XV. — GEOLOGY AND MINERALOGY. 127 



III.— COLLECTION OF METEORITES. 



The Meteorites are kept in a special case next to the metal 

 Nickel, which most of them contain. In course of time they will 

 form a larger and more systematic collection, although the 

 specimens are not very numerous as yet. Among them will be 

 found a cast of the Deniliquin or Baratta Meteorite, the original 

 of which is in possession of Mr. Russell, Government Astronomer, 

 and weighs 145 lbs. ; it has a specific gravity of 3'387 and is 

 mostly composed of the minerals Enstatite, Olivine, and Nickel- 

 iferous Iron. Professor Liversidge read two papers on it, which 

 are published in the Journals of the Royal Society of New South 

 Wales, 1872 and 1882. This example shows that Meteorites are 

 not all metal, some, indeed being true rocks like our dyke-rocks, 

 while others contain carbon. 



An interesting fact connected with the metallic Meteorites, or 

 more correctly the metallic part of some of them, is the crystal- 

 lization which is brought out by polishing a section of the 

 specimen and using acid on the surface. Of the different alloys 

 of nickel and iron which enter into the composition of these 

 Meteorites, one is more easily attacked by the acid than the other, 

 the result being the production of the figures of crystallization. 

 These can be seen in the specimens exhibited, one from Augusta 

 County, Virginia, one from Tolucca, Mexico, and another from 

 Port Duncan, Texas, the dates of their fall being unknown. 



The largest metallic Meteorite known is one over three tons in 

 weidit, which was found in Victoria, and is now in the British 

 Museum. 



Still more interesting than the above are the stony Meteorites, 

 some of which are identical with the deep rocks of our globe. 

 Most of them contain the mineral Olivine or Peridot, and belong 

 to the family of rocks called Peridotites, while some others are 

 true volcanic rocks. Intermediate between the metallic jNIeteo- 

 rites, and the stony Meteorites are some containing tlie 

 characteristics of both. 



