Chemical Scierice, 475 



yolatilized, and a metallic button is left, having the colour and 

 splendour of tin. A fuller account of the researches of M. Oersted 

 on tliis subject is expected. — Ilensmann's Repertoire — Phil. Mag, 

 N. S, ii. 



18. Mutual Action of Lime and Litharge. — M. Fournet heated 

 a mixture consisting of 7.12 parts of calcined lime, and 27.89 parts 

 of litharge, very strongly; a coherent mass was obtained, which, 

 pulverized and digested in water, gave, when filtered, a perfectly 

 clear and colourless liquor, which, when treated with sulphuretted 

 hydrogen, threw down an abundant black precipitate ; hence oxide 

 of lead is rendered soluble in water by means of lime. — fAnn. det 

 Mines, i. 538. 



19. New Chloride of Manganese discovered by M. J. Dumas.-— 

 This chloride corresponds in proportions to the manganesic acid, 

 and in contact with water, produces muriatic and manganesic acids^ 

 It is easily obtained by putting a solution of manganesic acid into 

 contact with concentrated sulphuric acid, and fused common salt. 

 Water and the new chloride are formed ; the former is retained by 

 the acid, the latter volatilizes in a gaseous form. The body does not^ 

 however, appear to constitute a permanent gas *, for though, when 

 produced, it appears as an elastic fluid having a cupreous or green- 

 ish tint, yet when passed into a tube, cooled to 5° or 4° Fahrenheit, 

 it condenses into a liquid of a brownish green colour. 



When the perchloride is produced in a large tube, its vapour 

 gradually displaces the air present, and the tube becomes filled 

 with it; if it then be poured into ajar with moistened sides, the 

 colour of the gas changes as it comes into contact with the moist 

 air ; a thick smoke of a fine rose colour appears ; and the sides of 

 the vessel acquire a deep purple colour due to the manganesic acid 

 formed. The water thus coloured is abundantly precipitated by 

 nitrate of silver, and, acted upon by a solution of potash, produces 

 all the changes of the mineral chamelion. 



The most simple process for the preparation of this body appears 

 to be to form a common green chamelion, to convert it into red 

 chamelion by sulphuric acid, and to evaporate the solution, which 

 will give a residue consisting of sulphate and manganesate of 

 potash. This mixture, acted upon by concentrated sulphuric acid, 

 produces the solution of manganesic acid, into which the commcm 

 salt is to be thrown in small pieces, until the vapours which rise are 

 colourless ; the latter effect is a sign that all the manganesic acid is 

 decomposed, and that muriatic acid only is produced. 



An analogous compound is formed when a fluoride is used in. 

 place of the common salt. But all attempts as yet made to collect 

 a sufficient quantity for examination have failed; the chloride, on 

 the contrary, is easily formed and examined, although it is not so 

 easy to preserve it. — Annates de Chimie, xxxvi. 81. 

 * Query, what is a permanent gas P-*'Ei>. 



