Philosophical Society of London. SOS 



Second limestone. — The most eastern basset of this rock 

 Is in Matlock high Tor. Its average thickness is about 80 

 yards. Its colour is yellowish or blueish gray. Some of its 

 beds are magnesian limestone. Its principal organic remains 

 are entrochi. It contains metallic veins of galena, calamine, 

 and, as it is said, of copper. 



First loadstone. — The first regular basset of this rock ap- 

 pears to be in Matlock high Tor. Its average thickness is 

 about 28 yards. Its general characters differ little from 

 those of the third toadstone, except that it seems disposed 

 in more regular beds or strata. 



First limestone. — The average thickness of this rock is 

 60 yards. Its usual colour is lightish gray : near the top 

 it incloses beds of swinestone interlaid with dark or striped 

 chert. The organic remains of this rock are anomiae, 

 entrochi, nautili, and other shells, together with many co- 

 ralloids. It abounds in caverns and water-swalloyvs, and 

 in numerous metallic rake veins, or long vertical rents. 

 Massive fluor (blue John) and elastic bitumen occur in this 

 rock. 



The great or limestone shale.— The average thickness of 

 this rock is about l.^O yards: its general character is that 

 of a black or dark brown shale, niclosing beds of a soft 

 yellowish sandstone, and of a dark blue limestone ; also 

 thin beds of clay, ironstone and septaria. Its organic re- 

 mains are not numerous, consisting chiefly of anomije, 

 mya;, helices, and a few vegetable impressions. 



First or millstone gr\t. — The average thickness of this 

 rock is about 140 yards. It is generally a white or yellow- 

 ish coarse-grained freestone in thick beds : but at the upper 

 part of the rock is a considerable thickness of soft mica- 

 ceous thin beds. Its organic remains are large reeds and 

 flags, and occasionally coralloids of a horn-like appearance. 



Coal formation. — This lies on the millstone grit, and 

 consists of eighteen beds of grit and of shale ; the aggre- 

 gate thickness of v/hich is 706 yards, and presents the usual 

 characters of the independent coal formation. 



PHILOSOPHICAL SOCIETY OF LONDON. 



In the course of last month the president. Dr. Lettsom, 

 delivered a lecture on Intemperate Drinking. 



Dr. Lettsom commenced by observing, that one of the 

 tarliest objects of discovery, nearly coeval with the first 

 history of man, and the knowledge of it, preserved to the 

 present time, is that of intoxication, or the improper use 



\'*i\. 4 i.Ni). 160, Jpril igl3. 17 of 



