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CARAMELS & COLORINGS for all purposes. 7-8, Idol Lane, Great Tower St., London, E.C., A. BOAKE, ROBERTS & CO. (LIMITED) Licensed Trader in Alcohol and Spirits of Wine. Stock kept in suitable packages ready for immediate use. Stratford, London, E. The reagents employed are NOBr, NOCI, NH3, PC15, SOCl2, Ag2O, KOH, HNO2, KNO2 and HCl, MeOH, and H2O. In only one case does the reagent exhibit a constant behaviour, that is in the case of PCl5. In all other cases the sign of the active product is sometimes the same as and sometimes the opposite to that of the parent body. There seems to be no experimental evidence as to whether thionyl chloride is constant in its behaviour or whether it resembles the other reagents. Disregarding the exception named above, it would seem that the direction of the reaction is dependent on the Reagent. SOCI2 Ag2O KOH NaOH NaOCH3 NOBr NOCI H2O NH3 HNO2 Direction of reaction. d -d d. d d d Thus NOBr on d-alanine ester (no free carboxyl) gives rise to d-a-bromopropionic ester. On the other hand, the same reagent on d-alanine itself (one free carboxyl) gives rise to l-a-bromopropionic acid. From the twenty-six examples given above there seems to be only one exception, that of d-a-bromoisovaleric acid, which under the influence of ammonia gives rise to l-valine It is thus possible when the d-isomer would be expected. to predict the sign of any product under the influence of any definite reagent by studying the number of free carboxyl groups present. The behaviour of the dialkyl esters of dibasic acids and of the mono- di-, and tri-alkyl esters of the tri-basic acids, &c., would be of interest. THE ABSORPTION OF LIGHT BY WATER CHANGED BY THE PRESENCE OF STRONGLY HYDRATED SALTS, AS SHOWN BY THE RADIOMICROMETER.* NEW EVIDEnce for the SOLVATE THEORY OF SOLUTION. By J. SAM GUY, E. J. SHAEFFER, and HARRY C. JONES. (Concluded from p. 30). WHEN salts which are strongly hydrated in aqueous solutions are not very concentrated, the difference between the transparency of the salt solution and that of water of the same depth of layer as the water in the solution is not so pronounced. This is what would be expected, since the total amount of water combined with the dissolved salt increases with the concentration of the solution. The data given in Table V. bring out this fact. The depth of layer of the different solutions for which the results are recorded in Table V. was the difference between 21 and 1 mm., i.e., 20 mm. The results are, therefore, comparable with those recorded in Table III., the difference being a difference in the concentrations of the solutions used. It will be seen from a glance at the table that the difference between the transmission of the solution and that of water at the same depth as the water in the solution is very much less for the more dilute than for the more concentrated solutions. As has already been pointed out, this is exactly what would be expected in terms of the solvate theory applied to the phenomenon in in question. Considerable work was done in comparing directly the transmission of a solution and that of water having the same depth as the water in the solution in question. The deflection of the radiomicrometer as given by the solution is in the column marked "I sol." and the deflection as given by water having the same depth as water in the solution is given in the column marked "I。 H2O." * From the American Chemical Journal, xlix., No. 4. |