The mean result of the best determinations shows that when a current of one ampere is passed for one second, a mass of silver is deposited equal to o ooi i 18 gramme.
The value of the constant / 7 ranges in different metals from about o ooI to 0.04; in soft iron and steel it is said to be generally not far from 0.002.
But the Benedictines, whose settlement in Hungary dates from the establishment of their monastery at Pannonhalma (c. 1 ooi), were the chief pioneers.
Acetylene tetrabromide, C 2 H 2 Br 4, which is very conveniently prepared by passing acetylene into cooled bromine, has a density of 3 ooi at 6° C. It is highly convenient, since it is colourless, odourless, very stable and easily mobile.