OF ARTS AND SCIENCES. 479 



Bandeisen, and Fiilleisen, which he also designated respectively as 

 Kamacite, Taenite, and Plessite. 



In the year 1864, Gustav Rose, in liis " Beschreibung und Ein- 

 theilung der Meteoriten," distinctly i^ointed out the octahedral ar- 

 rangement of the plates which form the Widmanstattian figures, and 

 compared the structure of meteoric iron with the lamellar structure 

 of many leucite and magnetite crystals, regarding the crystalline mass 

 as consisting of scales or plates of iron separated by laminae of the 

 iron and nickel alloy which Reichenbach called Taenite. 



In 1848, Neumann,* in studying the structure of the Hauptmanns- 

 dorf (Braunau) iron, concluded that the fine linear markings which 

 appear on etching the faces of the remarkable cubic forms obtained 

 by fracture were essentially distinct from the Widmanstattian figures, 

 and such lines have since been known as Neumann lines, and have 

 been supposed to indicate a cubic structure, just as the Widmanstattian 

 figures had been supposed to mark solely an octahedral structure. 



On this basis, iron meteorites are now generally classified under 

 two chief groups, as the octahedral and the cubic. This distinc- 

 tion, originally made by Gustav Rose, has been brought into promi- 

 nence by Dr. Brezina in his I'ecent catalogue of the collection of 

 meteorites at the Vienna Museum, and in this catalogue both the 

 cubic and octahedral meteorites have been further subdivided by him 

 into numerous sub-groups, marked solely by the width and other 

 features of the figures or lines. 



That such a classification cannot be natural or fundamental is 

 shown by the disagreement of equally competent observers in regard 

 to the character of the figures or lines in special cases, and also by 

 the circumstance that the figures may appear very differently on sepa- 

 rate masses of the same fall, and even on different parts of the same 

 section. For example, the iron from Ovifack, Greenland, in regard 

 to whose meteoric origin there has been so much question, is described 

 both by Dr. J. Lawrence Smith and Daubree as yielding distinct 

 well-marked Widmanstattian figures, while Dr. Brezina insists that 

 it shows absolutely none. In like manner, the well-known iron of 

 Santa Catarina is described by Daubree, Damour, and others, as ex- 

 hibiting distinct Widmanstattian figures, while Dr. Brezina not only 

 asserts that no figures could be developed on any specimens which 

 have come under his notice, but even calls in question the discrimina- 

 tion of the eminent mineralogist just quoted. Again, Dr. Brezina, 

 in criticising some observations of Dr. Walter Flight of the British 



* Naturwiss. Abhandlung ber. v. Haidinger, Bd. iii. Abth. ii. p. 45. 



