13186    'If this paper remains blue, all is well.

13187    If it turns red, it means a man's life.'

13188    He dipped it into the test-tube, and it flushed at once into a dull, dirty crimson.

13189    'Hum!

13190    I thought as much!' he cried.

13191    'I shall be at your service in one instant, Watson.

13192    You will find tobacco in the Persian slipper.'

13193    He turned to his desk and scribbled off several telegrams, which were handed over to the page-boy.

13194    Then he threw himself down in the chair opposite, and drew up his knees until his fingers clasped round his long, thin shins.

13195    'A very commonplace little murder,' said he.

13196    'You've got something better, I fancy.

13197    You are the stormy petrel of crime, Watson.

13198    What is it?'

13199    I handed him the letter, which he read with the most concentrated attention.

13200    'It does not tell us very much, does it?' he remarked, as he handed it back to me.