140 MICROSCOPICAL OBJECTS IN THE POTASH SALTS. 



in which they lived were never raised to too high a standard. But in 

 the Salt Lake of Stassfurt, which is always filled with a far more 

 highly concentrated solution, the existence of animal life was impossi- 

 ble ; though, at the same time, the conditions were not unfavourable to 

 the development of vegetable life. The definition of these vegetable 

 forms is, however, still an open question. In G. C. Kindt's opinion, 

 they appear to agree best with sphagnum ; Karsten, of Berlin, is 

 inclined to class them with cycads ; Schimper, of Strasburg, with 

 oscillatora3. One thing is certain, that when the peroxide of iron 

 is heated to redness, an empyreumatic odour is given out, on which 

 Goebel lays great stress, as a property belonging to algas and 

 sponges, and which originates in the 3-2 per centage of matter, 

 mentioned at the commencement of this paper as being destructible 

 by fire. 



