Ceratonia siliqua harubh. "Ceratonia siliqua", the scientific name of the carob tree, derives from the Greek "kerátiοn" κεράτιον 'fruit of the carob (from "keras" κέρας 'horn'), and Latin "siliqua" 'pod, carob'. The unit "carat", used for weighing precious metal and stones, also comes from κεράτιον, as alluding to an ancient practice of weighing gold and gemstones against the seeds of the carob tree by people in the Middle East. The system was eventually standardized, and one carat was fixed at 0.2 grams. In late Roman times, the pure gold coin known as the "solidus" weighed 24 carat seeds (about 4.5 grams). As
Pure subgroup While pure projective modules have not found as many applications as pure injectives, they are more closely related to the original work: A module is pure projective if it is a direct summand of a direct sum of finitely presented modules. In the case of the integers and Abelian groups a pure projective module amounts to a direct sum of cyclic groups. Pure subgroup In mathematics, especially in the area of algebra studying the theory of abelian groups, a pure subgroup is a generalization of direct summand. It has found many uses in abelian group theory and related areas. A