Sir Patrick Manson GCMG FRS (3 October 1844 – 9 April 1922) was a Scottish physician who made important discoveries in parasitology, and was a founder of the field of tropical medicine.

Finally of age he formally graduated in October 1865, and was appointed Medical Officer at Durham Lunatic Asylum, where he worked for seven months.

Manson traveled to Formosa in 1866 as a medical officer to the Chinese Imperial Maritime Customs, where he started a long career in the research of tropical medicine.

His official daily duty involved inspecting ships docked at the port, check their crews and keep the meteorological record.

He also attended to Chinese patients in a local missionary hospital where he was exposed to a wide variety of tropical diseases for his postgraduate training without any supervision.

However, due to political conflict between China and Japan over the occupation of the island, he was advised by the British Consul to leave.

From this he began to work out the life cycle of filaria and through painstaking observation discovered that the worms were only present in the blood during the night and were absent during the day.

Placing this under the microscope, I was gratified to find that, so far from killing the Filaria, the digestive juices of the mosquito seemed to have stimulated it to fresh activity."

Manson observed that filaria only developed as far as an embryo within the human blood and that the mosquito must have a role in the life cycle.

His experimental results were published in the China Customs Medical Report in 1878, and relayed by Spencer Cobbold to the Linnean Society in London.

In the British Medical Journal in 1894 he published 'On the Nature and Significance of The Crescentic and Flagellated bodies in Malarial Blood'.

He then proposes, "the hypothesis I have ventured to formulate seems so well grounded that I for one, did circumstances permit, would approach its experimental demonstration with confidence.

The necessary experiments cannot for obvious reasons be carried out in England, but I would commend my hypothesis to the attention of medical men in India and elsewhere, where malarial patients and suctorial insects abound."

Manson's theory was finally proved by Ross in 1898 who described the full life cycle of the malarial parasite (of birds) inside the female mosquito.

The subsequent fall out between these two great men is well documented in the book The Beast in the Mosquito: The Correspondence of Ronald Ross and Patrick Manson.

In 1896, through his contacts at the Foreign Office, Manson managed to secure the release of Sun after he had been kidnapped in London by Chinese officials.

In a speech in 1897, he endorsed a call by fellow Scottish physician Andrew Davidson for courses in tropical medicine at every British medical school.

Sir Philip Manson-Bahr CMG DSO MD FRCP (Lond) (1881–1966) became a leader in the field of tropical medicine in his own right.