conductivity of the seven metals:— Silver 109·10 Copper 100·00 Gold 72·70 Lead 69·10 Platinum 18·20 Palladium 16·40 Iron 14·60 The practical result of these experiments was that it came to be recognised that, among the metals, copper might be employed to greater advantage as a lightning conductor than iron: a much lesser substance of it doing the same service of passing a given quantity of electricity from the clouds harmlessly into the earth. Sir Humphrey Davy was followed in his researches on the conductivity of the different metals by the electric force, by a number of other scientific men. His immediate successor in entering upon this line of observations was a French naturalist of eminence, Antoine C. Becquerel. Perhaps no man after Benjamin Franklin studied the phenomena of electricity with such thorough insight, free from all misleading theoretical delusions, as Becquerel. He was educated at the Polytechnic School of Paris, and in 1810, at the age of twenty-two, entered the army as an officer of engineers, but quitted it five years afterwards with the rank of colonel, to devote himself entirely to scientific pursuits. Geology and mineralogy first engaged his attention, but he soon quitted these studies to devote himself, heart and soul, to the observation of the phenomena of electricity, which fascinated him as much as they had done Benjamin Franklin. The result was the discovery of a great many facts previously unknown, making Becquerel, amongst others, one of the founders of the science of electro-chemistry. The result of his researches concerning the conducting power of the electric force by different metals may be stated as follows: Copper 100·00 Gold 93·60 Silver 73·50 Zinc 28·55 Platinum 16·40 Iron 15·80 Tin 15·50 Lead 8·30 Mercury 3·45