Dr. Walter Flight— On Meteorites. 313 



The microscopic examination of sections of this meteorite dis- 

 played 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 in closures 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 rub- 

 bing. Others again have projections of a i-ounded form, or an almost 

 pointed end. These chondra are the result of volcanic eruptions or 

 explosion. 



Oliiine. — 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 indi- 

 vidual crystals. Many crystals have cavities inclosing black angular 

 grains, or a black impregnation of the crust, or black slightly trans- 

 lucent spherules or inclosures of " glass " ; some exhibit a most dis- 

 tinct surface of the inclosed material. 



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

 regarded 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 inclosed 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 plate. Enclosed " glass " is also found in them. Many 

 spherules, and fragments of spherules, of a crystallized mixture of 

 bronzite and olivine or of enstatite and olivine, were noticed, none 

 however of a crystallized 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 polarized 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 

 inclosed 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 both magnetic pyrites and nickel-iron have a distinct 

 concentric arrangement. 



The stone of Tieschitz belongs to that division of the chondritic 

 meteorites which Tschermak some years since classified as remark- 

 able for "many brown finely fibrous chondra." The specific gravity 

 of the stone is 3'59. It contains about 85"0 per cent, of non-metallic 

 minerals. No trace of any mineral resembling a felspar could be 

 detected. The per-centage composition of the stone was as follows : — 



