"In this case it certainly is so," I replied, after a little thought. "The thing, however, is, as you say, of the simplest. Would you think me impertinent if I were to put your theories to a more severe test?"
"On the contrary," he answered, "it would prevent me from taking a second dose of cocaine. I should be delighted to look into any problem which you might submit to me."

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

I handed him over the watch with some slight feeling of amusement in my heart, for the test was, as I thought, an impossible one, and I intended it as a lesson against the somewhat dogmatic tone which he occasionally assumed. He balanced the watch in his hand, gazed hard at the dial, opened the back, and examined the works, first with his naked eyes and then with a powerful convex lens. I could hardly keep from smiling at his crestfallen face when he finally snapped the case to and handed it back.
"There are hardly any data," he remarked. "The watch has been recently cleaned, which robs me of my most suggestive facts."
"You are right," I answered. "It was cleaned before being sent to me." In my heart I accused my companion of putting forward a most lame and impotent excuse to cover his failure. What data could he expect from an uncleaned watch?
"Though unsatisfactory, my research has not been entirely barren," he observed, staring up at the ceiling with dreamy, lack-lustre eyes. "Subject to your correction, I should judge that the watch belonged to your elder brother, who inherited it from your father."
"That you gather, no doubt, from the H. W. upon the back?"
"Quite so. The W. suggests your own name. The date of the watch is nearly fifty years back, and the initials are as old as the watch: so it was made for the last generation. Jewelry usually descends to the eldest son, and he is most likely to have the same name as the father. Your father has, if I right, been dead many years. It has, therefore, been in the hands of your eldest 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 of prosperity, and finally, taking to drink, he died. That is all I can gather."
I sprang from my chair and limped impatiently about the room with considerable bitterness in my heart.
"This is unworthy of you, Holmes," I said. "I could not have believed that you would have descended to this. You have made inquires into the history of my unhappy brother, and you now pretend to deduce this knowledge in some fanciful way. You cannot expect me to believe that you have read all this from his old watch! It is unkind, and, to speak plainly, has a touch of charlatanism in it."

"My dear doctor," said he, kindly, "pray accept my apologies. Viewing the matter as an abstract problem, I had forgotten how personal and painful a thing it might be to you. I assure you, however, that I never even knew that you had a brother until you handed me the watch."
"Then how in the name of all that is wonderful did you get these facts? They are absolutely correct in every particular."

"Ah, that is good luck. I could only say what was the balance of probability. I did not at all expect to be so accurate."
"But it was not mere guess-work?"
"No, no: I never guess. It is a shocking habit,—destructive to the logical faculty. What seems strange to you is only so because you do not follow my train of thought or observe the small facts upon which large inferences may depend. For example, I began by stating that your brother was careless. When you observe the lower part of that watch-case you notice that it is not only dinted in two places, but it is cut and marked all over from the habit of keeping other hard objects, such as coins or keys, in the same pocket. Surely it is no great feat to assume that a man who treats a fifty-guinea watch so cavalierly must be a careless man. Neither is it a very far-fetched inference that a man who inherits one article 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 they take a watch, to scratch the number of the ticket with a pin-point upon the inside of the case. It is more handy than a label, as there is no risk of the number being lost or transposed. There are no less than four such numbers visible to my lens on the inside of this case. Inference,—that your brother was often at low water.

Secondary inference,—that he had occasional bursts of prosperity, or he could not have redeemed the pledge. Finally, I ask you to look at the inner plate, which contains the key-hole. Look at the thousands of scratches all round the hole,—marks where the key has slipped. What sober man's key could have scored those grooves? But you will never see a drunkard's watch without them. He winds it at night, and he leaves these traces of his unsteady hand. Where is the mystery in all this?"

"It is as clear as daylight," I answered. "I regret the injustice which I did you. I should have had more faith in your marvellous faculty. May I ask whether you have any professional inquiry on foot at present?"
"None. Hence the cocaine. I cannot live without brain-work. What else is there to live for? Stand at the window here. Was ever such a dreary, dismal, unprofitable world? See how the yellow fog swirls down the street and drifts across the dun-colored houses.

What could be more hopelessly prosaic and material? What is the use of having powers, doctor, when one has no field upon which to exert them? Crime is commonplace, existence is commonplace, and no qualities save those which are commonplace have any function upon earth."

––En este caso es as, desde luego ––repliqu yo, tras pensrmelo un poco– –. Sin embargo, como usted mismo ha dicho, se trata de un asunto de lo ms sencillo. Me considerara impertinente si sometiera sus teoras a una prueba ms estricta?
––Al contrario ––respondi l––. Eso me evitar tener que tomar una segunda dosis de cocana. Estar encantado de considerar cualquier problema que usted me plantee.
––Le he odo decir que es muy difcil que un hombre use un objeto todos los das sin dejar en l la huella de su personalidad, de manera que un observador experto puede leerla. Pues bien, aqu tengo un reloj que ha llegado a mi poder hace poco tiempo. Tendra la amabilidad de darme su opinin sobre el carcter y las costumbres de su antiguo propietario?
Le entregu el reloj con un ligero sentimiento interno de regocijo, ya que, en mi opinin, la prueba era imposible de superar y con ella me propona darle una leccin ante el tono algo dogmtico que adoptaba de vez en cuando. Holmes sopes el reloj en la mano, observ atentamente la esfera, abri la tapa posterior y examin el engranaje, primero a simple vista y luego con ayuda de una potente lupa. No pude evitar sonrer al ver su expresin abatida cuando, por fin, cerr la tapa y me lo devolvi.
––Apenas hay ningn dato ––dijo––. Este reloj lo han limpiado hace poco, lo cual me priva de los indicios ms sugerentes.
––Tiene razn ––respond––. Lo limpiaron antes de envirmelo.
En mi fuero interno, acus a mi compaero de esgrimir una excusa de lo ms floja e impotente para justificar su fracaso. Qu datos haba esperado encontrar aunque el reloj no hubiera estado limpio?
––Pero aunque no sea satisfactoria, mi investigacin no ha sido del todo estril ––coment, dirigiendo hacia el techo la mirada de sus ojos soadores e inexpresivos––. Salvo que usted me corrija, yo dira que el reloj perteneci a su hermano mayor, que a su vez lo hered de su padre.
––Supongo que eso lo ha deducido de las iniciales H.W. grabadas al dorso.
––En efecto. La W sugiere su apellido. La fecha del reloj es de hace casi cincuenta aos, y las iniciales son tan antiguas como el reloj. Por lo tanto, se fabric en la generacin anterior. Estas joyas suele heredarlas el hijo mayor, y es bastante probable que ste se llame igual que el padre. Si no recuerdo mal, su padre falleci hace muchos aos. Por lo tanto, el reloj ha estado en manos de su hermano mayor.
––Hasta ahora, bien ––dije yo––. Algo ms?
––Era un hombre de costumbres desordenadas..., muy sucio y descuidado. Tena buenas perspectivas, pero desaprovech las oportunidades, vivi algn tiempo en la pobreza, con breves intervalos ocasionales de prosperidad, y por ltimo se dio a la bebida y muri. Eso es todo lo que puedo sacar.
Me puse en pie de un salto y renque impaciente por la habitacin, enormemente indignado.
––Esto es indigno de usted, Holmes ––dije––. Jams habra credo que caera usted tan bajo. Ha estado usted investigando la historia de mi desdichado hermano, y ahora finge haber deducido todo ese conocimiento por medios fantsticos. No esperar que me crea que ha visto todo eso en este viejo reloj! Es una grosera y, para serle franco, parece ms propio de un charlatn.
––Querido doctor ––dijo en tono suave––, le ruego que acepte mis disculpas. Al considerar el asunto como un problema abstracto, olvid que para usted se trata de algo muy personal y doloroso. Sin embargo, le aseguro que, hasta que me ense el reloj, no saba que hubiera tenido usted un hermano.
––Y entonces, cmo diablos averigu todo eso? Porque ha acertado de lleno en todos los detalles.
––Ha sido pura suerte. Me limit a decir lo que pareca ms probable. No esperaba acertar en todo.
––No han sido puras conjeturas?
––No, no; yo nunca hago conjeturas. Es un hbito nefasto. Destruye las facultades lgicas. Lo que a usted le parece tan extrao, lo es slo porque no ha seguido mi cadena de pensamientos ni se ha fijado en los pequeos datos de los que pueden extraerse importantes inferencias. Por ejemplo, empec afirmando que su hermano era descuidado. Si se fija en la parte inferior de la tapa del reloj, ver que no slo tiene un par de abolladuras, sino que adems est rayado y araado por todas partes, a causa de la costumbre de meter en el mismo bolsillo otros objetos duros, como monedas o llaves. Como ve, no es ninguna proeza suponer que un hombre que trata tan a la ligera un reloj de cincuenta guineas debe ser descuidado. Tampoco es tan descabellado deducir que un hombre que hereda un artculo tan valioso tiene que estar bien provisto en otros aspectos.
Asent para dar a entender que segua su razonamiento.
––Es costumbre de los prestamistas ingleses, cuando alguien empea un reloj, grabar el nmero de la papeleta con un alfiler en el interior de la tapa. Es ms cmodo que poner una etiqueta y no hay peligro de que el nmero se pierda o se traspapele. Y mi lupa ha descubierto nada menos que cuatro de esos nmeros en el interior de la tapa del reloj. Deduccin: su hermano pasaba apuros econmicos con frecuencia. Deduccin secundaria: de vez en cuando atravesaba perodos de prosperidad, pues de lo contrario no habra podido desempear la prenda. Por ltimo, le ruego que mire la chapa interior, donde est el agujero para dar cuerda. Fjese en que hay miles de rayas alrededor del agujero, causadas al resbalar la llave de la cuerda. Cree que la llave de un hombre sobrio dejara todas esas marcas? Sin embargo, nunca faltan en el reloj de un borracho. Le daba cuerda por la noche y dej la marca de su mano temblorosa. Qu misterio hay en todo esto?
––Est tan claro como la luz del da ––respond––. Lamento haber sido injusto con usted. Deb haber tenido ms fe en sus maravillosas facultades. Puedo preguntarle si en estos momentos tiene entre manos alguna investigacin profesional?
––Ninguna. De ah lo de la cocana. No puedo vivir sin hacer trabajar el cerebro. Qu otra razn hay para vivir? Mire por esa ventana. Alguna vez ha sido el mundo tan lgubre, triste e improductivo? Mire esa niebla amarilla que hace remolinos por la calle y se desliza ante esas casas grises. Puede haber algo ms desesperantemente prosaico y material? De qu sirve tener talento, doctor, si no se tiene campo en el que aplicarlo? Los delitos son vulgares, la existencia es vulgar, y en este mundo no hay sitio para lo que se salga de la vulgaridad.
Abr la boca para responder a su diatriba, pero en aquel momento, tras dar unos golpecitos en la puerta, entr nuestra casera, que traa una tarjeta en una bandeja de latn.
––Una seorita pregunta por usted, seor ––dijo, dirigindose a mi compaero.
––Miss Mary Morstan ––ley ste––. Hum! No me suena de nada el nombre. Diga a la seorita que suba, seora Hudson. No se vaya, doctor. Prefiero que se quede.