Who invented the clinical thermometer?

Sir Thomas Clifford Allbutt (20 July 1836 – 22 February 1925) was an English physician best known for his role as commissioner for lunacy in England and Wales 1889-1892, president of the British Medical Association 1920, inventing the clinical thermometer, and supporting Sir William Osler in founding the History of Medicine Society.

Born in Dewsbury, he trained in London and Cambridge, and moved to Leeds, where he worked at the Leeds General Infirmary for twenty years. After the demands of hospital practice, Allbutt spent a brief period as a consultant to London asylums. He then took up the prestigious Regius Chair in Physic (medicine) at Cambridge, which he held until his death in 1925.

Between 1866 and 1867, he designed a medical thermometer that was much more portable, measuring only 6 inches long and taking only 5 minutes to record a patient's temperature. He made the design of his thermometer freely available to others, and it was quickly taken up by British physicians.

In 1612, the Italian inventor Santorio Santorio invented the mouth thermometer and perhaps the first crude clinical thermometer. However, it was both bulky, inaccurate, and took too long to get a reading. The mercury thermometer with a standardized scale, was invented by German physicist Daniel Gabriel Fahrenheit in 1714. By the mid 19th century, the medical thermometer was still a foot long (11.92 inches) and took as long as twenty minutes to take an accurate temperature reading.