There are few persons who have not, at some period of their lives, amused themselves in retracing the steps by which particular conclusions of their own minds have been attained. The occupation is often full of interest and he who attempts it for the first time is astonished by the apparently illimitable distance and incoherence between the starting-point and the goal. What, then, must have been my amazement when I heard the Frenchman speak what he had just spoken, and when I could not help acknowledging that he had spoken the truth. He continued:

      “We had been talking of horses, if I remember aright, just before leaving the Rue C ——. This was the last subject we discussed. As we crossed into this street, a fruiterer, with a large basket upon his head, brushing quickly past us, thrust you upon a pile of paving stones collected at a spot where the causeway is undergoing repair. You stepped upon one of the loose fragments, slipped, slightly strained your ankle, appeared vexed or sulky, muttered a few words, turned to look at the pile, and then proceeded in silence. I was not particularly attentive to what you did; but observation has become with me, of late, a species of necessity.