DECOMPOSITION OF BORACIC ACID. 15 



ti faint olive tint, and contained subborate of potash, and 

 potash. In cases when instead of water a weak solution of 

 muriatic acid was used for separating the saline matter from 

 the inflammable matter, the fluid came through the filter 

 colourless. 



In describing the properties of the new inflammable sub- Largest quan- 

 stance separated by washing, I shall speak of that collected jjf J^Xg 

 from operations conducted in tubes of brass, in thetnanner 

 that has been just mentioned; for it is in this way, that I 

 have collected the largest quantities. 



It appears as a pulverulent mass of the darkest shades Its properties. 

 of olive. It is perfectly opaque. It is very friable, and its 

 powder does not scratch glass. It is a nonconductor of elec- 

 tricity. 



When it has been dried only at 100*. or 120°, it gives off Heated in air. 

 moisture by increase of temperature ; and, if heated in the 

 atmosphere, takes fire at a temperature below the boiling 

 point of olive oil, and burns with a red light and scintilla- 

 tions like charcoal. 



If it be excluded from air and heated to whiteness in a Heated in va- 

 tube of platina, exhausted after having been filled with hi- cuo * 

 drogen, it is found very little altered after the process. Its 

 colour is a little darker, and it is rather denser ; but no in- 

 dications are given of any part of it having undergone fu- 

 sion, volatilization, or decomposition. Before the process 

 its specific gravity is such, that it does not sink in sulphuric 

 acid ; but after, it rapidly falls to the bottom in this fluid. 



The phenomena of its combustion are best witnessed in a Its combustion 

 retort filled with oxigen gas. When the bottom of the re- in oxi &- n S a3 » 

 tort is gently heated by a spirit lamp, it throws off most 

 vivid scintillations like those from the combustion of the 

 bark of charcoal, and the mass burns with a brilliant light. 

 A sublimate rises from it, which is boracic acid; and it be- 

 comes coated with a vitreous substance, which proves like- 

 wise to be boracic acid ; and after this has been washed' off, 

 the residuum appears perfectly black, and requires a higher 

 temperature for its inflammation than the olive coloured 

 substance ; and by its inflammation produces afresh portion 

 of boracic acid. 



In oximuriatic acid gas the peculiar inflammable sub- and 5n yx ; mu . 



stance "atic acid gas. 



