26 



SCIENCE 



[Vol. LV. No. 1410. 



Comparison of the various corn product 

 starches: Chr. E. G. Porst and M. Moskowitz. 

 The Bingham-Green Plastometer is adapted to 

 the examination of various corn starch pastes, 

 alkali, acid and thin boiling (Hersehel and Berg- 

 quist, Journal of Ind. & Bng. Chem., Vol 13, 703). 

 A short review of the derivation of the formulas 

 required is given. Tj'pe curves and tabulated 

 data on the various starches investigated are in- 

 eluded. The effect of the temperature of cook- 

 ing on the properties of the pastes is noted and 

 the need of more accurate formulas suggested. 



An inquiry into fundamentals of sugar col- 

 orimetry: H. H. Peters and P. P. Phelps. 

 The spectrophotometrie investigation of impure 

 sugar products is continued, and the asbestos 

 method of eolorimetric clarification and filtration, 

 which was reported in a previous paper, is further 

 critically examined. Beer's Law is valid for 

 concentrated impure sugar liquors (50 Brix), but 

 dilution with water changes the degree of disper- 

 sion and eolorimetric value of the colloidal non- 

 sugars, invalidating Beer 's Law. A new meth- 

 od, using concentrated granulated syrup of 

 known spectral transmissivity for the dilution of 

 heavily colored, concentrated syrups in place of 

 water is presented. 



The testing of quartz control plates: P. P. 

 Phelps. Quartz control plates are used in pre- 

 cise sugar work to eliminate all errors due to 

 variations in the polariscope itself. All quartz 

 plates sent to the Bureau of Standards are sub- 

 jected to the following tests: (1) Examination 

 of the mounting. (2) Homogeneity of the 

 quartz. (3) Planeness of the faces. (4) Paral- 

 lelism of the faces. (5) "Axis Error." (6) 

 The precise measurement of the rotation from 

 which the sugar value is calculated. A tenta- 

 tive set of specifications for quartz control plates 

 has been drawn up as an aid in the production 

 of plates of uniformly good quality. It is very 

 important that all quartz control plates be stand- 

 ardized at some central agency such as the Bu- 

 reau of Standards. The maker's value, which 

 is stamped upon the mounting, can not be relied 

 upon, in fact, plates have been tested at this 

 bureau whose true sugar value differed from 

 the maker's value by approximate 0.°2 of a sugar 

 degree. 



The origin and development of the cane sugar 

 industry in America: C. A. Browne. The his- 

 tory of plantation cane sugar manufacture in 

 America is briefly sketched with help of lantern 

 slides and old engravings from 1493 down to the 



present day. The evolution of the miU, evapo- 

 rator and other machinery is traced with de- 

 scriptions of such curiosities as Stuart's steam 

 mill and Bessemer 's crusher. The methods of 

 white sugar manufacture in Cuba by means of 

 bone black between 1850 and 1860 are described. 

 In conclusion the origin and development of the 

 modern central system are discussed with particu- 

 lar reference to the future growth of the industry. 



Enzyme method for determination of raffinose 

 in beet sugar-house products: H. S. Paine and 

 P. W. Reynolds. The method of Hudson and 

 Harding, which depends on the hydrolysis of 

 raffinose by invertase with formation of melibiose 

 and fructose, and subsequent hydrolysis of meli- 

 biose by means of the enzj'me melibiase, was 

 adapted for the examination of beet molasses and 

 other sugar-house products. The molasses solu- 

 tion is clarified with basic lead acetate and a 

 small amount of norit, and, after suitable ad- 

 justment of the acidity, top yeast extract, con- 

 taining the enzyme invertase, and bottom yeast 

 extract, containing the enzymes invertase and 

 melibiase, are added to equal portions of the 

 clarified molasses. The difference in the polariza- 

 tions is a measure of the amount of raffinose 

 present. The success of the method depends upon 

 the use of highly purified and concentrated 

 enzyme preparations. 



BQle of fermentation in the deterioration of 

 cane sugar products: C. A. Browne, C. A. Gam- 

 ble, G. H. Hardin and M. H. Wiley. The aver- 

 age quaUtj^ of the raw cane sugar manufactured 

 in the tropics has shown but little improvement 

 during the past five years. Only about 35 per 

 cent, of the Cuban factories make good-keeping 

 sugar of low moisture content. Sugars during 

 deterioration become more hygroscopic, owing to 

 the invert sugar that is formed, and the addi- 

 tional moisture absorbed from the atmosphere 

 accelerates the activity of the destructive micro- 

 organisms. The chief requirements for making a 

 good-keeping sugar are : ( 1 ) Cleanliness in the 

 factory to prevent infection; (2) A moisture 

 content sufficiently low to retard the growth of 

 yeasts, moulds and bacteria; (3) Bagging the 

 sugar after it has cooled to prevent sweating; 

 (4) Storage in clean, dry warehouses in piles 

 that are not high enough to burst the bags. The 

 deterioration of soft refined sugars is less rapid 

 than that of raw cane sugars of the same polar- 

 ization. Sugar cane molasses also undergoes 

 deterioration during storage with destruction of 

 both sucrose and invert sugar. 



