British Association for the Advancement of Science. 287 
contact of the platinum in the usual way did not produce any effect, 
whereas, when an acidulous solution of silver is used, platinum ex- 
ercised its usual influence. 
In the case of six metals, platinum checks the action of nitric 
acid, and three of them appear to be brought into a permanently 
peculiar state, opposed to chemical action. Platinum always sepa- 
rates any film of oxide as its initial function, but after its separation, 
it exercises a polarizing action, for example, it brings the other 
metal into a peculiar state, which enables it to resist chemical action. 
On the conclusion of this paper, the President drew the attention 
of the Section to the analogy between the facts detailed by Dr. An- 
drews, and the preservation of iron by brass, as instanced in the 
communication of Mr. Hartley. In both cases, according to the 
known laws of electro-chemical action, effects, the very opposite of 
what are observed, should present themselves. ‘The bismuth, cop- 
per, &c. should oxidize quickest when in contact with the platinum ; 
and if, as would seem demonstrated by Mr. Hartley, brass protects 
wrought and cast iron, the brass itself should be acted upon with in- 
creased rapidity. The solution of these anomalies, he conceived 
quite within the range of science in its present state, and he urged 
upon the members of the Section the necessity of studying the phe- 
nomena in question, as their explication would constitute a very 
valuable addition to the existing state of our electrical knowledge. 
Gravel, bowlders, &c.—Mr. Sedgwick had seen gravel on moun- 
tains two thousand feet high. Erratic blocks, he considered, could 
not be of fluviatile, but of marine origin, and organic remains of 
large animals were not likely to be abundant in gravel carried by 
currents of the sea, from the destruction caused by their violent ac- 
tion. Animal remains had been found in the clay gravel of the east 
of England; but this gravel he conceived as differing from that in 
other parts of the country.—Sir Philip Egerton said, that Mr. Strick- 
land’s flintless gravel, occurring to the N. W. of the Avon, could be 
only a partial formation, as he had. observed, that in Cheshire the 
gravel always contained flint. At Cocknell he had obtained two 
grinders of an elephant, and many marine shells, and many like 
shells in other places, all of existing species, and occurring often 
with pieces of rolled coal.—Mr. Phillips stated, that one of the 
questions proposed by the Association, was the determination of the 
phenomena of the English gravel formations, but to the present 
time sufficient evidence had not been collected. He alluded to Mr. 
