128 Chronicles of Science. [Jan., 



Whilst we have no lack of literature on the geology of the 

 volcanic district of Auvergne — of which the exceflent works of 

 Scrope and Lecoq may he cited as conspicuous examples — there has 

 hitherto been hut little written on the miueralogical, chemical, and 

 microscopic structure of the many and varied rocks of that country. 

 It is true that a few of these rocks have been carefully described in 

 the memoirs of Kosmann and of Zirkel, but it has been left for 

 Dr. Lasaulx, of Bonn, to offer us the results of a systematic course 

 of " Petrographic Studies on the Volcanic Rocks of Auvergne."* 

 The first part only has yet appeared, and this is devoted to a 

 description of certain of the Auvergne lavas, so that we must look 

 to the continuation of the memoir for a notice of the basalts, 

 trachytes, melaphyres, and phonohtes of this interesting locality. 



10. MINING AND METALLURGY. 



Mining. 



The completed returns of the mineral produce of the United 

 Kingdom for the year 1868 have been published in the 'Mineral 

 Statistics.' The following are the results : — 



Quantities. Value. 



Tons. £ 



Coal 103,141.157 25,785,289t 



Iron Ore 10.169.231 3,196,000 



Tin Ore 13,953 770.205 



Copper Ore 157.335 642.103 



Lead Ore 95.236 1.150,763 



Zinc Ore 12.781 , 39.191 



Iron Pvrites (Sulphur Ores) 76,484 53,636 



Gold Quartz 1,191 1,000 



Arsenic 3.300 9.710 



QoBsana and Ochres 6,692 6,372 



Wolfram 9 67 



Fluor Spar 60 42 



Manganese 1.700 7,650 



Barries 14.235 8,728 



Coprolites 37,500 71,500 



Salt 1,513,840 927.227 



Clays, fine and fire 1,012,479 317,770 



Earthy Minerals, various (estimated) . . . . 650,000 



Total value of the Minerals produced in the Unittd Kingdom £33.637,558 



* Leonhard und Bronn's ' JaLrbueh/ Xo. vi., 1869, p. 641. 

 + Calculated at the actual cost of raising, before any charges for movement are 

 added. 



