3^a Memoir tn the Stones /aid to 



fpecimehs of the ftoncs which have fallen in France are a 

 little more charged with iron than thofe of other countries ; 

 but as this metal exifts in them, for the moft part, in dillin<ii 

 globules which cannot be pulverized, they could have no in- 

 fluence on the refuhs of the analyfis, as the earthy part was 

 Cfted through a fine fieve. 



All the Uones which have fallen to the earth, and particu- 

 larly in France, contain, as I have already mentioned feveral 

 times, Eflobules of iron in a metallic (late more or lefs di- 

 llinft, fome of which weigh from fortv to fixty Eiicrlifh grains. 

 It appeared to me of importance to fubjeda this iron to fome 

 analytical trials in order to afccrtain the nature of their con- 

 ■iVituent principles ; but before I give the refults it mav be of 

 utilitv that I ihould fird give an account of their phvfical 

 chara6fers. Thefe globules are much whiter than common 

 iron; their colour approaches that of tin ; their hardnefs is 

 alfo greater, and confequently they are more difficult to be 

 forged. 



'I'liis metal diflblves eafilv, and with effervefcence, in all 

 thofe acids which diflolve common iron ; but inftead of giving 

 pure hvdrogen gas, it furnifhes hydrogen gas very fenfibly ful- 

 phurated. A part onlv of this hvdrogen gas, indeed, is 

 combined with the fulphur ; for, having made it to pafs 

 through water and cautiic alkalies, the greater part of this 

 fluid was not dill'olved ; and after having made the different 

 liquids here mentioned to pafs in the fame manner, no fen- 

 iible figns of fulphur were given by reagents ; but the water 

 and the alkalies were manifelUy hydro-fulphurated, fince they 

 then precipitated black the greater part of metallic folutions, 

 and particularly lead. This fulphurated hydrogen gas exhi- 

 bited to me a phaenomenon which, as far as I know, has 

 never been before obferved in its combination with water — 

 I mean a very fpectly decompofition which it experienced in 

 ■a flafl; perfectly clofed in which it had been preferved for 

 fome davs. At ihe end of that time there were at the bot- 

 tom of the water a great many fmall white laminae, and the 

 water had no odour: it no longer precipitated folutions of 

 lead. Thi-: cas then had experienced complete decompofi- 

 tion. 



The folution of this iron in muriatic acid was precipitated 

 by anmionia, of which a fuperabundance was added. The 

 liquor when filtered had a colour inclining to purple ; the 

 oxide of iron, when waflied and calcined, was of a brown 

 colour, and had fenfibly increafed in weight. The ammo- 

 niacal liquor when fubje6ted to evaporation depofited flight 

 traces of iron, but as long as there was ammonia in excefs 



it 



