60 Processes for Potassium. 



Art. V .—Description of a newly modified Apparatus for obtaining 

 Potassium, accompanied by remarks on the Redistillation and 

 Preservation of this metal; by L. D. Gale, M. D. Assistant to 

 the Professor of Chemistry in the College of Physicians and 

 Surgeons in the city of New lork. 



TO PROrESSOR SIIiLIMAN. 



Dear Sir. — Since you did me the honor to publish in this Journal 

 an account of some experiments performed in the laboratory of the 

 College of Physicians,* he, I have repeated those experiments with 

 the view of improving some part of the apparatus, and particularly 

 the receiver. It will be recollected that the receiver of the appara- 

 tus above alluded to, consists of an inch and a half tube of wrought 

 iron screwed into the retort. 



A serious objection to this receiver is, that it becomes clogged, long 

 before the operation is finished ; and notwithstanding we can clear it 

 once or twice, by means of an iron rod, adapted to the purpose, yet 

 it soon becomes completely filled, and impermeable to the rod, thus 

 obliging us oftentimes to stop the process before it is half completed. 

 The first substitute for the tube receiver consisted of a common 

 quicksilver bottle connected with the retort, (also a quicksilver bottle,) 

 by a straight piece of wrought iron, screwed into the mouth of each 

 bottle. A small hole was bored in the opposite end of the receiver, 

 for inserting a smaller iron tube, termed the safety tube, for dis- 

 charging the uncondensed gases. 



The advantages proposed in this kind of receiver over that form- 

 erly used were, 1st. To avoid any interruption of the process, until 

 all the metal contained in the retort had disdlled over. 2nd. To 

 . make use of the receiver for redistilling the potassium. This is done 

 by unscrewing the end of the tube next to the retort, stopping 

 the hole for tlie safety tube by an iron plug, and lastly inverting 

 the receiver into the furnace to redistil its contents, without the 

 trouble and expense of using naphtha, transferring the materials to 

 another vessel for redistillation, and heating the furnace a second time. 

 My first object was completely achieved by this apparatus. The 

 second, was not so happily accomplished. The receiver was too 

 large, aflxDrding so much surface of iron (which in these bottles is 

 always more or less oxidated) that the potassium acquires oxygen from 



* See Vol. XIX, p. 205, 



