Journal . l quantities ofammonia or ammonium salts ; the cause ot this is thatthese acids are not aide to decompose the ammoniumsalt of congo red. The action of inorganic acids isalso interfered with by ammonium salts. Several dropsof hydrochloric and dilute sulphuric acid can be addedto a solution of Congo red in glacial acetic acid beforeany change in colour takes place, and then this onlvhikes place gradually : a considerable quantity of theacid must be added before the blue coloration forms. —C. A. K. Separating and Extracting Apparatus. K. Zeit. H, 1159. The aim of the appa
Journal . l quantities ofammonia or ammonium salts ; the cause ot this is thatthese acids are not aide to decompose the ammoniumsalt of congo red. The action of inorganic acids isalso interfered with by ammonium salts. Several dropsof hydrochloric and dilute sulphuric acid can be addedto a solution of Congo red in glacial acetic acid beforeany change in colour takes place, and then this onlvhikes place gradually : a considerable quantity of theacid must be added before the blue coloration forms. —C. A. K. Separating and Extracting Apparatus. K. Zeit. H, 1159. The aim of the apparatus is to prevent the loss ofsolution which occurs during extracticn and and a> are two glass vessels, either of the same sizeor of different sizes, connected by a three-way cock (asshown in figure). Tubulures e and e fitted withstoppers, are fixed in the side of the vessels a and a;the edges of the tubulures are in part bent back, andthe stoppers are provided with a hole, or are ground. unevenly, so as to admit of the vessels « andn1 beingconnected with the air by placing the stoppers in acertain position. The solution to be extracted, togetherwitli the extracting medium, is placed in either of thetwo vessels, the stop-cock between the two being extraction, e and f1 are opened and the extractrun from the one vessel to the other. The process can,of course, be repeated as required : the liquids can bepoured off through e, c1 or the three-way cock. —C. A. K. XXII—ANALYTICAL CHEMISTRY. Conqo Bed as a Reagent for Free Acid. C. Wurster. f. Phys. H, BKlCKE (Chem. Zeit. 11. 315] concludes that sincehuman urine does not affect Congo red solution, it doesnot contain anv free acid or carbon dioxide. The Lavrents New Polarimeter. Kauders. Oesterr. Ztschr. f. Zuckerind. 16, « is a half-shadow instrument; it has a scale ofsaccharimeter degrees from-200 to + 4C0, and a dividedarc from - 45* to + 90*. The verniers are so arrang
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectchemist, bookyear1882
