132 MEETING OP THE BRITISH ASSOCIATION 



recent crocodiles. He shewed a singular gradation from the recent 

 saurians to sauroid fishes, by means of this arrangement of verte- 

 brae, which became an excellent guide in the discrimination of the 

 genus of Saurus ; and he concluded his communication with a quo- 

 tation from Agassiz, respecting the progressive development of ani- 

 mal life. 



A paper was read by Mr. Hopkins, containing theoretical views 

 respecting the geological phenomena of elevation. The principal 

 object of the author in this paper was to investigate the effects of 

 an elevating force acting simultaneously at every point of portions 

 of crusts of the globe, of considerable superficial extent ; and he 

 shewed that the theoretical inferences deduced from the hypothesis 

 are in striking accordance with the phenomena he had observed in 

 the limestone and coal districts of Derbyshire. He pointed out that 

 in that district the directions of dislocation were not such as could 

 result from the influence of the jointed structure of the rocks as the 

 determining cause of those directions. He also shewed how the 

 theory he had discussed will account for nearly all the phenomena 

 of mineral veins which can be attributed to mechanical causes, as 

 well as for the formation of systems of artificial lines, of faults, and 

 of other phenomena of elevation. 



Thursday. — Mr. Murchison having taken the chair, the Mar- 

 quis Spinetto read a paper entitled " A report of the attempts made 

 to ascertain the Latitude of the ancient City of Memphis." The 

 details of this communication are of importance to geographers, as 

 tending to elucidate a point on which Pocock, Shaw, Bruce, and 

 others, have differed. The question may now be considered to be 

 set at rest, it having been clearly ascertained that it was in the pre- 

 sent bed of the Nile, in latitude 29° 46' north, and longitude 31° 30' 

 east, from Greenwich. The chairman congratulated the section on 

 having heard these satisfactory details, and observed that the same 

 process which had buried the ancient city of Memphis in the bed of 

 the Nile — an accumulation of mud and drifted Lybian sands, in 

 consequence of the demolition of the dykes, which once turned aside 

 the water — had already sunk the beautiful fossil beds of Purton be- 

 neath the Severn. 



Mr. Murchison then quitted the chair and was succeeded by Dr. 

 Buckland, who stated that he had received engravings, prepared 

 under the direction of M. Agassiz, of some of the splendid fossils in 

 the Bristol Institution ; and he also placed upon the table a copy of 

 his work on Geology, forming one of the Bridgewater Treatises. 



The next paper was On the Change in the Chemical Character 

 of Minerals, induced by Galvanism. Mr. Fox mentioned the fact, 

 long known to miners, of metalliferous veins intersecting different 

 rocks containing ore in some of these rocks, and being nearly barren 

 or entirely so in others. This circumstance suggested the idea of 

 some definite cause ; and his experiments on the electrical magnetic 

 condition of metalliferous veins, and also on the electric conditions 

 of various ores to each other, seem to have supplied an answer, in- 



