388 Intelligence and Miscellaneous Articles. 



these tilestone-beds of Shropshire and Herefordshire (which have 

 about 40 or 50 feet of thickness), Sir Roderick is inclined to regard 

 them as true " passage-beds " between the Silurian and Devonian 

 systems, and to be classed with the lower or the upper system 

 according to the prevalence of certain fossils. 



3. " On the occurrence of Mastodon Bones in Chile." By W. 

 Bollaert, Esq. Communicated by Prof. Owen, F.G.S. 



The author observed, that hitherto there have been few if any 

 fossil bones of large quadrupeds found on the western side of the Andes. 

 During his travels in South America, he had diligently searched for 

 information on the subject ; and he had learnt from Mr. G. Smith, 

 H.B.M. Consul at Santiago de Chile, that some elephantine bones 

 had been met with in digging a trench to drain the Lake Taguatagua, 

 in the province of Colchagua, about 45 leagues due south of the 

 capital, and at an elevation of 2300 feet above the level of the Pacific 

 Ocean. This lake occupied a circular and crater-like depression 

 among the third range of hills running N. and S. through Chile. 

 The skeletons of two animals were found at the depth of about 30 feet 

 below the margin of the lake. 



Some of the teeth (referred to Mastodon by Don V. Bustilos) 

 are in the Museum at Santiago, and fragments of the femur and 

 tibia brought home by Mr. Bollaert have been also referred to Mas- 

 todon by Prof. Owen. 



LIII. Intelligence and Miscellaneotis Articles. 



EXPERIMENTS ON THE ARTIFICIAL FORMATION OF THE HYDRATED 



CARBONATES OF THE EARTHS AND METALS. BY A. DAMOUR. 

 ^"^HE metallic and earthy carbonates have already been obtained 

 *■ artificially in a crystalline state by various processes. Thus when 

 a soluble salt and an alkaline carbonate are exposed to a high tem- 

 perature in a close vessel, double decomposition takes place, giving 

 origin to an insoluble and crystalline carbonate. A soluble salt may 

 also be precipitated by an alkaline bicarbonate in water supersaturated 

 with carbonic acid. This mixture, placed in an apparatus which 

 only allows the carbonic acid to escape slowly, and exposed to a 

 more or less elevated temperature, gives origin to anhydrous crystal- 

 line carbonates. These processes are due to the experiments of M. 

 Senarmont. 



The solution of an acid salt may be poured into a saturated solu- 

 tion of an alkaline bicarbonate, when the carbonic acid being in excess 

 exerts a solvent action on the carbonates, and by its slow evaporation 

 under the simple pressure of the atmosphere, allows the dissolved 

 matters to separate and crystallize. In this manner, sometimes 

 simple, sometimes double, hydrated carbonates are obtained. This 

 is the method of M. H. Deville. 



The author has undertaken a series of experiments on the direct 

 action of carbonic acid upon the earthy bases and metallic oxides. 

 The apparatus employed consists of a glass vessel in two compart- 

 ments, such as is used for the artificial preparation of Seltzer water. 

 7'he oxide or recently prepared carbonate is suspended in distilled 



