C. TJ. Shepard — Meteorite from Mexico. 1.07 



The crystals are uniformly distributed, penetrating even to 

 the center of the chrysolite globules, and are often so minute 

 as to be invisible without the aid of a glass. To effect their 

 entire separation by the magnet is wholly impossible. Neither 

 can their estimation be accomplished by the aid of acids, since 

 the chrysolite is more or less decomposed by the same action 

 that dissolves the crystals. The nearest approximation to their 

 percentage, as determined mechanically, gave it at about 7 p. c, 

 though this is probably too high, through the adhesion of the 

 pulverized chrysolite in the process of separation. 



Particles of crystalline troilite of considerable size adhere 

 occasionally to the nickeliferous iron, though on an average 

 they cannot exceed 0*5 p. c. of the stone. The treatment of 

 the metallic portion of the stone in aqua regia left undissolved 

 a few very minute black shining scales of a plumbaginous 

 nature, together with equally minute non-magnetic, dull, octa- 

 hedral crystals of chromite, which gave with borax the charac- 

 teristic chromium reaction. 



Equally difficult, as in the case of the nickeliferous iron, is 

 the determination of the proportions of the chrysolite and the 

 supposed chladnite. The nearest estimate I can make would 

 be eight of the former to one of the latter, thus presenting the 

 following approximative table for the mineralogical constitution 

 of the meteorite : 



Chrysolite 80 



Chladnite ? 10 



Nickeliferous iron 7 



Troilite ) 



Chromite >• 3 



Peroxide of iron ) 



100 

 The specific gravity as determined upon two fragments, each 

 having about one-third of its surface covered by crust, was 

 347-348. 



In conclusion, it may be observed that the shape of the 

 specimen indicated it to have belonged to a stone several 

 inches in diameter. Additional particulars relating to the 

 fall will probably be furnished hereafter, through inquiries 

 promised by Mr. Landero. 

 • Charleston, April 18, 1885. 



Addendum. 



The delay which has occurred in the publication of the 

 foregoing enables me to append thereto the very interesting 

 extract from a letter of Mr. De Landero, dated Guadalajara, 

 May 30th, 1885 : 



" Respecting the exact date of the fall, I shall sooner or later 

 be able to fix it with precision. The aerolite passed over the 



