140 ANNUAL RECORD OF SCIENCE AND INDUSTRY.. 



6. That when submergence, in consequence of subsidence 

 of the land, was approaching its limits in the northern lati- 

 tudes of Europe, a change of climate gradually supervened, 

 and icebergs and ice-rafts set sail from the frozen islets that 

 represented Scandinavia and Great Britain and Ireland. 



In connection with the glaciation of the northern hemi- 

 sphere, Mr. Geikie recognizes a Preglacial Period, a Glacial 

 Epoch, and a Postglacial Period, followed directly by the 

 Recent Period. The Preglacial Period is represented in 

 England by the Norwich Crag, and is characterized by re- 

 mains of the elephant and mastodon ; but Mr. Geikie finds 

 no evidence of the existence of man, as shown by the discov- 

 ery of stone implements. The Glacial Epoch is divided into 

 the Great Cycle of Glacial and Interglacial Periods, a Last 

 Interglacial Period, and a Past Glacial Period. The first 

 mentioned is characterized in Europe generally by the oc- 

 currence of traces of man in the form of paleolithic imple- 

 ments, and of remains of arctic and southern mammals. 



In the second, or Past Interglacial Period, there are also 

 river gravels and cave deposits, paleolithic implements, and 

 extinct mammalia, or species no longer indigenous to Europe, 

 These include the Elephas antiquus, the rhinoceros, etc. 



In the Last Glacial Period we have also river and cave 

 deposits, with arctic mammals the arctic mammoth, the Si- 

 berian rhinoceros and paleolithic implements. The Post- 

 glacial Period is marked by the existence of raised beaches, 

 river and cave deposits, neolithic implements, and the pas- 

 sage from the stone to the bronze and iron period ; and in 

 Denmark by the occurrence of peat, and buried trees in part, 

 and kjokken-moddings. The series is closed by the Recent 

 Period, with its well-known characteristics. Reprint from 

 Geological Magazine, vols, viii and ix. 



SYNGENITE, A NEW MINERAL. 



A new mineral has been lately described by Professor Zeph- 

 arovich, from the potash beds of the salt mines of Kalusz, in 

 Galicia. This, which has been named Syngenite, occurs in 

 cubes of sylvine, in colorless, pellucid crystals, somewhat re- 

 sembling selenite. It is very closely allied to polyhalite. 

 13 A, October 15,391. 



