(P. G. K.)
DONATI, GIOVANNI BATTISTA (1826-1873), Italian astronomer, was born at Pisa on the 16th of December 1826. He entered the observatory of Florence as a student in 1852, became assistant to G. B. Amici in 1854, and was appointed in 1864 to succeed him as director. A new observatory at Arcetri near Florence, built under his supervision, was completed in 1872. During the ten years 1854-1864 Donati discovered six comets, one of which, first seen on the 2nd of June 1858, bears his name (see [Comet]). He observed the total solar eclipse of the 18th of July 1860, at Torreblanca in Spain, and in the same year began experiments in stellar spectroscopy. In 1862 he published a memoir, Intorno alle strie degli spettri stellari, which indicated the feasibility of a physical classification of the stars; and on the 5th of August 1864 discovered the gaseous composition of comets by submitting to prismatic analysis the light of one then visible. An investigation of the great aurora of the 4th of February 1872 led him to refer such phenomena to a distinct branch of science, designated by him “cosmical meteorology”; but he was not destined to prosecute the subject. Attending the International Meteorological Congress of August 1873 at Vienna, he fell ill of cholera, and died a few hours after his arrival at Arcetri, on the 20th of September 1873.
See Vierteljahrsschrift der astr. Gesellschaft (Leipzig), ix. 4; Monthly Notices Roy. Astr. Society, xxxiv. 153; Memorie degli spettroscopisti italiani, ii. 125 (G. Cacciatore); Nature, viii. 556; &c.
(A. M. C.)
DONATIO MORTIS CAUSA (grant in case of death), in law, a gift of personal property made in contemplation of death and intended either expressly or impliedly to take complete effect only if the donor dies of the illness affecting him at the time of the gift. The conception as well as the name is borrowed from Roman law, and the definition given by Justinian (Inst. ii. 7. 1) applies equally to a donatio mortis causa in Roman and English law. A distinction, however, has arisen between the English and civil codes; by English law delivery either actual or (when from the nature of the thing actual delivery is impossible) constructive is essential, and this delivery must pass not only the possession but the dominion of the thing given; by the civil law, in some cases at least, delivery of possession was not essential (see the judgment of Lord Chancellor Hardwicke in Ward v. Turner, 1751, 2 Ves. sen. 431, where the whole question is exhaustively discussed). A donatio mortis causa stands halfway between a gift inter vivos and a legacy, and has some of the characteristics of each form of disposition. It resembles a legacy in that (1) it is revocable during the donor’s life, (2) it is subject to legacy and estate duty, and (3) it is liable to satisfy debts of the testator in default of other assets. On the other hand, it resembles a gift inter vivos in that it takes effect from delivery; therefore the consent of the executor is not necessary. Anything may be the subject of a donatio mortis causa, the absolute property in which can be made to pass by delivery after the donor’s death either in law or equity; this will cover bankers’ deposit notes, bills of exchange, and notes and cheques of a third person, but not promissory notes and cheques of the donor in favour of the donee, for the donor’s signature is merely an authority for his banker to pay, which is revoked by his death.
DONATION OF CONSTANTINE (Donatio Constantini), the supposed grant by the emperor Constantine, in gratitude for his conversion by Pope Silvester, to that pope and his successors for ever, not only of spiritual supremacy over the other great patriarchates and over all matters of faith and worship, but also of temporal dominion over Rome, Italy and “the provinces, places and civitates of the western regions.” The famous document, known as the Constitutum Constantini and compounded of various elements (notably the apocryphal Vita S. Silvestri), was forged at Rome some time between the middle and end of the 8th century, was included in the 9th century in the collection known as the False Decretals, two centuries later was incorporated in the Decretum by a pupil of Gratian, and in Gibbon’s day was still “enrolled among the decrees of the canon law,” though already rejected “by the tacit or modest censure of the advocates of the Roman church.” It is now universally admitted to be a gross forgery.[1] In spite, however, of Gibbon’s characteristic scepticism on this point, it is certain that the Constitutum was regarded as genuine both by the friends and the enemies of the papal pretensions throughout the middle ages.[2] Though no use of it was made by the popes during the 9th and 10th centuries, it was quoted as authoritative by eminent ecclesiastics of the Frankish empire (e.g. by Ado of Vienne and Hincmar of Reims), and it was employed by two Frankish popes, Gregory V. and Silvester II., in urging certain territorial claims. But not till 1050 was it made the basis of the larger papal claims, when another Frankish pope, Leo IX., used it in his controversy with the Byzantines. From this time forward it was increasingly used by popes and canonists in support of the papal pretensions, and from the 12th century onwards became a powerful weapon of the spiritual against the temporal powers. It is, however, as Cardinal Hergenröther points out, possible to exaggerate its importance in this respect; a charter purporting to be a grant by an emperor to a pope of spiritual as well as temporal jurisdiction was at best a double-edged weapon; and the popes generally preferred to base their claim to universal sovereignty on their direct commission as vicars of God. By the partisans of the Empire, on the other hand, the Donation was looked upon as the fons et origo malorum, and Constantine was regarded as having, in his new-born zeal, betrayed his imperial trust. The expression of this opinion is not uncommon in medieval literature (e.g. Walther von der Vogelweide, Pfeiffer’s edition, 1880, Nos. 85 and 164), the most famous instance being in the Inferno of Dante (xix. 115):
| “Ahi, Costantin, di questo mal fu matre Non la tua conversion, ma quella dote Che da te prese il primo ricco patre!” |