Intelligence and Miscellaneous Articles. 371 



and far more rational than the methods usually eniploj'ed. It may 

 be objected to it, that it takes more time ; but not only are far more 

 correct results obtained by it, but it is also capable of answering 

 several questions as to how or in what combinations the constituents 

 found in the ash were contained in the organic substance. According 

 to the method which I propose, the organic substance is charred at 

 a very faint red heat, so that the water with which it is extracted is 

 not coloured yellowish or brownish. At this temperatui'e, which, 

 owing to the volatilization of so many substances, is much lower thau 

 would appear, no alkaline chlorides are volatilized, nor can clilorine 

 be expelled from them in the form of hydrochloric acid by acid 

 phosphates. The alkaline and earthy phosphates are not able to 

 expel the carbonic acid from the alkaline carbonates, either contained 

 in the organic substance or formed by the charring ; nor can phos- 

 phoric acid be eliminated from its combinations by silica, reduced 

 by carbon, and volatilized in the form of phosphorus. The charring 

 is effected either in a spacious covered platinum crucible over a 

 spirit-lamp, or, with larger quantities of the organic substances, in a 

 spacious covered Hessian crucible, especially if they do not fuse. 

 When there is jio longer much empyreumatic odour perceptible, the 

 heating is discontinued, the cold mass left for some time in contact 

 with water, and the solution of the soluble salts furthered by heating; 

 the edulcoration requires considerable time and nmch hot water ; but 

 if the highest degree of accuracy is not desired, the edulcoration 

 may be discontinued when several drops of the wash-water leave a 

 scarcely perceptible residue on evaporation upon a slip of platinum ; 

 this point is very soon attained. 



The aqueous extract contains the alkaline salts. The alkaline 

 chlorides were contained as such in the organic substance previous 

 to the charring, as well as at least a part of the alkaline sulphates and 

 phosphates. If, as in most cases, carbonated alkali is found in the 

 aqueous extract of the charred mass, it either pre-existed in the 

 organic substance, or the alkali in it was combined with an organic • 

 acid or some other organic body, which acted the part of an acid 

 towards the alkali. If the organic substance contain sulphate of 

 lime, this, when carbonated alkalies are present in sufficient quantity 

 in the charred mass, is converted, on treating the latter with water, 

 into carbonate of lime and alkaline sulphate. In the same way, 

 when phosphate of lime is present, a cei'tain quantity of alkaline 

 phosphates is formed from it in the aqueous extract by the alka- 

 line carbonates. Carbonated alkali and phosphate of lime are not 

 perfectly decomposed even by fusion at very high temperatures. 

 The decomposition in presence of much water is likewise imperfect, 

 and the more alkaline phosphate is obtained in the aqueous extract, 

 the more concentrated the solution, the more carbonated alkali 

 it contains, and the longer the charred mass has been digested at 

 an elevated t(!mporature. Alkaline sulphates and phosphates will 

 however be found in far smaller quantities in the aqueous extract of 

 the charred mass than was to be exijccted from the ash analyses that 

 have been hitherto published. Frequentlv the two, and especially 

 2 C 2 ' 



