driven from Venice after they had refused to comply with the statutes passed by the state in contravention and defiance of the Pope's interdict. The rancor against him, which resulted in an attempt to assassinate him, and the removal of his remains nine times from place to place before they found safe and permanent sepulture, had not undergone the slightest abatement when the Jesuit Cabæus,' six years after Sarpi's death, wrote his book on the magnet, and with ingenious indirection, proceeded to ascribe to Leonardo Garzoni, another Jesuit who died in 1592, the discoveries of which, as I shall shortly show, John Baptista Porta obtained knowledge directly from Sarpi.

Garzoni seems to have written, at some indefinite time (but very close to and possibly even after the periods when Sarpi made his researches), a treatise on the magnet which he left uncompleted. His brother, after his death, announced an intention of publishing it, but if he did so, Bertelli' (despite a thorough search through all the principal libraries of Italy and especially through those in which Cabæus found his literary material), has been unable to discover any trace of it. He unearths, however, a book, published in 1642, which says that Garzoni's magnetic discoveries were well known, and on no better basis than this, permits himself to accept, without question, the assertion of Cabæus that the whole idea of the field of force originated with Garzoni, and hence, by necessary implication, not with Sarpi. But against the tacit opinion of even so learned a scholar as Father Bertelli, stands the total lack of evidence in favor of Garzoni, and the intense antagonism to Fra Paolo characteristic of the Jesuits, in which Cabæus evidently shares.

While, however, as I have stated, proof of Sarpi's discoveries, based on his own writings, is now meagre, it

1

1 Philosophia Magnetica. Ferrara, 1629, lib. i., c. xvi.

2 Mem. sopra Peregrinus, 24.

is probable that, through the intervention of Baptista Porta, we have always been in full possession of a record of his work: in fact, we may not unreasonably assume, of a better one than such as may have been contained in the brief treatise which was burned: for Porta has told in extenso matters which Sarpi (who seems to have been the prototype of Faraday in his predilection for reducing his results to brief paragraphs and numbering them) would have reported in the most concise and abbreviated form.

John Baptista Porta was a prodigy. He died in 1615 at the reputed age of seventy, the author of many discoveries and many books—the last not all philosophical and scientific, for he is said to have written "fourteen comedies, two tragedies and one tragi-comedy." Despite some confusion and discrepancies in dates, it appears to be the fact that he produced his work on Natural Magic, in four books,' when only sixteen years of age. It bears the date of 1558, and deals learnedly with astrology, abounds in the wildest vagaries on the generation of animals, discusses agriculture and horticulture in similar manner, ends with an omnium gatherum on domestic economy, and has not, from first to last, a word about the lodestone. Despite his tender age, Porta seems to have been the moving spirit in what was probably a ridotto or club of persons interested in one another and in some especial subject, which met for purposes of discussion and mutual entertainment. Whatever the precise nature of the assemblage originally may have been, it developed finally into the first of all learned societies, the Academia Secretorum Naturæ abbreviated ordinarily into "the Segreti," in which it was an essential condition of membership that the

1Magiæ Naturalis, sive De Miraculis Rerum Naturalium, lib. iv. Io. Baptista Porta Neapolitano Auctore. Neapoli, 1558. Io. Baptista Portæ Neapolitani: Magiæ Naturalis, libri xx. Neapoli, 1589. There have been many editions in translations.

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applicant should have successfully prosecuted an original research in medicine or philosophy. It is said that, because the participators called themselves the "Otiosi" (idle, lazy), the people became aroused and denounced the organ

ization to the Pope as a gang of sorcerers; but it is a much more reasonable assumption that the astonishing statements in Porta's book, on such subjects, for example, as the production of birds and frogs from decaying matter,

had more to do with the indictment than any name which the members might have chosen to assume. In fact, scores of such societies-mainly literary-were organized in Italy before the close of the sixteenth century. Tiraboschi gives a list of one hundred and seventy-one of them, and among their designations were such singular names as “Inflammable," "Pensive," "Intrepid,” “Unripe," "Drowsy," "Rough," "Dispirited," "Solitary,' Fiery," "Sympathetic," "Grieved," "Re-ignited" and "Drunken."

At all events, Porta, as head and front of the offending, was summoned to Rome, whence he escaped with no worse penalty than the dissolution of his society and some fatherly advice, which indicated the extreme imprudence of ever starting it again. While at Rome he gained the favor of Cardinal Luigi D'Este, who gave him means of traveling through France and Spain, and who afterwards called him to Venice to build for him a parabolic mirror.

By this time Porta's attainments had gained him considerable celebrity. He had studied optics closely, and, although he did not invent the camera obscura (which was the work of Leon Baptista Alberti nearly a century earlier),' he first pointed out and taught the analogy between that apparatus and the human eye. He probably originated the magic lantern, however, and had some notion of the telescope, although his reference thereto is by no means unambiguous.

That the most eminent natural philosopher of Naples should have encountered the most eminent natural philosopher of Venice, and that the two should find in one another mutual attraction, seems to have inevitably followed. Porta instantly assumed the role of pupil, as most men did who came in contact with Sarpi, whatever their callings or attainments might be; and Sarpi, who delighted in teaching, found in Porta a congenial and tireless disciple. Nor did this relation cease even after great honors

1 Tiraboschi: Storia della Lett. Ital. Firenze, 1810, vol. vii., 495.

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had come to the Venetian; for when, as Procurator of his Order, he made an official visitation to Naples, it was with Porta that he sojourned, and into Porta's eager ears poured the story of the magnetic researches which he had then just completed. The Neapolitan had reached middle age, and for thirty-five years had been collecting material to add to the work on Natural Magic. Perhaps he deemed this latest teaching of Sarpi the cap-sheaf of all, and an indication that the auspicious time for publication had come. He had been admitted to the great Academy of the Lyncei, and, shrewdly considering that nothing issued under such sanction would be taken as savoring of the black art, he induced that society to give the work, now extended to twenty books, its official approval. This completed. edition appeared in 1589. The seventh book is devoted wholly to the magnet, and is one of the longest in the volume. Cabæus intimates that it is merely an epitome of knowledge gained by Porta from Garzoni; and Bertelli, perceiving the necessity of bringing the two men at least into geographical proximity, thinks that Porta may have met the Jesuit when he went to Venice to make the Cardinal's mirror.

But this is disposed of by Porta himself, who, in his preface to his book on the magnet, says "We knew among the Venetians Paulus Venetus, vigilant in this study. He was of the order of Serviti, then a Provincial, now most worthy Procurator, from whom we not only do not blush to have copied, but we rejoice therein, since we know no one than he more learned or more subtle among those that we have seen. He was born to universal knowledge, and is an ornament not merely to the city of Venice and to Italy, but to the world. If we begin from his fundamental ideas and proceed to his completed studies of transcendent sublimity and accurate labor, we shall never be disappointed." Sarpi was Provincial of his order from 1579 to 1582, so that, at the time Porta's work appeared, the two men must have been in communication for more than seven years.