384 Miscellaneous — JExfracting Fossils. 



being black shales or slates, and tbe latter calcareous), and tlie Bala 

 or Caradoc groups. 



The Upper Silurian, to consist of the Llandovery (Upper and 

 Lower), the Wenlock and the Ludlow groups. The whole of the 

 Llandovery group was placed in the Upper Silurian, in accordance 

 with the evidence cited by Prof. Kamsay in his memoir on North 

 Wales, along with the facts explained by the table, and which went 

 to prove that when it was to be separated entirely from the other 

 groups, as a Middle Silurian division, this was the most natural and 

 proper position. 



2. " On the Silurian Eocks of the English Lake-district," by Prof. 

 AUeyne Nicholson, M.D., D.Sc, M.A. 



In this paper the author classified the Silurian rocks of the English 

 Lake-district as follows, commencing with the lowest : 



1. The Skiddaw Slates. 



2. The Borrowdale Series, or Green Slates and Porphyries. 



3. The Coniston Limestone 'and Associated Shales. 



4. The Graptolitic Mudstones. 



5. The Coniston Flags. 



6. The Coniston Grits. 



7. The Kendal Eocks. 



Each of these members of the series was described lithologically 

 and pateontologically, and its geological position discussed, not only 

 with reference to the other beds of the district, but also to the 

 Silurians of Wales and North America. 



IMIZSCIEXjXjJ^I^riEOTJS. 



Mode ov Extracting Fossils fkom Limestone. — Most geologists 

 in the course of their studies have met with hard compact limestones, 

 which show, when broken, the profiles of fossils, but are too hard or 

 too homogeneous to admit of their obtaining any fossil out of them, 

 so that sometimes it is impossible to ascertain their age. The 

 following method may be of some use for obtaining fossils out of 

 such limestones : — Burn the limestone. Prepare a saturated solution 

 of borax (borate of soda) in hot water ; let it cool somewhat (from 

 50 to 70 degrees Celsius), and put the cooled limestone into it, 

 taking care that it continues to cool. There is then formed hydrate 

 of soda (caustic soda) and borate of lime, which is not liable to 

 alteration by the influence of air and water. One or two days, ac- 

 cording to the size of the piece of limestone, will be sufficient for the 

 chemical transformation. Take care that the solution is not too hot 

 and completely saturated, otherwise the caustic lime may be destroyed, 

 as by the action of pure water. The limestone becomes softer, looks as 

 if it were weathered, and allows the fossils to be .cut out easily. The 

 results are not so good if the limestone is more or less crystalline 

 or contains calc-spar, because it breaks up by the heat, and for this 

 reason the limestone may be also destroyed. 



Makbubg, GekmantT. a. von Koenen. 



