Something may be due, also, to the mode in which they would sometimes close a narrow-necked vessel of glass. When it had received its contents, the glass of the neck would be heated, probably by the flame of a blowpipe, until it became soft and pliable. The sides would then be pressed together until they coalesced and became united, thus obliterating the orifice; or else molten glass would be carefully dropped on the lips of the mouth, until the whole was entirely coated over and perfectly closed. When either was followed and the work was done perfectly, the ampulla would be, in fact, hermetically sealed. The air would thus be excluded, and evaporation nearly arrested. Placed in a _loculus_ or grave in the dry earth of the catacombs, twenty-five or thirty-five feet beneath the surface of the earth, the ampulla would also be subjected to an ever-equable temperature of about 58° Fahr. Under such circumstances, especially if we admit the presence of some antiseptic ingredient, it may be possible that decomposition would be very slow. But, after all, the glass sides of these ampullæ are thin, and glass is porous, and sixteen centuries is a very long time. Even were the sides far thicker than they are, evaporation would have slowly taken place, the gaseous products of decomposition would have gradually passed through into the outer 212 atmosphere, and only the dry solid residuum would be left, as we ordinarily find it in the ampullæ from the catacombs. The case of the ampulla containing the blood of St. Januarius is not open to these doubts. We are not able to say, indeed, whether it was actually closed in either of the modes we have indicated. As it stands in the present reliquary, of which we have given an account, the mouth enters so deeply into the upper mass of soldering within the case that the eye cannot discover the manner of closure. Before it was placed in this reliquary, five hundred and seventy or seven hundred and thirty years ago, this could probably have been seen; but we have found no record throwing light on the subject. We presume it was done in one or the other of the modes we have described. It is certainly so tightly closed that not a drop of the liquid blood within has ever been known to ooze out.