Dr. Watson's appearance was likely inspired by Arthur Conan Doyle, the author who created the character. Doyle may have also drawn on aspects of his own physical appearance when describing Watson in the Sherlock Holmes stories.
Yes, twice, just like Watson, the first died of a severe sickness
The obvious answer would be that it was Arthur Conan Doyle himself. Doyle watched Doctor Bell as he used his powers of observation. Later he recorded this sort of thing by putting himself in the role of Dr. Watson as he wrote the Sherlock Holmes stories.
Conan Doyle liked spiritualism
Conan Doyle never says
Poe's detective stories, particularly those featuring C. Auguste Dupin, laid the foundation for the detective genre. Sir Arthur Conan Doyle's famous character, Sherlock Holmes, was inspired by Dupin, and Doyle even acknowledged Poe's influence on his work. Doyle's Sherlock Holmes stories expanded on Poe's detective fiction, popularizing the genre further.
Agatha Christie is a similar author to Sir Arthur Conan Doyle. Both authors are known for their classic detective fiction, with Christie's most famous detective being Hercule Poirot and Miss Marple. Like Doyle, Christie's works feature intricate plots, unexpected twists, and memorable characters.
Arthur Conan Doyle was inspired by one of his old masters in university. He was called Joseph Bell. Doyle admired Bell immensely for his cool attitude, razor-sharp mind and brilliant powers of deduction. Bell becamse Holmes, and Doyle became Watson. But Holmes' attire was based on someone else, the illustrator's younger brother.
The man himself? NO He was imagined and created in fiction by Sir Arthur Conan Doyle, a doctor and (to make ends meet) writer. Doyle learned to medically examine patients and observe them from Dr. Joseph Bell, who did some observations on his patients like Holmes. Many agree (as Doyle said himself) that Bell was the inspiration to Doyle to create Holmes.
He didn't like to have to wait for patients
If you meant what kind of nose did he have, hawk-like is the description given by Conan Doyle
WARNING - CONTAINS SPOILERS!!! They fall over the Reichenbach Falls and (supposedly) die, although, Sherlock comes back three years later -- and says that he never fell in the first place -- in order to clear his name after the version written by Moriarty's brother (also named James) was published, and he is able to carry on his work. told ya... spoilers.
Charles Altamont Doyle (1832-1893) was an artist just like three of his brothers and father though he was not as successful as them. He suffered from depression and alcoholism, and he was put in a nursing home in 1881. Even though he continued to draw, he was moved to several other increasingly secure institutions until his death eleven years later.