320 Profs. Kersten and Ehrenberg 07i 



XXXVIII. — On a Leather-like Substance found formed upon 

 a Meadow. By Charles Kersten, Prof, of Chemistry 

 in Freiberg, Saxony, and Prof. Ehrenberg, of Berlin*. 



Inclosed I send you an interesting vegetable production, 

 having a deceptive resemblance to white dressed glove-leather, 

 and which was found by M. Lindner on a meadow above the 

 wire-factory at Schwartzenberg in the Erzgebirge. 



A green slimy substance grew on the surface of the stag- 

 nant waters in the meadow, which, the water being slowly let 

 oiF, deposited itself on the grass, dried, became quite colour- 

 less, and might then be removed in large pieces. The outside 

 of this natural production, as you will observe, resembles soft 

 dressed glove-leather, or fine paper, is shining, smooth to the 

 touch, and of the toughness of common printing-paper f. On 

 the inner side, which was in contact with the water, it has a 

 lively green colour, and one can still distinguish green leaves, 

 which have formed the leather-like pellicle. I dare say a bo- 

 tanist could still determine the species to which they belong. 



I have made the following experiments on the leather-like 

 substance, having separated it from the green inner coat. 



It catches fire very easily, burns with a wax-yellow flame, 

 leaving a pale-red rough light ash. When heated in a small 

 retort dense white fumes are evolved, an odour of burnt paper 

 is perceived, and simultaneously drops of a yellow empyreu- 

 matic oil are deposited on the neck of the retort. Somewhat 

 later, water, having a strong acid action, is given off, which 

 evaporates without leaving any residue. A light charcoal re- 

 mains in the bottom of the retort. 



Water, alcohol, aether, nitric acid and aqua regia have no 

 action on it, nothing being dissolved, nor does its texture alter 

 when heated with these re-agents. A solution of hydrate of 

 potassa dissolves it to a brown slimy fluid ; caustic ammonia 

 has at first only a slight action, but after some days it swells 

 out, becomes like wet printing paper, and is partially altered. 



If the substance is gradually heated with hydrate of potassa, 



* We are indebted for this communication, and for a specimen of the sub- 

 stance described, to the kind attention of Prof. Kersten. The original ap- 

 peared in PoggendorfF's ' Annalen/ Part I. 1839.— R. T. 



f Unsized paper. — Edit. 



