128 



an insoluble silicate (approaching to augite or enstatite) ;;. 

 through this paste are disseminated ' chondra ' or little spheres 

 of various sizes and consisting principally of the insoluble 

 silicate: see Wold Cottage (149 Z), Parnallee (265 N,Z). 

 Perhaps for those aerolites which contain little or no nickel- 

 iron the division into Howardites, Eukrites, Chladnites, Chas- 

 signites, Shalkites, and Carbonaceous is the most convenient. 

 The Howardites have a shiny crust, and are composed of a 

 mixture of olivine and triclinic felspar, with a little chromite 

 and nickel-iron : examples of these are Luotolax (176 W)> 

 Bialystock (205 W), Frankfort (320 W). 



The Eukrites also have a shiny crust, but contain more 

 alumina and lime and less magnesia than do the other 

 aerolites ; they consist of a mixture of augite and anorthite, 

 with a little troilite and very little nickel-iron : as examples- 

 may be cited Juvinas (190 X), Stannern (165 X), and 

 Jonzac (187 X). 



The Chladnites contain bronzite or enstatite, and occa- 

 sionally augite ; also small quantities of nickel-iron, troilite, 

 osbornite, chromite, with occasional oldhamite : examples are 

 Bishopville (233 Y) and Bustee (255 Y). 



The Ghassignites consist principally of olivine rich in iron 

 and enclosing chromite: see Chassigny (183 W) and Mane- 

 ^aum (235 W). 



The Shalkites are a small-grained mixture of olivine^ 

 enstatite and chromite : see Shalka (248 X). 



The Carbonaceous consist of olivine and enstatite, enclos- 

 ing more or less of nickel-iron, sulphur, carbon, troilite, 

 chromite and hydrocarbons. Meteorites of this class must 

 clearly have been cold on entering the atmosphere. For 

 specimens of carbonaceous meteorites see Alais (161 Y), Cold 

 Bokkeveldt (225 Y), Kaba (268 Y), and Orgueil (296 Y). 



The importance of the examination and classification of 

 meteorites with a view to a possible recognition of 'periodicity 

 of fall need only be mentioned to be appreciated : such a 

 determination is, however, rendered very difficult by the close 

 similarity of structure and composition presented by large 

 groups, such as the Chondritic. 



Attention has been already directed to the fact that 



