English bacteriologist, the original discoverer in 1915 of bacteriophages (often called phages), the relatively large viruses that attack and destroy bacteria. He also researched into Johne's disease, a chronic intestinal infection of cattle.Twort was born in Camberley, Surrey, and studied medicine at St Thomas's Hospital, London. From 1909 he was superintendent of the Brown Institute, a pathology research centre, and he was also professor of bacteriology at the University of London from 1919.

While working with cultures of Staphylococcus aureus (the bacterium that causes the common boil), Twort noticed that colonies of these bacteria were being destroyed. He isolated the substance that produced this effect and found that it was transmitted indefinitely to subsequent generations of the bacterium. He then suggested that the substance was a virus. Twort was unable to continue this work, and the importance of bacteriophages was not recognized until the 1950s.

Twort also discovered that vitamin K is needed by growing leprosy bacteria, which opened a new field of research into the nutritional requirements of microorganisms.

Victor Horsley was born in Kensington, London, and educated at Cranbrook School in Kent and at University College London, where he studied medicine under John Burdon Sanderson and G D Thane. In 1880 he was appointed House Surgeon at University College Hospital where he experimented with anaesthetics. Horsley studied at postgraduate level in Berlin in 1881 and in 1882 was appointed Surgical Registrar at University College Hospital. From 1884 to 1890 Horsley was Professor-Superintendent of the Brown Institute, where he did experiments on localization of brain function (with Charles Beevor), on the pituitary gland, on the relation of the larynx to the nervous system (with Felix Semon), and on the thyroid gland, myxoedema and cachexia strumipriva. In 1885 he was promoted to assistant surgeon. In 1886 he took the position of Assistant Professor of Surgery at the National Hospital for Paralysis and Epilepsy, Queen Square, where he performed operations on the brain and spinal cord. In 1886 he was appointed secretary of the Local Government Board Commission on Hydrophobia, and also studied Pasteur's anti-rabies vaccine. In the same year he was elected Fellow of the Royal Society. From 1887 to 1896 Horsley was Professor of Pathology at University College London. He married Eldred, daughter of Sir Frederick Bramwell, in 1887, and the couple had two sons and one daughter. Horsley was elected President of the Medical Defence Union in 1893 and the British Medical Temperance Association in 1896. In 1897 he was appointed to the Senate of the University of London and elected to the General Medical Council. From 1899 to 1902 he was Professor of Clinical Surgery at University College London. In 1902 he was knighted for his work in medicine. In 1907 he published Alcohol and the Human Body with Dr Mary Sturge. Towards the end of his life he stood as a Liberal candidate in London but later resigned; he was also rejected by Leicester. In 1915 and 1916 he travelled extensively in a medical capacity, performing surgery on the war field. He died at Amara from heatstroke and pyrexia in July 1916. Lady Horsley continued to be involved in radical causes after her husband's death. Their sons, Siward and Oswald, were both educated at Bedales School in Hampshire, then at Oxford University. Both fought in the Great War, the younger, Oswald, being killed in a flying accident at the end of 1918. The elder, Siward, died in 1920. In 1917 Victor's daughter Pamela married Stanley Robinson, who was knighted in 1972 for his work in the British Museum. Pamela and her husband helped to found a Babies Club in Chelsea

John Scott Burdon-Sanderson was born in December 1828 and educated at home. He went to the University of Edinburgh to study medicine in 1847 and graduated MD in 1851 with a gold medal for his thesis. He then went to continue his studies in Paris. In 1853 he settled in London as a practising physician and was soon appointed Medical Registrar of St Mary's Hospital in Paddington. That same year he married Ghetal, eldest daughter of the Rev. Ridley Haim Herschell. In 1854 he served the medical school at St Mary's Hospital as a Lecturer, first in botany and then in medical jurisprudence. In 1856 he was appointed Medical Officer of Health for Paddington and during the eleven years of his tenure of the post, gave proof of his eminence. He greatly improved sanitary conditions of the district and in 1860 he was made an inspector under the Privy Council. Also in 1860, Burdon-Sanderson became a physician at the Brompton Hospital for Consumption and also at the Middlesex Hospital. He continued carrying out investigations. In 1867 he was elected fellow of the Royal Society and Croonian lecturer. In 1870 he gave up his hospital appointments and private practice in order to devote himself exclusively to scientific research. In 1871 he was appointed Professor Superintendent of the Brown Institution (University of London) and as Professor of Practical Physiology and Histology at University College London. In 1874 he became Jodrell Professor of Physiology at University College London. He became FRCP in 1871, was Harveian orator at the College of Physicians in 1878, and was awarded the Baly medal in 1880. In 1882 he was invited to Oxford as first Waynflete Professor of Physiology. The degree of MA was conferred on him in 1883 and that of DM in 1895. He remained Waynflete Professor until 1895, when he was appointed Regius Professor of Medicine in the University. He resigned the Regius Professorship in 1903. Burdon-Sanderson served on important commissions and many honours were given to him. He took part in the modern advance in pathology, and in physiology he was an acknowledged master. He wrote many papers in his lifetime. In August 1899 he was created a baronet. He died at Oxford in November 1905

British physiologist, who was awarded the 1932 Nobel Prize for Physiology or Medicine for his fundamental contributions to the understanding of the functions of the central nervous system. Born in London, Sherrington obtained his degree in medicine from the University of Cambridge in 1885. He also studied under the German scientists Rudolf Virchow and Robert Koch. From early studies of the nervous systems and reflexes of higher mammals, he proved that the stimulation of one set of muscles causes the simultaneous inhibition of the opposing set of muscles. He later established the three major groupings of sensory organs: the exteroreceptors, such as the eyes; the interoceptors, such as the taste buds; and the proprioceptors, which lie deep within the organism. Sherrington was also the originator of such terms and concepts as synapse and neuron. He was knighted in 1922.