412 Mr» Smilhson on a Method of [Dec, 



Article III. 



A Method, ofjixing Particles oti the Sappare, 

 By James Smithson, Esq. FRS. 



(To the Editor of the Annals of Philosophy/.) 



SIR, Oct. 24, 1823. 



When the species of minerals are ascertained by their physi- 

 cal quaUties, they mostly undergo no injury, or but a very slight 

 one ; as that attending the determination of their hardness, the 

 colour of their powder, their taste, &c. This is certainly a 

 material advantage, and would highly recommend this method, 

 was it constantly adequate to its purpose. That it is not so, 

 however, we have a proof in the great errors into which have 

 fallen those best skilled in it. Mr. Werner, its principal and 

 most distinguished professor, was unable by its means to disco- 

 ver the identity of the jargon and the hyacinth ; of the corundum 

 and the sapphire ; of his apatite and his spargelstein ; and while 

 he thus parted beings, as it were, from themselves, he forced 

 others together which had nothing in common. 



The chemical method justly boasts its certainty ; but it carries 

 destruction with it, and often bestows the knowledge of an object 

 only at the expense of its existence. The sole remedy which 

 can be opposed to this defect is to reduce the scale of operat- 

 ing ; and thus render the sacrifice which must be made as small 

 as it is possible. 



M. de Saussure's* ingenious contrivance for subjecting the 

 most minute portions of matters to fire, by fixing them on a 

 splinter of sappare, appeared to fulfil the conditions of this pro- 

 blem, and to have accomplished all that could be desired. It 

 has, however, been scarcely at all employed, owing to the exces- 

 sive difliculty in general of making the particles adhere ; and in 

 consequence the almost unpossessed degree of patience required 

 for, and time consumed by, nearly interminable failures. 



That such should be the case could not but be a subject of 

 much regret, for besides economy of matter, of time, of labour, 

 and the great beauty of deriving knowledge from so diminutive a 

 source, and attaining important results with such feeble agents ; 

 reduction of volume became, in this instance, productive of 

 increase of power, and thence, of an extension of the series of 

 qualities by which substances are characterised. 



A slight alteration which I have made in M. de Saussure's 

 process has removed the objection to it. To water, saliva, 

 gum water, which he employed, the last of which is not sensibly 



• Journal de Physique, par Rozier, tome 45. 



