Taken from mobygames.com:

The famous detective Sherlock Holmes reads in a newspaper that the Tower of London has been closed for “reasons of security”. Shortly afterwards he finds out that the Crown Jewels belonging to the royal family were stolen. The fact is kept in secret, and Dr. Watson, Sherlock Holmes best friend and associate, must retrieve them within forty-eight hours to avert a world-wide scandal. In this text adventure the player controls Dr. Watson, exploring familiar locations in London, questioning suspects and solving puzzles. The interaction with the game world is performed by typing combinations of verbs and objects. Descriptions of locations must be read carefully, as they may contain clues vital to solving the game.

http://www.mobygames.com/game/dos/sherlock-the-riddle-of-the-crown-jewels