OBSERVATIONS OF LUMINOUS METEORS. 129 



and without a trace of the radiated structure. The ' breast-side ' is free 

 from all great depressions, while the others show them, due probably in 

 part to the original form of the stone, partly to the action of currents of 

 air on the melting surface. The freshly broken surface of the stone is 

 dull ash-grey in hue, darker than the Pultnsk stones, the texture finer 

 and more sharply marked than in the case of most of the chondrites. 

 We see many small dull grey or dark-coloured chondra, and splinters 

 and fragments of the same kind, many larger dull grey chondra, also 

 white small chondra and white fragments, the latter far fewer than the 

 former. Between them an ash-grey earthy matrix, and very few yellow 

 metallic lustrous particles. Most of the dark chondra are less than 

 1 mm. in diameter, those which have a diameter of 1 mm. are fewer, and 

 there are occasional chondra which exceed 1 mm. in size ; the largest one 

 had a diameter of 5 mm. 



The microscopic examination of the action of this material displayed 

 many curious features, and appears to confirm the views already expressed 

 by Professor Tschermak regarding the probable influences which have 

 taken part in the form which the chondra and other enclosures take. 



Some chondra presented an appearance which has not hitherto been 

 observed. They have round depressions, which point to a plasticity of 

 the chondra during contact, as if the spherules which form the splintered 

 fragments had acquired their form during the act of rubbing. Others 

 again have projections of a rounded form, or an almost pointed end. 

 These chondra are the result of volcanic eruptions or explosions. 



Olivine. — Both in the matrix, and in many chondra, well- developed 

 crystals of olivine were met with. They have the same crystalline form 

 as the olivine in basalt. Many of the chondra consist of individual 

 crystals. Many crystals have cavities enclosing black angular grains, or 

 a black impregnation of the crust, or black slightly translucent spherules 

 or enclosures of ' glass ' ; some exhibit a most distinct surface of the 

 enclosed material. 



Bronzite. — Barred and fibrous individuals of a brown colour are re- 

 garded as bronzite. Some of the barred chondra shown in the plate 

 accompanying the paper of Makowsky and Tschermak are very perfectly 

 developed and very curious. Some have a darker border, others a lighter 

 rim. In these chondra also the enclosed material already referred to is 

 met with. 



Enstatite. — Many of the chondra of this mineral are distinguished by 

 their marked foliated structure, and specimens of such are shown in the 

 plates. The enclosed ' glass ' is also found in them. Many spherules, 

 and fragments of spherules, of a crystallised mixture of bronzite and 

 olivine or of enstatite and olivine were noticed, none however of a 

 crystallised mixture of bronzite and enstatite, and it appears therefore 

 as if this meteoric tuff originated from two sorts of stony mixtures. 



Augite. — A few small chondra with a compact pale-coloured crust have 

 a texture and colour which differs from all the foregoing. The entire 

 spherule is shown by polarised light to be one individual ; the crust is 

 almost colourless, the interior has a brownish-green hue. Their reaction 

 with light points to their being augite. 



Magnetic Pyrites and Nickel-iron. — Magnetic pyrites occur as grains 



enclosed in the other chondra and splinters of chondra, as well as free in 



the matrix. The nickel-iron is for the most part in the form of irregular 



particles with a hackly surface in the matrix. In some of the spherules 



1879. k 



