378 Geological Society. 



such abundance, under favourable circumstances, that the difficulty 

 disappears. In the Public Garden at Berlin he found that workmen 

 were employed for several days in removing in wheelbarrows masses 

 which consisted entirely of fossil Infusoria. He produced from the 

 living animals, in masses so large as to be expressed in pounds, tri- 

 poli and polishing slate similar to the rocks ironi which he had ori- 

 ginally obtained the remains of such animals ; and he declares that 

 a small rise in the price of tripoli would make it worth while to 

 manufacture it from the living animals as an article of commerce. 

 These results are only curious ; but his speculations, founded upon 

 these and similar facts, with respect to the formation of such rocks, 

 for example, polishing slate, the siliceous paste called keiselguhr, and 

 the layers of flint in chalk, are replete with geological instruction. 



As the discoveries of Prof. Ehrenberg are thus full of interest for 

 the geological speculator, so have they been the result, not of any 

 fortunate chance, but of great attainments, knowledge, and labour. 

 The author of them had made that most obscure and difficult portion 

 of natural history, the infusorial animals, his study for many years ; 

 had travelled to the shores of the Mediterranean and the Red Sea 

 in order to observe them ; and had published (in conjunction Avith 

 Prof. Miiller) a work far eclipsing anything which had previously 

 appeared upon the subject. It was in consequence of his being 

 thus prepared, that when his attention was called to the subject of 

 fossil Infusoria, (which was done in June, 1836, by M. Fischer) he 

 was able to produce, not loose analogies and insecure conjectures, 

 but a clear determination of many species, many of them already 

 familiar to him, although hardly ever seen perhaps by any other eye. 

 The animals (for he has proved them to be animals, and not, as others 

 had deemed them, plants) consist, in the greater number of examples, 

 of a stafl-like siliceous case, with a number of transverse markings ; 

 and these cases appear in many instances to make up vast masses by 

 mere accumulation without any change. Whole rocks are composed 

 of these minute cuirasses of crystal heaped together. Prof. Ehren- 

 berg himself has examined the microscopic products of fifteen locali- 

 ties, and is still employed in extending his researches; and we already 

 see researches of the same kind undertaken by others, to such an 

 extent, as to show us that this new path of investigation will exercise 

 a powerful influence upon the pursuits of geologists. We are sure 

 therefore that Ave have acted in a manner suitable to the wishes 

 of the honoured Donor of the medal, and to the interests of the 

 science which we all in common seek to promote, in assigning the 

 WoUaston medal to Prof. Ehrenberg for these discoveries. 



Although it is not necessary as a ground for this adjudication, it 

 is only justice to Prof. Ehrenberg to remark, that his services to 

 geology are not confined to the researches which I have mentioned. 

 His observations, made in the Red Sea, upon the growth of corals, 

 are of great value and interest; and he was one of the distinguished 

 band of scientific explorers who accompanied Baron von Humboldt 

 in his expedition to the Ural Mountains. And I may further add, 

 that even since the Council adjudged this medal. Prof. Ehrenberg 



