400 
ARTICLE XX. 
Remarks on the real Occurrence of Fossil Infusoria, and their 
extensive Diffusion; by Prof. KHRENBERG. 
From J.C. Poggendorff’s Annalen der Physik und Chemie, vol. xxxviii. No. 5, 
p- 213 *; with a Plate. 
In the month of April of this year I communicated to the Academy + 
a remarkable fact relative to the infusoria of the mineral springs of 
Carlsbad, namely that they appeared to be the same species as those 
met with on the French coasts of the Atlantic and in the Baltic. For 
the knowledge of this fact I was indebted to the kindness of the pro- 
prietor of the porcelain manufactory in Pirkenhammer, near Carls- 
bad, M. Fischer, who, at my request, brought for me to Berlin some 
of the water containing living animalcules. In order to follow up the 
examination more closely and more extensively, I requested another 
supply, which I received a fortnight ago in good condition. At the 
same time M. Fischer informed me, in a letter dated 20th June, that 
he himself had made a curious observation. He had remarked that the 
Kieselguhr{ (announced by M. Radig in the Jahrbiicher fir Deutsch- 
lands Heilquellen, &c., edited by MM. von Grefe and Dr. Kalisch, 
1836, p.193.), which occurs in the peat-bog of Franzensbad, near Eger 
in Bohemia, consists almost entirely of the shields of Navicule, and ap- 
pears to owe its origin to the action of volcanic heat on the bottom of 
the sea. M. Fischer sent me, together with this information, a piece of 
this fossil siliceous body, originally rather more than 2 inches long, 
1 inch broad, and 3 inch high, which I have presented to the Royal 
Mineralogical Cabinet; he requested me at the same to determine 
the forms of the animalculz, and to publish his observations together 
with my results. Microscopical examination directly confirmed the 
observation of M. Fischer, that the Kieselguhr of Franzensbad con- 
sisted almost entirely of Navicule ; and the great transparency and clear- 
* This paper was read in the Royal Academy of Sciences of Berlin on the 
7th July, 1836. [The translation is by Mr. W. Francts. ] 
+ Compare the Report of the Proceedings of the Royal Academy of Berlin, 
1836, pp. 36, 50, and 55; and Wiegmann’s Archiv. for Nat. Hist. 1836, p. 240. 
t [A kind of siliceous paste ; from Kiesel, stlex, and Guhr, a term used in mine * 
ing for water carrying dissolved minerals when in a thick liquid state —W. F.] 
