Introduction:
The word "virus" is derived from the Latin word "virus", which means poison or venom. The term "virus" was first used to describe a disease-causing agent in the late 19th century.

Who gave the name virus?
The name "virus" was given by a Dutch microbiologist named Martinus Beijerinck in 1898. Beijerinck was studying the tobacco mosaic disease, which was causing significant damage to tobacco crops in the Netherlands at the time. He discovered that the disease was caused by a pathogen that was smaller than bacteria and could not be seen under a microscope.

Beijerinck's contribution:
Beijerinck's work on the tobacco mosaic virus was groundbreaking. He was the first to demonstrate that viruses were distinct from bacteria and other microorganisms. Beijerinck also discovered that viruses could only replicate inside a host cell, a concept that is now known as the "obligate intracellular parasite" theory.

Importance of Beijerinck's work:
Beijerinck's work laid the foundation for the field of virology, which is the study of viruses and viral diseases. His discoveries led to the development of vaccines and treatments for many viral infections, including smallpox, polio, and influenza.

Conclusion:
In conclusion, the term "virus" was first used by Martinus Beijerinck in 1898 to describe a disease-causing agent that was smaller than bacteria and could not be seen under a microscope. Beijerinck's work on the tobacco mosaic virus was groundbreaking and laid the foundation for the field of virology.

The name virus means venum was given by Pasteur(ncert page-26)