Degaussing Research Articles

The Earliest Printed Book on the Magnet

THE annotated catalogues of antiquarian booksellers who deal especially in old scientific books always make interesting and instructive reading to the student of the history of science. Sometimes these catalogues form the medium for the first announcement of bibliographical discoveries of importance. A case in point is afforded by a catalogue (No. 73) recently issued by Messrs. Davis and Orioli, of 37 Museum Street, London, W.C.I. In this list, there is offered for sale a book that the vendors claim to be the hitherto undescribed first printed text of Petrus Peregrinus's treatise “De Magnete”. The book in question, a small quarto of six leaves, is entitled “De Virtute Magnetis”, and its title page bears the name of Raymundus Lullus as author; but no date or place of printing is indicated. The text is almost identical with that of the edition of Peregrinus's treatise published at Augsburg in 1558, hitherto regarded by bibliographers as the first printed edition. The original “Epistola De Magnete” was written in the thirteenth century, probably in 1269, and several early MSS. copies exist. In a long and interesting note, Messrs. Davis and Orioli give reasons for believing the book they describe to have been printed at Rome by E. M. Silber, not later than the year 1520. They state that, in the past, Peregrinus's treatise has been ascribed both to Raymond Lull and to Roger Bacon, and it is suggested that these authors' names may have been used in a general way during the Renaissance as possible authors of any scientific works. While the 1558 edition is a book of extreme rarity, Messrs. Davis and Orioli have so far only been able to trace one other copy of “De Virtute Magnetis”, that in the Bibliotheque Nationale, Paris.

The Evolution and Present Status of Electrosurgery in the Treatment of Cancer

NOT the least interesting feature of the history of high frequency currents is the fact that much of the original experimentation was done by physicians. Ever since Dr. William Gilbert, surgeon to Queen Elizabeth, in 1600, published his work, “De Magnete,” and laid the foundations of our modern conceptions of electricity, physicists and physicians have been attracted to this great force and its possible service to man. Nearly two hundred years later Galvani, an Italian physician and a professor of anatomy, accidentally discovered the muscular contractions produced by the current to which he gave his name, and before the middle of the nineteenth century (about the time that Faraday was announcing his discovery of induction), Joseph Henry, an American, described the oscillatory character of the discharge from the Leyden jar. Henry not only understood the oscillatory nature of these waves, but proved experimentally that a spark about one inch in length from the prime conductor of an electrical machine to a wire circuit in an upper room produced inductive effects capable of magnetizing needles in a parallel circuit placed in the cellar, although this was thirty feet below the upper floor and separated from it by two floors each fourteen inches thick. This demonstration did not attract further attention until it was taken up by Hertz in 1888, when he succeeded in producing a series of electric oscillations of very high frequency. D'Arsonval thereupon showed that muscular contractions cease with 10,000 oscillations per second and this number has been taken arbitrarily as the dividing line between currents of high frequency and low frequency. In his book, “History of Electrotherapy and Diagnosis,” Colwell says: “The actual production of heat within the tissues themselves as the result of the passage of an electric current of high frequency was first suggested by Nicola Tesla in 1891. D'Arsonval, in February of that year, made a communication to the Société de Biologie in which he stated the possibility of passing a high frequency current of three amperes through the body with no other sensation than that of heat.” Doyen, whose researches on the penetration of heat began in 1896, presented to the French Surgical Congress in 1907 a well conceived method of destroying accessible cancer by electrocoagulation. One of his important conclusions was, “Of all means employed in the destruction of pathological tissues the only certain method is that of heat.” In 1908, Nagelschmidt, at the Buda-Pesth Congress, demonstrated a specially designed apparatus for producing this heating effect and introduced the name “diathermy.” It is evident that although the use of the word “diathermy” at that time represented an effort at exactness, it is inadequate to-day to cover all that is being done with high frequency currents.

Book Review: Petrus Peregrinus de Maricourt and his Epistola de Magnete

Book Review: Petrus Peregrinus de Maricourt and his Epistola de Magnete

Gilbert's 'De Magnete'

Gilbert's 'De Magnete'

The First Magnetician

WHILE thanking you and “R. T. G.” for the exceedingly kind appreciation of the Gilbert Club's English translation of “De Magnete” (p. 249), I write to express the wish that the notice had mentioned the names of those who have collaborated in the production of this version. They are the late Mr. Latimer Clark, the late Sir B. W. Richardson, Rev. A. W. Howard, Prof. R. A. Sampson, Dr. Joseph Larmor, Sec. R.S., Prof. Meldola, F.R.S., Mr. Edward Little, Mr. G. T. Dickin and Rev. W. C. Howell. To the last-named a special recognition is due for indefatigable and critical care during the long final revision and press correction.

William Gilbert of Colchester: a Sketch of his Magnetic Philosophy

THE immediate occasion of the appearance of this little book is the issue to the subscribers of the Gilbert Club of the English translation of “De Magnete.” The author has attempted, and with real success, to show what manner of man Gilbert was, wherein lay his genius, what were his merits, and what also were his faults and failings. Mr. Benham dwells on the circumstance that, although Gilbert's actual discoveries were few and crude, he must be judged rather by the spirit of his work. “He was not the builder of sciences, but the architect of a truly scientific spirit; and his life-work consisted in the doctrine, new to England, that all scientific knowledge must be. founded on practical experiment and observation alone, instead of upon speculations and theories evolved out of inner consciousness.” The successive chapters of the book deal with the old magnetic philosophies, magnetic motions and electric force, the magnet's “directive virtue,” the variation of the compass, the dip and “orbes of virtue” of the magnet, the life of the Universe (in which Gilbert, although no Manichean, was clearly a believer) and the Copernican theory. The author is particularly happy in his treatment of this last topic; but throughout the analysis of Gilbert's work is accurate and discriminating. The book is illustrated with a picture of Gilbert's terrella, and another of his tombstone in the church of Holy Trinity, Colchester. William Gilbert of Colchester: a Sketch of his Magnetic Philosophy. By Charles E. Benham. Pp. 96. (Colchester: Benham and Co., 1902.) Price 2s. net.

William Gilbert of Colchester, Physician of London, on the Loadstone and Magnetic Bodies, and on the Great Magnet the Earth A New Physiology, Demonstrated with Many Arguments and Experiments

AMONG men of science there is no difference of opinion as to the value of the original Latin work, “De Magnete,” of which this is a translation. Some time ago (NATURE, vol. xlii. p. 279) we gave an account of a meeting held at Colchester by members of the Essex Field Club and the Gilbert Club, for the purpose of doing honour to the memory of Gilbert, who was born there in 1540. In a speech delivered at this festival Lord Rayleigh not only spoke highly of Gilbert's work, but went on to say that although we owe to an investigator who lived so long ago the theory that the earth is a great magnet, we are not much in advance of that position at the present time, as nobody has yet explained the origin of terrestrial magnetism. It was most desirable that a work which may be said to have marked a definite stage in the evolution of physical science should be presented in an English form, and this has now been done by an American scholar, who, as he himself explains, has “translated with latitude, keeping in view the author's sense more particularly than his words, and amplifying without altering the former.” Mr. Mottelay has also brought together in a short biographical memoir the leading facts relating to Gilbert's career. The volume is well printed on good paper, and will be very welcome to students of the history of scientific ideas.

A Study in Magnetism

THE name of Faraday will go down to posterity foremost amongst the names of the scientific men of this century, for the simple comprehensiveness and original beauty of his researches in electricity and magnetism; chiefly, perhaps, for his discovery of magneto-electricity—the kind of electricity that can be induced in conductors which are caused to pass near magnets. Those who have carefully read Faraday's works know how he was led to this discovery by the conception he had formed of magnetic force. Until his time magnetic attractions and repulsions had been explained as a kind of action-at-a-distance. Faraday explained them as the results of the action of the medium filling the intervening space; and he gave several indisputable proofs that the space surrounding a magnet was thrown into a peculiar condition by the presence of the magnetism. Two centuries previously another Englishman, as uniquely great if not greater, Dr. Gilbert, had in his famous treatise “De Magnete,” told how iron filings sprinkled on a piece of card beneath which a magnet lay, assumed certain mysterious lines. To these lines Faraday gave the name of lines of force, and showed that they represented, wherever they went, the direction and strength of experiment. In the volumes of his researches he filled several entire plates with drawings of the figures assumed by the lines under various combinations. They had taught him to anticipate magneto-electricity and electromagnetic rotation. He had diligently followed them up from the hint afforded by Dr. Gilbert's experiment with the iron filings. He had begun to apply the method to the investigation of the interaction of electric currents when the decay of age overtook him, and the research dropped from his grasp. Had he lived the study which the writer of the present article is about to narrate-would have been completed long ago.