Intelligence and Miscellaneous Articles. 153 



the compound of chromium by treating mixtures of the seleniates 

 and chloride of sodium with sulphuric acid, chlorine and chloride 

 of selenium analogous to selenious acid were obtained; and towards 

 the end of the experiment green vapours rose, which condensed 

 into an oily liquid composed of the selenious and sulphuric acids. 



Bromide and iodide of potassium mixed with bichromate of pot- 

 ash, and acted on by sulphuric acid, liberate respectively bromine 

 and iodine in a state of purity without the slightest admixture of 

 chromium. — Ann. de Chimie, January, 1836. 



ON THE ACTION OF SULPHURIC ACID ON OILS. 



M. Fremy in examining the kind of saponification which sulphu- 

 ric acid exerts upon oil, has arrived at several facts in addition to 

 those already ascertained by MM. Chevreul, Braconnot, and Ca- 

 ventou. The oils employed were olive and almond, and the results 

 from both were perfectly similar. When olive oil is treated with 

 half its weight of concentrated sulphuric acid, surrounding the 

 vessel \vith a freezing mixture to prevent any elevation of tem- 

 perature and consequent evolution cf sulphurous acid, the acid 

 being added very cautiously, after a few minutes the mixture be- 

 comes viscid, when the action is finished. Then the mass being 

 treated with water, rather less than six times the bulk of the oil 

 employed, the mixture separates into two strata; the superior is of 

 syrupy consistence, whilst the lower is chiefly composed of water 

 and sulphuric acid; this latter is a sulphoglycerate of lime(?), 

 whilst the superior layer is a mixture of three acids, which he calls 

 sulphostearic, sulphomargaric, and sulpholeic acids. 



Tlie aqueous solution of these acids decomposes in a few days, 

 sulphuric acid being formed, and the three fatty acids precipitated. 



The sulphostearic and sulphomargaric acids possess little sta- 

 bility, as they always decompose in from 24' to 48 hours at most, 

 which property M. Fremy has availed himself of to separate these 

 two solid acids from the third, which is liquid, and is derived from 

 the decomposition of sulpholeic acid. The two solid acids can be 

 separated by means of alcohol ; these he has named hydrostearic 

 and metamargaric acids. 



Hydrostearic acid is solid, white, insoluble in water, soluble in 

 both alcohol and aether, from which it crystallizes in maramillated 

 groups; it fuses at about 129° Fahr. Its composition is C'' H'- O*: 

 it loses i an equivalent of water when in combination with bases. 

 It may be volatilized without alteration. All its salts are insoluble 

 in water, except the hydrostearates of soda and ammonia. 



Metamargaric acid is white like the preceding; soluble in alcohol; 

 fuses at 120' Fahr. Its composition is given in the formula C* 

 H"" O'J- Jt loses i an equivalent (1|?) of water in combining 

 with bases, and becomes C*' H'' O', that is, exactly the same com- 

 position as common margaric acid. 



Ilydroleic acid is a slightly coloured liquid at 32° Fahr.; is com- 

 posed ofC'' II'''' O'^; loses 5 an equivalent of water by combination, 

 and becomes C'' II''' O', When distilled it is almost totally de- 

 composed into carbonic acid, water, and an oil composed almost 



