Lapworth, Arthur

(b. Galashiels, Scotland, 10 October 1872; d. Manchester, England, 5 April 1941),

Chemistry.

Lapworth studied chemistry at Mason Science College (later the university), Birmingham, where his father was professor of geology. In 1893 he went to London as a research student at the City and Guilds College, working on naphthalene chemistry under H. E. Armstrong and collaborating with F. S. Kipping in studies on camphor. He, Kipping, and W. H. Perkin, Jr., became related by marrying three sisters. From 1895 to 1900 Lapworth was a demonstrator at the School of Pharmacy, then head of the chemistry department of Goldsmiths’ College. In 1909 he left London for Manchester, where he spent the rest of his life, first as senior lecturer in inorganic and physical chemistry, then (1913) as professor of organic chemistry, finally (1922) occupying the senior chair in the department. He was made a fellow of the Royal Society in 1910. The last years of Lapworth’s life, even before his retirement in 1935, were clouded by a long and painful illness. Until then he had been a man of many interests, including music, climbing, and what might broadly be called “natural history.” He was a reticent and modest person of nonconformist convictions, remembered by his students as friendly although rather remote.

As may be seen from his appointments, Lapworth’s knowledge was unusually wide. Although his name is not associated with any single great achievement, he did steady, meritorious work for nearly forty years. In his early work on camphor, he recognized an intramolecular change, related to the pinacolpinacolone rearrangement, which made possible acceptance of Bredt’s structure for camphor. A little later he began the study of reaction mechanisms, notably of cyanohydrin formation and the benzoin rearrangement, which entitles him to be regarded as one of the founders of modern “physical-organic chemistry.” He was one of the first to emphasize that organic compounds could ionize either actually or incipiently and that different parts of an organic molecule behave as though they bear electrical charges, either permanently or at the moment of reaction.

With the development of theories of valence based on the electronic structure of the atom, Lapworth was able to refine some speculations about “alternate polarities” into a classification of reactive centers as “anionoid” and “cationoid,” the charges being determined by the influence of a “key atom,” usually oxygen. In the mid-1920’s, when Lapworth elaborated on these concepts with his colleague Robert Robinson, a controversy ensued with C. K. Ingold and his school, who were developing a similar approach to the problems of organic reactivity using a different terminology (“nucleophilic” and “electrophilic” instead of anionoid and cationoid), which eventually gained general acceptance. The controversy, although occasionally sharp, was fruitful; and Lapworth’s last paper (1931) bore Ingold’s name as a coauthor.

BIBLIOGRAPHY

Lapworth worked by accumulation of detail rather than by publishing “important” papers, but special mention should be made of the following: “On the Constitution of Camphor,” in British Association Report for 1900, 299-327, which finally pointed the way out of the labyrinth of camphor chemistry; and his two papers on “alternate polarities” in Memoirs and Proceedings of the Manchester Literary and Philosophical Society,64 (1919-1920), no. 3, 16, and Journal of the Chemical Society,121 (1922), 416-427.

The most authoritative notice of Lapworth is Sir Robert Robinson, in Obituary Notices of Fellows of the Royal Society of London,5 (1945-1948), 555-572; repr. without portrait or bibliography, in Journal of the Chemical Society (1947), 989-996. See also G. N. Burkhardt, in Memoirs and Proceedings of the Manchester Literary and Philosophical Society,84 (1939-1941), vi-x; and Nature,147 (1941), 769.

W. V. Farrar