Dr. Walter Flight — History of Meteorites. 21 



3449; as in the Pultusk meteorite, the crust is lighter than the 

 body of the stone. A remarkable feature of the surface are the 

 numerous furrow-like depressions, some 8 mm. deep, which often 

 anastomose and radiate from the more even crown of the stone 

 towards its periphery ; they are confined to the more rounded 

 side of the stone. A newly broken surface is light grey, and ex- 

 hibits a net-work of fine black lines and veins of nickeliferous 

 iron; in one place a little gangue of metal measured 3 inches in 

 length and 0-3 to 0-5 mm. wide. This meteorite bears a great 

 resemblance, both as regards the crust and internal structure, to 

 those above alluded to, which fell at Pultusk, in Poland, on 30th 

 January, 1868. Spherules are abundant ; and other minerals 

 readily distinguishable are : olivine, magnetic pyrites, and chromite ; 

 the whole being inclosed in a " sphaerolithic " ground-mass of white 

 and grey grains. 



Nickel-iron, containing 15*3 per cent, of nickel, constitutes 3-5 

 per cent, of the stone, a less quantity than is found in the Pultusk 

 meteorites; magnetic pyrites amounting to 5*52 per cent., a larger 

 proportion than is met with in the Pultusk stones, occurs in grains, 

 some 1 to 2 mm. wide. The dark-coloured spherules, the presence 

 of which is a characteristic of chondritic meteorites, are more distinct 

 and numerous than those of the Pultusk stone : some are 2 mm. 

 wide, and are easily removed from the ground-mass. Yellowish- 

 white grains, some 1 mm. wide, are abundant, and here and there 

 are found grains of chromite, bearing octahedral faces. 



Viewed in the microscope, the mass of the stone is made up of 

 numberless small white crystalline granules, which give colour in 

 polarized light ; they are stated by Yom Eath to be unacted upon by 

 acid, and to consist essentially of a magnesium silicate, richer in 

 silica than olivine. Among other curious constituents detected by 

 the microscope are : a very small purple-red crystal bearing faces ; 

 a number of bright-yellow granules in distinct crystals ; some light- 

 yellow long prism-like forms ; and a few large granules 0*5 mm. 

 across, of a translucent red mineral, exhibiting conchoidal fracture. 

 So small a portion of the stone could be devoted to chemical exami- 

 nation that none of these substances, nor even the large spherules, 

 could be separately analyzed. The analysis of the stone furnished, 

 after the nickel-iron and magnetic pyrites have been deducted, the 

 per-centage numbers of acid and bases, the oxygen ratios of which are 

 1 : 1-448, the ratio in the Pultusk stone being 1 : 1-507. The analogy 

 in composition, in respect of each constituent, of two bodies from so 

 widely separated regions of planetary space is very striking. Yom 

 Eath expresses his belief that " the siliceous portion of this meteorite, 

 and indeed of the Pultusk stone, is mainly composed of olivine and 

 another, a magnesium, silicate richer in silicic acid ; but whether it 

 be enstatite or shepardite (2MgO,3Si0 2 ), or whether both silicates 

 accompany the olivine, cannot, unfortunately, be determined." 



Apart, however, from the doubts that are now entertained respect- 

 ing the existence of the magnesium sesquisilicate of Eose as a 

 mineral species, the analytical determinations of Yom Eath will 



