Before the invention of the thermometer, the Western doctors to see a doctor, also like now, you need to understand the patient's heat".
But because there is no special temperature measurement instrument, they can only use their own hands to contact the patient's body to make a judgment. The feeling of the hand is not reliable, but it is not accurate. Therefore, how to measure the body temperature becomes a difficult problem to be solved by doctors.
The first thermometer was developed on the basis of the thermometer. The first thermometer was invented by Galileo in 1593, and it was only 300 years later that it was designed to use a convenient and reliable thermometer.
The thermometer of Galileo invented by the use of the physical knowledge of the expansion of the gas. Later, scientists and according to the phenomenon of liquid heating, the invention of the mercury thermometer and other kinds of thermometer.
The real body temperature measurement for clinical diagnosis, is in 1858 the German doctor Feng Deli, he let the patient with the mouth containing mercury thermometer, from time to time to see the temperature of the above. He did not dare to ask the patient to take out the thermometer, because he took it out, and a cold air, the temperature dropped down.
In 1866, the British doctor Albert came up with a good idea: in the thermometer of the mercury tube made a narrow way. So, put the thermometer in your mouth, the mercury rises, remove thermometer, mercury column does not fall, but in a narrow road there is disconnected, narrow road, above always maintain body temperature readings. Thus, the birth of a medical thermometer. Since then the 100 years of the temperature gauge has not changed much.