227 



The true polarization then of a raw sugar, a.- >f other saccharine producis, is a con- 

 ventional arbitrary figure represent!!!'.: tin- sum of the polarizations of the various 

 optical constituents u in It-r certain fixed conditions of temperature.^ -eight of substance, 

 volume of solution, length of tulx-, and quality of liu r ht. If the temperature of polar- 

 i/.ation of a u'iven sii'jar is different from the standard the correction, if correctly 

 applied, must restore the reading obtained upon this same simar under standard con- 

 dition-. Now. the correction advocated by \\'atts and Tempany and that used by the 

 I'nii.-d Staie^ Treasury Department in the Division of Customs will do this for pure 

 M, hut it will not do it for a very large class of raw cane sugars for the reasons 

 already iriven. 



Since the publication >f my previous paper upon this subject I have had occasion to 



study the effect ,,f temperature upon the polarization of many sugars and other cane 



product- and have been more thoroughly convinced than ever of the futility of apply- 



ctioii for the purpose of securing greater concordance in the sacchari- 



metric observations .,f different ch.-n 



The '.'eneral results of this work I have condensed into tabular form, showing the 

 I'olari/at ion and of reducini; sugars for raw cane sugars, and for -e \eral 

 >f ni.i~-.-ciiit.-s and molannnn with the corrections necessary to obtain the polari- 

 x.ation at standard temperature. The theoretical sucrose corrections according to the 

 formula of Watt- and Tciiipany are apjM-nded for purjH>se of comparison The values 

 of the table have been made up fn>m averaged, aome variation was obtained for indi 

 vidual ola-.-e. of raw Hgpl :iple. those of I.oiii-iana which are \er\ hi-h 



in rediK n louer c.-rn-ct imi. It i.- bclie\ed, 



however, that i: D the whole, i- a fair a \erage. 



TuMi jo,- correcting polfriuiwtu ndard temperature. 



[Cornvtlon for nu-h T. :I)M>VI> standard temperatur.-.] 



-,, 



n , 



M 



ta tora 



u,, ,,; 



sa 



,s ... 



n 



Prr crnt. 



I lit I. 141 

 I -. | _1( 



I .1. ; m 



i ... .; *n 

 1 si. I.NI 



\ -> I 10 



' .! 



I .11 7 > 

 7.00 7.80 



7 M> > .4, 



x n i ., 



r. 



> 0.024 



4-aou 



. -. a t 



. I. l.n 



. II ,.,.. 



n in.; 



.1 1.17 



-0.011 



ni 



MAS8ECUITK. 



A 00-10. 00 I -0.016 



U in 14.00 n n.;,, 



[.,.(> is ... o 07 



; .ai 

 Ifl .11 



Is ,,, .1, i,, 



.s i,, n ,,1 



-0.070 



u ,r.x 

 n 11., 



r. 



. n n.;. 

 . u Q90 



. .. m 



MI on 



. n tat 



. n irj:, 



n ir.'l 



n n.-:( 



+ O.M2 



.1, m 



+ 0.014 



.u mo 

 o 0.17 



. n ... 



It will be noted that for very high-grade sugars which polarize over 96 an addition 

 of about 0.03 V. for each C. increase in temperature will practically restore the 

 reading obtained under standard conditions. The percentage of impurities is too 

 small to affect appreciably the temperature correction for sucrose. As the polarization 

 falls below 96 and the percentage of reducing sugars increases, the effect of the tempera- 



