1870.] Notices of Scientific Works. 369 



the axis of the planet to its orbit. But our information concerning 

 Mars does not stop here, for astronomers are sufficiently convinced 

 of the existence on its surface, of continents, islands, oceans, seas, 

 straits, and inlets, to have given them such designations as W. 

 Herschel Continent ; Kepler, Lockyer, &c, Lands ; Phillips Island ; 

 Dawes Ocean ; De la Eue Sea ; J. Herschel Strait ; Nasmyth Inlet, 

 &c, as may be seen from Mr. Proctor's interesting chart in the 

 work under review ; and if these surmises be correct — if the fair 

 face of Mars is divided into land and water, and if its skies are 

 varied with clouds and sunshine, it is only a reasonable inference 

 that in every other respect its physical aspect resembles that of our 

 own earth ; its continents being diversified by hill and dale, plain 

 and valley ; its valleys adorned with lakes, and serving as the beds 

 of rivers; whilst waterfalls will likely adorn its hill sides, and 

 glaciers its mountain recesses. And if so, cui bono 1 Are there no 

 trees and shrubs to draw their nourishment from its streams and 

 watercourses? no insects nor other flying things to flutter in its 

 sunshine? no living, moving beings to wander over its vast con- 

 tinents ? And if some of these should still be absent, has all this 

 beauty been produced in vain for ever ? We leave the common 

 sense of our readers to dictate the answer, for they are as well 

 able to form an opinion on the matter as the author of the work 

 before us. 



From the slight inclination of its axis, Jupiter has no seasons 

 in the ordinary acceptation of the term, but probably the planet 

 possesses a cloud-laden vapour with its consequences. It is pos- 

 sible that Jupiter may be in a condition somewhat similar to that 

 in which our earth was when its seas swarmed with ancient forms of 

 life. Mr. Proctor does not say so, but judging from the necessity 

 of a supporting medium for its animal races (if it possess any), in 

 consequence of their additional weight as compared with those on 

 the earth's surface, as will be explained presently, and from other 

 circumstances, such a view is worth consideration. Saturn, too, has 

 probably an atmosphere laden with vapours ; and here our know- 

 ledge, which can hardly be called positive, of the phenomena favouring 

 the existence of life in other parts of our Solar system, terminates. 



There are, on the other hand, certain well-established pheno- 

 mena which render life impossible upon certain other spheres. The 

 photosphere of the Sun consists probably of glowing vapours, amongst 

 which those of many well-known elements, such as iron, calcium, 

 magnesium, as well as hydrogen gas, have been distinctly traced by 

 spectrum analysis ; and so, too, similar elements in the same form, 

 sodium, magnesium, iron, hydrogen, have been clearly ascertained 

 to exist in some of the fixed stars.* In such an atmosphere, it is 



* See Huggins " On Recent Spectroscopic Researches," ' Quarterly Journal 

 of Science,' April, 1869. 



