Detecting the Ghost

The scene that greets Watson on his return to Baker Street at the start of ‘The Naval Treaty’ (1893) captures the essence of the emerging detective story in the fin de siecle: Holmes was seated at his side-table clad in his dressing-gown and working hard over a chemical investigation. A large curved retort was boiling furiously in the bluish flame of a Bunsen burner, and the distilled drops were condensing into a two-litre measure...He dipped into this bottle or that, drawing out a few drops of each with his glass pipette, and finally brought a test-tube containing a solution over to the table. In his right hand he had a slip of litmus-paper. ‘You come at a crisis, Watson,’ said he. ‘If this paper remains blue, all is well. If it turns red, it means a man’s life.’ He dipped it into the test-tube, and it flushed at once into a dull dirty crimson. ‘Hum! I thought as much!’ he cried.1