Vaccination: It means introduction of dead gems of another dis­ease in suspension called vaccine in the skin of a man. It is done generally by making few scratches with a knife on the arm and then rubbing the vaccine with it, e.g., BCG vaccine.

Inoculation: It means introduction of germ of the same diseases below the skin, so as to produce the disease in a mild form and thus give immunity from a severe attack of the same disease, e.g., plague, cholera. Q. What is meant by insulin?

A. It is a very useful drug for diabetes and was discovered by Dr. F.G. Banting in 1922. It is a product of unknown nature derived from the pancrease of animals. It regulates the percentage of sugar in blood. If the percentage is too high it converts the excess into starch and stores the starch in liver, muscles and skin. With the help of insulin a diabetic patient leads a normal healthy life. It is generally injected into the patient.