S70 Intelligence ajid Miscellaneous Articles. 



mass, extracted with water, was now treated with hydrochloric acid ; 

 the filtered solution did not yield with ammonia a very considerable 

 precipitate, which, although it looked almost like pure hydrated 

 oxide of iron, contained some phosphoric acid as well as lime and 

 magnesia. In the filtered solution, I obtained with oxalate of am- 

 monia a pretty considerable precipitate of oxalate of lime, proving 

 the presence of carbonate of lime in the charred blood ; and in the 

 liquid separated there was also a small quantity of magnesia. The 

 cinder, after treatment witii Mater and hydrochloric acid, yielded a 

 very considerable quantity of a red-coloured ash on being burnt in 

 an atmosphere of oxygen. It was in a semifused state, and contained 

 peroxide of iron (which formed the chief part), earthy and alkaline 

 phosphates*. 



If the fixed constituents in plants are examined according to the 

 above process, totally different results are frequently obtained to those 

 yielded by the ash analyses which have been published up to this time. 

 The ashes of peas have been examined by Fresenius and Will, Bichon, 

 Thon and Boussingault ; none of them enumerate carbonic acid 

 afnong the constituents. From the investigations which have been 

 made by Drs. Gibbs and Bromeis in my laboratory, the amount of 

 carbonic acid in the salts which are extracted froni the charred peas 

 by water amounts to somewhat more than 27 per cent. Evidently, 

 in the former method of reducing to ash, the carbonic acid has been 

 entirely expelled. Phosphoric acid is only present in small quantity 

 in the aqueous extract of charred ]3eas. When the charred peas are 

 subsequently treated with hydrochloric acid, a solution is obtained 

 which contains a moderate quantity of earthy phosphates. If tlie 

 charred peas are now perfectly reduced to ash in an atmosphere of 

 oxygen, a very considerable quantity of ash is obtained, which con- 

 sists principally of earthy and alkaline phosphates. 



That the n.elhod of preparing the ash of organic substances has con- 

 siderable influence upon the composition of the ash has already been 

 noticed by several chemists, especially by Erdmannf , who showed 

 that acid phosphates, which yielded wliitc precipitates with nitrate 

 of silver by ignition with carbon, lost a considerable portion of the 

 phosphoric acid, and then produced a yellow j^recipitate in the solu- 

 tion of silver; he observed further, that chlorine and sulphuric acid 

 might be contained in very different quantities in the ashes, according 

 to the mode of preparing them ; and that in the ashes of many seeds 

 not a trace of chlorine had been found, while the aqueous extract of 

 the seed contains very perceptible quantities of chloride of sodium. 

 Mitscherlich J has likewise drawn attention to several circumstances, 

 by which, in incinerating organic substances, the ashes are frequently 

 decomposed and vendered impure. 



The mode of determining the fixed constituents of an organic 

 substance, as above described, appears to me more advantageous 



* After these obsei-vations had been penned, I observed that Lehmann had 

 proved the presence of alkaline carbonate in the blood by a different method. — 

 See Chem. Caz., vol. v. p. 133. 



t Chem. Gaz., vol. iv. p. 230. % Ibid, vol. iv. p. 69. 



