ReporU and Proceedings — Mineralogical Society. 331 



In conclusion, the relation of some of the structures to an eutectic 

 composition is discussed. It is not, however, easy, owing to the 

 complexity of the conditions, to come to any very definite conclusions 

 in the case of old rock-masses. 



2. " Geology of the Ashbourne and Buxton Branch of the London 

 and North-Western Eailway : Crake Low to Parsley Hayi' By 

 Henry Howe Arnold-Bemrose, Esq., M.A., F.G.S. 



The present paper is a continuation of one published in 1899, and 

 deals with the geology of the next eight miles of this railway. 

 After passing through Yoredale Shales in the second cutting 

 (No. 10), the railway enters the thick beds of Mountain Limestone, 

 in which it continues as far as Buxton. The latter rock is frequently 

 folded, and owing to this no very great thickness of limestone is 

 seen. It was not found possible to correlate the beds in the different 

 cuttings. The following cuttings are described : — (9) Crakelow 

 Farm, (10) Newton Grange, (11) Moat Low, (12) New Inns South, 

 (13) New Inns, (14) Alsop-en-le-Dale, (15) Nettly Low, (16) Cold 

 Eaton, (17) Cheapside, (Itj) Bank House, (19) Heathcote, (20) Hand 

 Dales, (21) Caskin Low, (22) Lean Low, and (23) Parsley Hay; 

 and measured sections are given of several of them, with an account 

 of the folding and other features displayed. The Newton-Grange 

 cutting shows 6 feet of tuff, probably a thin representative of the 

 140 feet seam in the Tissington cutting. The limestones are in 

 places granular, oolitic, or dolomitized, and microscopical accounts 

 are given of the several varieties, as well as of the encrinital lime- 

 stones, pellets, and pebbles in the limestones, and the calcareous tuff. 



II. — Mineralogical Society of London. 

 Mineralogical Society, June 9th. — Dr. Hugo Miiller, F.E.S., 

 President, in the chair. Mr. H. F. Collins gave an account of a 

 remarkable mass of wollastonite with associated minerals which 

 occurs at Santa Fe, State of Chiapas, Mexico. This mass of nearly 

 pure wollastonite covers an area of 400 X 160 yards, and extends to 

 a depth of more than 300 feet; it is surrounded on all sides by 

 granite, felsite, and other igneous rocks, and is separated a mile 

 from the nearest limestone. Near the outskirts of the mass occur 

 extremely large crystals of wollastonite, most of which have beert 

 partially or entirely converted into quartz or semi-opal. Here are 

 also found masses of garnet and of workable copper-ores containing 

 gold and silver. The author exhibited and described specimens of 

 wollastonite, bornite in wollastonite, bornite in chalcedony, gold- 

 bearing linnaeite, idocrase rock, and a remarkable intergrowth of 

 bornite and galena resembling graphic granite. — Professor H, A. 

 Miers gave an address, illustrated by lantern-slides, in which he 

 described the extremely interesting results which he had obtained 

 from the observation of the growth of crystals by a new method. 

 The method consists in tracing the changes of angle upon a crystal 

 during its growth by measuring it at intervals by means of a specially 

 devised inverted goniometer, without moving it from the solution 

 in which it is o-rowinsr. It was found that a octahedron of alum 



