Langlet was born in
Södertälje, Sweden. He was the son of architect
Emil Victor Langlet (1824–1898) and his wife, author Clara Mathilda Ulrika Clementine Söderén (1832–1904). His brothers included author
Valdemar Langlet (1872–1960). Langlet stated "Obstructed by other work, however, I had to postpone this investigation for a couple of weeks and had just begun it when the news reached Prof. Cleve that helium had been found [by Ramsay] in cleveite.... I continued the investigation I had begun in the hope of obtaining a product that differed from Ramsay's at least to some extent through possible differences in starting material and method of preparation." Although Langlet cannot be credited as an independent discoverer of the element
helium, he was the first to correctly measure its
atomic weight. He died in
Gothenburg, Sweden. ==References==