J, W. Evans — Apparatus for Isolating Minerals. 67 



aided subsequently by an extensive denudation, that tbe older rocks 

 of that chain are visible." ^ The Pentland faults have thus played 

 an important part in the past history of the district. But their 

 work is not yet finished, and the occurrence of the Edinburgh 

 earthquake shows that the process of geological change is still being 

 carried out on the same lines as before. It remains for future earth- 

 quakes to enable us to determine the laws which govern these 

 changes and the rate at which they are now taking place. 



Authorities. — "Dalkeith Advertiser," Jan. 24; " Dumfermline 

 Journal," Jan. 26; "Falkirk Herald," Jan. 19; "Lanarkshire 

 Examiner," Jan. 26 ; " Peeblesshire Advertiser," Jan. 26 ; 

 "Scotsman" (Edinburgh), Jan. 19, 21, 22, 23, 25, and Dec. 28; 

 "West Lothian Courier" (Bathgate), Jan. 19 and 26.'- 



For other information contained in the above account, I have 

 pleasure in thanking the following gentlemen : Mr. J, Aitken, F.E.S., 

 Prof. E. Copeland, F.R.S.E., Dr. G. Craigie (Musselburgh), Mr. W. 

 Dick (Tynehead Station), Dr. John Doig (Bathgate), Prof. J. Geikie, 

 F.R.S., Dr. C. B. Gunn (Peebles), and the Rev. W. Ross (Polmont) . 



{To be continued.) 



111. — An Inexpensive Apparatus for the Isolation of Minerals 

 BY Means of Heavy Liquids.^ 



By J. W. Evans, LL.B., B.Sc, F.G.S. ; 

 Demonstrator in Geology, Royal College of Science, London. 



I AM aware that in describing a new apparatus for separation 

 by heavy liquids, I am adding another item to a list which is 

 already a very long one. My only excuse is that this particular 

 form has the advantage of being easily and cheaply constructed from 

 ordinary chemical apparatus, and yet has most of the advantages of 

 Thoulet's* comparatively expensive form. 



The construction and use will be best explained by means of the 

 accompanying drawings. 



i4 is a cylindrical funnel. The conical portion connecting the 

 upper cylinder with the narrower cylinder or tube below, should be 

 as steep as possible, otherwise a little trouble is .occasioned by par- 

 ticles adhering there. 



The funnel is closed below by means of a piece of india-rubber 

 tubing and pinchcock. It may be supported on an ordinary wooden 

 filter stand. 



1 Geol. of the Neighbourhood of Edinburgh, p. 120. 



^ The following papers contain descriptions of the Edinburgh earthquake : — A. G., 

 The Earthquake at Edinburgh, Nature (Jan. 31, 1889), vol. 39, pp. 324-325. E. 

 Richardson, On the Earthquake Shocks experienced in the Edinburgh District on 

 Friday, January 18, 1889 (read before the Edinburgh Geol. Soc. on Feb. 21, 1889), 

 " Scottish Geographical Magazine " for March, 1889. 



^ A short notice of my apparatus in its simplest form will be found at p. 108 of 

 the interesting and valuable Manual by Professor Cole, of the Royal College of 

 Science, Dublin, entitled, " Aids to Practical Geology," which has just been 

 published. 



* Bull. Soc. Min. de France, t. ii. (1879) p. 17. 



