The gases of Francis I operated with fatal effect upon the vandals who broke open his coffin, in the time of the French Revolution, to rob it of its treasures. Books on hygiene teem with examples of the lethal properties of an atmosphere containing carbonic acid in excess. A familiar instance is that of the passengers of the ship _Londonderry_, in 1848, 150 of whom were shut up by the captain during a storm, in the steerage 18 × 11 × 7 feet. Seventy of them died in an incredibly short space of time, with convulsions and bleeding at the eyes and ears. Haguenot reports that, in 1744, the corpse of a monk of the Penitent Order, who had been buried in a vault under the church, was exhumed in the church of Notre Dame, at Montpellier, France. A man descended into the vault to remove the cadaver, but, before he got quite down, he was taken with convulsions, and fell unconscious into the vault, where he died of suffocation. A monk went down to rescue him, but he too was taken sick, and, on having been pulled out immediately, succumbed quickly. A third, who had the courage to follow his example, fell dead without being able to retire. The same fate was reserved for a fourth victim,—a brother of the first. The bodies were pulled out with hooks; the stench of their clothing was unbearable. Lights held near the opening of the vault extinguished; dogs, cats, and birds, on being brought in contact with the poisonous gases, died, with all symptoms of a severe convulsion, in a few minutes. Some of the mephitic gas was bottled; but when experimented with after two and one-half months, it still had all of its dangerous qualities. In 1749, when new vaults and graves were made in the St. Eustachius Church at Paris, France, cadavers were dug up and placed temporarily in an old vault of the church, which had remained locked a long time. Children coming to church to prepare for confirmation, and even adults, fainted on entering the sacred edifice, and some had serious attacks of illness. The same took place in St. Sebastian Church at Madrid, Spain, in 1786; three times a grave burst open, in which, but a short time before, a very corpulent lady had been buried. The horrible smell that arose from this grave prevented the reading of the holy mass at the high altar during a period of eight days. At one time the Parish Church of Metz was so infected by the gases of a female corpse that it had to be abandoned, and the divine service removed to another church. In 1841 two men who had some work to do in a grave in St. Botolph’s Churchyard, Aldgate, England, died almost instantly on entering it.