716 EXPERIMENT STATTON EECOED. [Vol.36 



Agricultural College. The method is clnimed to yield accurate results and, 

 except for the fact that the copper oxalate must set overnight, is rapid. 



The analysis, purification, and some ckemical properties of agar agar, 

 C. F. Fellers {Jour. Indus, and Engin. Chem., 8 {1916), No. 12, pp. 1128-1133).— 

 The author, at the New Jersey Experiment Stations, discusses and reviews the 

 literature on the sources, preparation, and composition of agar. 



The results of the analysis of 16 samples of agar obtained from widely dif- 

 ferent sources show a remarkable uniformity. Considerably more nitrogen, 

 however, was found in the samples than is usually considered to be present. 

 A percentage ash constituent analysis of three samples is also submitted. A 

 high ash or silica content is considered to be indicative of an inferior product. 



A method of preparing a purified agar is described in detail. It consists 

 essentially of washing the agar shreds in a solution of dilute acetic acid, 

 washing out the acid, and precipitating wliile hot a 5 per cent solution of the 

 agar by means of a large volume of alcohol or acetone. The greater part of 

 the nitrogenous matter is removed by this method, and it is, therefore, recom- 

 mended for the preparation of material to be used in refined bacteriological 

 work, especially where a medium containing a minimum of nutrients is desired. 



" Solutions of agar will solidify at all concentrations of HCl and NaOH 

 between 4.5 per cent H(31 and 5 per cent NaOH. Heating at one atmosphere 

 pressure for 15 minutes in an autoclave nari'ows the range of solidification to 

 from 2 per cent acid to 4.5 per cent alkali. Peptone increases tlie jellifying 

 power of agar. KCl appears to decrease it slightly." The action of some other 

 chemicals on agar is also noted. 



Analytical methods used in sugar chemistry, E. Saillard {Monit. Set., 5. 

 ser., 6 {1916), II, Nos. 897, pp. 193-203; 898, pp. 22^-228) .—This article describes 

 in detail and discusses methods for the determination of the density of sugar 

 beets, sugar in beets by warm aqueous digestion, sugar by Clerget's inversion 

 method, and invert sugar in the presence of saccharose. 



The solubility of calcium sulphite in water and in sug'ar solution, T. van 

 DEB Linden {Meded. Proefstat. Java-Suikerindus., 6 {1916), No. 10, pp. 307- 

 322). — Tabulated solubility data submitted show that calcium sulphite is only 

 slightly soluble in water and 15 per cent saccharose solution, but is more soluble 

 in the latter than in the former. The solubility in either case varies inversely 

 with the temperature. An excess of lime markedly diminishes the solubility in 

 either solvent. 



Data are also submitted on the solubility of calcium sulphite in 15 per cent 

 saccharose plus 1.5 per cent glucose. They do not, however, differ markedly 

 from the solubility figures in the pure saccharose solution. 



The practical significance of such solubility data in sugar manufacture is 

 Indicated. 



Sweet wines of high alcohol content without fortification, W. V. Cruess, 

 E. M. Bkom'n, and F. Flossfedee {Jour. Indtis. and Engin. Chem., 8 {1916), No. 

 12, pp. 1124-1126). — In small-scale fermentations wines of over 18 per cent 

 alcohol were made by the fermentation of grape must with wine yeast and the 

 addition of grape sirup during fermentation. In one of these wines 19.9 per 

 cent alcohol was obtained. The percentages of alcohol thus obtained are con- 

 siderably higher than the maximum obtained by " straight " fermentation with 

 the same yeast, and the higher yields are, therefore, considered to be undoubt- 

 edly due to the addition of the sirup. 



Experiments made to determine the character of the invigorating compound 

 of the sirup showed that it was not the sugar. The substance causing the 

 increased activity of the yeast was not determined. 



Partly dried grapes, used instead of the sirups, yielded the same results. 



