What had Henry lost at the hotel in Hound of Baskervilles?

In the story "The Hound of Baskervilles" by Sir Arthur Conan Doyle, Henry Baskerville does not lose anything at a hotel. He is a victim of a murder.

The character who loses something at a hotel is Sir Charles Baskerville, Henry's uncle. Sir Charles lost his watch at the hotel in the first chapter of the story. This detail becomes important later when Sherlock Holmes uses the watch to connect the dots and identify the real murderer.