52 RECORPS OF THE AUSTRALIAN MUSEUM. 



within a quarter of an inch from the edge. The plates are about 

 two-thirds of the natural size and represent the Widmanstatten 

 figures as seen under different aspects of retlected light. The 

 markings consist of bands of beam iron (kamacite), running in 

 three directions, which cross each other approximately at angles 

 of 60°. Under the glass the bands themselves shew usually two, 

 and sometimes three series of finely-etched parallel lines, crossing 

 at varying angles. Troilite is freely distributed throughout, 

 occurring in nodules (PI. xiii., right-hand top corner), and in 

 the smaller patches and cracks. The latter are numerous, and 

 mostly separate the bands of beam iron from each other. The largest 

 nodule observed was one and a half cmm. long and one cm. wide, and 

 possessed a dark bronze-like metallic lustre. The nodules are lined 

 by a darker substance, usually forming a very thin layer, which is 

 thickened in places and continued into the cracks. The iron im- 

 mediately surrounding the nodules is somewhat more brilliant 

 than that further removed, but no defined line is generally to be 

 seen separating this brighter iron from the remainder. The etched 

 iron shews in places a very fine irregular mottling, forming occa- 

 sionally more or less regular lines ; but this formation appears to 

 be independent of the crystalline structure. Very small specks 

 and strings of bright particles are very sparingly distributed 

 throughout the iron, and in a relatively larger quantity occur with 

 the troilite. By dissolving 6-2114 grms. of the iron in hydrochloric 

 acid in the cold, a residue containing '0386 grm. of a black 

 powder and '0014 grm. of bright metallic particles was left undis- 

 solved. The latter under the microscope were seen to consist of a 

 mixture of brilliant grains and needles of a steel grey colour. The 

 mass of the iron is almost entirely a mixture of beam iron (kama- 

 cite) and troilite, but taenite and plessite do not appear to be 

 developed. The bright grains and prisms are no doubt a mixture 

 of the phosphides of iron and nickel (schreibersite and rhabdite), 

 and the black powder of carbon and carbide of iron. I hope, 

 however, to have a further opportunity of more closely examining 

 this residue. The small quantity of residue insoluble in boiling 

 acids consists mainly of carbon. 



Analysis. — To obtain an average sample for analysis, about 

 twenty grams of small chippings were cut off from portions visibly 

 free from troilite. 



I. 3 '0702 grams of the above were dissolved in hydrochloric 

 acid, and after separating the residue and precipitating the trace 

 of copper present, the method of analysis was that adopted by 

 Stanislas Meunier.* From the solution acidified with acetic acid, 

 the nickel, cobalt and part of the iron were precipitated by 



* Stanislas Meunier, Encyclopedie chimique, ii., 1884, App. 2, Meteor- 

 ites, p. 26 et seq. 



