390 ICFFECTS OF DROUGHTS ON DISTR I I'.UTION OF PLANTS. 



could not find a single shrub, or shrublet, or other perennial 

 which had died during the summer. 



There is no doubt that the south-east clouds wei'e the cause 

 of this difference, and just as in the more outlying districts of 

 the Cape region, eg-, on the Bokkeveld. the Zwartebcrgen, the 

 Wittebergen, etc., the lower limit of the Cape flora, as such, ex- 

 tends only as far down the mountain as the summer clouds 

 reach, so we find on the Cape Peninsula the lower limit of the 

 mountain flora at the lower level of the clouds, which, as far 

 the northern and western sides of Table Mountain are con- 

 cerned, would be about 2,000 feet above sea level. 



In the absence of exact records it is impossible to say 

 whether, through such an extreme summer, any species would 

 become actually extinct within a certain area, but that many 

 species are prevented from extending ilieir domain, or rather. 

 from retaining any new territory occupied in the years of good 

 or average rainfall, must l)e obvious from the foregoing obser- 

 vations. 



Potash in Alsace. — The scarcity of ])otash for man- 

 urial and other purposes, v hich is at present being felt all over 

 the world, is drawing forth man) suggestions for its extraction 

 from sources either discarded or disregarded. Meanwhile M. 

 Henri Blin, in the Revue Generalc dcs Sciences, describes the 

 potash dei)osits of Alsace. The beds are estimated to contain 

 3,000,000 tons of ])ure potash, almost enough for a five centuries' 

 supply at the present rate of demand. Sylvinite — which mainly 

 consists of potassium chloride — is the i)redominating mineral in 

 the Alsacian de])osits. 



Astronomical Discoveries. — According to the re- 

 port of the Council of the Royal Astronomical .'Society, submitted 

 at the 96th Annual General Meeting, 56 minor ])lanets were dis- 

 covered and five comets observed during 191 5. Oi the comets, 

 two, Winnecke's and Tempel's were returns of periodic comets 

 of the Jupiter family previously observed, the former in 1819, 

 and the latter in 1873. Two of the remaining three comets were 

 discovered by J. E. Mellish, at Madison, Wisconsin, U.S.A., 

 during February and September respectively. The fifth comet of 

 the year was discovered by C. J- Taylor, at Claremont, Caj^e 

 Province, on November 22: it was also a member of the Jupiter 

 family. 



