How does Sherlock Holmes use deductive reasoning to learn about Mr. Wilson in The Red-Headed League by Arthur Conan Doyle?

In The Red-Headed League,Sherlock Holmes and John Watson are hired by Mr. Jabez Wilson to look into the mysterious disappearance of a business known as the Red-Headed League. Upon being visited by Mr. Wilson, Sherlock Holmes announces that he knows Mr. Wilson has worked as a manual laborer, uses snuff tobacco, is a Freemason, has been working at writing, and has spent time in China. How could he possibly know such things if he...

In The Red-Headed League, Sherlock Holmes and John Watson are hired by Mr. Jabez Wilson to look into the mysterious disappearance of a business known as the Red-Headed League. Upon being visited by Mr. Wilson, Sherlock Holmes announces that he knows Mr. Wilson has worked as a manual laborer, uses snuff tobacco, is a Freemason, has been working at writing, and has spent time in China. How could he possibly know such things if he is meeting Mr. Wilson for the first time? Mr. Holmes' career is built upon his talent for deductive reasoning-- the ability to observe his surroundings (including people) and make connections between the facts before him and the events which may have preceded.

For starters, Mr. Holmes has deduced by the fact that the muscles of Mr. Wilson's right hand are much larger than those in his left, that he has worked in manual labor. The exercise to his right hand resulted in greater muscle development. He has also discerned from the distinctive pin on Mr. Wilson's jacket that he is a member of the Freemasons. The "arc and compass," also called "Square and Compass," is a symbol used by the Freemasons. Mr. Holmes notices that the sleeve of Mr. Wilson's jacket has been worn down from writing and the repetitive motion of his wrist and elbow across the surface of a desk. Finally, Mr. Holmes recognizes a style of tattoo on Mr. Wilson which is unique to China. He does not tell us how he knows Mr. Wilson uses snuff tobacco, but if you are familiar with the other Sherlock Holmes stories, one can presume he noticed a staining on the fingers Mr. Wilson used to pinch out his tobacco. In each case, Mr. Holmes has observed the facts in front of him and worked out their most probable causes.