224 Notices of Memoirs — 



It is held in tlie flame of a Bunsen lamp at a height of 5 millimetres 

 from the base for the space of one minute, and its fusibility noted, its 

 soda reaction being observed directly at the same time, and its potash- 

 reaction through cobalt-blue glass or a solution of indigo. 2. The 

 second experiment is in every respect similar to the first, except in 

 the circumstance of the chimney being placed over the Bunsen lamp, 

 and the assay held at the point of fusion (Schmelzraum) of the flame. 

 3. In the third experiment the assay is first dipped in distilled 

 water, then in powdered gypsum, and lastly placed at the same point 

 of the flame as in the second experiment. 



As the lime cannot be directly determined in the presence of soda 

 and potash, the author infers the quantity of this ingredient from the 

 degree of fusibility and the characters of the fused product of the 

 assay. By digesting the assay in hydrochloric acid, however, for 

 twenty-four hours, the lime when present passes into solution, while 

 the alkalies remain almost wholly undissolved. The author bases on 

 this property of the felspars a fourth experiment for confirming the 

 results of the other three. 



The success of this method is of course largely dependent on 

 careful manipulation, the details of which are given with great 

 minuteness in the Memoir. Proofs of the accuracy of the results 

 obtained by it are given in a series of comparisons of the numbers 

 yielded by it with those afforded by the ordinary methods of analysis 

 as applied by well-known chemists to some of the best-known species 

 and varieties of felspar. J. W. J. 



ni. — On the Causes of Glacial Epochs. [Ein Beitrag zur 

 Frage Ueber die Ursache der Eiszeiten.] By Dr. G-. 

 Pilar. (Agram, 1876.) 



FEOM a study of the phenomena presented by the whole Alpine 

 system, and from the observations of Favre in the Caucasus, 

 and our own geologists in Wales and Scotland, the author concludes 

 that we have indubitable evidence of a former general lowering of 

 the temperature, and a great extension of the glacial systems through- 

 out Europe ; and although no moraines or other indications of ice- 

 action have been observed in the Altai Mountains, he considers this 

 is merely due to the moisture from the Indian Ocean having been 

 intercepted by the higher ranges of the Himalayas. 



The author further adduces the occurrence of huge erratic blocks 

 scattered over Patagonia and the deep fiords of the South-west Coast 

 of South America, and also the physical features of New Zealand, as 

 proofs of the former extension of cold in both hemispheres. 



Dr. Pilar also alludes to the former extension through France, 

 Belgium and England of a subarctic fauna and flora in prehistoric 

 times, as evidenced by the remains of the Marmot, Eeindeer and other 

 subarctic animals in the caves of these countries. 



The author cites the abandonment in the fifteenth century of the 

 earlier Danish settlements in Greenland (founded in the tenth 

 century), also the cessation of the cultivation of rye in Iceland, and 



