452 Prof. Maskelyne and Dr. Lang's Miner alogical Notes. 



in 1723 on the 22nd of June, at Liboschitz and Pleskowitz; 



in 1743 — , likewise at Liboschitz; 



and 1753 on the 3rd of July, at Plan and Strkow near Tabor; 



and this, says he, is exceedingly wonderful that the stone he 

 (Stepling) has preserved from the stone/all of 1723 at Liboschitz 

 and Pleskowitz is exactly like the stones of 17 '53 from Tabor ! 



Mr. Greg wrote to ask me whether the Pleskowitz stone was 

 like that of Tabor, and whether I did not think the two stones 

 might be in fact identical. My reply was, that the two were 

 externally curiously alike, but that a closer inspection showed 

 the more rusty appearance of the surface of Pleskowitz to be ac- 

 companied by a greener tint in the ground-mass. I have since, 

 by order of the Trustees, had both stones cut and polished, and 

 microscopic sections made of them. The answer is decisive. The 

 two stones are entirely distinct, and present no point of similarity. 

 The Pleskowitz belongs rather to the granular than to the more 

 emphatically spherular varieties of chondritic stones, of which 

 latter Tabor is a characteristic illustration. It contains far less 

 iron than the latter aerolite, and the metallic grains are more 

 clustered and less evenly distributed than is the case in Tabor. 

 In Tabor, the rust-stains are dotted somewhat dendritically over 

 the whole face of a section ; in Pleskowitz they form patches 

 rather bright in colour, much seen at the outer part of the section, 

 even where the crust occurs, and far less in amount in the interior, 

 large parts of the area of which are quite free from them. The 

 proportion of meteoric pyrites to meteoric iron is rather higher 

 in the Pleskowitz stone, and it is disseminated in more minute 

 particles. This stone also contains the microscopic kind of iron 

 particles in rather greater abundance than Tabor. AVhen I add 

 that the specific gravity of Tabor is 3'693, and that of Pleskowitz 

 is 3*491, as determined with much care from specimens in every 

 respect similar, and that I know as yet, out of fifty of the most 

 important falls that I have examined in section, not one that is 

 like Pleskowitz, I think the original accuracy of Heuland's 

 description will be allowed to have been vindicated. 



19. Wiborg. 



The second of the two stones regarding the authenticity of 

 which Mr. Greg has raised doubt, though himself not connected 

 with their history, is that called in my catalogue Lontalux 

 (Loutolax or Luotalaks). 



I hope soon to obtain a specimen of the true Loutolax for 

 comparison ; but I feel convinced that the stone so named in 

 our collection cannot be correctly designated. The description 

 given by Rose of the true Loutolax, which he places in his 



