OF JAMES SMITHSON. ^47 



pL^'^ofii^boT""'^""^'^ ^'^ ^'"""^ ^'^'^^^" "'^ constituent 



r^.l7^'T il *''° cliange Of quality limited to the surface; how has been 

 produced the central cavity; what has forced away the maUer which 

 occupied ,t 7 A new element has been received from^ without one whch 

 existed m the matter has been parted with in a state oT vapor! S double 



regXtTon^^rP m) "'""' "'"^^^^ ^ """^^ P^^^^"^^ thi^'spede^s'i? 



As the story of his analysis of a tear indicates, he was an 

 exceedingly nice manipulator. He was one of the very first 

 who commenced the cardinal practice of modern analytical 

 chemistry the use of delicate methods and small quantities 

 ot material. His quantitative determinations were usually 

 made with about a gramme, and his qualitative determina- 

 f !?' ^ f •" '^n' almost invisible bits. In the examination of 

 the "Kative Compound of Sulphuret of Lead and Arsenic'' 

 (binnite of Naiimann) from Upper Valois, his " trials were 

 made with particles little more than visible." On pa<Te 95 

 he says : "A very minute fragment of fluor spar is Lrened 

 by means of clay to the end of a platina wire nearly as fine 



w? u' r'V''^' '' *''^ '.'^^ ^ ^^'^ ^^^'^"^y <^ven with fluxes." 

 We have be ore noticed the neat and simple apparatus (p. 

 97) for the detection of fluorine. On page 86 a method of 

 making and usmg thm clay plates is givtn, which might 

 at the present time, be advantageously employed in blow' 

 pipe work, especially if they were made from a pure kaoline. 

 I he paper on tJie "Method of Fixing Particles on the Sap! 

 pa e (fibres of cyanite; contains repeated instances of his 

 delicacy and neatness. 



Smithson's contributions to mineralogy consists princi- 

 pal y in the discovery of several new species. Native red 

 lead was first examined by him and its having been derived 

 from galena demonstrated, lie also first obs^crved chloride 

 of potassium, in a native state from Vesuvius, lie attributed 

 Its presence in lava to sublimation. The native compound 



b nni pP Jnf'l^ "^ ^''"^ '"^ ^'^^'"^ ^« *^^^ ^^^^^bic mineral 

 binnitc (of Naumann) as is recognized by its localitv, chem- 

 ical composition, hardness and cleavage. He also described 

 a native compound ot sulphate of barium and fluoride of cal- 

 cium from I>erbyshire. Naumann (Min., 9te Aufl., p 2(jl 

 Anmerkung 3) thinks, as is correct, that this is only a mix! 

 ture and not a true species. ^ 



The crystallographical observations of Sraithson are of 



Tl Prr^fir;^"^ .1 '^'^'^"''r'^"^ P'^'^^P^ ^« ^'^ instruments. 

 They refer to the forms of electric calamine, of bournonite 

 (the compound sulphuret from Iluel Boys) and of ice The 



