Use the internet and find out the thermometers which were used in the past. On which principles where they based? What were their advantages and disadvantages? Why are they not used nowadays? Prepare a project report on the same.
Answers
The temperature of the human body has been used as a diagnostic sign since the earliest days of clinical medicine. The earliest thermal instruments were developed during the sixteenth and seventeenth centuries. In 1665, it was suggested that the melting point of ice and the boiling point of water should be the standard. The most common scales today are the Fahrenheit, Centigrade, and the Kelvin scales. Since the earliest days of medicine, physicians have recognized that the human body can exhibit an abnormal rise in temperature, usually defined as fever, as an obvious symptom of illnesses. In 1868, Wunderlich established that the temperature in a healthy person is constant and that variation of temperature occurs in disease. The Allbutt thermometer was the first practical device to become commercially available. The technology has then improved to provide highly accurate devices, for example, thermal imaging; its use is still growing in medicine.
The Thermometer
In 1654, Ferdinand II de’ Medici, Grand Duke of Tuscany, produced sealed tubes with a bulb and stem that were partly filled with alcohol. This was the first thermometer to depend on the expansion and contraction of a liquid, which was independent of barometric pressure. Many variants of this concept appeared, each unique as there was no standard scale. Christian Huygens in 1665 suggested using the melting point of ice and the boiling point of water as standards. The Danish astronomer Ole Rømer in Copenhagen used these upper and lower limits for a thermometer that he used to record the weather. There was still uncertainty about how well these parameters would work at different geographical latitudes. In 1694, Carlo Renaldini suggested that the ice and boiling water limits should be adopted as a universal scale. In England, Isaac Newton proposed in 1701 that a scale of 12 °C could be used between melting ice and body temperature!