Zeise on the Hydroxanthic Acid. 301' 



addition of a greater quantity of water. Xanthic oil does not 

 affect the colour of litmus or turmene ; it acts in no manner on 

 nitrate of lead ; it does not cause a precipitate with muriate of 

 copper. At the approach of a flaming body, it readily takes fire, 

 burns with a bluish flame, and gives rise to much sulphureous 

 acid, mingled undoubtedly with carbonic acid. Water is con- 

 densed on the sides of a bell-glass suspended over the flame. 



The red matter is deliquescent; dissolves completely in water; 

 the solution is at first reddish, but soon becomes yellowish- 

 brown. It strongly reddens turmeric. Alcohol acts but slowly 

 on this substance. 



The watery solution of the red matter, recently made, preci- 

 pitates the salts of lead red ; but commonly the precipitate 

 becomes soon black ; the cupreous salts are precipitated of a 

 black-brown*. It does not occasion a precipitate with the 

 salts of barytes ; but a solution of the nitrate of barytes is 

 coloured yellow. It makes a lively effervescence with acids, 

 giving rise to an odour of sulphuretted hydrogen mingled with 

 that of carburet of sulphur, — and there are, at the same time, 

 separated globules of an oleaginous liquid ; but no precipitate 

 of sulphur takes place. A slip of paper imbued with nitrate of 

 lead, and then exposed to the gas disengaged by muriatic acid, 

 is coloured partly black and partly red. When exposed to the 

 air, the red matter passes a little towards yellow. 



The crystalline matter speedily deliquesces, and it dissolves 

 in water without leaving any residuum. The solution is of a 

 very intense brown-black, so that, before diluting it to a certain 

 degree, the liquid appears nearly opaque ; it becomes turbid on 

 contact of air; and sulphuretted hydrogen, as well as a little 

 sulphur are disengaged from it by acids. The matter treated 

 with a red heat, seems analogous to a mixture of sulphuret of 

 potassium with charcoal. 



Hydroxanthate of potash, thrown on a glass-plate, red hot, rea- 

 dily takes fire, and burns quietly with a bluish flame ; but if we set 

 fire to it at the point of the flame of a candle, it burns with much 

 energy, emitting sparks extremely brilliant. This somewhat 

 singular phenomenon is, probably, due to flocks of charcoal, 

 formed and projected by a partial decomposition of the salt, 

 when it is exposed to a very strong heat which penetrates 

 into the interior of the mass. 



M. Zeise has prepared hydroxanthates of soda and ammonia, 

 with alcoholic solutions of these alkalis and carburet of sul- 

 phur; hydroxanthates of barytes and lime, with the carbonates of 

 these bases and hydroxanthic acid. The hydroxanthate of 

 lime may also be obtained, but with difficulty, in a state of 



* The solution is ia this respect very similar to that obtained, according 

 to M. Berzelius. by disjesling for a long time in the cold an aqui^ous solu- 

 tion of potash with carburet of sulphur ; or by adding carburet of sulphur 

 to a watery solution of hepar. — Ann. de Ch. el de fhijs. xx. 243. 



