Improvements on Brunner^s process for Potassium. 313 



been anticipated by Dr. Gale of New York. Agreeably to my la- 

 ter experiments, I find that the receiver may be dispensed with ad- 

 vantageously on every account. I have successfully employed a 

 hollow iron cylinder of about two inches in bore, and fifteen inches 

 in length ; which is at one end fastened into the generating bottle by 

 screwing, and at the other end receives a piece of a gun barrel to 

 which a lead pipe is adapted, so as to be air tight. This pipe is re- 

 curved in such a manner, as to convey the gas and fumes into the ash 

 hole of the furnace employed. 



By means of a keg supplied with water, from which proceeds a 

 lead pipe furnished with a cock, a stream of water is directed up- 

 on the iron cylinder sufficient to keep it cool. The water as it runs 

 off from the cylinder, is caught in a flat dish, from which it is con- 

 veyed by another lead pipe. Thus refrigerated, the cylinder retains 

 nearly all the condensible potassium. The receiver should not, 

 however, be allowed at a minimum, to be below a boiling heat in 

 the coldest part, as in that case aqueous matter is detained in it, and, 

 I believe, re-oxidizes more or less of the potassium. Towards the 

 close of the process to prevent the condensible matter from obstruct- 

 ing the narrow part of the receiver next the bottle, it must be kept 

 in a state of incandescence. 



Operating with the proceeds of seven pounds of bitartrate of pot- 

 ash, properly carbonized, I have obtained of the metal in question, 

 seventeen hundred grains in pieces large enough to be conveniently 

 lifted by forceps. But as in boring the metal out of the tube in- 

 flammation is liable to ensue, unless naphtha be applied, the potassi- 

 um thus extricated is much imbued with this liquid, with which it 

 always has a reaction productive of some loss. Besides, a consid- 

 erable proportion of it, is always deposited in a state of mixture or 

 combination, with a carbonaceous matter, from which it can be com- 

 pletely separated only by intense heat. Hence I deem it prefera- 

 ble, after removing the cylinder from the bottle, to close one end by 

 screwing on an iron cap provided for that purpose, to adapt to the 

 other a piece of a gun barrel duly recurved, and proceed to distilla- 

 tion. I have tried distillation per descensum, which has the advant- 

 age of allowing a portion of the metal to be extricated by simple fu- 

 sion. The last portions however can only be obtained at a white 

 heat. I must confess that I have not as yet been enabled to make 

 up my mind as to the method, which may be upon the whole prefer- 

 able in this part of the process. From actual trials it appears that 

 it is possible to receive the potassium, as it comes over by distillation, 



