Br. C. Le Neve Foster — What is a Mineral Vein or Lode ? 513 



issued in 1880, and that contains eighteen beautiful lithographic plates 

 of fossils from the Oolites, with descriptions of several new species. 



The map accompanying this volume has been executed by Mr. 

 Stanfoi'd with his unrivalled clearness and excellence of style, though 

 perhaps the faults are marked a little too clearly. The geology is 

 reduced from the Geological Survey Map constructed by Mr. Bristow^ 

 and takes in the whole of the country from Swanage to Bridport 

 Harbour. 



With this volume and its supplement the student will find himself 

 well able to master the geology of this interesting and picturesque 

 district ; for Mr. Damon furnishes many miscellaneous geological 

 notes and also gives references to papers where further details may 

 be found, while his memoranda on the Natural History and the 

 Antiquities of the county will lend much additional charm to its 

 study, and perhaps stimulate enquiry into other branches of science 

 besides geology. 



Abstracts of Papers read before the Geological Section of 

 THE British Association at Montreal, August, 1884:. 



{Continued from the October Number, p. 478.) 



13. — What is a Mineral Vein or Lode ? 



By C. Le Neve Foster, B.A., D.Sc, F.G.S., H.M. Inspector of Mines. 



THE author quoted briefly the definitions of a mineral vein given 

 by Werner, Carne, Von Gotta, Grimm, Von Groddeck, Geikie, 

 Sandberger, and Serlo, who, in common with most geologists, have 

 looked upon mineral veins as ' the contents of fissures.' While 

 admitting that a very large number of veins may be so described, 

 the author contended that the exceptions are sufficiently important 

 and numerous to warrant a change in the definition. He is of 

 opinion that many of the principal and most productive tin-lodes in 

 Cornwall are simply tabular masses of altered granite adjacent to 

 fissures ; and he brought forward the opinions of other geologists to 

 show that certain veins in the English Lake district, the Tyrol, Nova 

 Scotia, Nevada, Colorado, California, and Australia are not fiUed-up 

 fissures. In conclusion, he proposed the following definition : ' A 

 mineral vein or lode is a tabular mineral mass formed, more or less 

 entirely, subsequently to the enclosing rocks.' 



14. — On Ice-age Theories. 

 By the Eev. E. Hill, M.A., F.G.S., Tutor of St. John's College, Cambridge. 



ON the Montreal Mountain, in the neighbouring quarries, at the 

 mouth of the Saguenay River, and more or less everywhere 

 over all Canada and all the north and north-west of this continent, 

 are seen phenonema which imply a former vastly extended action of 

 ice. The like are found over Europe and Asia, thus completely 

 encircling the pole. Many theories have been propounded to account 

 for these facts. It is proposed to pass these before you in review. 



DECADE III. VOL. I. — NO. XI. 33 



