Thirteenth Lecture

Furthermore, we now finally come to a clear understanding of the origin of the so-called moonstones. Until now, they have often been considered a kind of deserters and defectors from the moon to the Earth. However, if they really originated from the flesh and bone of the moon, iodine would necessarily have to be detectable in them, or rather, they would have to consist entirely of iodine. Since neither of these things has yet been proven by the defenders of their selenitic origin, I find one of the following two opinions much more probable: either that they are to be regarded as a kind of gouty concretions, which are produced in the atmosphere, the joint fluid between two celestial bodies, which one might well compare to the bones of the universe; or that they are a cheese-like clot of ether, which, like milk, is coagulated by electrical and galvanic processes ... .“