Dec, 1904.] 



KNOWLEDGE & SCIENTIFIC NEWS. 



285 



The VitoLl Eacrth. 



By Gkenvii.i.e A. J. Cole. 



The .-' wness of the processes of mountain-building 

 and denudation, the coldness of common rock, and the 

 manifold signs of activity, on the other hand, in the 

 organic kingdoms, have conspired to make us regard 

 our planet as a dead mass, the destiny of which is now 

 concentrated in that of the human race. 



There is no doubt that man and his movements 

 have the supremest interest for ourselves. Ethno- 

 graphers have discussed the influence of environment, 

 and have seen the geographic cradle, as it were, re- 

 flected in the characters of a tribe. But, again and 

 again, the migrations of peoples, with customs and 

 manners ready formed, have shown us that man may 

 finally impress himself on his new surroundings, in- 

 stead of being forced into their mould. Our pre\alcnt 

 classical education, moreover, ignoring natural pheno- 

 mena on the one hand, and the long struggks of 

 prehistoric man upon the other, tends further to fix 

 our attention on the dominant position that we have 

 attained. 



But is the earth on which we move so very lifeless 

 after all? If we construct a diagram to show how 

 much of this ball, 8,000 miles across, is accessible to 

 our direct enquiries, we are at once brought face to 

 face with the enormous possibilities of the interior. 

 We are familiar with the circulation of water, for 

 example, between the atmosphere and the uppermost 

 and disintegrated layers of our rocks; but we may well 

 ask if all the water, and all the gases, were success- 

 fully extruded at the period of the consolidation of the 

 crust. This period, again, is still in progress; the 

 crust is far from stable, and grows by additions from 

 below. Substances, till now occluded, may be given 

 out, when passage is afforded to them during the 

 movements of the upper layers; others may become 

 incorporated in the crust, and may ultimately be 

 brought within our reach, in their Liter modifications, 

 upon the surface. 



Prof. Suess, of \'ienna, has recently pressed home 

 upon us the distinction between permeating superficial 

 fluids, as defined by Posepny, and those that are in 

 reality nascent and come to us from below. We still 

 meet in newspapers, and in many scientific text-books, 

 the theory that the waters of volcanoes originate from 

 inroads of the sea; and the influence exercised bv this 

 view is emphasised by the clearness with which Prof. 

 Suess has found it even now necessary to stand out 

 against it. " The steam of volcanoes," he says,* 

 " cannot arise from infiltration from the surface, and 

 such infiltration is clearly out of the question in the 

 ca.se of the carbon dioxide. Whence, then, do these 

 substances arise? They proceed from the deeper inner 

 regions of the globe, and are the outward signs of that 

 loss of gases, which began with the first consolidation, 

 and which is not completely over, though localised at 

 certain points and lines. In this way the oceans and 

 the whole superficial (-.'adose) hydrosphere became 

 separated from the body of the globe. \'olcanoes are 

 not fed by infiltrations from the sea, but the seas in- 

 crease in volume as the result of each eruption." 



• " Ueber heisse Quellen," Address to the Society of German 

 Naturalists and Doctors at Karlsbad, 1902 (Prometheus. XIV , 

 1903, p. 226). 



Suess points out that this proposition is not new; 

 yet it needs repeated allirmalion. I'rom some points 

 of view, in fact, the interior of the earth, with its 

 concentrated metals under high temperatures and 

 pressures, is still young and potent, a planet still 

 capable of giying off light-rays of its own, were its 

 stony envelope removed. The incandescent glow of 

 the material ejected from volcanoes brings us, as 

 Tschcrmak has indicated, near to the cosmic forces 

 that are common to the systems of the stars. The 

 liberation of gases and " emanations " in the past is 

 no real measure of what remains occluded in our own 

 (lav. Combinations, moreover, may be possible at the 

 existing high temperatures in the interior, which lower 

 temperature and relief from pressure may in time con- 

 vert into other and even st.irtling forms. 



The object of the present paper is to ask for a 

 suspension of judgment in regard to several questions 

 which geological instructors are apt to pass over as 

 well proven. A wise review of this matter appears in 

 the last edition of Sir A. Geikie's " Text-book of Geo- 

 logy " (1903, pp. 351-8), where many useful refer- 

 ences to published papers will be found. We gain 

 new interest in the water that permeates volcanic rocks 

 from the amazing eruptions of Martinique and .Saint 

 \incent in IQ02. The stories of poisonous gases and 

 fiery exhalations soon gave way before scientific 

 examination; the burning and scorching effects proved 

 to be due to hot volc.inic dust, sent forth in such 

 (|uantitics as to practically exclude the common air. 

 No n.ime or ordinary combustion was possible until 

 the dust-cloud relaxed its first closeness and intensity. 

 Moreover, its very texture and continuity seem to have 

 been due to the evolution of water-\apour from each of 

 the myriad particles that were ejected simultaneously 

 from the vent. But it is difficult in such catastrophic 

 examples to realise what is actually going on, and what 

 gases are being liberated so abruptly from the parent 

 earth. The study of the vapour-jets and hot springs 

 that remairi in volcanic areas for centuries after activity 

 in the ordinary sense h;is passed away, has gi\en us 

 an impressive picture of the immense streams of matter 

 passing from the inner rocks into the hydrosphere. 

 The prevalence of carbon dioxide is especially striking. 

 N'ot only at the famous fJrotto del Cane near .\aples, 

 but at the far more accessible Grotte du Chicn at 

 Royat in the Department of the Puy-de-D6me, we 

 may become immersed in a bath of this dense gas as 

 it oozes from the pores of solidified volcanic ground. 

 The opening of a bottle of natural mineral water, 

 though the " sparkle " in different species occurs in 

 \ery different degrees, brings us into touch in a more 

 homely way with the unexhausted vitality of the earth. 

 Probably no one attributes the carbon of the gaseous 

 compound thus brought to the surface to the decay of 

 ancient vegetation within the crust, ^'et the case of 

 petroleum is probably similar; and here the material is 

 generally referred to as of an organic origin. A com- 

 bustible material, however strange its mode of oc- 

 currence and emanation, seems to suggest from the out- 

 set fossil forests and old swamps, and it is almost im- 

 possible to persuade " practical men " that carbon 

 exists in the earth apart from coal-seams. The very 

 fact that petroleum is in some cases successfully dis- 

 tillefl from Carboniferous shales is, moreover, 

 commonly held to prove its organic origin in all areas. 

 C'arbon and carl)on-<:ompounds, liowe\er, must have 

 existed on our globe long before living things arose 

 upon the surface, and it is no mere speculation to 

 suppose that much of the material remained unavail- 



