PHYSICS AND NATURAL HISTORY OF GENEVA. 267 
rations, and submitted some of the instruments cut from silex which are found 
in the quaternary formations of that, precinct. ‘These axes, as they are called, 
occur in the bed of gravel which also contains the bones of animal species now 
extinct. In the bed of white sand which overlies the stratum containing them 
he met with a geode composed of well-defined crystals of hyaline quartz. ‘The 
position of these crystals, as M. Favre maintains, shows that they were formed 
since man has inhabited the earth. This recent origin of the quartz would ex- 
plain how crystals of that substance come to be found on a projecting point of 
one of the axessexhibited to the society, since they could only have been formed 
after the translation of the gravel and the axes. 
From the same colleague we received an account of some geological obser- 
vations which he has recently made in Maurienne. On the right bank of the 
Are, between St. Jean and the pass of Encombres, he found that the forma- 
tions were folded or bent like the bottom of a boat, while the rock of the coal 
formation comprised between the former locality and the tunnel of the Alps 
presents, on the contrary, a sort of fan-like structure, and a vault in the eastern 
part of this vast group. From these observations he concludes that the forma- 
tion which contains the anthracites between St. Michel and Modane pertains 
to the true coal formation, that it is covered by the triassic rock, and that the 
liassic and nummulitic strata occupy, in relation to the other formations, the 
same position as in other countries. 
A statement was also given by M. Favre of the observations and experi- 
ments of M. Daubrée on metamorphism, whereby the latter has shown that, in 
explaining this class of phenomena, the action of water is to be taken largely 
into account. With these results of M. Daubrée our colleague collated the dis- 
covery of M. Sozby of the existence, in all granitic quartz, of myriads of small 
cavities, filled, some with gas, others with liquid. He further called to our 
notice a discussion which had arisen in the Geological Society of London. M. 
Murchison has observed, over a great extent of Scotland, gneiss resting upon 
quartz, even argillaceous schists and limestone resting upon granite. This im- 
mense group could not owe its origin to a local inversion of strata, like those 
observed here and there in the Alps. M. Nicol earnestly contested the exist- 
ence of this overlying gneiss. ‘This report gave occasion to M. de Saussure 
to remark that M. Logan has described this superposed gneiss as existing in 
Canada to such an extent as to exclude all idea of an inversion. 
At our last meeting, M. Favre recounted an excursion which he had made 
with M. de Morlot to the cone of erosion of the Tiniere, near Montreux, and 
explained the theories of that savant on what he calls the Roman deposit, four 
feet below the present surface; the deposit of the age of bronze, six feet be- 
low the former; and, ten feet lower still, the deposit of the age of stone; together 
with the reasonsyon which he founds those distinctions and names. 
The Society has been favored by Professor Pictet with numerous communi- 
cations relative to paleontology, of which the following are the most important. 
Hirst, a notice on the succession of cephalopod molluses, during the chalk period, 
in the region of the Swiss Alps and the Jura. He derives from a detailed study 
of the fossils contained in the cretaceous strata of Ste. Croix, and their compari- 
son with cotemporaneous repositories, an argument in favor of the idea pro- 
pounded by M. Barrande, that two successive faunas must necessarily have ex- 
isted together for some time, and he concludes by showing that paleontological 
faunas distinguished throughout by marked characters are not ordinarily sus- 
ceptible of any rigorous limitation. MM. Claparede and Favre took occasion 
to remark how much the conclusions of M. Pictet must in future complicate the 
task of the geologist who undertakes to determine the age of a formation. 
Led by his study of the neocomian fossils to determine a great number of 
fragments of unrolled cephalopods, M. Pictet has attentively considered their 
