460 DR. W. FLIGHT, GREENLAND METEORITES. 



berg, supporting the view that they may possibly have been 

 erupted. 



Of the rocks composing the globe, the greater portion accessible 

 to us have been modified by the action of water. There is one 

 class of which this cannot be said : the molten masses brought to 

 the surface by volcanos, the various rocks we term " lava." How 

 ever they may differ as regards constituent minerals, they have 

 amongst them a family resemblance, and it is with them that the 

 meteoric rocks may be compared. The old lavas of Iceland and 

 Java consist of augite and anorthite, as do the meteorites of 

 Juvin»s, Jonsac, and Stannern. The " bombs " of the prehistoric 

 volcanos of the Eifel are composed of olivine, augite, bronzite, and 

 cliromite, minerals that are commonly met with in meteorites. 

 Hence arises the question : Are these masses, so similar in their 

 lithological characters to the meteorites, samples perhaps of the 

 the inner unchanged nucleus of our planet ? Does the original 

 mass of the earth differ in point of magnitude only from the frag- 

 ments which yield to its attraction ? 



The mean density of the earth is greater than that of the 

 minerals composing the rocks of the outer crust. The volcanic 

 rocks and the meteorites, which in point of chemical constitution 

 are basic, are alike denser than this crust. The presence of 

 metallic iron, a characteristic feature of meteorites, points to the 

 absence of water and free oxygen as one of the essential conditions 

 for their formation. Terrestrial rocks rarely contain iron, but it 

 is replaced by an oxidised form of iron — magnetite. Only in 

 combination with platinum is it found in the metallic state. May 

 the rocks of the interior of our globe contain this, the most im- 

 portant of all the metals, in an uncombined condition ? 



It has been pointed out by Daubree that a region like Green- 

 land, where doleritic rocks cover so wide an area, appears in a 

 marked degree to present the conditions necessary and favourable 

 for the upheaval of masses from very considerable depths. 



Another phase of the question to which he directs attention 

 should also be mentioned. It appears not improbable that the 

 basalt of Greenland, which contains more than 20 per cent, of 

 iron-oxide, may during eruption have undergone reduction such 

 as he imitated in his laboratory some years since. This theory is 

 the more admissible from the fact that in the region under con- 

 sideration, between Lat. 69° and 72°, ninnerous large beds of 

 lignite, as well as graphite, occur, especially in the Island of 

 Disko, in which Ovifak is situated. 



In a paper on the anomalous magnetic characters of iron-sesqui- 

 oxide prepared from meteoric iron, communicated in February last 

 to the French Academy, Dr. Lawrence Smith announces that the 

 investigation of this iron, on which he is at present occupied, has 

 convinced him that the Ovifak metallic masses arc of terrestrial 

 origin. 



The fact, observed by Nordenskjold and AVohler, of the evolu- 

 tion of a large amount of gas by Ovifak iron Avhen heated, led 

 these observers to the conclusion that it could never have been 



