Beet-Sugar Making and Its Chemical Control (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1909 edition. Excerpt: ...the Ventzke scale corresponds exactly to 34.68 circular degrees for D at 17.5-C. The graduation of the Ventzke scale and the determination of sugar in impure samples may be summarized as follows: normal sugar solution is made by dissolving 26.048 grams of pure cane-sugar, weighed in air with brass weights, in a 100 c. c. Mohr flask with water at 17-5 C; this, polarised at 17.5 C in a 200 m.m. tube, care being taken to keep the temperature of the (b)-A V N P C 0 A N VH P L Fig. 26.--Optical parts-f saccharimeters. wedge compensation also at 17.5"C, establishes the Ventzke 100 point of the saccharimeter. When 26.048 grams of impure sugar are weighed, dissolved, and polarized under the sa: ne conditions, the Ventzke scale gives directly the percentage of pure sugar present in the substance. Types of Saccharimeters.--There are several types of saccharimeters in use but only the half-shadow types will be presented here as they are the ones most commonly adopted in the sugar laboratories of this country. The arrangement of the essential optical parts is shown in Fig. 26; (a) represents a saccharimeter provided with a Jellett twin prism polarizer, a single wedge compensation, and a Ventzke scale; L indicates the illumination lens; P, the Jellett twin prism polarizer; N, the levo-quartz plate; D, the dextro-wedges; A, the analyzer; O, the objective; C, the ocular; T, the observation tube, (b) shows a saccharimeter provided with a Lippich double field polarizer, a single wedge compensation, and a Ventzke scale; H indicates a half prism; (c), a saccharimeter provided with a Lippich triple field polarizer. Fig. 27 shows a saccharimeter with all the optical parts mounted in their proper places. Costly saccharimeters are provided with a Lippich...