printed, also translated into English in 1658, into French, Spanish, and other languages) ; F7ii/tognoionica (1583, a bulky treatise on the physiology of plants as then understood) ; De humana physiogno- monia, in six books (1591) ; Villa, in twelve books (1592 ; an inter esting practical treatise on fanning, gardening, and arboriculture, based upon his own observations at his country seat near Naples) ; DC rcfractionc, opticcs partc, in nine books (1593) ; Pneumatica, in three books (1601) ; DC ccelcsti physiognomonia, in six books (1601) ; Elcmenta curvilinca (1601) ; DC distillationc, in nine books (1604) ; De munitione, in three books (1608) ; and De acris transmutation- ibus, in four books (1609). Porta also wrote several Italian comedies (Olimpia, 1589 ; La Fantcsca, 1592 ; La Trappolaria, 1597 ; / Due Fratelli Rivali, 1601 ; La Sorclla, 1607 ; La Chiappinaria, 1609 ; La Carbonaria, 1628 ; La Cintia, 1628). Among all the above- mentioned works the chief interest attaches to the Magia naturalis, in which a strange medley of subjects is discussed, including the reproduction of animals, the transmutation of metals, pyrotechny, domestic economy, statics, hunting, the preparation of perfumes ; in book xvii. he describes a number of optical experiments. They include a description of the camera obscura. If, says he, a small aperture is made in the shutter of a dark room, distinct images of all external objects will be depicted on the opposite wall in their true colours ; and he further adds that, if a convex lens be fixed in the opening so that the images are received on a surface at the dis tance of its focal length, the pictures will be rendered so much more distinct that the features of a person standing on the outside of the window may be readily recognized in his inverted image. He applied this instrument to a sort of magic lantern, the representation of eclipses of the sun, and of hunting and other scenes, battles, and other events produced by movable pictures and drawings. He considered the eye as a camera obscura, the pupil as the hole in the window contracting and dilating with different lights, and the crystalline lens as the principal organ of vision, though he seems to have regarded it not as his convex lens but as the tablet on which the images of external objects were formed, the cornea being, no doubt, in his estimation, the part of the eye which formed the picture. After speaking of spectacles and the like, he professed to know a combination of lenses by which " we may contrive to recog nize our friends at the distance of several miles, and those of weak sight may read the most minute letters from a distance. It is an invention of great utility, and grounded on optical principles, nor is it at all difficult of execution ; but it must be so divulged as not to be understood by the vulgar, and yet be clear to the sharp- sighted." The obscure description which follows does not, how ever, make it at all probable that he had really anticipated Galileo.
In his De rcfractione Porta treats of binocular vision. He repeats the propositions of Euclid on the dissimilar pictures of a sphere when seen with each eye and when seen with both ; and he quotes from Galen on the dissimilarity of the three pictures thus seen. But, maintaining as he does that we can see only with one eye at a time, he denies the accuracy of Euclid s theorem ; and, while he admits that the observations of Galen are correct, he endeavours to explain them on other principles. In illustrating Galen s views on the dissimilarity of the three pictures he gives a diagram in which can be recognized not only the principle but the construction of the stereoscope. It contains a view, represented by a circle, of the picture of a solid as seen by the right eye, of the picture of the same solid as seen by the left, and of the combina tion of these two pictures as seen by both eyes, placed between the first two pictures. These results, as exhibited in three circles, are then explained by copying the passage from Galen, and he requests the observer to repeat the experiments so as to see the three dis similar pictures when looking at a solid column.
PORT ADELAIDE, South Australia. See vol. i. p. 151.
PORTADOWN, a market-town of Armagh, Ireland, is situated on the river Bann, and on the Great Northern Railway, 25 miles west -south -west of Belfast and 10 north-north-east of Armagh. The Bann, which is connected with the Newry Canal and falls into Lough Neagh about 5 miles north of the town, is navigable for vessels of 90 tons burden. It is crossed at Portadown by a stone bridge of seven arches, originally built in 1764, but since then re-erected. The town consists of a principal street, containing a number of good shops and houses, and with several streets inhabited by the working-classes branching from it at various points. The only public building of importance is the court-house and news-room. The manufacture of linen and cotton is carried on, and there is a considerable trade in pork, grain, and farm produce. The manor in the reign of Charles I. was bestowed on John Obyns, who erected a mansion and a few houses, which were the beginning of the town. A grain-market was established in 1780. The population in 1871 was G735, and in 1881 it was 7850.
PORTALIS, Jean Étienne Marie (1745–1807), French jurist and the principal author of the Code Civil, which as the Code Napoleon has been declared the greatest monu ment of the reign of the emperor, came of a bourgeois family, and was born at Bausset in Provence on 1st April 1745. He was educated by the Oratorians at their schools in Toulon and Marseilles, and then went to the university of Aix ; while a student there he published his first two works, Observatioiis sur mile in 1763 and Des Prejuycx in 1764. In 1765 he became an avocat at the parlement of Aix, and soon obtained so great a reputation that he was instructed by Choiseul in 1770 to draw up the decree authorizing the marriage of Protestants. From 1778 to 1781 he was one of the four assessors or administrators of Provence, and in 1783 he brought about the countess of Mirabeau s separation from her husband in spite of the impassioned pleading of the great Mirabeau himself. In 1788 he protested on behalf of the avocats of Aix against Lomenie de Brienne s May edicts, but in the following year, probably owing to Mirabeau s influence, he was not elected to the States- General. He entirely disapproved of the great changes brought about by the Constituent Assembly ; and, after refusing to be one of the royal com mission for splitting up Provence into departments, he retired, first to his country house and then to Lyons, and took no further part in politics. In November 1793, after the republic had been proclaimed, he came to Paris, and was thrown into prison, being the brother-in-law of Simeon, who was the leader of the federalists in Provence. He was soon removed through the influence of Barere to a maison de sante, where he remained undisturbed till the fall of Robespierre. On being released he practised as a lawyer in Paris; and in 1795 he was elected by the capital to the Council of Ancients, at once becoming a leader of the moderate party opposed to the directory. His reports, however, were chiefly on questions of law reform, and he commenced the labours which have made his name famous. As a leader of the moderates he was proscribed at the coup d etat of Fructidor, but, unlike Pichegru and Barbe-Marbois, he managed to escape to Switzerland, and did not return till Bonaparte became First Consul. Bonaparte knew his value, and made him a conseiller d etat in 1800, and then charged him, with Tronchet, Bigot de Preameneu, and Jacques de Maleville, to draw up the Code Civil. Of this commission he was the most industrious member, and many of the most im portant titles, notably those on marriage and heirship, are his work. In 1801 he was placed in charge of the depart ment of cultes, or public worship, and in that capacity had the chief share in drawing up the provisions of the Con cordat. In 1803 he became a member of the Institute, in 1804 minister of public worship, and in 1805 a knight grand cross of the Legion of Honour. He soon after be came totally blind ; and after undergoing an unsuccessful operation he died at Paris on 23d August 1807.
The work of Portalis appears in the Code Napoleon, but see also Frederick Portalis s Documents, rajytorls, ct travaux inedits sur le Code Civil, 1844, and Sur le Concordat, 1845 ; for his life, see the biography in the edition of his (Swires by F. Portalis, 1823, and Rene Lavollee, Portalis, sa vie et ses ceuvres, Paris, 1869.
