109 



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. 



An Account of some Stones said to have fallen on the Earth in France ; 

 and of a Lump of native Iron, said to have fallen in India. By the 

 Right Hon. Charles Greville, F.R.S. Read January 27, 1803. 

 [Phil. Trans. 1803, p. 200.] 



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 de Montpellier for that year. For the third spe- 

 cimen Mr. Greville is indebted to the Marquis de Dree. It is a frag- 

 ment broken from a stone of 22 pounds weight, which fell near Ville- 

 franche, in Burgundy, the 12th of March, 1798. This, like the 

 former ones, was accompanied by a meteor ; and all three have pre- 

 cisely 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 



