Glass flask, 200ml Kohlrausch volumetric flask, the object is inscribed on the main body with "B", the Baird and Tatlock trademark, "2919 /44" and "200ml", and on the wide neck with "1", the object bears a circular yellow sticker marked "MC 61", made by Baird and Tatlock, place and date of manufacture unknown.

This piece of chemical glassware, part of a collection of just over 200 items, came from the laboratory of Thomas McLachlan and Partners, which was based at 4 Hanway Place, London, until 1973. McLachlan and Partners were public analysts and food technologists.

In Thomas McLachlan’s time, the principal task of the Public Analyst was to ensure the safety and correct description of food by testing for compliance with legislation. McLachlan was appointed as Public Analyst for many regions including Fulham, Chelsea and St Marylebone in London and also for other regions neighbouring London, including Thurrock and Reading. Most Public Analysts like McLachlan were also Agricultural Analysts carrying out similar work on animal feedstuffs and fertilisers. They also tested drinking water and other consumer products. McLachlan was also involved in pioneering environmental work in air and water pollution.