188 THE ROYAL SOCIETY OF CANADA 



were the portions of the two sides and end previously described ; they 

 undoubtedly represented too some of the later fracturings incident 

 to the strains to which the meteorite was subjected in its traverse 

 of the earth's atmosphere. 



Internally the meteorite presents a grayish brown micro-granular 

 ground mass traversed by small veinlets of nickel-iron alloy. These 

 veinlets are often interrupted and seldom exceed a millimetre in 

 width. In an exceptional case, however, an expansion of one of them 

 attained a width varying from 3 to 6 millimetres over a length of 

 25 millimetres. When this expansion was rubbed down to a smooth 

 polish it showed a number of fractures partially filled with siliceous 

 matter which had plainly undergone a certain measure of alteration 

 from weathering agencies. Treatment of the polished surface with 

 dilute nitric acid failed to develop any well defined figure ; but unde • 

 a magnification of 40 to 50 diameters a small area measuring about 

 4 or 5 square millimetres was seen to possess a finely laminated 

 structure, while the edges of the laminae presented a very uniform 

 fluted appearance. Other portions of this polished surface examined 

 under like conditions showed a minutely granular groundmass tra- 

 versed by numbers of fine zig-zag lines meeting or intersecting each 

 other at all angles. They are probably cooling fractures and some 

 of them appear to have been filled or partially filled from still fluid 

 residuum. 



In thin section under the microscope the groundmass of the 

 meteorite shows a more or less interrupted network of metallic nickel- 

 iron alloy enclosing irregular patches of enstatite. Some of the en- 

 statite appears colourless in the section, but much of it shows a brown- 

 ish tinge particularly along the edges in contact with the nickel- 

 iron. This tinge, however, is plainly not a property of the enstatite 

 tself, but is imparted to it through the presence of some as yet un- 

 dentified sulphur compounds, for when a fragment of the meteorite 

 is treated with dilute hydrochloric acid disengagement of gases, 

 smelling of sulphuretted hydrogen, is set up and in the end there 

 remains a residue consisting of colourless enstatite with here and 

 there a minute flake of daubréelite, and less often a little graphite. 



Cleavage cracks in the enstatite are seen quite frequently to 

 have been invaded by still fluid metal and are now occupied by thin 

 films of nickel-iron alloy. 



Optical Properties 



For the following data the writers are indebted to Mr. Eugene 

 Poitevin of the Division of Mineralogy of the Geological Survey 

 who has investigated the optical properties of the enstatite of this 



