AQUATINT, a variety of etching (q.v.) in which effects are obtained by the action of acid through a porous ground of sand or some powdered resinous substance (Lat. aqua, water, and tincta, dyed). The plate is first covered with a ground over which the resinous powder or sand is evenly dusted by some mechani cal process, the portions of the plate which are to appear white when printed being covered with stopping-out varnish. The plate is then covered with the mordant which bites into the interstices between the minute particles and produces a granulated surface. The process is repeated and the different tones obtained by the varied depths to which the different portions of the plate are bitten. In theory therefore aquatint is not capable of producing even graduations of tint, but may be compared in effect to a contour map where each particular elevation is indicated by a flat tint ending abruptly. In skilful hands, however, the series of bitings can be so manipulated as to make these contours almost invisible; the process can be used in conjunction with etching, drypoint, mezzotint and crayon.
The invention of aquatint is generally credited to Jean Bap tiste Le Prince (1734-80, but there seems little doubt that some form of it was known and used almost loo years earlier. A certain Jan van de Velde seems to have combined aquatint with roulette work in some of his portraits about 1658. In the hands of F. Janinet, P. L. Debucourt and other French artists of the end of the i8th century the process was brought to a technical perfection which has never been surpassed. It was used by them, with extraordinary skill and success, as a vehicle for printing in colour. In England in the last quarter of the i8th century and the first half of the i9th century the method was used by such artists as Paul Sandby, Thomas Malton, the Daniells, R. Pollard, J. C. Stadler for reproducing water-colour drawings. English aquatints were not printed in colours, but were usually coloured by hand. The process during the latter part of the 19th century fell into disuse but was revived and successfully employed by Sir Frank Short, Theodore Roussel, Oliver Hall, W. Lee Hankey, W. P. Robins and others. (See ETCHING.) (A. E. P.) AQUAVIVA, CLAUDIO , fifth general of the Society of Jesus, the youngest son of the duke d'Atri, was born at Naples. He joined the Jesuits at Rome in 1567, and his ad ministrative gifts marked him out for the highest posts. He was soon nominated provincial of Naples and then of Rome; and during this office he offered to join the Jesuit mission to England that set out under Robert Parsons (q.v.) in the spring of 1580. The following year, being then only 37 years old, he was elected by a large majority general of the society in succession to Mer curian, to the great surprise of Gregory XIII. ; but the extraor dinary political ability he displayed and the vast increase that came to the society during his long generalate abundantly justified the votes of the electors. He, together with Lainez, may be re garded as the real founder of the society as it is known to history. A born ruler, he secured all authority in his own hands, and insisted that those who prided themselves on their obedience should act up to the profession. He successfully quelled a revolt among the Spanish Jesuits, which was supported by Philip II., and he made use in this matter of Parsons. A more difficult task was the management of Sixtus V., who was hostile to the society. By consummate tact and boldness Aquaviva succeeded in playing the king against the pope, and Sixtus against Philip. For pru dential reasons, he silenced Mariana, whose doctrine on tyranni cide had produced deep indignation in France; and he also appears to have discountenanced the action of the French Jesuits in favour of the League, and was thus able to secure solid advantages when Henry IV. overcame the confederacy.
To him is due the Jesuit system of education in the book Ratio atque institutio studiorum (Rome, 1586). But the Dominicans denounced it to the Inquisition and it was condemned both in Spain and in Rome, on account of some opinions concerning the Thomist doctrines of the divine physical premotion in secondary causes and predestination. The incriminated chapters were with drawn in the edition of 1591. In the fierce disputes that arose between the Jesuit theologians and the Dominicans on the subject of grace, Aquaviva managed, under Clement VIII. and Paul V., to save his party from a condemnation that at one time seemed probable. He died at Rome, Jan. 31 1615, leaving the society numbering 13,000 members in 55o houses and 15 provinces. The subsequent influence exercised by the Jesuits, in their golden age was due largely to the far-seeing policy of Aquaviva, who was undoubtedly the greatest general that has governed the society.