I9I2] ^Alfred P. Lothrop 173 



ing the effects of amylases on the power of starch to imbibe water 

 (prior to hydrolytic cleavage), the writer prepared markedly hydro- 

 phylic starch in the following way: A very thick starch paste was 

 speedily prepared by rapidly pouring a thicl<: potato-starch Suspen- 

 sion through musHn into boiling water while the latter was being 

 vigorously stirred. The vessel containing the paste was inimersed 

 in ice water immediately after the last portion of starch Suspension 

 had been added. By constant stirring of both liquids, and by the 

 maintenance of a low external temperature, the paste was speedily 

 cooled,^'^ when it was poured into, and thoroughly stirred in, a large 

 excess of 95 per cent. alcohol. After the Sedimentation of the prod- 

 uct, and the decantation of the alcoholic liquid, the snow white ma- 

 terial was treated with fresh portions of alcohol until its viscidity 

 disappeared and it became firmly granulär. After several washings 

 with ether, to remove alcohol, the product was rapidly freed from 

 ether in a current of air from an electric fan. Although somewhat 

 hygroscopic, the material formed hard, snow-white masses which 

 could be granulated easily in an ordinary pulverizer. 



Placed in water, the particles swell very rapidly into bloated 

 glassy forms. " Starch paste " may be made almost instantly from 

 the product. The powder can easily be freed from its soluble car- 

 bohydrate impurities by dialysis. The material promises to be of 

 special Service in many connections. Mr. Nathan Rosenthal has 

 undertaken a study of the effects of amylases on the swelling of 

 material of this kind in various anti-hydrophylic media, such as 

 dilute alcohol. 



25. A study of the carbohydrates of the prickly pear and its 

 fruits. R. F. Hare.^^ The difficulties encountered in the practical 

 laboratory Separation of the sugars from the mineral matter, muci- 

 lages, gums and dextrinoid substances have been numerous, and the 

 Operations time-consuming. Many attempts to obtain the sugars 

 free and in crystalline form have usually resulted unsuccessfully; 

 so that it became necessary to make the individual tests not on the 

 sugar crystals, but on the syrups previously purified as much as pos- 

 sible by different methods. 



" The Operations were conducted rapidly in order to prevent undue hydrol- 

 ysis. It is probable that satisfactory results can be obtained by pouring the 

 hot paste directly into alcohol. 



"Hare: Dissertation, Columbia University, 191 1. 



