Geological Society. 413 
change of temperature. It could not be ascribed with reason 
to the presence of the radium. 
The light from the radium could be seen through a slab of 
iron an inch thick ; yet this manifestation of energy passed 
through the aluminium without any apparent effect upon the 
mechanism of the electric current. Should we reason, there- 
fore, from this negative experiment, that the theory of the 
immaterial electron is supported, or that a theory of dissocia- 
tive effect on gases between each molecule of the metallic 
conductor produced by a current is also negatived ; for the 
radium emanations, like the X-rays, can produce this «isso- 
ciative effect in the passage of electricity through gases ? 
Mr. McKay, graduate student working in this laboratory, 
has endeavoured to detect the effect of the X-rays in changing 
the apparent resistance of thin films of metals. The effect, if 
it exists, is extremely small. He, however, is still continuing 
his work upon this subject. 
Jefferson Physical Laboratory, 
Harvard University. 
XLI. Proceedings of Learned Societies. 
GEOLOGICAL SOCIETY. 
[Continued from p. 292. | 
April 13th, 1904.—J. E. Marr, Sc.D., F.R.S., President, 
in the Chair. 
_ following communications were read :— 
1. ‘The Discovery of Human Remains under the Stalagmite- 
Floor of Gough’s Cavern, near Cheddar. By Henry Nathaniel 
Davies, Esq., F.G.8. 
2, ‘ History of Voleanic Action in the Phlegrean Fields.’ By 
Prof. Giuseppe De Lorenzo, of the Royal University of Naples. 
In an introductory section the author sketches the general 
geological structure of the district around Naples, and shows the 
disposition of the chief lines of fracture by which the Triassic, 
Cretaceous, and older Tertiary formations were traversed, previous 
to the commencement of volcanic activity in this part of Italy. He 
recognizes three chief periods in the volcanic history of the district. 
I. The eruptions of the first series took place under the sea during 
the Pleistocene Period. Their surviving products can be grouped 
in two distinct divisions, each recording a different eruptive phase. 
The older of these (a) is represented by the piperno and grey 
pipernoid tuffs of the Campania, which extend under the broad 
plain into the valleys of the Apeninnes. These deposits consist of 
erey trachytic tuff, with scattered black scorie, and with a varying 
proportion of non-voleanic sediment washed down from the hills. 
The vents whence they were ejected are now no longer to be traced 
as they have been obliterated or covered up by later accumulations. 
The piperno, well developed at the foot of the Hill of the Camaldoli, 
Phil. Mag. 8. 6. Vol. 8. No. 45. Sept. 1904. 2F 
