126 Chronicles of Science. [Jan., 



crystallized state, bodies which instantaneous precipitations ren- 

 dered amorphous. For this purpose I first introduce two bodies 

 which react on each other in liquids of different densities, containing 

 gum, sugar, or gelatine. Then I separate them by beds or par- 

 titions of porous bodies, such as wood, unglazed porcelain, &c, or 

 by leaves of unsized paper, which in imbibing them, little by little, 

 renders the decomposition slow, and nearly always produces 

 crystallized bodies. The porous vessels allow the liquid which 

 they contain to run out very slowly, and often produce beautiful 

 crystallizations, which are found in the interior of the vessels 

 when the liquid has left them. I have thus obtained in- 

 soluble bodies in a crystallized state, and often of very perfect 

 forms, such as sulphate of barytes, sulphate of strontian, carbonate 

 of barytes, borate of barytes, chromate of barytes, magnesia, 

 sulphur, &c. This method appears to me very generally applicable. 

 I have tried to apply it to the alkaline silicates, by submitting 

 them to the action of certain acids, in porous vessels, with the hope 

 of obtaining quartz or crystallized silica, which is so common in 

 nature. Slowly decomposing, they have formed white crystalline 

 masses hard enough to scratch glass. I hoped to achieve the pro- 

 duction of real quartz, but the crystals dissolved in the alkaline 

 liquids, and they were highly hydrated. There were silicates of 

 soda, containing — silica, 68 ; soda, 5 ; water, 29. The proportions 

 of silicate and water being the same as in Si O 3 , 2 H 0. These 

 experiments confirm the provisions of our illustrous confrere, M. 

 Chevreul, who, to explain the presence of oxalate of lime in certain 

 plants, supposed that a soluble oxalate slowly traversing the coating 

 of a vegetable cell, or of a bundle of fibres, could react on a cal- 

 careous salt, found in a cavity, and give birth to crystallized oxalate 

 of linie. I believe I can say, in conclusion, that the method which 

 I have published will permit all bodies which are found crystallized 

 to be artificially reproduced, whether in the earth or in organic 

 tissues, and consequently that it will afford us much useful know- 

 ledge respecting their modes of production." 



Minerals in Spain. — Attention has again been drawn to the 

 natural phosphate of lime, which exists in many parts of Spain. 

 The deposit which is now attracting attention is one stated to have 

 been discovered by M. de Luna, near Herida, in the centre of the 

 Estreniadura. As far back as 1844, however, Dr. Daubeny, in com- 

 pany with Captain "Widdrington, explored this district. Dr. 

 Daubeny then stated the composition of this phosphorite rock to be 

 about 80 per cent, of triphosphate of lime, and 14 of fluoride of 

 calcium. From that time until now, no use has been made of this ; 

 but, probably, now that a railway is brought near he locality in 

 which it exists, it may be found commercially valuable. M. de 

 Luna has forwarded samples of this native phosphate to the Academy 



