4(14 Prof. B. J. Chapman on some Blowpipe Reactions. 



equally well per se, Berzelius seems strangely to have over- 

 looked the coloration of the flame as produced by many sub- 

 stances under blowpipe treatment. In his work on the blow- 

 pipe, for example, he fails to notice the character in describing 

 the reactions of lepidohte, sulphate of baryta, datolite, tri- 

 phylline, and other minerals, which exhibit it most distinctly. 

 Under axinite, moreover, he has the following statement : — 

 " Turner asserts that a flame tinged green by boracic acid is 

 obtained by the aid of sulphate of ammonia (or bisulphate of 

 potash) and fluor spar." This "assertion" is true enough; 

 but all specimens of axinite colour the flame green per se. The 

 uselessness of the flux was pointed out, I find, by Buzengeiger 

 as long ago as 1829. In the Annales des Mines for that year 

 (tome v. p. 36), he states : — " J'ai essaye, pour reconnaitre la 

 presence de l'acide borique, d'employer le flux indique par 

 M. Turner, mais ces tentatives ne m'ont pas reussi, probable- 

 ment par defaut d'habitude. Quoi qu'il en soit, tous les mine- 

 raux que M. Turner a vu colorer la flamme en vert en les 

 melant avec son flux, m'ont donne la meme reaction en les 

 introduisant avec quelque soin dans la flamme bleue, sans les 

 melanger avec aucun reactif." Buzengeiger, whose name 

 does not seem to be quoted in any blowpipe work, appears to 

 have first proposed the sloping the blowpipe-wick long before 

 it was adopted by Plattner ; and he noticed, at the same early 

 date, that the crimson coloration of the strontium-flame was 

 entirely obliterated by the presence of barytic compounds. 



On the Comportment of certain Alloys under the Action of 

 the Blowpipe. — In examining these reactions, about equal 

 portions of the metals (forming the alloy) may be placed 

 together on charcoal, and subjected to the action of a reducing 

 flame. 



1. Platinum and Tin unite with violent deflagration and 

 emission of light, forming a hard, brittle, and infusible 

 globule. 



2. Platinum, Zinc and Tin unite with violent action, the 

 zinc throwing off long flakes of oxide. 



3. Platinum and Zinc, per se, do not combine, the zinc 

 burning into oxide. 



4. Platinum and Lead unite quietly, forming a brittle 

 globule. 



5. Platinum and Thallium unite quietly; the resulting 

 globule is dark externally, grey internally, and quite brittle. 



6. Platinum and Bismuth unite quietly, or with merely 

 slight spitting, into a dark brittle globule. 



