236 ANNUAL OF SCIENTIFIC DISCOVERY. 



warmed and held in a current of hydrogen gas. Ann. der Cliemie 

 und Pharmacie, Ixxxi. 



ON THE DECOLORIZING POWER OF CHARCOAL AND OTHER BODIES. 



IT is generally said that charcoal is the only simple body which 

 possesses the property of absorbing coloring matters dissolved in a 

 liquid ; it results, moreover, from the labors of Bussy and Payen, that 

 decoloration by charcoal is a purely physical phenomena, a phenomena 

 of dyeing. Several compound bodies, (alumina, sulphuret of lead 

 prepared by the humid way, and hydrate of lead) also possess the 

 property of decoloring liquids ; but chemists for the most part, regard 

 the action which the oxides exert on coloring matters in the prepar- 

 ation of lakes as a chemical action, different from that of charcoal. 

 However, Berzelius thought he might compare the decoloration by 

 the oxides and the metallic salts with that produced by charcoal. In 

 a communication submitted to the French Academy by M. Filhol, the 

 author proves that charcoal is not the only simple body which possesses 

 the property of decoloring liquids ; sulphur, arsenic, and iron, resulting 

 from the reduction of hydrogen, have appreciable decoloring power. 

 The number of compound bodies endowed with an appreciable decol- 

 oring power is much greater than has been supposed, as this property 

 seems to depend much more on the state of division of these bodies 

 than on their chemical qualities. It was also shown that a certain body 

 which easily appropriates one coloring matter, may have very little 

 tendency to remove another ; thus bone phosphate of lime (artifically 

 obtained) with difficulty decolors a solution of sulphindigotate of soda, 

 whilst it acts on tincture 'of litmus more energetically than animal 

 black. The decoloration is in the great majority of cases, a purely 

 physical phenomena ; thus, the same coloring matter is absorbed by 

 metalloids, metals, acids, bases, salts, and organic substances, besides it 

 is easy, by employing suitable solvents, to procure the color unaltered 

 from the body by which it had been absorbed. Comptes Rendus, 1852. 



DEODORIZING PROPERTIES OF COFFEE. 



THE London Medical Gazette gives the result of numerous experi- 

 ments with roasted coffee, proving that it is the most powerful means, 

 not only of rendering animal and vegetable effluvia innocuous, but of 

 actually destroying them. A room in which meat in an advanced 

 degree of decomposition had been kept for some time, was instantly 

 deprived of all smell, on an open coffee roaster, being carried through 

 it, containing a pound of coffee newly roasted. In another room 

 exposed to the effluvium occasioned by the clearing out of a cess pit, 

 so that sulphuretted hydrogen and ammonia in great quantities could 

 be chemically detected, the stench was completely removed within half 

 a minute, on the employment of three ounces of fresh roasted coffee, 

 whilst the other parts of the house were permanently cleared of the 



