292 



Mineralogy. — ^^On Lite pseuclometeorite of L/ast in Livonia". 

 By Prof. Dr. A. WlCHMA^N. 



In the afternoon of the 17^'' of May 1855 at abont 6 o'clock a 

 lady, Miss Beckmanx, standing on the stairs outside a country-seat 

 2 miles N.E. from Walk in Livonia, suddenly saw between the 

 lime-trees on that spot a dazzling luminiferous phenomenon, at about 

 6 or y feet above the ground, whilst she heard at the same time a 

 tremendous clap. 



At about the same time the proprietor, Mr. Fr. Schultz, found 

 himself in a rather high field situated at a distance of 1 w^erst 

 (1.067 km.) from the country-seat. He, likewise, heard in an entirely 

 cloudless sky a violent detonation, so strong that his saddle-horse 

 and another horse, drawing a harrow, were frightened and threatened 

 to bolt. 



Assuming, on correct grounds, that a falling meteorite had exploded, 

 the chemist L. Bornwasskr immediately" made an investigation on 

 the ground in the neighbourhood of the above-mentioned lime-trees, 

 and collected two handfuls of peculiar mineral fragments which he 

 supposed to proceed from that meteorite. 



C. Grewingk, to whom we are indebted for the report concerning 

 this event, described those pieces as cellular melted masses of a 

 slaggy nature, looking much like pumiceous lava. On some fragments 

 he found moreover numerous [)articles of quartz and feldspar as 

 it were fused together with them. From the analysis made by 

 C. Schmidt appeared the enormously high percentage of 80,874 SiO* 

 of that so-called meteorite ^). He could not identify the mass with 

 any other earthly rock, and — on good grounds — rejects the 

 possibility of a formation by lightning (fulgurites). 



In 1881 F. J. WiiK made a microscopic examination of the 

 "meteorite" of Igast. He found larger individuals of quartz, orthoclase ^) 

 and plagioclase, a fine-grained groundmass, and moreover little 

 colourless, allongated crystals with globulites which he regarded as 

 ammonium chloride^). At last he pointed out that, for a meteorite, 

 the mineralogical composition was quite peculiar *). 



1) G. Grewingk und G. Schmidt, Ueber die Meteoritenfalle von Pillistfer, 

 Buschhof und Igast in Liv- und Kurland. Archiv fur dia Naturkunde Livlands, 

 Ehstlands und Kurlands, III. Dorpat 1S64, p.p. 457—461, 482—483. 



-) Read mikrokline. 



^) Hereby were meant the plagioelase-lathes. Aminoniumchloride is not exiant 

 at all 



^) Mineialogiska mcddelanden Vll. Ofversigt af Finska Vetensk. Ac. Füili 21, 

 18S1-82. Helingfors 1882, p. G3. 



