=99. Application of the Process.=—In practice the process of inversion is used chiefly in the analysis of molasses and low grade massecuites. In approximately pure sugars the direct polarization is sufficiently accurate for all practical purposes. In molasses resulting from the manufacture of beet sugar are often found considerable quantities of raffinose, and the inversion process has been adapted to that character of samples. In molasses, in sugar cane factories, the disturbing factors are chiefly invert sugars and gums. The processes used for molasses will be given in another paragraph. In certain determinations of lactose the process of inversion is also practiced, but in this case the lactose is converted into dextrose and galactose, and the factors of calculation are altogether different. The process has also been adapted by McElroy and Bigelow to the determination of sucrose in presence of lactose, and this method will be described further on. In general the process of inversion is applicable to the determination of sucrose in all mixtures of other optically active bodies, which are not affected by the methods of inversion employed. =100. Determination of Sucrose and Raffinose.=—Raffinose is a sugar which often occurs in beets, and is found chiefly in the molasses after the chief part of the sucrose has been removed by crystallization. It is also found in many seeds, notably in those of the cotton plant. In a pure solution of sucrose and raffinose, both sugars may be determined by the inversion method of Creydt.[63] The inversion is effected by means of hydrochloric acid in the manner described by Clerget. The following formulas are calculated for a temperature of observation of 20°, and the readings should be made as near that temperature as possible. _C_ - 0.493_A_ (1) _S_ = -------------- 0.827 _A_ - _S_ 6 (2) _R_ = --------- = 1.017_A_ - ------. 1.57 1.298 In these formulas _S_ and _R_ are the respective per cents of sucrose and raffinose desired, _A_ the polarization in sugar degrees before inversion, _B_ the polarization after inversion read at 20°, and _C_ is the algebraic difference between _A_ and _B_. It must be understood that these formulas are applicable only to a solution containing no other optically active substances, save sucrose and raffinose.