THE NARRABURRA METEORITE. 239 
Plate 18 represents the fourth section also reduced to 33. 
Plate 19. This section, the third in order, is of the 
natural size, was etched by copper sulphate. It shows a 
nodule a.ua. of troilite; but much of the detail visible in the 
bromine etched sections is lost. The black semicircular 
patch to the left is a large troilite nodule, invested with 
bright kamacite. 
Plate 20 is an enlargement, by five diameters, of the part 
of the above section containing the nodule a.a. It has a 
dark roughly pentagonal nucleus, which may be a crystal. 
In the lower left hand corner is a portion of a troilite 
nodule invested with bright kamacite. 
Plate 21 represents the second section enlarged one and 
a half diameters. 
Plate 22 is from the first section enlarged two diameters. 
All the sections were etched by bromine water except 
the third shown in Plate 19. 
On the whole the structure of this meteorite appears to 
be unique, but it requires further investigation, and this 
brief account can only be regarded as a preliminary one. 
The troilite nodules were more readily acted upon by the 
bromine and their etched surfaces are distinctly depressed 
below the level of the rest of the meteorite. 
CHEMICAL COMPOSITION. 
Resinous Matter.—_Some of the sawdust, which had not 
come into contact with oil or lubricant of any kind was 
extracted with benzene, which had been redistilled until 
it leit no residue on evaporation in a clock glass. In one 
experiment it was found that 50 gms. of the sawdust 
yielded to the benzene °004 gm. of a resinous looking sub- 
stance, slightly tinged with brown, which when heated on 
platinum foil melted, burnt with a smoky flame and left 
no residue. The quantity was insufficient for further 
