Association of American Geologists and Naturalists. 147 
The President then requested Mr. George B. Emerson to take 
the chair, while he favored the meeting with some remarks “on 
hydrated minerals and antediluvian temperatures.” 
Prof. Rogers suggested whether the steam which so usually accom- 
panies volcanic emissions, may not have furnished the water of the 
hydrous minerals found in the serpentine, referred to by Dr. Beck. 
We may easily conceive that this steam, by mingling with the lava 
matter in some localities and not in others, might cause the difference 
between the igneous injections involving hydrous minerals and those 
destitute of them. Organic remains afford evidence of the existence 
of water upon our globe at very remote dates, as early as the eruption 
of many of the ancient basalts and serpentines. A source of the steam 
existed, therefore, in periods of very ancient volcanic action. 
Upon the subject of the ancient climate of the globe, Prof. R. avow- 
ed his dissent from the doctrine maintained by Prof. Beck, that the 
temperature of the ancient globe was uniform throughout the vast pe- ” 
riod of the secondary and tertiary races. He contended that we ought 
not to look for proofs of a very obvious refrigeration during any but a 
greatly prolonged period of geological time, since we must presume 
that the earth had already approximated to a statical condition of tem- 
perature at the time it became the abode of the earlier organic tribes. 
At the same time he appealed to the supposed habits of the ancient 
races, in support of the doctrine of a gentle and progressive cooling 
of the earth’s surface. The hypothesis of Poisson, which explains the 
changes in the earth’s general climate, by assuming the solar system 
to have passed successively into portions of space having different tem- 
peratures, being alluded to by Prof. Beck as offering a probable cause 
of the refrigeration in the past-tertiary period: Prof. R. stated that so 
sudden and transient a reduction of temperature must be considered as 
incompatible with the conditions of that theory. <A translation of our 
system into a cooler region of stars we cannot suppose to arise but in 
avery gradual manner, nor would the globe part generally with its 
heat when so near its statical condition, but with an almost impercepti- 
ble slowness. He referred to the influence of the Gulf Stream on 
climate and its obvious dependence upon the physical geography of 
America, to show that local geological revolutions in the northern lati- 
tudes, causing changes in the distribution of land and water, would be 
sufficient to produce a temporary distribution further southward than 
usual of the arctic mollusea. 
Mr. Gebhard also gave his views on the subject briefly. 
On motion of Mr. Emerson, the Association accepted the invi- 
tation of the Mohawk and Hudson, and Troy and Schenectady 
