Scientific Intelligence. — Mineralogy. 373 



logous to what Greenland now is, and when an icy mantle extended 

 itself from higher plateaux into the fronds or friths on its sides. — 

 (Sir Roderick Murchison's Address to the Royal Geographical 

 Society, vol. xxiii., p. lxxxiii.) 



10. Professor Dove on Oceanic Currents. — The influence of oceanic 

 currents, says the Earl of Rosse, on the temperature of the regions in 

 which they prevail, was very inadequately appreciated before the pub- 

 lication of these researches. Of these currents, the most important, and 

 infinitely the most interesting to ourselves, is that so well-known as 

 the Gulf Stream. Its immense influence in moderating the winter 

 cold along the shores of western Europe, is shewn by the singularly 

 abnormal position of the winter isothermals in that region ; and not 

 only is this fact of great interest in itself, and of first-rate impor- 

 tance in meteorology, but it has also enabled the geologist to form a 

 far more accurate estimate than otherwise it would have been possible 

 to have done of the probable climatal influences of particular con- 

 figurations of land and sea, and thus to overcome, not by arbitrary 

 hypothesis, but by logical deduction, some of the greatest apparent 

 anomalies in speculative geology. The former existence of glaciers 

 in our own islands need no longer be regarded as a mystery, for it 

 is now demonstrable that they would be highly probable, if not ab- 

 solutely necessary, consequences of any configuration of land and sea, 

 which should divert the Gulf Stream from its present course ; and 

 the geologist has no difficulty in conceiving such a configuration, not 

 merely as a possible, but as one which probably did exist during the 

 glacial period. I mention this as an instance of the diffusive influ- 

 ence of a great step in one science on the progress of science either 

 more or less directly associated with it. A further and very important 

 conclusion has been deduced by Professor Dove, from the monthly 

 isothermals ; I mean the fact that the mean temperature of the sur- 

 face of the globe, as a whole, is higher when the sun is in the northern 

 than in the southern signs. The explanation is, that the northern 

 hemisphere has more land than sea at the surface, and the southern 

 much more sea than land, and that from the different action of the 

 sun's rays on the solid and fluid surfaces, it follows that the hot 

 summer of the northern hemisphere, added to the milder winter of 

 the southern, gives a mean of general temperature several degrees 

 of Fahrenheit higher than the cool summer of the southern, together 

 with the cold winter of the northern hemisphere. — {Proceedings of 

 the Royal Society, vol. vi. No. 99 ; Earl of Rosse' 's Address at the 

 Anniversary Meeting of the Royal Society, London. 



MINERALOGY. 

 11. On the supposed new metal Aridium. — Some years since 

 Uligren published a paper upon a substance found by him in a Nor- 

 wegian chromic iron ore, and which he considered as the oxide of a 

 new metal, closely resembling iron in its chemical properties and 

 relations. Bahr has carefully examined the mineral in question, 



