Petrography rock was affixed to a microscope slide and then ground so thin that light could be transmitted through mineral grains that otherwise appeared opaque. The position of adjoining grains was not disturbed, thus permitting analysis of rock texture. Thin section petrography became the standard method of rock study. Since textural details contribute greatly to knowledge of the sequence of crystallization of the various mineral constituents in a rock, petrography progressed into petrogenesis and ultimately into petrology. It was in Europe, principally in Germany, that petrography advanced in the last half of the nineteenth century. The macroscopic characters of rocks, those
(What Is) Love? the internet on April 20, 2013. According to Jessica Sager of PopCrush, it picks up where the original song left off. Sager wrote that the song "likely isn't about [Marc] Anthony — but for those new to the song, it's surely easy to interpret it as such. Lopez gets pretty revealing in the new song, addressing a divorce directly and explicitly". Credits adapted from the liner notes of "Love?". (What Is) Love? "(What Is) Love?" is a song recorded by American entertainer Jennifer Lopez. Originally entitled "What Is Love?", the song appeared on the soundtrack to "The Back-up Plan" (2010),