162 TRANSACTIONS OF THE [AUG. 15, 



polished, it was perceptible within a short time. It collected in 

 small beads on tlie piece itself, and will undoubtedly lead to 

 a rapid disintegration unless the iron is coated with varnish or 

 some other preservative. Even small fragments have already 

 become seamed, suggesting that the fall is evidently very recent. 



Microscopic sections were prepared, and in the ground-mass of 

 metallic iron were seen clear crystals of anorthite and olivine. 

 The former are quite pellucid, with inclusions of glass having 

 fixed gas bubbles, and of many needle-shaped microlites and 

 some of larger size. The former microlites are probably enstatite, 

 while some black quadratic sections may be chromite or 

 magnetite. The twin bandings of the anorthite are quite sharp 

 and distinct. The olivine crystals have greenish, brownish 

 veins of alteration (perhaps induced by the laurencite), with in- 

 clusions of gliiss, microlites, and an abundance of black grains of 

 picotite. These grains are occasioiuiUy arranged sym- 

 metrically around the crystal as a border, outside of which 

 is usually a grayish, partly opaque mass between the crystal and 

 the metallic iron. This grayish mass is an alteration of the olivine, 

 which in many cases has taken place in the entire crystal, and 

 in others has left only a small centre of clear olivine. 



To Dr. 0. W. Huntington and Mr. J. H. Caswell the writer 

 is indebted for suggestions, and to the latter for microscopical 

 determinations. 



The President described some features of the Iowa coal fields 

 which he had observed on a recent visit. 



Eemarks were made by several members upon the preparations 

 for the New York meeting, in August, of the American Asso- 

 ciationfor the Advancement of Science. 



August 15, 1887. 



Special Business Meeting. 



Meeting called by the Council, under order of the meeting 

 June 6th, 1887, for the purpose of giving welcome to the 

 Americaii Association for the Advancement of Science. 



