071 the Sails usually called Hyperoxymuriates, &c. 427 



1 endeavoured to procure the substance which coloured the 

 sulphuric acid during its action upon hyperoxymuriate of potassa, 

 and after several failures, in which explosions took place, I at 

 length succeeded in the following manner. Dry oxymuriate of 

 potassa in powder was mixed with a small quantity of sulpliuric 

 acid, and thev were rubbed together with a spatula of platinum 

 till they had incorporated, and formed a solid mass of a bright 

 orange colour. This mass was introduced into a small retort 

 of glass, and exposed to the heat of water which was gradually 

 warmed; a bright yellowish green, elastic fluid arose from the 

 mixture, which was rapidly absori)ed by water, giving to it its 

 own tint, but which had no sensible action on mercury. 



To make this experiment without danger, not more than 50 

 or 60 grains of the hyperoxymuriate should be employed, great 

 care should be taken to prevent any combustible matter from 

 being present, and the water should not be permitted to attain 

 a temperature equal to 212*^, which may be easily managed by 

 mixing it with alcohol. There are dense white fumes when the 

 mixture is first made, but there seems to be no heat produced ; 

 a small quantity of the orange gas is disengaged at this time; 

 but the greater part of it remains attached to the sulphuric acid 

 in the solid mass, and is expelled from it by the heat. 



The gas procured by this process over mercury, when com- 

 pared with the gas procured from the ayperoxymuriate, by liquid 

 muriatic acid, is found to have a much more brilliant coIotu', is 

 much more rapidly absorbed by water, has a peculiar and much 

 more aromatic smell, unmixed with any smell of chlorine. It 

 destroys moist vegetable blues without previously reddening 

 them. When it is heated to a temperature about that of boiling 

 water, it explodes with more violence than euchlorine, and greater 

 expansion of volume, producing much light. After the explo- 

 sion over mercury, rather less than three (from 2-7 to 2-9) vo- 

 lumes appear for two of the gas decomposed, and of these, two 

 are oxvgen, and the remainder chlorine. 



A little chlorine is always absorbed by the mercury during the 

 explosion of the gas ; and it appears reasonable to conclude, that 

 the deep yellow gas is in reality composed of two in volume of 

 oxygen, and one of chlorine, condensed into the space of two 

 volumes, and that it consists in weight, of one proportion of 

 chlorine G7, and four of oxygen 60. 



None of the combustible bodies which I have tried, decom- 

 pose this gas at common temperatures, except phosphorus ; this 

 when introduced into it occasions an explosion, and burns in 

 the liberated gases with great brilliancy. 



Its saturated solution in water is of a deep yellow colour, it 

 does not taste sour, but is extremely astringent and corroding ; 



when 



