Sherlock Holmes took his bottle from the corner of the mantel-piece, 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. Finally, hethrust the sharp point home, pressed down the tiny piston, andsank 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 to takeanything approaching to a liberty. His great powers, his masterlymanner, and the experience which I had had of his many extraor-dinary qualities, all made me diffident and backward in crossinghim.

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. Wouldyou care to try it?"

"No, indeed," I answered brusquely. "My constitution hasnot got over the Afghan campaign yet. I cannot afford to throwany extra strain upon it."

He smiled at my vehemence. "Perhaps you are right, Wat-son," he said. "I suppose that its influence is physically a badone. I find it, however, so transcendently stimulating and clarify-ing to the mind that its secondary action is a matter of smallmoment."

"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 least leave a permanent weakness. You know, too, whata black reaction comes upon you. Surely the game is hardlyworth the candle. Why should you, for a mere passing pleasure,risk the loss of those great powers with which you have beenendowed? Remember that I speak not only as one comrade toanother but as a medical man to one for whose constitution he isto some extent answerable."

He did not seem offended. On the contrary, he put his finger-tips together, 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 prob-lems, give me work, give me the most abstruse cryptogram, orthe most intricate analysis, and I am in my own proper atmo-sphere. I can dispense then with artificial stimulants. But I abhorthe dull routine of existence. I crave for mental exaltation. Thatis why I have chosen my own particular profession, or rathercreated it, for I am the only one in the world."

"The only unofficial detective?" I said, raising my eyebrows.

"The only unofficial consulting detective," he answered. "Iam the last and highest court of appeal in detection. When Greg-son, or Lestrade, or Athelney Jones are out of their depths --which, by the way, is their normal state -- the matter is laidbefore me. I examine the data, as an expert, and pronounce aspecialist's opinion. I claim no credit in such cases. My namefigures in no newspaper. The work itself, the pleasure of findinga field for my peculiar powers, is my highest reward. But youhave yourself had some experience of my methods of work in theJefferson Hope case."

"Yes, indeed," said I cordially. "I was never so struck byanything in my life. I even embodied it in a small brochure, withthe somewhat fantastic title of 'A Study in Scarlet.' "

He shook his head sadly.

"I glanced over it," said he. "Honestly, I cannot congratulateyou upon it. Detection is, or ought to be, an exact science andshould be treated in the same cold and unemotional manner. Youhave attempted to tinge it with romanticism, which producesmuch the same effect as if you worked a love-story or anelopement into the fifth 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 pointin the case which deserved mention was the curious analyticalreasoning from effects to causes, by which I succeeded in unrav-elling it."

I was annoyed at this criticism of a work which had beenspecially designed to please him. I confess, too, that I wasirritated by the egotism which seemed to demand that every lineof my pamphlet should be devoted to his own special doings.More than once during the years that I had lived with him inBaker Street I had observed that a small vanity underlay mycompanion's quiet and didactic manner. I made no remarkhowever, but sat nursing my wounded leg. I had had a Jezaiibullet through it some time before, and though it did not preventme from walking it ached wearily 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 youprobably know, has come rather to the front lately in the Frenchdetective service. He has all the Celtic power of quick intuitionbut he is deficient in the wide range of exact knowledge which isessential to the higher developments of his art. The case wasconcerned with a will and possessed some features of interest. Iwas able to refer him to two parallel cases, the one at Riga in1857, and the other at St. Louis in 1871, which have suggestedto him the true solution. Here is the letter which I had thismorning acknowledging my assistance."

He tossed over, as he spoke, a crumpled sheet of foreignnotepaper. I glanced my eyes down it, catching a profusion ofnotes of admiration, with stray magnifiques, coup-de-maitres andtours-de-force, all testifying to the ardent admiration of theFrenchman.

"He speaks as a pupil to his master," said I.

"Oh, he rates my assistance too highly," said Sherlock Holmeslightly. "He has coosiderable gifts himself. He possesses twoout of the three qualities necessary for the ideal detective. He hasthe power of observation and that of deduction. He is onlywanting in knowledge, and that may come in time. He is nowtranslating my small works into French."

"Your works?"

"Oh, didn't you know?" he cried, laughing. "Yes, I havebeen guilty of several monographs. They are all upon technicalsubjects. Here, for example, is one 'Upon the Distinction be-tween the Ashes of the Various Tobaccos.' In it I enumerate ahundred and forty forms of cigar, cigarette, and pipe tobacco,with coloured plates illustrating the difference in the ash. It is apoint which is continually turning up in criminal trials, andwhich is sometimes of supreme importance as a clue. If you cansay definitely, for example, that some murder had been done bya man who was smoking an Indian lunkah, it obviously narrowsyour field of search. To the trained eye there is as much differ-ence between the black ash of a Trichinopoly and the white fluffof bird's-eye as there is between a cabbage and a potato."

"You have an extraordinary genius for minutiae," I remarked.

"I appreciate their importance. Here is my monograph uponthe tracing of footsteps, with some remarks upon the uses ofplaster of Paris as a preserver of impresses. Here, too, is acurious little work upon the influence of a trade upon the form ofthe hand, with lithotypes of the hands of slaters, sailors, cork-cutters, compositors, weavers, and diamond-polishers. That is amatter of great practical interest to the scientific detective -- especially in cases of unclaimed bodies, or in discovering theantecedents of criminals. But I weary you with my hobby."

"Not at all," I answered earnestly. "It is of the greatestinterest to me, especially since I have had the opportunity ofobserving your practical application of it. But you spoke justnow of observation and deduction. Surely the one to some extentimplies the other."

"Why, hardly," he answered, leaning back luxuriously in hisarmchair and sending up thick blue wreaths from his pipe. "Forexample, observation shows me that you have been to the WigmoreStreet Post-Office this morning, but deduction lets me know thatwhen there you dispatched a telegram."

"Right!" said I. "Right on both points! But I confess that Idon't see how you arrived at it. It was a sudden impulse uponmy part, and I have mentioned it to no one."

"It is simplicity itself," he remarked, chuckling at mysurprise -- "so absurdly simple that an explanation is superfluous;and yet it may serve to define the limits of observation and ofdeduction. Observation tells me that you have a little reddishmould adhering to your instep. Just opposite the Wigmore StreetOffice they have taken up the pavement and thrown up someearth, which lies in such a way that it is difficult to avoidtreading in it in entering. The earth is of this peculiar reddish tintwhich is found, as far as I know, nowhere else in the neigh-bourhood. So much is observation. The rest is deduction."

"How, then, did you deduce the telegram?"

"Why, of course I knew that you had not written a letter,since I sat opposite to you all morning. I see also in your opendesk there that you have a sheet of stamps and a thick bundle ofpostcards. What could you go into the post-office for, then, butto send a wire? Eliminate all other factors, and the one whichremains must be the truth."

"In this case it certainly is so," I replied after a little thought."The thing, however, is, as you say, of the simplest. Would youthink me impertinent if I were to put your theories to a moresevere test?"

"On the contrary," he answered, "it would prevent me fromtaking a second dose of cocaine. I should be delighted to lookinto any problem which you might submit to me."

"I have heard you say it is difficult for a man to have anyobject in daily use without leaving the impress of his individual-ity upon it in such a way that a trained observer might read it.Now, I have here a watch which has recently come into mypossession. Would you have the kindness to let me have an opinionupon the character or habits of the late owner?"

I handed him over the watch with some slight feeling ofamusement in my heart, for the test was, as I thought, animpossible one, and I intended it as a lesson against the some-what dogmatic tone which he occasionally assumed. He balancedthe watch in his hand, gazed hard at the dial, opened the back,and examined the works, first with his naked eyes and then witha powerful convex lens. I could hardly keep from smiling at hiscrestfallen face when he finally snapped the case to and handed itback.

"There are hardly any data," he remarked. "The watch hasbeen recently cleaned, which robs me of my most suggestivefacts. "

"You are right," I answered. "It was cleaned before beingsent to me."

In my heart I accused my companion of putting forward amost lame and impotent excuse to cover his failure. What datacould he expect from an uncleaned watch?

"Though unsatisfactory, my research has not been entirelybarren," he observed, staring up at the ceiling with dreamy,lack-lustre eyes. "Subject to your correction, I should judge thatthe watch belonged to your elder brother, who inherited it fromyour father."

"That you gather, no doubt, from the H. W. upon the back?"

"Quite so. The W. suggests your own name. The date of thewatch is nearly fifty years back, and the initials are as old as thewatch: so it was made for the last generation. Jewellery usuallydescends to the eldest son, and he is most likely to have the samename as the father. Your father has, if I remember right, beendead many years. It has, therefore, been in the hands of youreldest brother."

"Right, so far," said I. "Anything else?"

"He was a man of untidy habits -- very untidy and careless.He was left with good prospects, but he threw away his chances,lived for some time in poverty with occasional short intervals ofprosperity, and finally, taking to drink, he died. That is all I cangather."

I sprang from my chair and limped impatiently about the roomwith considerable bitterness in my heart.

"This is unworthy of you, Holmes," I said. "I could not havebelieved that you would have descended to this. You have madeinquiries into the history of my unhappy brother, and you nowpretend to deduce this knowledge in some fanciful way. Youcannot expect me to believe that you have read all this from hisold watch! It is unkind and, to speak plainly, has a touch ofcharlatanism in it."

"My dear doctor," said he kindly, "pray accept my apolo-gies. Viewing the matter as an abstract problem, I had forgottenhow personal and painful a thing it might be to you. I assureyou, however, that I never even knew that you had a brotheruntil you handed me the watch."

"Then how in the name of all that is wonderful did you getthese facts? They are absolutely correct in every particular."

"Ah, that is good luck. I could only say what was the balanceof probability. I did not at all expect to be so accurate."

"But it was not mere guesswork?"

"No, no: I never guess. It is a shocking habit -- destructive tothe logical faculty. What seems strange to you is only so becauseyou do not follow my train of thought or observe the small factsupon which large inferences may depend. For example, I beganby stating that your brother was careless. When you observe thelower part of that watch-case you notice that it is not only dintedin two places but it is cut and marked all over from the habit ofkeeping other hard objects, such as coins or keys, in the samepocket. Surely it is no great feat to assume that a man who treatsa fifty-guinea watch so cavalierly must be a careless man. Nei-ther is it a very far-fetched inference that a man who inherits onearticle of such value is pretty well provided for in other respects."

I nodded to show that I followed his reasoning.

"It is very customary for pawnbrokers in England, when theytake a watch, to scratch the numbers of the ticket with a pin-point upon the inside of the case. It is more handy than a label asthere is no risk of the number being lost or transposed. There areno less than four such numbers visible to my lens on the insideof this case. Inference -- that your brother was often at low water.Secondary inference -- that he had occasional bursts of prosper-ity, or he could not have redeemed the pledge. Finally, I ask youto look at the inner plate, which contains the keyhole. Look atthe thousands of scratches all round the hole -- marks where thekey has slipped. What sober man's key could have scored thosegrooves? But you will never see a drunkard's watch withoutthem. He winds it at night, and he leaves these traces of hisunsteady hand. Where is the mystery in all this?"

"It is as clear as daylight," I answered. "I regret the injusticewhich I did you. I should have had more faith in your marvellousfaculty. May I ask whether you have any professional inquiry onfoot at present?"

"None. Hence the cocaine. I cannot live without brainwork.What else is there to live for? Stand at the window here. Wasever such a dreary, dismal, unprofitable world? See how theyellow fog swirls down the street and drifts across the dun-coloured houses. What could be more hopelessly prosaic andmaterial? What is the use of having powers, Doctor, when onehas no field upon which to exert them? Crime is commonplacc,existence is commonplace, and no qualities save those which arecommonplace have any function upon earth."

I had opened my mouth to reply to this tirade when, with acrisp knock, our landlady entered, bearing a card upon the brasssalver.

"A young lady for you, sir," she said, addressing mycompanion.

"Miss Mary Morstan," he read. "Hum! I have no recollec-tion of the name. Ask the young lady to step up, Mrs. Hudson.Don't go, Doctor. I should prefer that you remain."