Miscellanies. 213 



40. Notice of a Chemical Examination of a Specimen of Native Iron, 

 from the east hank of the Great Fish River, in South Africa ; by Sir 

 John F. W. Herschel.* 



The [portion analyzed of the] specimen in question weighed originally 

 24"79 grains, 512 of which were separated, and submitted to a hasty pre- 

 liminary examination for the detection of nickel, if any ; but the quantity 

 proving too small, the whole of the remainder was operated on in a subse- 

 quent trial. 



The iron was highly malleable and tenacious, and apparently of excel- 

 lent quality, with a somewhat whiter and more silvery lustre than belongs 

 to the metal in its ordinary state, and apparently little liable to oxidation, 

 qualities which are observed in iron, of what is usually considered un- 

 doubted meteoric origin. 



I should' not think it necessary to detail the steps of the analysis by 

 which the presence of nickel in the proportion of 4'6l per cent, was de- 

 monstrated, but for a peculiarity in one pait of the process by which an 

 inconvenience of frequent occurrence in chemical operations, and of a 

 very embarrassing nature, was obviated, and which may prove useful as a 

 hint to young analysts in other cases. 



18'67 grains of the iron in one piece were digested in dilute nitric acid, 

 which dissolved the whole, with the exception of a trifling quantity of 

 black scaly matter, apparently amounting to about a quarter of a grain.t 

 Towards the end of the solution the iron more than once brightened on 

 the surface, and assumed that peculiar and singular state of resistance to 

 the action of the acid which I have described in the Annates de Chimie 

 for September, 1833, and which has since been the subject of so much 

 interesting discussion by Professor Schoenbein, Mr. Faraday, and others. 

 In consequence, it was necessary to apply and maintain heat to complete 

 the solution. 



The nitric solution was evaporated to dryness, water added, and evapo- 

 rated a second and third time. By this the whole of the iron was perox- 

 idized, and nearly the whole separated. It was then diffused and boiled 

 in water, to which a few drops of nitric acid were added, to take up any 

 oxide of nickel which might have been deprived of its acid by overheat- 

 ing, and set aside for subsidence, filtration being out of the question. 



After standing a week, however, it was still perfectly opake, and loaded 

 with suspended peroxide of iron, and to get rid of this was the next object. 



* Read before the Literary and Scientific Institution of South Africa : now ex- 

 tracted from Sir James E. Alexander's " Expedition of Discovery into the interior 

 of Africa." Lond. 1838, vol. ii. Appendix, p. 272. The specimen had been found 

 by Sir James E. Alexander, and presented by him to the Institution. 



t This black scaly matter was in all probability ^rapAiie— Edit. Lond. and Ed. 

 Phil. Mag. 



