806 EXPERIMENT STATION RECORD. 



reduces Fehling's solution, which points to the presence of the functional alde- 

 hyde or ketone group in the molecule." 



Suggestions in regard to the possible atomic grouping of the above are ap- 

 pended. 



Action of hydrogen chlorid upon diastase, I, T. Panzer (Hoppe-Seyler's 

 Ztschr. Physiol. Chem., 82 {1912), No. 3-^, pp. 216-325; ahs. in CcntU. Bakt. 

 [e/c], 2. AM., 37 (1913), No. 11-13, p. 281).— After studying the effects of dry 

 hydrogen chlorid gas upon diastase, the author concludes that a chemical com- 

 bination of the ferment and gas is necessary for amyloclastic activity. 



Action of hydrogen chlorid upon invertase, II, T. Panzer ( Hoppe-Seyler's 

 Ztschr. Physiol. Chem., 82 (1912), No. 5, pp. 377-390; ahs. in Centbl. Bakt. 

 [etcl, 2. Aht., 37 (1913), No. 11-13, p. 28i).— Invertase absorbs much hydrogen 

 chlorid but loses its activity as a result. There is probably a difference be- 

 tween the chemical constitution of diastase and invertase. 



Saccharifying diastase of malt and the reaction of the medium, H. Van 

 Laer (Orig. Commiin. 8. Internat. Cong. Appl. Chem. [Washington and Neiv 

 York'i, U (1912), Sect. Vlb, pp. 203-213) .—This is a study of the influence of 

 various amounts of acid and alkali on diastase obtained from malt extracts of 

 different kinds. 



The inhibition produced by an excess of eitlier an acid or an alkali is 

 deemed due to the formation of an inactive compound between the enzym and 

 the acid or alkali. The loss in acidity in the presence of hydrogen ions and 

 hydroxyl ions is due to three principal causes, (1) the destruction of a part of 

 the euzym which is not reversible, (2) the temporary mobilization of a portion 

 of the enzym, and (3) an increase in the activity caused by a loss in ions and 

 due to the influence of stabilization. 



Book of methods (Methodenhuch. Vienna, 1913, pp. XVI+307, figs. 9).— 

 This is the first edition of a treatise on methods compiled by the Association of 

 Austrian Experiment Stations. The methods are for soils (general and spe- 

 cial methods), moor soils, artificial fertilizers, peat straw and peat mull, com- 

 mercial feeding stuffs, feed lime, condition powders, seeds, fats, waxes, oils 

 and varnishes, cane sugar, molasses, sugar beets, bone charcoal, starch, alcohol, 

 wine residues, sulphur, water, sewage, vegetable tanning materials, and foods. 



Winkler's method for the determination of carbon dioxid in water, J. 

 Casares and S. Pina ve Rt-bies (Ann. Chini. Analyt., 18 (1913), No. 4, pp. 

 133-136; abs. in Chem. Abs., 7 (1913), No. 19, p. 3377).— In these experiments, 

 which were made with pure sodium carbonate in solution, an average error of 

 2.5 per cent was noted. This was about six times the error found by the origi- 

 nator of the method. The results were inconstant even with identical amoimts 

 of sodium carbonate, and the error did not depend upon the amount of hydrogen 

 passed through the apparatus. It increased rapidly as the amount of carbon 

 dioxid decreased. 



Colorimetric determination of small amounts of manganese in drinking 

 water, E. Schowalter (Ztschr. Untersuch. Nahr. it. Genussmth, 26 (1913), No. 

 2, pp. lO.'i-lOS). — When estimating manganese by conversion into permanganate 

 with nitric acid and ammonium persulphate it is of importance first to remove 

 any chlorids which may be present. This is done by the addition of silver 

 nitrate, but the turbidity produced interferes with the subsequent colorimetric 

 estimation. It is not possible to remove the hydrochloric acid by heating the 

 water with sulphuric acid and ammonium persulphate. 



Silver nitrate seems to be active in the reaction when permanganate is being 

 formed and consequently the author prefers the following procedure for deter- 

 mining manganese: One hundred cc. of water is evaporated with 10 cc. of 



