206 EXPEEIMENT STATION RECORD. [Vol.35 



in a water bath at a gradually increasing temperature. Several 25 cc. por- 

 tions of methyl alcohol are added and evaporated to insure dryness. The 

 dry residue is then pulverized in a mortar vrith 25 gm. of anhydrous potassium 

 carbonate, dried 2 hours at 100°, transferred to an S. & S. extraction thimble, 

 extracted from 2 to 3 hours with anhydrous ether in a continuous ex- 

 tractor, and the ether distilled ofE as usual. Any trace of moisture absorbed 

 during the process will contaminate the ether extract with a small amount 

 of water-soluble compounds. To eliminate this error the air-dried extract is 

 washed with several 25 cc portions of water at room temperature, decanted 

 on an ether-extracted filter which is air-dried, and extracted with ether, using 

 the same flask as before. The purified extract is dried from 1 to 1.5 hours 

 in an oven at 100° and considered as unsaponifiable matter. This procedure is 

 not applicable for volatile hydrocarbons or ethereal oils. 



The use of enzyms and special yeasts in carbohydrate analysis, W. A. 

 Davis {Jour. Soc. Ghent. Indus., S5 (1916), No. 4, pp. 201-210, fig. i).— Methods 

 for the determination of saccharose, raffinose, maltose, and starch in plants 

 and their products by means of enzyms are described in detail. On account of 

 the specificity of the enzym action it is indicated that such methods are of 

 especial value in estimating the individual constituents of a complex mixture of 

 carbohydrates. 



On the determination of reducing sugars in the presence of an excess of 

 sucrose, L. Maquenne (Compt. Rend. Acad. Sci. iParis'[, 162 (1916), No. 6, pp. 

 207-213). — The influence of large amounts of sucrose on the determination of 

 reducing sugars has been studied in some detail and the results of the in- 

 vestigation reported. 



The temperature at which the reduction takes place and also the time of 

 heating exercises a marked influence on the results for the reducing sugars. 

 Heating for 10 minutes at 65° C. is recommended as yielding the best results. 

 The quantity of sample used in the analysis is also important. For materials 

 poor in invert sugar 20 gm. samples are recommended. 



The hyposulphite titration has been slightly modified and used with excellent 

 results, especially for very small amounts of copper. The procedure, however, 

 is not applicable in the analysis of molasses and similar materials which con- 

 tain substances that absorb iodin. For such material the copper oxid must be 

 determined either gravimetrically or by some other volumetric procedure. 



An apparatus for digesting crude fiber, J. M. Pickel (Jour. Indus, and 

 Engin. Chem., 8 (1916), No. 4, pp. S66, 367, figs. 2).— A simple form of condenser 

 for use in crude fiber determinations which is easy to manipulate is described 

 in detail. The form and construction of the condenser obviates the use of all 

 rubber connections. It can be made of zinc, copper, or even glass. In the 

 latter case an ordinary glass flask provided with a suitable side tube in its 

 neck is quite satisfactory. 



A furnace for crude fiber incineration, J. M. Pickel (Jour. Indus, and 

 Engin. Chem., 8 (1916), No. 4, pp. 367, fig. 1). — An inexpensive and easily con- 

 structed furnace for use in crude fiber determinations is described in detail. 

 It consists of a piece of asbestos board with a circular opening upon which 

 is set a disk of wroxight iron. An asbestos cylinder, specially prepared, is 

 placed around the iron disk and is covered with a piece of asbestos board of 

 the same dimensions as that of the base, having a small hole in its center. The 

 lieat is supplied by a small Bunsen burner. 



The analysis of maple products. — VII, The electrical conductivity test for 

 purity of maple sirup, J. F. Snell (Jour. Indus, and Engin. Chem., 8 (1916), 

 No. 4, pp. 351-333 ) . — Revised directions for the conductivity test of maple sirup 

 previously noted (E. S. R., 31, p. 610) are submitted. 



