Picture credit: http://www.museumoflondonprints.com/image/245686/sidney-paget-holmes-was-working-hard-over-a-chemical-investigation-c-1895
"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. My friend hardly glanced up as I entered, and I, seeing that his investigation must be of importance, seated myself in an armchair and waited. 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 held 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. "I will be at your service in an instant, Watson. You will find tobacco in the Persian slipper." He turned to his desk and scribbled off several telegrams, which were handed over to the page-boy. Then he threw himself down into the chair opposite and drew up his knees until his fingers clasped round his long, thin shins.
"A very commonplace little murder," said he. "You've got something better, I fancy. You are the stormy petrel of crime, Watson. What is it?""
- The Adventure of the Naval Treaty
And here is the modern day equivalent, from Sherlock:
Photo credit: aithine