Maslama al-Majriti

Abu al-Qasim Maslama ibn Ahmad al-Majriti (Arabic: أبو القاسم مسلمة بن أحمد المجريطي: c. 950–1007), known or Latin as Methilem, was a Muslim Arab[1][2][3][4] astronomer, alchemist, mathematician, economist and Scholar in al-Andalus, active during the reign of Al-Hakam II.

[5] Al-Majrīṭī took part in the translation of Ptolemy's Planisphaerium, improved existing translations of the Almagest, introduced and improved the astronomical tables of Muhammad ibn Musa al-Khwarizmi, aided historians by working out tables to convert Persian dates to Hijri years, and introduced the techniques of surveying and triangulation.

He built a school of Astronomy and Mathematics and marked the beginning of organized scientific research in al-Andalus.

Both were translated into Latin, in a version somewhat bowdlerised by Christian dogma, in 1252 on the orders of King Alfonso X of Castile; the original Arabic text dates probably from the middle of the eleventh century.

The Rutbat includes alchemical formulae and instructions for purification of precious metals, and was also the first to note the principle of conservation of mass, which he did in the course of his pathbreaking experiment on mercury(II) oxide: I took natural quivering mercury, free from impurity, and placed it in a glass vessel shaped like an egg.