British Drug Houses (BDH)
of 16-30 Graham Street, City Road, London, N1. Chemical Works: Wharf Road, London, N1. Telegraphic Address: "Tetradome, Telew, London". Telephone" 1622 Clerkenwell. (1922)
Ditto Addresses and Cables. Telephone: Clerkenwell 3000. (1929)
Ditto Address and Telephone: Cables: "Tetradome, London". Also Laboratory Chemicals Group of Poole, Dorset. (1947)
1908 Founded as a wholesaler for private chemists by amalgamation of various old established London firms of manufacturing chemists and wholesale druggists - Barron, Harveys and Co founded 1750, Hodgkinsons, Clarke and Ward founded in 1762, Hearon, Squire and Francis founded in 1714, Davy, Hill and Co, made up of A. S. Hill and Son founded in 1755 and Davy, Yates and Co founded in 1760.
1909 New works built in Graham St, London N1; these were sufficiently large to accommodate the existing businesses.
WWI: expansion into fine chemicals and laboratory chemicals which were no longer available from Germany, for which a factory was erected on the Wharf Rd site.
1922 British Industries Fair Advert as Manufacturers of Fine Chemicals and Pharmaceutical Products of the Highest Degree of Purity. (Stand Nos. A.12 and A.36) 
1926 New chemicals introduced were very pure ether for anaesthetic use and insulin.
1926 Incorporated as a public company.
1927 Launch of Radio-Malt, a mixture of vitamins A, B and D; the artificial production of vitamin D had been commercialised by BDH within a few weeks of the research results being released by the National Institute of Medical Research.
1929 Listed Exhibitor - British Industries Fair. Manufacturers of Fine Chemicals, Medicinal Chemicals, Laboratory Chemicals; Pure Chemicals for analysis and research; Microscopic Stains and Dyes. Pharmaceutical Products. (Stand Nos. K.80 and K.87) 
1944 Member of the Therapeutic Research Corporation of Great Britain which, together with ICI (Pharmaceuticals) and Kemball, Bishop and Co were working on the development and production of penicillin.
1946 Factory opened at Poole.
1947 British Industries Fair Advert for Laboratory and Fine Chemicals including Analar Reagents for Research and Analysis (Dorset) and Medical Products and Pharmaceutical Chemicals. Manufacturers of Medical Specialities including Liver Products, Insulin, Sex Hormones, Vitamins, Penicillin Preparations. (London). (Chemicals Section - Olympia, Ground Floor, Stand No. A.1087) 
1952 Acquired factory at Godalming
1961 Issued 35% of shares to Mead Johnson of USA, a pharmaceutical company, whose offer was preferred to that of a full merger with Warner-Lambert.
1962 Acquired James Woolley, Sons and Co, manufacturing and wholesale chemists, of Manchester. Its wholly owned subsidiary, J. C. Arnfield and Sons, was later amalgamated with Woolley's to trade as Woolley and Arnfield.
1964 Laboratory reagents and chemicals had become the main business. Divested the manufacturing and trading business. The name was changed to BDH group. The London wholesale business was transferred to a new subsidiary. The old name was used for the nutritionals business. Acquired wholesalers Hirst Brooke Goodalls of Leeds.
1967 Glaxo acquired Mead Johnson's shares in BDH and subsequently the remainder of the shares. The company was renamed BDH Chemicals; a new company BDH Pharmaceuticals was formed to market pharmaceutical products made by British Drug Houses and by Duncan Flockhart and Evans.
1973 Started development of nematic liquid crystals for electro-optic displays. BDH became one of the world's largest suppliers of liquid crystals, which were used in a variety of displays.
Name changed to BDH Ltd
1978 Merck acquired Baird and Tatlock, which included a host of British instrument and apparatus companies
1979 The University of Hull, the Ministry of Defence (RSRE) and BDH Chemical Co won The Queen's Award for Technological Achievement for the development of liquid crystals.
1987 The Baird and Tatlock companies were integrated with BDH Ltd.
1990 the UK company name was changed when all the businesses were consolidated as Merck Ltd. The BDH name is still retained as a brand name. 
2002 Name changed to Merck Chemicals Ltd
Sources of Information
-  The British Pharmaceutical Industry Since 1851
- The Times, 23 February 1926
- 1922 British Industries Fair Advert xxxviii; and p11
- The Times, 25 February 1926
- The Times, 8 March 1927
- The Times, Friday, Jan 27, 1928
- 1929 British Industries Fair p27
- The Times, 12 February 1944
- 1947 British Industries Fair Advert 3; and p41
- The Times, 26 May 1959
- The Times, 8 June 1959
- The Times, 10 March 1960
- The Times, 11 April 1962
- The Times, 28 May 1962
- The Times, 29 October 1962
- The Times, 27 May 1963
- The Times, 15 October 1963
- The Times, 14 August 1964
- The Times, 2 November, 1964
- The Times, 11 August 1965
- The Times, 27 October 1967
- The Times 30 March 1968
- The Times, 3 July 1968
- The Times, 22 September 1973
- New Scientist, 19 June 1986
-  Company History