TRANSACTIONS OP THE SECTIONS. 39 



Dr. Daubeny suggested whether the more compact texture of certain calcareous 

 rocks than of others, might not be connected with the existence in them of organic 

 matter, which, by its interposition, may prevent a crystalline arrangement of its par- 

 ticles from taking place. It may be, that the attraction between the particles of 

 matter, which, if uncontrolled, would prove too powerful for the agents of decompo- 

 sition to overcome, is weakened by the presence of organic matter, which thus enables 

 the rock to supply the vegetables that take root in it with the solid matter which 

 their structure requires. To the geologist, too, it cannot but be of interest to trace 

 the several steps by which the organic matters, which primarily must have constituted 

 so large a portion of the bulk of the various extinct animals and vegetables, have 

 disappeared from the strata which enveloped them. 



On the Causes of the Irregularities of Surface which are observable in certain 

 parts of the Magnesian Limestone Formations of this Country. By Dr. 

 Daubeny. 



The magnesian limestone rock in some of the quarries near Bolsover and Worksop 

 in Derbyshire and Nottinghamshire, present a remarkable appearance. They do 

 not possess an undulating surface, as limestones generally do, but the upper and 

 under faces are covered with irregular elevations and depressions of a very marked 

 character. In many instances the spicula or indentations run all in one uniform 

 direction, and those on the under side of the block are exactly opposite to those on 

 the upper. Prof. Sedgwick had cursorily noticed the configurations which these 

 magnesian limestones possess, and ascribes them to an arrangement'of the particles 

 of the rock which took place during the act of consolidation. Dr. Daubeny, however, 

 was inclined to call in the action of atmospheric influences, and that of water im- 

 pregnated with carbonic acid, as necessary to be resorted to in order to afford a full 

 explanation of the pheenomenon ; appealing to the fact, that the exposed surfaces in 

 the quarries of this limestone, in some cases present a similar appearance from the 

 effect of weathering, and also to the circumstance, that some of the irregularities 

 seen upon the faces of the blocks seem to approach in character to those produced 

 in other limestones by these causes. 



Dr. Daubeny, in conclusion, referred to the paper he had read last year on the 

 Tyrol, in which he had attempted to explain the appearances presented by the dolo- 

 mitic rocks of that country, on principles similar to what he now suggested as ap- 

 plicable to those exhibited on the small scale in our own rocks. 



On a neio Product obtained fr,om Coal Napldha. By Mr. Leigh. 



The substance described was obtained in the course of some investigations on an 

 oil which Mr. Leigh discovered about three years and a half ago, as the result of the 

 action of a mixture of nitric and sulphuric acids on purified coal' naphtha. In their 

 behaviour with potassa, both in aqueous and alcoholic solution, the crystals now 

 brought under the notice of the section by Mr. Leigh have much analogy with the 

 oil (like that of bitter almonds) obtained at the same time with them. The oil, when 

 extensively exposed to the action of oxj'gen, becomes a crystalline solid, having much 

 the same appearance as these crystals. It is probable the crystals differ from the oil 

 in containing a quantity of oxygen. Mr. Leigh had made no analysis of these 

 compounds. 



Account of the Mineralogical and Geological Museum of the Imperial Mining 

 Department of Vienna. By Professor Haidingek. 



Professor Haidinger, in this communication, gave a detailed account of the ar- 

 rangements which had been adopted in the preparation of this celebrated museum. 

 The basis of this collection existed in the Museum of the Mining Department pre- 

 vious to the appointment of Professor Mohs. Under the presidency of Prince Au- 

 gustus Lobkowicz the Museum was considerably augmented, both by the exertions 

 of the mining department and by contributions from private collectors. The method 

 of arrangement employed in the Museum was suggested by Mohs himself, and fol- 



