Proceedings of the British Association. 373 
Dr. Thomson read a very valuable paper on mixtures of sulphuric 
acid and water, in which he shewed that the theory of Irvine re- 
specting specific heat cannot be true. 
r. Jones detailed the results of an elaborate analysis of wheat, 
and mentioned that he had formed a new and peculiar volatile fluid 
by the action of sulphuric acid on wheat. 
Section C.—Gro.ocy anp Groarapny. 
A paper was read by the Marquis Spineto on the geographical 
position of Memphis, in Egypt. The state of that city during the 
time of its long prosperity was first considered; then the causes of 
its destruction; and lastly, the opinions of different travellers re- 
garding its position. Its particular site had been described by an- 
cient historians as on an island in the Nile, evidently formed of the 
mud of that river; and that it had been protected from inundations 
by various inaiaian works erected by its kings. When its splen- | 
dor decayed, these works went out of repair, and hastened the ruin 
of the city, which strewed with its fragments the place on which it 
had stood. Finally, it was submerged under drifted sand, and its 
true position became a problem to modern travellers. Of late, how- 
ever, the site has been determined by the French, who, in one of 
their exploring expeditions, had examined the stratification of the 
place supposed to be Memphis, and they ascertained the spot by the 
succession of drifted sand, ruins, and mud. Its latitude they fixed 
at 29° 20’ N. and longitude at 31° 30’ E. from Greenwich.—Mr. 
Murchison spoke of the great value of geographical papers to the 
geologist, and of the one just read, as an excellent example of this 
kind.—Dr. Buckland took this opportunity of mentioning the estab- 
lishment of M. Van der Maelen, at Brussels. That gentleman had 
devoted, in the most praiseworthy manner, his time and fortune to 
the advancement of science, by making large geographical and geo- 
logical collections, for the purpose of diffusion over the world, by 
means of exchange with societies or individuals. Dr. Buckland ad- 
vocated such a mode of obtaining maps and specimens to the differ- 
ent provincial societies of the United Kingdom. 
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 
