580 



MOON, RECENT OBSERVATIONS AND STUDY OF THE. 



or sea could live even with the abundant pres- 

 ence of water. Excepting some of the earliest 

 forms of infusorial life, whose shells are com- 

 posed of oxide of silicon (silica), all the shells 

 of the mollusks, both of land and water, are 

 carbonate of lime, i. e., oxide of carbon (car- 

 bonic acid) and oxide of calcium (quicklime). 

 So we might go on through a volume, but 

 enough has been said to show that all the pan- 

 orama of life is due solely to the oxidation of 

 the elements of matter. The limitations of an 

 article like this preclude the possibility of mar- 

 shaling, in their order of succession and strength 

 of numbers, the facts that demonstrate the pro- 

 cess through which the elements of matter are 

 oxidized in the progress of creative energy 

 and thereby prepared for the production and 

 succession of life upon celestial globes ; but an 

 outline will indicate the nature of the sources 

 whence they have been drawn. 



The first illustration represents a few of the 

 planetary orbits, from the least to the most 

 extreme degree of eccentricity, shown in un- 

 broken black lines. The better-known com- 

 e'ary orbits are also exhibited, from their least 

 to their greatest degrees of eccentricity, in 

 dotted or broken lines. The major axes of 

 all the orbits are of the same length for the 

 purpose of conveying more directly to the eye 

 their various degrees of eccentricity, which 

 would be confusing if each orbit were drawn 

 upon its relative scale of magnitude. The 

 most eccentric of the planetary orbits (that of 

 Nysa) has very nearly the same degree of ec- 

 centricity as that of Fay's comet, which is the 

 least eccentric of cometic orbits; and from 

 the circular orbit of the planet Neptune 

 throughout the entire group, the element of 

 eccentricity has the character of progressive 

 modification without anything like interrup- 

 tion, distinction, or break where planetary ec- 

 centricity merges into that of the comet. The 

 distinction made by astronomers in this re- 

 spect, therefore, seems arbitrary. The bodies 

 that inhabit the middle ground of orbital ec- 

 centricity always present a hazy appearance 

 when in that part of their orbits which is 

 nearest to the sun (perihelion), it matters not 

 whether they have been named planet, plan- 

 etoid, or comet; and as this is the only por- 

 tion of these very eccentric orbits in which the 

 bodies inhabiting them are discernible, it is 

 evident that there is no distinguishing physical 

 characteristic or aspect to warrant us in assert- 

 ing which is a comet and which a planet. 

 From this middle ground, in the direction of 

 decreasing eccentricty, the bodies gradually as- 

 sume the aspect of planets ; and beyond it, in 

 the direction of increasing orbital eccentricity, 

 they as gradually assume the unmistakable 

 characteristics of comets. The physical as- 

 pects of the whole group of planets and com- 

 ets observe a condition of modification corre- 

 sponding to the degree of eccentricity of the 

 orbits they separately inhabit, and no link in 

 the chain is absent or broken. 



The eccentricity of the orbits of both planets 

 and comets is gradually but perpetually decreas- 

 ing, and the physical aspects of all comets are 

 being steadily modified toward that of planets. 

 For example, when Encke's comet first became 

 known to astronomers, it developed at perihe- 

 lion a tail 30 in length ; now it appears, at 

 perihelion as a hazy globe, while its orbit is 

 as gradually decreasing in eccentricity ; if these 

 two processes are continued, at their present 

 rate, it will require but a few thousand years 

 to make it a planet of the solar system. Hal- 

 ley's comet, though having a very eccentric 

 orbit, as may be seen by the illustration, has 

 lost much of its cometic characteristics since 

 first it became known, being also modified to- 

 ward the planetary condition, both in its phys- 

 ical aspect and in eccentricity of orbit. In 

 truth, comets are but worlds in process of crea- 

 tion, and their establishment as planets of the 

 solar system is but a question of time. Ob- 

 serve in the illustration, for example, that all 

 comets with a less degree of orbital eccentricity 

 than that shown by Halley's, revolve about the 

 sun in the same direction that the planets do, 

 and beyond this degree the orbital characteris- 

 tic has practically ceased to exist, and assumes 

 that of journeys to and from the sun in all 

 modifications of the more extreme and there- 

 fore most eccentric conic sections. These also 

 are the comets that display the most startling 

 cometic phenomena at perihelion, in which 

 portion of their orbits comets are alone dis- 

 cernible not because many of them would 

 not be telescopically visible in other portions 

 of their orbits, but because the intensity of the 

 solar heat, when they are nearest to that great 

 crucible, expands their matter so enormously 

 as to make them frequently perceptible to the 

 unaided eye. This, probably, is when and 

 where the elements of matter undergo oxida- 

 tion, simply by being raised to high tempera- 

 tures and literally burned. The comets whose 

 orbital eccentricity has approximated that of 

 planets no longer display marked cometic 

 characteristics, because their decreased eccen- 

 tricity of orbit precludes the possibility of their 

 approaching as near the sun at perihelion as 

 formerly; hence they exhibit only a hazy en- 

 velope, precisely the same as our own world 

 did at that period of its geological existence, 

 when it is supposed to have been a molten 

 globe enveloped in its own vapors. Comets 

 beyond this degree of orbital eccentricity ex- 

 hibit at perihelion all modifications of the 

 opposite extremes, not only having their less 

 refractory forms of matter vaporized to invisi- 

 bility, and thereby exhibiting their solid globes, 

 but those globes themselves are, in many in- 

 stances, dissipated to invisibility, and the entire 

 comet occasionally remains in that condition 

 for weeks or months. But the matter invaria- 

 bly reassembles when the comet, on its out- 

 ward journey, after passing perihelion, recedes 

 far enough from the source of heat to permit 

 the now cooling forms of matter to begin to 



