218 Intelligence and Miscellaneous Articles, 



and therefore without the decomposition of the acids, because the 

 silver is oxidated by the oxygen of the peroxide of manganese. — 

 Poygendorff's Annals, v. 41, p. 344. 



A NEW METHOD OF OBTAINING CHROME ALUM, BY 

 R. F. MARCHAND. 



When bichromate of potash is dissolved in hot hydrochloric acid, 

 upon cooling, the crystallized compound, discovered by Peligot, of 

 chromic acid with chloride of potassium is formed, and there remains 

 in the mother liquor chloride of potassium and chloride of chrome. 

 If, instead of the bichromate, the chromate of potash is substituted, 

 no compound of chromic acid with chloride of potassium is formed, 

 but a mixture of chloride of chrome and chloride of potassium is ob- 

 tained ; the latter salt may be completely separated by crystallization. 



If to the hydrochloric acid about one-eighth of its weight of sul- 

 phuric acid is added, one half of the chromic acid is converted into 

 oxide of chrome, which combines with the sulphuric acid and the 

 sulphate of potash, and the double salt of chrome alum is obtained ; 

 at the same time there is formed chloride of potassium, which, if 

 sulphuric acid is added in excess, is converted into sulphate of pot- 

 ash, and bichloride of chrome is formed, which, upon evaporation, 

 disengages chlorine with the production of chloride of chrome. 



Fischer's method of preparing chrome alum by means of bichro- 

 mate of potash, alcohol, and sulphuric acid, is so simple and advan- 

 tageous, that any other method of procuring it is rendered unneces- 

 sary ; but still the formation of oxide of chrome from chromic acid, 

 by this method, is not altogether without theoretical interest, even 

 if, in practice, it cannot be turned to account. — Poggendorff's An^ 

 nals, p. 594. 



EXAMINATION OF MALT LIQUORS. 



Professor J.N. Fiichs of Munich has devised the following method 

 of examining malt liquor with regard to the ingredients contained 

 in it, which he calls a " Hallymetrische Bierprobe." It is founded 

 on the solubility of common salt in water; 36 parts of salt che- 

 mically pure being dissolved by exactly 100 parts of water. 



A graduated tube is previously prepared, called a ** Hallymeter." 

 It consists of two glass tubes, one narrow, the other wide, joined to- 

 gether, somewhat funnel-shaped, of a capacity rather more than suf- 

 ficient to hold the required fluid and the undissolved salt. The 

 smaller and lower part of the tube is so graduated as for the larger 

 divisions to contain 5 grains of prepared salt with space between 

 each division, so that it may be divided into tenths : it is graduated 

 with powdered salt in a saturated solution of salt, the salt being pre- 

 viously sifted through a fine sieve. 



First process. — 330 grains of common salt are added to 1000 grains 

 of the beer under examination in a covered glass vessel. It is heated 

 in warm water to the temperature of 100° Fahrenheit ; the salt is 

 thereby dissolved in about five minutes. It is cooled, and by care- 

 fully blowing through it, all the carbonic acid is expelled. The so- 



