320 Scientific Intelligence. 
from the voleanoes arises from the melting of solid rock, existing 
at a very high temperature, at points where there is a diminution 
of pressure, or else from comparatively small vesicles of rock in a 
molten condition.— Proc. Roy. Soc., June, 1881. 
6. Hepansion of Cast Iron while solidifying.—M. J. B. Han- 
nay and Roperr ANDERSON have a paper on this subject in the 
Proceedings of the Royal Society of Edinburgh for December, 
1879 (p. 359). By trials in different ways, the authors reach the 
conclusion that “liquid cast iron expands at least 5°62 per cent of 
its volume on freezing.” 
Il. Gronrogy AND Natura. History. 
1. Origin of the Iron Ores of the Marquette District, Lake 
Superior ; by M. E. Wapswortn. (Proc. Boston Soc. Nat. Hist., 
xx, 470, March, 1880.)—After a few prefatory sentences, this 
misdirected logic, “Can any geologist ever have been so ignorant 
of the mutual association of eruptive and sedimentary rocks as to 
have soberly advanced the above idea?” After discussing in this 
style “all the evidence which we are aware has been used to 
prove the sedimentary origin of the jaspilite and ore,” Mr. Wads- 
worth uses a still more personal method, the notice of which 1s 
unnecessary. : : 
Mr. Wadsworth, in his argument for an eruptive origin, which 
