TRANSLATIONS AND NOTICES 



GEOLOGICAL MEMOIRS. 



Experiments on the Formation of Coal, and on the Origin of Fossil 

 Resins. By Professor Goppert. 



[Arbeiten der Schlesischen Gesellschaft in J. 1847, p. 70.] 

 Last year I directed the attention of the Society to the successful 

 results of some attempts which I had made to form coal by means 

 of moisture, the plants employed in these experiments having been 

 placed for a long time in water, to which air had access, and whose 

 temperature was maintained during the day at 80° R. (212° F.), and 

 at 50° to 60° R. (135° to 167° F.) during the night. In this manner 

 there was obtained from many plants even in one year, from others 

 only after two years, a product which in its external aspect could not 

 be distinguished from brown-coal ; but by this process even in two 

 and a half years I could not obtain a substance similar to stone-coal, 

 or a coal of a black, shining aspect. I only succeeded in obtaining 

 this by adding a small quantity of sulphate of iron, about g^th per 

 cent. ; which I did in the belief that the sulphuret of iron, so common 

 in stone-coal, has undeniably proceeded from the plants which have 

 contributed to the formation of the coal. 



In these experiments I used the following fresh plants : — 



Fronds of Polypodium effiisum, 



„ „ Pteris nemoralis, and 



„ „ Cheilanthes repens ; 

 Aspidiumfilix mas (fresh stems), 

 Wood with branches and leaves of Pinus balsamea, 

 Leaves of Chamcerops humilis, 



„ „ Cycas revoluta, 



„ „ Lycopodium denticulatum, — 



plants that may be considered as the chief representatives of the an- 

 cient flora. 



A certain quantity A, with the amount of sulphate of iron-prot- 

 oxide just mentioned (2 drachms to 6 ounces of fresh plants), and 

 another quantity B, without it, were placed each separately in a 

 peculiar, slightly shut box with water of the temperature stated 

 in the Digestorium of the laboratory of the University here, on the 

 27th of February 1846. Even in two months a striking change, an 

 incipient brownish-black colouring, was observable on the plants en- 

 closed in the first box A, whilst the others B had scarcely wholly ex- 

 changed their green colour for a faded hue ; and when I concluded 

 the experiment on the 1st of May 1847, consequently after fourteen 

 months, those in A appeared entirely black, and darker than the 



VOL, VI, — PART II. D 



