EEPORT BY ACADEMY OF SCIENCE OP ST PBTERSBUEG. 203 



" 5. And, lastly, it appears to this Commission that the view ex- 

 pressed M. S. Saeman, * according to which, ia the interior of the 

 earth, water is continually required for the formation of minerals in 

 which it is chemicaUy combined, and from which miueral operation a 

 diminution of water must foUow, deserves consideration.'' 



At the instance of the Academy of Science of Vienna, the paper by 

 Herr Wex was brought under the attention of the Imperial Academy 

 of Science in St Petersburg, by which also a Commission was ap- 

 pointed to consider it, to supply information in regard to similar 

 phenomena in Russia, and to report. In a report submitted by the 

 Commission to a meeting of the Academy held on the 27th January 

 1876, amongst others things it is stated, in reference to what had 

 been said by the author in regard to the effect of the destruction of 

 forests on the humidity of different countries : — " To these examples 

 we may add the districts in Southern Russia, where it is well-known 

 that large forests existed about 150 or 200 years ago in the very 

 spots invaded by the steppes, the higher portions of which axe 

 perfectly arid, so that the inhabitants, to prevent their dying of 

 thirst, are obliged to live on the banks of tiny streamlets in the 

 lowest valleys. We may also make mention here of the Volga and 

 Dnieper, where the destruction of the forests, from south to north, 

 has made and is making such progress that these rivers, so indispen- 

 sable to the commercial prosperity of Russia in the middle and in the 

 lower portions of their course, now flow through regions which are 

 quite cleared of forests. There the floods reach a higher level than 

 they did formerly. And who has not heard serious complaints, 

 annually repeated, with regard to the modifications of river-courses 

 caused by these floods by changing the direction of the navigable 

 channel and hoUowing out new beds for the streams t And who does 

 not know that gorges, deprived of water in winter and dry in summer, 

 during spring, in consequence of the rapid melting of the snow on the 

 naked ateppes, become, after heavy rains, impetuous torrents, which 

 undermine their banks and cany away large portions of valuable soil t 

 Furthermore, aU the affluents of these rivers bring down masses of 

 detritus, which every year contribute to the formation of new river 

 beds. We may state it as our conviction that the injury caused at 

 present by the Volga, the Don, and the Dnieper, would be much 



* 8ur V unite des phinomenet geologiques dans le aystime da lokU. Bull, de la SocUte 

 Giologique de France. 2 Serie, t. xviii.]^. 322.. 1861. 



