actually inverted, in order to suit this structure of the eye. The
humours of the eyes of birds are chemically of the same nature as
those of quadrupeds.
It is also observed, that the crystalline in all animals is not through— out of the same density; the result of some experiments made on this subject being that its density increases from the circumference to the centre, as the square roots of the quantities pared away from the external part.
Lastly, it is suggested, that since we know that albumen can be coagulated by Various methods, it is not unlikely that this may hap- pen likewise in the human eye, and be the cause of disorder known by the name of Cataract. An attention to this complaint, especially in gouty persons, is strongly recommended; as some important con- clusions, it is thought, may be drawn as to the influence of phosphoric acid in causing that disorder, by the common effect of acids in coa- gulating albumen.
Mr. Greville, conceiving that the experiments and observations made by Mr. Howard on certain metalline substances said to have fallen on the earth, and the accurate descriptions which Count de Bournon has given of these substances, have established the fact that a number of stones, asserted to have fallen under similar circum- stances, have precisely the same character, is here pleased to commu- nicate to the Society three more instances of such singular productions of nature, which have of late been noticed in France.
The first is a specimen broken from a stone of about 15 inches diameter, preserved in the Museum of Bourdeaux, and which is said to have fallen near Roqueford, in the Landes, on the 20th of August, 1789, during the explosion of a meteor. It broke through the roof of a cottage, and killed a. herdsman and some cattle.
The second is part of a stone preserved in the collection of Mons. St. Amand, which was one of the numbers that fell in the year 1790, in three different parishes in Armagnac, some of which weighed no less than 25 pounds. The fact of this shower of stones was at the time verified by the Mayor of Armile, and is published in the Journal des Sciences Utiles dc Montpellier for that year. For the third specimen Mr. Greville is indebted to the Marquis de Drée. It is a fragment broken from a stone of 22 pounds weight, which fell near Villefranche, in Burgundy, the 12th of March, 1798. ' ‘his, like the former ones, was accompanied by a meteor; and all three have precisely the same character, texture, and appearance._
We are indebted to Mr. Greville for a new evidence, and he says, the only one he has yet met with, that seems to ascertain the origin of native iron, Which, from analysis, had been suspected to have a
