After Gilbert has given in this Book an account of ancient and modern writings on the loadstone,[31] he indicates exactly what the latter is, where found, its different properties, and, having introduced us to his _terrella-microge_, or little earth[32]--a globular loadstone, showing that it has poles answering to the earth’s poles, he tells us all about iron ore, its natural and acquired poles, the medicinal virtues attributed by the ancients to iron as well as to the loadstone; and he ends this First Book with the announcement that loadstone and iron ore are the same, that iron is obtained from both, like other metals from their ores, and that all magnetic properties exist, though weaker, both in smelted iron and in iron ore; furthermore, that the terrestrial globe is magnetic and is a loadstone; and that just as in our hands the loadstone possesses all the primary powers (forces) of the earth, so the earth, by reason of the same potencies, lies ever in the same direction throughout the universe. BOOK II The justly famous Second Book contains Gilbert’s electrical work and, as is generally known, the second chapter thereof is the earliest ever published on electricity. We are here introduced to Gilbert’s _versorium_--a rotating needle electroscope[33]--and are given the results of his many experimental observations[34] and the opinions of others relative to magnetic coition or attraction. We find, throughout the whole of the second chapter, the first systematic study of amber, with an interesting list of electrics and the recognition of a group of anelectrics--non-electrics. After pointing out the different kinds of attractions admitted by Galen and other ancient writers, we are told that: “Only feeble power of attraction is possessed by some electrics (all which have their own distinct effluvia) in favouring dry atmosphere: observable in midwinter while the atmosphere is very cold, clear and thin, when the electric effluvia of the earth offer less impediment and electric bodies are harder--that these bodies then draw, as well, all metals, wood, leaves, stones, earths, even water and oil, in short, whatever things appeal to our senses or are solid. “All bodies are attracted by electrics, save those which are afire or flaming or extremely rarefied.