248 THE ANALYST. ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. FOODS AND DRUGS ANALYSIS. The Analysis of Dutch Butter. A. Kickton. (Zeit. fur Untersuch. der Nahr. und Genussmittel, 1902, v., 458, 459.)-Attention is drawn to the deeirability of applying the phytosterol acetate test (ANALYST, xxvii., p. 94) to Dutch butters which give a low Reichert-Meissl number, and with which the colour tests for cotton and sesame oils yield negative results, before giving a definite opinion 8s to the presence of margarine in the butter. w. P. s. The Polarization of Fruits, Jellies, Jams, and Honey. L. M . Bolman. (Journ. Amer. Chem. Soc., xxiv., 515.)-From his experiments the author comes to the conclusion that the presence of hydrochloric acid increases the lmvo-rotation of an invert sugar solution, and that this explain8 why, when hydrochloric acid is added to a solution of sucrose inverted by boiling with an organic acid, such as occurs in jams and jellies, a slightly higher reading is always obtained.The increase is proportional to the quantity of hydrochloric acid present, and to the amount ofTHE ANALYST. 249 polarization, at any definite temperature. Introducing the correction calculated from his results into the Herzfeld formula, he obtains a - b 141.85 + 0.05b - f S= where S = sucrose, a = direct reading, b = invert reading, T = temperature. The modi- fied formula corresponding to the method used by the Association of Official Agricultural Chemists is a - b 141 *79 + 0.0626 - f S= whilst, to calculate a small amount of cane-sugar in the presence of a large amount of invert sugar, the formula a - [ b - (0,062 x b)] S= 141.79 - f 4 should be used.of glucose. A. G. L. The presence of hydrochloric acid has no effect on the polarization of solutions Valuation of Flour for Bakers’ Use. A. Maurieio. (Landw. Jarhb., 1902, xxxi. , 179 ; through Chem. Zeit. Rep., 1902, 155.)-The author’s experiments show that no opinion as to the suitability of a flour for baking can be based upon an extraction of the gluten, followed by an estimation of its power of rising when tested in an aleurometer, baking oven, or oil-bath. I n general, however, the volume of the bread increases as the volume of the gluten, The quality of the gluten is an important factor ; but, although its valuation, according to the usual practical methods, throws some light upon the quality of the flour for baking, the desirable qualities of the gluten cannot be formulated in precise language.The chemical processes of Bobine and Girard are useless. Neither the amount of extractive matter recovered from gluten or flour, nor the specific gravity of solutions in acetic acid and alcoholic potash indicates the value of a sample to the baker. An estimation of the bulk of the bread or of the experimental cakes made in sheet-metal vessels with maize grits, glass pearls, etc., is of no value because of the different conditions in which they are obtained and of their irregular shapes. The volume of the fermented dough and of the finished bread do not depend upon the absolute quantity of carbon dioxide liberated by the yeast, but upon the power of the dough to retain more or less gas before it sets. Poor flours lose gas during fermentation ; better descriptions hold it until they are placed in the oven.I t would be advantageous if the loss of gas before baking could be avoided ; but, on the other hand, there is a maximum volume for the bread, above which its quality suffers. The fermented doughs of different flours show differences in volume ; but those differences are smaller than such as are given by different sample cakes of the same flour, while the volumes of the doughs do ndt agree with the volumes of the finished cakes. Eermentation tests, accordingly, cannot replae baking tests. The specific gravity of the bread is an excellent criterion for judging of the value of a flour or wheat for bakers’ use.Products of250 THE ANALYST. the best quality have a specific gravity of 0.23 to 0-28 ; medium qualities show 0.35 ; inferior grades give 046 or more. F. H. L. On Specific Sera for Human Blood. Linoseier and Lemoine. ( h a d . de Mbdecine, March 25, 1900; Ann. de Chim. anal., 1902, vii., 185.)-The authors have found that the specific character of the sera obtained by injecting rabbits with human serum (ANALYST, xxvii., p. 194) is not so absolute as has frequently been asserted. According to the results of their experiments the sera are not specific when a too concentrated solution of blood serum is employed, although the precipitate is more pronounced than in the case of the blood of other animals. To avoid this source of error the test should only be applied to dilute solutions.Thus, for example, a solution of normal blood serum containing 1 part in 1,000 invariably gives a reliable reaction with the corresponding prepared serum. C. A. M. The Determination 1902, xv., 519-522.)-For of Aloins in Aloes, E. LQger. (Journ. Pharm. Chim., the isolation of barbaloin, isobarbaloin, and other aloins, the author boiled 500 grammes of the aloes with a mixture of 1,800 C.C. of chloroform and 600 C.C. of methyl alcohol for four hours under a reflux condenser. After settling, the supernatant liquid was decanted and distilled, and the residue taken up with absolute alcohol, from which crystals of aloins separated in three to four days. By this means from 5 to 6 per cent. of barbaloin, free from isobarbaloin, were obtained from Cape aloes, and about the same quantity from Barbedoes aloes- Curagoa aloes yielded about 10 per cent. of aloins, consisting of approximately equal proportions of barbaloin and isobarbaloin. From Jafferabad aloes more than 20 per cent. of aloins, consisting mainly of isobarbaloin, were isolated, whilsia Socotrine aloes gave only about 4 per cent., consisting almost exclusively of barbaloin, with a minute quantity of isobarbaloin. Barbaloin was identified by the character- istics of its chlor-acetyl derivative, which melts at 146.6" C. (corr.), and forms quadratic yellow anhydrous crystals only slightly soluble in hot alcohol, but very soluble in benzene. Isobarbaloin was identified by Klunge's reaction (ANALYST, xxvii., 193), and by its bromine derivative, which is slightly soluble in cold alcohol, from which it crystallizes in yellow needles. Neither of these aloins was found in Natal aloes, which, however, yielded the two analogous compounds--nataloin, and its lower homologue, homonataloin. C. A. M.