Dr. Oliver Wendell Holmes is of opinion that “Memory, imagination, old sentiments and associations, are more readily reached through the sense of smell than by almost any other channel.” The probable reason for this strange connection between the sense of smell and the mind is, he tells us, “because the olfactory nerve is the only one directly connected with the hemispheres of the brain--the part in which we have every reason to believe the intellectual processes are carried on. To speak more truly,” he continues, “the olfactory nerve is not a nerve at all, but a part of the brain in intimate connection with its anterior lobes. Contrast the sense of taste as a source of suggestive impressions with that of smell. Now the nerve of taste has no immediate connection with the brain proper, but only with the prolongation of the spinal cord.” Curiously enough, it was in connection with a scent that I ultimately succeeded in recalling where and under what circumstances I had seen the face of which I was in search, and but for the fact of my having smelt a particular odour in a particular place this narrative would never have been written. I have said that when I smelt tobacco I felt that I was, as the children say, “getting warmer.” But, unfortunately, tobacco in the shape of pipe, cigar, or cigarette is in my mouth whenever I have an excuse for the indulgence, and often when I have none. Hence, though the face I sought seemed more than once to loom out at me through tobacco smoke, I had watched too many faces through that pleasing mist to be able to recall the particular circumstances under which I had seen the one in question. Nevertheless, it was tobacco which ultimately gave me my clue. The morning was very windy, and I had three times unsuccessfully essayed to light my cigar with an ordinary match. In despair--for in a general way I hate fusees like poison--I bought a box of vesuvians which an observant and enterprising match-vendor promptly thrust under my nose. As I struck the vile thing and the pestilent smell assailed my nostrils, the scene I was seeking to recall came back to me. I was sitting in a third-class smoking carriage on the London, Tilbury, and Southend Railway, and opposite to me was a little talkative man who had previously lit his pipe with a fusee. I saw him take out the box evidently with the intention of striking another, and then I heard a voice say, “For heaven’s sake, sir, don’t stink the carriage out again with that filthy thing! Pray allow me to give you a match.” The speaker was sitting directly in front of me, and as I recalled his face while I stood there in the street with the still unlighted cigar between my lips, the open box in one hand and the now burnt-out fusee arrested half-way toward the cigar-tip in the other, I knew that his face was the face of Captain Shannon. CHAPTER VI I MAKE UP MY MIND TO FIND CAPTAIN SHANNON