DONATI, GIOVANNI EATTISTA Italian astronomer, was born at Pisa on Dec. 16, 1826. In 1854-64 he discovered six comets, one of which, first seen on June 2, 1858, bears his name (see COMET). On Aug. 5, 5864, he discovered the gaseous composition of comets by submitting to spectroscopic analysis the light of one then visible.
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.