POTASIUM. 



conductor in a high degree : a most in- 

 tense light was exhibited at the negative 

 wire, and a column of flame, which seem- 

 ed to be owing to the developement of 

 combustible matter, arose from the point 

 of contact. Mr. Davy next tried several 

 experiments on the electrization of pot- 

 ash rendered fluid by heat, with the hope 

 of being able to collect the combustible 

 matter, but he was still unsuccessful, 

 " and I only," says he, " attained my ob- 

 ject by employing electricity as the com- 

 mon agent for fusion and decomposition." 

 Potash perfectly dried by ignition is a 

 non-conductor; by a very slight addition 

 of moisture, which does not perceptibly 

 destroy it aggregation, it is rendered a 

 conductor, and in this state it readily fus- 

 es and decomposes by strong electrical 

 powers. A small piece of pure potash 

 was placed upon an insulated disc of pla- 

 tina, connected with the negative side of 

 the battery, in a state of intense activity ; 

 and a platina wire, communicating with 

 the positive side, was brought in contact 

 with the upper surface of the alkali, a vi- 

 vid action took place, and the potash be- 

 gan to fuse at both points of electrization. 

 There was a violent effervescence at the 

 upper surface ; at the lower, or negative 

 surface, there was no liberation of elastic 

 fluid; but small globules, having a high 

 metallic lustre, appeared ; these were si- 

 milar in visible character to quicksilver : 

 some of them burnt with explosion and 

 bright flame as soon as they were formed, 

 and others remained, and were merely 

 tarnished, and finely covered with a white 

 film, which formed on them. "These 

 globules," said the professor, " numerous 

 experiments soon shewed to be the sub- 

 stance I was in search of, and a peculiar 

 inflammable principle the basis of potash. 

 I found that the platina was in no way 

 connected with the result, except as the 

 medium for exhibiting the electrical pow- 

 ers of decomposition ; and a substance of 

 the same kind was produced when pieces 

 of copper, silver, gold, plumbago, or even 

 charcoal, were employed for completing 

 the circuit." 



Soda, when acted upon ia the same 

 manner, exhibited an analogous result, 

 and these effects equally took place in 

 ihe atmosphere, and when the alkali was 

 acted upon in the vacuum of an exhausted 

 receiver; but these globules could not 

 in either case be produced from crystal- 

 lized alkalies. When a globule of the 

 base of potash was exposed to the atmo- 

 sphere, it immediately attracted oxygen, 

 and a white crust formed upon it, which 



proved to be pure potash. When the 

 globules were strongly heated, and then 

 suspended in oxygen gus, a rapid com- 

 bustion with a brilliant white flame was 

 produced, and these metallic globules 

 were converted to an alkali, whose weight 

 greatly exceeded that of the combusti- 

 ble matter consumed. When Mr. Davy 

 had thus detected the basis of the fixed 

 alkalies, he had considerable difficulty to 

 preserve and confine them, so as to ex- 

 amine their properties and submit them 

 to experiments. He found, however, 

 at length, that in recently distilled naph- 

 tha they may be preserved many days, 

 and that their physical properties may 

 be easily examined in the atmosphere, 

 when they are covered by a thin film 

 of it. The basis of potash, at 60 Fah- 

 renheit, is only imperfectly fluid ; at 

 70 it becomes more fluid ; and at 100 

 its fluidity is perfect, so that different 

 globules may be easily made to run in- 

 to one. At 50 it becomes a soft and 

 malleable solid, which has the lustre of 

 polished silver ; and at about the freez- 

 ing point of water it becomes harder 

 and brittle, and when broken in frag- 

 ments exhibits a crystallized texture, of 

 perfect whiteness and high metallic 

 splendour. To be converted into vapour, 

 it requires a temperature approaching 

 that of the red heat. It is an excellent 

 conductor of heat, and a perfect con- 

 ductor of electricity. 



Resembling the metals in all these 

 properties, it is, however, remarkably 

 different from any of them in specific 

 gravity ; for it will not sink in double 

 distilled naphtha, whose specific gravi- 

 ty is only .770, that of water being con- 

 sidered a 1.000. Mr. Davy has deter- 

 mined by experiment, that its specific 

 gravity is to that of mercury as 10 to 

 223, which gives a proportion to that 

 of water nearly as 6 to 10 ; so that it 

 is the lightest fluid body known. When 

 this substance is introduced into oxy- 

 muriatic acid gas, it burns spontaneous- 

 ly with a bright red light, and muriate 

 of potash is formed. When thrown up- 

 on water, it decomposes it with great vio- 

 lence, and an instantaneous explosion is 

 produced with brilliant flame, and a so- 

 lution of pure potash is the result. 



When a globule is placed upon ice, 

 not even the solid form of the two sub- 

 stances can prevent their union ; for it in- 

 stantly burns with a bright flame, and a 

 deep hole is made in the ice, which is 

 found to contain a solution of potash. 

 When a globule is dropped upon moist- 



