KARSTEN ON THE GYPSVM AT LUNEBURG, ETC. 19 



Araucarites carbonariuSy is in a remarkable degree more rarely met 

 with here than in any other coal with which I am acquainted. The 

 short time left me was occupied with an excursion to Belgium, where 

 at Liege I examined the coal-mines sitiiated in the town itself (houil- 

 leres de Bellevue a St. Laurent), where I found exactly similar con- 

 ditions, beautiful Lepidodendra, as in the Wellesweiler mine. 



On my journey home I visited some mines in Westphalia, near 

 Essen, under the friendly guidance of Herr Heintzmann, Councillor 

 of Mines ; all of which showed in the coal, along with multitudes of 

 Stigmarise, also Sigillarise and Lepidodendra in more or less abun- 

 dance. 



When w^e now reflect, that in every carboniferous deposit which 

 I have had an opportunity of examining, I have found the coal, not 

 as has hitherto been universally assumed, and as Elie de Beaumont 

 has recently maintained in his Lectures on Geology, a more or less 

 uniform mass, showing no trace of vegetation, but that I have dis- 

 tinctly recognized, even with the unaided eye, the plants that have 

 contributed to its formation ; — it becomes more than probable that 

 the same thing would be found everywhere, if these conditions and 

 the way and manner in which I make my observations w^re only at- 

 tended to. Differences will no doubt always appear, since the more 

 or less perfect preservation of the structure depends, among other con- 

 ditions, very much on the degree of decomposition to which the vege- 

 tables had already attained, before they were protected from any 

 further waste or decay, by being buried between layers of earth and 

 stone, which cut ofP all access of the air. The vegetables, for ex- 

 ample, which are found buried in the coal-basin on the Worm, had 

 made further progress towards decay than usual, and hence the rarity 

 of specimens in which the structure is well-preserved. 



[J. N.] 



On the Relations of the Gypsum at Luneburg, Segeberg, and 

 LiJBTHEEN. By C. J. B. Karsten. 



[From Monatsbericht der Akademie der Wissensch. zu Berlin, 1848, p. 130.] 



The masses of gypsum at the localities just mentioned are anhydrite, 

 which has been partially converted into gypsum in its original situa- 

 tion. The plutonic formation of the anhydrite is proved by its rela- 

 tion to the stratified rocks, which, in consequence of the elevation t>f 

 the anhydrite, have also been brought nearer to the surface of the 

 earth. It is also confirmed by the character of the matter with which 

 the fissures in the gypsum are filled. This matter shows in all the 

 three localities the same relations and the same chemical composition. 

 It consists of a crystalline, sometimes compact, sometimes gra u lar, 

 sometimes slaty, bituminous mixture of finely pulverized silicate of 

 alumina, of carbonate of lime and carbonate of magnesia, in very different 

 proportions. These combinations of the carbonates are very distinct 

 from the composition of the dolomite from which they may have origi- 

 nally been produced. The muschelkalk, which at Luneburg is raised 



