78 REPORT 1859. 



fragments of peat, on which it lies, and recent shells, Cardium, Mya, Mactra, &c, in 

 a fossil state. 



It is a curious fact that the well-known Fontainebleau sandstone which presents 

 the rhombic crystals of calc-spar, having been recently analysed by my friend M. Pisani, 

 gives likewise 63 per cent, of sand and 30 per cent, of carbonate of lime *. 



I would also notice here, that a rock very similar in appearance to the one men- 

 tioned in this note, is preserved in the mineralogical collection of the Jardin des Plantes 

 of Paris. It is called " Gres de Beauchamp " (Seine et Oise) ; it contains both marine 

 and freshwater fossils, and has in every respect the same external appearance as the 

 rock discovered by me on the coast of Flanders. 



On Soluble Silicates, and some of their Applications. 

 By Frederick Ransome. 

 The writer gave a history of the discovery of the soluble silicates, and of the various 

 researches and experiments of Dr. Fuchs of Munich, and of Professor Kulman of 

 Lille, and of the several applications of these silicates of Steriochony, to the various 

 branches of manufacture, and to the effects of their combinations with lime, whether 

 carbonate, sulphate, phosphate, or caustic ; but described more in detail the value of 

 their applications in the manufacture of artificial stone, and in the preservation of 

 natural stone, &c. from decay. In the manufacture of artificial stone, he stated that 

 the soluble silicate of soda or potash was mixed with siliceous sand and other similar 

 materials, and after being thoroughly incorporated together, the mixture was forced 

 into suitable moulds, and afterwards burnt in a kiln, by which operation the soluble 

 silicate combined with an additional quantity of silica, which was supplied by the sand, 

 &c. with which it was incorporated, and became converted into an insoluble glass, 

 firmly agglutinating all the various particles together into a solid, compact substance, 

 in all respects resembling the finest qualities of natural sandstones. Mr. Ransome 

 produced some specimens of his manufactured stone to the meeting, showing that the 

 material was capable of receiving the most delicate impressions from the most elaborate 

 designs, and that, unlike all other plantic materials which are subjected to a red heat, 

 it retains all its sharpness of outline, and is not liable to contraction or distortion in 

 the process of manufacture. He also gave an account of an interesting series of 

 experiments recently conducted in the testing-house of Her Majesty's Dockyard at 

 Woolwich, for the purpose of ascertaining the relative properties of his artificial stone, 

 as compared with the natural stones usually employed in the construction of buildings ; 

 and showed that its power of resistance to steady transverse strain was represented 

 by 100, whilst that of 



Darley Dale stone was 81 



Of Gumshill stone was 37 



Of Portland stone was 33 



Of Aubigny stone was 31 



Of Bath stone was 13 



Of Caen stone was 12 



At the same time, a block of this material, 2-inch cube, sustained a weight of 21 

 tons; whilst a similar block of Darley Dale stone sustained only 1G£ tons — thus 

 illustrating its suitability for purposes of construction. In the application of soluble 

 silicates to the preservation of natural stones, &c, Mr. Ransome explained the details 

 of his process, which consists not merely in the application of a soluble silicate, as 

 described and adopted by Professor Kuhlmann and others on the Continent, and 

 which Mr. Ransome stated he found to be utterly ineffective in this country, being 

 liable to removal by rain, or even by the humidity of the atmosphere; but consisted, 

 first, in treating the stone, &c. with a solution of silicate of potash or soda, and 

 afterwards with a solution of chloride of calcium, or chloride of magnesia ; by which 

 means a double silicate, or silicate of lime, or silicate of magnesia, was immediately 

 formed in the pores and structures of the stone, &c, — which double silicate possessed 



* It appears evident from these facts, that, in nature, 30 parts of carbonate of lime are 

 sufficient to fix or agglutinate twice their weight of sand, &c. This is doubtless effected by 

 a process of slow crystallization. 



