Malus Malus Malus ( or ) is a genus of about 30–55 species of small deciduous trees or shrubs in the family Rosaceae, including the domesticated orchard apple ("M. pumila" syn. "M. domestica" ) – also known as the eating apple, cooking apple, or culinary apple. It is dealt with under Apple. The other species are generally known as crabapples, crab apples, or wild apples. The genus is native to the temperate zone of the Northern Hemisphere. Apple trees are typically tall at maturity, with a dense, twiggy crown. The leaves are long, alternate, simple, with a serrated margin. The flowers
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 –