Born 26 August 1867 at Repps, Norfolk, the elder son and second child, a sister having died in infancy, of Henry Lack, a gentleman-farmer, and Emily Martha Case, his wife. H L Lack's uncle Thomas Lambert Lack, MRCS 1869, was for many years a well-known practitioner at Hingham near Attleboro' in Norfolk. He was educated at a private school in Norwich, at King's College, London, and at King's College Hospital, which he entered shortly before Lister retired from the active staff. He served as demonstrator of surgery and as house surgeon and pathological assistant to Sir W Watson Cheyne. He then served as resident medical officer at the Children's Hospital, Paddington Green, and at the Throat Hospital in Golden Square, having decided to specialize as a laryngologist. In 1893 he took the Fellowship and in 1894 the London doctorate, and was subsequently elected to the staff of each of these two hospitals, becoming surgeon to the ear and throat department of the Children's Hospital and, ultimately, consulting surgeon to the Throat Hospital. But his closest connexion was with the London Hospital, where he served as aural surgeon and became consulting aural surgeon on retirement. In 1899 Lack won the Jacksonian prize with his essay on "The pathology, diagnosis, and treatment of inflammatory affections of the nasal fossae and the associated sinuses and air-cells". The essay formed the basis of his book *Diseases of the nose and accessory sinuses*, dedicated to his old teacher Watson Cheyne and published in 1906. This book made Lack's name, and he kept himself in the front rank of his specialty till he retired. It was not only the first exhaustive work on the subject in English, but was based very largely on the rich original material of his own clinical observations and pathological researches. For he was not only an excellent clinician with brilliant diagnostic ability and a kind and considerate manner but also had the intellectual qualities of a natural master of research, a critical and observant eye, and a wide knowledge of pathology. He made a considerable study of nasal obstruction and in particular of nasal polypi and their origin, and devised an operation for their removal which necessitated a partial eradication of the ethmoid cells. He also studied congenital laryngeal stridor, and the bacteriology of fibrinous rhinitis and its relation to diphtheria. He also devised an operation for cancer of the vocal cord, which involved the removal of a part of the thyroid cartilage. He was a skilled operator, with a natural tendency to conservatism; but he could be radical when necessary, and some of his elaborate operations proved less successful in other hands. He was the first to employ in England Nagelschmidt's 1910 treatment of malignant growths by diathermy. He served as secretary of the section of laryngology of the British Medical Association at the Ipswich meeting in 1900, was a vice-president at Oxford in 1904, and president of the section at Aberdeen in 1914. Lack was a keen cyclist and played a good game of golf, especially while he had a week-end house at Littlestone. He retired completely at the age of sixty, and devoted himself to country life, gardening, and watching birds in Norfolk. He had practised and continued to live at 71 Marlborough Place, NW, with a country house at Warninglid, Sussex. He was a cultivated and artistic man and collected fine furniture. With Mrs Lack he organized a poetry-reading society which met at their house. He married in 1909 Kathleen, daughter of Colonel McNeill Rhind, who survived him with three sons and a daughter. His eldest son became an authority on wild birds, and another son Captain Christopher Cheyne Lack, MRCS, was serving in the RAMC at the time of Lack's death. He died in London on 14 February 1943, aged 75. Publications: Operative treatment of malignant diseases of larynx. *Lancet*, 1896, 1, 1638. Congenital laryngeal obstruction. *Ibid*. 1897, 2, 653. *The diseases of the nose and its accessory sinuses*. London, 1906. Tuberculosis of the larynx. *Clin J* 1914, 43, 678. Partial resection or window resection of the larynx for intrinsic malignant disease. *J Laryng* 1916, 31, 121. An improved operation for malignant diseases of the larynx. *Lancet*, 1916, 2, 827.