Potain sphygmomanometer, in case, which belonged to T. Lauder Brenton. Made by Charles Verdin and G. Boulitte Sr, 7 rue Linne, Paris, France, 1898-1910.

A sphygmomanometer measures blood pressure. This example is of a type designed by Charles Potain (1925-1907). It has an aneroid barometer dial showing changes in blood pressure. Modern examples have an inflatable cuff and graduated U tube. Maximum blood pressure is taken using a pelotte, or bulb. This was pressed onto the radial artery in the arm until the pulse disappeared. Potain’s sphygmomanometer differs from earlier examples in that the pelotte contains air, not water. This example belonged to British physician Sir Thomas Lauder Brunton (1844-1916).