538 Intelligence arid Miscellaneous Articles. 



logy," read to the meeting of the British Association at Oxford in 

 1832, and published in the first volume of the Reports of the Asso- 

 ciation. 



"The discovery of artificial crystals in the slags of furnaces was 

 not unimportant to the chemistry of mineralogy. One of the first 

 and most extraordinary instances was the detection of perfect cry- 

 stals of titanium in the Welsh iron slag, by Dr. Wollaston and Pro- 

 fessor Buckland*. It has appeared by examination that these acci- 

 dental products are more free from any admixture of iron than it 

 is easy to obtain titanium by the ordinary chemical processes. In 

 1825 Mitscherlich found in the Swedish furnaces bisilicate of iron 

 (pyroxene,) mica, and other mineral species. About the same 

 time, Berthier in France obtained in the furnace, by direct syn- 

 thesis, regulated by the atomic theory, crystals similar to those 

 found in nature. Professor Miller of Cambridge has examined se- 

 veral slags from the furnaces in Wales, and it appears that the 

 crystals in those assume the form of olivine. It is satisfactory thus to 

 find that the same substances affect the same crystalline form in our 

 furnaces and laboratories, and in the great laboratory of nature. In- 

 deed nothing can be more likely to help us in obtaining a know- 

 ledge of the chemical laws of crystalline forms, than to have the 

 power of verifying our conclusions synthetically by forming cry- 

 stals, as well as analytically by destroying them." 



" In the same point of view, the examination of crystals formed 

 from solutions is of great value to mineralogy ; as, for instance, 

 the many excellent measures of artificial salts by Mr. Brooke, Mr. 

 Haidinger, and others. Such crystals may often be obtained in 

 much greater abundance and perfection than natural crystals, and 

 especially than natural crystals of similar chemical composition; 

 and thus they widen very much the field of facts to which our in- 

 quiries lead. In former times the mineralogist was professedly re- 

 stricted to substances which occur in nature ; but we may venture 

 to say that a line so arbitrary and accidental cannot be the true 

 boundary of the science. Wherever crystalline forces act, the crystal - 

 lographer is called upon to pursue his speculations; these speculations 

 whether we call them mineralogical or not, are such as give interest 

 and promise to our study. In this point of view mineralogy possesses 

 not only the importance which belongs to its ancient subjects, but 

 also an importance of another kind, which belongs to it as a neces- 

 sary supplement to chemistry j for it takes into consideration those 

 physical characters of chemical compounds (crystallization, specific 

 gravity, hardness, fracture, lustre), which belong to them as solid 

 bodies, and which indicate the law and intensity of the corpuscular 

 forces by which each combination is bound together. The study 

 of artificial crystals, therefore, whether obtained in the wet or in 

 the dry way, may be recommended as very useful to the minera- 

 logist." 



" Haldat {An7i. de Cliim. Jan. 1831,) has shown a mode of ob- 

 taining artificial crystals of iron oxide by the decomposition of 



• [* Dr. Wollaston's papers on this subject were reprinted from the Phil. 

 Truns. in Phil. Mag., First Series, vol. Ixii. p. 18, vol. Ixiii. p. 15.] 



