406 Progress of Foreign Science. 



The extractive matter was now subjected to the action of alcohol 

 at 40° (8.817,) in order to separate the portion of sugar which it 

 contained. The quantity of sugar furnished by each was nearly 

 the same ; but that of the Odessa specimen was coloured and 

 faintly bitter. 



The residuum insoluble in alcohol, was digested with water, 

 and concentrated. It became viscid, was somewhat whitish, 

 without any marked taste, and a little coloured. Silicated pot- 

 ash yielded a precipitate, indicating the presence of gum. To 

 determine what salts are contained in these flours, they took 

 100 parts of each, and calcined them slightly in a platinum 

 crucible. The carbonaceous residuum was pulverized, and 

 treated with boiling water ; this filtered and evaporated to dry- 

 ness, gave for each flour about 0.15 of saline matter, and a 

 minute portion of silica. 



On examining the bread manufactured with these two kinds 

 of flour, the French was found to be the sweetest, but the other 

 kept longer fresh. — Jour, de Pkarm. Feb. 1822. 



On Carbon considered as a discolourmg substance, by M. A. 

 Bussy. — This memoir, to which the Pharmaceutical Society of 

 Paris has very properly adjudged the first prize, is preceded by 

 general considerations on colouring matters, which the limits of 

 our Journal do not permit us to detail. M. Bussy, in order to 

 shew that the action of a chemical body varies much according 

 to the physical state in which it occurs, quotes the fact that 

 gelatinous alumina deprives of colour decoctions of almost all 

 ■dyewoods, whilst it has no action on them, when it has acquired 

 cohesion by desiccation. On adding likewise to a liquor, a so- 

 'lution of acetate of lead, we destroy the colour by occasioning 

 a precipitate, which carries with it a portion of the colouring 

 matter, whilst the same precipitate in the dry state would ex- 

 ercise no action on it. 



M. Bussy's first chapter treats of the manner of comparing 

 together the discolouring or blanching powers of different char- 

 coals. The solution of indigo in sulphuric acid appears to him 

 the best means to be employed for establishing in an exact and 

 comparative manner, the discolouring power of different charcoals. 

 1st, Because we can always know the exact quantity of colour- 

 ing matter on which we act, from the weights of indigo dis- 

 solved, and water of dilution. 2d, Because the marked hue of 

 indigo does not suffer us to hesitate concerning the blanching 

 of the liquor, when it occurs. 3d, Because indigo is less sus- 

 ceptible than any other matter of being altered by light, heat, 

 tVc, which might exercise some influence on the results. 



It might, indeed, be properly objected, that the acid of tha 

 solution may act upon the substances foreign to the charcoal. 

 To avoid this inconvenience, M. Bussv look a solution made 



