Page 281 - New Medley 5 Semester 2

Clinical Thermometer

Sometimes our body becomes warm. It is called fever. In ancient times,

some experts could measure it by touching the body and by feeling the
pulse. It does not give a correct idea. Today, the clinical thermometer

can measure it exactly. It was developed by G.D. Fahrenheit in ad 1715.

There are two types of thermometers. One gives the temperature in

Fahrenheit or °F, and the other in Celsius or °C. The normal temperature
of human body is 98.4°F or 37°C. If the temperature of the body rises,
then it is fever. Today, digital thermometers are also used for measuring

the body temperature.

Stethoscope

We can check the functioning of the lungs and the heart
with the help of a stethoscope. It was invented by a

French doctor Rene Laennec in ad 1816. Once Dr Rene
saw two children playing on the roadside. They were

sitting on the ends of a long and hollow log of wood.
They were whispering through the long and hollow log

of wood.

Dr Rene asked them what they were doing. The children Dr Rene Laennec
told him that they were talking to each other. They could hear even the

slightest sound from one end of log to the other. Dr Rene checked it

and then tried it on a patient. He rolled a newspaper and placed its one
end on the chest of a patient and the other in his ear. He was surprised
to hear the heart beat of the patient.

This experiment led to the development of the stethoscope. Many
modifications have been done to improve its working. Nowadays, every

doctor in the world uses a stethoscope. We can generally see it hanging
around the neck of the doctor.

Microscope

A microscope can enlarge a small thing many times. The first microscope
was probably made by Zacharias Janssen in 1590. He was the owner

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