CHEMISTRY. 



619 



cent of the dry matter of the meat was obtained. The material 

 extracted by the alcohol is not insoluble in ether, but in the author's 

 opinion is intimately mixed with some matter not affected by the ether, 

 but which the alcohol removes. 



The direct determination of calcium carbonate, P. Sestini 

 [Ann. Agron., 23 (1897), No. 7, pp. 326,327). — Digest 5 gm. fine soil in 

 100 cc. of 0.5 per cent acetic acid at the boiling point, in a flask with 

 retlux condenser, until evolution of carbon dioxid is complete (about 1 

 hour). Cool, filter, and evaporate 55 cc. of the filtrate to 5 cc. Add 

 hydrochloric acid (sp. gr. 1.1) and evaporate, repeating the operation 

 until the acetic acid is all driven off and the acetates are converted into 

 chlorids. Dissolve the residue from the evaporation in a small quantity 

 of water, add 10 cc. of ammoniacal ammonium chlorid and makeup to 

 55 cc, with 75 per cent alcohol. Filter to remove calcium sulphate, 

 etc., and precipitate lime in 50 cc. of the filtrate with neutral ammonium 

 carbonate, or, better, ammoniacal oxalate. 



Application of hydrogen peroxid to the analysis of food stuffs, 

 Lebbin (Pharm. Ztg., 17(ls97); abs. in Analyst, 22(1897), Nov., p. 289). — 

 The author calls attention to the solvent power of hydrogen peroxid 

 on starch, and reports some experiments on this. Attempts to estimate 

 starch in this way <h> not appear to have given satisfactory results as 

 yet. The reagent has been found useful in rendering material starch 

 free for microscopical examination, as the appearance of the cellulose 

 structure is unaltered. This has been found serviceable in distinguish- 

 ing wheat flour from rye flour and also in detecting ergot in flour. 



The author's method for the estimation of crude fiber by means of 

 hydrogen peroxid has been described (E. S. E., 8, p. 857). 



The determination of starch in the sweet potato, F. S. Shiver 

 (South Carolina Sta. Bui. 30, pp. 11). — Several well-known methods for 

 determining starch are described and comparative studies with them 

 reported. A volumetric method for the determination of the reduced 

 copper with potassium permanganate was compared with the gravi- 

 metric method, with results " as concordant as could be expected, the 

 difference in the average between the two being only 0.0005 gm. of 

 copper." Comparisons were made on a number of varieties of the 

 sweet potato of the Sachsse method (inversion with acid), the modified 

 Eeinke method (treatment with malt extract without pressure), the 

 Maercker method (treatment with malt extract and heated under pres- 

 sure with tartaric acid), and the Honig method (heating with glycerin). 

 The results of the comparisons are summarized in the following table: 



