24 Professor Apjohn on a Meteoric Stone 



The peroxide of iron and oxide of chrome were next washed off the single 

 filter, and dissolved in muriatic acid. To the solution tartaric acid was then 

 added in such quantity that upon subsequently adding ammonia in excess there 

 was no precipitate. The iron was now thrown down as sesquisulphuret by the 

 hydrosulphate of ammonia, and the precipitate, when collected on a single filter, 

 was well washed with distilled water. It was then transferred to a porcelain 

 capsule, in it decomposed by nitro-muriatic acid, and after filtering to separate 

 sulphur, the solution was precipitated by the addition of ammonia in excess. The 

 peroxide of iron, when dried on a sand bath, weighed 14.42 grs. ; 13.23 grs. of 

 this exposed to a red heat were reduced to 6.29. Hence, 



13.23 : 6.29 : : 14.42 : 6.85, true weight of peroxide of iron. 

 31.07: 6.85:: 31.37: 6.91 



102.47 :6.91 :: 115.18 : 7.76, the peroxide of iron in the entire of the 

 fluxed portion of the meteorite. And 



41 : 36 : : 7.69 : 6.98, the corresponding weight of protoxide, which is 

 the form in which it exists in the stone. 



The solution from which the iron was thrown down by the hydro-sulphate of 

 ammonia, and which had a deep green colour, was concentrated on the sand bath, 

 then filtered to separate sulphur, and finally evaporated to dryness, and ignited in 

 a platinum crucible to destroy the tartaric acid. To the residue, which had a 

 carbonaceous appearance, nitre was added, and heat being applied, the charcoal 

 was burned off, and the oxide of chrome, at the same time, converted into 

 chromate of potash, the whole was then acted upon by distilled water, and thrown 

 upon a filter, which allowed the chromate of potash to pass through with carbo- 

 nate of potash and excess of nitre, and detained a small quantity of insoluble mat- 

 ter, of a rusty colour, (magnesia, with deutoxide of manganese,) which was es- 

 timated, though in consequence of an accident not with any great precision, to 

 amount to 1 .08 grs. 



The solution containing the chromate of potash was acidulated with muriatic 

 acid, boiled, and treated first with alcohol, and next with an excess of ammonia, 

 the former of which reduced the chromic acid to the state of chromic oxide ; 

 while the latter threw down the oxide from its combination with the muriatic acid. 

 After desiccation on the sand bath it weighed 9.87 grs. Of these 8.97 were 

 reduced by a red heat to 3.70. Hence, 



