264 ‘Translations and abstracts from the French. 
zine, was completely preserved. The copper retained its 
brightness, while the iron, tin or zinc were strongly oxidated. 
3. A simple plate of very thin mica placed between the 
copper and the iron of the preceding experiment, promptly 
destroyed the preserving effect of the iron: the copper was 
oxidated. r 
4, A platina wire was placed so as to unite the copper and 
the iron, the immediate contact of which had been broken 
by the mica: the copper was again perfectly preserved, and 
not an atom of oxide of copper appeared in the fluid. ‘This 
phenomenon of the preserving effect of iron, even when it is 
not in immediate contact with the copper, and when con- 
nected with it onl a conducting wire of another metal 
was perfectly demonstrated by the following experiment. 
5. A plate of copper was connected by a platina wire with 
a plate of iron, and the plates were placed separately in two 
vases filled with sea water, while the fluids themselves were 
connected by moistened cotton or by a syphon filled with 
the same fluid. ‘Fhe copper was completely preserved—the 
water retaining its perfect transparency—while the iron in 
piece of copper, which was oxidized within the first day- 
'The water therefore had lost none of its power and the phe- 
nomenon admits of no explanation on that ground. 
Neither had the copper lost the property of being oxidiza- 
ble by sea water, for the same piece, placed in another ves- 
of sea water was quickly attacked. It would scem then 
that the electric seme: action which iron and sea water 
exert upon copper, prolonged during a certain period, produ- 
ces between the elements of the coppee and those of the fluid 
