440 Miscellaneous Intelligence. 



principles, such as the vapor of naphtha and and light carburetted hydro- 

 gen, or marsh gas, never before detected. The last eruption has likewise 

 caused an elevation of the coast to the height of 3 feet 1 inches above the 

 level of the sea, which has not been observed on any preceding occasion. 

 In speculating upon the causes which have produced these changes in 

 the nature of the operations of Vesuvius, the author first considers the 

 theory which recognizes a second class of volcanoes distinct from those 

 ordinarily known as such, and designated by the name of mud volcanoes. 

 As these are characterized by the emissions of carburetted hydrogen and 

 naphtha, as well as of semi-fluid mud, it might be suggested by those 

 who regard them as partakers of the nature of volcanoes, that Vesuvius 

 was now passing into the condition of a mud volcano from its emit- 

 ting these same products. But the author finds reason for denying that 

 the so-called mud volcanoes, of which Macalube in Sicily and taman in 

 the sea of Azof are types, have anything in common with genuine volca- 

 noes, such as Vesuvius, and he therefore contends that the above products 

 are generated simply owing to the action of volcanic heat upon contigu- 

 ous beds of Apennine limestone containing bituminous matters imbedded. 

 Hence would arise the enormous evolution of carbonic acid observed, and 

 the carburetted hydrogens as well as naphtha vapor which are found to 

 accompany it, and which may be regarded as the secondary and incidental 

 products of volcanic action, whilst the muriatic and sulphurous acids are 

 primary and effectual ones. The auther concluded by recommending to 

 the explorers of volcanic phenomena the accurate examination of the 

 gases evolved, as the best clue to the explanation of the true nature and 

 cause of volcanic action. The latest remarks of Deville and others on 

 volcanic emanations present nothing irreconcilable with the chemical 

 theory of volcanoes which the author has so long espoused ; but all he 

 asks of geologists is, diligently to record the facts, chemical as well m 

 physical, which volcanoes present, instead of contenting themselves witn 

 simply referring the eruptions to certain great cosmical changes which 

 they imagine to be taking place. ^. .. 



D. Zoology.— President, Prof. Huxley.— 0/i the Zoological Signifi- 

 cance of the Brain and Limb characters of Man, with Remarks on the 

 Cast of ike Brain of the Gorilla ; by Prof. Owen.— Prof. Owen exhibited 

 two casts, one of the human brain, which had been hardened in spirits, 

 and had therefore n(tt preserved its exact form, but to all intents and pur- 

 poses it would serve as an illustration of the human brain. The other 

 cast was taken from the interior of the cranium of the gorilla. From an 

 examination of these, the difference between the brain of man and that 

 of monkeys was at once perceptible. In the brain of man, the posterior 

 lobes of the cerebrum overlapped, to a considerable extent, the small brain, 

 did not project beyond the lobes of the cerebellum. The posterior lobes 

 in the one were prominent and well marked ; in the other, deficient. 

 These peculiarities had been referred to by Todd and Bowman. From » 

 very prolonged investigation into the characters of animals, he f*^"^ Pf ' 

 suaded that the characters of the brain were the most steadfast; and tie 

 was thus induced, after many years of study, to propose his class9ihc-»«'>P 

 of the mammalia, based upon' the differences in the development ot tbeir 

 braiQ structure. He had placed i ■ - ^f 



