abstracts: chemistry 123 



open to many chances of error, viz., acidity of sample, fineness of sample 

 and time of digestion, changes in sugar content after neutralizing the 

 alkalinity, etc. These are separately treated. 



The method proposed for extraction with the least chances of error is: 

 Boil 12 grams of the finely ground material in a 300 cc. flask with 150 

 cc. of 50 per cent alcohol neutral in reaction for one hour, using a reflux 

 condenser. Complete the volume to 300 cc, after cooling, with 95 per 

 cent alcohol. Transfer 200 cc. to a beaker with a pipette and evaporate 

 on a steam bath to 20 or 30 cc. Transfer this to a 100 cc. flask with water, 

 clarify with a solution of neutral lead acetate, make to volume and 

 filter. Remove the excess of lead, which should be very small, with 

 anhydrous sodium carbonate, filter and determine the reducing sugars 

 in an aliquot portion by one of the usual methods. Invert another por- 

 tion with acid or invertase for the determination of total sugars. 



For accurate work the volume occupied by the original substance 

 must be taken into account. An average for a number of determina- 

 tions shows that 12 grams of such material occupy about 12 cc. and 

 hence the factor of 0.97 must be applied to the results. It is not well to 

 weigh the precipitated cuprous oxide as such as this is often contami- 

 nated with nitrogenous bodies and also mineral matter, but the copper 

 should be determined in it by some such method as Low's. Results 

 are best reported as "Reducing sugars calculated as invert sugar" or 

 "Reducing sugars calculated as dextrose" and "Total sugars by acid 

 inversion calculated as dextrose (or invert sugar, as the case may be)" 

 or "Total sugars by invertase calculated as dextrose (or invert sugar, 

 as the case may be)." 



If sucrose is calculated, it should bear some such wording as "Sucrose 

 calculated from increase of sugars by acid inversion" or "Sucrose cal- 

 culated from increase of sugars by invertase inversion." A. H. B. 



AGRICULTURAL CHEMISTRY.— Translocation of plant food and 

 elaboration of plant material in wheat seedlings. J. A. LeClerc 

 and J. F. Breazeale. Bulletin Bureau of Chemistry No. 138. 

 1911. 



"Wheat was sprinkled upon thin perforated discs of aluminum and 

 placed in pans of water to sprout. Samples of 100 to 200 were with- 

 drawn at regular intervals, the plumule and radicle separated from the 

 rest of the seed and analyses made of both portions. In this way the 

 movement of the organic and inorganic salts from the bran and endo- 



