# Dictionary of National Biography, 1912 supplement/Macfadyen, Allan

​MACFADYEN, ALLAN (1860–1907), bacteriologist, born on 26 May 1860 at Glasgow, was youngest of the four sons of Archibald Macfadyen, brass founder in Glasgow, by his wife Margaret, daughter of D. McKinlay of Stornaway. He was educated at Dr. Bryce's collegiate school at Edinburgh from 1871, and became a student in the university of Edinburgh in 1878, graduating M.B., C.M. (1883), M.D. with gold medal (1886), and B.Sc. in hygiene (1888). He studied chemistry and bacteriology in Berne, Göttingen, and Munich, and returning to England became a research scholar of the Grocers' Company (1889–1892), and lecturer on bacteriology at the College of State Medicine in London, which was subsequently amalgamated with the Jenner Institute of Preventive Medicine (afterwards called the Lister Institute), of which Macfadyen was made director in 1891. In 1903 Macfadyen was appointed secretary of the governing body as well as head of the bacteriological department. To him fell a very large share in planning and organising the present building of the Lister Institute on the Chelsea Embankment. He contracted typhoid fever in 1902 while engaged in investigating its bacillus. From 1901-4 he was Fullerian professor of physiology at the Royal Institution, where he delivered lectures on 'The Cell as the Unit of Life,' posthumously published in 1908. In 1905 he resigned his official position at the institute, and devoted himself entirely to original work, in the pursuit of which he accidentally infected himself with Malta fever and typhoid fever. He died at Hampstead a martyr to science on 1 March 1907 and was buried there.
Macfadyen's main bacteriological work was on the intracellular juices or endotoxins of certain bacteria. While some germs such as those which produce diphtheria and tetanus give off poisons as they grow, others, such as those responsible for cholera and typhoid fever, retain their poisons, which are therefore known as endotoxins. In order to obtain these endotoxins Macfadyen froze bacteria by means of Sir James Dewar's liquid air to a temperature of - 190° C, and then ground up the bacteria thus rendered brittle. He showed that by injecting small doses of these endotoxins into animals immunity from the disease could be established. In much of this work he was assisted by Mr. S. Rowland. Proofs of immunity had just been reached at the date of Macfadyen's death. He investigated, too, thermophilic bacteria, namely those which can live at a temperature of 140° C.; and with Sir James Dewar proved that the vital processes of some bacteria are not destroyed by a temperature of —250° C. or only 23 above that of absolute zero. His early work dealt largely with the fermentative action of bacteria.
​Besides the work mentioned, Macfadyen published many memoirs in medical and scientific periodicals, including the 'Journal of Anatomy and Physiology,' vols, xxi., xxv.-xxvi.; 'Proceedings of the Royal Society,' 1889; 'Transactions of the International Congress of Hygiene,' vol. ii.; 'Journal of Pathology and Bacteriology,' 1894.
He married on 7 Jan. 1890 Marie, daughter of Professor Cartling, director of the botanical gardens at Dettingen, but left no issue.
[Memoir by Prof. R. Tanner Hewlett, M.D., appended to The Cell as the Unit of Life, 1908 (with photograph and hst of published papers); Brit. Med. Journ. 1907, i. 601; information from his brother, Archibald Macfadyen.]
H. D. R.