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XXXII. 



A REFINED METHOD OF OBTAINING SUBLIMATES. 



By ARNOLD L. FLETCHER, M.A., B.E., 



Research Assistant to the Professor of Geology and Mineralogy in 



the University of Dublin. 



[Read Notemher 26, 1912. Published February 17, 1913.] 



The facilities presented by the meldometer in the investigation of minerals 

 by means of their sublimates and in general pyro-chemistry were pointed 

 out by Professor Joly in 1891,^ and more recently reference has been made 

 to the volatile deposits yielded by certain minerals at high temperatures.' 



The present communication, v?hich is of a preliminary nature, shows that 

 a modification of this mode of examination is likely to prove a valuable 

 addition to the processes generally employed in qualitative chemical analysis. 



Apparatus and Procedure. 



As it is not generally necessary in this work to determine temperatures, 

 the following simple and cheap apparatus may be employed.' 



COVER PLATE 



"^ 



i 



m 



-5 OP 6 cms 



_ SUBLIMATION CHAMBER 



The sublimation cliamber* is a cylindrical, wooden or porcelain box 5-6 

 cms. in diameter, and 3 cms. in height, with walls about 1 cm. in tliickness. 

 The forceps FF', connected through the walls with the screws S8', are 

 hinged at about 1 cm. from the internal face, and are of sufficient length to 



1 Joly, Proc. Roy. Irish Acad., 3rd Ser., vol. ii, 1891, pp. 44-48. 



2 Fletcher, Scient. Proc. Eoy. Dub. Soc, vol. xiii. No. xxsi, February, 1913, p. 443. 



' An instrument, which it is hoped to test shortly, somewhat on the lines of the one described 

 above, has been devised for obtaining the boiling-points in vacuo of the refractory elements up to the 

 temperature of the carbon arc. 



* An annular chamber for obtaining sublimates on the meldometer ribbon in absence of free 

 oxygen was described by Joly, ibid., pp. 41 and 47. 



