THE BEGINNING OF MODERN ELECTRICITY.

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erate, orderly effort to study electricity as a separate and distinct entity in the economy of nature. The second chapter of the second book of De Magnete opens with a characteristic onslaught upon the whole tribe of commentators, theologians and metaphysicians; or, perhaps more correctly, upon that variety of them who spent their lives in glossing one another's errors, or in spinning cobweb learning from their own brains and entangling their wits in self-contrived labyrinths. For especially keen reproach, however, are singled out the modern authors who had written about amber and jet because they had contented themselves with stating the attractive qualities in an occult way and never presented any experimental proof of them. This is sweeping enough to include Fracastorio, but whether it properly applies to Cardan, who, however occult he might have been in describing other things, was undeniably explicit and straightforward in his description of the amber (and who, moreover, in his De Subtilitate, makes a strong plea for more experimental proof than was customary among his congeners), may be fairly questioned. But, as Gilbert had evidently determined not to recognize Cardan in the matter of the diamond discovery, the casting of him into outer darkness, in respect to more debatable achievements, was not difficult. Hence, he makes no reservations in favor of the Italian or of any one else. All are embraced in one inclusive "they."

The famous announcement which begins the modern science is as follows:

"For not only amber and jet, as they think," he says, "attract corpuscles, but so also do (and now he sets first foot upon the great new field which still stretches so far before us) the diamond, the sapphire, the carbuncle, the iris stone, the opal, the amethyst, the vincentina, the English gem or Bristol stone, the beryl, rock crystal, glass, false gems made of crystal or paste glass, fluor spars, antimony, glass, belemnites, sulphur, antimony glass, mastic, lac sealing wax, hard resin, orpiment, rock salt, mica and rock alum."

It was an astounding discovery-this prevalence of the amber-soul. It meant that the spirit which men, through all ages, had supposed locked in the amber along with the dead flies and bees there imprisoned, had never been so confined. This was an Ariel which had not been bound in the cleft pine, now at last set loose by the magician's hand, but a sprite which had always been free to play a part among the things of heaven and earth undreamt of in man's philosophy. But Gilbert was no poet, nor ever "waxed desperate in imagination." Even when his inner vision pictured the eternal motion of the rolling spheres, their silent music never reached his thought. Besides, in the present instance, he was vitally concerned with the bedevilments of his theory, which seemed likely to follow; and a clear, practical and definite understanding of the physical cause was what he needed, and least of all any befogging of it by poetic imagery or idealization.

What could be more different than the substances which this force seemed to animate-what more contrasting than sulphur and the sapphire—or the true gems and the false? There were no such dissimilarities between the various kinds of lodestone, or even between the lodestone and the iron; so that the attracting capacity possessed by these involved no great diversity of substance. But here was attraction existing in bodies so totally unlike that to assert that all of them contained a primordial terrene magnetic Matter, would be to ascribe to that assumed substance a Protean capacity for change which would virtually argue it out of existence.

It was plain, therefore, that the amber quality was not something exceptional pertaining to the resin, but depended upon some cause hitherto unrecognized yet widely prevalent. Equally plain was it also to Gilbert, that so far from the difficulties of bringing this phenomenon into harmony with his magnetic hypothesis being diminished by the discovery of such prevalence, they were so greatly magnified as to render the effort obviously futile. A few

THE AMBER PHENOMENON.

301 years earlier it would have been easy to attribute everything troublesome to the influence of the stars or any other "occult" control, and, in fact even then, books on "the miracles of nature" jostled the commentaries on Aristotle on the shelves of every philosopher. But nothing could have been more repugnant to Gilbert than such a course. The amber effect, he saw, must be accounted for, and now, by an hypothesis which would be consistent with, though different from, the broad theory which, at all hazards, was to be maintained. Such was the path which now opened before Gilbert.

Far back in medieval times there arose that curious divagation of the human mind, based, perhaps, in some degree, on the ascendency of the Aristotelian philosophy of words, of seeking to explain things not understood by giving to them new names. Later, this was carried to extremes by Paracelsus, and the same course has since been followed by charlatans generally. It was also in Gilbert's day the custom of the alchemists, and, to some extent, that of all scientific students, to hide discoveries and modes of operation in arbitrary words and phrases, often the merest gibberish, of which only the users knew the meaning. Thus there came into existence a pedantic terminology.

"A Babylonish dialect which learned pedants most affect,"

which invaded every department of knowledge and which, in some branches of science, though much modified and more logically conceived, still flourishes.

Gilbert, from his own professional experience, was well aware of the dangers which word-manufacture involved on the one hand, and the temptations which it offered on the other; for, no matter how sure his experiments and welldemonstrated his arguments, the necessary learning of a new vocabulary would be almost an insurmountable barrier to the very minds to which his appeal lay from the schoolmen and philosophants. But when he unearths

matters that are genuinely hidden, and which must be identified somehow in speech, by marks which enable them to become the subjects of discourse, Gilbert has no hesitation in naming them, and the orbs "of virtue" and "of coition" already alluded to, are instances of such designations. These, with something of the same care which is found in the definitions of terms used in a modern British Act of Parliament, he groups together and elucidates in a separate and commendably brief glossary prefixed to his De Magnete.

The discovery of many substances partaking of the amber quality raised at once the need of a generic term including and fairly describing all, by which they might be spoken of and thought about without repetition and circumlocution. The property which all had in common was that of attracting corpuscles. And this attraction was not similar to that of the lodestone, but similar to that of the amber: similar, because, whatever its true cause might be, it was certainly ostensibly exerted in like manner to the amber attraction. Gilbert's treatise being in Latin, he frequently translates the English word "amber" by the Latin "electrum "-a derivative from the Greek тpov-and, on this basis, originates the term for the new genus. The word which he so coins is "Electrica "-translatable as "electrics"-which he defines as signifying "quae attrahunt eadem ratione ut electrum" (those substances which attract in the same manner as the amber). Thus the father of the science—by right of paternity-gave to it its name; for the subsequentlyinvented word "electricity" simply refers to the condition or state prevailing in an electric.1

I have now to outline the course of Gilbert's experimenting and the principal results which he achieved. Trying his electrics on many different substances, he soon reaches the conclusion that they will all attract, not only

'Further on I have noted the origin of other similarly derived words such as "electrical," etc.

GILBERT'S ELECTROSCOPE.

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straws and chaff, but metals, woods, leaves, stones, earths, even water and oil-"everything which appeals to the senses"-provided it be not aflame or in a too rarefied state. He is working from the vantage-ground of the isolated facts observed by others, and thus he moves beyond the implication of Fracastorio that the amber attracts only "hairs and twigs," and incidentally seizes a congenial opportunity to anathematize Alexander of Aprodiseus for drawing an absurd conclusion to the effect that the resin exercises an occult selection in attracting only the stalks and not the leaves of the garden-basil. In like manner he passes beyond the bounds of Cardan's discovery that the amber attraction may be cut off, and shows that a screening effect happens on the interposition of moist breath, a current of humid air, a sheet of paper, water, linen cloth, and the silk gauze known as "sarsnet."

He is not satisfied with merely stating that he has

GILBERT'S ELECTROSCOPE.1

proved all this by actual experiment. So anxious is he to avoid even the appearance of the prevailing mysticism, so careful to forestall any possible charge of concealing his mode of operating, so Faraday-like in his desire to leave behind him his ladder for the use of others to come, that he invites a repetition of his tests and a reverification of conclusions, and describes the simple apparatus which he has employed. He calls it a versorium-in modern terms it is an electroscope-made of a light metal rod centrally poised on an apex like the needle of a compass. It turns to the rubbed electric when the latter is brought near its

From the first edition of Gilbert's treatise De Magnete.