On the use of the Blow-pipe. 109 



Notes on some new Supports for Minerals subjected to the 

 action of the common Blow-pipe. By Lieut. Col. J. G. 

 Totten. Read April 26, 1824. 



James Smithson, Esq., in a letter to the editor of the 

 Annals of Philosophy, on the subject of securing small parti- 

 cles for examination by the blow-pipe ;* communicates several 

 ingenious modifications of Saussure's process with splinters of 

 sappare, which process he observes, " has been scarcely at all 

 employed ; owing partly to the excessive difficulty, in general, 

 of making the particles adhere, and in consequence of the 

 almost unpossessed degree of patience required, and of the 

 time consumed by nearly interminable failures." Mr. Smith- 

 son's processes are three. 1st. Small plates of clay " are 

 formed by extending a white refractory clay, by blows v. t' 

 the hammer, between the folds of a piece of paper, like go id 

 between skins. The clay and paper are then cut together 

 with scissors," •' into very acute triangles," affording a sub- 

 stitute for Saussure's sappare. 2d. Or a very little of the 

 moist clay may be taken up on the end of a pointed platina, 

 or other wire ; and the object to be tried, being touched with 

 it, will adhere. 3d. Or a paste may be made of some of the 

 body itself, reduced to fine powder. With a paste of the 

 powder of flint and water, " pieces of flint were successively 

 connected to flint ; and some of this paste taken up on the 

 end of a wire, served, if not quite as well as clay, yet very 

 sufficiently." 



Pursuing the advantage gained by these improvements, 

 Mr. Smithson made several interesting experiments ; and, 

 among the rest, found, " with much surprise, that flint can 



* Reference is made to this letter for many interesting details. See 

 No. 36 of the new series of those Annals : or No. 25 of the Technical 

 Repository. 



