Mons. Alphonse Karr writes as follows in his _Les Femmes_:--"When I wish to become invisible, I have a certain rusty and napless old hat, which I put on as Prince Lutin in the fairy tale puts on his chaplet of roses; I join to this a certain coat very much out at elbows: _eh bien_! I become invisible! Nobody on the street sees me, nobody recognizes me, nobody speaks to me." And yet I do not doubt that the majority of M. Karr's friends and acquaintances, as is the case with the friends and acquaintances of nearly every one else, are well-disposed, good-hearted, average persons, who would be heartily ashamed, if it could be brought home to them, of having given him the go-by under such circumstances. What, then, was the difficulty? In what consisted this change in the man's appearance, so signal that he trusted to it as a disguise? What was there in hat and coat thus to eclipse the whole personality of the man? There is a certain mystery in the philosophy of clothes too deep for me to fathom. The matter has been descanted upon before; the "Havamal, or High Song of Odin," the Essays of Montaigne, the "Sartor" of Thomas Carlyle, all dwell with acuteness upon this topic; but they merely give instances, they do not interpret. I am continually meeting with things in my intercourse with the world which I cannot reconcile with any theories society professes to be governed by. How shall I explain them? How, for example, shall I interpret the following cases, occurring within my own experience and under my own observation?