Glass flask, Erlenmeyer (conical), 500mL, ground glass opening, made by James A Jobling & Co Ltd., Wear Glass Works, Millfield, Sunderland, England, date 1922-1975. Object has, on the body, a circular trademark in white with "PYREX" at the top, "MADE IN ENGLAND" at the bottom and a white writing area in the middle. Below it is the capacity “500 ML”, also in white.

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.