20th century in science biologically relevant molecules, they were, till the end of the 20th century, more a collection of rules, observations, and recipes than rigorous ab initio quantitative methods. This heuristic approach triumphed in 1953 when James Watson and Francis Crick deduced the double helical structure of DNA by constructing models constrained by and informed by the knowledge of the chemistry of the constituent parts and the X-ray diffraction patterns obtained by Rosalind Franklin. This discovery lead to an explosion of research into the biochemistry of life. In the same year, the Miller–Urey experiment demonstrated that basic constituents of protein, simple amino acids,
Rudolf Signer from the Thymus of calves, of which he took 15 grams of extraordinarily pure DNA to London. In England he gave it to various scientists, among them Maurice Wilkins, in order to promote research in the field. The analysis of X ray images of these DNA samples in Wilkins' laboratory allowed James Watson and Francis Crick to discover the double-helix structure of DNA. Rests of the DNA which Signer brought to England, survive today in the collection of King's College, London. Over 250 of Signer's scientific writings were published during his lifetime. The Lavoisier Medal was awarded to him for