54 



XV. 



ON THE INTERNAL HEAT OF THE EARTH, AND 

 SOME REMARKS UPON VOLCANOES. 



Abstract of Papert 



READ BY 



CAPTAIN McDAKIN, 

 13th May and 9th December, 1889. 



After reviewing the several theories respecting the internal heat of 

 the earth, it was suggested that this must, in part at least, be due to the 

 oxidation of organic matter, as shown by the large amount of carbonic acid 

 gas contained in spring water, as well as the large volumes of nitrogen 

 given oflE by the same, the air absorbed and carried down by rain water, 

 causing a slow combustion with organic matter washed out of the surface 

 soil. 



The King's "Well at Bath, which gives off in contained gases, 96 per 

 cent, of nitrogen, was mentioned in illustration, also the Bristol Hot Wells, 

 92 per cent , and Taafe's Well, Cardiff, 96 per cent. Now water absorbs 

 one measure of oxygen to two of nitrogen. " With these effects in view," 

 the lecturer continued, " I took some garden mould and a one per 

 cent, solution of permanganate of potash, allowing both to remain 

 in the same room for twenty-four hours, so that they might be of 

 the same temperature. I watered the mould with the solution. On 

 placing a thermometer in the earth so watered it rose two degrees in a 

 few minutes, showing the oxidation of organic matter had produced 

 heat." The question was then asked : — " May we not have, both in the 

 sun and the earth, a circulation of elementary matter in the solid or 

 surface portion of the crust, where under immense pressure, associations, 

 and dissociations take place, renewing the internal heat by chemical 

 action and the foi'ce of gravity?" Eor as in the animal and vegetable 

 we should not have the development of heat without vitality ; so in the 

 earth we should not have the same amount of heat as now exists 

 without gravity — the vital force of the earth, plants and animals, and 

 our laboratory experiments, all alike being subject to the same universal 

 law. The circulation of water may possibly be the vehicle of action with 

 our globe, but until we know of what particular component parts the 

 atmosphere of the sun consists, we cannot of course speak positively for 

 that luminary. 



Drawing attention to the evidence of volcanic action in the south- 

 east of England by the anticlinal of the "Weald, and the London and 

 Hampshire basins, with the cross flexures giving the initial direction to 

 the rivers draining the Wealden area — the author described some of the 



