An Account of a Meteor. 153 



oxid of iron. The fluid was filtered, and heated on a 

 sand bath, to expel the excess of ammonia, and to pre- 

 cipitate any additional portion of oxid of iron which it 

 might have suspended, but none was obtained. 



6. — The precipitate being washed, collected, dried 

 and ignited strongly, in a platinum crucible, had a dark 

 brown colour, inclining to red, and weighed 38 gi'ains. 

 Six grains of this weight were allowed for what adhered 

 to the filter, which was accurately weighed before it was 

 used, and after it had been thoroughly dried on a heated 

 slab of Portland stone, and the difference of weight was 

 6 grains. 



The oxid of iron thus obtained was not in the highest 

 state of oxidizement ; for, it was completely, although 

 not very powerfully attractable by the magnet, by which 

 the whole of it was actually transferred from a plate of 

 glass to a wine-glass. It ought to have been oxidized 

 to a maximum, considering the process by which it v/as 

 obtained ; — possibly some adhering ammonia, and a por- 

 tion of charcoal, which accidentally got into the crucible, 

 might have abstracted a part of its oxigen, with the aid 

 of heat, and indeed heat alone would have expelled a 

 portion of oxigen. 



7. — The fluid from which the oxid of iron had been 

 separated, had now a greenish colour, precisely similar 

 to what it had in No. 2. Carbonat of potash produced 

 no precipitate, but, caustic potash threw down a pretty 

 voluminous fleecy white precipitate. Being separated 

 by the filter, dried, collected, and moderately heated, it 

 became almost black ; but, on being heated strongly in 

 a platinum crucible, covered by an inverted crucible of 

 the same metal, it became white. It weighed 13 grains. 

 It dissolved rapidly in sulphuric acid, and afforded, by 

 evaporation, prismatic crj^stals, which had an acidulous, 

 bitter taste ; the former arising from a redundancy of the 

 sulphuric acid ; — it afforded a white precipitate, with 

 caustic potash — suffered the aqueous fusion, and became 

 a dry mass, on a live coal. From all these considera- 

 tions, it was concluded, that the 13 grains were magnesia. 



These crystals of sulphat of magnesia had a very slight 



