Malus sieversii Malus sieversii Malus sieversii is a wild apple native to the mountains of Central Asia in southern Kazakhstan. It has recently been shown to be the primary ancestor of most cultivars of the domesticated apple ("Malus pumila"). It was first described (as Pyrus sieversii) in 1833 by Carl Friedrich von Ledebour, a German naturalist who saw them growing in the Altai Mountains. It is a deciduous tree growing to , very similar in appearance to the domestic apple. Its fruit is the largest of any species of "Malus" except "pumila", up to 7 cm diameter, equal in size to many
Étienne-Louis Malus index between the surface and the interior of the glass). It was not until 1815 that Sir David Brewster was able to experiment with higher quality glasses and correctly formulate what is known as Brewster's law. This law was later explained theoretically by Augustin Fresnel, as a special case of his Fresnel equations. Malus is probably best remembered for Malus's law, giving the resultant intensity, when a polariser is placed in the path of an incident beam. His name is one of the 72 names inscribed on the Eiffel tower. Étienne-Louis Malus Étienne-Louis Malus (; ; 23 July 1775 –