cil PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 
channel, the increased heat of which is transmitted to the bottom of 
the pipe. The water in the channel becomes boiling, and the steam, 
no longer condensing, acquires great power by compression, and 
finally drives out the water through the pipe. The same facts having 
been observed at the Strokkur, the same explanation is offered. 
M. Dumont, in a memoir on the value of the paleontological cha- 
racter in geology, endeavours to ascertain the aid geology may de- 
rive from organic remains: first, as regards the relative age of super- 
imposed beds in the same country ; secondly, in comparing the dates 
of rocks situated in countries remote from each other; and thirdly, 
in order to fix the limits of formations. He concludes, after entermg 
upon detail, that fossils are valuable in the same country in deter- 
mining the relative age of rocks formed at epochs very distant from 
each other, while they gradually lose this value as the formation of 
the beds approached each other m geological time. Under the second 
head he infers that analogous bemgs have existed in different locali- 
ties at different times, that the series of organisms belonging to differ- 
ent latitudes have commenced at distinct epochs by analogous spe- 
cies, and that the organized beings existing at the same time in the 
various geographical zones were as different formerly as they are now. 
With respect to the limits of formations, M. Dumont concludes that 
paleeontological divisions cannot exactly accord with the geological 
divisions founded on the revolutions of the globe. 
In some reflections on the nature and application of characters for 
determining rocks, M. Frapolli remarks that, zoological characters 
beimg only of comparative value, and mineralogical considerations 
constantly leading us wrong, it is to superposition of rocks, or their 
stratigraphical arrangement, that we must look for the sole true base 
of geological science, and that our principal attention should be di- 
rected to it when determining unknown formations. M. Frapolli 
passes in review the hypothesis of the original igneous fiuidity of the 
earth and its consequences, as the heat radiated into space and the 
crust became solid, adverting to times of repose and fracture, the 
accumulation of sedimentary deposits and their upheaval, and espe- 
cially referring to secular upheavals and their results. 
M. de Verneuil read a note on the parallelism of the paleeozoic 
rocks of North America and Europe, followed by a table of the fos- 
sil species common to the two continents, with the indications of the 
groups in which they are found, and a critical examination of each 
of the species. In this communication M. de Verneuil, describing 
the composition of the palzeozoic rocks of New York, of which he 
enumerates the twenty-eight groups into which they have been di- 
vided by the New York State geologists, pomts to the excellent suc- 
cession of beds observable in that part of North America. He also 
gives an account of the groups, thirty-eight in number, mto which 
the paleeozoic rocks of Ohio, Kentucky and Indiana have been di- 
vided, and then proceeds to examine into the parallelism of these 
North American deposits with the older fossiliferous rocks of Europe. 
He investigates this subject upon the principle, that if in two coun- 
tries a certain number of systems, characterized by the same fossils, 
