424 Prof. A. Kenngott's Microscopical Investigation of 



grain from the various labourers into the proper storehouse 

 which Nature herself condescends to point out to him. Such 

 I believe to have been done by the Belgian whose work I have 

 surveyed with so much pleasure and profit. All honour to him ! 



Highgate, N., Nov. 13, 1S69. 



XLVIII. Microscopical Investigation of thin polished Laminaofthe 

 Knyahynia Meteorite. By Professor A. Kenngott, of Zurich*. 



[With a Plate.] 



THE general tint of these lamina? is grey, spotted with yellow; 

 they are semitransparent, with the exception of some opaque 

 or dark-yellow spots. Incident light shows not unfrequently 

 minute spots of metallic lustre. The whole appears fine-grained 

 to the unassisted eye, and spheroidally grained ("oolitic," to 

 use a somewhat inadequate term) under a magnifying-power 

 of two to four. The granules are grey, some of them more 

 or less angular; the yellow tints appear only in irregular 

 spots, not being proper to any distinct component. Opaque 

 substances are irregularly interspersed, in some cases mark- 

 ing the outlines of isolated granules. The spherical granules 

 pass gradually into angular forms with rounded edges; and 

 some of them lose their rounded form under strong magni- 

 fying-powers. Rounded and distinct sections appear scarce 

 under a thirtyfold magnifying-power, which has proved the best 

 for examining the structure in its totality. 



Besides the metallic and opaque particles, two crystalline mi- 

 neral species are discernible ; one of them is colourless and trans- 

 parent, the other grey and translucent ; both are bi-refractive, 

 and show various polarization colours, not separated from each 

 other by distinct limits. Some spherules consist essentially 

 of one or the other of these minerals ; in others their outlines 

 have become indistinct. The opaque substances are subordinate, 

 nor have they any influence on the structure, being merely in- 

 terposed among the rounded or angular granules. 



The structure of the Knyahynia meteorite (the relative size 

 being left out of consideration) reminds one of the globular diorite 

 of Corsica, and may therefore be supposed to be rather the result 

 of a process of crystallization within its own substance than an 

 aggregation of separately formed corpuscles. The opaque com- 

 ponents are light-grey metallic iron, greyish-yellow magnetic 

 iron-pyrites (Haidinger's "troilite"), and a black substance. 



* From a letter to Chevalier W. de Haidingcr, read to the Imperial 

 Academy of Vienna, May 13, 1869. Translated and communicated by 

 Count Marschall, F.C.G.S, &c. 



