224 Scientific Intelligence. 
position, and the higher or lower temperatures of fusion resulting 
therefrom, together with the higher or lower temperatures to 
which they have been Pia ene at the different volcanic foci, 
determine their difference of flow (under — on conditions) 
and of ee ig after ejection and cooling. 
St. Clair de ae d Fouqué have pees that the gaseous 
ejections, of wh pera its probably 99 per cent, are such as 
arise from water aeaittted toa preéxistent focus of high pehcieatci 
Whether it be sea or fresh water is not material, when we bear 
mind that the chemical constituents found in sea water and i 
a 8 
nom which are presented by voleanic vents, for to treat of 
diene 4 at all would be to more than double the size of this Giger 
prenatal lakes of lava, ete. 
For the first time, too, we discern a true physical cause for 
earthquake moveme ent, where voleanic energy does not show it- 
self. The crushing of the wo oe solid shell, rete thick or 
thin, go saltum and at evers hifting places, - however 
steadily the tangential pressures producing it may act.* Hence 
= hge earn) to the tension resulting from the earth’s contraction is 
cause of earthquakes presented by the writer in his Manual of Beale? (ase: 2), an! 
previously as resis as 1847, in — on the Results of the Earth’s oe 
published in volumes iii and iv of the second series of this Journal.—J. D. D 
