Intelligence and Miscellaneous Articles. 67 



Wool, morphia, narcotine, and myrrh, yielded no carbazotic acid 

 when treated with nitric acid. — Anncles de Chimie, Fev. 1828. 



HEAT DEVELOPED DURING COMBUSTION, 



M. Despretz finds that when equal quantities of oxygen are used 

 for the combustion of the following substances, the annexed propor- 

 tions of heat are developed : 



Hydrogen 2578° 



Charcoal 2967 



Iron 5325 



Phosphorus, zinc, and tin give nearly the same quantities as iron. 

 It appears then that of all bodies, hydrogen develops the least heat 

 for the same proportion of oxygen gas absorbed ; the metals disen- 

 gage the most. It is remarkable that carbon, which does not alter 

 the volume of the gas, evolves a quantity of heat which is equal to 

 three-fifths of that given out by iron and the metals in general. — Ibid. 



ON THE SUGAR OF LIQUORICE-ROOT. 



Dobereiner and Robiquet have long since given processes for the 

 purification of this substance ; the latter precipitates it by vinegar. 

 Berzelius separates it in the following manner. The liquorice-root 

 is to be sliced and infused in boiling water ; when cold the infusion 

 is to be filtered, and' sulphuric acid added to it gradually, as long as 

 precipitation occurs. This precipitate is a compound of the acid with 

 the saccharine matter. It is first to be washed with acidulated cold 

 water, and then with pure water, till it ceases to be rendered acid : 

 the precipitate is afterwards to be digested with alcohol which sepa- 

 rates the vegetable albumen and dissolves the compound of sugar 

 and sulphuric acid j there is then to be gradually added to the solu- 

 tion carbonate of potash or soda in fine powder, and when it ceases 

 to be acid, it is to be decanted and evaporated. It is proper to leave 

 a very slight excess of acid in the solution, and for this purpose it is 

 convenient to set aside a portion to be afterwards added to the satu- 

 rated solution, until it is rendered weakly acid. The liquor is then 

 to remain in order that the sulphate of potash may separate, and af- 

 terwards it is to be evaporated. 



The saccharine matter is obtained in the form of a yellow trans- 

 parent mass, which breaks into a coarse powder resembling amber — 

 when heated in the air it swells up, inflames, and burns with a bright 

 flame, but with smoke. When in powder it burns like the lycopodium 

 or powdered resin. It suffers no change by exposure to the air. 

 The aqueous solution is precipitated by all acids, and the more per- 

 fectly as the solution is more concentrated, and especially if excess 

 of acid be used. The washed precipitates have no sour taste, but on 

 the contrary a pure saccharine flavour which is developed in a short 

 time. The precipitates are soluble in boiling water, and on cooling a 

 yellow transparent jelly is formed if the solution be concentrated. Al- 

 cohol also dissolves them, and they burn without leaving any residuum. 



The saccharine matter of liquorice combines also readily with 



K 2 bases ; 



