bissextil

BISSEXTILE. The day which is added every fourth year to the month of 
February, in order to make the year agree with the course of the sun. It is 
called bissextile, because in the Roman calendar it was fixed on the sixth 
day before the calends of March, (which answers to the 24th day of 
February,) and this day was counted twice; the first was called bissextus 
prior, and the other bissextus posterior, but the latter was properly called 
bissextile or intersalary day. Although the name bissextile is still 
retained in its obsolete import, we intercalate the 29th of February every 
fourth Year, which is called leap year; and for still greater accuracy, make 
only one leap year out of every four centenary years. The years 1700 and 
1800 were not leap years, nor will the .year A. D. 1900 be reckoned as one, 
but the year A. D. 2000 will be a leap year or bissextile. For a learned 
account of the Julian and Gregorian calendars, see Histoire du Calendrier 
Romain, by Mons. Blondel; also, Savigny Dr. Rom. Sec. 192; and Brunacci's 
Tract on Navigation, 275, 6. BLACK ACT, English law. An act of parliament 
made in the 9 Geo. II., which tears this name, to punish certain marauders 
who committed great outrages, in disguise, and with black faces. See Charlt. 
R. 166.