I think 'twill not be denied, that laying up the Bodies in Caves was the original way of disposing of the dead; this was that of the _Phænicians_, and as they were the Men that with their Colonies peopled the Western parts of the World, 'tis more than probable they carried it along with them whither soever they went. Afterwards, as Men grew great and powerful, they erected noble and magnificent Monuments for themselves above ground; at length others of inferior degree imitated them, all leaving room enough and excluding the light: But then interring as we do now in the open Air, or in Temples, was never the manner till Christianity brought it in. Of the whole we have many Instances, and _Il Signior Abbate Bencini_, Bibliothecary of the _Propaganda_, a Gentleman of good Ancient Learning, assured me in the conversation I had with him on this Argument, that on the great Roads in most parts of _Italy_ little Catacombs have been and are still found under ground, and that 'twas the Custom to build little Houses over them. This, and the testimony of the Labourers whom I consulted on the matter, made me abandon an opinion of which I was once fond, that the Catacombs are of the Nature of our Gravel-pits, as old as the City itself, and yet out of them was taken the _Puzzolana_, the famous Ingredient in the _Roman_ Mortar. The same learned Gentleman added, relating to the marks of a Martyr, that they don't conclude much; that the so fam'd Cypher XP was in use among the Ancients long before Christianity begun: And when I ask'd him what the meaning of it might be among them? return'd, that 'twas compos'd of the two _Greek_ Letters Χ Ρ, under which something mystical was comprehended, but that he met with no Author that gave account what the mystery was. Thus, after a multitude of thoughts about the Catacombs, I'm forced to take up with this; so natural it is, arising from the sole Theory of the Place, and falls in so oppositely with the Religion and Practice of the Ancients, among whom the _Dii Manes_ were the Tutelary Gods of the Country, and _D. M._ at the head of an Inscription, argues the Moles, the Sepulchre, the Monument, _&c._ was in the primary intention made for and dedicated to the Soul. Upon the same Maxims, in Foreign expeditions, when a Hero died or was kill'd, as the Body was liable to a quick corruption, and for that Reason unfit to be transported entire, they fell on the expedient of Burning, in order to bring home the Ashes, to oblige the _Manes_ to follow, that so the Country might not be deprived of the Benefit of its tutelage. This I humbly conceive was the Original of Burning, which by Degrees became more and more universal, till at last the Pomp and Magnificence of it reconcil'd it to all that were able to go to the length of the expence.