The Science of Deduction
Sherlock Holmes took his bottle from the corner of the mantelpiece，and his hypodermic syringe from its neat morocco case.
With his long， white， nervous fingers he adjusted the delicateneedle and rolled back his left shirtcuff. For some little time hiseyes rested thoughtfully upon the sinewy forearm and wrist， alldotted and scarred with innumerable puncture-marks. Finallyhe thrust the sharp point home， pressed down the tiny piston，and sank back into the velvet-lined armchair with a long sigh ofsatisfaction.
Three times a day for many months I had witnessed thisperformance， but custom had not reconciled my mind to it. Onthe contrary， from day to day I had become more irritable at thesight， and my conscience swelled nightly within me at the thoughtthat I had lacked the courage to protest. Again and again I hadregistered a vow that I should deliver my soul upon the subject；but there was that in the cool， nonchalant air of my companionwhich made him the last man with whom one would care totake anything approaching to a liberty. His great powers， hismasterly manner， and the experience which I had had of his manyextraordinary qualities， all made me diffident and backward incrossing him.
Yet upon that afternoon， whether it was the Beaune which Ihad taken with my lunch or the additional exasperation producedby the extreme deliberation of his manner， I suddenly felt that Icould hold out no longer.
“Which is it to-day？” I asked， “morphine or cocaine？”
He raised his eyes languidly from the old black-letter volumewhich he had opened.
“It is cocaine，” he said， “a seven-per-cent. solution. Would youcare to try it？”
“No， indeed，” I answered brusquely. “My constitution has notgot over the Afghan campaign yet. I cannot afford to throw anyextra strain upon it.”
He smiled at my vehemence. “Perhaps you are right， Watson，”
he said. “I suppose that its influence is physically a bad one. I findit， however， so transcendently stimulating and clarifying to themind that its secondary action is a matter of small moment.”
“But consider！” I said earnestly. “Count the cost！ Your brainmay， as you say， be roused and excited， but it is a pathologicaland morbid process which involves increased tissue-change andmay at last leave a permanent weakness. You know， too， what ablack reaction comes upon you. Surely the game is hardly worththe candle. Why should you， for a mere passing pleasure， risk theloss of those great powers with which you have been endowed？
Remember that I speak not only as one comrade to another but asa medical man to one for whose constitution he is to some extentanswerable.”
He did not seem offended. On the contrary， he put his fingertipstogether， and leaned his elbows on the arms of his chair， likeone who has a relish for conversation.
“My mind，” he said， “rebels at stagnation. Give me problems，give me work， give me the most abstruse cryptogram， or themost intricate analysis， and I am in my own proper atmosphere. Ican dispense then with artificial stimulants. But I abhor the dullroutine of existence. I crave for mental exaltation. That is why Ihave chosen my own particular profession， or rather created it， forI am the only one in the world.”
“The only unofficial detective？” I said， raising my eyebrows.
“The only unofficial consulting detective，” he answered. “I amthe last and highest court of appeal in detection. When Gregson，or Lestrade， or Athelney Jones are out of their depths—which，by the way， is their normal state—the matter is laid before me. Iexamine the data， as an expert， and pronounce a specialist’s opinion.
I claim no credit in such cases. My name figures in no newspaper.
The work itself， the pleasure of finding a field for my peculiarpowers， is my highest reward. But you have yourself had someexperience of my methods of work in the Jefferson Hope case.”
“Yes， indeed，” said I cordially. “I was never so struck by anythingin my life. I even embodied it in a small brochure， with thesomewhat fantastic title of ‘A Study in Scarlet.’ ”
He shook his head sadly.
“I glanced over it，” said he. “Honestly， I cannot congratulate youupon it. Detection is， or ought to be， an exact science and shouldbe treated in the same cold and unemotional manner. You haveattempted to tinge it with romanticism， which produces much thesame effect as if you worked a love-story or an elopement into thefifth proposition of Euclid.”
“But the romance was there，” I remonstrated. “I could nottamper with the facts.”
“Some facts should be suppressed， or at least， a just sense ofproportion should be observed in treating them. The only point inthe case which deserved mention was the curious analytical reasoningfrom effects to causes by which I succeeded in unraveling it.”
I was annoyed at this criticism of a work which had beenspecially designed to please him. I confess， too， that I was irritatedby the egotism which seemed to demand that every line of mypamphlet should be devoted to his own special doings. More thanonce during the years that I had lived with him in Baker Street Ihad observed that a small vanity underlay my companion’s quietand didactic manner. I made no remark， however， but sat nursingmy wounded leg. I had had a Jezail bullet through it some timebefore， and though it did not prevent me from walking it achedwearily at every change of the weather.
“My practice has extended recently to the Continent，” saidHolmes after a while， filling up his old brier-root pipe. “I wasconsulted last week by Francois Le Villard， who， as you probablyknow， has come rather to the front lately in the French detectiveservice. He has all the Celtic power of quick intuition， but he isdeficient in the wide range of exact knowledge which is essential tothe higher developments of his art. The case was concerned with awill and possessed some features of interest. I was able to refer himto two parallel cases， the one at Riga in 1857， and the other at St.