agency, t But a similarity in 

 elementary constitution among the different members of our system, 

 necessarily implies other conditions, which serves to bring still 

 closer the likeness to one another. For so soon as a number of 

 chemical elements are in a position to exercise their natural affi- 

 nities, local forces of great intensity are developed, which inevit- 

 ably give rise to irregularities of outline. The same is true of 

 the simpler minerals which these elements by their union form, 

 many of them assuming such different volumes under similar circum- 

 stances of temperature and pressure, as to be competent to the pro- 

 duction of extensive fractures, elevations, and contortions in any mass 

 of which they form a considerable proportion. Thus, while granites, 

 syenites, and basalts diminish in density, though in very different 

 degrees upon the application of heat, zircons, yellow obsidian, and 

 others, augment. The variety of surface thus physically inevitable 

 from the possession by the planets of a similar elementary constitu- 

 tion, explains and gives additional force to the interpretation of 

 appearances visible through the telescope. If in addition to this 

 superficial inequality, water can be shown to be present, there will be 

 on other planets the elements of that ceaseless cycle of geological 

 change which is so marked on our own, namely, attrition, disintegra- 

 tion, lamination, and stratification, causes which combine for the pro- 

 duction of fertile soils. That this is present in abundance will be 

 evident when we inquire more particularly into the physical constitu- 



* 'Phil. Trans.' for 1864. "Huggins and Miller on Spectrum-Analysis of 

 Fixed Stars." 



t ' Proc. Boy. Inst.' and 'Trans. Brit. Assoc' "A. S. Hcrschel, B.A., on 

 Meteorites." 



