act of inhibition of either one or the other of these sets, or of both. The great function of volitional movements is, therefore, spread about in the encephalon, each half of which is sufficient for the performance of that function in both sides of the body.

XIV. Of all localizations of function in the brain none has ever been so completely and so universally admitted, and none, also, has been so generally abandoned, as that of the power of breathing in the medulla oblongata. The same arguments that I have employed against all other cluster-localizations in the brain, I made use of long ago against the location of the respiratory power in a part of the medulla. On the one hand, irritations in a good part of the encephalon, especially the base and the cerebellum and also in the spinal cord, can inhibit breathing at once. On the other hand, breathing may persist even after the destruction of the whole encephalon and even of a part of the cervical spinal cord. The nervous center for respiratory movements belongs to cells diffused in the base of the brain (including the whole medulla) and in the upper part of the spinal cord.

XV. Most physiologists are now gradually giving up the strict cluster-localizations which have been for many years accepted by them. Being little inclined to recognize that they had been misled or have made mistakes, they try to escape in supposing that if a function does not disappear when its pretended center is destroyed, it is owing to the fact that other parts of the brain are able to perform that function. In the same way they explain that if speech, sensibility, volitional movements, return, after having been lost, owing to a local lesion. in one hemisphere, this is due to the fact that the other hemisphere acts in place of the diseased one. That such may be the case, in a measure, I do not deny; but what I consider as true and established is, first, that the various mental and physical functions of the brain are localized in nerve cells so arranged that those employed for the same function, instead of being agglomerated together, are scattered about in many parts; secondly, that each half of the brain contains centers for all the cerebral functions, physical or mental.

C. E. BROWN-SÉQUARD.

THE DAWN OF ELECTRICITY.

THERE lies, at this writing, before me a Latin translation of the "Lives of the Philosophers," by Diogenes Laertius, bearing on its colophon the imprint of Octavianus Scotus, Venice, and the date of 1490. It contains, among other memoirs, the life of Thales of Miletus, one of the so-called seven wise men of Greece, and there appear, in the curious characters of the early printers, two lines which, freely translated, read thus:

"But Aristotle and Hippias say that he attributed souls also to lifeless things, forming his conjecture from the nature of the magnet and of amber."

Thales lived six hundred years before the Christian era; and while he was not the first to observe the attractive quality either of the magnet or of amber, for he learned the fact from the Egyptians, he at least invented the general theory of the "souls in lifeless things," and of the "amber soul" in particular. The sentence which I have quoted, however, relates both to the fact that the magnet and the amber will attract light bodies, and to the only theory extant to account for the peculiarity of amber; and thus it may be said fairly to represent all the knowledge of this strange phenomenon which the world possessed at the time of Thales, and to which, so far as related to the amber, nothing was added during the twenty centuries following.

There is some evidence that the ancients knew that a certain stone termed the "lyncurium," and supposed to be either the hyacinth or the tourmaline, would, when heated, behave like amber; but the old writings are contradictory and conjectural, and the phenomena described do not, in many respects, tally with the results of modern observation. So also, at some period, jet was found to act similarly to amber when rubbed; but how or when this was discovered, or, indeed, whether jet, often called "black amber," was not generically included in the "electrum" or "succinum" of the early writers, may be open to discussion.

It is important to distinguish between the knowledge of the ancients concerning natural phenomena which we now know to be electrical, and their acquaintance with the magnet and with amber-a source apparently of much confusion in the minds of many historians of electricity. There are countless traditions based on the lightning stroke, many of them as fantastic as ever romancer conceived. Tullus Hostilius is reputed to have been killed while essaying the role of Franklin, although Numa Pompilius, before him, is asserted already to have invented the lightning-rod. Earlier still, Prometheus is said to have brought down the electrical fire. There are writers who claim that the temple of Jerusalem was as well provided with lightning-rods as any modern building, and that a temple of Apollo was equally well protected by its encompassing laurels; that one Porsenna anticipated the modern idea of execution by electricity, by conducting the lightning to the territory of Volsinium, and there, by its aid, killing a devastating monster; that the vestal fire was kindled by lightning; that Moses was an electrician and another prototype of Franklin; and when we reach the dense ignorance of the dark ages, these and other like stories assume such prodigious and multiplied shapes that one wonders how the small modicum of truth which has formed the foundation of the present great science escaped being hopelessly crushed out of existence.

So, also, a distinction must be drawn between what was known in ancient times concerning the properties of the loadstone and what was known about the properties of rubbed amber. The ancients assumed that a like demon produced like effects in both. Here, again, modern writers have erred by ascribing to them knowledge of the correlation or interconvertibility of electricity and magnetism, forgetting that this was brought to light only by the discoveries of Arago and Faraday during the present century. The electrical knowledge of antiquity was restricted to the phenomenon presented by rubbed amber, and the theory of the amber soul proposed to explain it; but this, albeit the merest spark, maintained its existence for two thousand years before the breath of genius kindled it to flame.

The Venetian edition of the Greek historian grew ancient. In course of nature all men living when it came from the press

passed away. Still this same sentence continued to represent the sum of human learning in the science, and the unthought-of generation found itself no wiser, and, concerning the strange soul hidden in the yellow depths of the amber, speculating as hopelessly as the forgotten dust in its graveyards had done a century before. But then the times had changed, and with them the whole drift of human thought and activity. The reign of Elizabeth in England was drawing to its close. The menacing specter of the Spanish invasion, vanishing amid the wreck of the Armada, had left the people free to turn to other things than war and statecraft; to think, in fact, of themselves and for themselves. The liberated energy was manifesting itself on every side. The restless adventurers of Britain were penetrating unknown regions and circumnavigating the globe itself. From the realms of fancy English poets were bringing forth all-surpassing treasure. English philosophy, for the infinitely attenuated virus of theory and speculation which had permeated the schools down through generation after generation, was about to substitute the questioning of nature, to replace the "philosophy of words" with the "philosophy of works."

But "Franciscus Bacon sic cogitavit," had not yet been said. The last year of the sixteenth century had seen the gallant, vain, and foolish Essex hounded to his death by the eloquence of the advocate whom he had rescued from penury and the sponginghouses of Conduit Street; but the hand which penned the labored apology for that shameless work did not write the "De Augmentis" until half a decade later. It is said that remorse following upon the death of Essex hastened in the queen the beginning of that slow physical decadence which ended her life. If so, then, looking back upon this episode and upon the great actors who took part in it, we can dimly discern among them the presence of another player, albeit he stands in the shadow and we do not hear his voice. But his hand is on the failing pulse of the queen; he cautions against the excesses of the royal progress; he mingles the potion that fills the golden cup, which, the chronicler saith, she often put to her lips; he stands gravely silent, powerless to check the inroads of the "strange melancholy" which beset her; and when that life "so great, so strange

and lonely in its greatness, passed quietly away," William Gilbert, wise and faithful physician, turned from that bedside, broken-hearted, and went home to die.

This was the man who created the modern science of electricity, and gave to it "a local habitation and a name.'

William Gilbert was born in the year 1540, in the parish of Colchester, and "was accounted the chief person thereof." He was educated at Cambridge, gained a fellowship, made the grand tour, and returned to England a doctor in medicine, having obtained his degree from a foreign university. He became a member and finally President of the Royal College of Physicians in London, in which city he taught and practiced his profession for some thirty years, achieving such eminence that the queen appointed him her physician. "Such his loyalty to the queen," says old Thomas Fuller, "that as if unwilling to survive her he died in the same year with her, 1603;" and the same writer lovingly speaks of him as having "the clearness of Venice glass without the brittleness thereof, soon ripe and long lasting in his perfections."

In the year 1600 was published Gilbert's great treatise, "De Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure: Physiologia Nova Plurimis et Argumentis et Experimentis Demonstrata." If titles are to be indicative of contents, never had book an apter title, nor one better calculated to excite the keenest curiosity. Never before had "magnetic bodies," nor that "great magnet the earth," been heard of; never before had "experiments" been appealed to as the sole basis for a new physiology. It was the blast of the trumpet before the walls of the Jericho of second-hand philosophy, and they tottered and crumbled before it. "Facile est hominibus ingenio acutis absque experimentis et usu rerum labi et errare,” he says. His object is "to arrange facts founded on trials of the properties of natural things, to give to my subject demonstrations similar to those adopted in geometry, which, on the most simple foundation, raises the most magnificent works."

The Platonists, who taught that geometry was degraded when