558 R. T. CHAMBERLIN 
water from coming in contact with the lava in the conduit. What- 
ever may be the reason for the small amount of chlorine given off 
by the volcanoes of Hawaii, sea water does not reach the heated lavas 
in sufficient quantities to affect them appreciably. 
On account of the pressure exceeding the crushing strength of the 
rock, pores and crevices cannot exist at depths greater than 30,000 
feet according to the most generous estimate,’ and it is probable that 
continuous cracks cease much short of this. Beyond this extreme 
figure, meteoric waters cannot be regarded as of any quantitative 
importance, on account of the extreme slowness of diffusion through 
solid bodies not containing minute fractures. Liquid carbon dioxide, 
still existing under great pressure in sand grains of pre-Cambrian 
age, is a concrete example of this slowness. While, theoretically, 
water may extend downward to the limit of the zone of fracture, the 
testimony of deep mining appears to show that meteoric waters 
grow relatively scant, as a rule, below the uppermost 1,500 to 1,800 
feet of the earth’s crust.2 This shallowness of meteoric water 
increases the difficulties encountered by the hypothesis that the lava 
beds are supplied from this source, since they rise from far greater 
depths and only the upper portions of their conduits would be exposed 
to these waters. It is in this portion of the zone of fracture that 
Daubrée’s much-quoted experiment upon the Strasbourg sandstone? 
finds its application, if anywhere, since numerous capillary pores with 
plenty of water are requisites for the operation of this principle. ‘This 
famous experiment demonstrated that, owing to its force of capillarity, 
boiling water will pass through a disk of sandstone, 2 centimeters 
in thickness, against a slight steam-pressure on the other side. But 
it was only necessary for the steam-pressure to reach 685 millimeters, 
or nine-tenths of an atmosphere, in order to prevent any more water 
from passing through the sandstone. It is a long jump from this 
trivial capillary force, equal to less than one atmosphere of steam 
pressure, to the great pressures which would have to be overcome 
in the depths of the earth’s crust in order to reach the hot lavas, even 
t Hoskins, 16th Ann. Rept., U. S. Geol. Surv., p. 853. 
2 Kemp, Economic Geol., Vol. I (1907), p. 3; Finch, Proc. Col. Sci. Soc., Vol. VII 
(1904), PP. 193-252. 
3 Daubrée, Etudes synthétiques, Tome 1, pp. 236-46. 
