47 



compounds of selenium and vanadium : by M. Dauber, on the de- 

 termination of crystallographic constants, and the limits of their 

 errors: by M. Schrauf, on the form of Smithsonite ; and by M. 

 Tschermak, on the secondary formation of minerals in the Green- 

 stone of Neutitschein. 



Major v. Sonklar is the author of a paper on the diminution of 

 temperature at different heights, in different seasons of the year, in 

 the Eastern Alps. 



M. Kreil has determined the magnetic constants and geographical 

 position of numerous points in the South-east of Europe, and some 

 places on the coast of Asia. 



M. Karl Friesach has continued the publication of his Magnetic 

 and Astronomical Observations in North and South America. 



M. Simon Spitzer has written a series of papers on the integra- 

 tion of linear differential equations. 



MM. Helmholtz and v. Piotrowski are the authors of a memoir 

 on the friction of incompressible fluids. 



M. Karl Fritsch has written several memoirs on Meteorology. 

 One of these is on the disturbances of the daily range of the most 

 important meteorological elements on days in which thunder-storms 

 occur. The daily range of atmospheric pressure, temperature, press- 

 ure of vapour contained in the atmosphere, from hour to hour, in 

 different months, are known already for various stations. These, 

 however, hold only for a mean condition of the atmosphere. In days 

 on which thunder-storms occur, the range of each of the meteoro- 

 logical elements exhibits a peculiar character impressed upon it in 

 the course of the preceding night, and morning; and, as thunder- 

 storms usually occur in the afternoon and evening, the approach of 

 a thunder-storm, or of the gale of wind by which it is not unfre- 

 quently accompanied, may in most cases be predicted. Another 

 gives an account of the phrenological observations made in the 

 Austrian Empire in the course of the year 1858. This contains a 

 comparison of the times of blossoming of seventy-three species of 

 plants, at fifty-nine different stations, with the times of blossoming 

 of the same plants at Vienna. On an average of the whole year, 

 vegetation is earliest at Villa Carlotta on the lake of Como, 1 20 

 toises above the level of the sea, being fourteen days in advance of 

 Vienna ; and latest at Gurgl in the Oetzthal, 9C6 toises above the 



