In Greek or Latin prosody, the replacement of a prosodic element that is required or expected at a given place in a given metre by another which is more or less equivalent in temporal quantity. In modern prosody, substitution refers to the use within a metrical series of a foot other than the prevailing foot of the series. A silence may also replace expected sound and
During the caliphate of 'Abd al-Malik ibn Marwan (ruled 685–705), which followed the end of the second fitnah, and under his successors during the next four decades, the problematic consequences of the conquests became much more visible. Like their Byzantine and late Sasanian predecessors, the Marwanid caliphs nominally ruled the various religious communities but allowed the
Mineral, an interstratified mixture of kaolinite and free silica. See kaolinite.
Olivine mineral found only in iron-manganese ore deposits and skarns and in metamorphosed manganese-rich sediments, such as those of Cornwall, Eng., and Franklin, N.J., in the United States. Tephroite (manganese silicate; Mn2SiO4) forms a solid solution series with the olivine fayalite in which iron completely replaces manganese in the molecular structure. Minerals intermediate
