Glass lactometer, England, 1875-1900
Milk inspection became a government responsibility in the late 1800s. This mercury filled glass lactometer would have been placed into a cup of milk. If the milk was pure, the lactometer would float level with the ‘“M” marked on the scale. Other points on the scale indicated the degree to which the milk had been diluted with water. For example, if the lactometer floated at “3” on the scale, the milk contained 25 per cent water; at ‘“2” it was 50 per cent. Inspection was important to ensure customers were getting what they paid for. The Sale of Food and Drugs Act, 1875, stated that it was illegal to sell products that did not meet customer expectations.
Related Themes and Topics
A hydrometer is an instrument used to measure the specific gravity (or relative density) of liquids; that is, the ratio of the density of the liquid to the density of water. A hydrometer is usually cylindrical and made from glass.
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A type of hydrometer for measuring lactose sugars in milk.