A rational theory is offered by M. de Choiseul, on the formation of the concretions. "Their figure is diver sified, according to the size of the aperture through which the humidity composing them exudes. Water, in the course of penetrating the mass of the upper strata, acquires the property of dissolving calcareous substan ces. In penetrating deeper into the strata, it absorbs more, and the quantity is always augmenting, until it reaches the internal surface of the fissures in the vault, where it forms into the shape of drops. But there the water of the drop evaporates, and the calcareous matter which it held in solution remains behind. Additional moisture succeeds, by the evaporation of which the size of the stalactite is increased. Like icicles hanging from rocks washed by a torrent, the stalactites grow larger and larger, and continue extending the conical figure produced by their original mode of formation. But should the water filtrate in greater abundance from above, the drops will not have time to evaporate in their accession to the stalactite ; whence the superincumbcnt weight will occasion their fall on the bottom of the ca vern, from which calcareous concretions will arise, in proportion as the upper ones extend ; and at length their extremities will meet. This union produces a column, at first imperfect, but gradually enlarging, and becoming perfect, from the same causes that are the original source of the stalactite." Most of the columns thus formed in the grotto of Antiparos have been injured by the indiscreet curiosity of travellers, either for the purpose of examining their internal organization, or of enriching their cabinets. But new ones would continually be completed, were the portions approaching towards each other left un touched.
Sonic of the concretions depending from above stretch into a kind of thin curtain, almost transparent, and ap pearing of still greater tenuity, by means of torches art fully disposed. But the concurring testimony of credible travellers is against that brilliancy and splendour in the grotto which others have ascribed to it ; and the lanes of diamonds, blood-coloured walls, and shining stars, which they fancifully suppose to have beheld, are, at most, but a faint reflection from the white incrustations of calca reous matter.
In the midst of what is called the hall, which is the greatest vacuity of the grotto, there is an immense sta lagmite, above twenty feet in diameter, and twenty-four in height. This superb concretion has been denomi nated the altar, ever since the marquis de Nointel cele brated a midnight mass during his visit to the cavern in 1673 ; an event which is perpetuated by an inscription on a rock near its entrance, still entire. That nobleman, who was ambassador from Louis XIV. of France to the Ottoman Porte, passed the three festivals of Noel* in the grotto, attended by above 500 persons, consisting of those in his own train, merchants, corsairs, and the peo ple of the country who followed him. Men were posted from the extremity to the entrance, to communicate the moment when the host was elevated, to those without, who discharged their fire-arms, and sounded trumpets, and other musical instruments, to render the consecra tion more impressive. The grotto itself was illumi nated by 100 large torches of yellow wax, and 400 lamps burned in it day and night. The whole ceremony being ended, he ordered an inscription to be engraved on the base of the concretion, intimating, that at midnight of Christmas 1673 he bad celebrated mass.
It is not absolutely certain whether the utmost extre mity of the cavern has ever been attained. The inha bitants of Antiparos affirm that it reaches below the sea, and that a goat having once accidentally wandered into it, was found in the island of Nio, between thirty and forty miles distant. But although this is most likely a fabulous report, it is not improbable that many recesses yet remain to be explored. (c)