Clifton College Scientific Society. 63 



MEETING, NovEMBEK 21, 1872. 

 The President in the Chair. 



The fifth meeting for the term was held in the Physical Lecture- 

 room on Thursday, November 21. Thirty-five members and 

 visitors were present. 



A donation of Clifton Minerals from the President was an- 

 nounced. 



The President then read a paper on the ' Minerals of Clifton 

 and the Neighbourhood,' exhibiting a large number of specimens. 



CLIFTON MINERALS. 



1. Coal ; near Bristol. 



2. Petroleum or Naphtha ; a compound of carbon and hydrogen ; in 

 cavities in the Carboniferous limestone ; Hotwells and Black Rock, Avon 

 section. 



3. Bitumen or Asphalt ; also a hydro-carbon ; in small quantities 

 in Carboniferous limestone ; in sparry cavities, Avon section. 



4. Casts of crystals of rock salt in mud hardened into shale ; Trias, 

 Aust. 



5. JFluor spar ; Calcium Fluoride ; rare ; only in small blue or purple 

 crystals in sparry cavities in Carboniferous limestone ; Black Rock and 

 Great Quarry, Avon section. 



6. a, Calcite ; Calcium carbonate ; large crystals in veins and joints of 

 limestone, Avon section ; in cavities in Dolomitic conglomerate on which 

 the College stands ; in geodes, Westbury and Mendip Hills ; and small 

 crystals in the Lias, Horfield. h, Stalactites at Cheddar ; stalactitic crusts, 

 forming the so-called bacon-stone, at Cheddar and the Avon section, c, 

 Rock Milk ; closely resembles chalk ; Eaglestaff's Quarry, Avon section. 

 d, Marble, some of the limestones of the Avon section ; the Cotham marble 

 or landscape-stoue is found in the Lias at Cotham and elsewhere, e, An- 

 thraconite or fetid limestone ; gives a fetid smell when struck ; probably 

 contains sulphuretted hydrogen ; Black Rock, Avon section. 



7. a, Selenite ; Calcium sulphate ; single and twin crystals at Aust 

 Cliff, b, Gypsum, alabaster and satin-stone ; New red marls, Aust and 

 Pembroke Road. 



8. Heavy Spar ; Barium sulphate ; small crystals associated with quartz 

 and hsematite, iron mine at Royal York Crescent ; variety resembling old 

 bones, Avon section, under Durdham Downs ; also found in veins in 

 Carboniferous limestone, Avon section. 



9. Celestine ; Strontium sulphate ; splendid crystals in red marls and 

 sandstone at Pyle Hill ; fine radiating variety in Dolomitic conglomerate, 

 Pembroke Road ; found also in new red marls, Ashton, and lining the 

 faults at Aust Cliff ; a soft variety, which forms an impalpable powder in 

 the hand, is found near the Pembroke Road, along the railway. 



10. Dolomite ; Calcium and Magnesium carbonate ; Dolomitic con- 

 glomerate ; not crystalline. 



11. Quartz ; Silicon Dioxide : a. Rock Crystal ; clear crystals ; Royal 

 York Crescent Iron Mine with haematite ; Upper limestone shales across 

 Suspension Bridge ; Ashton ; Winford, very fine ; geodes at Cheddar and 



