COLLEGE OF PHARMACY 
 
"* 
 
THE POLARISCOPE IN THE 
 CHEMICAL LABORATORY 
 
THE POLARISCOPE 
 
 IN THE 
 
 CHEMICAL LABORATORY 
 
 AN INTRODUCTION TO POLARIMETRY AND 
 RELATED METHODS 
 
 BY 
 
 GEORGE WILLIAM ROLFE, A.M. 
 
 INSTRUCTOR IN SUGAR ANALYSIS IN THE MASSACHUSETTS INSTITUTE 
 OF TECHNOLOGY 
 
 California College of Pharmacy 
 
 g 0rfe 
 THE MACMILLAN COMPANY 
 
 LONDON: MACMILLAN & CO., LTD. 
 1919 
 
 *Q 
 
 All rights \rtserved 
 
COPYRIGHT, 1905, 
 BY THE MACMILLAN COMPANY. 
 
 Set up and electrotypcd. Published September, 1905. 
 
 J. S. Gushing & Co. Berwick <fe Smith Co. 
 Norwood, Mass., U.S.A. 
 
PREFACE 
 
 THE immense importance of the sugar industry in world 
 economics has forced the development of the polariscope 
 into a sugar-testing instrument of high efficiency. Com- 
 paratively few practicing chemists are familiar with any 
 other application of this useful laboratory tool. 
 
 Many books have been written on commercial saccha- 
 rimetry, but it is only by hunting through the whole mass 
 of literature of analytic chemistry that occasional instances 
 can be found of the application of the polariscope in 
 general laboratory practice. 
 
 Landolt's great work is the only one devoted to a com- 
 plete treatment of the subject of polarimetry, but that is, 
 in the main, a book for the physical chemist and trained 
 investigator in pure science. 
 
 Hence I have ventured to write a simple introductory 
 treatise, not a complete manual of polarimetry by any 
 means, but one explaining in an elementary way funda- 
 mental principles and their application in general labora- 
 tory practice. 
 
 Naturally, I have devoted much space to methods in use 
 in sugar manufacture, but have also described those used in 
 brewing, the starch industries, and food and drug analy- 
 sis as well. It has seemed best to introduce outlines of 
 some technical processes and factory methods of chemical 
 control to make the subject clearer. I have also over- 
 stepped the strict bounds of polarimetry to explain methods 
 obviously accessory to many determinations. 
 
 v 4; 
 
vi PREFACE 
 
 A sketch of the use of the polariscope in pure science is 
 given in view of the great possibilities of the instrument in 
 that field. 
 
 In short, with an experience covering nearly twenty 
 years as technical chemist in the sugarhouses of the 
 West Indies, in the glucose industry of the West, and as 
 a teacher of polarimetric methods in a great technical 
 school I offer the book in the hope that it may prove a 
 guide to a better comprehension of the polariscope as a 
 practical laboratory tool, and suggest means of wider 
 application. 
 
 I can make but small return here in acknowledging 
 my indebtedness to those who have kindly assisted me 
 in the preparation of these pages, to my father, Dr. 
 W. J. Rolfe, whose criticism and advice has been an 
 inestimable aid in putting this book through the press; 
 to Professor F. H. Storer, an esteemed critic, but more 
 than all, one whose kindly interest and encouragement 
 have greatly heartened me in my task ; to my colleagues, 
 Professors Wendell, Noyes, Gill, Mulliken, Mr. A. G. 
 Woodman, and others who have aided me with advice 
 and criticism in their special fields of work. 
 
CONTENTS 
 
 PAGE 
 
 FUNDAMENTAL PRINCIPLES i 
 
 THE POLARISCOPE 15 
 
 THE SACCHARIMETER 28 
 
 ACCURACY OF SACCHARIMETER MEASUREMENTS ... 39 
 GENERAL NOTES ON APPARATUS AND LABORATORY MANIPU- 
 LATION ... .48 
 
 NOTES APPLYING TO SPECIAL INSTRUMENTS .... 68 
 POLARIZATION OF CANE SUGAR GENERAL COMMERCIAL 
 
 METHODS 87 
 
 DETERMINATION OF SUCROSE IN PRESENCE OF OTHER OP- 
 TICALLY ACTIVE SUBSTANCES (DOUBLE POLARIZATION) . 101 
 
 SUGARHOUSE AND REFINERY METHODS Ill 
 
 CHEMICAL METHODS OF DETERMINING SUGARS . . .160 
 
 STARCH AND STARCH PRODUCTS 173 
 
 MISCELLANEOUS SACCHARINE PRODUCTS 222 
 
 APPLICATION OF THE POLARISCOPE IN SCIENTIFIC RESEARCH . 238 
 APPLICATION OF THE POLARISCOPE TO CHEMICAL ANALYSIS 
 
 OTHER THAN CARBOHYDRATE DETERMINATIONS . . 260 
 
 APPENDIX 279 
 
 TABLES 285 
 
 INDEX , . . . 315 
 
THE POLARISCOPE IN THE 
 CHEMICAL LABORATORY 
 
 FUNDAMENTAL PRINCIPLES 
 
 The Function and Scope of Optical Analysis. The 
 methods of analysis to be described are based on the 
 behavior of " polarized light " in passing through sugar 
 solutions. In many cases these methods can.be applied 
 as well to other " optically active " compounds that are in 
 the liquid state or in solution. Many organic substances 
 show optical activity about seven hundred have been 
 studied: hydrocarbons, such as diamyl; alcohols, as 
 dichlorhydrin ; acids, like tartaric ; alkaloids, as nicotine ; 
 essential oils, as oil of lemon ; and terpenes, like camphor. 
 
 Comparatively little is known about the relationship of 
 optical activity to the chemical and physical structure of 
 matter. Pasteur, about 1850, pointed out that the optical 
 behavior of solutions of isomeric forms of tartaric acid 
 could be foretold by a study of the planes on the crystals 
 of these acids. This relation has been found to hold true 
 in case of other' organic crystals. An analogous law had 
 been discovered in quartz crystals by Herschel, in 1835. 
 Van't Hoff and Le Bel, in 1874, showed that differences 
 in the optical activity of isomers could be explained by 
 a peculiar molecular structure and demonstrated by the 
 graphic symbolism ordinarily used in interpreting organic 
 
2 FUNDAMENTAL PRINCIPLES 
 
 reactions. 1 This theory has been useful in predicting the 
 existence of many organic compounds, and may be said 
 to form the basis of the scheme of Fischer's masterly 
 researches on the sugars. 2 
 
 While it is not the province of this book to go into 
 an elaborate exposition of the properties and theories of 
 polarized light, it is necessary, for the intelligent use of 
 apparatus and the understanding of methods, to describe 
 a few simple experiments, with brief explanations. 
 
 Double Refraction. "Iceland spar," a crystallized cal- 
 cium carbonate, which in the natural mineral readily splits 
 up into colorless rhombohedrons, is the customary material 
 used in optical instruments for producing plane polarized 
 light. Looking through such a rhombohedron of Iceland 
 spar in any direction (except parallel to a line joining 
 the two most obtuse solid angles, known as its "optical 
 axis ") it will be noticed that the images of objects are 
 doubled. Evidently the light passing through the crystal 
 follows two paths. This "double refraction" is character- 
 istic of any crystal not " isometric " in structure, but any 
 transparent solid, ordinarily not doubly refractive, glass for 
 instance, will show double refraction if different parts are 
 subjected to unequal pressure, thus producing variations 
 of density. 
 
 The Nicol Prism. In a substance showing double re- 
 fraction, each member of the divided beam in its passage 
 
 1 A review of the work of Pasteur and bibliography of original papers 
 will be found in Landolt's " Das optische Drehungsvermogen," p. 40. A 
 similar review of the work of Van't Hoff and Le Bel begins on p. 43 of the 
 same work. Pasteur's original paper has also been recently published in the 
 " Alembic Club Reprint," No. 14. 
 
 2 Outlined by Tollens, " Handbuch der Kohlenhydrate," II, 1 1-40. 
 
FUNDAMENTAL PRINCIPLES 
 
 through the crystal has undergone a remarkable change, 
 known as " polarization," which makes it available in sugar 
 analysis. To utilize this property it is necessary to isolate 
 one of these beams, which can be done by a " Nicol prism," 
 so called from its inventor. 
 
 Such a prism is made from a rhomboidal piece of Ice- 
 land spar, one whose length is approximately three times 
 its breadth, by grinding and polishing the end faces so that 
 they make an angle of 68 with the long edges instead of 
 the 71 of the original crystal, and cutting the crystal in 
 halves along a plane passing through one of the most 
 
 OF UNPOLARIZED 
 a UGHT 
 .CEMENT JOINT 
 
 FIG. i. DIAGRAM SHOWING PATHS OF LIGHT RAYS IN A NICOL PRISM. 
 
 obtuse solid angles of the prism 90 to the modified end 
 faces. The cut surfaces are polished, and cemented 
 together with Canada balsam, restoring the two parts of 
 the crystal to their original positions. The long side 
 faces of the prism are blackened. 
 
 Any ray of light on entering a Nicol prism in a direction 
 parallel to the long edges is divided into two components. 
 The component most refracted, known in this case as the 
 " ordinary ray," meets the balsam sheet at such an angle 
 that it is totally reflected, and practically all absorbed by 
 the dark coating of the sides of the prism. The other ray, 
 called the "extraordinary," striking the balsam plane at a 
 
4 FUNDAMENTAL PRINCIPLES 
 
 lesser angle, passes through the prism, emerging in a con- 
 dition which is known as "plane polarized/' 1 
 
 Properties of Plane Polarized Light. Looking through 
 two Nicol prisms at any source of light, holding the prisms 
 so that the light will pass through each successively, and 
 revolving one slowly on its long axis, that is, around the 
 line of direction of the light beam, it will be noticed 
 that the light seen through the prisms varies continu- 
 ally as the prism turns. At certain points in the revo- 
 lution of the prism, 180 apart, no light passes, while at 
 exactly midway between these positions (90 from them) 
 most light is seen. As the prism is revolved, the light 
 increases up to a maximum, and then decreases till the 
 point of " total extinction " is reached. Hence, the amount 
 of light passing through such a combination of Nicol 
 prisms in the manner described depends on the angle 
 through which one of the prisms is rotated from the 
 positions giving maximum or minimum illumination. The 
 relative positions of the Nicols giving maximum light 
 intensity will be found to be that point of rotation when 
 the rhomboids of the end faces are parallel, each edge of 
 the end face of one prism to the corresponding edge of the 
 other prism. When one of the Nicols is rotated to a posi- 
 tion 90, no light passes, and the field is dark. In the first 
 case, the prisms are said to be "parallel," in the second 
 "crossed." 
 
 Polariscope. If the combination of prisms as described 
 is held in some suitable apparatus, one prism being fixed, 
 the other capable of rotation, a measuring device can be 
 
 1 Some modified forms of the Nicol, designed to increase its light capacity, 
 are described in Landolt's work already referred to. 
 
FUNDAMENTAL PRINCIPLES 5 
 
 attached to the rotating prism and these phases of light 
 intensity, or light effects depending on them, can be re- 
 ferred to definite points on a scale. Such an instrument 
 is called a " polariscope," and can be utilized in sugar 
 analysis. A sugar solution, placed between the prisms in 
 such a way that the light passes through it in its passage 
 between the prisms, affects' the intensity of the light, so that 
 it will be necessary to rotate jthe movable prism to restore 
 any light effect shown by the polariscope previous to the 
 insertion of the solution. The magnitude of the angle 
 through which the prism must be rotated to restore the 
 original light effect is found to depend directly on the con- 
 centration of the sugar solution, and therefore can be taken 
 as a measure of the sugar itself. 
 
 Undulatory Theory. The so-called " undulatory " or 
 "wave" theory has proved indispensable for interpreting 
 these phenomena of polarized light. In its simplest form 
 this theory assumes that all light rays are caused by waves 
 of energy transmitted in straight lilies through a medium, 
 called " ether," which pervades all space, even dense 
 solids. 
 
 The transmission of energy in transverse waves propa- 
 gated in straight lines can be admirably illustrated by 
 means of a stretched elastic cord. If one end of such a 
 cord is vibrated transversely by shaking it at right angles 
 to the direction in which the cord is stretched, waves will 
 pass along the cord, as each particle is successively set in 
 oscillation. Obviously it is the disturbance that travels as 
 a wave and not the matter in the cord itself, each particle 
 of which is merely oscillating backward and forward. If 
 the cord is continuously shaken in different directions 
 
6 FUNDAMENTAL PRINCIPLES 
 
 transverse to its length, it illustrates well the theoretical 
 conception of ordinary light. 
 
 The direction in which the cord is stretched is the 
 straight line which determines the path of transmission of 
 the waves and corresponds to the light ray. The particles, 
 always oscillating transversely, but whose planes of vibra- 
 tion are continually changing their position in space, 
 illustrate the ether. 
 
 For such a series of transverse waves see the diagram. 
 Two particles moving in the same direction at the same 
 time, such as A and B t are said to be in the " same phase.'* 
 
 FIG. 2. 
 
 When the displacement and motion of the two vibrating 
 particles are exactly opposite, as A and C, they are said to 
 be in " opposite phase." A " wave length " is the distance 
 along the line of transmission between the two nearest 
 particles in the same phase, as from A to B. The distance 
 from one particle to the next in opposite phase is half a 
 wave length. A ray, representing the direction of trans- 
 mission (path), of the energy is a geometric line and hence 
 has but one dimension. A multitude of rays having a 
 common direction is called a "beam," and can be con- 
 sidered to occupy space. These terms are also loosely 
 used by many writers on optics to express the waves of 
 energy themselves which are moving in a ray or beam. 
 
 The color of the light depends on the period of vibration 
 of its waves. In the passage of the light through any 
 homogeneous medium, as air, its color bears a direct 
 
FUNDAMENTAL PRINCIPLES 7 
 
 relation to its wave length. Light consisting of waves of 
 one length is said to be "homogeneous'* or " monochro- 
 matic," its color being expressed mathematically in terms 
 of its wave length when passing through air. Light 
 made up of vibrations of many wave lengths is said to 
 be " compound " ; ordinary day or lamplight is of this 
 nature. 
 
 [See Preston's " Theory of Light " for a full explanation 
 of wave propagation and exposition of the undulatory theory 
 in its application to optics.] 
 
 Reverting to the phenomena observed with the two 
 Nicols : when light enters a Nicol prism, owing to the 
 molecular structure of the calc-spar, the ether is prevented 
 from vibrating in varying planes, its oscillations being con- 
 fined to two at right angles to each other. Application 
 of the law of resolution of motions will greatly assist in 
 understanding the theoretical explanation of these light 
 phenomena. Many of the effects of Nicol prisms can be 
 made clear by making a diagram of the vibration planes 
 according to the doctrine of the " parallelogram of forces." 
 
 In the Nicol prism, the theory shows that the planes of 
 vibration of the two light beams are determined by the 
 diagonals of the end faces. It has been shown how one of 
 these beams has been disposed of by total reflection. The 
 plane of vibration of the unextinguished (emerging) beam 
 is parallel to a plane passing through the shorter diagonals 
 of the end faces of the prism. A plane at right angles to 
 this is known as the " plane of polarization." The rays of 
 the emerging beam from a Nicol prism, after emergence, 
 continue to vibrate only in the definite vibration plane, 
 determined by the position of the shorter diagonals of the 
 
8 FUNDAMENTAL PRINCIPLES 
 
 end faces of the prism, and are not, like ordinary light, 
 continually changing their vibration planes. It is this 
 characteristic of the light which distinguishes it, in the 
 interpretation of the theory, as " plane polarized." 
 
 In the combination of the two Nicols as described, the 
 plane polarized beam emerging from the first Nicol, having 
 one resultant vibration plane, passes into the second Nicol, 
 where it is in general resolved into two plane polarized 
 beams, one of which is reflected out. The amount (inten- 
 sity) of light which will pass through the second prism can 
 be determined when the angle which its vibration plane 
 makes with that of the first prism is known, by making a 
 diagram of the positions of the vibration planes of the 
 emerging beams of the two Nicols as follows : 
 
 Let AB represent the vibration plane of the light emerg- 
 ing from the first Nicol (which is known as 
 _ the " P olarizer ")> and AD that of the emerg- 
 
 *~ S* " ing beam from the Nicol nearest the eye (the 
 FIG. 3. 
 
 "analyzer"), this latter plane making the 
 
 angle a with the plane of the polarizer. 
 
 The beam defined by AB is divided, on entering the 
 second Nicol, into two components whose vibration planes 
 are AD and AC, of which only the beam defined by AD 
 can emerge from the analyzer. Its intensity as compared 
 with the light passing through the polarizer is represented 
 
 AD 
 by - , the relative lengths of AD and AB being deter- 
 
 mined by completing the parallelogram ACBD. 
 
 When the Nicols are crossed (that is, when AB is per- 
 pendicular to AD\ it will be seen that the light emerging 
 from the polarizer is passing along a vibration plane in 
 
FUNDAMENTAL PRINCIPLES 9 
 
 such a position that the waves are totally reflected by the 
 analyzer, and the field is black, or, in actual experiment, 
 of minimum intensity, since usually not quite all the rays 
 entering the prisms are parallel. 
 
 It is true that this assumption of light waves is purely a 
 theoretical one. It is equally true that scientists guided 
 by these ideas have made actual laboratory measurement? 
 which logically seem to represent light-wave measurements. 
 Reference will be made to some of these values, which are 
 actualities of physics, whatever their interpretation. 
 
 Effect of Sugar Solutions on Polarized Light. (i) If the 
 light passing through a polariscope is of one wave length, 
 that is, "homogeneous" or " monochromatic," as is, prac- 
 tically, the yellow light made by vaporizing table salt in a 
 Bunsen burner, and a tube filled with sugar solution is placed 
 between the two Nicols, so that the light passing from one 
 prism to the other has to traverse the length of the tube 
 through the solution, the following results will appear : 
 if the Nicols are crossed, total extinction does not now 
 occur, but the extinction point now will be found by rotating 
 the analyzer to the right (in the direction of the motion of 
 the hands of a clock). 
 
 (2) If the light is ordinary daylight or lamplight, that 
 is, white light, made up of light of all wave lengths (" com- 
 pound light"), it will be seen that extinction does not take 
 place at any position of the analyzer, but the field of view- 
 is colored, all the spectral colors appearing as the analyzei 
 is rotated. 
 
 The explanation of these light effects is that the planes 
 of vibration of the light waves of different lengths are 
 rotated to the right by the sugar solution, but not all to 
 
10 FUNDAMENTAL PRINCIPLES 
 
 the same extent ; those of the shortest length, namely the 
 violet, being turned the most, the red the least. 
 
 At each position of the rotating Nicol the planes of 
 vibration of some of the rays, those of some definite tint 
 (wave length), make an angle of 90 with the principal 
 section of the analyzer, and are consequently reflected and 
 absorbed. The light emerging from the analyzer is, there- 
 fore, the original light deprived of the color of these reflected 
 rays, or " complementary " to them. In the case where the 
 light is monochromatic, as is, practically, the sodium flame, 
 total extinction occurs when the rotating Nicol is turned so 
 that its vibration plane is at right angles to the rotated 
 plane of vibration of the beam passing into it from the 
 sugar solution. But one such plane exists, as all the rays 
 having a common wave length are rotated alike. 
 
 It follows that if the rotatory effect of a sugar solution 
 on plane polarized light is to be measured, it is necessary 
 to use monochromatic light. 
 
 This behavior of the sugar solution is called its " optical 
 activity." Any optically active substance in solution will 
 affect plane polarized light in a similar way, rotating the 
 planes of vibration to the right in some cases, to the left in 
 others. Substances rotating to the right are known as 
 " dextrorotatory " (symbolized +); those to the left, "levo- 
 rotatory" ( ). 
 
 Laws governing Rotation of Optically Active Substances. 
 In the experiment just described, when the light is 
 monochromatic, the angle of rotation of the vibration plane 
 of the plane polarized light by a sugar solution can be 
 measured by the angle through which the analyzer of the 
 polariscope must be turned to restore the original light 
 
FUNDAMENTAL PRINCIPLES II 
 
 effect given by the instrument previous to placing the 
 sugar solution between the prisms (in the case described, 
 total extinction). This can be demonstrated by means of 
 a diagram analogous to Fig. 3. 
 
 The stronger the sugar solution and the longer the 
 column through which the light passes, the greater the 
 angle through which the vibration plane is turned. Ex- 
 periment has shown that, for rays of any one wave length, 
 this rotation is directly proportional to the concentration and 
 length of column of the solution. 
 
 Specific Rotatory Power. When the angles of rotation 
 of different optically active substances are compared under 
 identical conditions of concentration, column length, and 
 light, each substance gives a characteristic value. When 
 determined under standard conditions, the characteristic 
 angle obtained is a measure of the " specific rotatory power " 
 or " specific rotation " of the substance, and is symbolized 
 by the Greek letter alpha (a). In modern measurements, 
 the specific rotation of solutions of optically active sub- 
 stances is measured by the angle of rotation, expressed in 
 angular degrees, which plane polarized light, corresponding 
 in wave length to that of the yellow, D, line of the solar 
 spectrum} undergoes in passing through, at a temperature 
 
 1 As there are two lines given by sodium light, D\ and Z> 2 (the latter much 
 brighter), in the most exact measurements the ray midway between the two 
 spectrum lines is taken as the standard, having a wave length of .00058932 
 millimeter. Such light, according to Landolt, is produced from a sodium 
 chloride flame after passing the rays successively through solutions of potas- 
 sium bichromate and uranium sulphate. 
 
 The light of the D lines of the solar spectrum separated by spectroscopic 
 methods has a resultant wave length or " optical centre " of .00038925 milli- 
 meter and gives rotation values identical within the usual limit of the measure- 
 ments with those taken by the Lippich filtered sodium light. 
 
12 FUNDAMENTAL PRINCIPLES 
 
 of 20 C. y a decimeter column of a solution of the optically 
 active substance having a concentration of one gram in one 
 cubic centimeter. This can be expressed by the following 
 equation: a==a ^ (l) 
 
 where a is the angle of rotation in degrees, I the length of 
 column in decimeters, and c the concentration. If there 
 are w grams of substance in v cubic centimeters of solution, 
 
 the concentration can be expressed as ~ 
 
 v 
 
 Hence, a = , (2) 
 
 V 
 
 and ._. (3) 
 
 By this last equation, the specific rotatory power of any 
 optically active substance can be calculated from solutions 
 of any convenient concentration if the column length is 
 known. As will be seen later, effects so obtained in many 
 cases have to be corrected for influence of solvent and tem- 
 perature, but for cane sugar these effects are practically 
 negligible for ordinary conditions of analysis. These spe- 
 cific rotation values are the fundamental constants of all 
 calculations in optical analysis, being analogous in their 
 use to the atomic weights in the usual computations of 
 gravimetric and volumetric analysis. 
 
 If the concentration of a solution is expressed in per- 
 centage of substance in solution (grams in 100 grams), as 
 is often the case in commercial analysis, equations (2) and 
 (3) are expressed somewhat differently. The number of 
 grams in 100 grams can be expressed as /, and since, if d 
 
 represents the density of the solution, v = ^ -, .*. = 
 
 d v 100 
 
FUNDAMENTAL PRINCIPLES 13 
 
 Hence, ^ 
 
 'fir (5 > 
 
 Obviously it is necessary to distinguish carefully be 
 tween these two expressions of concentration, in order to 
 avoid serious confusion in calculations. 1 
 
 Yellow light, corresponding to the D line of the solar 
 spectrum, has been adopted for the standard because of 
 the ease with which light of this color can be produced by 
 volatilizing table salt in a Bunsen burner, alcohol lamp, or 
 other source of hot non-luminous flame. Specific rotations 
 so determined are more exactly symbolized [a]/, to dis- 
 tinguish them from others to be referred to. 
 
 In the case of an optically active substance which is 
 itself a liquid, as, for instance, spirits of turpentine, the 
 specific rotatory power is expressed by the equation 
 
 -ar 
 
 where d is the density of the liquid. 
 
 In the case of an optically active transparent solid, as 
 
 quartz, a = -, the unit for / being a section one millimeter 
 
 / 
 
 thick cut in a plane at right angles to the optic axis. The 
 standard temperature for all specific rotations is 20 C. 
 
 1 In very accurate determinations of specific rotation the concentration is 
 expressed in percentage of substance in solution, both substance and solvent 
 being weighed and all weights being absolute, that is, calculated for weighings 
 in a vacuum. In the case of the weight of a solid substance of the density of 
 cane sugar the difference between the weighings in air and the absolute is 
 only .06%. 
 
14 FUNDAMENTAL PRINCIPLES 
 
 Application of the Laws of Optical Rotation to Sugar 
 Analysis. The application of these laws to the analysis 
 of sugar or other optically active substance can now readily 
 be understood. Let P be the per cent of optically active 
 substance contained in w r grams of sample, the weight of 
 this optically active substance being w. 
 
 Then, P= , P being expressed decimally. 
 From the fundamental equation already given : 
 
 av 
 
 w = - 
 a/ 
 
 T-U D av 
 
 Then, />= . 
 
 a/ze/ 
 
 For example, 17.50 grams of raw sugar in water solution, 
 made up to 100 cubic centimeters, observed in a 2-deci- 
 meter tube, rotated the plane polarized yellow ray 21 35'. 
 Taking the specific rotation of cane sugar as 66.5 and 
 expressing all values in standard units, the percentage of 
 cane sugar can be expressed as follows : 
 
 2158X100. = ! (Aat . 92.7%). 
 
 2X66.5X17.50 
 
 If the substance has its rotation constant appreciably 
 affected by the amount of solvent present, as is the case 
 with camphor or tartaric acid, the calculation will be more 
 complicated. Under the ordinary conditions of commer- 
 cial sugar analysis, this influence is so small as to be negli- 
 gible, as already stated. 
 
 1 Throughout this discussion it is, of course, assumed that but one optically 
 active substance is present in solution. 
 
THE POLARISCOPE 
 
 Essential Parts. From the preceding chapter it is 
 clear that the essential parts of a polariscope for meas- 
 uring the rotatory effects of optically active substances are 
 two Nicol prisms, one of which must be capable of rota- 
 tion and have some suitable device for measuring the angle 
 of its rotation from a definite position. These prisms 
 must be arranged, as previously described, in a suitable 
 holder, so that tubes containing solutions to be examined 
 can be placed between the prisms, and finally there must 
 be some source of monochromatic light. 
 
 As a rule the analyzer is the rotating prism, as this 
 brings the measuring scale conveniently near the eye of 
 the observer. 
 
 In 1840 Biot introduced a polariscope of this descrip- 
 tion, using the total extinction position of the prisms for 
 the end point ; but, as experiment with such an instrument 
 will show, it was impossible to determine the exact point 
 of extinction without a large error. In the optical devices 
 for producing a more precise end point, much ingenuity 
 has been expended ; in fact, these devices alone determine 
 the essential differences between most of the different 
 makes of polariscopes for measuring angles of rotation 
 directly. 
 
 Mitscherlich Polariscope. Mitscherlich, in 1844, im- 
 proved the original instrument of Biot, so that a broad 
 
 '5 
 
i6 
 
 THE POLARISCOPE 
 
 black band in a light 
 field was produced at the 
 extinction point, instead 
 of total darkness. The 
 Mitscherlich polariscope 
 is still used for compar- 
 atively rough measure- 
 ments, being sensitive 
 to .1. 
 
 The Transition-tint 
 Polariscope. Another 
 end-point device, used 
 in the earlier instruments 
 ,by Biot arid others, 
 was the "transition-tint" 
 quartz plate. Sections 
 of quartz, cut perpen- 
 dicular to the optic axis 
 of the crystal, have a 
 strong rotatory effect 
 on plane polarized light 
 when the light passes 
 parallel to the optic axis, 
 some crystals turning 
 the plane of polarization 
 to the right (clockwise), 
 others to the left. The 
 direction in which the 
 planes of vibration ro- 
 tate can be predicted by 
 a study of the arrange- 
 
THE POLARISCOPE . 17 
 
 ment of the faces of the original crystal. The amount of 
 rotation is independent of the right or left .direction, but 
 depends on the thickness of the quartz section. A milli- 
 meter section of quartz, according to Biot, rotates plane 
 polarized light of different colors about as follows : 
 
 Red, 19* Yellow, 24 Green, 28 Violet, 41 
 
 These values are for "mean" rays, or those approxi- 
 mately in the middle of the spectrum bands of the colors 
 mentioned, and do not apply to the " Fraunhofer '" lines as 
 do the more exact measurements of later observers. 1 
 
 The transition-tint plate consists of two quartz sections, 
 cut ^s described, of equal thickness, but of opposite rota- 
 tions. These are mounted in a diaphragm opening be- 
 tween the polarizer and analyzer, in such a way that each 
 , section covers half of the optical field of the polariscope. 
 The sections are cut 3.75 millimeters thick, and rotate the 
 mean yellow rays 90 (3.75 X 24 = 90), which in conse- 
 quence cannot pass through the analyzer when its plane 
 of polarization is parallel l to that of the polarizer. White, 
 or any light containing rays of all wave lengths, as lamp 
 or gas light, in passing through such an optical combina- 
 tion will be deprived of its yellow rays, and the optical 
 field will show, accordingly, the resulting "complement- 
 ary" tint, usually described as a rose violet. If the 
 analyzer is turned in the least, contrasting tints of red and 
 blue are seen in opposite halves of the field. Only at the 
 end point, or at a position of the analyzer 180 from it, do 
 
 1 A section cut any odd multiple of 3.75 millimeters in thickness will pro- 
 duct the same effect. When the plate is cut an even multiple, it is easily 
 demonstrated that the transition tint appears when the Nicols are crossed. 
 c 
 
1 8 THE POLARISCOPE 
 
 both halves of the field show the same tint, this rose- 
 violet transition tint. 
 
 The transition-tint polariscope was introduced by Robi- 
 quet, and was much used by earlier investigators, as it was 
 more sensitive than the Mitscherlich, and had the advan- 
 tage of using ordinary light. 
 
 Inasmuch as this instrument gave measurements of the 
 rotation of the vibration plane of the mean yellow ray, 
 and not that of the D line of the sodium flame, it gave rise 
 to statements of rotation figures on a different standard, 
 which is distinguished by the symbol [a] ; -, the mean yel- 
 low ray of wave length .0005608 millimeter, being known 
 as the/ ray (French jaune, yellow). 
 
 The transition-tint polariscope is not now used in scien- 
 tific measurements, although the transition-tint plate is the 
 end-point device of some modern saccharimeters. The 
 instrument has many disadvantages. Colored solutions 
 obviously interfere with its readings. Many colorless solu- 
 tions of high rotation produce dispersive disturbances 
 which prevent an even-tinted field at the end point. It 
 has been objected to on the ground that lights of different 
 wave-length composition, such as daylight and gaslight, give 
 slightly different complementary tints. The instrument is 
 of course useless to those who are color-blind. A cheap 
 form of this polariscope is used in Europe somewhat for 
 determining sugar in wines, as the errors of such low 
 rotations are inconsiderable. 
 
 The transition-tint polariscope which must not be con- 
 founded with the Soleil saccharimeter is of importance 
 to the modern investigator solely because the optical con- 
 stants which were obtained by its measurements are still 
 
THE POLARISCOPE 19 
 
 found in many modern works, especially English, and con- 
 sequently the difference between specific rotatory powers 
 expressed by [a]/> and [a]^ should be understood. Inas- 
 much as the rotation for the D line of the spectrum by a 
 millimeter section of quartz is 21.7, that of the mean yel- 
 low being 24, as previously stated, the old transition-tint 
 constants can be changed to the modern standard by the 
 
 factor, iii^.i 
 24.0 
 
 Practically all modern polariscopes use the sodium light, 
 and have some device which shows a blank, evenly 
 illuminated field at the end point, while at any other posi- 
 tion of the analyzer,- a part of the field, usually one half, is 
 shaded. One of the earliest of these " shadow " or " half- 
 shade " polariscopes was devised by Jellet about 1860. 
 Cornu and Duboscq improved the instrument in some 
 details of its construction. 
 
 The Duboscq Half -shade Rotatometer. The end-point 
 device of the Duboscq half-shade "rotatometer," as it is 
 called, is the Jellet-Cornu or " split " prism, which takes the 
 place of the ordinary polarizer. This is made by bisecting 
 a Nicol prism, or one of its sections, lengthwise of the 
 
 1 Some confusion has resulted from the introduction by Montgolfier in 1874 
 of a jaune moyen ray, having a rotation value of 24.5 for the quartz milli- 
 meter plate, subsequently adopted by Landolt in his book on the polariscope 
 as the value for the j measurements. This ray is not the Biot ray, inter- 
 mediate in wave-length value between the sodium and thallium lines of the 
 solar spectrum and having a wave length of .0005608 millimeter, but is the 
 ray of a wave length .0005553 of a rotation value for the quartz millimeter 
 plate which is the arithmetical mean between the rotation values for the D ray 
 and the E ray. This later change of standard was most unfortunate, as it has 
 caused a misunderstanding which has marred much excellent work by early 
 investigators [/. Chem. Soc., 1897 (71), 89]. 
 
20 THE POLARISCOPE 
 
 prism, in the plane passing through the shorter diagonals of 
 the end faces. Equal wedge-shaped sections are taken off 
 the two cut surfaces, and the two parts are cemented to- 
 gether again. The effect of the removal of the two wedge- 
 shaped sections is to tilt the polarizing planes of the two 
 halves of the prism so that they make an angle (usually 
 about 1/5) with each other. This type of prism is made 
 in several ways, but the principle is the same in every form. 
 This modified prism is used as a polarizer, and is mounted 
 in the polariscope with a diaphragm having a circular open- 
 ing between it and the analyzer in such a way that the 
 opening is bisected vertically by the line of the joint of the 
 two halves of the prism. If the analyser is turned to a 
 position which would give total extinction for an instrument 
 fitted with an ordinary Nicol for a polarizer, the field made 
 by the diaphragm opening will not be black in this case, 
 \>\& faintly and evenly illuminated, appearing as a luminous 
 disk. The slightest rotation of the analyzer from this posi- 
 tion produces a shading in one or the other halves of the 
 field. This can be made clear by a discussion of the follow- 
 ing diagram : 
 
 Let AC and FG respectively represent the positions of 
 the planes of polarization of the analyzer and polarizer of 
 a polariscope equipped with ordinary Nicol prisms adjusted 
 
THE POLARISCOPE 21 
 
 for total extinction, A C being at right angles to FG. If a 
 Jellet-Cornu prism is substituted for the Nicol prism polar- 
 izer, but placed in the same relative position as the latter, 
 the plane of polarization of the polarizer will no longer be 
 represented by the line FG, but can be by the broken line 
 DEEB, if DE and EB represent the respective positions of 
 he planes of each half of the prism. In the position of 
 Jie polarizer assumed, these planes make equal angles, 
 DEA and BE A, with the plane of the analyzer AC. 
 
 Consequently, as these angles are also less than a right 
 angle, the optical field defined by the circle which repre- 
 sents the diaphragm opening will appear evenly but faintly 
 illumined. 
 
 If the analyzer is rotated, its plane of polarization AC will 
 approach a right angle with one of the polarizing planes 
 DE or EB, and a shadow will appear in the corresponding 
 half of the field. Thus there is only one position of the 
 analyzer, within 180, where both halves of the field appear 
 evenly illuminated, and from which position the slightest 
 rotation of the analyzer gives a shadow in one half of the 
 field or the other. This is the true end point. It is 
 true that the intermediate positions at 90 give a (bright) 
 evenly illumined field, but no shadows appear on slightly 
 rotating the analyzer, as is evident from a study of the 
 diagram. 
 
 The Duboscq rotatometer is an accurate and sensitive 
 instrument, and can be used with any kind of homogeneous 
 light. Formerly it was much used in France. The diagram 
 also shows that, the nearer the angle of the tilting of the 
 planes of polarization of the two halves of the prism to 
 1 80, the more sensitive is the polariscope to small angles 
 
22 THE POLARISCOPE 
 
 of rotation ; but, on the other hand, the field is darker at 
 the end point. This indicates the most serious disadvantage 
 of this type of polariscope, as it is impossible to make one 
 instrument that will be applicable for universal laboratory 
 measurements. If the polariscope has a prism giving suf- 
 ficient precision for scientific work, it will not pass light 
 enough at the end point for polarizing the dark-colored solu- 
 tions often met with in commercial practice, molasses for 
 instance. 
 
 Laurent Polariscope. This need for a half-shade polari- 
 scope, having an end-point device by which the angle of 
 the polarizing planes of the two halves of the field could 
 be varied to suit the requirements of the work, was met in 
 a most ingenious and satisfactory manner by Laurent in 
 1877. 
 
 The Laurent polariscope has the ordinary Nicol prisms 
 for polarizer and analyzer, mounted in the usual way, except 
 that the polarizer is so arranged that it can be rocked or 
 rotated on its long axis through a small angle. The char- 
 acteristic end-point device is a thin plate of quartz cut par- 
 allel to the optic axis of the crystal. A section so cut is 
 doubly refractive, dividing a light beam entering normal to 
 its surface into two component beams with vibration planes 
 respectively perpendicular and parallel to the optic axis. 
 The thickness of the section is such that, when sodium 
 light is used, the component ray vibrating at right angles 
 to the optic axis, on emerging, has its vibrations accelerated 1 
 half a wave length in its passage through the quartz. This 
 
 1 The undulatory theory shows that the difference in refraction of the two 
 polarized rays is the result of a difference in speed of transmission of the light 
 waves, the less refracted ray being transmitted more rapidly. 
 
THE POLARISCOPE 
 
 quartz plate covers one half of the circular opening of a 
 diaphragm which defines the optical field of the instru- 
 ment, and through which the light passes from polarizer 
 to analyzer. Therefore the quartz intercepts these rays in 
 one half of the field. 
 
 The following diagram will assist the explanation : Let 
 AB represent the vibration plane as well as the amplitude 
 of vibration of the light from the polarizer which makes a 
 small angle BA C with the s 
 
 optic axis of the quartz 
 plate, this axis being repre- 
 sented for convenience as 
 parallel to the edge AC of 
 the quartz plate bisecting 
 the circle representing the 
 diaphragm opening. When 
 the light from the polarizer 
 reaches the quartz, it is 
 resolved into two compo- 
 nents A C and AF, parallel 
 and perpendicular to the 
 optic axis. The light of the component AF travels faster 
 through the quartz than that of the component A C vibra- 
 ting parallel to the axis, and, having gained on AC half 
 a wave length, is at time of emergence from the quartz in 
 just the opposite phase of vibration, relative to AC, to its 
 original phase on entering the quartz. Consequently, this 
 emerging component can be represented by the line AE 
 equal to AF, but opposite in direction. By means of the 
 parallelogram AEGC it can be shown that the components 
 AE and AC can be compounded into the resultant AG, as 
 
 FIG. 6. 
 
24 THE POLARISCOPE 
 
 if the light had come from a polarizer having its vibration 
 plane inclined to the optic axis of the quartz at an angle 
 GAC equal and symmetrical to the angle BAG actually 
 made by the plane of the polarizer with the optic axis. So 
 too the angles made by these planes with that of the ana 
 lyzer are equal and symmetrical, when it is adjusted sc 
 that its vibration plane is perpendicular to the optic axis of 
 the quartz, and hence the intensity of the light in both 
 halves of the field is the same, the absorption and reflec- 
 tion caused by the quartz being negligible. Thus, the 
 polarizer and the quartz plate together give the effect of a 
 Jellet-Cornu prism, the planes of which are tilted to each 
 other in each half of the field by a small angle ; but have the 
 valuable advantage that this angle can be varied at will by 
 means of the rocking polarizer without disturbing the end- 
 point adjustment of the analyzer, since the angles made by 
 the vibration planes of the light in each half of the field with 
 the analyzer plane always remain equal and symmetrical 
 whatever their magnitude. In all other respects, the ex- 
 planation of the light effects of the Jellet-Cornu prism 
 polariscope applies to the Laurent instrument, so need not 
 be enlarged upon here. 
 
 The Laurent polariscope is the one most generally used 
 in direct laboratory measurements of optical rotation, and 
 is the standard instrument used by the French govern 
 ment in testing sugars. Its use is obviously restricted to 
 sodium light. The average error of measurement is stated 
 by Landolt to be .2 per cent, due to mechanical imperfec- 
 tions inseparable from its construction. First-class French 
 instruments certainly show agreement within an error con- 
 siderably less than .2 per cent. 
 
THE POLARISCOPE 2$ 
 
 Lippich Polariscope. The Lippich polariscope, which is 
 specially made for most precise measurements of optical 
 rotation, uses a small Nicol for its shadow device, which is 
 placed between the polarizer and the analyzer, close to the 
 former, and covers half of the field, being mounted in an 
 analogous manner to the Laurent quartz plate. The po- 
 larizer is mounted so that its plane of polarization makes 
 a slight angle with that of the small Nicol, which latter is 
 known as the "half prism." This angle can be varied at 
 will by a device which permits the polarizer to be moved 
 axially, an index showing the exact position of its plane of 
 polarization relative to that of the half prism. 
 
 This instrument is said to be free from the errors believed 
 to be inherent in the construction of the Laurent polari- 
 scope, and can be used to measure rotations of homo- 
 geneous light of any wave length. It has the disadvantage 
 that the angle of the shadow device cannot be changed 
 without altering the end-point adjustment of the analyzer. 
 The Lippich polariscope is often constructed with great 
 elaboration and nicety of adjustment, and is capable of 
 measurements to .001 with a mean error, according to 
 Landolt, of i$ u or about .004. By means of a double 
 prism end-point device, the field can be divided into three 
 parts. It is estimated that the eye can distinguish the 
 shadow change in a triple-field instrument with twice the 
 precision, or to 8". These very precise instruments are 
 used only in the most exact physical measurements. 1 
 In ordinary laboratory work polariscopes are used which 
 
 1 For complete descriptions of these polariscopes, see Landolt's " Das op- 
 tische Drehungsvermogen." See also my remarks on triple-shade saccha- 
 rimeters. 
 
26 THE POLARISCOPE 
 
 measure to i', or, with the more modern decimal scale, 
 .01. 
 
 In using the Lippich polariscope it is necessary that the 
 condensing lenses for illuminating the field be adjusted 
 with the greatest care to insure even illumination without 
 surface reflections. The instrument also seems to be 
 much more sensitive to extraneous light than is the Lau- 
 rent polariscope. 
 
 Wild Polariscope (?Polaristrobometer"\ The Wild po- 
 laristrobometer, invented in 1864, has for its end-point 
 device a " Savart polariscope," which consists of two calc- 
 spar plates cut at 45 to the optical axis of the crystal and 
 placed with their vibration planes at right angles to each 
 other 1 and at 45 to that of the analyzer, which is fixed, 
 the polarizer being the rotating prism. The effect of this 
 combination is to produce " interference bands" or black 
 horizontal stripes in the field when homogeneous light is 
 used. These bands disappear in the centre of the field at 
 points 90 apart in the rotation of the polarizer. The 
 exact point of disappearance of these bands, as shown by a 
 blank space symmetrically placed relative to two cross 
 hairs in the field, is taken as the end point. The displace- 
 ment of this blank spot in the field is very marked for a 
 slight rotation of the polarizer. 
 
 As it is the polarizer that rotates, its rotation is in the 
 reverse sense to the rotation of the plane of polariza- 
 tion by the optically active substance ; that is, dextrorota- 
 tory substances, for instance, have their rotatory effects 
 measured by a corresponding rotation of the polarizer to 
 the left. 
 
 1 Wild, "Ueber ein neues Polaristrobometer," Berne, 1865. 
 
THE POLARISCOPE 27 
 
 The Wild instrument has not been popular in the 
 United States, owing to the unusual end point and the 
 awkwardness of manipulation. It is, however, for a prac- 
 ticed observer, sensitive and precise enough for most labo- 
 ratory measurements. 
 
THE SACCHARI METER 
 
 General Principles. As the value of the polariscope for 
 the determination of sugar (sucrose) had quick recognition 
 in commercial work, instruments were soon specially de- 
 signed to give the sugar content of industrial products by 
 a simpler, more direct way than by the use of the ordi- 
 nary laboratory polariscope. Such instruments, known 
 as " saccharimeters," have scales graduated in divisions 
 expressing per cents of sugar instead of angular degrees, 
 and the manipulation of testing is so conducted that the 
 saccharimeter gives a direct reading of the sugar per cent 
 of the sample without calculation. 
 
 The theory of the graduation of a saccharimeter is very 
 simple. As the optical rotation is directly proportional to 
 the concentration of the optically active solution and the 
 tube-length, it is clear that if the weight of sugar sample 
 taken for polarization, the volume of aqueous solution in 
 which this weight of sample is dissolved, and the tube-length 
 are constants, the sole variable effect on the rotation (leav- 
 ing out of consideration the slight influence of temperature 
 and concentration on the specific rotation) will be caused 
 by the difference in the amount of sugar in the sample. 
 Further, if the constant weight of sample taken for polari- 
 zation is that weight of pure sugar which will give a read- 
 ing of 100 divisions of the saccharimeter scale, the reading 
 
 28 
 
THE SACCHARIMETER 29 
 
 when this weight of any sample of sugar is polarized will 
 directly express the per cent of sugar in the sample. This 
 weight is known as the " normal weight" of the saccha- 
 rimeter. 
 
 It is necessarily assumed that no other optically active 
 substance than sugar (sucrose) is present in the sample. 
 
 The most convenient values for tube-length and volume, 
 universally adopted in saccharimetry, are 2 decimeters and 
 100 cubic centimeters. The standard commercial saccha- 
 rimeter in this country and abroad, except in France, has 
 a normal weight of 26.048 grams. 
 
 Originally, a different standard of graduation was used, 
 and it still prevails in the rotary saccharimeters, which 
 were the earliest type. On this account it may be profit- 
 able to show the origin of these standards of graduation. 
 The angular-degree graduation is not suited for a saccha- 
 rimeter scale, as simple calculation will show. By the 
 
 aij 
 
 formula, w=, derived from the fundamental equation 
 cu 
 
 expressing optical rotation, making a : 100, /:2, ^:ioo, 
 and taking [a]/> of sucrose in aqueous solution as 66.50: 
 
 100 x 100 
 w = = 75.2 grams of sugar as the normal weight 
 
 DO. 5X2 
 
 for the angular-degree scale. This is an impracticable 
 amount of sugar to dissolve in 100 cubic centimeters of 
 water at ordinary laboratory temperature. The saccha- 
 rimeter graduation consequently requiring a smaller rota- 
 tion value for its 100 point, a convenient constant was 
 found in the specific rotation of quartz, that is, that caused 
 on the D ray by a millimeter section of right-rotating quartz 
 cut perpendicular to its optic axis. This value as originally 
 
3<D THE SACCHARIMETER 
 
 determined was 21.667 at l 7-5 C. for light obtained by 
 vaporizing sodium chloride in a Bunsen burner and using 
 as a ray filter a section of potassium bichromate crystal. 
 The normal weight of sugar found by the equation given 
 above for the commercial standard of volume and tube- 
 length is 16.29 grams. 
 
 When the sugar is dissolved in 100 " reputed" or Mohr 
 cubic centimeters on a temperature standard of 17.5 C., 
 as is the custom in commercial work, the normal weight is 
 16.32, owing to the volume of the Mohr flask being .23 
 per cent greater than the " true " cubic centimeter flask. 1 
 This will be discussed later. 
 
 The Laurent and Duboscq rotatory polariscopes are pro- 
 vided with saccharimetric scales of this graduation, in addi- 
 tion to their angular degree scales. The Wild polariscope 
 
 1 Much misapprehension prevails as to the exact value of the normal weight 
 of the Laurent saccharimeter. This is partly due to the existence of instru- 
 ments standardized for a normal weight of 16.19 grams, and partly to the fact 
 that the specific rotation of quartz has been redetermined by instruments using 
 light of a different wave length than that used for the ordinary laboratory type 
 of Laurent polariscope. 
 
 No light obtained from a sodium flame by the ordinary methods is " opti- 
 cally pure," of one definite wave length, but contains light of many wave 
 lengths differing by but small values from that of the two D rays, which are 
 themselves obviously of two different wave lengths. 
 
 Such light acts like absolutely homogeneous light of a wave length corre- 
 sponding to a ray which represents the resultant intensity of these diverse rays, 
 its wave length being called by the Germans the " Schwerpunkt" or "centre 
 of gravity " of the light. The " optical centre of gravity " of the light used 
 in the later measurements of quartz differed from that used in the Laurent 
 polariscope, and apparently has given rotations about .2 per cent larger. 
 
 Evidently, a normal weight of sugar calculated on the rotation value of 
 a millimeter section of quartz would be higher also in the same ratio. 
 
 As a matter of fact, the normal weight of the standard Laurent saccharim- 
 eter has been a fixed value for years, being actually that weight of sugar 
 which, dissolved under standard conditions of concentration and tube-length, 
 
THE SACCHARIMETER 31 
 
 has an additional saccharimetric scale divided into 400 
 divisions, 100 of which correspond to 10 grams of sugar 
 dissolved in 100 cubic centimeters. 
 
 Quartz-wedge Saccharimeters. General Principles. In 
 commercial work, where many rapid polarizations have to 
 be made, the sodium light is inconvenient to maintain and 
 trying to the eyesight. At the same time, owing to the 
 unequal rotation dispersion of the rays of different wave 
 length, it is impracticable to use the saccharimeter with 
 rotating analyzer, and measure the rotation of the polarized 
 light directly, if the light used is white or of a compound 
 nature. This has been explained in the chapter on Funda- 
 mental Principles. 
 
 The problem of devising a saccharimeter for use with 
 ordinary lamp or day light was solved most ingeniously by 
 the quartz-wedge compensator, invented in 1848 by Soleil, 
 who found that the rotatory effect of sugar solutions could 
 be exactly neutralized by a plate of left-rotating quartz of 
 appropriate thickness. The kind of light has no influence, 
 as, owing to the fact that the dispersive power of quartz 
 and sugar in water solution are practically the same (that 
 is, the planes of polarized light of different wave lengths 
 are turned in the same proportion by sugar solutions and 
 quartz), the plane of polarization of each ray is brought 
 
 gives a rotation of 21 40' (21.667) to tne ravs of a sodium chloride flame 
 filtered through a section of potassium bichromate crystal. Whether this rota- 
 tion value is the accepted one for the specific rotation of quartz or not is 
 immaterial for accuracy in saccharimetry, or even for rotation measurements, 
 if, in the latter case, the wave-length value of the optical centre of the light is 
 known. Apparently, there have been no wave-length determinations of the 
 optical centre of light as actually used by the Laurent saccharimeter in sugar 
 testing. 
 
 The earlier saccharimeters of Duboscq used a normal weight of 16.35 grams. 
 
32 THE SACCHARIMETER 
 
 back to the same angular position which it had before 
 being rotated by the sugar solution. 1 
 
 Hence, for any concentration of solution there is a cor- 
 responding thickness of left-rotating quartz which will just 
 neutralize (compensate for) the rotatory effect of the sugar. 
 The Soleil quartz-wedge compensator is a device for intro- 
 ducing at will what is in effect a section of left-rotating 
 quartz of the desired thickness between the polarizer and 
 analyzer. 
 
 The diagram, shown as a plan, will explain the compen- 
 sator and its working. AB represents the line of trans- 
 c mission of the light through 
 
 the instrument along its axis, 
 the analyzer being at A and the 
 polarizer at B. C and D are 
 B two wedges of right-rotating 
 quartz with parallel sides which 
 are movable by being slid past 
 each other in a direction at 
 FlG 7< right angles to the axis of the 
 
 instrument (AB). Together, 
 
 these two wedges make a section with parallel sides, at 
 right angles to AB, of a thickness which can be varied at 
 will by moving one or both of the wedges. 
 
 E is a section of left-rotating quartz. When the com- 
 bined thickness of C and D equals that of E, the opposite 
 rotating effects of the two wedges and the section E bal- 
 ance, and the scale of the saccharimeter attached to the 
 wedges reads zero. If, however, a tube of sugar solution 
 is placed in the instrument between the polarizer and the 
 
 1 See table of the comparative rotatory dispersion of quartz and sugar solu- 
 tion in Landolt (p. 133). 
 
THE SACCHARIMETER 33 
 
 compensating device, it will be necessary to decrease the 
 thickness of the right-rotating section made by the wedges 
 by sliding them by each other outward till the left-rota- 
 tory effect of the section E balances the combined effect 
 of C, D y and the sugar solution. If the 100 point of the 
 wedge scale shows the position of the wedges to compen- 
 sate for the rotary effect of the normal weight of pure 
 sugar polarized under standard conditions, then the per- 
 centage purity of any sample will be given by the scale 
 reading if the usual procedure is followed. 
 
 The Soleil-Duboscq Saccharimeter. About 1850, Du- 
 boscq was the first to make a practical quartz-wedge sac- 
 charimeter for commercial testing. The Soleil-Duboscq 
 saccharimeter uses the transition-tint quartz plate already 
 described for its end-point device, and practically elimi- 
 nates the disturbing effects of colored solutions by what is 
 known as the " sensitive tint producer," an attachment for 
 producing light of the color desired to overcome the dis- 
 turbing tint of any highly colored solution by combination 
 or interference. It consists merely of a third Nicol prism, 
 ranged to be rotated, and placed between the eyepiece and 
 the analyzer. Between these two prisms is a section of 
 quartz cut perpendicular to its optic axis. By rotating this 
 tint-producing prism, any tint desired can be made in the 
 field. This effect is produced in the passage of the light 
 from the analyzer of the saccharimeter, which latter in this 
 case acts as a polarizer relative to the prism of the tint 
 producer, and is in accord with principles already explained 
 in describing the sensitive plate in a previous chapter. 
 Obviously the tint device must be adjusted for each colored 
 solution polarized. 
 
34 THE SACCHARIMETER 
 
 The tint is so chosen as to make a background for show- 
 ing to best advantage the color change in the transition- 
 tint plate, so that very delicate variations in color in either 
 half of the field can be noted with precision. The tint 
 device in no way affects the measurement of the sugar 
 solution, since this obviously is made through adjustment 
 of the position of the quartz wedges compensating for rota- 
 tions which take place between the two fixed Nicols, the 
 polarizer and analyzer of the saccharimeter. 
 
 17 D 
 
 FIG. 8. DIAGRAM OF OPTICAL PARTS OF SOLEIL-DUBOSCQ SACCHARIMETER 
 (eyepiece and condenser lenses not shown). 
 
 A . Analyzer. S. Position of tube of sugar solution. 
 
 P. Polarizer. RQ. Rotating Nicol and quartz in eyepiece, 
 
 CC. Quartz compensator. for producing sensitive tints. 
 
 T. Transition-tint plate. 
 
 The normal weight of the Soleil-Duboscq saccharimeter 
 is based on the rotation value of the millimeter section of 
 quartz, but is usually given as 16.35 grams instead of 
 16.32. 
 
 The Soleil-Ventzke-Scheibler Saccharimeter. The nor- 
 mal weight of 16.3 grams of sugar does not give a solution 
 of sufficient concentration to show variations in tint, in 
 measurements on the Duboscq-Soleil saccharimeter, for the 
 ordinary observer to distinguish with precision differences 
 corresponding to .1 per cent of sugar in the sample, and 
 as this was demanded by modern commercial requirements, 
 an improved instrument was designed by Scheibler, which 
 used the graduation of Ventzke, the 100 point being at the 
 position of compensation for a sugar solution of the density 
 
THE SACCHARIMETER 35 
 
 of i.iooo at 17.5 referred to water at 17,5. This stand- 
 ard has been more conveniently expressed as equivalent 
 to 26.048 grams of sugar, weighed in air, and made up to a 
 solution of 100 Mohr cubic centimeters at 17.5, and gives 
 .026 grams for producing a change of .1 per cent of the 
 scale, instead of .016 of the old standard, quite sufficient to 
 make a distinguishable change in tint at the end point. 
 Scheibler also improved the quartz-wedge saccharimeter in 
 many details of design, greatly increasing its practical 
 efficiency. 
 
 While the modern transition-tint saccharimeter, the 
 Soleil-Ventzke-Scheibler, as it is formally designated, is a 
 precise instrument in the hands of trained observers, and 
 still much used, it has been largely replaced in the past few 
 years by the shadow saccharimeter ; for, as already noted, 
 any transition-tint instrument is useless to the color-blind, 
 and requires much more practice to read with precision. 
 
 The Schmidt and Hansch Half-shade Saccharimeter. - 
 This differs from the modern transition -tint instrument in 
 using the Jellet-Cornu prism for an end-point device. 
 Consequently, the observer determines the end point by an 
 equality of shade instead of tint. This type represents the 
 best modern saccharimeter. With such an instrument, 
 using ordinary artificial light, the intensity being much 
 greater than the sodium flame, the objections to the Jellet- 
 Cornu prism, mentioned in describing the Duboscq (rota- 
 tory) polariscope, do not apply, as the prism can be cut to 
 give sufficient precision without impairing the illumination 
 too greatly. 1 
 
 1 Some of the most recent instruments of Schmidt and Hansch use the 
 Lippich double-shade polarizer and an improved arrangement of illuminating 
 
36 THE SACCHARIMETER 
 
 The Triple-shade Saccharimeter. The triple-shade de~ 
 vice of the Lippich polariscope, recently applied to quartz- 
 wedge saccharimeters, is becoming popular, as it gives 
 according to some authorities a more precise end point (to 
 .03 per cent), but it considerably complicates the instru- 
 ment, and is liable to get out of adjustment. It is doubtful 
 whether usual conditions permit this greater precision to 
 be of avail. Moreover, an expert can easily read the half- 
 shade type to .03 per cent. 1 
 
 Peters Saccharimeter. The Peters instrument with the 
 Lippich shade device differs in the main from the Schmidt 
 and Hansch 2 in the mounting, which is designed for great 
 stability and rigidity. In the latest instruments the wedges 
 are inclosed in a dust-proof box which also mitigates the 
 effect of sudden temperature variations. The pinion for 
 moving the wedges is lengthened so that the observer can 
 move it with his hand resting on the table, a small detail 
 which greatly adds to the comfort of manipulation. 
 
 Instead of the ivory scales used in the earlier instru- 
 ments, both the Schmidt and the Peters saccharimeters 
 are now fitted with scales of an alloy known as "nickelin," 
 
 lens as recommended by Landolt (" Das optische Drehungsvermogen," p. 344). 
 These instruments have an improved form of compensator devised by Martens 
 {Zeits. lustrum., 20, 82), consisting of two quartz wedges corresponding to C 
 and D of Fig. 7, but of opposite rotations. On the shorter fixed wedge (Z?) 
 is cemented a prism of glass, of the same dispersion as quartz, which serves to 
 keep the rays in alignment with the optical axis of the instrument. The ad 
 vantages gained are less loss of light by absorption and a saving of one quart, 
 section, which is a consideration of some importance, as there is hardly an 
 adequate supply of quartz sufficiently optically pure to meet the demand fo* 
 saccharimeters. 
 
 1 By " per cent " is meant the scale division corresponding to a per cent. 
 
 2 Schmidt and Hansch have adopted this form of mounting in some of their 
 newer saccharimeters. 
 
THE SACCHARIMETER 37 
 
 which is unaffected by moisture and so little by tempera- 
 ture as to make any change in the divisions negligible. 1 
 
 The Double- wedge Saccharimeter. The compensation 
 system of these saccharimeters has both quartz sections 
 made variable by sliding wedge devices. The wedges are 
 arranged as in the diagram. 
 
 A and B are right-rotating quartz wedges, corresponding 
 to those in the ordinary single-wedge instrument ; Cand D 
 are the left-rotating quartz wedges. B and Care movable, 
 
 B C 
 
 A 
 
 FIG. 9. 
 
 the first known as the "working wedge," the second as the 
 "control wedge." Both pairs of wedges are provided with 
 scales of equal saccharimetric value. 
 
 In ordinary use of the saccharimeter, the control wedge 
 is set at zero, and the working wedge is used in the ordi- 
 nary manner for making saccharimetric measurements. 
 On removing the tube of sugar solution, the control wedge 
 can be used to check the readings, because if compensa- 
 tion is now made by moving this wedge, without disturb- 
 ing the working wedge from the setting for the reading 
 first taken, both wedges will give equal readings. So, 
 too, when no rotating solution is in the instrument, the 
 end point will be obtained when both wedges have the 
 
 1 Fric uses a milk-glass scale illuminator for making the metal graduations 
 clearer. Some recent instruments have the graduations engraved on the 
 quart/, of the compensator itself. 
 
38 THE SACCHARIMETER 
 
 same readings at any point of the scale. The double- 
 wedge compensation, consequently, enables the readings 
 of the saccharimeter to be checked throughout the scale, 
 as well as giving a check on the observation itself. 
 
 The greater complication and expense of the double- 
 wedge saccharimeter prevents its general use. 
 
 FIG. 10. RECENT TYPE OF PETERS DOUBLE-WEDGE HALF-SHADE 
 SACCHARIMETER. 
 
 RK, Reflecting device for illuminating scale. 
 
 G> Box inclosing wedge compensator. 
 
ACCURACY OF SACCHARIMETER 
 MEASUREMENTS 
 
 Weight. Taking the limit of error of commercial labo- 
 ratory measurements as .1 per cent, it is clear that, as no 
 saccharimeter in general use has a normal weight of less 
 than 16 grams, weighings to .005 gram are certainly suffi- 
 ciently precise. The most appropriate balance for weigh- 
 ing sugar samples is a quickly working balance of the 
 necessary sensitiveness only. Indeed, the use of an ana- 
 lytical balance of high precision often leads to more inac- 
 curate readings, as many commercial samples contain so 
 much moisture that the loss by evaporation is considerable 
 if the weighing is prolonged. 
 
 Tube-length. An accuracy of length to .1 millimeter 
 is obviously sufficient for all ordinary laboratory measure- 
 ments where the 2-decimeter tube is used. Tubes of stand- 
 ard makes rarely show errors of length as great as this. 
 
 Volume. The cubic centimeter, according to the abso- 
 lute metric standard, is defined with sufficient exactness 
 as equivalent to the volume occupied by i gram of water 
 weighed in vacuo at the temperature of maximum density, 
 4 C. 1 Some saccharimeters are graduated for a normal 
 weight of 26.048 grams of sugar dissolved in 100 true 
 (absolute) cubic centimeters. Almost universally the stand- 
 
 1 The term " milliliter " has been applied to this unit to distinguish it from 
 the cube whose edge is I centimeter. 
 
 39 
 
4O ACCURACY OF SACCHAR1METER MEASUREMENTS 
 
 ard of volume used in saccharimeter graduation is the 
 cubic centimeter as modified by Mohr, which in this case 
 can be defined as the volume occupied by i gram of ivater 
 weighed in air zvith brass TV eights at a temperature of 
 17.5 C. As the loo-cubic-centimeter Mohr flask holds 
 100.234 true cubic centimeters, saccharimeters graduated 
 by the different standards vary in actual rotation magni- 
 tudes of the scale divisions by .234 per cent 
 
 This, if not understood, will make confusion when sac- 
 charimeters of the two different graduations are compared 
 with reference to the actual magnitude of the divisions by 
 standard quartz plates, or, if the appropriate measuring 
 flasks are not used, in " polarizing " samples. 
 
 Evidently, flasks should be correctly graduated within 
 .05 cubic centimeter. 
 
 Errors of Instrument. Eccentricity. In rotatory polari- 
 scopes, as in all instruments giving angular measurements, 
 errors are due to the axis of the rotating part of the appa- 
 ratus not being exactly coincident with the centre of the 
 circle on which the scale is graduated. 
 
 This error can be eliminated in instruments having 
 scales extending over the whole circle of rotation in the 
 usual way, by measuring the angle of rotation in opposite 
 quadrants, that is, taking the mean of a and a + 180, for 
 it will be remembered that the end-point phenomena 
 repeat themselves at points 180 distant. 
 
 The "eccentricity" of a polariscope of good make is 
 rarely more than the limit of error of the readings, but 
 occasionally the scale disks of polariscopes become bent 
 by some accident so that errors of more than 4' may be 
 due to this cause. 
 
ACCURACY OF SACCHARIMETER MEASUREMENTS 41 
 
 Errors of Quartz-wedge Saccharimeters. The correct- 
 ness of the saccharimetric scale can be established at a 
 few points by comparisons with standard quartz plates of 
 known rotation. 1 A much more thorough method of cali- 
 bration, which permits all points of the scale to be stand- 
 ardized, is by use of the " control tube." The control tube 
 is telescoping and is adjustable to variations of length 
 through a range of about 100 millimeters, its exact length 
 at any position of adjustment being measured by a scale 
 reading to .1 millimeter. As the readings of the saccha- 
 rimeter are directly proportional to the tube-length, it is 
 possible by means of a few sugar solutions of appropriate 
 strength to verify any reading. 
 
 Since the reading (R) gives the per cent (P) of sugar 
 when /= 2, 2/= 100, and w' is the normal weight (N), the 
 
 equation for the per cent of sugar when any length of tube 
 
 /^ 
 is used is P=R -, and the reading for any length of tube 
 
 will be expressed byR = P If the normal weight of 
 
 . 
 
 chemically pure sugar is used, R = Knowledge of 
 
 the concentration of the sugar solution used is not, how- 
 ever, necessary, if the solution is concentrated enough so 
 that a length (L) can be found which will by experiment 
 for the solution used give a reading of 100 on the saccha- 
 rimetric scale, the correctness of this point having been 
 previously verified by a standard quartz plate, since, obvi- 
 
 1 The values stamped on the plate mountings are not always reliable. 
 Quartz plates can be exactly standardized by sending them to the United 
 States Bureau of Standards, Washington, D.C., which does this work for a 
 small fee. 
 
42 ACCURACY OF SACCHARIMETER MEASUREMENTS 
 ously, any reading (R) will be given when the tube is of 
 
 r> r 
 
 a length , or the reading at any tube-length (/) will be 
 
 i oo . 
 
 expressed by the following equation, R = Thus, the 
 
 j^/ 
 
 actual reading at any position of the wedge can be com- 
 pared with that calculated by the formula. 
 
 Zero Error. In common with most measurements, 
 polariscope readings must be corrected for " zero error," 
 which is the difference in scale divisions between the scale 
 reading at the observed end point and the zero of the 
 scale, when observations are taken with no optically active 
 substance in the instrument. 
 
 Personal Errors of Observer. In all exact measure- 
 ments, the influence of the personal errors of the observer 
 are diminished as much as possible by averaging the results 
 of several readings. In comparing the work of two ob- 
 servers, however, it must not be forgotten that consider- 
 able differences may be shown if the readings of each are 
 uncorrected by the zero error obtained by the observer 
 himself. The results, while differing appreciably in the 
 actual readings, should, on applying the zero corrections, be 
 found to be concordant. Each observer unconsciously 
 uses a slightly different end point, which does not affect 
 the accuracy of his observations, provided the same end 
 point is recognized at zero and at the position of rotation 
 measured. 
 
 Distortion of Cover Glasses of Polariscope Tubes. If the 
 caps of polariscope tubes are screwed on too tightly, so as 
 to produce a strain in the glass, the unequal distribution of 
 density may cause a rotating affect on the light rays and 
 so make error. With the earlier forms of tubes, this was 
 
ACCURACY OF SACCHARIMETER MEASUREMENTS 43 
 
 not unusual ; but with the modern types, with fine-threaded 
 screws and soft rubber washers back of the glasses, error 
 from this cause is rare. 
 
 Laurent has devised tube caps with bayonet catch and a 
 light spring which makes it impossible to exert undue 
 pressure. Landolt accomplished the same object by caps 
 which are held on by the friction of ground joints. The 
 Laurent type is hard to keep clean and free from corro- 
 sion, while the Landolt tubes are more liable to leakage 
 than the screw cap, which is the most practical form and 
 almost universally used. 
 
 Variations from Standard Temperature. Saccharime- 
 ters are graduated to read correctly at 17.5 C., it being 
 assumed that the solution is made up at the standard 
 temperature. Almost always the temperature of modern 
 laboratories is higher than this. The effect of this higher 
 temperature on the reading is a complicated one. The slight 
 increase in the reading, rarely amounting to more than a 
 few hundredths of a division, due to the linear expansion of 
 the tube, is partially compensated for by the slight increase 
 in volume of the flask caused by the expansion of the glass. 
 
 The greatest influence caused by temperature change is 
 on the specific rotation of the sugar, which decreases with 
 temperature increase. Andrews has found that when a 
 sugar solution is made up to the normal concentration and 
 polarized at a temperature greater than 17.5 C., the read- 
 ings are too low, in the case of a rotatory saccharimeter, 
 by .00018 of their value for every degree of temperature 
 above the standard. 
 
 This assumes that all apparatus, flask, tube, and sac- 
 charimeter, as well as the water used in making up the 
 
44 ACCURACY OF SACCHARIMETER MEASUREMENTS 
 
 solution, are at the same temperature. In the case of the 
 quartz-wedge saccharimeter, a greater error is introduced, 
 owing to the increase in specific rotation of the quartz 
 wedges by temperature increase. 1 Andrews found that 
 the correction for quartz-wedge saccharimeters was .00030 
 per degree above standard temperature. Wiley 2 has con- 
 firmed this latter correction more recently by an investiga- 
 tion covering temperatures from o to 40 C. Investigators 
 of the United States Coast and Geodetic Survey had 
 arrived at practically the same correction value as early as 
 1890. The coefficient calculated from Schonrock's recent 
 values is somewhat higher. 
 
 It must be understood clearly that correction for tem- 
 perature can only be made when the temperature condi- 
 tions are constant. Especially in the case of quartz-wedge 
 saccharimeters, such corrections may be quite fallacious if 
 there is considerable temperature variation during the day, 
 as the quartz wedges, which are the parts. of the instru- 
 ment most affected, assume the outside temperature very 
 slowly, owing to their thickness and poor conductivity. 3 
 Constant temperature conditions are vital for accurate sac- 
 charimetric work. 
 
 Although these values for temperature correction seem 
 well established by careful investigation, they are disputed by 
 some, and have not yet been applied in commercial testing. 
 
 1 Technology Quarterly, 1889, p. 367. Id., p. 373. 
 
 2 /. Am. Chem. Soc., 1899, p. 568. 
 
 3 Variations of considerable magnitude occur in polariscope readings 
 caused by temperature changes apparently due to the displacement of the 
 optical parts by the expansion or contraction of the metal in the mounting of 
 the instrument. These manifest themselves in the zero error, which should 
 be frequently taken during temperature changes. 
 
ACCURACY OF SACCHARIMETER MEASUREMENTS 45 
 
 Quartz plates, when properly mounted, always give con- 
 stant readings on the quartz-wedge saccharimeter at all 
 ordinary temperatures, provided that the quartz-wedge com- 
 pensator system and the plate are at the same temperature. 
 Obviously, the temperature changes affecting the rotation 
 will be alike in the plate and compensator. On this 
 account, quartz plates are the most convenient for standard- 
 izing this type of saccharimeter, as control-tube standard- 
 ization requires most careful temperature correction if the 
 sugar solutions are not made up and polarized at the 
 standard temperature. 1 
 
 Most sugar chemists have adopted the recommendations 
 of the International Commission for Uniform Methods in 
 Sugar Analysis, and agreed to make all polarizations at 20. 
 
 In the case of instruments measuring the angle of 
 rotation of the quartz plate directly (rotatory polariscopes), 
 the coefficient of increase of rotation for every centigrade 
 degree of temperature above standard is .000143. 
 
 1 Commercial saccharimeters used for valuing raw sugars and molasses are 
 usually standardized by means of carefully corrected quartz plates of values 
 approximating within a few per cent the polarization of the sugar to be tested. 
 The reading of the plate given by the instrument is carefully corrected to the 
 true value of the plate, and this correction applied to the polarization of the 
 sample, the zero error being ignored. By this method of correction, the dif- 
 ference in actual magnitude of the scale divisions of instruments graduated in 
 true or Mohr cubic centimeters is negligible, provided the readings of the 
 standard quartz and the sample polarized do not differ more than 4 or 5 per 
 cent, for in that interval a variation of less than .3 per cent in, say, 5 divisions 
 would make an error of only .015, which is obviously well within the error of 
 observation. Even a sugar polarization varying 20 divisions from the standard 
 plate value, if the saccharimeter were standardized to that value independently 
 of its zero error, would be correct within .06 ; if, for instance, a Mohr cubic 
 centimeter flask were used instead of a true cubic centimeter flask in making 
 ' up the solution. 
 
46 ACCURACY OF SACCHARIMETER MEASUREMENTS 
 
 The scale of graduation for quartz-wedge saccharimeters 
 (almost universal throughout the commercial sugar world) 
 being that for 26.048 grams of sugar dissolved in 100 
 MoJir cubic centimeters (the original Ventzke scale), Herz- 
 feld has calculated the normal weight for this original 
 and standard scale, when the sugar is made up to 100 trite 
 cubic centimeters (" milliliters ") and polarized at the more 
 convenient temperature of 20, to be 26.01 grams. 
 
 This calculation can be expressed by the following 
 equation : 
 
 N = - 26.o 4 8[i+(20- I7.5).oooi 4 3] 
 ^.234 j 
 
 (i (20 I7.5).ooo2i7/ 
 
 The part in the brackets represents the increase in 
 rotatory power of the quartz in the compensator of the 
 saccharimeter due to the difference in temperature between 
 17.5 and 20, necessitating a proportional increase in the 
 normal weight. The last member in the parenthesis shows 
 the decrease in rotatory power of the sugar caused by the 
 higher temperature. 1 
 
 The International Commission has decided to use the 
 even value 26.00. The difference of .01 gram, amounting 
 to .04 per cent, may be of no consequence in ordinary com- 
 mercial work, but is hardly in accord with the recom- 
 mendation of the Commission to weigh all samples to .001 
 gram, or to .004 per cent. 
 
 The official saccharimetric standard adopted by the 
 United States Customs 2 is 26.048 grams, weighed in 
 
 1 Zeitschr. Analyt. Chem. 38, A. V. u. E. 22. 
 
 2 United States Treasury Document No. 2113, Division of Customs, p. 16. 
 
ACCURACY OF SACCHARIMETER MEASUREMENTS 47 
 
 vacuo, and dissolved in 100 true cubic centimeters, all 
 solutions being made and polarized at 17.5. 
 
 Apparently all Schmidt and Hansch saccharimeters 
 sent to the United States subsequently to about 1892, and 
 having a serial number above 3200, are graduated for 
 26.048 grams of sugar in 100 true cubic centimeters to 
 conform to this standard. (See footnote No. 2.) The 
 Peters saccharimeters examined by the author have been 
 standardized on the original Ventzke scale. 
 
 Special errors peculiar to commercial saccharimetry will 
 be discussed under the descriptions of commercial sugar 
 polarizations. 
 
GENERAL NOTES ON APPARATUS AND 
 LABORATORY MANIPULATION 
 
 Installation. The laboratory for polariscopic testing 
 should be kept at as nearly a constant temperature as 
 possible, preferably 20, and therefore be well ventilated, 
 and of sufficient size not to be affected by the heat of 
 lamps. Polariscope apparatus should be so installed that 
 the observer is screened from outside light. 
 
 This is done sometimes by placing the polariscope in a 
 separate darkened room, the light passing into the instru- 
 ment through a hole in a partition from a lamp outside, 
 appropriate means of illumination of scales being by re- 
 flectors or small electric or gas lights. The more con- 
 venient method is to place the apparatus in a large,' well- 
 ventilated hood, so located in a shaded part of the room 
 that the direct light cannot enter, the necessary illumina- 
 tion being arranged as described. 
 
 The polariscope should be screened from the direct heat 
 of the lamps by glass plates or, better, absorption cells 
 filled with water. 
 
 Care of Instruments. Like many instruments of preci- 
 sion, polariscope apparatus is extremely sensitive to de- 
 rangement from careless handling. Polariscopes should be 
 disturbed as little as possible beyond the usual manipula- 
 tion of testing. Nicol prisms, from the nature of their 
 material, are peculiarly liable to injury. Calc-spar, being 
 
APPARATUS AND LABORATORY MANIPULATION NOTES 49 
 
 much softer than glass, is easily scratched by careless 
 handling or cleaning. Its peculiar crystallization makes it 
 liable to split from rapid changes of temperature, as in 
 overheating by placing the instrument too close to the 
 lamp. Calc-spar is easily corroded by acids caused by 
 fermentation of sugar solutions carelessly spilled in the 
 instrument. With proper care, polarizing apparatus will 
 last a lifetime. As the accuracy of the sugar chemist's work 
 is dependent on the precision of the instrument, daily prac- 
 tice in such care as will insure this precision is obviously 
 a necessary part of the knowledge and duties required of 
 every worker in a sugar laboratory. 
 
 Handle the instrument with clean hands. See that the 
 flame of the lamp is about 200 millimeters (the length of 
 an ordinary polariscope tube) from the end of the instru- 
 ment. This avoids overheating, which not only endangers 
 the prisms, but throws the instrument out of adjustment. 
 With most types, it also insures an evenly illuminated field 
 of maximum brightness, as the foci of the condensing 
 lenses are adjusted for this distance. Only when absolutely 
 necessary, clean lenses, quartz wedges, and cover glasses 
 with perfectly clean filter paper or linen cloth, never with 
 silk or chamois, as the rough surfaces of these fabrics are 
 liable to hold grit. Always rub very lightly. In cases 
 where the edges cannot be reached, remove dirt very 
 carefully with a clean, pointed stick of soft wood, as a 
 toothpick. 
 
 Clean Nicol prisms with special care, and only when 
 absolutely necessary. In the best instruments, Nicol prisms 
 are protected by cover glasses where they would other- 
 wise be exposed. 
 
50 APPARATUS AND LABORATORY MANIPULATION NOTES 
 
 Polariscope Lamps. Many forms of sodium-light lamps 
 have been devised. Most of them use ordinary table salt, 
 which is best adapted for the purpose, the other common salts 
 of sodium not volatilizing so readily, and consequently giv- 
 ing less intense light. Sodium carbonate works reasonably 
 well, but causticizes to a considerable extent, forming a 
 corrosive liquid which drops down and fouls the apparatus. 
 Sodium bromide is said to produce a more intense light 
 than the chloride, but gives off bromine vapors which are 
 liable to injure the polariscope. Landolt uses cylinders 
 of salt which are fused on small forms made of nickel wire 
 netting. Wiley has devised a clockwork lamp by which 
 the salt is fed into a Bunsen flame from opposite sides by 
 means of two slowly revolving wheels of platinum gauze 
 which dip into dishes holding a salt solution. The author 
 has preferred the ordinary type of lamp, which consists of a 
 Bunsen burner so adjusted as to burn with as strong an 
 air blast as possible, this being a requisite for any lamp 
 giving intense light. The salt is exposed to the flame in a 
 platinum or nickel gauze spoon, which is heated in the 
 mantle just outside the luminous cone, the hottest part 
 of the flame. The intensely bright yellow sodium vapor 
 is then carried by the blast well above the blue cone of the 
 flame, the light of which latter should be cut out of the 
 polariscope field by a diaphragm attached to the lamp. A 
 mixture of table salt with sodium phosphate, as recom- 
 mended by Dupont, fuses upon the gauze and does not de- 
 crepitate as salt does alone. A mixture of these powdered 
 salts made into a paste with a little glycerine has been 
 found very convenient for applying to the gauze with a 
 small platinum spatula, 
 
APPARATUS AND LABORATORY MANIPULATION NOTES 51 
 
 Quite recently the author has adopted a simple type 
 of sodium lamp which has proved by far the most con- 
 venient and efficient. A shallow boat, made by folding up 
 a rectangular piece of platinum foil and welding together 
 the ends by hammering at a red heat, is used to hold the 
 salt. The boat is of such shape as to spread the flame of 
 a Tirrill burner, which impinges against the polished plati- 
 num, after the manner of a batwing flame. The salt which 
 is liquefied creeps up the sides of the boat, and is vaporized 
 in the flame sheet, giving a very brilliant and steady light 
 which lasts for fifteen minutes or more without renewing 
 the salt. 
 
 The flame shoots off obliquely, thus exposing more light 
 surface in the axis of vision. From time to time lumps of 
 salt (which have been previously fused) are added till the 
 boat is again filled with liquid. 
 
 The diagrams explain the apparatus, the exact adjust- 
 ment of the position of the 
 platinum boat being easily 
 determined by experiment. 
 
 A more elaborate but 
 somewhat more efficient 
 boat for holding the salt is 
 shown in Figure 1 2. A piece 
 of platinum foil is folded 
 double in such a way as to 
 make a double-bottomed 
 boat, the edges of the folded 
 sheet making a narrow slit 
 along one edge of the boat. The inner bottom is perfo- 
 rated. In this form the liquefied salt rises by its capil- 
 
 
 
 B 
 
 
 B 
 
 
 
 \ 
 
 
 ^ 
 
 I 
 
 Side Section Front 
 
 FIG. II. 
 
 . Boat. D. Yellow flame. 
 . Burner-tube. F. Diaphragm-opening. 
 Blue flame cone. 
 
52 APPARATUS AND LABORATORY MANIPULATION NOTES 
 
 larity to the mouth of the slit and is taken by the strong 
 blast of the lamp up into the flame in a brilliant sheet. 
 Such an arrangement has given a constant light for an 
 hour without replenishing. 
 
 The platinum boats must not be too large, or the mass 
 of metal chills the flame and reduces the intensity of the 
 plan of goat light appreciably. It may be needless 
 
 s^^^^^^^- to add also that the burner must be 
 working with as strong an air blast as 
 N^y^-'' possible. 
 
 Most polariscopes are equipped with 
 a plate of potassium bichromate crystal 
 to filter out extraneous rays. Landolt 
 Boated Burner uses an absorption cell filled with a 
 weak solution of this salt, and a second 
 cell containing a solution of uranous sulphate. 
 
 For the quartz-wedge saccharimeter, any strong lamp- 
 light serves. The Welsbach light is particularly good. 
 Where gas cannot be had, Welsbach burners can be 
 obtained which use vaporized kerosene on the type of the 
 " Washington " light. 1 Acetylene and incandescent electric 
 lights are often used. Schmidt and Hansch have per- 
 fected an electric light which can be attached to their 
 saccharimeters. This is of small size and, while giving 
 light of great intensity, produces very little heat. 
 
 Balance. For ordinary polariscope work, a quick-work- 
 ing balance with a capacity of 200 grams and sensitive to 
 .005 gram is preferable to the more precise analytical type. 
 It should be inclosed in a glass case. Such balances, 
 known as " sugar balances," are made by all the leading 
 
 1 Used by the writer in Porto Rico. 
 
APPARATUS AND LABORATORY MANIPULATION NOTES 53 
 
 manufacturers. They are also best adapted for calibrat- 
 ing most volumetric apparatus. A " trip scale " with a 
 capacity of 2 kilos and sensitive to .1 gram is indispensa- 
 ble for many of the 
 laboratory opera- 
 tions incident to 
 preparation of so- 
 lutions and cali- 
 brating the larger 
 volumetric appa- 
 ratus; while, of 
 course, many of 
 the more delicate 
 weighings of exact 
 
 FIG. 13. SUGAR-BALANCE. 
 
 density determina- 
 tions and other 
 gravimetric measurements require a delicate analytical 
 balance. 
 
 Sugars and other non-corrosive substances are usually 
 weighed out in nickel or German silver dishes provided 
 
 with a lip for pouring. 
 These dishes are numbered 
 and provided with a cor- 
 respondingly numbered 
 
 tare weight. The sub- 
 FIG. 14. -WEIGHING-DISH AND TARE stance j s dther dissolved 
 WEIGHT. 
 
 directly in the dish by rub- 
 bing the crystals under water, using a metallic pestle, 
 or washed into the measuring flask, the former being the 
 usual method. 
 
 In saccharimetric work, either the normal or half-normal 
 
54 APPARATUS AND LABORATORY MANIPULATION NOTES 
 
 weight is taken, brass weights of this value being furnished 
 with the saccharimeter. The half-normal weight is only 
 used when the sample makes a dark solution not readily 
 clarified, and consequently difficult to read in the polari- 
 scope, such as a low-grade molasses, for instance. [For 
 Manipulation of Polariscope Tubes, see p. 91.] 
 
 Flasks. The loo-cubic-centimeter flask is the one 
 most conveniently used. Practically all commercial sac- 
 charimeters are graduated for solutions made up to 100 
 Mohr cubic centimeters, the unit of which has already 
 been defined as the volume occupied by i gram of water 
 at a temperature of 17.5, weighed in air with brass 
 weights. Recently there has been a strong movement 
 on foot among the chemists of all nations to use the true 
 centimeter as the basis of measurement. [See p. 46.] 
 
 Special Laboratory Apparatus. Short-stemmed funnels 
 of a capacity of 75 to 100 cubic centimeters have been 
 found most convenient for filtering solutions for polarizing. 
 These funnels are placed directly on heavy glass cylinders 
 for receiving the filtrate, thus obviating a separate filter 
 stand. The cylinders have a lip for pouring, and, most 
 conveniently, a capacity of 100 cubic centimeters. Watch 
 glasses are used to cover the funnels to prevent evapora- 
 tion during filtering. 
 
 Besides the ordinary loo-cubic-centimeter flasks, those 
 with a double mark on the neck, one at 100, the other at 
 no cubic centimeters, as well as similar ones marked at 
 50 and 55 cubic centimeters, are used in special operations, 
 to be described later. 
 
 Clarifying reagents, such as basic lead acetate, are pref- 
 erably stored in large bottles arranged with delivery tubes 
 
APPARATUS AND LABORATORY MANIPULATION NOTES 55 
 
 for convenience in using. The delivery tube should be 
 connected with a coarse burette, or, what is more cleanly, 
 a graduate used so that the volume of the reagent added 
 is known with fair accuracy. This is important in some 
 cases where corrections are to be made for errors caused 
 by clarifying. 
 
 A similar tubulated bottle of large capacity should be 
 provided for the water used in making up solutions which 
 thus can be maintained at laboratory temperature. A 
 convenient arrangement is to equip the bottle with two 
 delivery tubes, one for quick delivery, the other a fine jet 
 for filling flasks to mark. 
 
 Other apparatus, such as a muffle for ash determinations, 
 drying ovens, etc., need not be considered here, as it differs 
 in no wise from that used in general food chemistry. 
 
 Immediately after use, all glass apparatus, as well as 
 polariscope tubes, should be washed in running water and 
 placed on racks to dry. This insures a sufficient supply 
 of clean and dry apparatus at all times. 
 
 Brix Spindles. Brix spindles 1 are most conveniently 
 made in the following sizes: 0-5, 5-10, 10-20, 20-30, or 
 with a range of not over 10 for the higher concentrations. 
 They should be equipped with thermometers, and not be 
 too large for convenient use, not over 12 or 14 inches long. 
 The graduations should be of sufficient size to permit of 
 easily reading to .1. If the expansion corrections for 
 17.5 are marked on the thermometer scales, they should 
 be figured for the middle Brix reading ; for instance, for 
 a 10-20 hydrometer the expansion corrections should be 
 for 15. 
 
 1 Described on p. 117. 
 
56 APPARATUS AND LABORATORY MANIPULATION NOTES 
 
 A draining rack with holes for holding the spindles 
 should be provided, or pockets made of copper gauze, 
 which are very convenient. 
 
 Calibration of Flasks. Weigh the thoroughly cleansed 
 and dried flask to .005 gram. Weigh again when filled to 
 the mark with freshly distilled water of known tempera- 
 ture. The volume of the flask, in Mohr cubic centimeters, 
 can be computed from the following formula : 
 
 v=P ^ l ~' 000025(^-17.5)]; 
 
 where v expresses the desired volume at 17.5; P, the 
 weight of water in grams which fills the flask to the gradu- 
 ation mark at the temperature /; d y the density of water 
 at 17.5 C. ; and d' the density of the water at temperature 
 of weighing. These density values are obtained from 
 tables. That part of the equation which is inclosed in 
 brackets expresses the correction on the volume caused by 
 the expansion of the glass of the flask, and is small enough 
 to be omitted for ordinary calibrations made at room tem- 
 peratures. 
 
 Flasks for commercial saccharimetry are usually gradu- 
 ated by reading the lower edge of the meniscus of the 
 water surface tangent to the upper edge of the graduation 
 mark on the neck of the flask, when the whole of the 
 meniscus is shaded. This is done by holding the flask up 
 to the light with the mark on a level with the eye, or look- 
 ing at the mark against a background, made by a piece of 
 white paper, held in strong light a few inches back of the 
 flask. Care must be taken to have the flask neck perpen- 
 dicular if the flask is held in the hand while reading the 
 
APPARATUS AND LABORATORY MANIPULATION NOTES 57 
 
 mark, as well, of course, to be sure that the neck above the 
 water surface is perfectly dry. If there are adhering drops, 
 they should be removed completely with a wisp of filter 
 paper. 
 
 True cubic centimeter flasks, as has been stated already, 
 are graduated on a unit which is the volume occupied by 
 i gram of water weighed in vacuo at its maximum density 
 (4). The weight of the air displaced in the space taken 
 by the water is only partially balanced by the air displace- 
 ment of the weights in the other pan of the balance, as the 
 volume of the latter is less than one eighth as large, owing 
 to their greater density. In consequence the actual mass 
 of the water weighed is expressed by a value somewhat 
 more than . I per cent greater than its apparent weight in 
 air. It can be shown that the true mass of any given 
 volume of water can be found from its weight in air with 
 ordinary weights by the formula, 
 
 where W is the weight expressing the true mass ; P t the 
 weight actually found by weighing in air by the ordinary 
 method; cr, the density of air, taken as .0012; S, the den- 
 sity of water, taken as i.oo; and A, the density of the 
 balance weights, taken as 8.4. With these values, which 
 are approximate enough for flask calibration, the value of 
 
 i ) is .00106. 
 
 S A/ 
 
 Moreover, as the water weighed at any temperature 
 other than 4 is less dense, its volume is greater than at 
 the standard temperature. 
 
58 APPARATUS AND LABORATORY MANIPULATION NOTES 
 
 Hence, the complete formula expressing the volume of 
 a flask in true cubic centimeters at 20 when the water 
 it contains is weighed in the ordinary manner at the 
 temperature t y is 
 
 v = (P + .00106 P) [i - .000025(7 - 20 )] ; 
 
 where d is the density of water at 4, and d* the density at 
 the temperature it had when weighed. 
 
 The 100 Mohr cubic centimeter flask used in saccha- 
 rimetry has a volume of 100.234 true cubic centimeters. 
 The 100 true cubic centimeter flask contains 99.766 Mohr 
 cubic centimeters. 
 
 Flasks should be numbered (conveniently, by marking on 
 the neck with a diamond) and their calibrations recorded. 
 
 Observations. Before taking readings see that the field 
 and the scale are properly illuminated. The field should 
 be as evenly and brightly lighted as possible at the end 
 point, and its image sharply focused. The image is 
 focused by moving the eyepiece in or out in its telescop- 
 ing sleeve. 
 
 A perfectly defined field is vital for precise reading. 
 Before adjusting focus and illumination in shadow instru- 
 ments, first turn the analyzer (or in quartz-wedge compensa- 
 tion instruments, the wedge pinion) so that the scale reads 
 some divisions from zero to get the full volume of light. 
 After placing the tube of solution in the instrument, the 
 focus must be readjusted. 
 
 Every effort should be made to have solutions for polar- 
 ization absolutely clear. It is advisable to filter solutions, 
 even if made from pure substances, as even a slight opal- 
 
APPARATUS AND LABORATORY MANIPULATION NOTES 59 
 
 escence due to minute traces of foreign matter affects the 
 definition of the image and consequently seriously affects 
 the precision of the readings. 
 
 Practice rapid readings, averaging the results of several 
 rather than fatigue the eye by long observations. Rapidly 
 taken readings, if taken with care, are more accurate. 
 
 The room temperature, which should be the temperature 
 of the apparatus and solutions, should be recorded at the 
 time of observation. 
 
 End Point. (jShadow instruments.") After setting at 
 zero (by the scale), manipulate the instrument so as to 
 move the shadow slightly from one side of the field to the 
 other several times, confining the attention to the central 
 vertical line. Take the point of transition of the shadow 
 across this line as the end point is approached from opposite 
 sides of the field in different observations. This is theoreti- 
 cally the same point as that found by setting the instrument 
 for equal illumination of both halves of the field, but is 
 easier for most observers. This method also enables ac- 
 curate readings to be taken in certain cases where dust, 
 faulty illumination, imperfect adjustment of prisms, or dis- 
 persion variations (in wedge saccharimeters) make it im- 
 possible to get both halves of the field to look exactly alike. 
 Of course the field will be equally illumined, in the case 
 of a shadow instrument, when there is a rotatory effect 
 approaching 90 from the true end point, but no shadow 
 effect will appear, as already noted. The general approach 
 toward the true end point will be shown by the rapid 
 darkening of the field as a whole. 
 
 If separate scale lights are used, they should be kept 
 turned off except when reading the scale, to prevent heat- 
 
60 APPARATUS AND LABORATORY MANIPULATION NOTES 
 
 ing the instrument. Any outside glare also quickly im- 
 pairs the sensitiveness of vision in precise work. 
 
 In beginning work with an unfamiliar instrument, set 
 the scale at zero, and study the changes of field about this 
 point. This is better than hunting blindly for what you 
 may not recognize, with possible injury to your eyesight 
 if not to the instrument. It is especially important to 
 make this zero setting when some unusual end point is 
 observed, as in the Wild polariscope. 1 
 
 Scale Readings. Always correct for "zero error " (the 
 difference between the end point observed as read on the 
 scale and the zero of the scale), noting whether this is plus 
 or minus. In case zero error is not large, it is better to 
 allow for it in calculations than to attempt to bring the 
 scale into perfect adjustment with the end point. Frequent 
 determinations of zero error should be made, especially if 
 the temperature is changing. 
 
 Take the average of at least six readings for all exact 
 work, rejecting the first reading if it shows much discrep- 
 ancy from the others, or any other of the series which is 
 clearly wrong, owing to some circumstance peculiar to that 
 individual observation, and not affecting the others of the 
 series, as, for instance, eye fatigue, which passes away after 
 a moment's rest. 
 
 All saccharimeter scales are expressed in percentages 
 and tenths. Polariscopes measuring rotations directly, ex- 
 cept a few of most recent type, give readings in degrees 
 and minutes. Saccharimeter scales are graduated into 
 divisions expressing per cents, rotatory scales into halves 
 
 1 Special notes on the use of instruments of different types are given in 
 next chapter. 
 
APPARATUS AND LABORATORY MANIPULATION NOTES 6 1 
 
 or thirds of a degree. In both cases, values smaller than 
 these graduations, expressed as fractions of the smallest 
 scale division into which the scale is actually graduated, 
 are determined by " verniers." A vernier, so-called from 
 its inventor, a French mathematician, is a device for read- 
 ing fractions of the smallest division of a scale. In the 
 form used in polariscopes, it is a sliding scale parallel to 
 and extending along the main scale, graduated in both 
 directions from the zero line which is the index mark 
 whose position the main scale measures. 
 
 Each half of the vernier scale extending from the zero 
 mark has a length which is, measured in smallest divisions 
 of the main scale, one less than the denominator of the 
 fraction which the vernier is designed to determine, while 
 this length of the vernier scale is itself divided into just 
 the number of parts which express this denominator. 
 
 For instance, a vernier designed to divide a scale divi- 
 sion into ten equal parts is itself nine scale divisions long, 
 but is divided into ten equal parts. Hence in this example 
 each vernier division is -$ of the main scale division. If 
 the zero line of the vernier (which, it must be remembered, 
 is always the index or point of reference of the main scale) 
 does not coincide with a main scale division, but is distant 
 -Q, evidently \hzfirst line of the vernier scale will coincide 
 with the next main scale division line. If the zero mark 
 is distant tzvo tenths of the main scale division interval 
 from a line, the second line of the vernier scale will coin- 
 cide with a main scale line, and so on. 
 
 The following rules can be given for vernier readings : 
 
 (i) First determine the fraction of the scale divisions 
 which the vernier expresses, by actually counting the 
 
62 APPARATUS AND LABORATORY MANIPULATION NOTES 
 
 number of divisions of the vernier scale, in either direction 
 from zero. 
 
 (2) Starting from the zero of the vernier and reading in 
 the direction of the main scale readings, the number of 
 the line of the vernier scale (counting from zero) which 
 coincides with a line of the main scale gives the number 
 of parts of the scale division which the index (zero line 
 of vernier) marks. 
 
 Hence, in the case of a vernier reading tenths, if the 
 zero line of the vernier lies beyond the twenty-sixtJi main 
 scale division, and the seventh line of the vernier coincides 
 with a line of the main scale, the reading will' be 26.7. 
 
 I \ 
 
 1 
 
 1 f 
 
 I f 
 
 f I r i i i 
 
 i i 
 
 
 
 
 III I I II 1 
 
 
 IJ J 
 
 "I 
 
 ! U 
 
 TJ 
 
 i 
 
 TTi 
 
 
 10 
 
 
 
 1G 
 
 
 FIG. 15. VERNIER READING 26.7. 
 
 When the zero line of the vernier lies on the minus side 
 of the scale, the lines of the corresponding side of the 
 vernier are read. On rotatory scales of polariscopes in 
 chemical laboratories verniers usually read to even min- 
 utes only, half degree divisions being divided into fifteen 
 parts, thirds of a degree divisions into ten parts. In read- 
 ing rotatory scales the number of divisions marked by the 
 zero of the vernier is first read and then expressed in 
 degrees and minutes. Not until this is done should the 
 vernier be read and its reading added. Study system of 
 division till you thoroughly understand it before taking 
 readings. 
 
 In rotatory instruments, the direction of rotation is abso- 
 
APPARATUS AND LABORATORY MANIPULATION NOTES 63 
 
 lutely determined for rotations less than 180, but in the 
 case of a quartz-wedge saccharimeter, where the actual 
 direction of the scale readings has no direct reference to 
 that of the rotation of the plane of polarization, the plus 
 direction of the scale is sometimes to the right and some- 
 times to the left. In most commercial saccharimeters, the 
 plus direction is to the right ; in some of the old instruments 
 and in double-wedge compensation saccharimeters, it is to 
 the left. An inspection of the scale will always make 
 clear which is the plus direction of the readings, for, as 
 the scale is designed for measuring sugar, a right (plus) 
 rotating substance, the long end of the scale will be the 
 plus. 
 
 Form the habit of checking all observation by taking a 
 final reading of the large divisions, independent of the 
 vernier reading. This practice will often detect errors, 
 as an observer naturally tends to concentrate his attention 
 on the more difficult vernier reading, and, becoming care- 
 less of the reading of the main scale, often repeats an 
 error once made throughout the whole series of readings. 
 
 Calculated results and averages should be carried to one 
 decimal beyond that expressing the limit of scale reading, 
 following the usual practice of physical measurements. 
 
 Calculation of Errors of Analysis. It would seen super- 
 fluous to call attention to the importance of calculating the 
 influence of the errors of measurements on the accuracy 
 of polarimetric determinations, were it not that there is 
 abundant evidence that a "profound ignorance" of the 
 elementary principles of the precision of measurements is 
 prevalent among chemists. Much valuable time can be 
 saved and procedure simplified in many cases, if preliminary 
 
64 APPARATUS AND LABORATORY MANIPULATION NOTES 
 
 calculations of precision are made. Further, with positive 
 knowledge of the limit of precision of all measurements, 
 any uncertainty is reduced to a chance accident or some 
 error inherent in the method. 
 
 It is obviously bad practice, for instance, to calibrate a 
 100 cubic centimeter flask on an analytical balance when 
 it is practically impossible to read the meniscus to a differ- 
 ence corresponding to less than a centigram (and this dif- 
 ference, moreover, representing an error of .01 per cent), 
 leaving out of consideration the fact that with the case 
 filled with moisture, the balance is for some time quite 
 unfit for its necessary uses, as for weighing freshly ignited 
 substances, like ash. It is also easily demonstrated that 
 it is absurd to weigh the normal weight of sugar to milli- 
 grams, as recommended by eminent authority. 
 
 The discussion of errors of saccharimetric measure- 
 ments given in the previous chapter will illustrate the 
 investigation of errors of measurement of a polarimetric 
 method. 
 
 Notes. Another vital point in chemical practice which 
 is much neglected, and one not so easy to acquire proficiency 
 in as it would seem, is that of making complete and accu- 
 rate record of all the experimental data of an analysis. 
 Much valuable work is lost yearly through neglect of proper 
 recording, necessitating a large expenditure of time and 
 labor in repetition. On the other hand, the accurately 
 detailed results of the chemists of fifty years ago are often 
 as valuable as the work of to-day, owing to the complete 
 notes of data which make it possible to recalculate the 
 results by the constants which accord with modern theory 
 and practice. 
 
APPARATUS AND LABORATORY MANIPULATION NOTES 65 
 
 In polarimetry, owing to much use of constant values of 
 measurement and the mechanical nature of many of the 
 methods, there is more temptation to take data for granted 
 than in procedure where measurements peculiar to each 
 determination make record absolutely necessary. The 
 laboratory records of polarizations should, nevertheless, 
 show exactly the value of each datum. The tempera- 
 ture at which the solutions are made and polarized, as 
 well as the amount and nature of the clarifying agents 
 used, should be recorded also, as these items may well 
 be of consequence, especially in sugar analysis, in the 
 future. The test of the value of a set of notes might be 
 put as follows, that at any time in the future they prove 
 complete enough to enable an independent worker with a 
 knowledge of the literature of the subject to duplicate the 
 original determination exactly. 
 
 Where large numbers of determinations are made by a 
 uniform method, much time can be saved by the use of 
 printed blanks in which appropriate spaces are allotted 
 for data. Any important omission in the record is evident 
 by a glance. Illustration is given of such a blank used by 
 students for records of data of a series of twelve practice 
 determinations in polarimetry. In complicated calcula- 
 tions, such as in the complete determination of hydrolyzed 
 starch products, such blanks, printed or made by hekto- 
 graph or similar process, are particularly valuable. The 
 computations are greatly simplified by printing the loga- 
 rithmic constants of calculations in appropriate tabular 
 form, while in addition there is the important advantage 
 already mentioned, that data, always recorded in definite 
 places, can be read at a glance. 
 
66 APPARATUS AND LABORATORY MANIPULATION NOTES 
 
 MASSACHUSETTS INSTITUTE OF TECHNOLOGY 
 
 OPTICAL ANALYSIS OF SUGAR 
 
 No.. 
 
 Date Determination,. 
 
 Instrument Light 
 
 Test. /_ 
 
 Brix /. Brix (corrected) Sp. Gr 
 
 w' N- v / 
 
 Test : Zero Error : 
 
 Flask No 
 
 \ Calibration. _ 
 
 Av. Av Correct reading. 
 
 Instrument Light 
 
 Test /_ 
 
 Brix /. Brix (corrected) Sp. Gr. 
 
 w' N, v L 
 
 Test : Zero Error : 
 
 Flask No... 
 Calibration_ 
 
 Av Av - Correct reading- 
 Result of Tests : 
 
 (Signed)... 
 
APPARATUS AND LABORATORY MANIPULATION NOTES 6/ 
 
 This blank is introduced here merely as an illustration 
 of one applied to a special series of determinations many 
 of which require two separate polarizations and some of 
 which, as glucose and quotient of purity determinations, 
 require Brix or density measurements. As suggested, it 
 is advisable to have data of clarification also. A better 
 title would be " Polarimetric Analysis," as investigation of 
 tartaric acid is also included. 
 
NOTES APPLYING TO SPECIAL INSTRUMENTS 
 
 (To be read in conjunction with the General Notes) 
 A. ROTATORY POLARISCOPES 
 
 The Laurent Polariscope. See that the lamp is properly 
 adjusted to give an intense flame. The air valve (V) should 
 be regulated to give a strong blast, making the blue cones 
 of the inner flame as low as possible. The gauze basket (A) 
 holding the salt mixture should be parallel to the flame 
 cones, and be just outside of them, in the hottest part of 
 the flame. If care is taken in this adjustment, the upper 
 part of the flame will be a very brilliant yellow from the 
 incandescent sodium vapor. The salt must be applied 
 every few minutes. The flame should be about 2 decime- 
 ters from the end of the polariscope, the length of an ordi- 
 nary polariscope tube, as the condensing lens (B} is 
 properly focused on the flame at that distance. (See 
 description of improved lamp in previous chapter.) 
 
 Turn the analyzer by pinion G till the scale (observed at 
 N) reads some degrees from zero, so as to get a bright 
 illumination, and focus sharply with the eyepiece (O) on the 
 luminous disk made by the image of the diaphragm open- 
 ing (D) bisected by the quartz plate. 
 
 Turn the analyzer to zero, and raise the lever (U) on the 
 left, behind the scale disk 1 (7), till just enough light passes 
 
 1 In some polariscopes of the Laurent type, especially the German instru- 
 ments, the adjustment lever of the polarizer is directly over the prism, its 
 movement being measured on a graduated scale. 
 
 68 
 
NOTES APPLYING TO SPECIAL INSTRUMENTS 
 
 6 9 
 
 to make a well-defined image in which the shadow changes 
 are easily discernible. This gives maximum sensitiveness. 
 Determine zero error at o and 180, if the graduation of 
 the instrument admits of readings in opposite quadrants. 
 If the " eccentricity " of the scale is shown to be less than i r 
 in readings taken at different rotations, observations in the 
 opposite quadrant can be dispensed with henceforth. In 
 
 FIG. 16. LAURENT POLARISCOPE AND SODIUM LAMP. 
 
 the larger instruments, the angular-degree scale extends 
 entirely around the circle, the saccharimetric scale being 
 in the upper half of the circle, concentric to it. In 
 the smaller instruments, the degree scale is in one half of 
 the circle, the saccharimetric scale in the other. Study the 
 scales carefully till the graduation is thoroughly under- 
 stood. 
 
 Avoid turning the adjustment pinion (F) on the eyepiece 
 tube, as this is intended for adjustment of the analyzer 
 
7O NOTES APPLYING TO SPECIAL INSTRUMENTS 
 
 with the scale, and moves the prism independently of the 
 scale. 
 
 The angle which the plane of polarization of the polar- 
 izer makes with that of the Laurent plate should not be 
 too small, for not only the dimness of the light at the end 
 point prevents distinguishing with precision slight differ- 
 ences of shade, but, inasmuch as the small amount of stray 
 blue rays which pass the bichromate plate are not so com- 
 pletely extinguished, if at all, at the end point, owing to 
 their unequal refrangibility, these may predominate to such 
 an extent when the sodium light is too far reduced by 
 defective working of the lamp or by an excessively small 
 angle between the planes of polarization in the two halves 
 of the field, as to change the " optical centre " of the light 
 and make an error of some minutes in the reading. An 
 angle of 2-4 to the quartz axis (which is one half of 
 the angle of tilting of the planes of polarization) is small 
 enough for most accurate measurements in the work of the 
 chemical laboratory. This angle can be measured roughly, 
 but with sufficient exactness for the purpose, by noting the 
 reading of the scale at which one half of the field is blackest 
 when the analyzer is turned a few degrees from zero. 
 
 If the lamp and instrument are properly adjusted in the 
 manner described, bright extraneous light excluded, and 
 the direct rays of the blue light of the flame cones of the 
 lamp cut out of the field by a diaphragm, as they are in 
 every properly designed lamp, no error will be introduced 
 in readings certainly as great as 35 within the limit of 
 precision (V) of the ordinary laboratory instrument. 
 
 These notes on the Laurent polariscope apply also to 
 the shadow instruments using the Jellet-Cornu prism and 
 
NOTES APPLYING TO SPECIAL INSTRUMENTS 71 
 
 the Lippich polarizer, except what bears obviously on the 
 manipulation of the Laurent shadow device for changing 
 the light intensity. The Duboscq rotatometers usually 
 have an angle of 5 between the planes of polarization of 
 the two halves of the prism, corresponding to 2.5 for the 
 half angle measured as described above. 
 
 The Landolt-Lippich Polariscope. This instrument is 
 made in a variety of forms, and is especially designed for 
 exact physical measurements. The elaborate measuring 
 devices used on the larger instruments for determining 
 optical rotation to .001 need not be considered here, as 
 they are in principle identical with those used in precise 
 physical and astronomical measurements by graduated 
 circles. Some of these instruments have the circle divided 
 into 400 divisions, instead of 36O . 1 
 
 1 The large Landolt-Lippich polariscopes have the scale which moves with 
 the analyzer usually graduated directly to tenths of a degree. The intervals 
 less than tenths are determined in thousandths by a " filar micrometer." This 
 is a device for measuring the distance that the reference mark (shown in the 
 field of the micrometer eyepiece as a notch at the side of the graduations) 
 lies from the scale line. This is done by moving two parallel cross hairs along 
 the scale by means of a finely threaded screw, the distance traversed being 
 shown on a drum graduated into 100 parts, which revolves with the screw. A 
 complete revolution of the drum (screw) moves the cross hairs exactly one 
 tenth of a degree on the scale, or the distance between two scale lines. Hence, 
 the reading of the micrometer drum when it is set so that a scale line is ~nid 
 way between the cross hairs when taking the zero error must be subtracted 
 from the reading of the drum when it is similarly set for determining the 
 desired rotation value. The reading of the drum obviously gives the hun- 
 dredths and thousandths of a degree. The readings are more conveniently 
 made if the micrometer is set so that the drum reading is zero when the two 
 cross hairs are symmetrically placed relative to the notch (most accurately 
 determined by first moving the main scale till a long graduation line lies 
 exactly in the notch). Then the readings of the drum directly express the 
 interval in thousandths for each reading after the manner of a vernier. This 
 adjustment can be made by gently moving the drum on the axis of the screw 
 
72 NOTES APPLYING TO SPECIAL INSTRUMENTS 
 
 The illumination of the field of the Lippich polariscope 
 must be adjusted with great care, to prevent surface reflec- 
 tion from the small " half prism " of the shadow device. 
 If the angle of the polarizer is changed during a series of 
 observations, it will be necessary to take new zero readings 
 or bring the analyzer again into zero adjustment by means 
 of the device provided for this purpose. 
 
 The Landolt-Lippich polariscope, when used to measure 
 specific rotations for yellow light (" D ray "), has the rays of 
 a sodium chloride lamp passed through a " Lippich sodium- 
 light filter" consisting of two absorption cells, the first, I 
 decimeter long, containing a 6 per cent solution of potas- 
 sium bichromate, the second, . 1 5 decimeter long, containing 
 a solution of uranous sulphate, U(SO 4 ) 2 . This, according 
 to Landolt, is prepared by dissolving 5 grams of uranyl 
 sulphate in 100 cubic centimeters of water ; 2 grams of zinc 
 powder are added, and then 3 cubic centimeters of sul- 
 phuric acid, gradually, in three successive portions. Air 
 is excluded from the flask, which is allowed to stand six 
 hours till the solution has settled. The solution is then 
 filtered into the cell with as little exposure to the air as 
 practicable. The cell must contain as little air as possible 
 and be tightly closed. It is said that this solution will 
 keep a month or more. The bichromate solution takes out 
 most of the blue and green rays, the dark green uranium 
 
 while the latter is held stationary by the milled head, as the drum is movable 
 on a friction bearing. 
 
 The micrometers on opposite sides of the scale disk can be brought into 
 adjustment to directly indicate the readings a and a + 1 80 respectively, by 
 setting the notches by a screw on the end of the micrometer box opposite to 
 the drum. When thus adjusted the large Schmidt and Hansch instruments 
 rarely show differences of .002 in opposite quadrant readings at any part of 
 the scale. 
 
NOTES APPLYING TO SPECIAL INSTRUMENTS 73 
 
 solution taking out the rest, as well as practically all of 
 the red end of the spectrum. The resulting filtered light 
 has, according to Landolt, a wave length of .00058932 mil- 
 limeter, which represents the wave-length mean of the two 
 D lines. In consequence, the rotation values are not 
 strictly comparable with those of the Laurent and other 
 polariscopes using sodium light filtered through a bichro- 
 mate section, being about .2 per cent greater. 1 
 
 The Wild Polaristrobometer. This instrument is little 
 used in this country, owing to its unusual end point, not 
 readily distinguishable by an inexperienced observer, and 
 the clumsier arrangement of the apparatus necessitated by 
 the rotation of the polarizer instead of the analyzer. The 
 polariscope is capable of precise measurements, however, 
 when skillfully manipulated. As already stated, the rota- 
 tion of the polarizer(Z)) is in the reverse direction to the rota- 
 tory effect of the optically active substance, but in the same 
 direction as the pinion (C) moves by which the observer 
 rotates the prism. The field, except very near the end 
 point, appears as a yellow disk covered with sharply de- 
 fined, black, horizontal lines like a grating. As the 
 polarizer is turned slowly, and the end point is reached, 
 these lines disappear, as if rubbed out by an eraser, in 
 a broad band which moves across the field. The end 
 
 - In the writer's experience, the Landolt -Lippich polariscope gives much 
 more unreliable results than the Laurent, if a bichromate solution alone is 
 used as a ray filter. The Lippich polarizer seems much more sensitive to the 
 extraneous rays present in the sodium flame than the Laurent, and in conse- 
 quence varies its end point by several hundredths of a degree with slight 
 changes of intensity of the flame, under identical conditions, in fact, where 
 the Laurent gives constant readings. With the Lippich ray filter, the Lan- 
 dolt-Lippich readings are constant at constant temperature. Hence, for 
 general laboratory purposes, the Laurent polariscope is more suitable. 
 
74 
 
 NOTES APPLYING TO SPECIAL INSTRUMENTS 
 
 point is taken as the position of the band in the middle 
 of the field when the unextinguished lines of the grating 
 are symmetrically distributed on each side of two cross 
 hairs. The blank appearance at the end point occurs 
 within a very small angle of rotation, and consequently 
 
 A. Eyepiece. 
 
 FIG. 17. WILD POLARISTROBOMETER. 
 
 B. Telescope for reading scale (K). S. Mirror for illuminating scale. 
 
 is so rapid, as the polarizer is turned, that the inexperi- 
 enced observer might overlook it altogether. The end 
 point repeats itself every 90, but the appearance of the 
 field at each end point is not exactly the same, the blank 
 band crossing the field at a different angle in each case. 
 
 The Wild polaristrobometer uses a salt flame without any 
 ray filter. 
 
NOTES APPLYING TO SPECIAL INSTRUMENTS 
 
 75 
 
 B. QUARTZ-WEDGE SACCHARIMETERS 
 
 The Half-shade Saccharimeter. This is the standard 
 instrument in use to-day. The general method of focus- 
 ing has already been discussed under General Notes. 
 The mean error of this instrument when the illumination 
 is properly adjusted and the observer expert, is about .02 
 of a scale division, but under the usual conditions of using 
 
 JP 
 
 FIG. 18. HALF-SHADE SACCHARIMETER, WITH DIAGRAM OF OPTICAL 
 
 PARTS. 
 
 F t E t G. Quartz compensator. K. Reading glass of scale. 
 
 H. Adjustment device for rotating analyzer. M. Pinion for moving compensator. 
 
 J. Eyepiece. O. Position of Jellet-Cornu prism. 
 
 N. Condenser. 
 
 the saccharimeter it is somewhat greater. The light should 
 fill the field uniformly, and not pass too obliquely through 
 the Jellet-Cornu prism (whose position in the instrument is 
 indicated at O\ or the surface of the prism with its bisect- 
 ing joint is too sharply defined (as well as any dust that 
 may be on its surface). The lamp and condensing lens of 
 the saccharimeter, the latter adjustable in a sliding sleeve 
 (N\ should be arranged to pass the rays practically parallel, 
 
76 NOTES APPLYING TO SPECIAL INSTRUMENTS 
 
 or slightly convergent. Landolt recommends that the 
 condensing lens be so placed relative to the lamp that 
 it focuses on the analyzer diaphragm. 1 The field will 
 then be always uniformly illuminated, with the surface 
 of the prism practically invisible, the bisecting line show- 
 ing very faintly at the end point. 
 
 Not infrequently, at the zero end point, the field will not 
 appear quite uniform, one half having a faint bluish tint, 
 while the other appears faintly brown. This is caused by 
 a slight displacement of one of the prisms, and can be 
 corrected by slightly rotating the analyzer by means of 
 the adjustment provided for the purpose. In the older 
 instruments this is done by a key, which will be found in 
 the instrument box, and which fits a pinion (H) on the under 
 side of the eyepiece tube. This pinion turns a gearing 
 that revolves the analyzer. The newer instruments have 
 a somewhat different device. On each side of the eye- 
 piece tube (J) there are two steel screws with projecting 
 heads. These screws have conical points which bear eccen- 
 trically on the edges of two holes bored in a rotating sleeve 
 which carries the analyzer. By loosening both screws, 
 and then turning one or the other down slightly, the effect 
 is to turn the sleeve in a direction depending of course 
 on which screw is turned, the rotation resulting from 
 the pressure of the coned point against the side of the 
 hole in the sleeve. After the analyzer is turned to correct 
 adjustment, the screw which was not used to turn the 
 sleeve is very carefully tightened till it just bears, in 
 order to fix the analyzer in position. Extreme care should 
 
 1 This applies only to the latest type of half-shade saccharimeters fitted 
 with the Lippich polarizer and a specially constructed condenser. 
 
NOTES APPLYING TO SPECIAL INSTRUMENTS 77 
 
 be exercised in making this adjustment, as it is one of deli- 
 cacy. The method of adjusting is as follows: The prism 
 is turned, very slightly, and the wedge moved by the pinion 
 (M) till the field is as evenly tinted as possible. If the 
 disparity of tint at the end point is diminished, turn the 
 analyzer farther in the same direction till no difference in 
 tint appears when the wedges are adjusted to even shade. 
 If the disparity of tint increases on turning the prism, turn 
 in the opposite direction, each time always adjusting the 
 wedge for a field of uniform shade (being also as even a 
 tint as possible), independently of the scale reading. 
 After the field is both evenly tinted and shaded at the 
 end point, the scale may be brought into adjustment by 
 setting the vernier zero to the scale zero by means of the 
 key found in the box. This key fits on an adjustment 
 pinion at the left end of the vernier scale (not shown in 
 cut). 
 
 Many observers prefer to correct for any disparity of 
 tint at the end point by using an absorption cell of potas- 
 sium bichromate solution. Many of the modern instru- 
 ments are provided with such an absorption cell, which 
 fits into the polarizer end of the saccharimeter. This 
 cell absorbs the blue rays, which make the most disturb- 
 ance, and gives an agreeably tinted field of uniform shade 
 and tint at the end point even if the prisms are slightly 
 out of adjustment. This cell is necessary when solutions 
 of a slightly different dispersive power from quartz are 
 polarized, commercial " glucose," for instance. In fact, if 
 white light is used, there will be a slight disparity of tint 
 at high rotations, even with cane-sugar solutions, as the 
 dispersive powers of cane sugar and quartz differ some- 
 
78 NOTES APPLYING TO SPECIAL INSTRUMENTS 
 
 what at the blue end of the spectrum. A piece of brown 
 (carbon) tinted glass is a very good substitute for the bi- 
 chromate cell, although it does not cut off the blue rays 
 quite as effectively. It may be well to note again the 
 considerable error caused by varying temperature. For 
 accurate work it is necessary that the saccharimeter be 
 exposed for at least an hour to a temperature practically 
 uniform with that at which the readings are made. The 
 exact graduation should be established by means of stand- 
 ard quartz plates of known values, since instruments are 
 graduated by at least two systems, as has already been 
 noted, one based on the Mohr cubic centimeter of 17.5, 
 the original Ventzke and established commercial stand- 
 ard ; the other, the official standard of the United States 
 Custom House, based on true-cubic-centimeter volumes. 1 
 
 The Triple-shade Saccharimeter. This instrument dif- 
 fers from the standard commercial saccharimeter only in 
 the end-point device, which is the Lippich triple-prism 
 polarizer, the essentials of which are a large Nicol prism, 
 and two smaller Nicols placed close to the large Nicol, 
 between it and the analyzer. These two smaller "half 
 prisms," as they are called, have their vibration planes 
 parallel to each other, but at a slight angle to that of the 
 larger Nicol. The light from this polarizer passes through 
 the circular opening of a diaphragm in such a way, and 
 
 1 Apparently some saccharimeters, especially the later ones, are graduated 
 to give exact percentages of cane sugar at all concentrations. Such scales are 
 not strictly proportional to the quartz rotation values, as the specific rotation 
 of sugar increases slightly with diminishing concentration. Hence the sur- 
 face of the " wedges " must be curved or the divisions vary in size. Many 
 of the newer instruments, graduated for true cubic centimeter flasks, when 
 compared with the Ventzke graduation, show at the 100 point the ratio, 
 I. ooooo: 1.00234, Dut lu tne middle of the scale, i.oooo : 1.0033. 
 
NOTES APPLYING TO SPECIAL INSTRUMENTS 
 
 79 
 
 FIG. 19. 
 
 the half prisms are so arranged, that the field is trisected 
 vertically by the edges of the two half prisms. The dia- 
 gram shows the position of the prisms relative to the field 
 of the instrument. The circle repre- 
 sents the field defined by the diaphragm 
 opening; A and B show the positions 
 of the half prisms and C that of the 
 large Nicol. Then, if the vibration 
 planes of the two half prisms are 
 taken parallel to aa 1 and bV ', and cc^ 
 inclined at a small angle to aa f or 
 bV , represents the vibration plane of the large Nicol C, 
 the field will be equally illuminated when the vibration 
 plane of the analyzer is at right angles to a line bisecting 
 the angle made by the vibration plane of the Nicol C 
 and that of either half prism A or B. The diagram in 
 plan shows the position of the prisms relative to the light 
 
 passing through the instru- 
 ment along its axis in the 
 direction shown by the 
 arrow through the lens L, 
 the diaphragm being at D. 
 It will be noticed that the 
 half prisms are slightly canted longitudinally. This is to 
 insure a sharp focus on the edge of the prism, so that its 
 image at the end point will be a faint hair line. 
 
 Obviously, the light effect in the two side sections of 
 the field is the same when the plane of the light is rotated, 
 the contrast being between these and the central section, 
 instead of in the halves of the field as in the half-shade 
 saccharimeter. Owing to the agreeable effect of the 
 
 FIG. 20. 
 
80 NOTES APPLYING TO SPECIAL INSTRUMENTS 
 
 triple-shade field, this instrument has become very popu- 
 lar. However, on account of the complication and deli- 
 cacy of the prism combination, it is much more liable to 
 get out of adjustment, the exact parallelism of the two 
 half prisms being difficult to maintain. It is therefore 
 doubtful whether, under the ordinary conditions of its use 
 in the sugar laboratory, it really gives readings of greater 
 precision than those of the half-shade saccharimeter, espe- 
 cially when the latter has its illuminating apparatus ad- 
 justed to give the best field for accurate reading. 
 
 Variations in temperature will apparently affect the 
 half -prism adjustment, as well as any shock or jar to the 
 instrument. The result is that the field at the end point 
 will not be perfectly evenly illuminated, but one or the 
 other of the side sections will show a faint shading. 
 There will be, in consequence, two end points, depending 
 on which side of the field is evenly illuminated with the 
 central section. Usually this disparity is less than .1 of 
 a scale division, but the precision of the instrument is low- 
 ered by that amount, unless the observer goes through the 
 tedious process of taking the average of the readings by 
 each end point, and thereby halves his error. This defect, 
 however, is an annoying one and of course does away with 
 any superiority of precision over the simpler half-shade 
 type. 
 
 If the theory of the Lippich polarizer is thoroughly 
 understood, any one experienced in working with delicate 
 instruments can adjust the half prisms to parallelism in the 
 following manner : Remove the screws in the metal sheath 
 of the enlarged part of the tube containing the polarizer. 
 Take the sheath off, which will expose the half prisms in 
 
NOTES APPLYING TO SPECIAL INSTRUMENTS 
 
 8l 
 
 their brass mountings. Both of these mountings can be 
 rotated through a small angle, and one is provided with 
 coned-screw adjustments for making a very small rotation, 
 exactly as described in the Notes on the Half-shade Sac- 
 charimeter. If the screws of the slotted guides holding 
 
 FIG. 21. DOUBLE-WEDGE, TRIPLE-SHADE SACCHARIMETER WITH DIAGRAM 
 OF OPTICAL PARTS. 
 
 t , N~ z . Half prisms. 
 
 Polarizer. 
 
 the mounting of the prism to be rotated are loosened, then 
 the delicate adjustment to parallelism can be made with the 
 coned screws, in a similar way to that already described. 
 When the field shows perfectly uniform illumination at the 
 end point, the screws in the guide slots are gently tight- 
 ened to hold the mounting in position. Considerable skill 
 and patience are required to make this adjustment. Great 
 
82 NOTES APPLYING TO SPECIAL INSTRUMENTS 
 
 care should be taken to move only those screws which 
 have to do with this adjustment, as there are other screws 
 which rotate the prism longitudinally. 
 
 The newer triple-shade as well as half-shade saccha- 
 rimeters have the scale illuminated by means of a small 
 mirror over the scale, which throws the light of the main 
 lamp of the saccharimeter down through a ground glass 
 upon the scale. This obviates the necessity of a separate 
 scale light. If the saccharimeter is screened from the 
 light by a partition, or placed in a hood, care should be 
 taken to have the hole through which the light passes 
 large enough to allow a diagonal ray to the mirror. A 
 mirror of any kind fastened to the top of the hood by 
 means of a stiff bent wire, when properly placed, works 
 well with the older form of scale apparatus. A cheap, 
 silvered-glass concave reflector, such as used with an ordi- 
 nary kerosene lamp, works excellently. 
 
 The Soleil-Ventzke-Scheibler Transition-tint Saccharime- 
 ter. This instrument, which was the standard commer- 
 cial saccharimeter less than fifteen years ago, is now 
 almost completely replaced by the half-shade type. It 
 takes considerable practice to get high precision in obser- 
 vations with a transition-tint saccharimeter, but an expert 
 with a good eye for color can read the tint transition as 
 accurately as the half-shade end point, unless possibly in 
 the case of very highly colored solutions, such as low- 
 grade molasses. The errors of reading such solutions are, 
 however, much less than others peculiar to polarizing such 
 products, to be discussed later. The normal weight used 
 with this instrument (26.048 grams) and in fact all the 
 working parts, except those which have to do with the 
 
NOTES APPLYING TO SPECIAL INSTRUMENTS 
 
 special end-point device, are identical with those of the half- 
 shade saccharimeter. 
 
 The method of using this instrument is as follows : 
 Focus the eyepiece (_/) on the transition-tint plate, which 
 will appear as a party-colored disk of two contrasting 
 colors, each occupying one half of the field on each side of 
 a central vertical line. Turn the scale to zero, or till both 
 halves of the field are of the same tint ; then turn the button 
 
 F E 
 
 E 
 
 FlG. 22. SOLEIL-VENTZKE-SCHEIBLER TRANSITION -TINT SACCHARIMETER. 
 
 A. Shows position of Nicol of tint 
 
 producer. 
 
 B. Position of quartz plate of tint 
 
 producer. 
 
 C. Position of polarizer. 
 
 D. Position of transition-tint plate. 
 
 F y , G. Quartz-wedge compensator. 
 
 H. Adjustment device of analyzer. 
 
 y. Eyepiece. 
 
 K. Reading-glass of scale. 
 
 L. Pinion for setting sensitive-tint producer. 
 
 M. Pinion for moving wedge. 
 
 on the end of the long rod (Z) at the right of the eyepiece, 
 which turns the Nicol of the " sensitive-tint producer," till 
 a suitable tint is produced in the field for a background 
 against which the eye can most readily distinguish the 
 delicate rose tint which appears in one or the other half of 
 the field when the wedge is almost at the end-point posi- 
 tion. The tint chosen varies with different observers. It 
 is always a very pale one, flesh or pearl, practically white. 
 The end point shows both halves of the field evenly tinted 
 
84 NOTES APPLYING TO SPECIAL INSTRUMENTS 
 
 with this sensitive color, but at the slightest turn of the 
 wedge pinion a pale rose flush will appear in one half of 
 field or the other. The light from the lamp should be 
 soft and diffused, not too bright. In taking zero observa- 
 tions, many place a tube full of water in the instrument to 
 soften the light. As the eye becomes fatigued quickly, 
 and loses its maximum sensitiveness for distinguishing 
 slight changes in tint in a few moments, rapid readings 
 should be made. All glaring outside light, especially if 
 colored, should be excluded, the observer being in com- 
 parative darkness. When a colored solution is placed in 
 the instrument, the sensitive tint must be again adjusted 
 till the color is obtained which proves most sensitive for 
 observing the end-point transition. With highly colored 
 solutions of molasses or molasses sugars, the transition 
 change appears as a shadow, owing to the practically 
 complete absorption of the tint by the deep brown-red of 
 the caramel substance of the molasses. 
 
 Occasionally, especially in an old instrument, the prisms 
 become displaced sufficiently to affect the sensitiveness of 
 the readings, the field not appearing perfectly uniform at 
 the end point. The quickest and surest way to bring the 
 instrument in adjustment is to remove the quartz-wedge 
 compensation entirely, and then adjust the analyzer till the 
 field is evenly tinted. As in the adjustment of the analyzer 
 in the half -shade saccharimeter, this is done by means of a 
 key which turns a pinion (//") on the under side of the eye- 
 piece tube. To remove the compensator, slip out the 
 movable wedge (E\ unscrew the brass plate carrying the 
 fixed wedge (F) and the vernier scale, and finally, remove 
 the left-rotating quartz section which is the last optical 
 
NOTES APPLYING TO SPECIAL INSTRUMENTS 85 
 
 part on this end of the instrument going toward the 
 polarizer. This is done by unscrewing the brass ring of 
 the mounting (G) from the trough side. 
 
 The Soleil-Duboscq Transition-tint Saccharimeter. - 
 This instrument has been entirely superseded in commer- 
 cial work by the improved modern types of quartz-wedge 
 saccharimeters. The wedges of the Duboscq instruments 
 are well made, however, and in the hands of a skillful 
 worker it is a precise instrument to at least .2 of a divi- 
 sion, an accuracy sufficient for many laboratory measure- 
 ments. A conscientious and painstaking observer with a 
 good eye for color can make efficient use of such a saccha- 
 rimeter, since its deficiencies are largely those of incon- 
 venience and difficulty of manipulation, and these can be 
 supplemented by exercising a correspondingly greater skill 
 in working with the instrument. The young chemist is 
 apt to condemn too hastily any laboratory instrument 
 which is not of modern type, when a little practice and a 
 study of the nature and magnitude of the errors of analy- 
 sis would show that such apparatus fulfills all the require- 
 ments of the work at hand. Of course, in the case of large 
 commercial laboratories, where accuracy with speed and 
 uniform trade methods are the leading considerations, the 
 standard modern saccharimeter is indispensable. 
 
 The fundamental principles of the working of the Du- 
 boscq-Soleil saccharimeter are identical with those of the 
 Soleil-Ventzke, but the details of the apparatus are con- 
 siderably different. Both wedges of the compensator are 
 moved by the pinion past each other, instead of one being 
 fixed as in the modern instrument. The scale, which is 
 graduated for a normal weight of 16.35 grams, or what 
 
86 NOTES APPLYING TO SPECIAL INSTRUMENTS 
 
 was taken as the equivalent of the rotation of a millimeter 
 section of quartz, has no vernier, and reads from right to 
 left, the fractions being estimated by aid of a hand magni- 
 fier. The sensitive-tint producer is in the eyepiece, 1 which 
 latter in consequence moves in a slotted guide to avoid any 
 disturbance of the tint in focussing. The Nicol for pro- 
 ducing the sensitive tint can be rotated through a half 
 circle by means of a milled ring on the eyepiece tube. 
 
 A trough can be made very cheaply which will fit into 
 the instrument and so allow the use of the more convenient 
 modern tubes, which are of smaller diameter. 
 
 Double-wedge Saccharimeters. In these instruments, 
 the scales read to the left, the figures of the " working 
 wedge " scale being in black and those of the " control 
 wedge " in red. The pinion head of the " control wedge " 
 is also of a different color from that of the "working 
 wedge," and placed at a different level to avoid confusion. 
 Double-wedge scales have read from right to left in all 
 saccharimeters of this type which have come under the 
 author's notice. The scales do not have minus gradua- 
 tions, as left-rotating solutions can be read by using the 
 control wedge as the working wedge. When a double- 
 wedge saccharimeter is in adjustment, and no optically 
 active substance is in the instrument, the end point is 
 always given when the wedges are so adjusted that both 
 scales read alike, independently of the numerical value of 
 the reading. (See Figures 10 and 21.) 
 
 1 It is interesting that the illustration of a saccharimeter in Clerget's original 
 article on sugar-testing, written in 1849 (Ann. Chim. Phys. 26 (3), 175), 
 shows an arrangement of tint producer identical with the modern instrument 
 of Scheibler. 
 
POLARIZATION OF CANE SUGAR. GENERAL 
 COMMERCIAL METHODS 
 
 Sampling. In most commercial analyses the sugar is 
 determined as a per cent by weight of the original product 
 as it is bought and sold in the market. The sample which 
 the chemist polarizes must be strictly representative of the 
 total lot of sugar, which may amount to several thousand 
 tons. The sampling of such large lots of sugar entails 
 much labor, and in the case of raw sugars is usually done 
 by men specially trained for this work. Great care has to 
 be exercised, as it is by no means easy to get a representa- 
 tive sample. Not only is sugar bought and sold on its 
 percentage value, but the government assesses import 
 duties based on the polarization, which may amount to 
 from 30 to 50 per cent of the total value of the cargo. 
 Raw sugar reaches the market in diverse forms of package. 
 The old-fashioned "open kettle" or muscovado sugar, 
 some of which is still shipped, comes in hogsheads of 
 from 1500 to 1650 pounds. The modern West Indian 
 sugar houses usually ship in burlap bags of 300 pounds. 
 The Hawaiian sugar comes in 125-pound bags. The 
 Javan sugar is packed in cylindrical bamboo crates, hold- 
 ing about 700 pounds. Some sugar is packed in wooden 
 boxes, and the primitive palm sugars of the East come in 
 bamboo "mats." 
 
 The sampling of raw sugars is especially difficult be- 
 cause the product contains considerable moisture from the 
 
 87 
 
88 POLARIZATION OF CANE SUGAR 
 
 molasses, which is retained by the spongy mass of crystals, 
 the amount varying greatly with the quality of the sugar. 
 This molasses tends to drain from the upper layers of the 
 package and collect at the bottom. Most sugars exposed 
 to the air rapidly lose their moisture. In consequence, 
 sugar samples taken from different parts of a package 
 may differ appreciably in polarization. The method of 
 sampling found most satisfactory in practice is to thrust 
 a long metal tube, known as a " trier," through the whole 
 bulk of the package, in a line extending diagonally from 
 the top of one side to the bottom of the other. 1 By rotat- 
 ing the trier, it is filled with sugar its entire length. 
 
 In this way each package, or a certain percentage of 
 the packages, of the cargo is sampled, and the sugar from 
 the sampling transferred as quickly as possible to a cov- 
 ered can or metallic box to prevent drying. After a 
 thorough mixture of this large sample, small samples are 
 taken from it which are put into tin boxes holding half a 
 pound or so. These are tightly covered and often sealed 
 by dipping the box in paraffin. It is in this form that the 
 samples go to the laboratory. Molasses or sirups are sam- 
 pled by running a stick into the bunghole of the barrel or 
 hogshead and draining off the adhering liquid into a bottle. 
 
 Method of Polarizing. The commercial method of polar- 
 izing is as follows : Mix the sample thoroughly, breaking 
 up all lumps. This is best done by pouring out the con- 
 tents of the box upon a sheet of ordinary brown calendered 
 wrapping paper, or, better, a sheet of plate glass. Weigh 
 out the normal weight of sample in the tared German- 
 
 1 Bags and baskets of " centrifugal " sugars are sampled by driving the trier 
 in at the side so as to sample the central contents. 
 
POLARIZATION OF CANE SUGAR 89 
 
 silver dish provided for the purpose, weighing to .005 
 gram. The preparation of the sample and the weighing 
 should be done as quickly as possible and the remainder 
 of the sample returned to the covered box at once to avoid 
 change from evaporation. Pour about 50 cubic centime- 
 ters of water, at room temperature, into the dish, and stir 
 up the crystals from the bottom with the little metallic 
 pestle provided for the purpose. It is usually not neces- 
 sary to grind the sample with the pestle in dissolving, as 
 this does not materially assist solution, 1 and wears the dish. 
 Pour off the solution into a loo-cubic-centimeter graduated 
 flask, taking especial care not to pour out any undissolved 
 sugar. Very fine crystals are often carried into the flask 
 if care is not taken to prevent it, and, settling to the bot- 
 tom, remain undissolved. Add a little water to dissolve the 
 rest of the sugar in the dish. There is usually left a slight 
 residue of insoluble matter, sand or dirt. 
 
 As aqueous solutions of raw sugars are practically opaque 
 from the presence of albuminoid and other vegetable 
 extractive matter in a colloidal state, it is necessary to use 
 some precipitant to clarify the solution in order to get it 
 into a suitable condition to polarize. A solution of basic 
 lead acetate of a density of 1.25 is the clarifier almost uni- 
 versally used. 
 
 After the solution has been entirely washed into the 
 
 1 Another method of solution is to wash the sugar through a wide-mouthed 
 funnel directly from the dish into the flask by means of a wash bottle or other 
 convenient jet apparatus. The flask is filled about three quarters full, and is 
 shaken till the sugar is dissolved. This is the official German method. With 
 a large number of samples it is quicker, as the flasks can be placed in a 
 shaking machine and all shaken at once. With a few it is slower, but it has 
 the advantage that the weighing dishes are not worn by any grinding. 
 
90 POLARIZATION OF CANE SUGAR 
 
 flask, allow it to stand a few minutes so that any solution 
 in the neck may drain off, add 2 cubic centimeters of basic 
 lead acetate solution, and make up to the graduation mark 
 with water. If foam prevents the reading of the meniscus, 
 add a drop of ether, or better, spray a little ether into the 
 flask with an atomizer. This will immediately dissipate the 
 foam. Shake the solution and filter through a dry filter into 
 a (dry) cylinder, rejecting the first few drops. Cover the 
 funnel with a watch-glass to avoid evaporation. 
 
 The amount of lead acetate solution necessary for clari- 
 fication varies with the nature of the sugar polarized. 1 No 
 exact rule can be given. Use as little as possible. If too 
 little lead solution is used, the clarification is incomplete ; 
 if too much, the solution soon clouds after filtering from the 
 formation of basic salts or carbonate. If the right amount 
 of lead has been added, and thoroughly mixed through the 
 solution, after a few minutes a distinct coagulation will be 
 noticed, the particles gradually settling out and leaving at 
 the surface a comparatively clear solution. The addition of 
 about 2 cubic centimeters of " alumina mixture" a solu- 
 tion of alum almost completely precipitated by ammonia 
 so as to be practically a creamy mixture of aluminum 
 hydrate in ammonium sulphate solution assists clarifica- 
 tion and removes any excess of soluble lead. 2 A 5 P er 
 
 1 Another method of clarification has been proposed very recently by 
 Home (/. Am. Chem. Soc., XXVI, 186), which is designed to obviate the 
 effect of the volume of the precipitate on the concentration. In this method 
 the solution is made up to 100 cubic centimeters previously to clarifying. 
 A sufficient quantity of basic lead acetate in powdered form is added and the 
 solution filtered. 
 
 2 This is important if the solution is to be inverted by the Clerget method 
 (described in the next chapter), to prevent removal of hydrochloric acid by 
 the lead in the filtrate, 
 
POLARIZATION OF CANE SUGAR 9 1 
 
 cent solution of common salt is also excellent for the latter 
 purpose. 
 
 Dark solutions, as from molasses, sometimes require 
 either diluting or the use of the i -decimeter tube. 1 Occa- 
 sionally the solution is decolorized by placing a gram or so 
 of prepared bone black in the dry filter. Owing to the 
 initial absorption of sugar by the black, the first 30 cubic 
 centimeters of the filtrate should be rejected. Decoloriza- 
 tion by bone black should only be used as a last resort. 
 Highly refined sugars, such as granulated, usually need no 
 clarification other than simple filtration. Often, when a 
 precipitant is necessary, the alumina mixture alone suffices. 
 
 Polariscope Tubes. In filling tubes avoid air bubbles. 
 These obviously cut off the field and impair the definition 
 unless very small, when they need not be considered. 
 Rinse the tube twice with the solution before filling. 
 
 Before placing a tube in the instrument wipe carefully, 
 and see that the outside of the cover glasses is clean and 
 free from moisture. If objects cannot be seen clearly and 
 without distortion when looking through the tube, it is use- 
 less to try to make a polariscope reading, and it should be 
 refilled. If the tube is handled much, the heat of the hand 
 will temporarily disturb the solution, causing a turbidity 
 which will soon clear. 
 
 In placing caps on polariscope tubes, note that the number 
 
 1 Sawyer (y. Am. Chem. Soc., 27 (July)) shows by many experimental data 
 that it is better to polarize low-grade molasses in fifth normal solution 
 (26.048 grams in 500 cubic centimeters). Aside from the greater con- 
 venience in making up the solution and the saving of eyesight in reading the 
 lighter colored filtrate, less than one half as much basic lead acetate is nec- 
 essary ; hence, the errors due to clarification are correspondingly decreased, 
 as is the effect of the bulk of the precipitate in the larger volume of solution. 
 These advantages more than compensate for the increased errors of reading. 
 
92 POLARIZATION OF CANE SUGAR 
 
 or symbol on the cap corresponds with that on the tube. 
 This will prevent jamming or sticking of the caps. The 
 friction caps of the Landolt tubes should be firmly seated 
 by pressing them on with a rotary motion. Screw caps 
 should be screwed on firmly and then very slightly slack- 
 ened, so that the pressure on the cover glass is from the 
 expansion of the soft rubber washer which is a necessary 
 fitting in the cap of both types of tube. See that this 
 washer is always in the cap. 
 
 After using, all apparatus that has been in contact with 
 solutions should be thoroughly washed with running water 
 and placed in a rack to dry (not wiped). This will insure 
 a constant supply of clean dry apparatus. Take care to 
 wash the brasswork at the ends of the tubes, especially 
 the Landolt, or the caps will stick. After washing, leave 
 cover glasses out, but place caps on the ends of the tubes 
 so as to protect the ground surfaces from being chipped 
 by any chance knock. The lead used for clarifying in 
 sugar solutions gradually clouds glassware. Remove by 
 occasional washing in hydrochloric acid. If cover glasses 
 stick in the caps, force them out with a clean stick of wood ; 
 do not use metal or glass. Care should be exercised to 
 avoid scratching the cover glasses in any way. Scratched 
 cover glasses should not be used. Glass polariscope tubes 
 are preferable to metal ones from their greater cleanliness 
 and because they are less affected by temperature changes. 
 
 The brass mountings at the ends of glass tubes should 
 always be examined before using the tubes, as they occa- 
 sionally work loose and become pushed out so that the 
 cover glasses bear on the brass and not on the ground-glass 
 ends of the tube as they should. By gently heating the end 
 
POLARIZATION OF CANE SUGAR 
 
 93 
 
 of the tube till the resinous cement which holds the mount- 
 ing melts, the brass collar can be pushed back till the ground 
 end of the tube is just exposed, and allowed to cool in this 
 position till the cement hardens. A good quality of seal- 
 ing wax makes a good cement, or better, especially in warm 
 climates, a mixture of litharge and glycerine, which rapidly 
 hardens when gently heated. 
 
 FIG. 23. WATER- JACKETED TUBE FOR POLARIZING AT CONSTANT 
 TEMPERATURE. 
 
 A, Tubulus for thermometer. D. Rubber stopper. 
 
 B, C. Water jacket connections. E. Thermometer. 
 
 F. Air vent for equalizing pressure on liquid in tube. 
 
 Tubes for ordinary laboratory instruments are usviall) 
 made of three lengths, i, 2, and 4 decimeters. The stand 
 ard tube for commercial work is 2 decimeters in length. 
 Tubes used for inversion readings, to be mentioned later, 
 are 2.2 decimeters long and provided with a tubulus for 
 holding sufficient solution in which to immerse a ther- 
 mometer bulb for taking the temperature of the solution in 
 the tube during readings. Preferably such tubes are sur- 
 
94 POLARIZATION OF CANE SUGAR 
 
 rounded by a circulating- water jacket for maintaining con- 
 stant temperature. 
 
 Certain forms of tubes have been designed with an 
 enlarged chamber to trap any air bubbles which might 
 accidentally be introduced into the tube, and keep them out 
 of the optical field of the saccharimeter. With ordinary 
 care in manipulation no such devices are necessary. 
 
 Pellet has devised a " continuous diffusion " tube which 
 by means of tubulature connections can be filled without 
 removing from the saccharimeter. This apparatus is very 
 useful where a large number of polarizations are to be 
 made quickly, as in valuing beets. 
 
 Of course if / is not 2, v not 100, or the weight of sample 
 taken (w f ) not the normal weight (/V), the reading of the 
 saccharimeter will not express directly the per cent of 
 sugar. If, for instance, the weight of sample is other than 
 the normal weight, the percentage will be given by the 
 
 N 
 
 following equation, P = R 7 , where R is the reading, and 
 
 P is the per cent required. 
 
 Manipulation of the Schmidt and Hansch Control Tube. 
 The principles on which the use of this instrument 
 depends in its application to the calibration of saccha- 
 rimeters have already been explained. The method of 
 manipulation is as follows: Extend the tube to practically 
 its full length, insert funnel plug (not shown in cut), and 
 fill with the sugar solution through one end in the same 
 way as a tube of the ordinary type. 1 Remove plug, and 
 shorten the tube a little by moving the pinion (N) slightly. 
 
 1 The tube at the funnel end requires a cover glass larger than the ordinary 
 size. 
 
POLARIZATION OF CANE SUGAR 95 
 
 This will make the solution fill up the plug hole. Put the 
 funnel (7") in place and fill about a quarter full with the 
 solution, taking care not to let air into the main tube when 
 inserting the funnel. It is advisable to pour a few drops 
 of the solution through the funnel before placing the latter 
 in the tube, as this insures displacement of the air in the 
 neck, which might otherwise be forced into the tube. The 
 pinion should work stiffly enough to avoid changing the 
 length of the control tube in handling. Owing to the ab- 
 sorption of the packing of the telescoping joint at C, the 
 
 FIG. 24. CONTROL TUBE. 
 
 control tube must be much more thoroughly rinsed with 
 the solution than an ordinary tube, especially if solutions 
 are changed in calibrating. Obviously, too, the tube must 
 be particularly carefully washed and dried after using. A 
 vented cap should be used on the funnel to avoid evaporation. 
 
 It is vital for accurate work that the temperature be 
 constant during the readings. 
 
 Chemically Pure Sucrose for Standardizing Saccharime- 
 ters. The purest commercial sugar (white granulated or 
 "rock candy") is made up to a hot saturated solution. 
 The sugar is precipitated by pouring the solution into 
 absolute alcohol, and the crystals separated by a small 
 
g6 POLARIZATION OF CANE SUGAR 
 
 centrifugal and washed with the same alcohol. The sugar 
 is then redissolved and the same procedure repeated. The 
 crystals are then dried in a vacuum desiccator and kept in 
 a tightly closed glass vessel. 
 
 Errors of Commercial Polarizations. Besides the errors 
 of polariscope and saccharimetric measurements already 
 discussed, there are others peculiar to the standard com- 
 mercial method, and dependent on the nature of the 
 impurities present in the sugars themselves. Although 
 an immense amount of work has been done in the investi- 
 gation of these errors, yet they are little understood, and 
 practically are ignored in commercial analysis for the chief 
 reason, perhaps, that experience has shown, in the case of 
 the ordinary class of commercial sugars, that the total 
 errors apparently balance each other very closely, with 
 the result that polarizations made at average room tem- 
 perature by the standard commercial methods give with 
 requisite accuracy the per cent of sucrose in the sample. 
 The effect of temperature variation -has already been noted. 
 
 The bulk of the precipitate from the lead clarification 
 has always been neglected in commercial polarizations, 
 being reckoned as part of the solution in making up to 
 volume, partially on the ground that its volume largely 
 results from water of hydration abstracted from the solu- 
 tion. Many investigations have been made to determine 
 the volume of this dried precipitate, as well as in study of 
 the effects of adding to sugar solutions known volumes of 
 material of a nature supposed to be similar to the impuri- 
 ties present in the natural products. None of this work 
 has thrown much light on the question, partially from the 
 difficulty in getting at the exact conditions of the forma- 
 
POLARIZATION OF CANE SUGAR 97 
 
 tion of the precipitate, and also because, in the case of low- 
 grade sugars, where this effect of the precipitate volume 
 is greatest, the lead solution exerts other little-understood 
 influences on the rotation of other impurities present. 
 Therefore, the disturbing effect is the resulta'nt of several 
 influences, varying with the nature of the impurities and the 
 conditions of clarifying. These errors in general seem to 
 increase the polarization, while temperature errors as a rule 
 decrease the readings. Consequently, it is questionable, in 
 the interests of scientific accuracy, whether any correction 
 should be made, in raw sugar polarizations at least, till all 
 the disturbing influences can be accurately controlled. 
 Otherwise nothing is gained in the approach to the true 
 saccharimetric value. As already stated, there has been 
 a general agreement among sugar chemists to make polari- 
 zations at 20. Scheibler first devised a method of " double 
 dilution " to eliminate the effect of the bulk of the precipi- 
 tate. His method, as modified by Wiley, requires two polar- 
 izations to be made, one of a solution made up at the 
 normal concentration, the other at a concentration of twice 
 the dilution, that is, the normal weight of sample dissolved 
 in 200 cubic centimeters of solution, the amount of lead 
 acetate solution added before making up to volume being 
 exactly the same in both cases. It can be shown mathe- 
 matically, 1 that if a represents the reading of the normal 
 solution, and b that of the diluted solution, then the true 
 reading of the solution at an actual concentration of the 
 normal weight in 100 cubic centimeters will be given by 
 
 the formula, R -. - 
 
 a b 
 
 1 Wiley,/. Am. Chem. Soc. 18, 430. 
 
98 POLARIZATION OF CANE SUGAR 
 
 The lower grade raw cane sugars, as also cane juices 
 and sirups, always contain an appreciable amount of the 
 glucose type of sugars. These are to some extent present 
 in the original cane juice, and in part are formed from the 
 decomposition of the cane sugar in manufacture. Whether 
 the glucose sugars from these different origins are identi- 
 cal or not has not been settled by sugar chemists. It is 
 known that the mixture of glucoses from the decomposi- 
 tion of cane sugar have a left-rotatory effect, while there 
 is much evidence that the glucose sugars in commercial 
 cane products are optically inactive. Moreover, it is known 
 that basic lead acetate changes the rotations of these glu- 
 coses, certainly in the case of those which are derived from 
 the decomposition of the cane sugar during manufacture. 
 Although these facts are most suggestive, they have not 
 yet led to any accurate methods of estimation of the errors 
 of polarizations introduced by the action of lead acetate, 
 or their prevention. The addition of acetic acid to break 
 up these levulose compounds is a questionable expedient. 
 
 Beet sugar products, even of low grade, are practically 
 free from reducing sugars, but contain small quantities of 
 a polysaccharide substance known as raffinose. This has 
 a strong specific rotatory power (about 105) and in some 
 cases makes an appreciable error in polarization. 
 
 Errors due to Change in Specific Rotation of Sucrose at 
 Low Concentrations. The specific rotation of cane sugar 
 is not exactly a constant at all concentrations of its aqueous 
 solution, as has already been stated. Hence, the readings 
 of sugar solutions of different concentrations on the sac- 
 charimeter are not strictly proportional to the thickness 
 of the compensating quartz section, if the saccharimeter 
 
POLARIZATION OF CANE SUGAR 
 
 99 
 
 is graduated so that any reading n represents a position 
 of the wedge corresponding to a section of compensating 
 
 quartz of the thickness of quartz compensating at 
 the 100 point. In other words, a quartz-wedge saccha- 
 rimeter whose wedge surfaces are perfect planes and 
 whose scale divisions are equal does not give a perfectly 
 exact reading of the sugar per cent at all parts of the scale. 
 Schmitz has calculated the following table giving the exact 
 saccharimetric value for each division of the saccharimeter : 
 
 READING 
 
 PER CENT 
 
 OF SUGAR 
 
 READING 
 
 PER CENT 
 OF SUGAR 
 
 READING 
 
 PER CENT 
 OF SUGAR 
 
 READING 
 
 PER CENT 
 OF SUGAR 
 
 I 
 
 1. 00 
 
 26 
 
 25.94 
 
 5 1 
 
 50.92 
 
 76 
 
 75-94 
 
 2 
 
 1.99 
 
 27 
 
 26.94 
 
 52 
 
 5^92 
 
 77 
 
 76.94 
 
 3 
 
 2.99 
 
 28 
 
 27-93 
 
 53 
 
 52.92 
 
 78 
 
 77-94 
 
 4 
 
 3.99 
 
 29 
 
 28.93 
 
 54 
 
 53.92 
 
 79 
 
 78.94 
 
 5 
 
 4.98 
 
 30 
 
 29.93 
 
 55 
 
 54.92 
 
 80 
 
 79-95 
 
 6 
 
 5.98 
 
 31 
 
 3-93 
 
 56 
 
 55-92 
 
 81 
 
 80.95 
 
 7 
 
 6.98 
 
 32 
 
 3L93 
 
 57 
 
 56.92 
 
 82 
 
 8i.95 
 
 8 
 
 7.98 
 
 33 
 
 32.93 
 
 58 
 
 57.92 
 
 83 
 
 82.95 
 
 9 
 
 8.97 
 
 34 
 
 33-93 
 
 59 
 
 58.92 
 
 84 
 
 83.95 
 
 10 
 
 9.97 
 
 35 
 
 34.92 
 
 60 
 
 59.92 
 
 85 
 
 84.96 
 
 ii 
 
 10.97 
 
 36 
 
 35.92 
 
 61 
 
 60.92 
 
 86 
 
 85.96 
 
 12 
 
 11.97 
 
 37 
 
 36.92 
 
 62 
 
 61.92 
 
 87 
 
 86.96 
 
 13 
 
 12.96 
 
 38 
 
 37.92 
 
 63 
 
 62.92 
 
 88 
 
 87.96 
 
 H 
 
 13.96 
 
 39 
 
 38.92 
 
 64 
 
 63.92 
 
 89 
 
 88.97 
 
 15 
 
 14.96 
 
 40 
 
 39-92 
 
 65 
 
 64.92 
 
 90 
 
 89.97 
 
 16 
 
 15.96 
 
 4i 
 
 40.92 
 
 66 
 
 65.93 
 
 9i 
 
 90.97 
 
 17 
 
 16.95 
 
 42 
 
 41.92 
 
 67 
 
 66.93 
 
 92 
 
 91.98 
 
 18 
 
 17-95 
 
 43 
 
 42.92 
 
 68 
 
 67.93 
 
 93 
 
 92.98 
 
 19 
 
 18.95 
 
 44 
 
 43.92 
 
 69 
 
 68.93 
 
 94 
 
 93.98 
 
 20 
 
 19.95 
 
 45 
 
 44.92 
 
 70 
 
 69.93 
 
 95 
 
 94.98 
 
 21 
 
 20.95 
 
 46 
 
 45-92 
 
 7i 
 
 70-93 
 
 96 
 
 95.98 
 
 22 
 
 21.94 
 
 47 
 
 46.92 
 
 72 
 
 71.93 
 
 97 
 
 96.99 
 
 23 
 
 22.94 
 
 48 
 
 47.92 
 
 73 
 
 72-93 
 
 98 
 
 97-99 
 
 2 4 
 
 23-94 
 
 49 
 
 48.92 
 
 74 
 
 73-94 
 
 99 
 
 98.99 
 
 25 
 
 24.94 
 
 50 
 
 49-92 
 
 75 
 
 74-94 
 
 100 
 
 IOO.OO 
 
100 POLARIZATION OF CANE SUGAR 
 
 Some of the modern saccharimeters are graduated to 
 give strictly correct readings of sugar per cents at all 
 parts of the scale. Apparently this is done by giving a 
 slightly curved surface to the wedge. 1 
 
 SOME IMPORTANT PAPERS ON ERRORS IN SUGAR POLARIZATIONS 
 
 Welz 1867. Zeit. Ver. deut. rub. zuck. Ind., 17, 489. 
 
 Maumene 1870. Comptes rendus, 69, 1306. 
 
 Scheibler 1870. Zeit. Ver. rlib. zuck. Ind., 20, 218. 
 
 Gill, C. H. 1871. J. Am. Chem. Soc. 
 
 Scheibler 1875. Zeit. Ver. deut. rlib. zuck. Ind., 25, 1054. 
 
 Scheibler 1876. Ibid., 26, 724. 
 
 Schmitz 1878. Ibid., 28, 65. 
 
 Meissl 1879. Ibid., 29, 1034. 
 
 Raffy 1880. Neue Zeit. Ver. nib. zuck. Ind., 4, 241. 
 
 Reichardt and Bittman 1882. Zeit. Ver. deut. rub. zuck. Ind., 32, 
 
 764. 
 
 Sachs 1884. Neue Zeit., 13, 136. 
 Andrews 1889. Tech. Quart., 4, 367. 
 Andrews 1 889. Ibid., 4, 371. 
 
 Weisberg 1891. Bull. Assoc. Chim. Sue. et Dist., 9, 497. 
 Moor 1894. La. Planter, 20, 409. 
 
 Svoboda 1896. Zeit. Ver. deut. rlib. zuck. Ind., 46, 107. 
 Wiley 1896. J. Am. Chem. Soc., 18,430. 
 Pellet 1896. Bull. Assoc. Chim. Sue. et Dist., 14, 131. 
 L. de Bruyn and van Ekenstein 1896. Zeit. riib. zuck., 46, 672. 
 Wiley 1899. J. Am. Chem. Soc., 21, 568. 
 Wiechmann 1903. Columbia Sch. of Mines Quart., 25. 
 Horn 1904. J. Am. Chem. Soc., 26, 186. 
 Sawyer 1905. J. Am. Chem. Soc., 26, 1631. 
 
 1 The readings of a quartz plate on an instrument graduated in the standard 
 Ventzke scale averaged 96.02. The same plate read 95.77 on a saccharimeter 
 graduated for true cubic-centimeter flasks. This gives the ratio, 1.0026: !<. 
 which approximates to the theoretical 1.00234 : I. 
 
 A plate reading, 62.66 on the Ventzke-scale saccharimeter, read 62.45 on 
 the new scale instrument, making the ratio 1.0033 : * This is practically the 
 reading corrected for its true sugar value by Schmitz's table, which is 62.43. 
 
 The readings of the Ventzke scale instrument were proportional to the 
 quartz rotation. 
 
DETERMINATION OF SUCROSE IN PRESENCE 
 OF OTHER OPTICALLY ACTIVE SUB- 
 STANCES (DOUBLE POLARIZATION) 
 
 Fundamental Principles. In the methods of saccha- 
 rimetry, previously described, it has been assumed that 
 sucrose is the only optically active substance in the solu- 
 tions polarized. This is practically true in most commer- 
 cial polarizations, the error rarely exceeding .2 per cent 
 except in low-grade products, where great accuracy in the 
 determination is not so essential. In molasses and sirups, 
 however, the presence of optically active substances other 
 than sucrose may make errors of several per cent in the 
 polarization. 
 
 In most molasses and natural cane sirups the principal 
 disturbing optically active substance present is known as 
 "invert sugar." A brief review of the simpler principles 
 of sugar chemistry may be of aid in understanding the 
 nature of invert sugar and the methods of polarization 
 necessary when it is present. 
 
 Cane sugar, or sucrose, is one of a class of isomeric 
 sugars known as " saccharoses " or "hexose bioses," from 
 the fact that in chemical classification saccharoses may be 
 considered as anhydride combinations of two molecules of 
 glucose sugar. There are but two other biose sugars of 
 present commercial consequence, lactose, or milk sugar, 
 
IO2 DOUBLE POLARIZATION 
 
 and maltose, or malt sugar, the latter being only known 
 in commerce as a constituent of many food products. The 
 formula expressing the percentage composition of these 
 saccharoses is C 12 H 22 O n , or, better expressed from its 
 relation to the glucoses, (C 6 H n O 5 ) 2 O. Aqueous solutions 
 of bioses in the presence of acids or unorganized ferments, 
 which latter are products of animal and vegetable life and 
 known as "enzyms," absorb an equivalent of water, and 
 are converted into two glucose sugars, cane sugar into 
 dextrose and levulose, lactose into galactose and dextrose, 
 maltose into two molecules of dextrose. All of these 
 glucoses are isomeric, having the common proportional 
 formula, C 6 H 12 O 6 , although differing in molecular struc- 
 ture and in many chemical characteristics. This hydra- 
 tion of a saccharose to a glucose sugar, which is known 
 as "hydrolysis," can, therefore, be expressed by the fol- 
 lowing simple equation : 
 
 (C 6 H n 6 ) 2 + H 2 = 2 C 6 H 12 6 . 
 
 The rapidity of hydrolytic action depends on the chemi- 
 cal energy of the acid or enzym, known as the " hydrolyte," 
 and in the case of acids is greatly augmented by increase 
 of temperature. Many salts and metals also have pro- 
 nounced hydrolytic action. This action is always " cata- 
 lytic," as the hydrolyte does not enter into chemical com- 
 bination with the products formed, as far as is known, but 
 remains unchanged. 
 
 Concentrated aqueous sugar solutions, even when shown 
 to be free from acid by ordinary chemical tests, are 
 inverted. appreciably at boiling temperature. On this ac- 
 count, in modern sugar manufacture, all concentration is 
 
DOUBLE POLARIZATION 1 03 
 
 done in vacuum apparatus, so that boiling takes place at 
 a comparatively low temperature (about 50 C.). 
 
 In the case of cane sugar hydrolysis, the following 
 structural formulae express the reaction : 
 
 CH-^ O CH 2 OH HCO CH 2 OH 
 
 /CHOH ^C CHOH CO 
 
 \ CHOH /CHOH CHOH CHOH 
 
 V CH \CHOH" "HOCH CHOH 
 
 CHOH \H CHOH HOCH 
 
 C 2 HOH CH 2 OH CH 2 OH CH 2 OH 
 
 (sucrose) (water) (dextrose) (levulose) 
 
 [0^=66.5 !>]/>= 52.7 [a]z>=-93 
 
 The resulting mixture of the two sugars, dextrose and 
 levulose, is known as "invert sugar," and the hydrolysis 
 is called "inversion," because of the change in specific 
 rotatory power of the mixture from a dextrorotatory value 
 (-f ) to a levorotatory ( ). The specific rotatory power 
 of sucrose is 66.5 at 20 C., that of dextrose 52.7, and of 
 levulose 93. The specific rotatory power of the result- 
 ant mixture of equal equivalents of these two sugars has 
 become, therefore, about 20. It will also be evident why 
 these glucose sugars have received the names they bear. 
 
 All cane molasses and sirups contain invert sugar, 
 varying from a fraction of a per cent up to 25 per cent 
 or more. This fact may be due in part to the presence of 
 the glucoses in the natural juice, 1 or to inversion of some 
 
 1 Many authorities hold that the glucoses of the cane plant are not present 
 as constituents of invert sugar, as apparently they are optically inactive. This 
 point has been touched upon in the previous chapter, as well as the possible 
 bearing of the action of basic lead acetate on the rotation of invert sugar. 
 
104 DOUBLE POLARIZATION 
 
 sucrose during the handling of the cane or the manufactur- 
 ing of the sugar. 
 
 Evidently, every equivalent of invert sugar by its left- 
 rotatory effect neutralizes the right-rotatory effect of about 
 one third of the same equivalent of sucrose, and the sac- 
 charimeter underreads the true sugar per cent by that 
 amount. 
 
 Often in commercial table sirups r^/-rotating sub- 
 stances are present, as in mixtures of "commercial glu- 
 cose," which has a specific rotation of 130 or more. 
 
 Clerget Method of Double Polarization. Clerget, in 1849, 
 first devised a practical working method l for the estimation 
 of cane sugar in the presence of other optically active 
 substances. The method depends on the following prin- 
 ciples : (i) Cane sugar, alone of the optically active sub- 
 stances with which it is ordinarily associated in commercial 
 products, undergoes a change affecting its rotatory power 
 when hydrolized with hydrochloric acid, provided that 
 this treatment is carried out under the strictly limiting 
 conditions defined by the process. This change is due 
 to a complete inversion of the cane sugar. (2) A definite 
 weight of cane sugar has its rotation changed by inversion 
 by a constant number of divisions of the saccharimeter at 
 any definite temperature. (3) Hence the amount of change 
 in rotation by inversion of a definite weight of any sample 
 is proportional to the cane sugar it contains, and bears a 
 constant ratio to the amount of change in rotation occur- 
 ring under similar conditions in the same weight of pure 
 sugar. This ratio, therefore, expresses the percentage of 
 sugar in the sample. (4) As the specific rotation of the 
 
 1 Ann. Ckim. Pkys. 26 (3), 185. 
 
DOUBLE POLARIZATION 1 05 
 
 levulose formed by the inversion decreases by increase of 
 temperature, the temperature influence must be considered 
 
 (in the calculation. (5) As the amount of change in rota- 
 "*tion. (the algebraic difference between the polariscope 
 readings before and after inversion) alone is the measure 
 ' of the cane sugar present, and since cane sugar alone is 
 changed by the process, the rotatory effects of the other 
 optically active substances have no influence on the results. 
 The difference between the two readings and not their 
 magnitudes is the measure. 
 
 The normal weight of pure cane sugar reading 100 on 
 the saccharimeter, when inverted by hydrochloric acid 
 under the conditions denned by Clerget, reads 34 at 
 20. The total change in the reading is, therefore, 134 
 divisions. At o the difference is 144, and at any temper- 
 ature t can be expressed as 144 If then the normal 
 
 2 
 
 weight of sample, polarized under standard commercial 
 conditions, gives a reading of a on the saccharimeter, and 
 a reading b, when inverted and polarized by Clerget's 
 method, the per cent of sugar in the sample will be 
 
 i 44 -^ 
 
 ( If any weight of sample other than the normal is used, 
 
 N 
 multiply by 
 
 What is practically the original method is as follows : 
 Prepare and polarize the sample by the standard com- 
 mercial method, but using the half-normal weight if the 
 sample is highly colored. Save the filtrate, prepared for 
 
IO6 DOUBLE POLARIZATION 
 
 the direct polarization, for inversion. Take 50 cubic 
 centimeters of this nitrate in a 50-5 5 -cubic-centimeter 
 double marked flask, and add hydrochloric acid of a 
 density of 1.20 to the 55 mark. Mix, and heat gradually 
 to 68, taking fifteen minutes to reach this temperature. 
 Then cool at once under running water to room tempera- 
 ture. Allow any precipitate of lead chloride to settle out, 
 and polarize in a 2.2-decimeter tube provided with a ther- 
 mometer, 1 which is read to 0.1 when the solution is 
 polarized. If the ordinary 2-decimeter tube is used, the 
 saccharimeter reading must be increased by 10 per cent, 
 since it has been necessary to increase the volume by that 
 amount, in order to add the necessary amount of acid. 
 A water bath is the usual method of heating the flask, but 
 a double-walled oven heated by boiling xylol, which gives 
 an interior temperature of about 120, will heat the solution 
 to 68 in, very closely, the right time interval. A water- 
 jacketed oven is too slow, requiring a preliminary heating 
 of the flask to about 45 in a flame. 
 
 If the time interval is too short, inversion is not com- 
 plete, and if the heating is prolonged, or the temperature 
 of 68 exceeded, some levulose is decomposed. The 
 conditions of the inversion must be strictly adhered to. 
 (Note that zero errors of minus readings have corrections 
 in the opposite sign to those of plus readings.) 
 
 The Clerget method is valuable in many investigations, 
 but, obviously, judgment must be used in its application, 
 for it is clear that such a strong hydrolytic agent as 
 hydrochloric acid will in many cases act upon the rotatory 
 substances present. When " commercial glucose " is 
 
 1 See Fig. 23, p. 93 ; also footnote, p. 90. 
 
DOUBLE POLARIZATION 
 
 107 
 
 present in large amount, an error amounting to some 
 tenths of a per cent is introduced, owing to the slight 
 hydrolysis of this substance during inversion of the cane 
 sugar. 1 Many prefer the modified German method of 
 Herzfeld, 2 which is somewhat more complicated, but uses a 
 more dilute acid solution, and is more accurate in samples 
 of low sugar content, as it takes into consideration the 
 change in factor caused by the change in the specific 
 rotation of levulose due to dilution. The German method 
 takes the half-normal weight of sample, which is dissolved 
 in 75 cubic centimeters of water in a loo-cubic-centimeter 
 flask, $ cubic centimeters of hydrochloric acid of a density 
 of 1. 1 9. added, and the volume made up to the mark, and 
 heated on a water bath to 67-70, and then kept at that 
 temperature for 5 minutes, the whole heating taking from 
 7^ to 10 minutes. The factor of change in rotation varies 
 with the concentration, being given in the following table : 
 
 GRAMS 
 
 
 GRAMS 
 
 
 GRAMS 
 
 
 GRAMS 
 
 
 SUGAR IN 
 
 
 SUGAR IN 
 
 
 SUGAR IN 
 
 
 SUGAR IN 
 
 
 100 CUBIC 
 
 FACTOR 
 
 TOO CUBIC 
 
 FACTOR 
 
 100 CUBIC 
 
 FACTOR 
 
 loo CUBIC 
 
 FACTOR 
 
 CENTI- 
 
 
 CENTI- 
 
 
 CENTI- 
 
 
 CENTI- 
 
 
 METERS 
 
 
 METERS 
 
 
 METERS 
 
 
 METERS 
 
 
 I 
 
 141.85 
 
 6 
 
 142.18 
 
 II 
 
 142.52 
 
 16 
 
 142.86 
 
 2 
 
 141.91 
 
 7 
 
 142.25 
 
 12 
 
 142.59 
 
 17 
 
 142.93 
 
 3 
 
 141.98 
 
 8 
 
 142.32 
 
 13 
 
 142.66 
 
 18 
 
 143.00 
 
 4 
 
 142.05 
 
 9 
 
 142.39 
 
 '4 
 
 H2.73 
 
 19 
 
 143.07 
 
 5 
 
 142.12 
 
 10 
 
 142.46 
 
 15 
 
 142.79 
 
 20 
 
 H3-I3 
 
 As the half -normal weight is used, the results are 
 multipled by 2. 
 
 1 Weber and McPherson, /. Am. Chem. Soc., 17, 319. 
 
 2 Zeit. Ver. deut. nib. zuck. Ind., 38, 699. 
 
IO8 DOUBLE POLARIZATION 
 
 Many modifications of the Clerget method have been 
 suggested with the object of diminishing the possible de- 
 structive influence of the acid on the carbohydrates other 
 than sugar. Citric acid has been used as a hydrolyte, and 
 seems especially fitted for investigations of honeys. The 
 destructive action of the acid can be greatly mitigated by 
 carrying out the inversion at ordinary room temperature. 
 The inversion is said to be complete if the Clerget solution 
 is allowed to stand for about eighteen hours at a tempera- 
 ture of about 20. These modifications, however, have not 
 yet been developed into standard methods. 1 
 
 Determination of Sucrose and Raffinose. In beet molasses 
 and low-grade beet sugars, invert sugar is practically ab- 
 sent, but an optically active substance known as raffinose, 
 of marked melassagenic action, is often present to the 
 extent of several per cent. This is a trios e sugar, being an 
 anhydride combination of three glucose sugars, dextrose, 
 galactose, and levulose. Its specific rotation is 104.5. By 
 hydrolysis with acid, when the hydrolytic action is mild, 
 raffinose changes so that its rotation becomes about half 
 
 1 Tolman (y. Am. Chem. Soc., 24, 515) states that hydrochloric acid used 
 in inverting solutions already containing invert sugar, as honeys and jams, 
 increases the levorotation. Tolman gives a graphical correction method for 
 eliminating this error, and also states that the variation in the Clerget factor 
 found by Herzfeld is due to this effect of the acid on the rotation and not to 
 differences in sugar concentration. It follows from this that, if this influence 
 is done away with, the Clerget equation becomes, for all conditions of sugar 
 concentration at any given temperature, 
 
 ~ _ a b 
 
 141.85 p.5 / 
 
 and that the invert sugar per cent of solutions containing only sucrose and 
 invert sugar is given by the equation : 
 
 - 41.85 + . 5 / 
 
DOUBLE POLARIZATION IOQ 
 
 as great. By more energetic hydrolysis, the rotation 
 changes to one fifth the value.' The first stage of the 
 inversion is the formation of levulose and a biose sugar 
 known as melibiose. By further hydrolysis, the latter is 
 broken up into galactose and dextrose. Creydt has calcu- 
 lated formulae for adapting the Clerget method to the 
 estimation of sucrose and raffinose in beet-sugar products. 
 The readings are taken at 20, the inversion being carried 
 out according to the German modification of Clerget's pro- 
 cess. The formulae are based on the fact that the change 
 in rotation of a sucrose solution of normal concentration, 
 by inversion, is from 100 to 32.66 at 20 C., while the 
 normal solution of raffinose changes from 185.2 to 94.9 
 saccharimetric divisions under the same conditions. 
 The equations are as follows : 
 
 for sucrose, s = 
 
 for raffinose. R = 
 
 .8390 
 
 > 
 
 1.852 
 
 a being the direct reading; b being the reading after in- 
 version, of the normal weight of sample. 5 and R are the 
 per cents of sucrose and raffinose respectively. 
 The equations are derived as follows : 
 
 tf=S+ 1.852^; (i) 
 
 b = .3266 5 + .949 R. (2) 
 
 Multiplying (i) by -949 ( = .5124), and subtracting (2) 
 1.852 
 
 from it gives .5124*2 b = .8390 5. 
 
 The method of Creydt has been modified in a number of 
 ways, more particularly with the object of obtaining better 
 
HO DOUBLE POLARIZATION 
 
 clarification, as the principal difficulty is with the darken- 
 ing of the inverted solutions. The use of zinc dust in the 
 inverted solution as a bleaching agent has proved advan- 
 tageous, and is the feature of several of these modified 
 processes. 1 
 
 Speaking in general of double polarization methods, 
 none of them are of universal application ; but, if the prin- 
 ciples involved are thoroughly understood, they can be 
 applied to great advantage when modified by the intelligent 
 chemist to suit the requirements of the analysis. 
 
 1 See: Lindet, Sug. Cane, 1889, 542; Courtonne,/. des fab. de Sue., 1890; 
 Herzfeld, Zeit. d. V. f. Riibenzucker-Ind., 1890, 165; Davoll, /. Am. Chem. 
 Soc., 1903, 1019; Fruhling, Anleit. z. Untersuchung der Rohmaterialen (etc.) 
 fur die Zucker Industrie, 6th ed., p. 92. 
 
SUGARHOUSE AND REFINERY METHODS 
 
 IT is not intended to discuss in detail either laboratory 
 methods or processes of sugar manufacture, as there 
 are many excellent treatises exclusively devoted to these 
 matters. The subject will be dealt with very generally, 
 to illustrate the nature of the work required of the sugar 
 chemist, who often is made responsible for the manage- 
 ment of the factory work itself. He should seek to master 
 thoroughly the chemical and engineering principles on 
 which the work is based, rather than simply learn details 
 of special methods and processes. Local conditions of 
 one sugarhouse often require radical changes, and the 
 development of a scheme of work differing materially 
 from that in practice elsewhere. In this chapter, certain 
 basic methods only will be enlarged upon, and a scheme of 
 chemical control of a cane-sugar house given as merely 
 suggestive of how such work is done. 
 
 In the manufacture of sugar from the cane, as a finished 
 product for the consumer, the work is divided between 
 the factories at the plantation, which make a crude prod- 
 uct, and the refineries, that purify, decolorize, and recrys- 
 tallize this "raw sugar." In the United States, practically 
 all the sugar from the cane reaches the consumer through 
 the refinery. Beet sugar, to a large extent, is made and 
 refined in the same factory, although large quantities of 
 raw beet sugars are made in Europe specially for export. 
 
 in 
 
112 SUGARHOUSE AND REFINERY METHODS 
 
 Considering first the manufacture of sugar from cane, 
 this can be divided as follows : (i) cultivating and harvest- 
 ing of the plant, and the transportation of the canes to the 
 factory; (2) extraction of the juice in which the sugar is 
 dissolved from the plant tissues; (3) clarification of the 
 juice from colloidal impurities, especially those which in- 
 terfere with the evaporation of the juice and consequent 
 crystallization of the sugar; (4) evaporation of the clari- 
 fied juice to an appropriate density favorable for most 
 effective crystallizing out of the sugar; (5) crystallization 
 processes; (6) separation of the sugar crystals from the 
 mother liquor, known as " molasses" ; (7) treatment of the 
 molasses by more or less modified but similar process for 
 the extraction of more sugar, but of lower purity, known as 
 "molasses sugar." 
 
 (i) Chemistry has only been applied to a limited extent 
 in cane culture. Although there are the beginnings of 
 much excellent work on fertilizing and soil analysis, espe- 
 cially in Hawaii and Louisiana (one very successful house 
 in Hawaii spending more than $100,000 in scientifically 
 prepared fertilizers), work on this line is not usually under- 
 taken by the factory chemist, and need not be considered 
 in a treatise on sugar methods. Agricultural chemistry 
 promises to play an important part in the cane-sugar 
 _ndustry of the future. 1 
 
 1 For many centuries sugar cane has been cultivated by propagation from 
 cuttings, and in consequence the plants are sterile as a rule. It is only in 
 recent years, in Java, that seedlings have been successfully cultivated. These 
 have been obtained from plants which have been induced to bear seed by 
 transplanting to the higher mountain levels, where conditions for growth were 
 unfavorable. Seedling farms have now been established in Louisiana, Barba- 
 does, Cuba, and other cane countries, and are showing much promise for the 
 economic improvement of the cane on the lines so successful in beet culture. 
 
SUGARHOUSE AND REFINERY METHODS 113 
 
 Valuation of the Cane. Unlike the beet, sugar cane 
 cannot properly be valued by analyses made on laboratory 
 samples, owing to the practically insuperable difficulty of 
 obtaining any small lot of cane which is representative. 
 Different individual canes vary so much that analyses of 
 one or two are of little value. The only satisfactory valua- 
 tion of the cane is determined by the quality of the juice 
 sampled from the mills themselves during the grinding of 
 a lot of several tons. If, however, a sample of at least a 
 dozen canes is carefully selected so as to represent the 
 actual lot as fairly as can be observed, and the juice from 
 these canes is extracted by a laboratory three-roller mill, 
 such as are now specially made for the purpose, the mill 
 being adjusted and the crushing made so as to give an 
 extraction approximating that in actual practice in the fac- 
 tory, the analyses will .agree very well with those of the 
 mill juice from the sugarhouse. This will require running 
 the sample canes three or more times through the experi- 
 mental mill. Such preliminary laboratory tests are impor- 
 tant in many cases, as where it is necessary to examine the 
 standing cane from the fields to ascertain its fitness for 
 grinding, for instance ; but in factory control the test of 
 the juice actually obtained in the sugarhouse is a better 
 valuation, and the one usually relied on. 
 
 The cane coming to the mill is weighed in the carts or 
 cars in which it is brought. To this weight all yields and 
 losses are usually referred as percentages, although a better 
 basis of leference is the weight of sugar in the juice actu- 
 ally extracted or the calculated weight of sugar in the cane. 
 This latter weight, however, is somewhat approximate, as 
 it is practically impossible to obtain directly an accurate 
 
SUGARHOUSE AND REFINERY METHODS 
 
 determination of the fibre in the cane, which is a necessary 
 datum for this calculation, owing to the difficulty already 
 alluded to of obtaining a representative laboratory sample. 
 It should be explained here that, for convenience in calcu- 
 lation, the cane is arbitrarily divided into two parts, juice 
 m\& fibre: the juice being that part which can be extracted 
 by exhaustive treatment with water ; the fibre, the residue 
 after drying, in ripe tropical canes about 1 1 per cent. 
 It consists of pentosan bodies and other insoluble matter ' 
 besides the cellulose, which is its chief constituent. 
 
 (2) The Juice Extraction. In the best modern houses, 
 the cane passes through three mills 1 of three rollers each, 
 so that it actually undergoes six crushings. Sometimes the 
 
 three mills are com- 
 JJ U ^s~\ .. ,. 
 
 bined in one machine. 
 
 The crushed mass 
 coming from the mill 
 is called " bagasse," 
 and should be a fri- 
 able mass of fibre 
 barely moist to the 
 touch, although actu- 
 ally containing about 
 50 per cent of mois- 
 ture. The bagasse 
 goes to the boiler furnaces as fuel, and with it, of course, 
 a certain amount of sugar in the juice not completely 
 extracted. This is the first inevitable loss in manufacture. 
 
 1 Extraction by diffusion is not discussed here, as in most cane-growing 
 countries this method of juice extraction is impracticable, owing to local con- 
 ditions. Sometimes the cane is passed through a " crusher " or " shredder," 
 to more thoroughly disintegrate it before milling. 
 
 FIG. 25. SECTION OF CANE MILL. 
 
 (From Thorp's " Outlines of Industrial Chemistry.") 
 
SUGARHOUSE AND REFINERY METHODS 115 
 
 The juice from the mills is either weighed directly by 
 automatic weighing machines, or its weight determined, as 
 is usual, by calculation from its density, obtained by the 
 " Brix spindle" (shortly to be described), and its volume, 
 measured in calibrated tanks, usually the clarifiers. The 
 weigJit of j nice as a percentage of tJie weight of cane ground 
 is known as the " extraction " of the mills. 
 
 Ripe cane is treated with hot water, which is commonly 
 applied to the bagasse sheet passing between the second 
 and third mills. This is known as " maceration," and con- 
 siderably increases the extraction. The amount of water 
 added varies, according to circumstances, from 5 to 20 per 
 cent, or more, of the weight of the juice, and necessarily com- 
 plicates the extraction calculation, as will be explained later. 
 
 The extraction of a modern sugarhouse varies from 72 
 to 80 per cent, or more, according to quality of the cane and 
 manner of milling. Often the third mill juice, which only 
 amounts to a few per cent of the total, is treated separately, 
 owing to its greater impurity ; and in some factories lime 
 is added to the bagasse in maceration. These and other 
 modifications of process require corresponding modifica- 
 tions in the chemical control, which must be made by the 
 chemist to suit the peculiar conditions. 
 
 The juice coming from the mills is a thin, opaque sirup, 
 usually of a dark olive color, the tint varying considerably 
 according to the condition of the cane and the soil on 
 which it is grown. Beside 1 5 to 20 per cent of sucrose, it 
 contains about .4 per cent of albuminoids, waxy matter, 
 and other plant extractives. Small quantities of glucose 
 sugars are also present, in ripe cane less than .3 per cent> 
 and an insignificant amount of mineral matter. 
 
Il6 SUGARHOUSE AND REFINERY METHODS 
 
 The determinations on the juice important for factory 
 control are the sugar per cent and the "quotient of 
 purity." 
 
 Quotient of Purity. As, in the different steps of sugar 
 manufacture, the zvater content of the product in process is 
 constantly changing, a simple polarization giving the per 
 cent of sugar on the weight of sample is of little value as 
 a measure of the purity of the product, unless made on the 
 water-free (anhydrous) substance. In the necessarily rapid 
 determinations of factory control it is impracticable to dry 
 each sample before polarizing. If, however, the/^r cent of 
 total solids in the sample can be conveniently obtained, the 
 percentage ratio of the sugar per cent of the sample to this 
 value will be the per cent of sugar in the anhydrous sub- 
 stance. As this ratio is independent of the water content, 
 the determinations of total solids and sugar percentages 
 can be made on solutions of the sample at any convenient 
 concentration, the only condition being that both tests are 
 referred to the same concentration. 
 
 This ratio, giving the per cent of sugar in the anhy- 
 drous substance of the sample, is known as its " quotient 
 of purity" (" purity "), and can be expressed in the equation : 
 
 T OO "P 
 
 Q = , where P is the polarization of the solution of 
 ^ 
 
 the product at any convenient concentration, and 5 is the 
 per cent of total solids at the same concentration. 
 
 Determination of Total Solids. The density of the solu- 
 tion gives a rapid means of determining the per cent of 
 total solids with an approximation sufficiently close for the 
 purpose, the assumption being made that the impurities 
 (" non-sugars ") in the juice affect the density in the same 
 
SUGARHOUSE AND REFINERY METHODS 1 1/ 
 
 proportion as would an equivalent weight of dissolved 
 sugar. 
 
 Hydrometers of great precision are specially made for 
 sugar testing, which are graduated to give at a standard 
 temperature (17.5 C.) a direct reading of the per cent of 
 :ugar in a pure solution. In solutions of the impure pred- 
 icts of cane-sugar manufacture, such a hydrometer gives 
 eadings expressing the per cent of total solids very closely. 
 
 These hydrometers are known as " Brix spindles " or, 
 sometimes, " Balling spindles." Balling was the first to 
 calculate the tables on which their graduation depends. 
 Brix revised them later, his values being practically iden- 
 tical with those of Balling, except at the higher con- 
 centrations. The better class -of Brix spindles have a 
 thermometer attached, and often this thermometer is 
 graduated to give by direct reading the correction for 
 the Brix reading at any temperature other than at 17.5. 
 These thermometer graduations for the Brix temperature 
 corrections are usually inexact, because the makers com- 
 monly make the assumption that the coefficient of 
 expansion of the solution is the same as that of pure 
 water, whereas it is perceptibly greater, even at moderate 
 concentrations. If such graduations are placed on the 
 thermometer, it should only be done on spindles having a 
 range of scale of 10 or less, and the corrections should 
 be calculated for a concentration corresponding to the 
 middle reading of the scale of the spindle. 
 
 Table No. 2 (see Appendix) should be used for making 
 these corrections in accurate work. 
 
 Reading of Brix Spindles. Brix spindles, like all cor- 
 rectly made hydrometers, should be read along a line lying 
 
n8 
 
 SUGARHOUSE AND REFINERY METHODS 
 
 in the plane of the surface of the liquid (shown by line a, 
 Figure 26), and not at the line of contact of the liquid with 
 the stem (), this line being raised above the surface by the 
 capillary attraction of the liquid, to a varying extent de- 
 pending on the viscosity of the 
 liquid. Some of the Brix spin- 
 dles made for commercial work 
 are graduated for 15 C. or 
 60 F. Some sugar refiners 
 use the Fahrenheit scale on 
 their Brix spindles, the stand- 
 ard being practically the same 
 
 asi 7 .5C.(63.5 )- 
 
 Determination of Sugar in 
 Solutions. Owing to the in- 
 convenience and inaccuracy 
 of determining weights of 
 liquids by a balance, methods 
 have been devised for polar- 
 izing sugar solutions without 
 the necessity of weighing. 
 One way is by use of the 
 "sucrose pipette," which is a 
 FIG. 26. ILLUSTRATING METHOD pipette of the ordinary shape 
 
 OF READING A HYDROMETER. ^ graduated Qn the upper 
 
 stem with a series of marks corresponding to degrees Brix. 
 If the pipette is filled to the mark corresponding to the 
 reading of the solution given by a Brix spindle at the 
 temperature of observation, it will deliver the normal 
 weight of 26.048 grams of the solution. These pipettes, 
 being used for juice testing, are usually made to deliver 
 
SUGARHOUSE AND REFINERY METHODS 119 
 
 double the normal weight, and so reduce the error of the 
 small saccharimetric readings correspondingly. 
 
 The method of determining the per cent of sugar in a 
 solution, generally used in refinery practice, depends on 
 the following principles : 
 
 As the normal weight of pure sugar, dissolved in 100 
 cubic centimeters of solution, when polarized in a 2-deci- 
 meter tube, gives a saccharimetric reading of 100, then : 
 any saccharimetric reading (R) of any solution containing 
 sugar (sucrose) as the only optically active substance, and 
 
 r> 
 
 polarized in a 2-decimeter tube, shows that - - of the nor- 
 
 i oo 
 
 mal weight of sugar must be dissolved in 100 cubic centi- 
 meters of the solution. If this value is divided by the 
 density of the solution, 1 the quotient will give the per cent 
 of sugar in the solution. 
 
 Hence, expressing the normal weight by N, and the 
 density by d, the sugar per cent of any solution (S\ when 
 its saccharimeter reading given by a tube of standard 
 length (2-decimeter) is known, can be found by the follow- 
 
 RN 
 
 ing equation : 5 = . 
 100 rf 
 
 In practical work, as most solutions to which this method 
 is applied, such as cane juices and molasses, have to be 
 clarified before they can be polarized, it is necessary in 
 such cases to allow for the change in concentration of the 
 solution resulting from the addition of the clarifying agent. 
 This is most conveniently done by the double-marked flask, 
 such as has been described under the Clerget method of 
 double polarization. The flasks customarily used are 
 graduated at 100 and no cubic centimeters, although as 
 
 1 See the equations expressing concentration of solutions on pp. 12 and 13. 
 
120 SUGARHOUSE AND REFINERY METHODS 
 
 the function of the flask is to determine the ratio of dilu 
 tion, it is immaterial whether this size or the 50-55 flask is 
 used, the errors of observation of the reading of the 
 smaller volume, being well within the other errors of 
 analysis. In such cases, obviously, the equation given 
 must be multiplied by j^. Tables allowing for the 
 increase of -^ in the original concentration, and based 
 on the equation given above, have been designed by 
 Schmitz for the use of sugar chemists. 1 These tables 
 give the per cent of sugar directly when the saccharimetric 
 and Brix readings are known, the Brix reading in this case 
 being used as an expression of the density in the calcula- 
 tions. The calculations of the table are corrected for 
 slight changes in the specific rotation of sucrose at low 
 concentrations in very dilute solutions. This affects the 
 third significant figure, hence the table differs from the 
 results obtained by the equation only by that amount. 
 
 Method of Determination of Quotient of Purity. The 
 ordinary method of quotient of purity determination is as 
 follows : If the sample is a cane juice, strain out any par- 
 ticles of bagasse by passing the juice through fine copper 
 gauze, and allow it to stand till all the air bubbles have 
 escaped. The Brix reading is then taken. If the sample 
 is a molasses or similar product, it is diluted to about 15 
 Brix before taking the exact Brix reading. 2 All Brix read- 
 ings must be corrected, of course, to standard temperature. 
 
 The Brix reading expresses the per cent of total solids 
 in the solution, and from the same reading the density can 
 
 be determined by a comparison table (see Table No. i in 
 
 
 
 1 See Table No. 3 in Appendix. 
 
 2 See Hartmann, Hawaiian Planter? Monthly ', 22 (1903), 383. 
 
SUGARHOUSE AND REFINERY METHODS 121 
 
 Appendix). A double-marked flask is now filled to the 
 lower mark with the solution, the requisite amount of basic 
 lead acetate added to clarify, and the solution made up to 
 the upper mark and thoroughly shaken. The solution is 
 then filtered and polarized in the ordinary manner. 
 
 The refiners use their own " exponent " books, which are 
 arranged in tables to give the quotient (" exponent") with- 
 out calculation for known Brix and saccharimeter readings, 
 the sugar per cents of the liquors in process being usually 
 unnecessary for their records. 
 
 Weisberg's Method of determining Total Solids. 1 Another 
 ingenious method of determining the total solids without 
 the use of the Brix spindle, only applicable to molasses 
 and other concentrated products denser than 78 Brix, has 
 been devised by Weisberg, and is in practical use in some 
 European houses. It is based on the fact that, accord- 
 ing to the original Ventzke standard, by which the sac- 
 charimeter is graduated, a solution of the normal weight 
 (26.048 grams) of pure sugar dissolved in 100 Mohr cubic 
 centimeters has a density of i.ioco at 17.5 C. referred to 
 water at 17.5 as unity. As in the Brix method, it also 
 makes the assumption that the non-sugars have the same 
 density factors as the dissolved sugar. 
 
 If 26.048 grams of the sample are dissolved in 100 cubic 
 centimeters of solution, the significant figures of the den- 
 sity value, less i.oooo, will express the per cent of total 
 solids in the sample. For instance, if the density is 1.0846, 
 the original sample contains 84.6 per cent solids. The sac- 
 charimeter reading, of course, gives the per cent of sugar 
 
 1 For other methods of determining quotient of purity, see Wiechmann, 
 " Sugar Analysis." 
 
122 SUGARHOUSE AND REFINERY METHODS 
 
 in the sample, as the solution is a normal one for the 
 saccharimeter. 
 
 Quotient of purity determinations are of great value to 
 the manufacturer as giving rapid comparative figures for 
 determining the efficiency of the different processes. To 
 the refiner, particularly, they are indispensable as a basis 
 for planning the most economical working of raw material, 
 often of the most variable quality, into a uniform refined 
 product. Too much importance, however, should not be 
 attached to exact numerical value expressed by the purity 
 figures, as, owing to the diverse nature of the " non-sugars " 
 under different circumstances, products of the same 
 " purity " may work up quite differently. 
 
 Other tests made on cane juice, of more or less value 
 for chemical control of the factory, are for acidity and 
 glucose sugars. Acidity tests are usually expressed in 
 terms of decinormal sodium hydrate or lime to neutral- 
 ize, using phenolphthalein as an indicator. The glucose 
 test is not considered so important as formerly, when 
 these sugars were supposed to have a much greater effect 
 than they do have upon the crystallization of the sucrose. 
 As a matter of fact, the glucose sugars in themselves have 
 little harmful effect, but their amount in juice from fresh 
 cane is to a large extent indicative of its condition. Un- 
 ripe cane always contains a larger proportion of glucose, 
 which is associated with albuminoid (pectenoid?) sub- 
 stances, usually termed " gum." These greatly increase 
 the viscosity of the liquors in process, retarding evapora- 
 tion and interfering with crystallization. They are only 
 partially removed by the ordinary processes of clarifica- 
 tion. The glucoses are the indicator rather than the dis- 
 
SUGARHOUSE AND REFINERY METHODS 123 
 
 turbing cause, and as one test for unripe cane this deter- 
 mination has some value. 1 As any destruction of sucrose 
 by inversion due to ferments or other cause produces glu- 
 cose sugars, any marked increase in the "glucose ratio" 
 (the ratio of glucose to sucrose) in the products in process 
 is evidence of inversion; but as, in the majority of cases, 
 these glucose sugars are destroyed to considerable extent 
 during the processes of clarification and in the "meladuras" 
 (evaporated sirups), the values of the glucose ratio must 
 be interpreted with considerable caution. The methods 
 of determining glucose sugars will be discussed later. 
 
 Determination of Extraction when the Juice is diluted 
 by Maceration. When the juice is diluted by maceration 
 water, the determination of the amount extracted at its 
 original concentration is somewhat complicated. In this 
 case it is necessary to determine the Brix of the juice from 
 the mill before it is macerated, and also the Brix of a 
 sample of the total amount of completely mixed and 
 diluted juice. The per cent of maceration water will be 
 
 Z> T) 
 
 given by the following equation : P = ^ ^ wnere p 
 
 &\ 
 is the per cent of maceration water in the juice, B l is the 
 
 Brix of the normal juice, B% the Brix of the diluted juice. 
 From these data the weight of the normal juice can be 
 readily obtained. 2 
 
 1 Ripe cane, if old and soured, of course, contains glucoses from the inver- 
 sion. Such cane, if not absolutely rotten, "works" easily, as the "gum" is 
 absent, although it gives a poor yield and much molasses. 
 
 2 The quality of the juice from the different mills varies somewhat, that 
 from the later crushings having more impurities. Maceration also lowers the 
 purity of the juice. This small change in quality of the juice does not appre- 
 ciably affect the calculation given here. 
 
124 SUGARHOUSE AND REFINERY METHODS 
 
 Determinations on the Bagasse. The per cent of sugar 
 in the bagasse is sometimes determined as a check on the 
 extraction figures, but the most useful datum is the fibre 
 content, as this can be utilized to estimate the fibre in the 
 cane by calculation from the extraction. The extraction 
 being known, the per cent of fibre in the bagasse can be 
 referred to the cane itself. The great difficulty in this 
 determination is in the sampling, as not only does the 
 bagasse vary in its nature, but it dries very rapidly in a 
 small sample. The only proper sample is one of at least 
 200 grams. The bagasse should be collected in a covered 
 box, in which it should be weighed without removal to 
 avoid error from evaporation. The weighed sample, if 
 not well shredded, should be picked to pieces and then 
 placed in a gauze basket and thoroughly washed, prefera- 
 bly in warm soft water, till the washings no longer react for 
 sugar. The residue, dried at 105 C, is taken as the " fibre." 
 
 Juice. The juice should be sampled at least once an 
 hour, the samples either being tested at once or measured 
 portions put in a graduated bottle in which has been 
 placed a few drops of mercuric chloride solution to avoid 
 fermentation. This general sample is tested at regular 
 intervals, three or four times in twenty-four hours. As 
 lots of cane from different plantations are often bought at 
 a price based upon the quality of the juice extracted by the 
 mill, individual samples of juice are also taken from the 
 mills during the grinding of such lots and tested separately. 
 
 Conditions, of course, will considerably modify the chem- 
 ical control methods, and many other interesting and valu- 
 able tests can be made on the juice, such as those which 
 throw light on the nature of the colloidal non-sugars and 
 
SUGARHOUSE AND REFINERY METHODS 125 
 
 their removal, the viscosity of the juices, etc. Such work 
 will depend on the facilities at the disposal of the chemist. 
 (3) The juice from the mills next goes to the clarifiers, 
 either directly or after a previous mixture with the precipi- 
 tant, and in many cases a preliminary heating by the waste 
 heat from other factory processes, which is thus econo- 
 mized. Clarification in raw cane-sugar manufacture is 
 a crude process at best, 1 and is only designed to remove 
 those impurities which have influence in preventing crys- 
 tallization and evaporation. These impurities are in the 
 main of an albuminoid nature, the -composition of which 
 is little understood. They seem to be of an amino or 
 amido constitution, related to glycocoll or asparagine, and 
 xanthin bases. They exist in the juice in a " colloidal" 
 or gelatinous condition, and consequently have to be pre- 
 cipitated before they can be removed by settling or filtra- 
 tion. There is also a waxy substance from the rind of 
 the cane. By bringing the juice to practically the neutral 
 point with fresh quicklime and heating to about 185 F. 
 (85 C.), about 50 per cent of the total albuminoids are 
 precipitated, which is sufficient for raw-sugar manufac- 
 ture. The special clarification or " defecation process," 
 as usually carried out, consists in heating the limed juice 
 in shallow tanks ("defecators") provided with a relatively 
 large heating surface so as to produce rapid enough con- 
 vection to throw the precipitated albuminoids and wax 
 to the surface, where they remain as a thick scum or 
 
 1 A certain amount of white sugar is made in all sugar countries for local 
 consumption. This sugar, as a rule, is made from liquors which have under- 
 gone a second filtration and bleaching with sulphur dioxide, and is carefully 
 washed in the centrifugal machines, steam being used to make dry crystals. 
 
126 SUGARHOUSE AND REFINERY METHODS 
 
 " blanket." After the clarified juice is allowed to stand 
 till the small amount of settlings deposit, the clarified 
 juice, which in an ordinary test tube looked at trans- 
 versely usually appears as a clear yellowish green sirup, 
 is decanted into tanks for further settling before going 
 to the evaporators. The amount of lime required for 
 defecation varies considerably with its quality and the 
 condition of the juice, for fresh ripe cane juice, averaging 
 about 6 pounds per 1000 gallons. It may vary greatly 
 from this figure. The point of proper defecation is prac- 
 tically the neutral point. Usually, but not necessarily, the 
 decanted juice shows a faint alkalinity (.002 to .005 with 
 phenolphthalein). The exact point is much better shown 
 by the appearance of the precipitated albuminoids and the 
 clarified liquor than by any of the usual indicators. Proper 
 defecation is shown by the appearance of a well-defined 
 coagulation, the coagulated matter being flocculent and 
 settling slowly, leaving a practically clear sirup. Over- 
 limed juice is dark colored, and the precipitate settles 
 rapidly. In underlimed juice the liquor is milky from 
 incomplete coagulation. The odors also are characteristic 
 to an expert. Overlimed juices make deposits on the coils 
 of evaporating apparatus, and also produce slimy humus 
 products from the decomposition of the glucose sugars, 
 which interfere in the purging in the centrifugals, espe- 
 cially in second sugars. Overliming is a common error, 
 but the consequences of underliming are more obvious. 
 Often loam or clay from canes which have been beaten 
 down by winds or rains give a turbidity which remains in 
 the decanted juice and is apt to deceive the inexperienced. 
 This does little harm if not excessive, and can in the main 
 
SUGARHOUSE AND REFINERY METHODS I2/ 
 
 be removed at the mills by suitable settling devices in the 
 juice canals. 
 
 In the Denting process the continually passing juice is 
 heated in a sort of digester under low steam pressure, the 
 heat of the clarified juice being economized by being trans- 
 ferred back to the entering cold juice, on the principle 
 of the surface condenser. The coagulated albuminoids, 
 which are said to be more perfectly separated, have a ten- 
 dency to settle, and are, when the process works properly, 
 removed from the bottoms of settling tanks. 
 
 In the older methods of defecation, the scums on the 
 surface of the defecators were swept off into draining 
 boxes. In modern houses, they are passed through filter 
 presses. The proportion of juice which passes through 
 the filter presses varies in different sugarhouses, but when 
 the defecation and decantation are properly carried out, 
 does not exceed 15 per cent, even with poor juices. The 
 scums before passing through the presses are cooked with 
 more lime, as this gives a harder press cake, and the 
 slightly alkaline juices neutralize the acidity which would 
 otherwise result from the enormous cooling and aerating 
 surfaces of the presses with their complicated spaces in 
 which fermentation takes place at times in spite of care. 
 The filter-press liquors are slightly darker in color, more 
 alkaline, and of lower purity than the decanted juice. 
 
 Obviously, the second necessary loss in the house comes 
 from the sugar of the juice left in the press cake, and is 
 determined by polarizing a representative sample of the 
 fresh cake, allowance being made in the weight of sample 
 taken, for the volume occupied in the flask by the insoluble 
 matter in the cake, A few drops of acetic acid are added 
 
128 SUGARHOUSE AND REFINERY METHODS 
 
 by some to break up any possible calcium sucrate which 
 might be formed if the liming is excessive. The normal 
 weight for filter cake, as usually taken, is 25.00 grams, 
 which is most conveniently made up to a volume of 
 200 cubic centimeters, the saccharimeter reading, of 
 course, being multiplied by 2. 
 
 The total weight of cake is taken as it is removed from 
 the presses, or can be approximated with sufficient accuracy, 
 by calculation from the number of presses in use, by multi- 
 plying by the average weight of cake per press determined 
 occasionally. 
 
 Other clarification and filtration processes are in use. 
 Often a secondary filtration is given the- juice after clari- 
 fication, by "mechanical," or "sand filters." If the juice 
 is properly defecated, this secondary filtration is quite 
 unnecessary in raw sugar manufacture. 
 
 The loss of sugar in the filter cake, unwashed, usually 
 lies between .10 per cent and .15 per cent of the weight of 
 cane. 
 
 (4) The clarified juice from the settlers goes to the 
 multiple-effect evaporators, where it is concentrated to 
 about 35 per cent of its volume, making a sirup known as 
 " meladura," which is ready for crystallizing in the vacuum 
 pans. 
 
 The density at which this sirup is concentrated depends 
 on its purity, it being difficult to crystallize in the vacuum 
 pan from impure meladuras when very concentrated. Very 
 pure meladuras can be worked up from a density of 30 
 " Beaume " : (54-3 Brix), but meladuras from unripe juices 
 
 1 There are twenty or more different Beaume scales in existence. The 
 original was made by Beaume by taking water at 12.5 C. as zero, and a 10 
 
SUGARHOUSE AND REFINERY METHODS 1 29 
 
 work much better at considerably lower density. At the 
 same time, it must be understood that evaporation is done 
 far more economically in the multiple-effect apparatus than 
 in the vacuum pan. 
 
 Meladura is usually stored in a series of settling tanks 
 of small capacity, so that they can be frequently emptied 
 and cleaned without interfering with the work of the house. 
 At least once a week every tank should be thoroughly 
 cleaned and whitewashed, the settlings being run off into 
 the first molasses (not into the juice scums). 
 
 In the more primitive processes of sugar manufacture, 
 which are still extant in some places, making what are 
 known as "muscovado" or "open kettle" sugars, the 
 clarification and evaporation to the crystallizing point are 
 carried on in a series of hemispherical kettles built into a 
 brick furnace. The lime is added in the first kettle, where 
 the main defecation occurs, and the juice as it evaporates 
 is ladled from one kettle to the next till the more concen- 
 trated sirup is collected in the last. The scums from the 
 defecation are swept in the opposite direction, and finally 
 from the surface of the liquor in the first kettle into a 
 draining box. 
 
 The tests of the meladura useful for chemical control 
 are, its density, its purity, and its alkalinity. The mela- 
 dura should always react faintly alkaline. If it reacts acid 
 from any cause, milk of lime should be stirred in. 
 
 (5) The crystallization of the sugar from the meladura 
 
 per cent solution of common salt as 10. The scale which is in universal use 
 in the sugar industry is that of Gerlach, and is somewhat modified from the 
 original Beaume. This Beaume spindle is exclusively used by workmen in the 
 sugarhouse. 
 
 K 
 
130 SUGARHOUSE AND REFINERY METHODS 
 
 FIG. 27. INSTALLATION OF VACUUM PAN AND CENTRIFUGALS IN A 
 SUGARHOUSE. 
 
 V. Vacuum pan. M. Mixer. 
 
 C. Centrifugals. P. Vacuum and condenser pumps. 
 
 (From an old drawing.) 
 
SUGARHOUSE AND REFINERY METHODS 131 
 
 by the vacuum pan can be divided into three stages : 
 (A) the evaporation of the meladura to the point of sugar 
 saturation; () the formation of the crystals, or " grain- 
 ing " ; (C) the building up of the crystals to the required size. 
 
 In the first stage, the pan is simply working as an ordi- 
 nary evaporator, the special skill of the pan man being 
 required in one particular, the amount of " charge." This 
 must be so regulated that the meladura, concentrated to 
 the saturation point, will have the requisite volume to allow 
 for the growth of sufficient crystals to just fill the pan full 
 when the sugar is finished. This, obviously, is a matter 
 requiring considerable experience, and is conditioned on 
 the quality of the juice, as well as the size of the crystals 
 required, and the polarization. 
 
 The starting of the crystallization is also a matter re- 
 quiring much skill and experience. As soon as the first 
 " sparks " are visible in the " proof," taken out of the pan 
 at frequent intervals, the temperatures must be carefully 
 regulated, usually by manipulating the condensing appa- 
 ratus. The " drinks " of meladura taken into the pan must 
 be as carefully graduated so as to regulate the amount of 
 the crystals which form, for on this will depend to a large 
 extent the quantity of finished sugar of the required polari- 
 zation, as well as the size of the crystals themselves. If 
 the juice be of poor quality, the meladura used to control 
 the crystallization at this point must be less dense, and the 
 temperature raised, to prevent the "grain" forming too 
 rapidly. After the requisite crystal foundation is estab- 
 lished in the " charge," subsequent additions of meladura 
 must be skillfully made during the rest of the process, so 
 that the crystal growth will proceed regularly and con- 
 
132 SUGARHOUSE AND REFINERY METHODS 
 
 tinuously, with the minimum production of " false " or 
 " second grain." This latter is caused by the separation 
 of sugar in fine floury crystals, independently of the origi- 
 nal foundation grain, and cannot be avoided absolutely, 
 although practically evaded by skillful pan men. The 
 second grain, if the crystals are too large to pass the 
 screens of the centrifugal machines, makes "purging" 
 harder, and reduces the polarization of the sugar, owing to 
 the greater absorption (capillarity) due to the unequally 
 sized grains packing more closely. If the second grain is 
 fine enough to pass the screens, it goes into the molasses, 
 and so reduces the yield of the first sugar. 
 
 Skill engendered of long experience and familiarity with 
 the working of his pan are essential qualifications of a 
 first-class sugar boiler. Such men, in raw-sugar work, com- 
 mand high pay and have much responsibility. An unskill- 
 ful man may cause a loss of hundreds of dollars a week. 
 
 When the sugar is finished, the pan is filled with a stiff 
 pasty mass of crystals and molasses in about the proportion 
 of 65 per cent of sugar to 35 per cent of molasses. This 
 is known as "massecuite." 
 
 (6) The steam being turned off and the vacuum broken, 
 the massecuite is discharged into the " mixer," where it is 
 kept slowly stirred till it has all been passed through the 
 " centrifugal " machines, sieves which revolve at a speed 
 of a thousand revolutions or more per minute, by which the 
 molasses is removed, leaving a moist mass of brown sugar 
 crystals. The sugar after being cooled by fans is put into 
 bags usually holding about 300 pounds. 1 
 
 In the chemical control, purity and density tests of the 
 
 1 Hawaiian practice : 125 pounds. 
 
SUGARHOUSE AND REFINERY METHODS 
 
 133 
 
 first massecuite are useful, but are not often made part of 
 the daily routine. 
 
 The polarization of each "strike" of first sugar, as well 
 as the weight obtained, is important. Often it is necessary 
 to follow the working of [ ^^ 
 
 the centrifugal machines 
 during the running, to 
 regulate the time neces- 
 sary for purging, and 
 the amount of " charge " 
 to turn out the requisite 
 quality of sugar. This 
 is done by making polar- 
 izations of samples at 
 once as soon as the purg- 
 ing begins. 
 
 The usual conditions 
 require the sugar to 
 be turned out as near 
 96 per cent as possible. 
 Sometimes the sugar is 
 allowed to stand for some 
 hours in "coolers," or 
 wagons, before purging. 
 This is not commonly 
 done. 
 
 /->. ., , (From Thorp's " Outlines of Industrial Chemistry.") 
 
 One possible source 
 
 of loss in vacuum apparatus is from what is known as 
 "entrapment," which is the carrying off of sirup me- 
 chanically in the current of vapors passing away from 
 the apparatus. The sirup, owing to its viscosity, 
 
 FIG. 28. SECTION OF WESTON CENTRIF- 
 UGAL MACHINE. 
 
 A. Sieve in side of revolving "basket" which re- 
 
 tains the sugar. 
 
 B. Shaft of basket on which slides bell which closes 
 
 opening for discharging sugar. 
 
 C. Casing in which collects the molasses discharged 
 
 through the sieves. 
 
134 SUGARHOUSE AND REFINERY METHODS 
 
 escapes, it is said, in vesicles analogous to minute soap 
 bubbles. 
 
 Modern apparatus is so well designed that entrainment 
 is reduced to a minimum which is practically negligible in 
 good work. Occasionally, steam coils in the pan may 
 spring a leak. If the leak is a small one, it may not affect 
 he working of the pan, but when such coils are shut off, 
 the vacuum formed in the coils causes sirup to enter them. 
 As the condensation water from the coils is used for boiler 
 feed, the sugar may do much damage by collecting in the 
 boilers and causing them to foam. The " tailpipes " of all 
 vacuum-pan coils should be provided with test cocks so 
 that the "returns" can be frequently examined for sugar. 
 The polariscope is hardly sensitive enough to show the 
 small quantity of sugar which it is necessary to detect in 
 some cases, chemical methods being more applicable. 
 Indeed, the color and odor of the returns is sufficiently 
 conclusive of a leak. The returns from the steam cham- 
 bers of the multiple-effect evaporators are also used for 
 boiler feed, so that any entrainment other than from the 
 last effect will also affect the " sweet waters " (as they are 
 erroneously called), and do mischief to the boilers. 
 
 The Brix, polarization, and quotient of purity are taken 
 of a representative sample of first molasses from every 
 " strike " of sugar. 1 
 
 (7) The methods for further extraction of the 50 per cent 
 or more of sugar contained in the molasses vary much in 
 
 1 The most accurate way of determining the total solids (" Brix ") of a 
 molasses is to dilute by weight. For instance, add to 100 grams of the sample 
 sufficient water to make the solution weigh 500 grams. Five times the Brix 
 reading of the solution will give the total solids in the molasses in this case. 
 
SUGARHOUSE AND REFINERY METHODS 135 
 
 different places. Usually, the molasses is diluted some- 
 what, heated to dissolve any <( grain" that may be present, 
 and is concentrated in the pan to the graining point, but 
 not far enough to have crystallization actually take place. 
 It is then run into tank wagons, or into crystallizers, where 
 it is allowed to remain till crystallization is complete, the 
 time being generally from five days to a week. This is 
 known as " boiling blank." The massecuite is then purged 
 in centrifugals, giving " second sugar." Usually the heat 
 is regulated by steam pipes in the " hot room " where the 
 wagons are stored, so as to retard the cooling and allow 
 a gradual growth of the crystals. 
 
 The " crystallizer " is a modern apparatus for controlling 
 the conditions of crystallization more effectively, requiring 
 less skill in handling to obtain a uniform product than the 
 wagon methods. In its ordinary form, the crystallizer is a 
 large horizontal cylinder, holding twenty-five tons or more, 
 provided with a slowly moving stirring apparatus, and 
 arrangements for heating or cooling the contents. The 
 massecuite is run into the crystallizer, where it is allowed 
 to stand for a number of hours, till the crystals have begun 
 to appear, and then the mass is occasionally (very slowly) 
 stirred to bring fresh molasses in contact with the crystals. 
 The temperature is regulated accordingly as the crystal- 
 lization progresses, being also conditioned on local circum- 
 stances. Sometimes, with rich molasses, the graining is 
 made in the pan as in the case of first sugar, or the grain 
 is started with meladura, or sugar is actually put in the 
 pan for a grain foundation. 
 
 Other methods are designed to utilize the first molasses 
 directly in the formation of first sugar. In one, the water 
 
136 SUGARHOUSE AND REFINERY METHODS 
 
 of the molasses of the first massecuite is practically all 
 boiled away, and the hot molasses of the previous " strike " 
 is injected at the right moment, thinning the whole mass 
 sufficiently to allow it to run out of the pan. Sugar is 
 crystallized out in this way, and the molasses is lowered in 
 purity. In another method the molasses is thinned to the 
 consistency of meladura, and an amount, dependent on its 
 purity, is used to build up the grain during the latter stages 
 of the boiling of the first sugar. Only a part of the total 
 first molasses can be utilized in this way, the rest being 
 made into "second sugar.'' 
 
 The second sugars are polarized, and the tests for Brix 
 and purity, as well as the polarization, made on the second 
 molasses. This latter is often worked up for a third sugar, 
 but if the processes of extraction of the two sugars are 
 skillfully carried out, most raw juices will not pay for a 
 third working. A good yield of "thirds" does not by any 
 means always indicate good work. The second sugars are 
 often remelted to a sirup, and worked up with meladura 
 into first sugars. In some cases the sugar itself is put into 
 the first massecuite in the mixer. 
 
 The chemical control of a raw-sugar house carrying on 
 the process in the general manner outlined is for two 
 objects: (i) the guidance of the daily routine of the 
 house; (2) an accurate estimation of the total yields and 
 losses during a definite period of running. 
 
 As the sugarhouse is running continuously, night and 
 day, most of the material in process is distributed through 
 the house, and constantly undergoing such change that 
 any daily estimate of the yields and losses during the actual 
 running is only an approximation too rough to be of value 
 
SUGARHOUSE AND REFINERY METHODS 137 
 
 in calculating the efficiency of the work. The weight of 
 the cane and that of the juice, giving the extraction, can 
 be estimated with reasonable accuracy, but, as most houses 
 are arranged, this is the only daily calculation which is of 
 value as showing the total actual work accomplished. 
 Usually it is necessary to shut down the house at least 
 once a week for half a day or more for overhauling the 
 machinery, and particularly for cleaning the copper heat- 
 ing surfaces of the evaporating and clarifying apparatus. 
 The copper becomes badly fouled by the end of a week 
 from the deposits from the juice, necessitating a thorough 
 cleaning, usually given by boiling out with very dilute 
 hydrochloric acid. 
 
 At the time of shutting down, all cane and thin juices 
 are worked up, and usually all, or most, of the meladura. 
 The first sugars are worked up, except what may be repre- 
 sented in any meladura (and in some cases in the first 
 molasses, when this is worked into the first boilings 
 directly). Hence, pans and all evaporating and clarifying 
 apparatus are empty. There are usually many tons of 
 second sugars in process which must be estimated before 
 the work of the house can be ascertained. All the sugar 
 represented in this "stock in process" is carefully calcu- 
 lated, first, by determining the weight of the different prod- 
 ucts from their densities and the volume of the containers, 
 these latter being among the constants calculated once for 
 all, and tabulated in the laboratory records. From the 
 purity figures of the first molasses and meladura, similar 
 calculation constants can be established, by which the 
 yield of sugars from the stock in process can be rapidly 
 estimated. 
 
138 SUGARHOUSE AND REFINERY METHODS 
 
 From the amount of first and second sugars shown to be 
 in process by the figures of the " stock in process" book, 
 must be deducted, obviously, the corresponding sugars 
 held in process at the end of the previous working period. 
 
 In the estimation of the work of a sugarhouse during 
 the running period, from one clean-up to the next, the 
 scheme of calculation would be somewhat as follows : 
 
 STOCK WORKED UP 
 
 A. Weight of cane ground. From the weighers' books. 
 
 B. Weight of juice extracted. 
 
 Weighed directly by automatic scales, or determined 
 from number of defecators of known volume, in gal- 
 lons, which can be expressed in pounds by equivalents 
 calculated on the Brix, at the temperature at time of 
 gauging. (Maceration water deducted by calculation, 
 based on Brix determinations of the normal and 
 diluted juice.) 
 
 C. Fibre in the bagasse. 
 
 D. Weight of sugar in the press cake. 
 
 Obtained by polarization and weight of total cake ; the 
 latter by actual weighing, or estimated from number 
 of presses filled and calculated weight of cake per 
 press. 
 
 E. Weight of first sugar manufactured. 1 From the 
 
 weighers' books. 
 
 F. Weight of second sugar manufactured. From the 
 
 weighers' books. 
 
 1 If the second sugars are remelted and worked up into first sugars, allow- 
 ance must be made accordingly. 
 
SUGARHOUSE AND REFINERY METHODS 139 
 
 STOCK IN PROCESS 
 
 G. Weight of first and second sugar represented in the 
 
 meladura in process. 
 
 Calculated from the number of gallons in tanks, by 
 
 equivalents per gallon, based on the purity and Brix. 
 
 H. Weight of second sugar represented in first molasses. 
 
 Calculated from gallons in tanks, by equivalents, based 
 
 on the Brix and purity of the molasses. 
 I. Weight of second sugar represented in the second 
 
 massecuites, in cars and crystallizers. 
 Calculated from weight in pounds of massecuites, esti- 
 mated from volumes of containers and Brix, using 
 purity equivalents. 
 J. Weight of sugar in second molasses. 
 
 Calculated from polarizations and first molasses and 
 second massecuites in process. 
 
 From the above data are obtained the following, which 
 are expressed either as percentages of sugar on the weight 
 of cane, or on the weight of sugar in the cane : 
 
 (1) The extraction of the juice. 
 
 (2) The sugar in the cane. 
 
 (3) The sugar received into the boiling house. 
 
 (4) The loss of sugar in the bagasse. 
 
 (5) The loss of sugar in the filter-press cake. 
 
 (6) The yield of first sugar. 
 
 (7) The yield of second sugar. 
 
 (8) The loss of sugar in the second molasses. 
 
 The sum of the percentages of yields and losses will not 
 balance the per cent of sugar in the cane by .2-.4 per 
 cent of the weight of the cane. This difference is known 
 
140 SUGARHOUSE AND REFINERY METHODS 
 
 as " undetermined loss," and may be possibly due to 
 "chemical losses/' in which sugar is destroyed by inversion 
 or other chemical change in 
 
 (a) Clarifying. 
 
 (b) Evaporating. 
 
 (c) Crystallizing. 
 
 (d) From fermentation in tanks and other apparatus. 
 
 (e) Chemical changes in second massecuites from fer- 
 ments, molds, or obscure chemical changes. 
 
 Or "mechanical losses" from 
 
 (f) Entrain men t. 
 
 (g) Leaks and spills from accidents. 
 (ft) Losses in cleaning out apparatus. 
 
 The destruction of sugar in process is by no means well 
 understood. Refinery experiments in Europe have shown 
 that in every pan boiling (" strike ") about .4 per cent of 
 the sugar is destroyed. Undoubtedly some chemical loss 
 occurs in the evaporating and clarifying processes. To 
 this may be added "apparent" loss due to errors inherent 
 in polariscope measurement, which, according to some 
 authorities, amount to some tenths of a per cent. 
 
 Fermentation losses in any part of the house under 
 ordinary conditions of work are inexcusable. Absolute 
 cleanliness and a free use of lime and steam in spots liable 
 to infection should eliminate this trouble in a properly 
 designed sugarhouse. * 
 
 1 In Louisiana sugarhouses certain bacterial organisms, notably leuconostoc 
 mesenterioides, have destroyed much wagon sugar, transforming the sucrose 
 into dextran, a pentose gum which is a close analogue of dextrin. 
 
 In Porto Rico, the writer has observed leuconostoc in one or two instances 
 in the raw juice tanks, where, in a few hours, it has grown enough to com- 
 pletely clog the juice pumps. The growth was easily removed and did not 
 return. Leuconostoc seems to be a characteristic of unripe canes. 
 
SUGARHOUSE AND REFINERY METHODS 14! 
 
 Some mechanical losses will occur, necessarily in clean- 
 ing, but they can be largely controlled by good manage- 
 ment, provided the house is working uniformly. Frequent 
 stoppages necessarily increase these losses. 
 
 All tanks and other containers should be numbered, and 
 an accurate record of their volumes be kept. Tank vol- 
 umes are most easily figured by measuring in gallons per 
 inch of depth of liquor. The total amount of liquor in a 
 tank can then be quickly calculated by gauging with a 
 measuring rod and multiplying by the factor giving gallons 
 per inch for that tank. Defecators and other apparatus 
 with irregular bottoms or containing coils can be conven- 
 iently calibrated by filling the irregular section with water, 
 and dropping the contents into a tank of known capacity. 
 
 The above rough outline of a scheme of control for the 
 yields and losses of a West Indian sugarhouse is only 
 suggestive of the way such work is done. The details 
 may vary much with the working of the house and the 
 facilities given the chemist, and, as already said in the 
 opening of the chapter, fundamental principles should be 
 mastered rather than that details of methods in any par- 
 ticular sugarhouse should be copied, as the chemist must 
 design his own scheme of control to fit the peculiar re- 
 quirements of his house and the time and facilities at his 
 disposal. 
 
 It hardly need be said that the whole scheme of 
 chemical control is absolutely dependent on the accuracy 
 of the sampling. Too little attention is paid to this in 
 many houses. Obviously, the chemist cannot personally 
 take every sample himself where the house is running 
 continually night and day. Men in charge of sampling 
 
142 SUGARHOUSE AND REFINERY METHODS 
 
 should be trustworthy and intelligent, for negligence and 
 incompetence here cannot be made good by the most care- 
 ful laboratory work. In Europe, in the beet-sugar houses, 
 there is a much better realization of the importance of the 
 sampling, and elaborate registering and sampling apparatus 
 is in use much more generally. That such apparatus is 
 profitable seems unquestionable. 
 
 Beside the measurements and determinations which have 
 reference to the accurate estimation of the work of the 
 house, there are others which are valuable for the control 
 of the daily factory operations. Some of the laboratory 
 determinations for this purpose have already been dis- 
 cussed, such as acidity tests, density determinations of the 
 meladura, etc. ; but aside from these there are daily records 
 kept for a definite twenty-four-hour period, starting at some 
 fixed hour, say from six o'clock in the evening of one day 
 to the same hour of the next. These figures are mainly of 
 value in determining the efficiency of the various apparatus, 
 as well as the sugarhouse as a whole, by giving the rate 
 at which the product is worked up. Such figures are, for 
 instance, bulletins of the starting and stopping of the mills, 
 and of the number of defecators, 1 filter presses, crystallizers, 
 etc., filled and emptied. These records, kept conspicuously 
 placed for quick inspection, show at once the work of the 
 house from hour to hour as well as for the complete day\ 
 run. At the end of the twenty-four-hour period these 
 should be recorded in the laboratory books. 
 
 1 One large Cuban sugarhouse has recently installed a watchman's clock 
 system for electrically recording the defecator tallies. Numbered magneto 
 call-boxes are placed at each defecator, from which workmen send signals 
 which are recorded on the dial of a watchman's clock as each defecator 
 is filled. 
 
SUGARHOUSE AND REFINERY METHODS 143 
 
 The best records of the work of the vacuum pans are 
 made by recording vacuum-gauges. These give a continu- 
 ous plot of the gauge readings during the whole twenty- 
 four-hour period, so that the work of the pan is known 
 at any hour of the day or night, within errors of a few 
 minutes. 
 
 These curves have been found to be of great value, as 
 they give permanent records of (i) the exact time the boil- 
 ing is started ; (2) the length and efficiency of the evapora- 
 tion previous to graining ; (3) the time the graining begins ; 
 (4) the length of the finishing period; (5) the exact time 
 the strike is " dropped " ; (6) the length of time that the 
 pan is idle, which, in molasses-sugar strikes, is a measure 
 of the time taken in filling wagons or crystallizers. Much 
 other instructive information is often obtained from the 
 gauge charts, such as the time and extent of irregularities 
 in working of the condensing apparatus, etc. In connec- 
 tion with these records, those taken by recording gauges 
 of the "live " and " exhaust " steam pressure are important, 
 as they give data which are legitimately in the province of 
 chemical control, and explain many irregularities in the 
 work of the house which otherwise are interpreted by mere 
 guess. 
 
 Such gauges should be placed in the laboratory or other 
 office where they can be cared for. The greatest care 
 should also be exercised in the installation of the connect- 
 ing piping to avoid leaks and to insure the proper trapping 
 of condensed vapor. If these precautions are not carried 
 out, and such apparatus treated with the same care as any 
 other instruments of high precision, it is worse than useless 
 to install it. 
 
144 SUGARHOUSE AND REFINERY METHODS 
 
 In 'most first-class cane sugarhouses the chemist is the 
 superintendent of sugar manufacturing, as he should be. 
 
 Beet-sugar Manufacture. The conditions governing 
 beet-sugar manufacture, as well as the chemical differences 
 between beet and cane juices, have resulted in making it 
 radically different from cane-sugar manufacture in many 
 details of process. In this country at least, 1 refined sugar 
 is made directly from the beet, and the extraction is uni- 
 versally by " diffusion," the extracted pulp being useless 
 for fuel, but a valuable food for cattle. As beet sugar is 
 manufactured in regions where fuel is comparatively cheap 
 and water is abundant, the diffusion process can be used 
 to great advantage. 
 
 As beets are not only bought by the sugarhouse, but 
 also selected with great care for seed on tests mainly based 
 on their polarization, beet testing is one of the most im- 
 portant and extensive operations of the factory laboratory. 
 By this method of careful seed selection, the sugar content 
 of the beet crop as a whole has been more than doubled in 
 the past century. 
 
 In a large establishment, in seed testing particularly, 
 often several thousand polarizations have to be made in 
 a day. Much ingenious and labor-saving apparatus has 
 been especially designed to meet the requirements of this 
 great volume of work. Probably no industry has had its 
 technology and special analytical methods more thoroughly 
 exploited by eminent authorities than beet-sugar manu- 
 facture. The reader is, therefore, referred to the works 
 
 1 In many countries, raw cane sugars are directly consumed as food. In 
 fact, such sugars were common in our own groceries a generation ago. Raw 
 beet sugars, on the contrary, are quite unfit for food, owing to their vile taste. 
 
SUGARHOUSE AND REFINERY METHODS 145 
 
 of Stohmann, Friihling, Claassen, Sidersky, Spencer, and 
 others for details of these processes and methods. 
 
 Diffusion. In this process the beets, in a finely chipped 
 or sliced state, are subjected to the action of hot water. 
 It can be considered as a kind of lixiviation process, but is 
 to a considerable degree a clarification process as well, 
 as the hot water tends to coagulate the albuminoids in the 
 plant tissues. These matters are retained, together with 
 other colloidal substances, by the cell membranes, which 
 allow the sugar and salts -to diffuse freely through. The 
 beets, usually brought to the factory by small flumes of 
 swiftly running water, are passed into a washer and then 
 to the " cutters," where they are reduced by notched knives 
 on a rapidly revolving wheel to a form resembling French 
 fried potatoes. These "chips" ("cosettes") are fed into 
 the "diffusion battery," consisting of ten or fifteen tall 
 cylindrical (closed) iron tanks ("cells"), holding ten tons 
 or more. These tanks are constructed to carry a moderate 
 pressure and arranged so that the liquors can be passed 
 from one to the other. The hot water, about equal in 
 weight to the chips, is allowed to stand on the chips in 
 a " cell " for twenty minutes or so, and then is passed to 
 the next cell. When the battery is in operation, it is 
 usually run so that all the cells are full except two, one 
 which is filling, the other dumping. The diffusate, before 
 leaving the battery, finally passes over at least one cell of 
 fresh chips, and the work is commonly so arranged that 
 it is the second diffusate of the three previous ones. Dif- 
 fusion gives more extraction and a purer juice than any 
 milling process, but dilutes the juice 15 or 20 per cent. 
 The exhausted chips, after the excess of water is removed 
 
146 SUGARHOUSE AND REFINERY METHODS 
 
 by a specially designed press, are fed to live stock, the 
 surplus being stored in covered trenches by a process of 
 ensilage. 
 
 Clarification. This differs radically from cane-sugar 
 clarification, being much more elaborate than the former. 
 This fact is chiefly due to the larger amount of albuminoids 
 in beet juices and the greater difficulty of removing them, 
 and also is a result of the conditions of manufacture 
 already alluded to which favor the manufacture of refined 
 sugar. The process is known as the " carbonatation " 
 method, and in its essentials consists in treating the juice 
 with a large excess of lime (about 2 per cent, although 3 
 per cent or more is often used) heating to 80, and then 
 precipitating the lime and coagulated albuminoids with 
 carbon dioxide, which also decomposes the calcium sucrate 
 formed. 1 The juice is then passed through "bag filters" 
 or filter presses. In this first carbonatation, the process 
 is not complete, the juice being still somewhat alkaline. 
 It is now treated with sulphur dioxide, and again with 
 carbon dioxide till practically neutral, and the slight pre- 
 cipitate formed removed by "mechanical" filters, which 
 are small closed tanks holding thirty or more flat bags 
 stretched on wire frames. The juice filters from outside 
 into the bags, and passes out by pipe connections in the 
 frames. 
 
 A further treatment of the concentrated sirups with 
 sulphur dioxide is usually given. The lime necessary for 
 clarification is made at the factory by burning limestone in 
 immense iron kilns similar in shape to blast furnaces, 
 
 1 Carbonatation in modified form has been introduced in Java cane-sugar 
 houses, but its advantages are questionable in raw cane-sugar manufacture. 
 
SUGARHOUSE AND REFINERY METHODS 147 
 
 so arranged that the carbon dioxide can be collected and 
 pumped into the carbonatation tanks. 
 
 The carbonatation process is possible in beet clarifica- 
 tion, owing to the absence of glucose sugars, for, as already 
 stated, these are decomposed by excess of lime into slimy 
 humus products which are hard to remove, and also give a 
 brown (caramel) color to the sugar, very difficult to bleach. 
 Normal beets are practically free from glucose sugars, but, 
 in American practice, beets often have to be worked up 
 which from various causes (unripeness, freezing, etc.) do 
 contain considerable quantities of glucose. 
 
 Such beets require modification of the carbonatation pro- 
 cess to be worked successfully, the heating of the alkaline 
 solutions being reduced as far as practicable, as well as 
 the amount and duration of the alkaline state, while sulphur 
 dioxide is used more freely to keep the clarified liquors 
 neutral or even faintly acid. 
 
 The evaporation and crystallizing processes are identical 
 with those of cane-sugar manufacture ; so too, in its essen- 
 tials, the centrifugal purging, the washing process during 
 the purging being an important feature, as the sugar is 
 turned out white. Subsequently, the sugar is passed 
 through a "granulator," a long, slowly revolving, nearly 
 horizontal drum, heated by a second internal steam drum. 
 The sugar, which comes from the centrifugals with about 
 2.5 per cent of moisture, is thoroughly tossed about in the 
 granulator, and perfectly dried, emerging as the " granu- 
 lated sugar" of the grocer, and practically indistinguish- 
 able from the refinery product. 1 
 
 1 Beet sugars refined in this manner do not hold their color quite as well as 
 the bone-black refined product. On long standing, they gradually assume a 
 slight yellow tint. 
 
148 SUGARHOUSE AND REFINERY METHODS 
 
 Second sugars, and occasionally thirds, are made from 
 the purer sirups from the washing of the first sugars, being 
 usually grained in crystallizers. The beet molasses (from 
 normal beets) differs radically in many important charac- 
 teristics from cane molasses. It has about 80 per cent 
 of solids and averages about 50 per cent of sucrose, 10 per 
 cent of ash, and 20 per cent of organic " non-sugar," largely 
 nitrogenous, consisting of albuminoids and decomposition 
 products of albuminoids. More than half of the mineral 
 matter is potassium in combination with organic acids 
 which are strongly melassagenic. This means that these 
 bodies by their presence prevent the sugar from crystalliz- 
 ing, so that it is practically impossible to extract it by 
 further boiling or ordinary methods of clarifying. 
 
 Many ingenious processes have been devised for extract- 
 ing this sugar from the beet molasses. One which is 
 quite often used is osmosis, in which the hot diluted mo- 
 lasses is made to flow through an " osmogene," very similar 
 in appearance to a filter press, but composed of pairs of 
 cells separated from each other by partitions made of 
 parchment paper. Hot water flows on one side of the 
 partition, the dilute molasses on the other. Many of the 
 more soluble potash and other salts diffuse more rapidly 
 than the sugar. By regulating the flow and temperature, 
 sufficient melassagenic material of this nature can be re- 
 moved, so that the molasses, on boiling in the vacuum pan 
 and treatment with crystallizers, is said to yield some 12 
 per cent of its sugar. By further treatment of the mo- 
 lasses from the osmose sugar by a second osmosis and 
 boiling, it is stated by Stohmann that 12 per cent of its 
 sugar can again be obtained. 
 
SUGARHOUSE AND REFINERY METHODS 149 
 
 Another method of extracting sugar from beet molasses, 
 which is used considerably, is known as Stefferis pro- 
 cess. In this the diluted molasses is treated with lime 
 till the sugar is converted into monocalcium sucrate, and 
 into this solution is put fresh-burnt lime in very small por- 
 tions at a time, while the temperature is kept at 15 C. by 
 a cooling apparatus. In this way, finally, all the sugar is 
 precipitated as a tricalcic sucrate, which can be filtered in 
 filter presses, washed, and worked back into the juice, being 
 substituted for lime in the carbonatation process. Stron- 
 tium and barium hydrates have been substituted for lime 
 in similar processes. The only impurity which is carried 
 along with the sugar in this process is raffinose. 
 
 It will be seen from the above outline of beet-sugar 
 factory methods that the scheme of chemical control 
 will differ considerably from that of the cane-sugar house. 
 Reference has already been made to the analysis of beets 
 for seed and for establishing the purchase price, there 
 being no difficulty in obtaining a representative sample, 
 as in the case of cane. The usual method of obtaining the 
 sample is by making a boring with a cylindrical rasp through 
 the beet diagonally in a direction which experiment has 
 shown to give a section representative of the average beet 
 contents. The rasp is made to revolve very rapidly, and is 
 so constructed that the raspings are retained in the hollow 
 cylinder of the tool. In other rasps a wedge-shaped section 
 is cut out of the beet, and drops into a metallic box. 
 
 Determination of Sugar in Beets. The usual way is 
 by the "hot digestion" method. The normal weight of 
 pulp is washed into a funnel-mouthed flask, graduated to 
 hold 201.35 cubic centimeters, the 1.35 cubic centimeters 
 
I $0 SUGARHOUSE AND REFINERY METHODS 
 
 being the allowance for the "marc" or pulp and the vol- 
 ume of the precipitate, 5 to 7 cubic centimeters of a basic 
 lead acetate solution of a density of 1.25 having been pre- 
 viously run into the flask. The contents of the flask are 
 nearly made up to the mark with water, and heated on a 
 water bath for 30 minutes at 80 C. after thorough shaking 
 and the addition of a drop or two of ether to dispel the 
 foam. It is then acidulated with acetic acid and made up 
 to the mark after cooling. The polarization is made in a 
 4-decimeter tube when practicable, to avoid doubling the 
 reading. If a 2OO-cubic-centimeter flask is used, the 
 weight of the pulp taken is 25.87 grams, instead of 
 26.048. 
 
 The analysis of the juice is made by the " indirect " 
 method. The beet is cut up into small pieces and put 
 through a screw fruit press, or, much better, rasped, and 
 pressed in a very powerful laboratory press made for the 
 purpose. The polarization and purity tests are made as 
 for cane juices. The per cent of sugar in the beet is 
 often calculated from the juice polarization by taking the 
 arbitrary factor .95. 
 
 Ash Determination. The methods of analysis of the 
 diffusion juice are practically the same as for cane juices, 
 but as the mineral matter plays such a large part in caus- 
 ing manufacturing losses, owing to its comparatively large 
 amount and its strongly melassagenic action, its estimation 
 is important. This is done by a determination of the ash 
 of the juice. The ordinary method of making an ash 
 determination of a saccharine solution is to dry 10 grams 
 in a platinum dish, on a water bath, and then burn off the 
 organic matter in a " low temperature " muffle, which is 
 
SUGARHOUSE AND REFINERY METHODS 151 
 
 kept at a dull red heat, not over 750 C. The organic 
 matter is rapidly consumed at this temperature, which is 
 not sufficient to volatilize the chlorides. Several methods 
 have been devised for overcoming the difficulty of the 
 excessive swelling of the carbonized mass in the prelimi- 
 nary stages of the burning, which is characteristic of carbo- 
 hydrate substances. A very small lump of vaseline put in 
 the dish before igniting works very well. In beet products, 1 
 however, it is customary to use Scheibler's method, and 
 add a few drops of concentrated sulphuric acid, just suffi- 
 cient to moisten the dried residue, which will then burn 
 without making a bulky coal in the preliminary stages. 
 The "sulphated ash," as it is called, obviously is heavier 
 than would be an untreated ash, owing to the higher mo- 
 lecular weight of the sulphuric radical. Scheibler found 
 that in beet products a deduction of one tenth from the 
 weight of the sulphated ash gave the equivalent of the 
 normal ash. The per cent of sugar divided by the per cent 
 of ash in a beet product is known as the " saline coeffi- 
 cient," and is an instructive figure to the beet-sugar 
 manufacturer. Good beets give a coefficient of 20 or 
 over. 
 
 Manufacturing Loss. The first loss is in the diffusion 
 chips and in the wash water expressed from the chips by 
 the chip press. This approximates about .4 per cent on 
 the weight of the beets. 
 
 The next losses occur in the carbonatation scums, which 
 are polarized as described for cane-juice filter cake, except 
 that care must be taken always to acidulate the solution 
 
 1 Ash determinations should be made on the filtered solutions in case of 
 raw sugars which contain sand and other foreign matter. 
 
152 SUGARHOUSE AND REFINERY METHODS 
 
 with acetic acid to decompose the lime sucrates present in 
 the beet filter cake. A further loss occurs in the mechani- 
 cal filtrations of the sirups, averaging .05 per cent. The 
 chemical and other mechanical losses, which are those 
 which have been enumerated under cane-sugar manufac- 
 ture, bring the actual total losses to an average of about 
 i per cent, although they figure .4 per cent or more 
 larger, a result due, according to some authorities, to errors 
 of polarizations, which are usually additive. 
 
 Quotient of Purity Tests of Beet Products. The method 
 of determining quotient of purity described for cane juices, 
 in which the total solids is assumed to be given by the 
 Brix reading, invariably gives too low results, owing to the 
 large amount of mineral matter present, which has an 
 influence on the density over twice as great as that of 
 sugar. A solution of calcium chloride of I per cent, for 
 instance, would read nearly 2.5 Brix. Hence, it is 
 necessary for accurate work to obtain the total solids 
 by drying. 
 
 Drying of Saccharine Products. It is very difficult to 
 determine moisture accurately in sirups and other solu- 
 tions of sugar, because as the drying proceeds, an im- 
 pervious varnish of the saccharine material forms over 
 the surface, which confines the moisture of the lower 
 layers. For satisfactory drying, the solution during dry- 
 ing must be distributed in very thin films over a large 
 surface. This is done most effectively by diluting the 
 substance to a thin sirup and pouring it over clean sand 
 or pumice stone, and then evaporating at a temperature of 
 105 C. in a hot-air oven, till a practically constant weight 
 is obtained, practically constant, because the drying is 
 
SUGARHOUSE AND REFINERY METHODS 153 
 
 beset with another difficulty, the gradual increase in weight 
 due to the oxidation of the sugar, which takes place rapidly 
 in the dried product at the air-bath temperature. The 
 usual method of determining the point of dryness is 
 when the loss in weight does not exceed .2 per cent 
 per hour. 1 
 
 This oxidation error is mitigated by drying in a vacuum 
 at 70 C. Lobry de Bruyn and Van Laent 2 have used a 
 vacuum apparatus arranged so that in the final stages of 
 drying the vapors are passed over phosphorus pentoxide. 
 Brown, Morris, and Millar have dried most of the common 
 carbohydrates with this apparatus, and determined their 
 density influences per gram in 100 cubic centimeters for all 
 concentrations up to about 25 per cent. This apparatus 
 is somewhat complicated and the process tedious for com- 
 mercial work. The method almost universally used in 
 refineries and sugarhouses is drying in the hot-air bath 
 at 105. 
 
 Weisberg has worked up a table of coefficients for trans- 
 forming "apparent quotients " (those obtained by the Brix 
 spindle) into true values. It is said to give correct results 
 when the solution of the beet product is made up to the 
 normal (saccharimeter) concentration of 26.048 grams in 
 100 Mohr cubic centimeters. Usually two or three times 
 the normal weight is taken in the corresponding volume to 
 allow of sufficient solution for the Brix determination. The 
 following is the table of Weisberg : 
 
 1 The United States Custom House method for determination of moisture 
 in molasses and sirups is to spread I to 2 grams over the bottom of a flat dish 
 at least 7 centimeters diameter, and dry for two hours at 100 C. 
 
 2 Rec. Trav. Chim., 13, 218. 
 
154 
 
 SUGARHOUSE AND REFINERY METHODS 
 
 APPARENT QUOTIENT 
 
 COEFFICIENT 
 
 APPARENT QUOTIENT 
 
 COEFFICIENT 
 
 57.0 
 
 
 .054 
 
 79.0 
 
 
 .O2O 
 
 57-5 
 
 
 .052 
 
 8o.O 
 
 
 .019 
 
 58.0 
 
 
 .050 
 
 81.0 
 
 
 .018 
 
 59.0 
 
 
 .046 
 
 82.0 
 
 
 .017 
 
 60.0 
 
 
 .044 
 
 83.0 
 
 
 .Ol6 
 
 61.0 
 
 
 .042 
 
 84.0 
 
 
 .015 
 
 62.0 
 
 
 .040 
 
 85.0 
 
 
 .014 
 
 63.0 
 
 
 .038 
 
 86.0 
 
 
 .013 
 
 64.0 
 
 
 .036 
 
 87.0 
 
 
 .012 
 
 65.0 
 
 
 034 
 
 88.0 
 
 
 .Oil 
 
 66.0 
 
 
 033 
 
 89.0 
 
 
 .OIO 
 
 67.0 
 
 
 .032 
 
 90.0 
 
 
 .009 
 
 68.0 
 
 
 .031 
 
 91.0 
 
 
 .008 
 
 69.0 
 
 
 .030 
 
 92.0 
 
 
 .007 
 
 70.0 
 
 
 .029 
 
 93-o 
 
 
 .OO6 
 
 71.0 
 
 
 .028 
 
 94.0 
 
 
 .005 
 
 72.0 
 
 
 .027 
 
 95 -o 
 
 
 .OO4 
 
 73-o 
 
 
 .026 
 
 96.0 
 
 
 .003 
 
 74.0 
 
 
 .025 
 
 97.0 
 
 
 .002 
 
 75.0 
 
 
 .024 
 
 98.0 
 
 
 .OO2 
 
 76.0 
 
 
 .023 
 
 99.0 
 
 
 .OOI 
 
 77.0 
 
 
 .022 
 
 IOO.O 
 
 
 .OOO 
 
 78.0 
 
 
 .O2I 
 
 
 
 Weisberg's method is particularly adapted for determin- 
 ing the quotient of purity of massecuites. 
 
 The chemical determinations necessary for controlling 
 the daily work of the beet-sugar house are evidently much 
 more various than those of cane-sugar manufacture, and 
 comprise analyses of the limestones used in the kiln, as 
 well as the lime itself, the kiln gases used in carbonatation, 
 alkalinity tests of the juices and sirups in process, besides 
 occasional analyses of fuel, boiler deposits, fertilizers, etc. 
 
SUGARHOUSE AND REFINERY METHODS 155 
 
 Moreover, there is much chemical work which could be 
 done to advantage, both in cane and beet sugar laborato- 
 ries, not only directly bearing on the work of the factory, 
 but in research work on problems constantly arising. How- 
 ever, very few factory laboratories have the facilities for 
 more than the necessary routine control work. 
 
 Refinery Methods. The refinery takes raw sugars of 
 all sorts, the great bulk of which is turned into a product 
 which is practically chemically pure white sugar, mostly in 
 granulated form, although considerable is manufactured 
 into the various forms of " lump " or "loaf" sugar, and 
 moist " yellow " sugars. 
 
 As has already been explained, raw sugar reaches the 
 refinery in many forms and qualities. There are, however, 
 practically four classes of sugars which are recognized : 
 (i) first centrifugal cane sugars, (2) second, or molasses, 
 and muscovado sugars, (3) beet sugars, corresponding to 
 cane first sugars, (4) " jaggerys " and other crude products 
 of primitive manufacture. 
 
 With the exception of beet sugar, the price of the sugars 
 in each class is directly fixed by the polarization. In valu- 
 ing beet sugars, the amount of mineral matter (ash) is also 
 taken into consideration, as this is largely a constituent of 
 melassagenic salts. The custom is to subtract five times 
 the ash per cent from the polarization in valuing the sugar. 
 For instance, a beet sugar polarizing 96 per cent with 
 an ash of 1.25 per cent would be rated as a cane sugar 
 polarizing 89.75 per cent. This is based on actual results 
 obtained in European refinery practice, but is said by some 
 authorities not to apply except to what are known as 
 "export sugars,'* the only kind of raw beet sugar which 
 
156 SUGARHOUSE AND REFINERY METHODS 
 
 reaches the United States. The ash of the lower grade 
 cane sugars is also often determined in order to classify 
 them. 
 
 The better grade of raw sugars are at once washed in 
 large centrifugal machines, by which 90 per cent or more 
 is separated as crystals of practically white sugar of a 
 purity of about 99.5, for the greater part of the impurities 
 exist as a coating on the crystals, and so can be collected 
 in the wash sirups. 
 
 The washed sugar is dissolved in the " melters " to 
 a sirup of about 30 Beaume, which is defecated in a 
 manner similar to that used in raw-sugar manufacture, 
 although other coagulants are often used with lime, the 
 suspended solid matters customarily being removed by 
 passing through "bag filters." The clear sirups are then 
 decolorized by bone black in the " char filters," and the 
 practically colorless sirups boiled in vacuum pans and the 
 sugar separated and washed white in centrifugal machines 
 by the methods already described. The sugar is dried in 
 granulators, and is ready for market after sifting into 
 different grades of fineness and packing. The sirups 
 from the preliminary washing of the raw sugar are mixed 
 with the " meltings " of the lower grade sugars and sub- 
 jected to an identical process, in most cases precipitants 
 being used with the lime for more effective clarification. 
 Finally, the washings from the bone-black filters and 
 other apparatus, and from the bag-filter scums, if not 
 utilized in the melting, are concentrated in a multiple- 
 effect evaporator, and worked into the other liquors. The 
 sirups from the refined sugars are reboiled in the vacuum 
 pan for sugar, the less pure ones being used for charging 
 
SUGARHOUSE AND REFINERY METHODS 157 
 
 after the grain is formed. When the purity of the sirups 
 from the reboiling falls below a certain value, say about 
 84, it is no longer profitable to boil them in the pan without 
 further refining, unless to make soft yellow sugars. These 
 sirups are therefore added to others in process at a stage 
 depending on their purity, or boiled to low-grade sugar, 
 which is remelted. In fact, practically the whole work of 
 the refinery is governed by the purity tests of the liquors 
 in process, by which is determined the most effective way 
 to combine the different lots for most economical refining. 
 When it is known that in the larger refineries 1500 tons or 
 more of sugar are refined daily, it will be readily seen that 
 failure to take advantage of the most effective blending 
 or working up of the diverse sirups and liquors in process 
 may mean large money loss. Finally, when the purity of 
 the sirups put constantly back in process in different ways 
 falls below about 45 actual purity, it is no longer profitable 
 to re-work them for sugar, and they are sold as " barrel 
 sirups" (English, " treacle") for use as food sirups or in 
 brewing. 
 
 From what has been said in this rough outline of the 
 complicated process of refining, it will be evident that, 
 beside the polarization of the raw sugars and the refined 
 products, the determination of the quotient of purity of the 
 many and various liquors in process will be an indispensa- 
 ble function of the laboratory ; in fact, its most important 
 work, as by it is controlled the entire arrangement of the 
 refining of the different stock in process. Perhaps the 
 next most important routine work of the refinery labora- 
 tory is the control of the bone-black filtration. Bone black 
 is indispensable as a decolorizer in sugar refining. It is 
 
158 SUGARHOUSE AND REFINERY METHODS 
 
 one of the greatest items of cost, as the material is expen- 
 sive, requires elaborate machinery for its handling, and 
 undergoes considerable loss by disintegration in treatment. 
 About a pound of bone black is required per pound of 
 sugar decolorized. After bone black has been used a short 
 time, its pores become clogged, and it loses its decolorizing 
 power. It is then washed and partially dried by steam, 
 passed through a dryer, heated to dull redness in tubular 
 retorts 1 to consume the organic material which clogs its 
 pores, and finally passed through revolving screens to 
 remove the finer disintegrated part, which is rejected as 
 " spent black/' still valuable for many purposes, from the 
 phosphate it contains. New black often has to undergo 
 a preliminary treatment with dilute acid and a washing 
 known as "tempering" before it can be used. If the 
 various processes of " revivifying " the black are not car- 
 ried out properly, the pores of the revivified black become 
 clogged with carbonaceous and mineral matter, to the great 
 loss of its efficiency. Hence, the daily condition of the 
 black must be closely followed by the chemist by analysis, 
 particularly determinations of the carbon and lime con- 
 tent. 2 The amount of phosphate is also important as a 
 measure of the durability of the black. 
 
 As a rule, the chemist of a refinery has little to do with 
 :he active management of the refinery, or in fact with the 
 
 1 Sometimes the bone black is subjected to a roasting process known as 
 * decarbonizing." This volatilizes considerable of the organic matter clogging 
 the pores of the black, which would otherwise be deposited as carbon in its 
 passage through the retorts. Formerly the bone black was allowed to stand 
 in heaps to allow this organic matter to be destroyed by fermentation. 
 
 2 For methods of bone-black analysis, see Tucker, "Manual of Sugar 
 Analysis." 
 
SUGARHOUSE AND REFINERY METHODS 159 
 
 calculation of yields and losses. These calculations are so 
 extensive and complicated that they are usually made part 
 of the bookkeeping of the office force, under direction of 
 the superintendent and his assistants, the laboratory records 
 being practically confined to the actual analytical work. 
 
 The losses in a refinery, according to European practice, 
 are said to be .5 per cent mechanical and .55 per cent 
 chemical, on the weight of the raw sugar actually refined. 
 
CHEMICAL METHODS OF DETERMINING 
 SUGARS 
 
 ALL the common glucose and saccharose sugars, with the 
 exception of sucrose, exert a marked reducing action when 
 heated with alkaline solutions of many metallic salts. 
 This behavior is characteristic of organic compounds 
 known as " aldehydes " and " ketones," which can be con- 
 sidered as partially oxidized from hydrates (alcohols) and 
 in a transition state between the latter and the more com- 
 pletely oxidized form of the acid. Consequently, like all 
 readily oxidizable chemical compounds, they are strongly 
 reducing in their action. All the sugars are known to 
 have an aldehyde or ketone structure, being sometimes 
 classified as " aldoses " and "ketoses." 
 
 The Fehling Volumetric Method. In 1848 Fehling 
 developed a practical method for utilizing this reducing 
 property of the sugars on copper salts as a means of quan- 
 titative determination of the sugars themselves. Fehling 
 used a strongly alkaline solution of copper tartrate for his 
 metallic solution, the concentration of which was so de- 
 signed that the copper salt in 10 cubic centimeters of this 
 solution would be completely reduced to cuprous oxide, 
 when boiled with .05 gram of dextrose, under the condi- 
 tions of the process. 
 
 Fehling's original solution, according to Wiley, is made 
 as follows : 34.64 grams of pure crystallized copper sul- 
 
 160 
 
CHEMICAL METHODS OF DETERMINING SUGARS l6l 
 
 phate (free from efflorescence) is dissolved in a small 
 quantity of water (less than 300 cubic centimeters), and 90 
 grams of sodium hydroxide is also dissolved in about 600 
 cubic centimeters of water in which is subsequently dis- 
 solved 150 grams of potassium tartrate. The solutions 
 are then mixed and made up to 1000 cubic centimeters. 
 Later, 173 grams of the double sodium-potassium tartrate 
 (" Rochelle salt") was substituted for the potassium tar- 
 trate. 
 
 Nearly thirty modifications of Fehling's original solution 
 have been made, the majority of which vary mainly in the 
 amount of alkali used. Owing to the fact that Fehling 
 solutions decompose spontaneously after a short time and 
 precipitate copper, the modern formulae are for two solu- 
 tions, one containing copper sulphate, the other alkaline 
 tartrate. If the copper sulphate solution is made slightly 
 acid with a cubic centimeter of sulphuric acid per liter, and 
 both solutions kept in tightly stoppered bottles of good 
 glass, they will keep indefinitely. A mixture of equal vol- 
 umes of the two solutions gives the Fehling liquor. 
 Soxhlet's formula is as follows : 
 
 Solution No. i. Copper sulphate in crystals, 69.28 
 grams in 1000 cubic centimeters of water. 
 
 Solution No. 2. Rochelle salt, 346 grams dissolved 
 in about 600 cubic centimeters of water, to which 
 is then added 100 grams of sodium hydroxide in 
 200 cubic centimeters of water. Solution made 
 up to 1000 cubic centimeters. 
 
 The original method of Fehling is a volumetric one, and 
 according to Sutton is as follows : 5 cubic centimeters of 
 
 M 
 
1 62 CHEMICAL METHODS OF DETERMINING SUGARS 
 
 each solution is measured into a small porcelain dish, the 
 resulting 10 cubic centimeters of clear deep blue Fehling 
 liquor diluted with 40 cubic centimeters of water and 
 quickly heated to boiling. The sugar solution which 
 must be at a concentration of about .5 per cent, is then 
 run in from a burette in small quantities till the blue 
 color of the copper just disappears. The volume of 
 sugar solution added to decolorize is assumed to contain 
 .05 gram if dextrose, other sugars giving different reduc- 
 tion weights. 
 
 Unfortunately, the reduction value obtained varies con- 
 siderably with the manipulation, being dependent on the 
 length of boiling, the exposure of the solution to the oxi- 
 dizing influence of the air, and the amount of sugar present 
 at different steps in the titration. Many attempts have 
 been made to improve the volumetric process so as to 
 reduce the inherent errors. 
 
 None of these improved volumetric methods seem to 
 have any advantages over the original one of Fehling, 
 when the following conditions are observed, these being 
 vital for accuracy, whatever the method used : 
 
 (i) To arrange for the concentration of the sugar solu- 
 tion, or the dilution of the Fehling liquor, so that in all 
 determinations the volume of the boiling liquid is a fixed 
 one; (2) to add at once practically all the sugar solution 
 necessary to decolorize the Fehling liquor ; (3) to carry 
 out the test under as uniform an air exposure as possible, 
 i.e. in flasks of uniform size and shape; (4) to boil with 
 the Fehling solution uniformly for a fixed period. The 
 disappearance of the copper from the solution by precipi- 
 tation can be determined conveniently by spotting a drop 
 
CHEMICAL METHODS OF DETERMINING SUGARS 163 
 
 on a tile or on the paper prepared for the purpose, and 
 testing the clear portion of the spot with potassium ferro- 
 cyanide acidified with acetic acid. 
 
 Hence, it cannot be assumed, except in very rough 
 work, that .05 gram of sugar is necessarily the exact 
 amount to discharge the color of 10 cubic centimeters of 
 Fehling liquor under the conditions of analysis. Each 
 operator should determine for himself what the reduction 
 factor is as he personally carries out the test, by standard- 
 izing the Fehling liquor with a solution of pure dextrose or 
 invert sugar. 
 
 Standard Dextrose Solution. Chemically pure anhy- 
 drous dextrose can be obtained of the dealers in pure 
 chemicals. It is, however, best to recrystallize in pure 
 alcohol before using. The principal impurity in anhydrous 
 dextrose is moisture, and as the sugar is troublesome to 
 dry, the better way is to prepare an approximately 10 per 
 cent solution, and determine the exact amount of dextrose 
 contained by means of the density taken with the pyk- 
 nometer. The density factors at 15.5 C., referred to water 
 at 15.5 C., have been worked out with great exactness by 
 Brown, Morris, and Millar. 1 For a solution of approxi- 
 mately 10 per cent, the grams of dextrose in 100 cubic 
 centimeters (Mohr, 15.5) are given by the following equa- 
 tion: w= = , where w is the number of grams in 100 
 
 .003035 
 
 cubic centimeters of solution, and <^the density. Knowing 
 the concentration of the dextrose solution, its purity can 
 be established by a determination of its specific rotatory 
 
 !/. C/iem. Soc. (London), 1897, 71, p. 73, also p. 275. 
 
1 64 CHEMICAL METHODS OF DETERMINING SUGARS 
 
 power. 1 [a]^ of an approximately 10 per cent solution of 
 dextrose at 20 C. is 52.74 according to Landolt. 
 
 Standard Invert Sugar Solution. According to Fruhling, 
 this is made as follows : 9.50 grams of pure cane sugar are 
 dissolved in 75 cubic centimeters of water in a ico-cubic- 
 centimeter flask, and 5 cubic centimeters of hydrochloric 
 acid of a density of 1.19 added, and the whole thoroughly 
 mixed. The solution is then heated in a water bath kept 
 at a temperature of 70, the flask being immersed in the 
 water up to its neck. The solution should reach the bath 
 temperature in from 2\ to 5 minutes, and the heating 
 should be continued for 5 minutes more. 
 
 The solution is then cooled to the room temperature and 
 diluted to the loo-cubic-centimeter mark. Fifty cubic cen- 
 timeters of this solution, corresponding to 5 grams of 
 invert sugar, are put into a liter flask, carefully neutralized 
 with sodium carbonate, and made up to the mark. This 
 solution, every cubic centimeter of which contains .005 
 gram of invert sugar, is used to standardize the Fehling 
 solution. 
 
 Theoretically, in the volumetric Fehling reaction,' one 
 equivalent of dextrose, of a molecular weight of 180, 
 reduces ten equivalents of crystallized copper, sulphate 
 (CuSO 4 5 H 2 O) of a total molecular weight of 2494, but 
 actually, at the same time as the sugar is being oxidized 
 the action of the alkali present is to break up the sugai 
 molecule into a complex mass of decomposition products, 
 
 1 Dextrose, like many other sugars in the crystalline state, when freshly 
 dissolved has a temporary specific rotation which gradually changes to the 
 normal value after some hours. If heated to boiling, the solution at once 
 gives the normal specific rotation. Hence, the solution should be brought to 
 a boil and cooled before polarizing. This phenomenon will be discussed later. 
 
CHEMICAL METHODS OF DETERMINING SUGARS 165 
 
 salts of numerous organic acids. As already noted, the air 
 also exerts a marked oxidation. 
 
 Many attempts have been made to devise solutions 
 doing away with the alkali, 1 but this seems essential. Any 
 decrease in quantity of the alkali, whether potassium or 
 sodium hydrate, decreases the sensitiveness of the Fehling 
 solution to reduction. Ammonia has been substituted for 
 sodium or potassium, in part or whole, by Pavy and others, 
 as the former does not act so energetically on the glucose 
 molecule. These solutions give a very sharp end point, as 
 there is no precipitate of cuprous oxide to obscure the 
 solution, and are valuable in cases where ammonium or 
 its derivatives are already present in the solution, but are 
 inconvenient, owing to the necessity of providing for a uni- 
 form ammonia content during the titration and the exclu- 
 sion of air. The reader is referred to Wiley's " Principles 
 and Practice of Agricultural Analysis," volume III, for 
 a more extended description of Fehling and similar 
 methods. 
 
 The Fehling volumetric methods are much used in sugar 
 analysis, owing to their rapidity, and are valuable where 
 small quantities of invert sugar or glucose are to be 
 determined within a few per cent of their value, which 
 is usually all that is required in commercial work, but 
 in general can hardly be depended on for more accurate 
 work. When greater precision is required, the gravi- 
 metric methods are necessary. 
 
 1 One of the most promising of these is the Soldani method as developed 
 by Ost (er. d. chem. Ges., 23, 1035, 33 5 2 4 l &34'> Zeits. anal Cheni., 
 29, 637). The solution used is one of copper carbonate in potassium carbo- 
 nates. I have had no experience with this method. 
 
1 66 CHEMICAL METHODS OF DETERMINING SUGARS 
 
 Gravimetric Fehling Methods. These are numerous, 
 but the same general principles prevail in all of them. 
 The Fehling solution, or its modification, is present in 
 excess. The cuprous oxide precipitated during a given 
 period of heating, and under, as nearly as possible, fixed 
 conditions of relation between the sugar, copper solution, 
 and dilution, is taken as a measure of the amount of sugar 
 present. The reduction is carried on by direct boiling or 
 by more prolonged heating on a water bath. The copper 
 is determined, either as cuprous oxide, cupric oxide, or 
 reduced by hydrogen to the metal, it being a matter of 
 indifference which, provided the proper procedure is fol- 
 lowed. In some cases the washed precipitate is dissolved 
 in nitric acid and the copper determined electrolytically or 
 volumetrically by the usual methods. One way is to dis- 
 solve the washed cuprous oxide in a standard solution of 
 ferric sulphate, and determine the ferrous salt formed by 
 standard permanganate solution. Many prefer to use cop- 
 per solutions containing more alkali than the Soxhlet solu- 
 tion contains. Such solutions have greater sensitiveness 
 to reduction, but reduce to a slight extent spontaneously, 
 so that blank corrections must be made. 
 
 Whatever the method chosen, the time and conditions of 
 the heating, as well as the concentration of the Fehling liquor 
 and the extent of surface of the hot solution exposed to the 
 air, must be uniform in all tests. As in the volumetric 
 processes, these conditions are vital to accuracy. 
 
 Usually the cold sugar solution is added to the Fehling 
 liquor after the latter has been heated to the temperature 
 at which the reduction is carried on. The length of time 
 taken to add the sugar solution and the conditions of 
 
CHEMICAL METHODS OF DETERMINING SUGARS l6/ 
 
 admixture of the two solutions have considerable influence 
 on the reduction, especially where the heating is done on a 
 water bath. 
 
 As illustrative of a standard gravimetric method carried 
 out by direct boiling, the following is that of Herzfeld for 
 determining invert sugar : 
 
 The solution in which invert sugar is to be determined 
 is made up so that 100 cubic centimeters contain 20 grams 
 of sample, after clarification with basic lead acetate and 
 removal of the soluble lead in the filtrate by sodium car- 
 bonate. 1 The German way of doing this is to dissolve 
 2 7- 5 grams of sample in 125 cubic centimeters, the solu- 
 tion being made up with basic lead acetate, as for polariz- 
 ing, and filtered; 100 cubic centimeters of the filtrate are 
 put into a loo-uo-cubic-centimeter double-marked flask, 
 and 10 cubic centimeters of sodium carbonate added, the 
 solution after mixing being again filtered. 
 
 1. If the sample has been shown to contain less than 
 i per cent of invert sugar (by a rough volumetric test, 
 20 cubic centimeters failing to decolorize 12 cubic centi- 
 meters of the Fehling solution by 2 minutes' boiling), 50 
 cubic centimeters are taken for the exact gravimetric test. 
 
 2. If the sample is shown to contain more than i per 
 cent of invert sugar, the solution containing 20 grams of 
 sample in 100 cubic centimeters must be diluted to corre- 
 spond to one made from a sample containing i per cent 
 of invert sugar. This dilution is determined with sufficient 
 exactness by preparing in large test tubes dilute solutions 
 containing respectively i, 2, 3, 4, and 5 cubic centimeters 
 
 1 Potassium oxalate is preferred by some (Sawyer,/. Am. Chem. Soc. y 26, 
 1631). 
 
1 68 CHEMICAL METHODS OF DETERMINING SUGARS 
 
 of the 20-gram solution, adding 5 cubic centimeters of 
 Fehling solution, and boiling two minutes. The tube show- 
 ing a solution which (after the copper precipitate has been 
 removed by subsidence or filtration) is still blue but lightest 
 in tint is noted, and twenty times the number of cubic centi- 
 meters of original solution contained in this tube is dis- 
 solved in 100 cubic centimeters. Of this final solution, 
 50 cubic centimeters is used as before, for the exact 
 gravimetric test, which is as follows : 
 
 Fifty cubic centimeters of the sugar solution are mixed 
 with 25 cubic centimeters each of the two constituent solu- 
 tions of the Fehling liquor, in a 25o-cubic-centimeter beaker, 
 and the whole heated on a wire netting on which is laid a 
 sheet of asbestos paper having a circular hole cut in it 6.5 
 centimeters in diameter. The flame of the burner is so 
 regulated that it takes 3^ to 4 minutes to bring the con- 
 tents of the beaker to a boil. Then the boiling is con- 
 tinued 3 minutes exactly, when the beaker is immediately 
 cooled by the addition of 100 cubic centimeters of cold dis- 
 tilled water. Evidently all the conditions for a constant 
 factor of reduction exist in this method except the inevi- 
 tably variable proportion of sugar to the copper solution ; 
 but, as this variable is measured by the amount of cuprous 
 oxide precipitated, a table has been devised by Herzfeld 
 giving the equivalent of sugar for the weight of copper 
 obtained. Herzfeld has made his tables for invert sugar 
 determination and determined the reduction by the amount 
 of copper actually obtained by reduction from the oxide. 1 
 The precipitate is collected in a "Soxhlet tube," a long, 
 straight funnel tube packed at the lower end with asbestos 
 
 1 See Appendix, Tables Nos. 7 and 8. 
 
CHEMICAL METHODS OF DETERMINING SUGARS 169 
 
 held in place with a platinum sieve. The tube is placed 
 on a suction flask and the Fehling liquor with the precipi- 
 tated cuprous oxide poured into it through an ordinary 
 funnel attached by means of a stopper. After the precipi- 
 tate is collected and quickly washed with 
 hot water, it is attached to a hydrogen 
 generator and the oxide heated to glow- 
 ing while the gas is passing. This 
 quickly reduces the oxide to the metallic 
 state. The tube is then placed in a 
 
 desiccator and, after cooling and coming FIG. 29. SOXHLET 
 
 . , -TT- '-LU ^ i. TUBE WITH FUN- 
 
 into equilibrium with the atmosphere, NEJ ATTACHEDt 
 
 is weighed. Special platinum dishes 
 equipped with tubulated covers have been devised in 
 which the cuprous oxide, collected on a filter paper in 
 the ordinary way, can be reduced and more conveniently 
 weighed. Sometimes the cuprous oxide is weighed directly 
 by washing in a Gooch crucible, and then adding 10 cubic 
 centimeters of alcohol and afterward 10 cubic centimeters 
 of ether, then drying at 100 C. for half an hour. 
 
 Another way is to heat the cuprous oxide, collected in a 
 Gooch crucible, to redness for fifteen or twenty minutes. 
 This converts it into the cupric oxide, which is more stable 
 than the cuprous. Cupric oxide is, however, very hygro- 
 scopic, and requires special care in handling, to avoid error 
 from moisture. Obviously it is immaterial whether the re- 
 duction tables are figured in weights of copper or copper 
 oxide, as the values are convertible by the appropriate 
 factors. 
 
 The method of Defren, 1 adapted from O'Sullivan, can be 
 
 1 J. Am. Chem. Soc,, 1896, 18, 749. Tech. Quart., 1897, IO > I ^7 
 
I/O CHEMICAL METHODS OF DETERMINING SUGARS 
 
 taken as illustrating the conduct of the test by heating on 
 the water bath. In this method 15 cubic centimeters each 
 of the white and blue solutions of the Fehling liquor are 
 taken in a loo-cubic-centimeter Erlenmeyer flask, propor- 
 tioned so that its base diameter is between one third and 
 one half of its height. The Fehling liquor is diluted with 
 50 cubic centimeters of water, and heated by immersion in 
 the water for 5 minutes, in order to come to the bath tem- 
 perature. Then 25 cubic centimeters of the sugar solution 
 are run in and thoroughly mixed, and the solution heated for 
 exactly 12 minutes in the water bath. 
 
 The precipitate is then filtered off into a porcelain 1 
 Gooch crucible, having an asbestos mat about one centi- 
 meter thick, ignited, and weighed as the cupric oxide. 
 Great care must be taken in the preparation of the asbes- 
 tos used in these filters. It must be thoroughly boiled in 
 i.io nitric acid, thoroughly washed, and then boiled with a 
 10 per cent solution of caustic soda and washed. It is 
 sometimes advisable to repeat this treatment with acid and 
 alkali. The crucible, after preparation of the asbestos 
 mat, is ignited to constant weight. 
 
 The following procedure is advisable in working with 
 porcelain Gooch crucibles, to prevent their cracking : The 
 crucible, after removing from the filter flask, is placed 
 on a "radiator," a heavy, hollow, cast-iron cone, about 
 7 centimeters in diameter, in the open base of which 
 is a platinum wire triangle for holding the crucible. When 
 this inverted cone is heated over a burner, it gives out a 
 moderate, even heat, which will not crack the crucible, 
 even if it is immediately removed from the filter flask. 
 
 1 Platinum crucibles can be used to advantage. 
 
CHEMICAL METHODS OF DETERMINING SUGARS 1 71 
 
 After a few minutes, the hot, dry crucible is transferred to 
 a large nickel or platinum crucible, heated to a bright red, 
 where the ignition is completed. 
 
 As already stated, the manner of applying the sugar 
 solution has an important influence on the result. Defren's 
 tables were calculated for a reduction taking place when 
 the solution was added from a burette to the flask previ- 
 ously removed from the bath. Slight variations in this 
 part of the procedure, in the time taken to add the solu- 
 tion, the cooling caused by the admixture, and the stirring, 
 are all liable to make variations in the amount of total 
 reduction. 
 
 In fact, whatever the Fehling method employed, inas- 
 much as very slight changes in the manipulation, not 
 covered by tne details of the description of the method, 
 often affect the reduction factors materially, in accurate 
 work the analyst should cultivate as uniform a habit of 
 procedure as possible, even in minor details of manipula- 
 tion, and carefully check his work by standard sugar solu- 
 tions of known value, until his determinations give results 
 in accord with the tabulated values given by that method, 
 or should determine the values for his own work. This 
 is imperative in cases of investigations of hydrolyzed starch 
 products, for instance, where slight variations in the reduc- 
 ing value are significant ; but in the case of the determina- 
 tion of invert sugar in cane or beet sugar liquors, where 
 the invert sugar content is small, an error of a few per 
 cent of the actual value obtained is often insignificant, 
 and consequently does not call for such refinement. 
 
 Blank Fehling tests should always be made with new 
 Fehling solution, carrying out every condition of the 
 
1/2 CHEMICAL METHODS OF DETERMINING SUGARS 
 
 regular sugar determination, for although with the Soxhlet 
 solution no reduction should take place, sometimes such 
 Periling liquors do show " spontaneous reduction," espe- 
 cially if the Rochelle salt is of inferior quality. 1 In the 
 case of the investigation of certain products, where the re- 
 duction is small, and the amount of impurity, such as lime 
 or lead, is large, this must be removed before making the 
 test. In some such cases it will be better, obviously, to 
 dissolve the cuprous oxide in nitric acid, and determine it 
 electrolytically. The intelligent worker will modify his 
 method according to circumstances. The dilution of his 
 sugar solution should be taken so as to have at least .1 
 gram of precipitated oxide. 
 
 Cupric Reducing Power. In the identification of the 
 different sugars and starch products, it is often convenient 
 to calculate the reduction as a value of the pure substance 
 referred to the reduction value of an equivalent weight of 
 dextrose taken as i.oo. This is known as the "cupric re- 
 ducing power " of the substance, and symbolized by the 
 Greek letter /c. For instance, the cupric reducing power 
 of maltose is .62, that of invert sugar [95, etc., which means 
 that maltose reduces .62 as much copper solution as the 
 same weight of dextrose under the same conditions of test ; 
 invert sugar, .95 as much. 
 
 Under different conditions of reduction prevailing in 
 different methods, the cupric reducing powers of different 
 sugars do not give the same constant value. 
 
 1 Blank tests also show whether all soluble matter has been removed from 
 the asbestos by the chemical treatment described. The crucible should show 
 no change in weight. 
 
STARCH AND STARCH PRODUCTS 
 
 Chemistry of Starch. Starch is vital to higher plant 
 life, and while widely distributed in vegetable tissue, espe- 
 cially makes up a large part of the substance of many 
 grains and tubers. As found in nature, it is in the form of 
 minute granules, of a density of 1.6, the shapes of which 
 vary much in starches from different plants, but are so 
 characteristic that investigation with the microscope will, 
 in most cases, easily determine their botanic origin. While 
 authorities differ as to the exact structure of the starch 
 granule, from the standpoint of the chemist it may be con- 
 sidered as composed of a mass of carbohydrate paste, 
 inclosed in denser tissue of apparently the same general 
 chemical composition, known as "starch cellulose." 
 
 The unbroken starch granule is insoluble in cold water, 
 but if a mixture of starch and water is heated to about 70, 
 the exact point differing with different starches, the starch 
 suddenly swells to a pasty jelly. The microscope shows 
 that this is the result of the expanding of the interior con- 
 tents by absorption of water till the enveloping tissue of 
 starch cellulose has been ruptured, the greatly swollen 
 jelly contents escaping. 
 
 If the cell structure is ruptured mechanically by grind- 
 ing starch with sharp quartz sand, or the " cellulose " 
 removed chemically by dilute solutions of alkalies, zinc 
 
1/4 STARCH AND STARCH PRODUCTS 
 
 chloride, or other solvents, the same thing occurs. At the 
 same proportions of starch arid water, the consistency of 
 pastes made from starches of different origin differs much, 
 and, in consequence, starches have been placed in two 
 classes, "thick boiling" and "thin boiling." It is now 
 known that the conditions of the process by which the 
 starch has been extracted from the plant have much to do 
 with this pasting property. 
 
 Chemically classified, it has been shown by Brown and 
 Millar that starch paste is a highly condensed hexose car- 
 bohydrate of the formula, 100 C 6 H 10 O 5 , which can be con- 
 sidered as an aggregation of 100 anhydride groups derived 
 from dextrose by the removal of as many equivalents of 
 water. As would be expected, such a complicated body 
 is easily resolved by hydrolytic agents into simpler com- 
 binations, finally becoming dextrose, a result which can 
 practically be attained by prolonged acid hydrolysis. 
 
 If the hydrolysis with acid is followed from the be- 
 ginning, there is found to occur a gradual disintegra- 
 tion of the starch into products which chemically can 
 be considered as molecular aggregations of three well- 
 defined compounds, maltose (C 12 H 22 O n ), a dextrin 
 (C 6 H 12 O 6 (C 6 H 10 O 5 ) 39 ), and dextrose (C 6 H 12 O 6 ). 
 
 If an ensym is used as the hydrolytic agent, such as 
 diastase, which is the active principle of malt, the hydroly- 
 sis under ordinary conditions does not go on till dextrose 
 is the final product, but the compounds formed are aggre- 
 gates of maltose and dextrin only. The hydrolysis under 
 different temperature conditions of the diastase action 
 has been found to follow well-defined reactions. The one 
 occurring at 45 C., and most favorable for the production 
 
STARCH AND STARCH PRODUCTS 1 7$ 
 
 of the greatest amount of maltose, can be expressed by the 
 following reaction : 
 
 100 C 12 H 20 10 + 8 1 H 2 = 80 C 12 H 22 O n 
 
 + (C 6 H 10 O 5 ) 39 C 6 H 12 O 6 , 
 
 action ceasing when these compounds have been formed 
 in the proportions given by the equation, and the solution 
 coming into chemical equilibrium. 
 
 In acid hydrolysis there is a progressive decrease in the 
 dextrin constituent as the action continues, and a similar 
 increase in the amount of the dextrose which is formed in 
 this hydrolysis. The maltose at first increases rapidly, but, 
 after reaching a maximum of about 45 per cent of the total 
 carbohydrate, diminishes as rapidly, till, at the completion 
 of hydrolysis, it is entirely converted into dextrose. At no 
 point in the hydrolysis, except at the very beginning and 
 end, are any of these constituent carbohydrates entirely 
 absent. The gradual disintegration of the starch molecule 
 and the different stages of the hydrolysis of the products 
 of this disintegration all go on at the same time, so that 
 the final products of hydrolysis are always present in very 
 small quantity even at the initial stages of the hydrolysis. 
 
 The progression of the hydrolysis manifests itself in the 
 following characteristics : The starch paste gradually loses 
 its colloidal nature and passes over to a thin sirup, its 
 viscosity continually decreasing. The dissolved carbohy- 
 drate increases in weight, but the density, proportionally, 
 continually decreases, that is to say, the density effect 
 of a given weight of carbohydrate in a given volume of 
 solution continually decreases. The specific rotation of 
 the carbohydrate, taken as a whole, likewise decreases, 
 
1/6 STARCH AND STARCH PRODUCTS 
 
 while its cupric-reducing power increases, these values 
 progressively approaching those for dextrose. 
 
 The iodine tests are also characteristic ; a few drops of 
 iodine solution giving, with the hydrolyzed solutions, at 
 ordinary temperature, colors which change progressively 
 as the hydrolysis proceeds, from the deep sapphire blue of 
 the unchanged starch, first to violet and reddish purple, then 
 to a rose madder, and then to a reddish brown, growing 
 lighter as the conversion proceeds, till at a later stage, but 
 before hydrolysis is complete, the iodine gives no color 
 reaction. 
 
 These colors are so characteristic that an expert can 
 follow the progress of the hydrolysis with considerable 
 precision. In commercial hydrolytic processes, as the 
 manufacture of " commercial glucose," they are depended 
 on to define the requisite point of " conversion." 
 
 By precipitation with alcohol, numerous well-defined 
 compounds, known as "dextrins," can be separated from 
 hydrolyzed starch products, which give colorations with 
 iodine corresponding to the degree of hydrolysis of the 
 starch solution from which they were obtained. These 
 products behave, however, chemically and optically, as if 
 they were mixtures of maltose, dextrose, and the primary 
 constituent dextrin already alluded to, so they need not be 
 considered here. Other reactions of starch will be referred 
 to only when necessary for explanation of the subject at 
 hand. 
 
 Commercial Starch. Although starch is so widely dis- 
 tributed in Vegetable tissue, constituting a large proportion 
 of our food products, comparatively few plants are utilized 
 in making the commercial product. Among these, by far 
 
STARCH AND STARCH PRODUCTS 177 
 
 the most important in this country is Indian corn (maize). 
 In Europe, starch is made almost exclusively from potatoes ; 
 some potato starch is made in this country also. Wheat 
 starch is likewise of commercial importance, the starch 
 being manufactured from flour. Tapioca and rice starches 
 are made in the far East, and brought to this country, the 
 former being a recent product of Florida from the cassava 
 root. 
 
 The general methods of starch manufacture naturally 
 fall into two classes: (i) those in which the albuminous 
 by-products (gluten) are saved and utilized ; (2) processes 
 where the gluten is decomposed by fermentation or chemi- 
 cal methods. 
 
 Originally, the gluten was removed entirely by fermen- 
 tation and lost, but by modern methods most of this is 
 now saved and utilized in various ways. The ferment 
 acids arising from the destruction of the gluten by the 
 older processes always produced an incipient hydrolysis 
 which made the starch to a greater or less degree "thin 
 boiling." 
 
 The general principles of process of making commercial 
 starches are as follows : ( i ) Breaking down the plant tissue 
 in such a way that the starch grains are set free but not 
 ruptured. (2) Separation from the gluten, usually by dilut- 
 ing the mixture of starch and gluten with a large amount of 
 water, and then settling out the heavy starch by subsidence 
 in tanks or by flowing the diluted mixture down long, very 
 slightly inclined canals ("runs") in which the starch is 
 deposited. (3) Washing the starch by agitating with water 
 in tanks. (4) Draining off the starch from the starch 
 " milk " in cloth-bottom edNf draining boxes " or in filter 
 
178 STARCH AND STARCH PRODUCTS 
 
 presses of special design. (5) Drying the starch in hot 
 rooms ("kilns"). 
 
 Grains have to be steeped in warm water for several 
 days before they can be ground. In the case of wheat 
 starch, the gluten of which is thick and rubbery, balls 
 of dough prepared from flour are worked in a special 
 kneading machine, the starch being washed out during 
 the kneading by jets of water. 
 
 As already stated, starches derived from different plants 
 vary considerably in the thickness ("body") of the pastes 
 they make when mixed with hot water, some being quite 
 liquid, others, at the same concentration, being too dense 
 to flow. It has been found that this quality of the starch 
 depends largely on the amount of hydrolytic change to 
 which the starch has been subjected in the necessary detail 
 of process. Consequently, manufacturers have learned to 
 control this pasting property to a considerable extent, so 
 that products can be made to suit the special requirements 
 of the customer. 
 
 The manufacture of corn starch is by far the most im- 
 portant branch of the industry, and in no other has the 
 utilization of by-products and the development of manu- 
 factures derived from starch been carried so far. 
 
 As corn starch is made in conjunction with glucose 
 and grape sugar, special reference will be made to this 
 later. 
 
 Methods of determining Starch. Numerous methods 
 have been proposed for the determination of starch, espe- 
 cially in grains and foods prepared from grains. Most of 
 them depend on the following principles, it being advisable 
 and in some cases necessary to dry the sample and remove 
 
STARCH AND STARCH PRODUCTS 179 
 
 the fats, and of course essential in every case that the sam- 
 ple be ground to the greatest possible fineness, and that all 
 other carbohydrates which are soluble in water or alcohol, 
 such as sugars, gums, and dextrins, be previously extracted : 
 (i) Dissolving out the starch by hydrolyzing with malt 
 extract, and determining the starch by difference. (2) Com- 
 pletely hydrolyzing the starch with hydrochloric acid, and 
 determining the dextrose formed by the Fehling method. 
 (3) Dissolving and filtering off the starch as in (i), then 
 completing the hydrolysis with acid and determining the 
 dextrose. (4) Same as (3), except that starch is dissolved 
 by heating with water under steam pressure of about 
 three atmospheres, by means of an autoclave. (5) Partially 
 hydrolyzing with salicylic or nitric acid, and polarizing the 
 solution. (6) Determining the amount of standard barium 
 hydrate, which will combine with the pasted starch. None 
 of these methods are very satisfactory, although most of 
 them are accurate with/z/;r starch. 
 
 The solution method, in which the starch is determined 
 by difference, assumes that starch (from which the water- 
 soluble carbohydrates have been removed) alone is dis- 
 solved out by malt extract, but it is known that some of 
 the proteid matter is also dissolved. 
 
 With the acid-hydrolysis method, in the case of grains 
 particularly, other carbohydrates which are present, espe- 
 cially "pentosans," carbohydrates containing five equiva- 
 lents of carbon, of the general formula (C 5 H 8 O 4 ) W , analogues 
 of starch, are hydrolyzed into pentose sugars, which also 
 reduce Fehling solution, and so introduce error. 
 
 The polariscope methods are unsatisfactory, owing to the 
 difficulty in getting clear solutions and the large amount 
 
I So STARCH AND STARCH PRODUCTS 
 
 of substance required. The barium method is of doubtful 
 reliability, except with very pure starches. The methods 
 following the principles given in (3), in which the starch is 
 partially converted by malt extract, and separated from the 
 other substance previous to completing the conversion to 
 dextrose, are considered the most reliable, as experimental 
 evidence tends to show that pentosans are unaffected by 
 diastase, which is the active enzym of malt. 
 
 When pentosans are absent, the method of Sachsse by 
 simple acid hydrolysis is the standard, and is as follows : 
 An amount of dry substance containing 2.5-3 grams of 
 starch is heated on a boiling-water bath with 20 cubic 
 centimeters of hydrochloric acid, of a density of 1.125 
 (the ordinary " dilute " reagent), and 200 cubic centimeters 
 of water, in a flask with an air condenser (a long, straight 
 glass tube passed through the stopper) for three hours ; 
 or the flask is fitted with a return Liebig condenser, or 
 one of similar type, and kept boiling by a direct flame for 
 one hour and a half. The contents of the flask, after 
 cooling, are then neutralized with sodium hydrate, care 
 being taken not to get it alkaline (very faint acidity does 
 no harm), made up to 500 cubic centimeters, and the dex- 
 trose determined by Fehling solution. By the simple 
 formula, C 12 H. 20 O 10 + 2 H 2 O = 2 C 6 H 12 O 6 , the equivalent 
 of starch is .9 the amount of dextrose. Experiment has 
 shown that there is always a certain amount of decomposi- 
 tion in the complete hydrolysis of starch to dextrose, so 
 that the factor .92, according to Wiley and Krug, gives 
 more accurate results. 
 
 The diastase method, according to Wiley, 1 being practi- 
 
 1 Agric. Chem. Anal., 3, 198. 
 
STARCH AND STARCH PRODUCTS l8l 
 
 cally the Halle (Agricultural Station) method, is as follows: 
 About 3 grams of the finely pulverized material is ex- 
 tracted, first with ether, and then with 10 per cent alcohol, 
 and boiled with 100 cubic centimeters of water for 30 
 minutes with constant stirring, to set free the starch paste. 
 The water lost by evaporation is replaced, and the mix- 
 ture placed in a water bath at 55-60 C. When the liquid 
 las cooled to the water-bath temperature, 10 cubic centi- 
 meters of fresh malt extract are added, and the whole is 
 digested for an hour with occasional stirring. The mix- 
 ture is then digested for 15 minutes with another 10 cubic 
 centimeters of malt extract. This treatment is again 
 repeated. The mixture is then filtered, made up to 250 
 cubic centimeters, and 200 cubic centimeters is hydrolyzed 
 according to the Sachsse method, two hours being sufficient 
 for the acid hydrolysis on the water bath. The malt extract 
 is made by soaking 100 grams of fresh malt in 100 cubic 
 centimeters of cold water for two or three hours, and filter- 
 ing ; or, as recommended by Wiley for a more permanent 
 extract, 1000 grams of finely ground "green" (not kiln- 
 dried) malt is mixed with a liter of glycerine and allowed 
 to stand for eight days with frequent shaking. It is then 
 filtered under pressure, and again by ordinary filtration. 
 This extract is said to keep well. 
 
 As malt extracts always contain some reducing sugars, 
 blank Fehling tests must be made to determine the neces- 
 sary correction to be applied. Hibbard's modification of 
 the diastase method for rapid work is as follows : Previous 
 extraction with ether is omitted. Enough of the mixture 
 to contain at least .5 gram of starch is placed in a flask 
 with 50 cubic centimeters of water and about 2 cubic 
 
1 82 STARCH AND STARCH PRODUCTS 
 
 centimeters of malt extract, and heated to boiling with 
 frequent shaking to prevent pasting. The mixture is 
 boiled one minute, cooled to 60 C, and 2 or 3 cubic, 
 centimeters of malt extract again added. It is then 
 heated gradually to boiling, taking 15 minutes, cooled, 
 and tested with iodine for any unchanged starch. If 
 starch is shown, the operation must be repeated. The 
 rest of the procedure is as in the method previously 
 described. 
 
 In any method where diastase is used as a solvent, the 
 residue from the filtrate of the malt-converted liquor should 
 be examined for unconverted starch. 
 
 Wiley recommends the use of pepsin in conjunction with 
 malt extract as a solvent of the proteid matter which in- 
 closes the starch granules and interferes with the solution 
 of the latter. 
 
 Optical and Reducing Properties of Hydrolyzed Starch 
 Products. It is impossible to polarize pure starch, as it 
 forms a colloidal solution which is practically opaque, 
 except in very dilute solutions ; the liquid solutions of some 
 starches, so called, being really of starch which has under- 
 gone an incipient hydrolysis in the process of extraction 
 from the plant tissues, or in the treatment for polarizing. 
 Pure starch can be shown theoretically to have a specific 
 rotation of about 202. It gives no reduction with Fehling 
 solution. If starch is hydrolyzed with acids, there is a 
 regular decrease in the rotation, and a reducing power is 
 developed which shows a corresponding increase as the 
 rotatory power decreases, till the specific rotation becomes 
 practically constant at 52.7 and the cupric-reducing power 
 becomes i.oo. If the heating is prolonged and the hydrolyz- 
 
STARCH AND STARCH PRODUCTS 183 
 
 ing acid of considerable strength, these exact figures are 
 not obtained, owing to a small amount of decomposition 
 products which is formed. 
 
 Investigations made in the laboratory of the Massa- 
 chusetts Institute of Technology 1 have shown that a defi- 
 nite relation exists between the specific rotation and the 
 cupric-reducing power of acid-hydrolyzed starch products 
 at every stage of conversion; in other words, strong ex- 
 perimental evidence tends to prove that the cupric-reduc- 
 ing power of any normally acid-hydrolyzed starch product 
 can be predicted, if its specific rotation is known. The 
 relation of the cupric-reducing power plotted from actual 
 experimental results shows a curve which cuts the o and 
 i.oo points, expressing the cupric-reducing values, very 
 nearly at rotations of 202 and 52.7 respectively. 2 This 
 means that all acid-hydrolyzed products of the same spe- 
 cific rotation have the same composition, and consequently, 
 the determination of specific rotation is a rapid means of 
 identifying such (pure) products. A similar law of rela- 
 tion has been proved by Brown and Morris to exist in all 
 diastase-hydrolyzed starch products. In this latter case, 
 the law of relation is represented in plot by a straight line, 
 the cupric-reducing values of o and .62 being at points of 
 specific rotation of 203 and 138 respectively; the value 
 .62 is the cupric-reducing power and 138 the specific rota- 
 tion of pure maltose, which is the final product present in 
 malt (diastase) converted starch. 
 
 1 J. Am. Chem. Soc., 18, 869; ibid., 25, 1003. Wiley pointed out a simi- 
 lar relation in the case of commercial glucose as early as 1882 (Proc. A. A. 
 A. S., 30, 65). 
 
 2 See diagram on page 198. 
 
1 84 STARCH AND STARCH PRODUCTS 
 
 Methods of Analysis of Acid-hydrolyzed Starch Products. 
 As already stated, acid-hydrolyzed starch products can 
 be considered to be composed of three primary constitu- 
 ents, dextrose, maltose, and dextrin. These constituent 
 bodies cannot be isolated from each other except by a 
 tedious and complicated procedure impracticable for most 
 commercial analysis. In consequence, an ingenious indi- 
 rect method has been worked out by which the proportions 
 of the primary constituents are calculated from the results 
 of three determinations, the total solids, the specific rota- 
 tion, and the cupric-reduciug power. The acid-hydrolyzed 
 product being pure, evidently, if the per cents of dextrose, 
 dextrin, and maltose are expressed (as decimals) by D, A, 
 and ;;/ respectively, the composition of the carbohydrate sub- 
 stance will be expressed by the following equation : 
 
 D + m + A = i. (i) 
 
 As the specific rotatory power of dextrose is 52.7, that 
 of maltose 138, and dextrin 203, the specific rotatory 
 power of the hydrolyzed product is given by the following : 
 
 52.7 D + 138 m + 203 A = a/,. (2) 
 
 Two of the constituents, dextrose and maltose, give re- 
 duction by the Fehling method, maltose having .62 the 
 reducing power of dextrose. This stable dextrin is 
 usually considered to be non-reducing (although the re- 
 searches of Brown and Millar 1 have recently shown that 
 the corresponding and probably identical dextrin of dias- 
 tase conversion has a cupric-reducing power of about .03). 
 
 1 y. Chem. Soc., 75, 322. 
 
STARCH AND STARCH PRODUCTS 185 
 
 The following equation would then express the cupric- 
 reducing power of the acid hydrolyzed product : 
 
 K = D + .62 m. (3) 
 
 From the three independent equations, the values of /?, 
 m, and A can be determined. 
 
 Total Solids. In order to determine the optical and 
 reducing constants, it is necessary to know the exact 
 amount of pure carbohydrate in the solution analyzed. 
 As the amount of organic matter, other than carbohydrate, 
 in starch products is, as a rule, negligible, the total solids, 
 -less the mineral matter, which can be determined as ash, 
 represent the total products of hydrolysis. 
 
 As already stated, it is practically impossible to deter- 
 mine the total solids of a saccharine solution with any 
 accuracy by the ordinary methods of drying, and in fact 
 no reliable method at all was known till comparatively 
 recently. On this account, it had become customary for 
 glucose and brewery chemists to use the density of the 
 solution as a measure of the amount of dissolved carbo- 
 hydrate, it being assumed that the density influence of the 
 carbohydrate constituents is identical with that of cane 
 sugar; that is, if the solution has an approximate concen- 
 tration of 10 per cent, every gram of carbohydrate present 
 in 100 cubic centimeters of solution at 15.5 C. increases the 
 density (referred to water at 1 5.5 C.) by .00386. The solu- 
 tions must approximate 10 per cent, as both the density fac- 
 tor and specific rotatory power vary with the concentration. 
 
 By this method, first introduced by O'Sullivan in I8/6, 1 
 the amount of total solids of a solution of pure carbo- 
 
 1 O'Sullivan's original factor was .00385, it being subsequently changed by 
 Brown and Heron to .00386. 
 
1 86 STARCH AND STARCH PRODUCTS 
 
 hydrates resulting from starch hydrolysis was assumed 
 
 to be given by the formula, w = ~~ l ' O(: , this equation 
 
 .00380 
 
 being correct for 10 per cent solutions of cane sugar, within 
 about .1 per cent. If mineral matter be present, as it 
 usually is in small amount, .008 for every gram of ash 
 obtained from 100 cubic centimeters of the solution must 
 first be deducted from the density actually obtained in order 
 to determine the density due to the carbohydrate alone. 
 The density is determined most accurately by the " pyk- 
 nometer," although the " Westphal balance" is sufficiently 
 accurate in careful hands for most work. In commercial 
 analyses in general factory control, the Brix spindle can be 
 used, this giving the per cent of total solids directly without 
 calculation, except for the mineral matter present, which 
 must be corrected for. 
 
 Determination of Density. 1 The Westphal Balance. 
 The essential parts of this apparatus are a glass hydrometer 
 sinker counterpoised on a delicate balance. The weights 
 are in the form of riders, which are designed to be hung 
 on the balance arm which carries the sinker, the other arm 
 serving to carry the fixed counterpoise weight (K) which 
 balances the sinker in air. The weighing arm (H) is gradu- 
 ated into tenths by deep notches cut in the beam, each notch 
 being numbered according to the number of tenths of the 
 distance from the center to the end knife-edge it represents. 
 The largest rider weight hung on the stirrup hook (E) just 
 balances the buoyancy of the sinker when it is immersed 
 
 1 The term " density " is used throughout this book as synonymous with 
 " specific gravity." Both values are, of course, identical for practical labora- 
 tory work. 
 
1 88 STARCH AND STARCH PRODUCTS 
 
 in water at the standard temperature, usually 15.5 C. The 
 glass sinkers are commonly made so that they displace 
 exactly 5 grams of water at the standard temperature, and 
 with the platinum suspending wire and hook weigh exactly 
 10 grams, so that they are interchangeable. In most types 
 a thermometer is inclosed in the sinker. 
 
 The other rider weights are decimals of the largest, 
 weighing respectively .5, .05, .005 grams, each rider 
 being readily distinguished by its size. As a large rider (A), 
 placed on the stirrup hook, just balances the buoyancy of 
 the water displaced by the sinker at standard temperature, 
 showing a density of i.oooo, evidently the sinker immersed 
 in a liquid of a density of i.iooo will be balanced by the 
 addition of the .5-gram rider oh the stirrup hook, an in- 
 crease of .01 in the density requiring the .O5-gram rider 
 to be placed on the stirrup hook, and so on. So, too, it 
 will be clear that the 5-gram rider in any notch on the beam 
 represented by the number of its graduation, ;/, will balance 
 the buoyancy of the liquid caused by any increase in den- 
 sity corresponding to .1 ;/, the .5-gram rider (B) any incre- 
 ment in density corresponding to .01 , etc. For instance, 
 if the balance is in equilibrium when the sinker is immersed 
 in a liquid at 15.5, and one 5-gram rider is on the stirrup 
 hook, another 5-gram rider in the beam notch marked i, 
 the .5-gram rider in notch marked 4, the .O5-gram rider (C) 
 in notch marked 6, and the .oo5-rider (not shown in cut) in 
 notch numbered 8, the density of the solution is 1.1468. 
 Thus, by noting the numbered position of each rider on the 
 beam, and its size, tJie density can be read off directly with- 
 out calculation. (See other illustrations of readings in 
 Figure 30.) 
 
STARCH AND STARCH PRODUCTS 189 
 
 In using the Westphal balance, the sinker (5) is first care- 
 fully balanced in air, by adjusting the leveling screw (G) in 
 the balance foot. The sinker is then immersed in the liquid, 
 care being taken to remove any adhering air bubbles - 
 most conveniently by means of a fine wire. Care should 
 be taken also to have always the same length of support- 
 ing wire of the sinker immersed in the liquid; just how 
 much being determined once for all by calibrating the 
 balance with pure water at the standard temperature, and 
 marking a line on the adjustable supporting post (L) of the 
 balance, and another on the glass cylinder used to contain 
 the liquid. This latter mark will show the height that the 
 cylinder must always be filled to give the proper im- 
 mersion of the wire when the height of the balance is 
 adjusted to the mark on the post by the set screw P. 
 The Sartorius type of Westphal is so marked by the 
 maker. 
 
 A well-made Westphal balance should be precise to 
 .0005 gram, and consequently should have the same care 
 as any other analytical balance. 
 
 Determination of Density by the Pyknometer. This is 
 the most precise method. There are many forms of pyk- 
 nometers, but most of the ordinary types used for determi- 
 nations of densities by weighing 20 cubic centimeters or 
 more of solution are practically identical in principle, 
 light flasks which are devised so that they can be accurately 
 filled to a fixed volume within an error represented by the 
 difference in weight of about .001 gram, the point of level 
 of the liquid filling the pyknometer being read off in a 
 capillary tube. Usually there is a thermometer attached, 
 and a tightly fitting cap for the capillary tube, so as to 
 
190 STARCH AND STARCH PRODUCTS 
 
 retain any water expanding out of the flask during 
 weighing. 
 
 The method of using the pyknometer is as follows: 
 The weight of the carefully cleaned and dried apparatus 
 is taken, or it is balanced with a tare weight. The pyk- 
 nometer is then filled with freshly boiled water at a tempera- 
 ture somewhat lower than the standard, and then allowed 
 to warm up till the thermometer shows that the standard 
 temperature is reached, or, for greater accuracy, brought 
 to the standard temperature by immersion in a cold-water 
 bath. The liquid which has oozed from the capillary is 
 then carefully wiped off, and the opening closed with the 
 glass cap (or in some forms of pyknometer, the level of the 
 liquid in the capillary is merely brought to a mark). The 
 pyknometer is again weighed. In this manner the weight 
 of water the pyknometer contains at standard temperature 
 is obtained once for all, this expressing the volume in Mohr 
 cubic centimeters. 
 
 The weight of any solution contained by the pyknometer 
 at standard temperature, obtained in the same way, divided 
 by the volume, gives the density relative to its volume in 
 Mohr cubic centimeters. Absolute densities (referred to vol- 
 umes in true cubic centimeters at 20 C.) can be calculated 
 
 by the formula, d~^~= -, where w f is the weight of solu- 
 tion and w the weight of water, both taken at 20, D^ 
 being the density of water at 20. 
 
 As the air buoyancy has practically the same influence 
 on both weights, reduction to vacuo is unnecessary for or- 
 dinary-sized pyknometers. 
 
 A very convenient pyknometer, used by the author in 
 
STARCH AND STARCH PRODUCTS 
 
 \ 
 
 A 
 
 V 
 
 f 
 
 ; 
 
 the laboratory of Professor J. M. Crafts, is shown in the 
 following sketch : 
 
 The pyknometer is designed to be used with a constant 
 temperature bath, the reference point by which the volume 
 is measured being marked on 
 the funnel stem. The method 
 of using is by filling the flask 
 through the funnel tube, and 
 after bringing the contents to 
 the standard temperature by 
 means of the water bath, gently 
 inclining the apparatus so that 
 the liquid dropping out of the 
 capillary sinks to the mark A 
 on the funnel stem. 
 
 The pyknometer can then 
 be placed upright on the bal- 
 ance pan and weighed at con- 
 venience, as there is ample 
 room for the liquid to expand 
 from any change in ordinary 
 laboratory temperature, without spilling out of the pyk- 
 nometer. 
 
 As stated, it is customary in commercial work to deter- 
 mine the constituents of both malt and acid converted 
 starch products, such as beer worts, commercial "glucose," 
 and grape sugar, by determining the carbohydrates from 
 the density by means of the factor .00386. Obviously, the 
 true specific rotatory and cupric-reducing constants are in 
 F 
 
 FIG. 31. DIAGRAM OF CON- 
 VENIENT PYKNOMETER. 
 
 the ratio of 
 
 .00386 
 
 to the values obtained by this method^ 
 
1 92 STARCH AND STARCH PRODUCTS 
 
 where F represents the true density factor of the product 
 examined. If the primary constituents are calculated by 
 the equation already given, the percentages will be practi- 
 cally correct, provided the optical and reducing constants 
 nsed are based on the factor .00386. For instance, the 
 specific rotation of maltose is 138, but as its density factor 
 for a 10 per cent solution is .00393, its specific rotation for 
 the factor .00386 (symbolyzed, [a]^^) is fff x 138, or 
 
 I3S.5 . 
 The equations with these constants become : 
 
 i. (i) 
 
 53.0 />+ 135.5 * + 195 A = a^ 386 . (2) 
 
 Z>+.6i^ = K 386 . (3) 
 
 (The per cents are given as decimals by these equations.) 
 In 1897 Brown, Morris, and Millar published curves 
 giving the density factors of most of the common hexose 
 carbohydrates and starch derivatives of malt conversion, 
 calculated from results obtained by evaporation of solu- 
 tions in vacuo over phosphorus pentoxide. Similar work 
 was done in 1889 on acid-hydrolyzed starch products at 
 the sugar laboratory of the Massachusetts Institute of 
 Technology, so that the true density factors are now well 
 established for pure products of acid and diastase con- 
 verted starch. 
 
 As, however, the density factors differ with the degree of 
 conversion, and as this latter is measured most conveniently 
 and rapidly by the specific rotatory power, it is most con- 
 venient to obtain first this value as expressed by the factor 
 .00386 in calculating the absolute value. 
 
STARCH AND STARCH PRODUCTS 1 93 
 
 Determination of Specific Rotatory Power. The density 
 of the filtered solution of the hydrolyzed product (which 
 should approximate to 1.04) is determined as accurately 
 as possible at 15.5. The solution is then polarized in a 
 2-decimeter tube, most conveniently in a quartz-wedge 
 saccharimeter provided with a yellow light screen, either 
 of bichromate solution or a piece of brown glass. The 
 saccharimeter reading is multiplied by the " light factor " of 
 the instrument for hydrolyzed starch (discussed in a later 
 chapter) which is .345. The saccharimeter reading multi- 
 plied by this coefficient, which is the equivalent of one sac- 
 charimetric division in angular degrees of rotation of the 
 plane of polarization of the standard yellow ray, gives a of 
 the equation : av 
 
 hv 
 
 Since w in 100 (Mohr) cubic centimeters l = .the 
 
 .00386 
 
 equation becomes, a, 386 = '345 ^10^.00386) 
 
 Expressing the constants by a four-place logarithm, the 
 calculation for a/> 386 becomes : 
 
 a = log. /L -f colog. (d i) + 8.823410. 
 
 The density, especially in acid-hydrolyzed products, must 
 be corrected for the influence of the dissolved mineral mat- 
 ter. This is done by taking 20 cubic centimeters of the 
 solution, evaporating practically to dryness in a tared plati- 
 num dish, and then incinerating in a "low temperature" 
 muffle, a little vaseline being added to prevent excessive 
 swelling of the coal. The ash is weighed to .0001 gram, 
 
 1 The density standard is 15.5 C, the polarimetric, 20 C. 
 o 
 
194 STARCH AND STARCH PRODUCTS 
 
 and .008 is deducted from the density for every gram pres- 
 ent in 100 cubic centimeters of the original solution. 
 
 For factory control in the manufacture of glucose, and in 
 commercial work where great accuracy is not needed, the 
 Brix spindle can be used, the reading of which giving per 
 :ent of solids (grams in 100 grams) must be applied in the 
 
 ..ormula, a= , the Brix reading being taken as /; d 
 
 being found from the Brix comparison table. Since the 
 density at which the optical and reducing constants have 
 been calculated is approximately 1.04, it is clear that an 
 error of .1 Brix (about .0004 in density) makes an error of 
 i per cent in the result. Hence the ordinary Brix spindle 
 is not sensitive enough for highest accuracy. In com- 
 mercial glucoses, the influence of the mineral matter also 
 lowers the result from i to 2 per cent. The uncorrected 
 values are, however, sufficiently approximate to be valuable 
 for commercial work in determining the composition of 
 the product. The calculation in this case becomes : 
 
 log. R + colog. / -f colog. d+ 1.2367. 
 
 The true specific rotation , for the actual weight of i 
 gram of carbohydrate in i true cubic centimeter, can be 
 
 7? 
 
 calculated from [a]/,^ by multiplying by .99802 
 
 .00386, 
 
 the first factor being that for conversion of the values from 
 concentrations representing densities taken at 15.5, re- 
 ferred to Mohr cubic centimeters at 15.5, to densities at 
 15.5 referred to true cubic centimeters. The factors for 
 conversion of [a]/) 886 to true specific rotatory powers of 
 absolute weights of carbohydrates are given in the follow- 
 ing table : 
 
STARCH AND STARCH PRODUCTS 
 
 195 
 
 DENSITY FACTORS FOR REFERENCE TO ACTUAL WEIGHTS OF 
 ACID-HYDROLYZED STARCH PRODUCTS IN IOO TRUE CUBIC 
 CENTIMETERS OF SOLUTION 
 
 []l>386 
 
 Density fjlS^} 
 factors \ j 5 5 o/ 
 
 Logarithms of 
 conversion factors l 
 
 55 
 
 0.003837 
 
 9.9965 
 
 60 
 
 0.003844 
 
 9.9973 
 
 65 
 
 0.003850 
 
 9.9980 
 
 7o 
 
 0.003857 
 
 9.9988 
 
 75 
 
 0.003864 
 
 9.9996 
 
 80 
 
 0.003870 
 
 0.0002 
 
 85 
 
 0.003877 
 
 O.OOIO 
 
 90 
 
 0.003884 
 
 O.OOI8 
 
 95 
 
 0.003890 
 
 O.OO24 
 
 100 
 
 0.003897 
 
 O.OO32 
 
 105 
 
 0.003904 
 
 O.OO4O 
 
 110 
 
 O.OO39II 
 
 O.OO48 
 
 115 
 
 0.003918 
 
 0.0056 
 
 120 
 
 0.003925 
 
 0.0063 
 
 I2 5 
 
 0.003931 
 
 O.OO7O 
 
 130 
 
 0.003938 
 
 O.OO78 
 
 135 
 
 0.003945 
 
 0.0085 
 
 I40 
 
 0.003951 
 
 O.OO92 
 
 145 
 
 0.003958 
 
 O.OIOO 
 
 150 
 
 0.003965 
 
 0.0107 
 
 155 
 
 0.003971 
 
 0.0114 
 
 160 
 
 0.003978 
 
 O.OI2I 
 
 165 
 
 0.003985 
 
 O.OI29 
 
 170 
 
 0.003991 
 
 0.0136 
 
 175 
 
 0.003998 
 
 0.0144 
 
 1 80 
 
 O.OO4OO5 
 
 O.OI5I 
 
 185 
 
 O.OO4OII 
 
 0.0157 
 
 190 
 
 O.OO40I7 
 
 0.0164 
 
 195 
 
 0.004023 
 
 0.0170 
 
 Mog. 
 
 0.00386 
 
 0.99802. 
 
196 STARCH AND STARCH PRODUCTS 
 
 In conversion of K 386 to K absolute, since the cupric- 
 reducing power of pure dextrose, taken as i.oo for the 
 factor .00386, is .9915 in absolute value, it is necessary to 
 add the cologarithm of this number, or .0037, to the loga- 
 rithm of the conversion factor in calculating the reducing 
 power in terms of that of the equivalent weight of detrose 
 as unity. 
 
 Determination of the Cupric-reducing Power. In deter- 
 mining the cupric-reducing power of hydrolyzed starch 
 products, the original solution must be diluted sufficiently 
 to give about .2 gram of copper. With the Defren method, 
 this means, in most cases, a dilution of the original solu- 
 tion to Q of its original concentration ; taking, for in- 
 stance, 25 cubic centimeters of the original solution, and 
 diluting to 500 cubic centimeters. Since the original weight 
 of carbohydrate is determined from the amount in 100 cubic 
 centimeters, and the volume of the solution taken for the 
 Defren-Fehling test is 25 cubic centimeters, the copper 
 reduced by the amount of carbohydrate in the original 
 solution is obtained under these conditions by multiplying 
 the actual weight by 80. 
 
 The calculation is expressed by the following equation : 
 
 Cpe 
 
 K__ 
 > 
 
 d I 
 F 
 
 where p is the ratio of the concentration of the original 
 solution to that of the solution diluted for the Fehling 
 test, e is the " dextrose equivalent " of the copper as given 
 by a table calculated for the method used, and C is the 
 weight of copper (or its oxide) actually weighed. The 
 actual weight of carbohydrate in 100 cc. of solution is 
 
STARCH AND STARCH PRODUCTS 197 
 
 obtained from the density factor, either using the value, 
 .00386, as has been customary in commercial work, or the 
 true factor obtained from the determination of specific 
 rotary power as described. 
 
 Diastase-converted products, such as beer worts or malt 
 products, are determined in an analogous way, but as dex- 
 trose is usually absent, the equations expressing the primary 
 constituents are modified accordingly. Moreover, as the 
 malt itself contains considerable quantities of cane and 
 invert sugars, corrections must be made for these carbo- 
 hydrates when malt extract is present in appreciable 
 quantity, and the determination of the actual carbohy- 
 drate constituents becomes a complicated one. 1 
 
 Determination of the Constitution of Hydrolyzed Starch 
 Products from their Specific Rotatory Power. As already 
 stated, the large amount of experimental data on acid- 
 hydrolyzed starch products obtained under many diverse 
 conditions of hydrolysis points to the important con- 
 clusion that, in acid conversion, products of the same 
 specific rotatory power have the same composition, irre- 
 spective of the source of the starch, the nature or amount 
 of the hydrolyzing acid, or the temperature conditions, 
 these influencing the rate of hydrolysis only. 
 
 This constant relation holds true only with products of 
 the starch itself which have all been subjected to the 
 same conditions of hydrolysis, and not to mixtures of 
 products at different stages of conversion hydrolyzed 
 under different conditions. Moreover, in the case of 
 products hydrolyzed with acid of considerable strength 
 
 1 See Moritz and Morris, "Textbook of the Science of Brewing," or Heron's 
 article on Sugar in Thorpe's " Dictionary of Applied Chemistry," p. 669. 
 
1 98 
 
 STARCH AND STARCH PRODUCTS 
 
 or at high temperature, there are always some decompo- 
 sition or so-called "reversion" products formed to some 
 extent. These introduce some error in the higher con- 
 verted products. The nature and conditions of forma- 
 
 
 200 190 180 170 160 150 140 ISO 120 -410 TOO 90 80 70 fiO > 5C 
 
 00 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 52.7 
 
 ^'[CPlD ' 
 
 = 1.0 
 
 OK. 
 
 ^Pr 
 
 ..\ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 * 
 
 
 -.80 
 
 i 
 j 
 
 ; .70 
 
 < 
 
 ! 
 
 ~ 60 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ '- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 + 
 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 + 
 
 
 '^ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 s+ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ./ 
 
 '/ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 X 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 A -W 
 ) 
 
 
 
 
 J 
 
 ^ .30 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 s 
 
 'S 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^x 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ; 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 S. 
 
 + 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 . 
 
 S- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 s 
 
 *' 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 / 
 
 ' ' 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 / 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 .10 
 
 
 
 
 
 + + 
 
 /- 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 
 Thei 
 202. fc 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 r^] n ) 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Specific Rotation (CfC] D ) 
 
 FIG. 32. CURVE OF RELATION OF CUPMC-REDUCING POWER TO SPECIFIC 
 ROTATION OF ACID-HYDROLYZED STARCH PRODUCTS. 1 
 
 tion of these products, which under ordinary conditions 
 are present only in very small quantities, are by no means 
 thoroughly understood. In many cases, there seems to 
 be a slight loss in carbohydrate from the breaking up of 
 
 1 The dots and crosses represent reducing values actually obtained by 
 experiment, the crosses being results from products separated by alcoholic 
 precipitation. 
 
STARCH AND STARCH PRODUCTS 
 
 199 
 
 the molecule through oxidation. As a rule, these bodies 
 are present in negligible quantities. 
 
 Brown, Morris, and Millar have published the results of 
 over five hundred analyses, conclusively proving that the 
 law of constant relation between optical rotation and 
 cupric reduction does exist in diastase-conversion prod- 
 ucts of starch. 
 
 The relations between optical rotation and cupric reduc- 
 tion of products of the two kinds of hydrolysis are graphi- 
 cally shown in the preceding diagram. 
 
 From the values thus obtained, by calculation by the 
 equations given on page 192, the following curves have 
 been plotted, which show the per cent of primary con- 
 
 IUU 
 
 90 
 1 70 
 
 
 
 I 50 
 
 <30 
 20 
 
 Sio 
 
 
 
 I 
 
 -3 
 
 I 
 
 
 
 
 
 
 
 
 
 
 
 
 
 / 
 
 IUU 
 9O 
 80 
 70 
 60 
 50 
 40 
 30 
 20 
 10 
 O 
 
 
 
 
 
 
 
 
 
 
 
 
 
 / 
 
 
 
 V 
 
 Ss 
 
 
 f 
 
 *' 
 
 
 
 
 
 
 
 A 
 
 *$* 
 
 
 
 
 
 \\ 
 
 V 
 
 \ 
 
 t 
 
 
 
 
 
 
 
 /$ 
 
 
 
 
 \v 
 
 s 
 
 
 
 
 
 
 / 
 
 
 
 
 
 
 
 
 / \ 
 
 \ 
 
 ><r 
 
 *~ 
 
 
 , 
 
 4 
 
 
 
 
 
 
 
 
 of'' 
 
 / 
 
 \ 
 
 \ 
 
 \ 
 
 . 
 
 / 
 
 
 ^ 
 
 . 
 
 
 
 
 
 4 
 
 7 
 
 
 \ 
 
 
 ^ 
 
 <\ 
 
 
 
 
 s 
 
 \ 
 
 
 
 
 / 
 
 
 
 ^ 
 
 y 
 
 
 
 ^ 
 
 ^ 
 
 
 
 N 
 
 \ 
 
 
 / 
 
 
 ^ 
 
 ^ 
 
 
 
 
 
 
 
 v> ^ 
 
 . 
 
 - 
 
 * 
 
 S 
 
 195 C 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 b 
 
 190 170 150 130 110 90 7O 50 
 
 SPECIFIC ROTATI 
 
 FIG. 33. RELATION OF THE CARBOHYDRATE CONSTITUENTS OF ACID AND 
 DlASTASE-HYDROLYZED STARCH PRODUCTS TO THEIR SPECIFIC ROTATION. 
 
 stituents in hydrolyzed starch products (calculated for the 
 factor .00386). The dotted lines represent the products 
 of diastase conversion (see Table No. 5 in Appendix). 
 From such curves the constitution of any pure hydro- 
 
2OO STARCH AND STARCH PRODUCTS 
 
 lyzed product can be determined from its specific rotatory 
 power. In practice there are comparatively few commer- 
 cial products pure enough to permit of their constitution 
 being determined in this simple manner. In the case of 
 commercial ''glucoses," however, which contain but traces 
 of foreign substance, this method is most valuable, not only 
 in factory control, but for valuation of different lots of 
 product for the purposes for which the glucose is to be used. 
 
 Manufacture of Commercial Glucose and Grape Sugar. 
 The word "glucose" is used to mean different things, and 
 consequently there is considerable misunderstanding as to 
 what is meant by the term. In Europe, especially Eng- 
 land and France, the word is synonymous with dextrose, 
 or "starch sugar." In America this latter product is in- 
 variably called "grape sugar," glucose being applied to 
 the thick viscid sirup which is manufactured in large 
 quantity by the partial hydrolysis of starch with acid. It 
 is in this popular signification that glucose is used here. 
 As used in a previous chapter, it is employed, as in organic 
 chemistry, as a class term to designate a group of hexose 
 sugars. 
 
 The manufacture of glucose is carried on on an enor- 
 mous scale in this country, in conjunction with that of 
 starch and numerous valuable by-products, which latter 
 will only be alluded to in the following description. 1 
 
 In the manufacture of " glucose " two conditions are 
 imperative: (i) The amount of dextrin must be sufficient 
 to prevent the separation of crystallized sugar when the 
 
 1 Taken from a paper on the manufacture of brewing sugars, written by 
 the author and George Defren for the North British Federated Institutes of 
 Brewing of Manchester, England, in 1899. 
 
STARCH AND STARCH PRODUCTS 2OI 
 
 product is concentrated to 45 Be., or about 84 per cent. 
 (2) Under similar conditions dextrin should not separate 
 out. These conditions limit the conversion stages to those 
 represented by that part of the diagram (Figure 33) lying 
 approximately between the rotation figures, 150 and 100. 
 Commercial glucoses in the market vary in polarization 
 from [a] ^386= 145 to i?o. As the greatest consumption 
 of glucose is in the manufacture of candies, jellies, and 
 sirups, its composition has been determined by the de- 
 mands of these trades. The use of glucose in beers, 
 extensive as it is, takes a very small proportion of the 
 total output. On this account there are practically two 
 grades of glucose on the market, leaving out of considera- 
 tion goods which differ only in concentration : mixing 
 (sirup) glucose, with a conversion of [a]/)3 86 = 120 130 ; 
 and confectioners' goods of [a] />==! 30 140. The 
 best confectioners' goods are commonly about [a] #386 = 
 135. There is by no means a rigid standard, however; 
 in- fact, many manufacturers grade according to the per- 
 fection of refining, the clearer, whiter glucose, independent 
 of its conversion, being specially treated for confectioners' 
 use. Jelly goods differ from mixing glucose merely in 
 concentration, although imperfectly refined candy glucose 
 is often worked up into this grade, as a slight turbidity 
 or tint is of no consequence in jelly manufacture. Mixing 
 glucose is the kind usually bought by the brewer. The 
 composition may vary through wide limits, the proportion 
 of dextrin, for instance, varying in extreme cases about 
 100 per cent. In short, the commercial grading of a glu- 
 cose is no criterion of the relative proportion of dextrose, 
 maltose, or dextrin. 
 
2O2 
 
 STARCH AND STARCH PRODUCTS 
 
 Space permits only the most superficial description of 
 the manufacture of glucose. In general the process con- 
 sists of three parts : (i) separation of the starch ; (2) con- 
 version ; (3) refining. (The diagrammatic scheme (Fig. 34) 
 will assist in following this description.) All kinds of what 
 is known as No. 3 or No. 4 corn (maize) are used. This 
 
 (1A) GERM MEAL 
 
 NEUTRALIStB 
 BAG -FILTERS 
 
 BONE BLACK FILTERS 
 
 LE-EFFECT-EVAPORATO 
 
 BONE-ELACK:FILTERS 
 
 o 
 
 VACUUM PAN 
 
 FIG. 34. - 
 
 (4) FINISHED-GLUCOSE 
 
 -DIAGRAMMATIC SCHEME OF THE MANUFACTURE OF COMMERCIAL 
 GLUCOSE. 
 
 corn is taken from the cars or the elevator of the works 
 to the steep tubs, which hold 2000 bushels or more. In 
 steeping, water at 150 F. is used at first, then the steep is 
 allowed to cool till a temperature of about 90 F. is reached. 
 Sulphurous acid is used to prevent putrefaction and assist 
 softening. The steeping lasts from three to five days. 
 The separation of the starch consists of (i) grinding the 
 
STARCH AND STARCH PRODUCT^ 2O3 
 
 wet grain mixed with water, and softened by steeping; 
 (2) separating the starch grains from the woody fibre and 
 germ by washing through sieves of bolting cloth, rapidly 
 shaken ; (3) settling out the starch from the gluten by sub- 
 sidence while passing over gently inclined runs (" tables "). 
 The grinding is done so that the starch grains are set free, 
 ^ut not ruptured. The germ is removed separately in 
 many factories. This is accomplished by coarse grinding 
 and running the grain mixed with much water through a 
 long trough, or into a tank, the mass being agitated slowly. 
 The germ which floats is carried off by one channel, the 
 rest of the grain by another. This separation of the germ 
 is an important improvement, since the oil which is con- 
 tained in it (about 35 per cent) can be readily obtained as 
 a by-product, 1 and the quality of the glucose is much im- 
 proved by its removal. The grain from the separators is 
 ground and washed on the sieves (" shakers ") in the usual 
 manner, and the separated liquor sent over the runs. The 
 thin, highly diluted gluten is allowed to settle, pumped 
 through filter presses, and the dried cake, which contains 
 over 30 per cent of protein, sold for cattle feed. 
 
 The starch collected on the runs, and containing about 
 50 per cent of moisture, is now mixed with water to a thick 
 cream of about 20 Be., preparatory to conversion. Con- 
 version is carried on in large copper boilers at a steam pres- 
 sure of 30 pounds, hydrochloric acid being the converting 
 agent, the amount used being about .0006 of the weight 
 of the starch. 
 
 1 One of the important uses of corn oil is in making "rubber" floor 
 matting. Vulcanized corn oil makes an excellent rubber substitute for such 
 purposes. It is also an adulterant of genuine rubber. 
 
2O4 
 
 STARCH AND STARCH PRODUCTS 
 
 In some factories sulphuric acid is still used as the hy- 
 drolyzing acid. In the manufacture of candy goods and 
 certain hard sugars it seems to have some advantages. 
 
 Oxalic acid has 
 been used for the 
 manufacture of 
 fine candy glu- 
 cose. In the 
 manufacture of 
 grape sugar a 
 much larger pro- 
 portional amount 
 of acid is used, 
 in some cases up 
 to i per cent 
 
 FIG. 35. SECTION OF CONVERTER. 
 
 A. Perforated steam pipe. D. Acid pipe. 
 
 B. Starch liquor pipe. F. Washout pipe. 
 
 C. Discharge pipe to neutralizer. O. Discharge valve. 
 
 V. Air-vent pipe. 
 (From Thorp's " Outlines of Industrial Chemistry.") 
 
 or more of the 
 weight of starch. 
 The point: of com- 
 plete conversion is usually controlled by the disappearance 
 of the dextrin precipitate when the liquid is poured into 
 alcohol. 
 
 In glucose conversion the acid is mixed with about fifty 
 times its bulk of water, and is run into the "converter." 
 Steam is then turned on till a pressure of 30 pounds is ob- 
 tained. This pressure is maintained while the starch milk 
 is pumped in, which takes about half an hour. Heating is 
 continued after this for 40 minutes or more. " Dirty " 
 starch, containing much gluten, increases the time of con- 
 version 10 minutes or more. The degree of conversion is 
 entirely controlled by iodine tests. By daily practice, work- 
 men become quite expert in making these tests, yet from 
 
STARCH AND STARCH PRODUCTS 
 
 205 
 
 week to week there is apt to be considerable variation 
 in composition when tests are not checked by chemical 
 control by determining the specific rotation of the liquids 
 from the bone-black filters. 
 
 The refining process is, in general, similar to that of cane 
 sugar. The analogy is quite close in the case of the solid 
 grape sugars. In the case of glucose, however, there is a 
 radical difference of principle which must not be over- 
 looked. In the refining of glucose the purification must be 
 carried to great lengths, at least as far as color and ap- 
 pearance are concerned. All bodies affecting these char- 
 acteristics must be absolutely removed from the liquid, or 
 bleached in it, since there is no mother liquor in which they 
 can be deposited, as in the case of a crystalline sugar. On 
 this account the 
 refining of glucose 
 is a much more 
 delicate process 
 than that of sugar. 
 
 Neutralization 
 is an important 
 part of the refin- 
 ing, as on the 
 thoroughness with 
 which this is done 
 depends how suc- 
 cessfully the albu- 
 minoids, calcium, 
 and iron salts are removed. As soon as the conversion 
 is completed the liquid is blown out into the " neutralizer," 
 where the alkali, usually sodium carbonate, is added. In 
 
 FIG. 36. SECTION OF NEUTRALIZER. 
 
 A . Revolving stirrer. 
 
 B. Sprinkler pipe for alkaline neutralizing liquid. 
 
 C. Discharge pipe from converter. 
 
 (From Thorp's " Outlines of Industrial Chemistry.") 
 
206 STARCH AND STARCH PRODUCTS 
 
 many factories it is the practice to cool the liquids con- 
 siderably before neutralizing, but this seems unnecessary 
 when the alkali is added properly. The liquid when 
 neutralized should show only the acidity caused by carbon 
 dioxide or the weakest vegetable acids. The properly 
 neutralized liquid is clear and of a bright amber color, 
 but contains large flocculent masses of coagulated gluten, 
 which, in a test tube of ordinary size, form a layer about 
 half an inch thick. When the proper point of neutraliza- 
 tion is attained, this layer is greenish drab, owing to the 
 precipitated iron. 
 
 As in sugar refining, the precipitated matter is removed 
 by bag filters, which are often supplemented by a press 
 filtering. In the case of highly refined glucoses, precipi- 
 tants are sometimes used, such as alum. The tendency 
 seems to be for manufacturers not to push this part of the 
 refining to greatest advantage, but rather to depend on a 
 liberal use of bone black to do much of what it would seem 
 could be accomplished by less expensive means in prelimi- 
 nary clarification. The bone-black treatment is quite com- 
 plicated, not only in the details of filtering, but in the 
 preparation of the black. Since the slightest trace of alkali 
 in contact with hot liquor will produce a brown stain of 
 caramel, removable only to a limited extent by bone black, 
 the black itself must be freed from all traces of ammonia 
 or caustic lime by a careful " tempering " with hydro- 
 chloric acid or some similar treatment, and subjected to a 
 careful washing to remove soluble salts of iron and calcium. 
 The glucose liquors are, as a rule, put over the bone black 
 twice: first at their original concentration, about 18 Be.; 
 and again after concentration to 28-30 Be., the denser 
 
STARCH AND STARCH PRODUCTS 
 
 207 
 
 sirup going over the freshly tempered black. The re- 
 vivifying of the black is carried out on lines similar to 
 those of cane-sugar refining. 
 The " heavy liquor " goes 
 directly from the filters to 
 the vacuum pan in most 
 modern factories. Formerly 
 a preliminary filtration was 
 necessary to remove the 
 calcium sulphate which sep- 
 arated out, but with the use 
 of hydrochloric acid con- 
 versions and neutralization 
 with soda this is avoided. 
 In the final concentration 
 sulphites are added in 
 amounts varying from .008 
 
 37. SECTION OF BONE-BLACK 
 FILTER. 
 
 A . Perforated false bottom on which bone black 
 
 sulphites is as follows : sts. 
 
 B. Discharge pipe for filtered liquor, 
 (l) tO prevent Oxidation C. Entrance pipe for liquor. 
 
 D. Steam pipe. 
 
 and consequent coloration E. Air-vent P i pe . 
 
 ,, r- , ,. F,H,J,L. Steam, wash- water, and sewer con- 
 
 in the final concentration necdons. 
 
 due to formation of caramel- G ' ^^ pe ** Wash! " 8 U ' *""* 
 
 like bodies, and Sometimes ^,. Tank connections, coupled by hose 
 
 ferric SaltS' (2} tO bleach* ( From Thorp's " Outlines of Industrial Chem- 
 istry.") 
 
 (3) to prevent fermentation 
 
 of the less concentrated finished products, as the thinner 
 mixing sirups ; (4) in candy goods, as a preventive of oxi- 
 dation in the candy kettle. Confectioners' goods are more 
 heavily " doped " with sulphites than others. 
 
 to .050 per cent SO 2 . FlG - 
 
 The function of these 
 
208 STARCH AND STARCH PRODUCTS 
 
 The refining for the making of ordinary commercial 
 grape sugar, which is a waxy concrete of the hydrated 
 dextrose, C 6 H 12 O 6 H 2 O, and partially hydrolyzed com- 
 pounds, together with some products of decomposition 
 is practically identical with that of glucose. The con- 
 centrated sirups are drawn off into pans or barrels and 
 allowed to solidify, a "seed" of crystallized sugar often 
 being added to facilitate crystallization. Anhydrous grape 
 sugar is made in a similar way from a sirup which is re- 
 fined at lower concentrations throughout the process in 
 order to obtain a purer product. In this case the " seed " 
 is selected with the greatest care from absolutely pure an- 
 hydride, all hydrated crystals being scrupulously excluded. 
 The crystallization is complete in about three days, when 
 the sugar is purged in centrifugals. The purged liquors 
 are often worked up into the "climax" sugars, a dark 
 product used by brewers. These sugars also are often put 
 on the market as "chips." Glucose sirups are usually 
 made at five concentrations: 41, 42, 43, 44, 45 Be. 
 Mixing goods are usually finished up at 41 Be. The 
 higher concentrated products are confectioners' or jelly 
 goods, the former being characterized by greater perfection 
 of refining and a large amount of sulphites. 
 
 As to the manner of taking concentration determinations, 
 the glucose manufacturers do not use the same scale as the 
 sugar refiners, who employ Gerlach's modification. The 
 glucose scale is practically identical with that used by 
 the alkali manufacturers, and has the following conversion 
 
 formula for the density : d= Owing to the great 
 
 144 Be. 
 
 viscosity of glucose, the readings are taken, not at the 
 
STARCH AND STARCH PRODUCTS 2C>9 
 
 scandard temperature of the instrument (60 F.), but at 
 1 00. The slightly warmed glucose is poured into a cylin- 
 der, preferably of glass, which is placed in a water bath at 
 1 00 F. At the end of half an hour or so, the glucose will 
 have reached the temperature of the bath, and the air bub- 
 bles will have escaped. A Beaume spindle, reading to 
 fifths, is then cautiously lowered into the glucose and 
 allowed to come to equilibrium, which in the more viscous 
 samples takes some minutes. With care the determination 
 can be made on a Westphal balance. All samples of glu- 
 cose should be tested for density, as the viscosity in goods 
 of different conversions varies to a marked degree. A low- 
 converted sample of moderate density will apparently have 
 much more " body " than a high-converted glucose much 
 more concentrated. 
 
 As, apart from concentration, the quality of commercial 
 glucose is largely judged by its appearance, it will be inter- 
 esting to consider briefly some of the turbidities and colora- 
 tions of the commercial products, their causes, and actual 
 influence on the quality of the glucose. A well-refined 
 glucose is practically colorless and clear. If a white glass 
 cylinder is filled with glucose, the color of the sample can 
 be seen, as well as any turbidity. If the color is a pure 
 white, the sample is dyed, as can be proved by exposing it 
 to the light for a few days, although this coloring is rarely 
 done so well that a close inspection will not reveal the violet 
 tint. As all glucoses darken slightly on exposure to the 
 light, the color balance soon becomes disturbed, and the 
 presence of the dye is made more evident. If no dye is 
 present, the glucose, unless quite turbid, will show some 
 color, usually green or yellow. These tints are almost 
 
210 STARCH AND STARCH PRODUCTS 
 
 invariably present, and seem to be caused by traces of iron 
 salts and vegetable coloring matters. They are of little 
 consequence, except as indicators of the thoroughness of 
 the refining, and, hence, of the removal of albuminoids 
 and oil. A reddish brown discoloration is the result of 
 excess of alkali, as a rule either through imperfect neutral- 
 ization or defective treatment of bone black. 
 
 Cloudiness caused by faulty conversion, separation of 
 dextrins in one case or sugar in the other, is in these days 
 of rare occurrence. A smoky appearance is often caused 
 by bone-black dust, or in some cases from iron sulphide, 
 when a large quantity of new black is used in refining ; 
 these faulty results, of course, are from improper prepara- 
 tion of the black. White cloudiness is usually caused either 
 by calcium salts or by organic growths due to fermentation. 
 The former may be sulphate or phosphate. Sulphates in 
 goods converted by hydrochloric acid are in the main in- 
 troduced through use of impure acid, or in sulphite liquors ; 
 phosphates, from excess of "tempering acid," or incomplete 
 washing of the black. The clouds due to fermentation, 
 which naturally are more common in goods made in hot 
 weather, are usually the result of storing thin liquor (in 
 process) at too low a temperature. Of course the fermen- 
 tation organisms can easily be identified by the microscope. 
 A quick way of identification is to acidulate the sample 
 with hydrochloric acid, when the ferment cloud remains 
 undissolved. 
 
 Solutions of grape sugar show the same characteristic 
 colorations and turbidities, in a greater or less degree. 
 Usually they show caramel tints, owing to the decomposi- 
 tion products, especially in inferior goods. 
 
STARCH AND STARCH PRODUCTS 211 
 
 The valuation of the solid starch (grape) sugars is practi- 
 cally based on their dextrose content. Whiteness of late 
 years seems to be more of a desideratum than formerly; 
 hence the practice of dyeing is becoming common. The 
 principal mineral impurity objected to is iron. This is 
 rarely present in more than traces. A delicate test for 
 iron in sugars or glucoses is made with cochineal. Sul- 
 phites must be first removed, and the solution made neutral 
 or faintly alkaline. If iron be present, the pure crimson of 
 the cochineal gradually passes into violet. There are two 
 commercial grades of grape sugar, ordinarily, " seventy " 
 and "eighty" sugar, the numbers referring to the assumed 
 dextrose content. 
 
 A "glucose " of high quality, made by primitive methods 
 by conversion of the starch matter of rice or millet by 
 malt infusion, has existed in Japan for centuries. 1 This 
 "midzu-ame" (freely translated, "liquid candy") is a 
 transparent, amber-tinted, viscid sirup, much resembling 
 commercial glucose in its properties, but of course free 
 from more than the merest traces of dextrose. In short, 
 it is essentially a pure starch-conversion product, the com- 
 position of which can be determined from its specific rota- 
 tion, analogously to such determinations of acid-hydrolized 
 glucose, but by means of the equations applying to diastase 
 conversions. 
 
 Midzu-ame, in one form or other, has long played a very 
 important part in the domestic economy of Japan. In 
 
 1 Yoshida, Chemical News, 43, 29; Skidmore, " Jinrikisha Days in Japan," 
 37 ; Wiley, Agric. Science, 6, 57 ; Storer and Rolfe, Bull. Bussey Institu- 
 tion, Harvard Univ., 3, 80 ; Yei-Furukawa (translation by Takaki), ibid, 9 
 3 95- 
 
212 STARCH AND STARCH PRODUCTS 
 
 some measure it still takes the place which sugar occupies 
 in Western nations. It is of peculiar interest, as represent- 
 ing an advanced development of a sweet barley wort, which 
 must have been used to considerable extent by many commu- 
 nities of Europe, before the advent of cane sugar, which 
 began to be of common use only in the sixteenth century. 
 
 Manufacturing Losses. The first loss in manufacture 
 occurs in the soluble matter which is in the liquors drained 
 off from the steep tubs. Practically no starch is lost, 
 although a trace is found in the steep water, from oc- 
 casional broken grains, but there is a considerable loss of 
 valuable food materials, carbohydrates, oil, and albumi- 
 noids. In many places it has been found profitable to 
 recover this material by evaporating the steep waters in a 
 multiple-effect to a thick sirup, and adding this to the 
 gluten meal or other by-products used as cattle feed. 
 The steep waters contain 5 to 6 per cent of this soluble 
 food matter, and, moreover, make an offensive sewage if 
 allowed to run into a stream. 
 
 The corn itself is graded largely on the moisture it con- 
 tains. According to Archbold, the average composition 
 of " No. 4 " corn, the kind usually used in starch and glu- 
 cose manufacture, is : 
 
 Oil 5.20 per cent 
 
 Carbohydrates (Starch, 54.8 per cent) 71.22 
 
 Albuminoids ("Gluten") . . 10.46 
 
 Ash 1.52 
 
 Water n.6o 
 
 The next loss of starch occurs in the bran, or " wet feed," 
 the amount found here being a measure of the efficiency 
 
STARCH AND STARCH PRODUCTS 2 1 3 
 
 of the removal of the starch from the cells of the grain in 
 the mechanical separations, and incidentally of the steeping. 
 
 Determination of starch in the gluten liquors, passing 
 off from the " runs " or " tables " for depositing the starch, 
 shows the amount passing away in the gluten. This may 
 vary considerably according to the efficiency of the steep- 
 ing, and also very largely to the skill of the " paddlers," 
 workmen who keep the surface of the deposited starch 
 clean, and the stream of starch and gluten flowing slowly 
 and evenly down the runs. These men prevent the par- 
 tially coagulated gluten from accumulating at any point, and 
 remove the occasional accidental obstructions which effect 
 serious loss of starch by causing currents to cut into the 
 deposited mass. The starch lost in the gluten liquors may 
 amount to from 20 to 70 pounds per 1000 gallons. This, 
 however, is saved in the by-product (gluten meal), and to 
 some extent is necessary to facilitate the filtering in the 
 gluten filter presses. 
 
 With the exception of a small amount of starch possibly 
 passing into the germ meal, the only other losses in starch 
 manufacture normally occur in washing, filtering, and 
 handling the product in the kilns and packing, and are 
 comparatively small, though unavoidable. 
 
 The mechanical losses in the conversion and refining of 
 the glucose are practically the same as in sugar refining. 
 The chemical losses are much less, as the glucose liquors 
 do not hydrolyze appreciably under the conditions of re- 
 fining. Aside from the slight decomposition during hydrol- 
 ysis, already referred to, the only source of destruction is 
 in the neutralizing, where portions of the hot liquor may 
 come in contact with an excess of alkali (sodium car- 
 
214 ' STARCH AND STARCH PRODUCTS 
 
 bonate) if the process is not properly carried out. In 
 making grape sugar, a certain amount of destruction of 
 sugar is inevitable. Special care must be taken, in hot 
 weather, to avoid fermentation of thin liquors in process. 
 The chemical control of the bone black is practically the 
 same as in sugar refining. 
 
 Valuation of Commercial Corn Starch. In general, 
 starches are divided into three grades, alkaline or " chemi- 
 cal," acid, and neutral starches, according to the reactions 
 given with test paper. Alkaline starches are those in 
 which caustic soda has been mixed before running on the 
 tables, in order to make the gluten more soluble and so 
 effect a more perfect separation. Acid starches were origi- 
 nally made by fermenting the gluten. Neutral starches, 
 so called, are made by use of sulphite liquors in steeping 
 and running the starch, the usual modern method. Ordi- 
 nary starch is " thick-boiling," making a stiff paste when a 
 5 per cent mixture of starch in water is heated to boiling. 
 By suitable treatment of starch with dilute acid, at temper- 
 atures far below the bursting point of the granule, the 
 starch undergoes a gentle hydrolysis, and becomes " thin- 
 boiling," although its appearance and other general char- 
 acteristics remain unchanged. Textile manufacturers for 
 years have availed themselves of this property, either by 
 heating starch with 'acetic acid or other weak hydrolyte, or 
 by allowing the moistened starch to undergo incipient fer- 
 mentation. Owing to the greater penetrating power of the 
 fluid paste, thin-boiling starches are peculiarly applicable 
 in sizing or stiffening textiles, as a large amount of starch 
 can be introduced into the fabric without coating the sur- 
 face. Consequently the viscosity, or, as it is usually stated 
 
STARCH AND STARCH PRODUCTS 21$ 
 
 iii commercial work, the " fluidity," of the paste which the 
 starch makes when mixed with water in standard propor- 
 tion is an important criterion of its value for certain pur- 
 poses. These fluidity tests are made in various ways, but 
 the somewhat crude commercial methods depend on the 
 number of cubic centimeters of a 5 per cent starch paste, 
 made by rupturing the grains with a weak solution of 
 caustic alkali, which will run out of a funnel through a 
 capillary orifice in a definite period, the paste being at 
 standard laboratory temperature, and the instrument ad- 
 justed so that 100 cubic centimeters of pure water will run 
 out of the instrument under the same conditions. Thus, 
 an "80" thin-boiling starch gives a paste which has 80 
 per cent the "fluidity" of water, measured in this way. 
 A more accurate method of measuring fluidity is by the 
 Doolittle torsion viscosimeter, which measures the angular 
 loss in the oscillation of a torsion pendulum whose cylin- 
 drical bob is immersed in the paste. The supporting wire 
 is first twisted, by a special device, through an angle of 
 360, and the pendulum then released, the difference in 
 reading at the end of a complete oscillation (the reading, 
 for instance, at the end of a period of swing to the right, 
 and the reading at thfc end of the next period of swing to 
 the right, neglecting the reading at the end of period of 
 swing to the left) is the angular measurement of the loss 
 due to retardation by the viscosity of the liquid. These 
 readings should be checked by turning the wire in the 
 opposite direction, and taking a new set of readings. 1 The 
 instrument is usually standardized to express the viscosity 
 
 1 See Gill's " Handbook of Oil Analysis " for a more complete description 
 of this instrument and manner of taking measurements. 
 
2l6 STARCH AND STARCH PRODUCTS 
 
 in terms of that of cane sugar, a curve being plotted to 
 show the concentration of sugar solutions, giving the vis- 
 cosities expressed by the angular retardations. With the 
 Doolittle viscosimeter, readings can be taken at any con- 
 venient temperature, as there is a water or oil jacket by 
 which the test solution can be heated. 
 
 Moisture. Starch under normal atmospheric condi- 
 tions contains 12-18 per cent of moisture, according to its 
 origin. This can be driven put by drying at 105 C, but 
 the dried product is extremely hygroscopic and rapidly 
 takes up moisture to the normal amount ; for instance, 
 maize starch absorbs about 12 per cent, potato 18 per 
 cent, which cannot be entirely removed at ordinary tem- 
 perature, even by shaking with alcohol. In fact a rapid 
 method of moisture determination has been developed for 
 potato starch which depends on the removal of part of the 
 water by alcohol. This will remove the water in excess 
 of a constant percentage (11.4). If the starch is dry, it 
 will take up water. The amount absorbed by or taken 
 from the alcohol is determined by taking its density. 
 A table has been prepared by Scheibler which gives 
 the per cent of moisture in the starch corresponding 
 to the density of the alcohol, when 100 cubic centi- 
 meters of alcohol and 41.6 grams of starch are shaken 
 together. 
 
 Saare's method, 1 which is very convenient, and precise 
 enough for technical purposes (giving results for potato 
 starch correct to .5 per cent), is as follows : 100 grams of 
 the starch are washed into a 25o-cubic-centimeter tared 
 flask and made up to the mark with water at 17.5- 
 
 1 Chem. Zcit., 52, 934. 
 
STARCH AND STARCH PRODUCTS 
 
 217 
 
 From the weight of the contents of the flask, the moisture 
 contained in the original starch sample is determined by 
 the following table : 
 
 WEIGHT FOUND 
 
 WATER PER CENT 
 
 WEIGHT FOUND 
 
 WATER PER CENT 
 
 289.40 
 
 O 
 
 277.20 
 
 31 
 
 289.00 
 
 I 
 
 276.80 
 
 32 
 
 288.60 
 
 2 
 
 276.40 
 
 33 
 
 288.20 
 
 3 
 
 276.00 
 
 34 
 
 287.80 
 
 4 
 
 275.60 
 
 35 
 
 287.40 
 
 5 
 
 275.20 
 
 36 
 
 287.05 
 
 6 
 
 274.80 
 
 37 
 
 286.65 
 
 7 
 
 274.40 
 
 38 
 
 286.25 
 
 8 
 
 274.05 
 
 39 
 
 285.85 
 
 9 
 
 273.65 
 
 40 
 
 285.45 
 
 10 
 
 273.25 
 
 4i 
 
 285.05 
 
 ii 
 
 272.85 
 
 42 
 
 284.65 
 
 12 
 
 272.45 
 
 43 
 
 284.25 
 
 13 
 
 272.05 
 
 44 
 
 283.90 
 
 14 
 
 271.70 
 
 45 
 
 283.50 
 
 15 
 
 271.30 
 
 46 
 
 283.10 
 
 16 
 
 270.90 
 
 47 
 
 282.70 
 
 17 
 
 270.50 
 
 48 
 
 282.30 
 
 18 
 
 270.10 
 
 49 
 
 281.90 
 
 19 
 
 269.70 
 
 50 
 
 281.50 
 
 20 
 
 269.30 
 
 5i 
 
 28I.IO 
 
 21 
 
 268.90 
 
 52 
 
 280.75 
 
 22 
 
 268.50 
 
 53 
 
 280.35 
 
 23 
 
 268.10 
 
 54 
 
 279.95 
 
 24 
 
 267.75 
 
 55 
 
 279-55 
 
 25 
 
 267.35 
 
 56 
 
 279.15 
 
 26 
 
 266.95 
 
 57 
 
 278.75 
 
 27 
 
 266.55 
 
 58 
 
 278.35 
 
 28 
 
 266.15 
 
 59 
 
 278.00 
 
 2 9 
 
 265.75 
 
 60 
 
 277.60 
 
 30 
 
 
 
2l8 STARCH AND STARCH PRODUCTS 
 
 Commercial starches often contain an excess of moisture. 
 Whiteness and freedom from offensive odor or taste are 
 necessary qualifications of good starch. 
 
 Size Compounds. Starch is used in immense quantities 
 in the weaving of cotton cloth as the chief ingredient of 
 size, which is applied to the warp to protect the threads 
 from chafing during the weaving. Other material is added 
 to the starch to make the size flexible, such as grease, or 
 calcium chloride, which latter, by its hygroscopic action, 
 prevents the size becoming brittle and brings about the 
 same result. Copper sulphate or zinc chloride (the latter 
 also having hydrolytic influence) is added in small quantity 
 to some sizes as an antiseptic to avoid molding or mil- 
 dewing. 
 
 There are numerous formulae for making these sizes, 
 which are usually prepared by the mill people themselves, 
 who mix the size ingredients with the starch paste ; which 
 latter has usually been put through some primitive process 
 to make it thin-boiling. The material to give the char- 
 acteristic properties to the size is usually in the form of 
 " size compound," being a mixture of the fatty or chemical 
 ingredients in a concentrated form in starch paste. As 
 the starchy material is unimportant in the valuation of 
 these size compounds, determinations should be made 
 of the fatty or chemical ingredients. 
 
 Dextrin and British Gum. The term "dextrin," like 
 "glucose," is a much overworked one, as it has many 
 significations. As already referred to, the numerous inter- 
 mediate products of starch hydrolysis which can be pre- 
 cipitated as definite compounds by alcoholic fractionation 
 are known as dextrins; but these, in their chemical and 
 
STARCH AND STARCH PRODUCTS 2IQ 
 
 optical behavior, can always be considered as molecular 
 aggregates of a primary "dextrin," whose characteristics 
 are well denned and persist in all such compounds, and 
 the hexose sugars, maltose and dextrose (or, in the case of 
 diastase-converted products, maltose alone), as has been 
 explained. " Dextrin," as used in commerce, refers to a 
 manufactured product of variable composition, made by 
 heating the starch to about 170 C. A certain degree of 
 hydrolysis is effected to a limited extent by the moisture 
 and acids in the starch, and is also in many cases produced 
 by moistening the mass with acid, sometimes hydrochloric, 
 but usually nitric. The darker products, which have been 
 subjected to a more prolonged heating, often to tempera- 
 tures as high as 270, without acid, and which give thicker 
 mucilages with water, are known as " British gums," al- 
 though there is no hard and fast distinction between these 
 products and the "dextrins." These " torref action dex- 
 trins," as they have been called to distinguish them, are 
 made by roasting in revolving cylinders, either directly 
 heated by a furnace or by an oil bath. In some processes 
 the conversion is carried on in metal trays, which are 
 placed on racks in a kiln. Color and "body " of the muci- 
 lages which these products make with hot water are the 
 principal criterion s by which they are judged. A good 
 dextrin or British gum should make a practically clear 
 solution with hot water, showing none of the pastiness or 
 colloidal appearance of the unconverted starch. These 
 products are used for a variety of purposes, especially in 
 the textile industries, as well as for mucilage, gum for 
 postage stamps, labels, etc., and in fact for all purposes 
 where a water-soluble gum is needed. There are no fixed 
 
22O STARCH AND STARCH PRODUCTS 
 
 rules for their manufacture, the amount of heating, acid, 
 and other conditions depending on the peculiar require- 
 ments of each consumer. Often different dextrins are 
 blended to obtain the requisite quality. 
 
 Chemically, they show a small but varying reducing 
 power, which is much less than corresponds to the optical 
 rotation as expressed by the "law of relation" of an acid- 
 hydrolyzed starch product. This would be expected, as 
 not only are products formed by the action of the heat 
 under conditions where all traces of water are absent, 
 except what may be formed by the decomposition of the 
 molecule, but the higher converted and more sensitive 
 products formed in the preliminary hydrolytic action, 
 which always takes place, are to considerable extent 
 destroyed and converted into caramel bodies. 
 
 A determination of the specific rotation of a torrefaction 
 dextrin, however, in connection with the cupric-reducing 
 power, often throws valuable light on the conditions of its 
 manufacture. Viscosity tests are most useful in the valua- 
 tion of a dextrin, speaking generally, but the peculiar use 
 for which the dextrin is designed often demands special 
 requirements. Starches of different kinds also give differ- 
 ent qualities of dextrin. Most of these dextrins and Brit- 
 ish gums are in the form of powders, which, if freshly 
 made, will show under the microscope the form of the 
 original starch grains from which the product has been 
 obtained. Some forms, as "gommelin," are in the state 
 of glassy grains much resembling gum arabic, and are 
 fairly pure hydrolyzed products. Starch " pastes " are made 
 by a gentle hydrolysis, usually with acetic acid, and then 
 thickened with borax, which makes a very stiff mass. 
 
STARCH AND STARCH PRODUCTS 221 
 
 SOME PAPERS ON STARCH AND ITS DERIVATIVES, 
 BEARING ON SUBJECT 7 MATTER OF PREVIOUS 
 CHAPTER 
 
 Musculus and Gruber. Bull. Soc. chim. (2), 30, 54. 
 
 Bondonneau. Compt. rend., 81, 972; Bull. Soc. chim. (2), 28, 452. 
 
 O'Sullivan. J. Chem. Soc. (London), 25, 579; 29, 479; 30, 125. 
 
 Wiley. Proc. A. A. A. S., 30, 65. 
 
 Brown and Heron. Ann. Chem., 199, 242 ; 231, 125 ; J. Chem. Soc. 
 (London), 35, 596. 
 
 Saloman. J. pr. Chem. (2), 28, 82. 
 
 Schulze. Ibid. (2), 28, 311. 
 
 Brown and Morris. J. Chem. Soc. (London), 47, 52'7 ; 53, 510; 55, 
 449; 63, 604. 
 
 Brown, Morris, and Millar. Ibid., 67, 830 ; 71, 72 ; 75, 286 ; 75, 308. 
 
 Brown and Glendinning. Ibid., 81, 388. 
 
 Scheibler and Mittelmeier Ber. deut. chem. Ges., 23, 3060. 
 
 Lintner and Dull. Ibid., 26, 2553. 
 
 Ling and Baker. J. Chem. Soc. (London), 67, 702. 
 
 Rolfeand Defren. J. Am. Chem. Soc., 18,869; (Revised : Tech. 
 Quart., 10, 133). 
 
 Rolfe and Faxon. Ibid., 19, 698. 
 
 Rolfe and Defren. J. Fed. Inst. of Brew., 5, 59; Tech. Quart., 12, 
 191. 
 
 Rolfe and Geromanos. J. Am. Chem. Soc., 25, 1003. 
 
 Rolfe and Haddock. Ibid., 25, 1015. 
 
 Krieger. Zeit. Spiritusind., 1894. 
 
 Archbold. J. Soc. Chem. Ind., 21, 4. 
 
MISCELLANEOUS SACCHARINE PRODUCTS 
 
 Milk Sugar. Milk sugar (lactose) is the only other biose 
 sugar which is produced in the free state in commercial 
 quantities. It is manufactured almost exclusively from 
 whey, usually obtained as the by-product of cheese factories 
 or other curd industries. Whey contains about 5 per cent 
 of lactose. 
 
 Lactose crystallizes in large rhombic crystals as the 
 monohydrate (C 12 H 22 O n H 2 O). These have little sweet- 
 ness; in fact, pure lactose is practically tasteless. It is 
 much less soluble than cane sugar or maltose, a solution 
 saturated at ordinary temperatures containing no more 
 than about 16 percent of it. Its specific rotation 1 is 52.5 
 at 20, almost identical with that of dextrose. This rota- 
 tion value is not affected by concentration, but is changed 
 considerably by temperature variations. Lactose has a 
 cupric-reducing power of .73. It is readily inverted by 
 hydrolytes into dextrose and galactose, the rotation of the 
 invert solution being increased to 67, the specific rotation 
 of galactose being 80. Concentrated solutions of lactose 
 after prolonged heating for several days become distinctly 
 sweeter in taste from the inverted products formed. Pure 
 milk sugar can be made by precipitation from its aqueous 
 solutions by means of alcohol. 
 
 1 After previously heating the freshly dissolved sugar to boiling. 
 
MISCELLANEOUS SACCHARINE PRODUCTS 223 
 
 The manufacture of milk sugar is commonly very crude, 
 consisting in evaporating the whey in open pans and at 
 the same time carrying on a clarification with alum. The 
 rough, dark, crystalline product, containing much mineral 
 matter, is redissolved, subjected to further clarification, and 
 after decolorizing with bone black is evaporated to a con- 
 centrated solution in a vacuum pan, and allowed to crystal- 
 lize gradually. 
 
 Three grades of milk sugar are found in commerce : 
 " cobs," cylindrical masses formed on wooden rods im- 
 mersed in the concentrated sugar liquors, which is the 
 purest kind; "plates," crystal sheets attached to the sides 
 of the tanks; and pulverized sugar, which is the common 
 form in which it reaches the consumer. This latter is 
 usually made from the loose deposit of crystals in the tank 
 bottoms by grinding, or the better quality from the " cobs " 
 or "plates." This pulverized sugar is dried in a kind of 
 granulator before it is packed. 
 
 The yield of milk sugar is only about 50 per cent, or, 
 at most, 60 per cent, of that contained in the whey, a con- 
 siderable loss of the sugar being due to the melassagenic 
 salts in the whey, which amount to nearly 15 per cent of 
 the sugar content, and in part to the crude methods of 
 preliminary extraction. 
 
 The ordinary refined milk sugar of commerce contains 
 usually over i per cent of mineral matter, but owing to the 
 fact that in drying it is partially dehydrated, samples often 
 polarize over 100 per cent if the sample is tested on the 
 saccharimeter, using the appropriate normal weight. 
 
 The normal weight of lactose (L) for any saccharimeter 
 obviously bears a ratio to the sucrose normal weight, 
 
224 MISCELLANEOUS SACCHARINE PRODUCTS 
 
 inversely proportional to the ratio of the specific rotations 
 of lactose and sucrose respectively. That is, 
 
 L :N=66.$ : 52.72 
 
 (52.72, according to Landolt, being the specific rotation 
 of lactose at 17.5 C). This gives 32.856 grams as the 
 normal weight for the standard half-shade saccharimeter 
 using Mohr cubic centimeter flasks, when the crystallized 
 lactose (monohydrate) is weighed, the solution being pre- 
 viously heated. 
 
 In the determination of lactose in milk, owing to the 
 bulk of the precipitate from the large amount of albu- 
 minoid matter present, volume correction must be made by 
 Scheibler's method of " double dilution " already described, 
 or the solution is made up to 102.6 cubic centimeters if the 
 normal weight, 26.048, is used. 
 
 Wiley recommends the use of an acid mercuric nitrate 
 solution for clarifying solutions, made by dissolving mer- 
 cury in double its weight of nitric acid and diluting with an 
 equal volume of water. Usually the milk is measured out 
 by a pipette, an equivalent of two or' three times the nor- 
 mal weight being taken. 1 About 3 cubic centimeters of 
 clarifying agent is used for the normal weight, the readings 
 being made as nearly at 20 as possible, as the specific rota- 
 tion of lactose varies appreciably by change of temperature. 
 
 Factory experiments have shown that the quality and 
 yield of milk sugar can be improved by application of 
 modern sugarhouse processes. 
 
 Determination of Lactose in Mixtures containing Maltose. 
 In many quasi-medicinal food preparations, maltose and 
 
 1 Wiley,/. Am. Chem. Soc.-iS, 428. 
 
MISCELLANEOUS SACCHARINE PRODUCTS 225 
 
 lactose are present. Boyden l has separated lactose from 
 maltose by recourse to the selective action of a yeast, Sac- 
 charomyce anomolus, which totally removed the maltose, 
 leaving the lactose unchanged. The lactose was then de- 
 termined by the Fehling method. 
 
 Honey. Pure honey is, in the main, invert sugar, usually 
 containing also a small quantity of sucrose, waxy matter, 
 and plant extractives. There are also traces of formic 
 acid in honey. The average constitution of sixty samples 
 of honey, according to Sieben, are : 
 
 Dextrose, 34-71 per cent 
 
 Levulose, 39-24 
 
 Sucrose, 1.08 
 
 Organic non-sugars, 5.02 
 Water, 19.98 
 
 Honey varies much in composition, according to the 
 food of the bees, as the insects will store up in the comb 
 sugar or glucose sirups in practically unchanged condition. 
 Such honey is usually considered as adulterated, just as 
 when such sirups are added directly to the product. The 
 chemical determinations of honey are solely directed to 
 ascertaining its genuineness as a product elaborated by 
 the bees from the blossoms. The amount of sucrose in 
 a honey rarely exceeds 2 per cent, although there are cases 
 of undoubtedly genuine honey containing more than 5 per 
 cent. Hence, the determination of sucrose, by the Clerget 
 method, is a valuable criterion, honey containing 10 per 
 cent or more of sucrose being unquestionably adulterated. 
 Lead acetate should be used in very small amount, if at 
 
 1 Ibid., 24, 993. 
 
226 MISCELLANEOUS SACCHARINE PRODUCTS 
 
 all, in clarification. Commercial glucose can be detected 
 usually by the same method. Advantage has been taken 
 of the temperature effect on the specific rotation of invert 
 sugar to detect adulteration by commercial glucose. 
 
 As already stated, the specific rotation of invert sugar 
 decreases by increase of temperature. This is caused by 
 the temperature effect on the levulose alone, its specific 
 rotation decreasing about .638 for every degree increase 
 in temperature. Authorities differ by some per cent as to 
 the exact value of the specific rotatory power of levulose, 
 which is approximately 93 at 20, this value being cor- 
 rect enough for the purpose. At about 88 an invert 
 sugar solution becomes optically inactive, owing to the 
 specific rotation of the levulose having decreased to 53, 
 and hence being just neutralized by the dextrorotatory 
 effect of the equal equivalent of dextrose whose specific 
 rotation is 53. 
 
 Chandler and Ricketts have utilized this property of 
 invert sugar to detect adulteration of honey and cane- 
 sugar sirups by commercial glucose. The sample of 
 invert sugar is heated in a jacketed tube to 87-88 by 
 means of a current of hot water (or, as originally, by 
 a heater in a saccharimeter specially designed by the 
 authors). 1 If only invert cane-sugar products are present, 
 
 1 The invert-sugar solution must be neutralized before heating to 87 to 
 avoid any hydrolysis of the glucose. Leach advises to make a separate solution 
 for this test, 26.048 grams of the sample in 70 cubic centimeters of water 
 to which 7 cubic centimeters of acid is added. The solution is inverted by the 
 usual Clerget process, almost neutralized with sodium carbonate or hydrate, 
 and made up to 100 cubic centimeters. If the ordinary commercial saccha- 
 rimeter is used, the hot tube must be in the instrument for as short a time 
 as possible to avoid serious errors from the heating of the saccharimeter. 
 
 Leach and Lythgoe find that the specific rotation of commercial glucose 
 
MISCELLANEOUS SACCHARINE PRODUCTS 22/ 
 
 the reading will be zero. If the reading shows the pres- 
 ence of commercial glucose, the amount can be approxi- 
 mated closely by taking the specific rotation as 130 and 
 calculating from the usual equations of optical rotation. 
 
 Wiley has devised a method for determining levtdose 
 on similar principles. He uses a saccharimeter specially 
 designed for reading solutions under different temperature 
 conditions, and determines the amount of levulose in 100 
 cubic centimeters by the standard saccharimeter readings, 
 the solution being made up so that there is approximately 
 the half normal weight of levulose in 100 cubic centi- 
 meters of solution. Two saccharimetric readings are 
 taken at temperatures about 50 apart. The levulose 
 present is then given by the following equation : 
 
 p TDf 
 
 Per cent levulose = 
 
 .035/0 -/')ze/' 
 
 where R R' is the difference in the reading, and tf 
 the difference in temperature, w f being the weight of sam- 
 ple dissolved, and .0357 the difference in reading caused 
 by one degree of temperature on i gram of levulose in 
 100 cubic centimeters of solution. 
 
 Maple Sugar. The carbohydrate of maple-sugar prod- 
 ucts is sucrose, and, consequently, the methods of analysis 
 of maple-sugar products are identical with those of cane 
 sugar. 
 
 at 87 is diminished about 7 % of its value at 20 (yyV) . Leach takes the 
 saccharimeter reading of the (sucrose) normal solution of commercial glucose 
 at 20 C. as 175. This corresponds to a 42 Be. commercial glucose [of a 
 specific rotation of about 138], which Leach has found to be representative 
 of " mixing " glucose. At 87, the saccharimetric reading was found to be 
 163. 
 
228 MISCELLANEOUS SACCHARINE PRODUCTS 
 
 The fact should not be lost sight of, however, that what 
 gives maple sugar its intrinsic value are the pleasantly 
 flavored plant extractives. 
 
 If maple sugar is refined, it becomes nothing more than 
 ordinary granulated sugar, and no more valuable. Stimu- 
 lated by the government bounties of previous years, which 
 were based on the sugar content, the maple-sugar pro- 
 ducers have worked to obtain light-colored sugars with high 
 sucrose content, but which are really inferior to the cruder 
 products on the flavor of which the true value of the sugar 
 depends. This custom of valuing maple sugar solely on 
 its sucrose content has led unscrupulous manufacturers to 
 adulterate the product with cane sugar. It would seem 
 better to base the valuation of maple sugar on a ratio of 
 plant extractives characteristic of the maple to the sucrose 
 content, in addition to the sucrose content alone. 1 
 
 Maple sirup, so called, is often manufactured from com- 
 mercial glucose, cane sirups, and an extract made from 
 hickory bark or corncobs. 
 
 Confectionery. The kinds of confectionery are so vari- 
 ous that it will be impossible in the space at hand to 
 describe more than the general characteristics of some 
 common products. In general, candy is an " amorphous " 
 substance, that is, it does not tend to take definite crystal 
 line form, but can be molded to any shape desired. Cane 
 sugar tends to crystallize under almost every condition in 
 
 1 See Hortvet (/. Am. Chem. Soc., 26, 1523), who bases his tests for adul- 
 terants on the volume of the precipitated organic matter and the malic acid 
 content. Hill and Mosher have suggested a somewhat similar method. Jones 
 determines the characteristics of the ash. Manganese is said to be a charac 
 teristic of maple-sugar ash. This characteristic is probably dependent on loc"l 
 soil conditions, however. 
 
MISCELLANEOUS SACCHARINE PRODUCTS 22Q 
 
 concentrated solution, unless strongly melassagenic bodies 
 are present, but by melting sucrose crystals at 160, and 
 allowing them to solidify, an amorphous form, "barley 
 sugar," is produced, which, however, gradually becomes 
 crystalline. If, however, a sugar solution is partially 
 inverted, the highly concentrated residue will remain 
 imorphous. Hard candies were originally made by boil- 
 ing sugar with some inverting agent, commonly cream of 
 tartar or tartaric acid. 
 
 Other materials, as gums and clay, have been used in 
 soft candies to " cut the grain " or prevent crystallization. 
 " Fondants," used so much in chocolate creams and bon- 
 bons, are made by slightly inverting a concentrated solu- 
 tion of granulated sugar with cream of tartar, and then, 
 when the mass is of the right concentration, as shown by 
 its temperature (about 255 F.), pouring it upon a cold 
 slab, and beating up the mass till it cools. In this way a 
 paste of fine floury crystals is formed, which remains for a 
 long time in this condition if properly made, owing to the 
 crystals becoming coated with invert sugar sirup, which 
 prevents further growth. 
 
 In modern candy making, commercial glucose has been 
 found to be an ideal material for " cutting the grain," since 
 the 20 per cent or more of dextrin contained in it is strongly 
 melassagenic, and prevents the crystallization of several 
 times its weight of sugar. Glucose, moreover, is a health- 
 ful sweet, which can be obtained cheaply in great purity. 
 Hence it is almost a universal constituent of manufactured 
 candies. 
 
 A large class of candies of a soft rubbery nature, like 
 " jujube" and other pastes, cheap gumdrops, and the like, 
 
230 MISCELLANEOUS SACCHARINE PRODUCTS 
 
 are made by boiling commercial glucose, diluted to about 
 35 Be., for about three hours with 20-30 per cent of its 
 weight of starch with a little tartaric acid, or, preferably, 
 using thin-boiling starch. This class of confectionery is 
 known as " AB goods." " Marsh mallows " are made from 
 gelatin beaten up with glucose and starch. 
 
 Aside from the determination of coloring matters, flavor- 
 ings, and other obvious non-sugars which may cover nearly 
 every process of food analysis, the principles of sugar 
 analysis given in the previous chapters can be applied to 
 determining the composition of candies in general. The 
 Clerget method will give a close approximation to the 
 unaltered cane sugar, the principal error being a small 
 one caused by the hydrolyzing action of the inverting 
 acid on the glucose and other starch products. By deter- 
 mination of the specific rotation of the separated carbo- 
 hydrate matter, an equation can be formed in which the 
 effect of the sucrose is known and the glucose and invert 
 sugar expressed as unknown quantities. For instance, let 
 5 be the per cent of sucrose determined by double polari- 
 zation, and expressed as a percentage of the total carbo- 
 hydrate, x being the per cent of glucose and y being the 
 per cent of invert sugar. 
 
 Then, x-\-y 5= per cent of unknown carbohydrate 
 
 135^-937 + 66.5 S=a 
 
 (135 being the average specific rotatory power of the 
 carbohydrate of commercial glucose). 
 
 From these equations, the proportion of sucrose (5) 
 being known, the invert sugar and commercial glucose 
 carbohydrate can be determined with sufficient accuracy 
 
MISCELLANEOUS SACCHARINE PRODUCTS 231 
 
 for most commercial requirements. If starch is present 
 in a conversion state much less advanced than glucose, it 
 may be necessary to determine the invert sugar directly, 
 and after obtaining the total weight of carbohydrate, 
 determine the per cent of starch product by difference. 
 The specific rotation of the starch product obtained by 
 calculation by such methods will be indicative of the 
 amount that the starch has been changed in the making 
 of the candy, and therefore instructive of the process of 
 manufacture. 
 
 No definite rules of procedure can be followed in the 
 investigation of candies, as they differ so widely in com- 
 position and properties. In any attempt to get at the 
 component carbohydrates, it is obviously necessary to 
 eliminate other material by the usual processes of proxi- 
 mate food analysis. Much organic material of the nature 
 of albumen can be removed by basic lead acetate, but 
 owing to its influence on carbohydrates other than sugar, 
 especially starch products and invert sugar, it is better 
 replaced in most cases by aluminum hydrate mixture. If 
 the carbohydrate is determined by the density, after other 
 organic matter has been removed, ash corrections must be 
 made on the solutions. 
 
 It is clear, as in most proximate analyses of complex 
 commercial products, that such investigations of the com- 
 position of a candy do not admit of high accuracy, but 
 they do in many cases throw sufficient light on its make- 
 up to be of much value, in fact, to meet all purposes of 
 such work. 
 
 Effective application of the many methods of sugar 
 analysis will usually enable the well-informed chemist to 
 
232 MISCELLANEOUS SACCHARINE PRODUCTS 
 
 get the desired information in most cases, however compli- 
 cated the confection. 
 
 Jellies and Preserves. Leach 1 uses the following method 
 for approximately determining the sugars in jellies, pre- 
 serves, and similar preparations : 
 
 When commercial glucose is known to be absent, and 
 the sugars consist of sucrose and the invert sugar resulting 
 from the former by the cooking processes of manufacture, 
 a double polarization is made by Clerget's method, the su- 
 crose being calculated by the usual formula : S = 
 (see footnote, p. 108). 
 
 Inasmuch as the actual numerical value of b, the reading 
 of the (saccharimetric) normal solution after inversion by 
 the Clerget method, is due to the sum of the invert sugar 
 originally present in the sample and that made by the 
 Clerget process, the ratio of the reading b to the reading 
 of a normal solution of pure sugar completely inverted by 
 this process will express the per cent of sucrose (S f ) in 
 the sample, previous to any inversion in the process of 
 manufacture. (This per cent, of course, is that of the 
 finished product, not of the total weight of the original 
 ingredients which have been changed in manufacture.) 
 
 Hence, S' = , since 44 + .5 t gives the reading 
 
 44+. 5 t 
 of a (saccharimetric) normal solution completely inverted 
 
 by hydrochloric acid. The per cent of invert sugar (/) 
 actually existing in the manufactured product as such can 
 be determined, according to Leach, by the following equa- 
 tion : / == I 5-3(^-^). (The factor, 105.3, which is the 
 
 44 + -5 t 
 
 1 Leach, " Food Inspection and Analysis." The form of Leach's equations 
 are changed here. 
 
MISCELLANEOUS SACCHARINE PRODUCTS 233 
 
 equivalent of invert sugar formed from 100 parts of su- 
 crose, must be used because the value l 44 -f . 5 / cor- 
 responds to the invert sugar derived from 26.048 grams of 
 sucrose, and not to 26.048 grams of invert sugar already 
 formed.) 
 
 When commercial glucose is present, Leach determines 
 the amount of this ingredient by polarizing the normal 
 weight of sample at 87 as described on page 226 (see 
 also footnote, p. 226). 
 
 Assuming that the saccharimetric reading of a commer- 
 cial glucose solution, 26.048 grams in 100 cubic centimeters 
 at 87 C, is 163, since the invert sugar at this temperature 
 is optically inactive, the per cent of glucose (G) can be 
 
 a* 
 
 found by the equation, G -~-, where g is the reading at 
 
 87. From g the reading g 1 of the corresponding amount 
 of glucose at the laboratory temperature (20) can be cal- 
 culated by Leach's factor, -^f, and the invert sugar in the 
 
 sample by the equation,* Im lOS 
 
 44 .5 / 
 
 It is obvious that errors may be introduced by the heat- 
 ing of the saccharimeter in taking readings at 87 if special 
 care be not taken, or a specially constructed instrument be 
 used. 
 
 A definite saccharimetric value is assumed for glucose 
 which is, as has been shown, a product variable in its 
 composition as well as in water content. The glucose ma) 
 
 1 This value is not strictly correct, as it applies to the rotation of an inverted 
 sucrose solution in the presence of hydrochloric acid which increases the sac- 
 charimetric reading. The reading a is taken before adding the inverting acid. 
 
 2 A simpler equation would seem to be : 1= 105.3 I a ~^~s \ . 
 See footnotes on pp. 107 and 108. \ 4 2 +-5*/ 
 
234 MISCELLANEOUS SACCHARINE PRODUCTS 
 
 change during the manufacture of many of these products, 
 the change in the main being a partial dehydration. If 
 the dehydration be sufficient to reduce the water content 
 of the product below that in the original glucose (about 
 20 per cent), it is clear that the glucose rotation will be 
 changed proportionately to the (practically anhydrous) 
 sucrose and that the assumed saccharimetric value of 175 
 will not apply for such goods. 
 
 Hence, when it is possible to remove the organic matter, 
 not carbohydrate, by suitable clarification methods, a pro- 
 cedure based on the density method previously described 
 would appear to be more accurate, as errors due to dis- 
 solved mineral matter can be eliminated by the ash correc- 
 tion already described. Values calculated from the specific 
 rotation of the anhydrous substance are not affected by 
 variation which may have taken place in the water content 
 of the product. 
 
 The per cent of total solids in the sample can be obtained 
 with sufficient exactness for calculating the proportions of 
 carbohydrates in terms of the original weight of sample, 
 the glucose being assumed to have been originally an 80 
 per cent solution. If the weight of total carbohydrates 
 can be calculated, reading at 87 is unnecessary for deter- 
 mining the glucose (see p. 230). Of course, as in Leach's 
 procedure, the specific rotation for the anhydrous glucose 
 must be assumed. 
 
 Hydrolyzed Products of Cellulose. Ever since 1819, 
 when Braconnot exhibited sugar made from linen rags 
 at a meeting of the French Academy, cellulose has been 
 considered as a possible material for sugar production, 
 but, until recently, attempts to manufacture sugar or gums 
 
MISCELLANEOUS SACCHARINE PRODUCTS 235 
 
 from wood waste economically have given yields so low as 
 to be of no practical value. It is, nevertheless, easy to 
 repeat Braconnot's work, which consisted in treating the 
 linen with about twice its weight of sulphuric acid till the 
 whole mass became a paste, and, after diluting with water 
 to about a 2 per cent solution, heating for ten hours. The 
 neutralized solution on evaporation yielded dextrose. Any 
 attempt at more economical production, by increasing the 
 proportion of cellulose and decreasing acid, results in an 
 insignificant yield. The practical difficulty seems to lie in 
 the formation of insoluble intermediate products, analogues 
 of dextrin, which are only broken up by large excess 
 of acid. The small amount of soluble product formed is 
 optically active, its specific rotation being usually about 
 40, the cupric reduction about .90 as found in experiments 
 in hydrolyzing cotton with sulphuric acid. 1 This corre- 
 sponds to a mixture of xylose (a pentose sugar of specific 
 rotation of 19.2, and cupric-reducing power of i.io)with 
 dextrose, but the data at hand are not complete enough to 
 be conclusive. Cross and Bevan have experimented con- 
 siderably on the hydrolysis of cereal straws, and also find 
 pentose sugars. 
 
 Comparatively recently, Claassen has patented processes 
 for conversion of cellulose into fermentable sugar by which 
 a large yield is claimed. The unique and vital feature of 
 the process is the conduct of the hydrolysis under mechani- 
 cal pressure, subjecting a mass of sawdust moistened with 
 sulphuric acid to the action of a press. This is said to give 
 soluble saccharine product in large amount, which can be 
 utilized in the economic production of alcohol. 
 
 1 Tech. Quart,, 12, 51. 
 
236 MISCELLANEOUS SACCHARINE PRODUCTS 
 
 Sugar in Urine. In certain diseases the urine is found 
 to be charged with sugar, often in very large quantities. 
 This sugar is probably dextrose, although there is evi- 
 dence tending to show that levulose and other sugars 
 may be present. The determination of sugar in the urine 
 is, therefore, of much pathological importance, especially 
 as normal urine contains none or but occasional minute 
 quantities. 
 
 The polariscope can be used for testing urine to a great 
 extent, in the advanced stages of disease, as the sugar 
 content, determined as dextrose, may amount to as much 
 as 10 grams in 100 cubic centimeters. The polarimetric 
 values are not, however, absolutely accurate, as normal 
 urine often has a slight negative rotation, corresponding 
 to a reading of from .3 to .8. According to Carles, 1 
 this is caused by a complex amine compound called 
 "creatinin." The urine is filtered and polarized directly 
 in a 2-decimeter tube. If colloidal albuminoids are 
 present, which make the filtrate turbid, and which are 
 themselves slightly optically active, they must first be 
 removed by adding a few drops of acetic acid and heat- 
 ing the urine nearly to boiling. If the urine is very dark 
 and turbid, the usual clarifying agent, basic lead acetate, 
 can be used. In this case allowance must be made for the 
 change in volume caused by the addition of the clarify- 
 ing agent ; conveniently by the use of the double-marked 
 flask, as already described in discussing quotient of purity 
 determinations. 
 
 If the commercial saccharimeter is used for the test, the 
 dextrose, customarily expressed in grams in 100 (Mohr) 
 
 1 Jour, de Pharrn., 1890, 108. 
 
MISCELLANEOUS SACCHARINE PRODUCTS 237 
 
 cubic centimeters, can be calculated from the following 
 
 RN' 
 formula, W= - , where N f is the normal weight of the 
 
 instrument for dextrose. As the normal weights for su- 
 crose and dextrose are obviously inversely proportional to 
 their respective specific rotations, the dextrose normal can 
 be easily calculated. Owing to the effect of the solvent 
 on the specific rotation of dextrose, the dextrose normal 
 weight is slightly different at different concentrations, the 
 specific rotation being expressed by the formula, 
 
 For the standard commercial saccharimeter, having the 
 sucrose normal weight of 26.048 grams, the formula for 
 
 TT7 32.91 R 
 urine analysis becomes W = - 
 
 100 
 
 Saccharimeters, both of the rotating and the quartz com- 
 pensation types, are made specially for urine analysis, and 
 are graduated to read directly in grams of dextrose in 100 
 cubic centimeters. As these instruments do not differ in 
 essential characteristics from the standard types, details 
 are unnecessary. 
 
 Copper reduction methods also apply to sugar determi- 
 nations in urine, providing it is fresh. If the urine is 
 ammoniacal, obviously the modified volumetric method of 
 Pavy must be used, as the precipitated cuprous oxide of 
 the Fehling processes will be dissolved more or less by the 
 ammonia. 
 
APPLICATION OF THE POLARISCOPE IN 
 SCIENTIFIC RESEARCH 
 
 Laws of Optical Isomerism. In the opening chapter, 
 reference was made to the important theory relating optical 
 activity to chemical structure which was developed by two 
 independent workers, Van't Hoff and Le Bel. Only an 
 outline of the more important general laws developed from 
 this theory, that may be necessary for a comprehension of 
 the chapters following, will be given here. 
 
 Theoretically, any substance showing optical activity 
 can exist in at least three isomeric forms : one which is 
 dextrorotatory ; another of equal rotation value but left 
 rotating ; and the third, a chemical compound of equal 
 equivalents of the dextro- and levorotatory isomers ; this 
 last being optically inactive and termed the "racemic" 
 form. By the Van't Hoff-Le Bel theory, the laws relating 
 the molecular structure of these isomeric forms to their 
 optical activity can be expressed by the following graphical 
 symbolism, which is derived from that commonly used to 
 nterpret the chemistry of carbon compounds. 
 
 Most optically active substances can be symbolized by 
 one of three schemes of configuration. The first can be 
 generalized in the form, R C a b R f , R and R J repre- 
 senting unlike terminal radicals, and C any number (n) of 
 carbon atoms, each carrying the unlike radicals, a and b y 
 
 238 
 
THE POLARISCOPE IN SCIENTIFIC RESEARCH 239 
 
 and connected to these two terminal radicals in a continuous 
 chain. The number of different symbolic images which 
 can be made by varying the arrangement of the univalent 
 radicals a and b attached to the intermediate carbon atoms 
 (C) determines the number of isomers theoretically possible. 
 
 Those figures symbolize optically active isomers which 
 show an arrangement of a and b not symmetrical (" asyiL. 
 metrical") to the carbon chain; that is, if the -figures arc 
 divided along the median line of the carbon chain, or 
 bisected horizontally, the two halves are not identical. 
 Such figures can be grouped in pairs which represent 
 arrangements of a and b making mirror images of each 
 other x ("enantiomorphic"). The images so related typify 
 isomers which have many physical and chemical properties 
 in common, but which rotate the polarized rays equally in 
 opposite directions. Such isomers are said to be " antip- 
 odal " to each other. 
 
 In this specific scheme of configuration, R C a b R* ', 
 figures which show symmetrical distributions of a and b 
 on each side of the median carbon line also represent 
 optically active substances, there being no representation 
 of optically inactive bodies ; for owing to the unlike termi- 
 nal radicals, the figure halved horizontally would still be 
 asymmetrical. Actually, all bodies not racemic whose prop 
 erties can be interpreted by this graphical representation 
 have been found to be optically active. 
 
 The following symbols of the possible isomers of ai\ 
 optically active body containing five radicals, three of which 
 
 1 The assumption is made, of course, that a and b are. each represented in 
 the figure by some symmetrical character, as for instance a by a dot and b by 
 a circle. 
 
240 THE POLARISCOPE IN SCIENTIFIC RESEARCH 
 
 are " asymmetric carbon atoms," will illustrate the manner 
 of predicting the optically active isomers : 
 
 a C b b C a 
 
 a C b b C a a C b b C a a C b b C a b C a a C b 
 R J R' R' R 1 R' R 1 R 1 R' 
 
 Those which are paired as representing "antipodes" which 
 can form racemic compounds are joined by brackets. 
 Consequently, four racemic isomers are possible in com- 
 pounds represented by this scheme which contain five 
 carbon atoms. 
 
 By the mathematics of permutation and combinations 
 the possible number of optically active isomers (N) which 
 can exist according to such a scheme can be computed by 
 N= 2 n , where n represents the number of " asymmetric car- 
 bon atoms" expressed by Cm the formula, R C a b R '. 
 
 All the hexose (glucose) sugars as well as the pentose 
 and other carbohydrates can be represented in this scheme. 
 For instance, from an elaborate investigation of dextrose 
 ([a]/>= 52.7), Fischer has symbolized this sugar: 
 
 CH 2 OH 
 HO C H 
 HO C H 
 
 H C OH 
 HO C H 
 
 CHO 
 
 According to theory, a levorotating isomer should exist 
 whose structure can be symbolized by a figure the mirror 
 image of this. Fischer actually isolated a left-rotating 
 
THE POLARISCOPE IN SCIENTIFIC RESEARCH 241 
 
 sugar which has many of the properties of dextrose and a 
 specific rotation of --51.4. Likewise, many other antipo- 
 des of this group have been isolated or made synthetically, 
 so that of the sixteen isomers of the simple hexose sugars 
 theoretically possible according to the equation N = 2 n , a 
 dozen or more are known. 
 
 The second scheme of configuration for graphically rep- 
 resenting the chemical structure of optically active com- 
 pounds is expressed as R C a b R, where the terminal 
 radicals are alike and the carbons expressed by C, to which 
 the two radicals determining optical activity are attached, 
 
 ?,-i 
 are even in number. In this scheme, N= 2 n ~ l + 2* , of 
 
 5-1 
 
 which 2 n ~ l represent optically active isomers, since 2 2 
 
 figures, having symmetrically distributed a and b groups 
 relative to the two like terminal radicals (as shown by 
 dividing such figures in halves horizontally) are optically 
 inactive. 
 
 Tartaric acid is typical of this group. The symbolic 
 representation of this acid shows two "asymmetric carbon " 
 groups. Hence there are two possible optically active 
 isomers and one inactive. These can be represented by 
 the following symbols : 
 
 COOH COOH COOH 
 
 HO C H H C OH H C OH 
 
 H C OH HO C H H C OH 
 
 COOH COOH COOH 
 
 The first two are antipodes, in combination forming the 
 optically inactive racemic acid. The third (mesotartaric 
 acid) is the inactive isomer, as predicted by the equation. 
 
242 THE POLARISCOPE IN SCIENTIFIC RESEARCH 
 
 The third scheme of configuration representing the 
 isomerism of the remaining compounds which can be 
 symbolized by a representation of a chain of carbon nuclei, 
 is identical with the second except that the number of car- 
 bon atoms determining the asymmetric groupings (n) is odd. 
 In this scheme the figure can be halved horizontally on 
 each side of a middle carbon group. When the grouping 
 of the radicals expressed by a and b is symmetrical rela- 
 tive to this middle carbon, the isomer is optically inactive. 
 The total number of optically active isomers (N) is, in this 
 case, N= 2 n ~ l , the number of optically active being ex- 
 pressed : --i 
 A = 2 n ~ l - 2 2 . 
 
 n-l 
 
 The inactive isomers obviously are expressed by /= 2 2 . 
 Trioxyglutaric acid is an example of this class. 
 
 While the examples cited have to do with arrangements 
 of hydrogen and hydroxyl radicals, similar arrangements 
 of other radicals also represent optical activity, the essen- 
 tial being the "asymmetric carbon" nuclei which permit 
 of configurations which are mirror images of each other. 
 So, too, optically active bodies exist whose chemical struc- 
 ture can be explained by the ring representation, character- 
 istic of the so-called aromatic compounds. These can be 
 demonstrated satisfactorily only by a solid figure, three 
 dimensions being necessary. The asymmetric carbons in 
 such figures are best represented as tetrahedra. It will 
 suffice to state here that when the substance is represented 
 by a ring structure and only one asymmetric carbon is 
 present, there are three isomers, two of which are 
 antipodes, and the third is the corresponding racemic 
 compound, Many constituents of the essential oils, as 
 
THE POLARISCOPE IN SCIENTIFIC RESEARCH 243 
 
 pinene, limonene, and camphene, are represented by this 
 configuration. 
 
 If two asymmetric carbons are in the ring configuration, 
 there are two possible antipodes and their corresponding 
 racemic forms. There are also a few instances in which 
 optical activity can be explained by figures containing 
 asymmetric nitrogen or sulphur. 
 
 In natural products, as a rule, only one or the other 
 antipode of an optically active substance is found, rarely 
 the racemic combination. In fact, racemic forms of many 
 optically active substances, as starch, are unknown. On 
 the contrary, all bodies ordinarily optically active in the 
 natural state are inactive when made by synthesis from 
 inactive substances. This is due to the formation of equal 
 equivalents of the antipodes and consequent racemic com- 
 binations. In order to separate the antipodes of such syn- 
 thetic compounds, many ingenious chemical and physical 
 methods are resorted to. 
 
 Antipodal substances show identical physical and chemi- 
 cal characteristics when isolated or in chemical combination 
 with optically inactive substances, if certain crystalline 
 and electric peculiarities (also, in some cases, physiological 
 effects) are excepted. 
 
 If, however, antipodal substances are combined with an 
 optically active body, there is often a noticeable change in 
 the properties of the compounds formed by each antipode. 
 In this manner, many racemic compounds made by syn- 
 thesis have been resolved into these antipodes. The alka- 
 loids have proved valuable in these separations, since, 
 owing to the difference in solubility of many antipodal salts 
 formed by combination with these bases, many isomers 
 
244 THE POLARISCOPE IN SCIENTIFIC RESEARCH 
 
 can be separated by precipitation. By combinations with 
 the alkaloids, strychnine, morphine, brucine, and cinchonine, 
 Fischer was enabled to obtain optically active dextrose 
 and its levo-isomer from the optically inactive racemic 
 body synthesized from acrose. 1 
 
 Antipodal isomers have also been separated by the action 
 of some of the lower vegetable organisms as certain molds, 
 yeasts, and bacteria, also many of the enzyms which 
 show selective action in destroying one antipode. Fischer 
 showed that the yeasts, as a rule, attacked the naturally 
 occurring dextrorotatory forms of dextrose, maltose, and 
 mannose, but did not ferment the levo-isomers separated 
 by synthetic processes. On the contrary, levulose was 
 attacked, but not its dextro-isomer. 
 
 Determinations of Specific Rotatory Power. In the ex- 
 planation of specific rotatory power, previously given, only 
 an allusion was made to the disturbing effects of solvents 
 and temperature which occur in the case of many com- 
 pounds, as these influences on the sugars heretofore 
 discussed are so slight as to be of little importance in 
 most commercial analysis. Invert sugar and the tempera- 
 ture influence on milk sugar are excepted, temperature 
 coefficients of which have been given. 
 
 Since the specific rotations of the ray of standard wave 
 length caused by many substances, when calculated from 
 solutions of different concentrations and from those in 
 different solvents, do not give constants, it is customary 
 in practical work to calculate such values from solutions 
 made from the specified solvent containing 10 grams of 
 substance in 100 cubic centimeters (or what is usually 
 
 1 Ber. d. ckem. Ges., 23, 370, 799, 2133; 2 5 I2 55- 
 
THE POLARISCOPE IN SCIENTIFIC RESEARCH 245 
 
 sufficiently identical for this purpose, a concentration of 
 10 per cent), readings being taken at 20 to eliminate any 
 temperature disturbance. 
 
 To eliminate the influence of the solvent, the so-called 
 " absolute " specific rotation of an optically active sub- 
 stance is often calculated. Biot, in investigations begun in 
 ^838, and extending over twenty years, showed that this 
 could be obtained by plotting curves representing the 
 variations in the apparent specific rotation calculated from 
 different concentrations of solution, each solvent giving an 
 independent curve. If the per cent of solvent in each 
 solution polarized is plotted as an abscissa, and the corre- 
 sponding value of the apparent specific rotation as an ordi- 
 nate, a curve is made which is either a straight line or can be 
 considered a hyperbola or parabola. If the line is straight, 
 the absolute specific rotatory power can be expressed by 
 the formula a = A -f Bq, where q is the per cent of sol- 
 vent present, and the constants A and B calculated from 
 the plots, A being the absolute specific rotation, B the rate 
 of its change with the quantity of solvent present. If 
 the line is a curve, the equation [a]/> = A + Bq + Cq 2 is 
 sufficiently correct for practical purposes in the majority 
 of cases. If the per cent of active substance is expressed 
 by p, the equations become [a] /) = A + B(ioo /) and 
 [IL] D = A + (ioo /)+ C(ioo /) 2 . 1 
 
 In the equation [a] jD = A + Bq + Cq*, the constants B 
 and 7 can be obtained by determining the apparent specific 
 rotations from three solutions of different concentrations : 
 
 1 So, too, pd can be substituted for/, giving the equation for concentration 
 expressed as As the density influence of most substances in solution is 
 not a constant, however, such equations are not precise. 
 
246 THE POLARISCOPE IN SCIENTIFIC RESEARCH 
 
 [a] n = A + B 9l + Cqf. (I) 
 
 [*\H = * + Bq*+ Cqf. (2) 
 
 [aU^ + .ffft+Cft* (3) 
 
 If (2) is subtracted from (i) and (3) from (2) : 
 
 l>] B I - M 2 = *(ft - ft) + C(ft a - ? 2 2 > (4) 
 
 [ata - |VU = B(q t - ft) + C(<7 2 2 - ft*). (5) 
 
 From (4) B = M*" M** 
 
 ft- ft 
 
 ft-ft 
 
 From (5) B = M^-IXU _ ^ + ^ 
 
 Hence : C= , Mi" E<U _ I>L* ~ M* 
 
 Landolt has proved by experiment, in the case of a large 
 number of optically active substances, that the value A, 
 determined mathematically by Biot's formulae, represents 
 the true or absolute specific rotation. 
 
 The example most cited is that of oil of turpentine. If 
 the specific rotation of this substance is determined directly 
 by polarizing the pure oil, free from solvent, the specific 
 
 rotation, calculated from the formula a = y^ is 14.15. If 
 
 Let 
 
 the specific rotation values are obtained from alcoholic 
 solutions of various concentrations, the values increase 
 with the dilution, an 80 per cent solution having a specific 
 rotation of about 14.4, a 20 per cent about 15.2. The 
 plotted values obtained at different concentrations form a 
 
THE POLARISCOPE IN SCIENTIFIC RESEARCH 247 
 
 straight line, which is represented by the equation [a]/> = 
 14. 17 + .00178 q, A in this case being identical within 
 experimental error with the value actually obtained by 
 polarizing the pure oil, free from solvent. 
 
 In cases where it is impossible to polarize the substance 
 free from solvent, as in the case of camphor or tartaric 
 acid, plots made by dissolving the substances in different 
 solvents give curves which, while of different forms, all 
 converge to a common focus, which expresses the com- 
 mon value of A obtained in each equation. In some cases 
 these curves show an increase in apparent value of the 
 specific rotation with dilution, as in the case of oil of tur- 
 pentine and tartaric acid ; in others a decrease, as those of 
 camphor and tartaric acid. Nicotine in dilute water solu- 
 tions is peculiar in giving a curve which gradually decreases 
 with dilution to a minimum at about 8 per cent, and then 
 increases. Camphor shows the same minimum value with 
 some solvents. Malic acid and its sodium salts show 
 even a reversal of the direction of rotation at certain 
 concentrations. 1 
 
 The temperature effects on the specific rotations of 
 optically active solutions have not been formulated except 
 in comparatively few instances. 
 
 The rotation of a mixture of optically active substances 
 in solution, when these substances do not react upon each 
 other, is the resultant of their individual rotatory effects, 
 as has been proved by many experiments. Acids, alkalies, 
 and many salts influence the rotatory effects of optically 
 
 1 See Landolt's " Optische Drehungsvermogen " for a complete account of 
 the researches on specific rotation. See also, on tartrates, E. B. and F. B. 
 Kenrick, /. Am. Chem. Soc., 26, 665. 
 
248 THE POLAR1SCOPE IN SCIENTIFIC RESEARCH 
 
 active bodies, but in most cases present knowledge is 
 insufficient to show whether in certain cases chemical 
 action takes place or not. Apparently in some cases 
 polymerization affects optical rotation, although many 
 experiments, as those with itaconic acid, 1 show the 
 opposite. 
 
 A large and attractive field of research in physical chem 
 istry is opened and yet but little worked in optical investiga- 
 tions of molecular structure by means of the polariscope. 
 The only line which has been followed up in this direction 
 to any extent has been that pointed out by the researches 
 of Pasteur and Van't Hoff. 
 
 Attempts have been made to apply the theory of elec- 
 trolytic dissociation to optically active solutions containing 
 salts, acids, and bases ; and the investigations of Oudemans 
 and later Hadrich 2 on alkaloids have established the fol- 
 lowing law : the rotating power of electrolytes in general 
 in dilute solutions, where the dissolved substance is largely 
 dissociated into its ions, is independent of the inactive 
 constituents of the salt. For instance, different quinidine 
 salts diluted to the extent of a "gram equivalent" (the 
 molecular weight in grams) in 20 liters of water or more, 
 show identical rotation values which gradually increase 
 up to a dilution of the gram equivalent in 80 liters 
 being constant at greater dilutions. The salts of mor 
 phine behave in a similar way, as do those of brucine 
 and strychnine, although the specific rotation becomes 
 constant in the case of the two latter alkaloids at lower 
 dilutions. 
 
 1 Walden, Zeit.phys. Chem., 20, 383. 
 
 2 Hadrich, Ann. Chem. Liebig, 207, 257. 
 
THE POLARISCOPE IN SCIENTIFIC RESEARCH 249 
 
 Molecular Specific Rotation. In calculations of the rota- 
 tory effect of the molecule in physical chemistry, the 
 "molecular rotation" (symbolized, M) is sometimes used 
 as the optical unit. This is obtained by multiplying abso- 
 lute specific rotation by the molecular weight of the sub- 
 stance. Usually for convenience T ^ of this unit is taken 
 (symbol, [M~]). 
 
 Many attempts have been made to establish laws which 
 would express the influence of molecular structure on rota- 
 tion values, but with little success, the Van't Hoff-Le Bel 
 theory being still incomplete on these lines, as shown by 
 the work of Guye, Walden, and others. The principal law 
 which does hold good is one of Van't Hoff that if a com- 
 pound contains several "asymmetric" carbon atoms and 
 consequently several optically active groups, the rotation is 
 the algebraic sum of the group rotations. This has been 
 found to be exactly true by the work of Guye l and Walden 
 on the liquid amyl esters, and is of vital importance, as on 
 its establishment depends the correctness of the whole 
 theory of isomeric sugars as developed by Fischer, as well 
 as the methods of investigation of hydrolyzed starch com- 
 pounds already explained. 
 
 Multirotation ("birotation "). Many sugars when freshly 
 dissolved and polarized give initial temporary rotation 
 values which gradually change and become constant after 
 some hours. This phenomenon was first observed by 
 Dubrunfaut, in 1846, in dextrose solutions. This transi- 
 tion condition of the specific rotation has since been found 
 to exist in many sugars and other compounds as well, as 
 in oxyacids and their lactones, nicotine, and some amine 
 
 1 Guye, Compt. rend^ 121, 827. 
 
250 THE POLARISCOPE IN SCIENTIFIC RESEARCH 
 
 bodies. The optical values may increase or decrease 
 toward a constant, and some sugars form two optically 
 unstable or " labile " modifications, according to the condi- 
 tions of their extraction from concentrated solutions. Both 
 these forms revert to the stable condition at a rate depend- 
 ent on the presence of any catalytic bodies which hasten 
 the change ; the laws of the rate of hydrolytic change of 
 Wilhelmy and the principle that the influence of the acids 
 was proportional to their " affinity constants " applying 
 generally. Alkalies, even in very dilute solutions (.1 per 
 cent ammonia, for instance), produce an almost immediate 
 change of rotation to the constant value, and by prolonged 
 action at greater concentrations produce changes in ro- 
 tations of many of the sugars which can only be explained 
 by the formation of new compounds. Lobry de Bruyn 
 and Van Ekenstein have shown that this is due to the 
 formation of isomeric sugars rather than phenomena of 
 multirotation. 
 
 Bringing the optically active solution to a boil gives the 
 constant rotation value, for the optical transition, analogous 
 to hydrolytic change, is enormously accelerated by tempera- 
 ture increase. As already noted, this latter procedure of 
 heating the solution is necessary in analytical operations, 
 as, for instance, when dealing with freshly dissolved milk 
 sugar or dextrose. Cane sugar shows no multirotation. 
 The monohydrate of dextrose, which is the form which 
 commercial " grape sugar " takes, shows multirotation simi- 
 lar to the anhydride. 
 
 The following table shows the specific rotations of 
 the labile and stable forms of the more important 
 sugars : 
 
THE POLARISCOPE IN SCIENTIFIC RESEARCH 251 
 
 Dextrose. . . . 52.7 105.2 22.5 
 
 Galactose . . . 81.6 135.0 52.3 
 
 Lactose .... 52.5 86.2 34.4 
 
 Maltose .... 138.0 118.2 
 
 Levulose ... - 92.5 - 104.0 
 
 Arabinose 1 . . . 104.4 156.7 
 
 Xylose 1 .... 19.2 94-4 
 
 a is the labile solution made by dissolving the crystallized 
 sugar in water ; (3 the stable solution ; -y a second unstable 
 form, usually produced by heating the residue evaporated 
 from solution, or by precipitation with alcohol. 
 
 Multirotation seems to be a phenomenon resulting from 
 hydration of the substance, accompanied by a rearrange- 
 ment of the optically active groups, but it has not been 
 completely explained. 
 
 Laws of Hydrolytic Change. The polariscope has been 
 of great service to science as a means of measurement of 
 comparative chemical activity of hydrolyzing substances, 
 particularly acids ; and, as the constants so obtained have 
 a very direct and intimate relation to those determined by 
 electrical conductivity and other methods of measurement 
 of chemical affinity, they are usually termed " affinity con- 
 stants." 
 
 Wilhelmy, in 1850, was the first to formulate a mathe- 
 matical expression of the laws governing the chemical 
 change produced by hydrolysis. Thereby was opened up 
 a field of research which has had enormous influence on 
 the science of chemistry as a whole, and greatly widened 
 
 1 Pentose sugars (C 5 H 10 O 5 ). 
 
252 THE POLARISCOPE IN SCIENTIFIC RESEARCH 
 
 our comprehension of the mechanism of chemical action. 
 His formulation is as follows : If B is the original amount 
 of sugar subjected to inversion at a fixed temperature under 
 the influence of an acid of known concentration A, and dx is 
 the amount inverted in a given increment of time dt ; x will 
 represent the sugar inverted at the end of t minutes, and 
 
 dx 
 
 = cA(B x\ where c is a constant dependent on the 
 
 nature of the acid and temperature. 
 
 By the mathematical method of integration, this becomes: 
 
 r> 
 
 nat log - = Act. 
 
 B x 
 
 B, the amount of cane sugar at the start (or at any chosen 
 moment during the reaction when t is taken as zero), is 
 directly proportional to R R 1 ', where R is the reading of 
 the polariscope given by the sugar solution at this chosen 
 moment, R f the reading of the solution when completely 
 inverted. The value of B x is proportional to R" R f , 
 R f [ being the polariscope reading taken at the time t. 
 Evidently Ac is a constant as calculated from this equa- 
 tion, since the concentration of the acid remains unchanged 
 throughout the inversion, owing to its action being catalytic. 
 
 If a series of the constants are obtained from inverting a 
 sugar solution by different acids, under fixed conditions of 
 temperature and concentration, their ratios will represent 
 the comparative affinities of the two acids. Usually these 
 are expressed in terms of the affinity value of hydrochloric 
 acid taken as 100. 
 
 The method of determining these afrinity constants does 
 not require detailed description. Outside of the usual 
 precautions necessary in precise polarimetric observations, 
 
THE POLARISCOPE IN SCIENTIFIC RESEARCH 253 
 
 the influence of even minute temperature variation must 
 be guarded against with particular care. The polariscope 
 tube or bath in which the inversion is taking place must 
 be carefully protected from radiation, and be kept at a 
 constant temperature by means of a circulating jacket or 
 other similar device in which the water temperature is kept 
 constant within the limits of measurement of a delicate 
 thermometer, certainly within .01 for accurate work. 
 Ingenious thermostats have been specially devised for this 
 accurate control. 
 
 Polarimetric readings are made at regular time intervals 
 reckoned in minutes from any chosen period in the course 
 of the inversion taken as an initial point. The reading of 
 the solution when so completely inverted that no further 
 change in the readings occurs must also be known. 
 
 As the value of the ordinary, or Briggs, logarithms bears 
 
 a constant relation f - j to those of the "natural" or 
 
 V-4343; 
 
 Naperian logarithms, the former are usually more conven- 
 ient to use, as the constant values so obtained can be 
 readily converted into the true constants as derived from 
 the exact formula. The calculation is very simple, as the 
 equation given above shows. The logarithm of the differ- 
 ence between the reading of the solution at the time t and 
 the reading of the completely inverted solution is subtracted 
 from the logarithm of the difference between the reading 
 at the initial moment when / is taken as zero and that of 
 the completely inverted solution. The value thus obtained 
 for each reading is divided by the appropriate number of 
 minutes which determine the time of the reading, the 
 quotient giving the required constant. 
 
254 THE POLARISCOPE IN SCIENTIFIC RESEARCH 
 
 The influence of temperature on hydrolytic change is 
 very great, the increase up to about 80 causing a very rapid 
 acceleration in the rate of inversion. Above this tempera- 
 ture, the temperature coefficient gradually diminishes, 
 the plot of the values forming a convex parabolic curve. 
 Unfortunately for the practical applications of the laws of 
 hydrolytic change, in spite of the enormous mass of data 
 which have been collected, these temperature coefficients 
 under different conditions of inversion have not been for- 
 mulated into any law of general application. 
 
 The work of Spohr, Urech, and Arrhenius has, however, 
 developed the following equation to express change in the 
 inversion constant of an acid at any temperature / be- 
 tween I and 50 : A^-TJ 
 C^CfC-sZT, 
 
 T being the temperature at which the inversion is made 
 and 7^ that at which the other inversion takes place, both 
 being expressed in absolute temperatures (/+ 273). e is 
 the natural logarithmic base, 2.718281. As this equation 
 requires the determination of a new constant, apparently 
 dependent on the special conditions of the inversion, it 
 can be applied only in specific cases where such constants 
 have been determined with more or less accuracy. 
 
 Sigmond found the value of A to be 12820 at 69.3 C, or 
 at about the most favorable inverting temperature of sucrose 
 He also found the equation held to 100 (Zeit. Phys. Chem., 
 27, 386). 
 
 Until these temperature laws on the constants of inver- 
 sion for the common acids are developed more completely, 
 the results of modern physical chemical research on hydro- 
 lytic change will have but a limited practical application 
 
THE POLARISCOPE IN SCIENTIFIC RESEARCH 2$ 5 
 
 for the sugar chemist, but they promise much in the future. 
 This sketch of the more important laws bearing on the 
 subject is introduced here merely to point out the great 
 value of polarimetric investigations in this line. 
 
 Hydrolysis of Starch. In the hydrolysis of starch prod- 
 ucts, the law expressing the rate of change is obviously 
 more complicated; for, if we consider the hydrolysis as 
 practically the resolution of the primary dextrin groups 
 into maltose and the simultaneous inversion of the latter 
 into dextrose, evidently the reaction has to deal with two 
 distinct chemical transformations taking place at the same 
 time. The transformation of dextrin into maltose is in 
 accord with the law discussed above, and consequently 
 can be expressed as in sucrose inversion by the equation : 
 
 (i) 
 
 A formula can be derived from the exact differential equa- 
 tion, 1 - = c^M, which states that the amount of dextrose 
 at 
 
 (Z>) formed at each moment is proportional to the amount 
 of maltose (M} present by replacing the differential quan- 
 tities by finite differences which in applications of the for- 
 mulae must be taken small. In the place of M, the average 
 amount of maltose present during the interval of time con- 
 sidered is substituted. That is, if M^ and M^ are the 
 amounts of maltose present at these times, and c 2 is the 
 reaction constant, the result of the above substitution is : 
 
 = '* ( 2 ) 
 
 /, - 
 
 1 Tech. Quart., 1897, T 55 (revised froih/. Am. Chem. Soc., 1896, 18). 
 
256 THE POLARISCOPE IN SCIENTIFIC RESEARCH 
 
 By these formulae two constants were found for each 
 conversion in a series of hydrolyses of corn starch made 
 with different acids under varying conditions of concentra- 
 tion of the hydrolyte and temperature. As the hydrolysis 
 of starch is relatively slow with dilute acids at ordinary 
 laboratory temperatures, the reactions were carried out 
 under steam pressure varying from i to 4 atmospheres in 
 
 FIG. 38. DIAGRAM OF AUTOCLAVE FOR ACID HYDROLYSIS OF STARCH 
 ARRANGED FOR REMOVAL OF SAMPLES WITHOUT INTERRUPTION. 
 
 an autoclave specially arranged for removal of portions of 
 the solution at any desired stage of the hydrolysis. The 
 amounts of dextrin and maltose per unit of total carbohy- 
 drate in solution were calculated from the specific rotatory 
 power of the solutions, by the method described in a pre- 
 vious chapter. The values so obtained were fairly constant, 
 tending to increase slowly as the hydrolysis proceeded. 
 
THE POLARISCOPE IN SCIENTIFIC RESEARCH 257 
 
 The comparative affinity constants of the acids used (hy- 
 drochloric, acetic, sulphuric, oxalic, and sulphurous) derived 
 from the results of this investigation, gave values in practi- 
 cal agreement with those obtained from sugar inversion. 1 
 
 Application of the Quartz-wedge Saccharimeter to General 
 Polarimetric Measurements. The great convenience in 
 manipulation and the precision of the quartz-wedge sac- 
 charimeter make it the most desirable instrument for 
 polarimetric measurements when its use is permissible. 
 The application of the quartz-wedge saccharimeter, how- 
 ever, is strictly limited by the following conditions : (i) the 
 restricted scale which measures rotations between about 
 35 and 10, although these measurements can be ex- 
 tended by the use of standard quartz plates of known 
 dextro- and levorotatory values ; (2) the necessary condition 
 that the " rotatory dispersion" of the solutions polarized 
 closely approximates to that of quartz ; that is, if the ratios 
 of the rotations of the different rays of the spectrum 
 caused by the solution are not practically identical with 
 those given by quartz, there will be no position of the 
 wedges at which the proper thickness of quartz can be 
 interposed to give complete compensation. Consequently, 
 in such cases, the end point given by the solution will not 
 be identical with that at the zero reading, and the precision 
 of the measurement will be seriously impaired thereby. 
 In the standard shadow saccharimeter, this unequal dis- 
 persion manifests itself by a party-colored field at the end 
 point instead of an equally tinted one. As the rays at the 
 violet end of the spectrum are the principal disturbing 
 
 1 For speed of hydrolysis of starch by diastase. See Brown and Glendin- 
 ning,/. Chan. Soc., 81, 388. 
 
258 THE POLARISCOPE IN SCIENTIFIC RESEARCH 
 
 ones, this party-colored field can be largely prevented by 
 filtering the light through a solution of potassium bichro- 
 mate, or a section of a crystal of this substance, when 
 the difference in dispersion is not great. In the case of 
 commercial glucose and most starch products, as well as 
 sugars other than sucrose, the bichromate cell is effectual, 
 md is usually part of the equipment of the saccharimeter. 
 If the inequality of dispersion is considerable, as in the 
 case of many essential oils, sodium light must be used. 
 
 Light Factor. The equivalent of one division of the 
 saccharimeter in angular degrees of rotation of the plane 
 of polarization of the standard yellow ray is called the 
 " light factor " of the saccharimeter. Until comparatively 
 recently, the factor .3455 was considered correct 1 in all 
 cases to convert readings in divisions of the Ventzke scale 
 to rotations of standard yellow light in angular degrees. 
 Landolt in 1888 and Rimbach in 1894 published results 
 of comparative readings of various sugars, showing that 
 this factor varied in many cases with the nature of the 
 sugar, being nearer to .345 for dextrose, for instance, than 
 .346; and establishing the fact that the light factor is 
 not a constant, but varies with the nature of the solution 
 polarized, being dependent on the difference between the 
 dispersion of the substance and that of quartz, as it is, 
 obviously, on temperature. There are also other variations 
 in light-factor values which have caused considerable con- 
 fusion in establishing the exact equivalent of the standard 
 quartz-wedge saccharimeter. These are due to the fact of 
 the existence of saccharimeters with scales based on a dif- 
 
 1 This factor is correct for the rotation equivalent as determined by quartz 
 readings on the Laurent polariscope at 17.5. 
 
THE POLARISCOPE IN SCIENTIFIC RESEARCH 259 
 
 ferent graduation from that of the Ventzke standard, and 
 furthermore to changes in the optical centre of the yel- 
 low light used as the standard of measurement in rotatory 
 polariscopes. The factor .3458 is correct at 20 for con- 
 version of the divisions of the standard Ventzke scale into 
 angular degrees of rotation as given on the Laurent sac- 
 charimeter, for substances having the same dispersive 
 power as quart z^ If, however, the light standard of the 
 Lippich ray filter is taken, the light factor becomes .3466, 
 while with the true centimeter saccharimeter scale, the 
 factor is more nearly .3469. In the case of cane sugar, the 
 factor is practically the same as quartz under the same 
 standards of measurement, but with hydrolyzed starch 
 products, with the Ventzke saccharimeter, it varies from 
 .3443 for the Laurent standard at 20 to about .3450 with 
 the Lippich ray. If sodium light is used with the saccha- 
 rimeter, the influence of dispersion will be eliminated, and 
 the factor will be constant at the same temperature for 
 all solutions. Use of sodium light sacrifices much of the 
 convenience of the quartz-wedge saccharimeter, but quali- 
 fies the instrument for measurements of all optically active 
 substances. 2 
 
 1 Throughout this book, it has been assumed on the authority of Landolt 
 (p. 364) that sodium light passed through the Lippich ray filter has an optical 
 centre practically identical with that of the spectrally purified light (see foot- 
 note, p. n). Recent rotation measurements of quartz plates do not, however, 
 confirm this identity in every case. 
 
 2 If the modern quartz-wedge saccharimeter is graduated to give the exact 
 sugar values for solutions at all concentrations represented on the scale, as 
 Von Lippmann ("Chem. der Zuckart.," Ill ed. 1363) asserts and many of the 
 quartz-plate readings made by the author show, obviously the light factor in 
 the middle of the scale will be slightly different from that at the ends. 
 For instance, the light factor of a U. S. standard instrument apparently so 
 graduated is .3467 at the 100 point, but .3469 at the 60. 
 
APPLICATION OF THE POLARISCOPE TO 
 CHEMICAL ANALYSIS OTHER THAN CAR- 
 BOHYDRATE DETERMINATIONS 
 
 WHILE there is a wide field for the application of the 
 polariscope in the analysis of many organic compounds, 
 comparatively few systematic methods of analysis have 
 been developed as yet. Perhaps one reason for this neg- 
 lect of the polariscope in quantitative organic analysis is 
 due to the fact that the specific rotations of most optically 
 active substances are affected to a large extent by the sol- 
 vents usually necessary in polarizing, as explained in the 
 preceding chapter. In consequence, since in the simple 
 equation expressing the fundamental laws of rotation, 
 
 a = - , a is not a constant at different concentrations, as 
 
 v 
 
 it is practically in the case of cane sugar, the formula for 
 calculation of the optically active substance is often very 
 complicated. This drawback is not a serious one, how- 
 ever, as is shown by the steadily increasing number of 
 polarimetric methods which are being applied in organic 
 analysis, and these will become of more general use as the 
 fundamental principles of optical analysis become better 
 known. As will be explained farther on, another reason 
 why little has been done in applying polarimetric methods 
 to the quantitative measurement of the optically active 
 substances themselves is the variation of these constituents 
 in most plant products, such as the essential oils and 
 
 260 
 
MISCELLANEOUS APPLICATIONS 26 1 
 
 drugs, as well as the complication of their mixture. 
 Hence the polariscope has been of service principally in 
 determining the purity of such products as are character- 
 ized by approximate rotation constants. These rotation 
 figures in conjunction with the density and refractive index 
 have been particularly valuable in the identification of the 
 essential oils and detection of adulterants. The indica- 
 tions of the instrument in such cases can be looked on as 
 in a sense qualitative rather than quantitative. 
 
 In general, the rotatory polariscope is more suitable for 
 determinations of oils and drugs, owing to the great varia- 
 tion in the rotation dispersion of these substances. The 
 quartz-wedge saccharimeter is, however, universally appli- 
 cable if sodium light is used as the illuminant and the 
 readings are converted into angular rotation equivalents 
 by the appropriate light factor. As many of the liquid 
 products can be put into the polariscope tube without 
 preparation and polarized directly, and as the specific ro- 
 tations are often very large, it may *be advisable to use 
 tubes of shorter lengths than for sugar analysis, even as 
 short as .25 decimeter. In exact quantitative measure- 
 ments with such tubes, due allowance must be made for 
 the increased error in the use of such short lengths. 
 
 Camphor. Forster 1 has devised a method for deter- 
 mining camphor in celluloid which is as follows : About 
 10 grams of celluloid are saponified with four times this 
 weight of sodium hydrate (10 per cent). After dilution 
 with water, the camphor is distilled off with steam and col- 
 lected in about 25 cubic centimeters of benzol by shaking 
 
 1 Ber. deut. chem. Ges., 23, 2981. See also for camphor in oils, Leonard 
 and Smith, Analyst, 25, 202. 
 
262 MISCELLANEOUS APPLICATIONS 
 
 up the distillate with that liquid. After making up to a 
 definite volume, the benzol solution is polarized at 20 C. 
 The specific rotation is expressed by the following 
 formula, [a]2o= 39.755 4- .1725 w, from which is derived 
 
 s \ 2 
 
 2^=2.4683 - .01747 f- j for the weight of camphor in 
 / \/ / 
 
 100 cubic centimeters. The equation is more complicated 
 than that expressing the concentration of sugar solutions, 
 owing to the marked action of the solvent on the rotation. 1 
 
 Chinchona Alkaloids. The valuable medicinal alkaloids 
 of the chinchona plants are very numerous, over thirty 
 having been isolated. They are all tertiary amines, 
 strongly basic in their nature, and most of them of pro- 
 nounced optical activity. Isomers and polymers are often 
 found together, so that an exact determination of the con- 
 stituent alkaloids in the bark of the plant by any polari- 
 metric method is too complicated to be practical. An 
 additional difficulty is the great influence that the ordinary 
 solvents of these alkaloids have on their specific rotations. 
 
 It is usually necessary to isolate the alkaloids by chemi- 
 cal separation processes before making a quantitative 
 determination by the polariscope. Many such processes 
 are in use. One will illustrate, the determination of 
 quinine and chinchonidine in a chinchona bark : 
 
 All the alkaloids present are first set free by treating 
 the powdered bark with calcium hydrate, by making a 
 paste with water ; then extracting with a mixture of three 
 parts of benzol and one of amyl alcohol, by boiling for 
 half an hour, and filtering off from the residue ; and finally 
 removed as the hydrochlorates, by treatment with dilute 
 
 1 Landolt, " Optische Drehungsvermogen," 169, also 453. 
 
MISCELLANEOUS APPLICATIONS 263 
 
 hydrochloric acid in a separatory funnel. The acid solu- 
 tion is carefully neutralized with ammonia, and the quinine 
 and chinchonidine precipitated as tartrates with Rochelle 
 salt. 
 
 The precipitation, which is facilitated by stirring, is com- 
 pleted in about an hour. Eighty per cent of the weight 
 of the washed and dried precipitate is composed of the 
 chinchonidine and quinine. A solution convenient for 
 polarizing can be obtained by dissolving the tartrates in 
 either dilute hydrochloric or sulphuric acid. As the rota- 
 tion of the two optically active substances in solution l is 
 the sum of their individual rotatory effects, equations can 
 be derived analogous to those already described in the 
 determination of the optically active constituents of hydro- 
 lyzed starch products. 
 
 If x is the per cent of quinine to be determined in a 
 known amount of the alkaloid salts and y the per cent of 
 chinchonidine, and [a]^ is the specific rotation of quinine 
 under the conditions of solvent and concentration used in 
 the analysis, [a] y being the corresponding specific rotation 
 of chinchonidine under like conditions : 
 
 then, x+y=. 100, 
 
 and [a]* x + [a] y -y = a 
 
 (a being the specific rotation of the alkaloid mixture). 2 
 By substituting 100 x for j, Hesse 3 develops the foi 
 
 1 Correction can be made for the tartaric acid set free in solution, if calcu- 
 lation shows that the error is large enough to affect the results ([a]/) = 1.950 
 + .13030?). 
 
 2 The percentage is expressed as a whole number, and not decimally as in 
 the equations for starch hydrolysis referred to. 
 
 3 Ann. Chem. (Liebig), 182, 146, also Oudemans, ibid., 182, 63. 
 
264 MISCELLANEOUS APPLICATIONS 
 
 lowing form for the equations expressing the per cents of 
 the alkaloids ; 
 
 y=ioo *. 
 M,- M, 
 
 Hesse, as cited by Landolt, 1 also gives a modified form of 
 these equations for the determination of the mixed alka- 
 loids in commercial quinine sulphate in which the rotation 
 values observed for a defined condition of tube-length, sol- 
 vent, and concentration are substituted for the specific rota- 
 tions. Two grams of the sample are dissolved in 10 cubic 
 centimeters normal hydrochloric acid and the solution 
 made with water to 25 cubic centimeters, / being 2.2 deci- 
 meters. The angular rotation of quinine under these con- 
 ditions is 40.309, and that of chinchonidine, 26.598. 
 Hence, for the conditions defined, if the corresponding 
 rotation of the sample is designated by Y> the per cent of 
 
 v + 26.598 
 quinine will be expressed by x = - - =^-, and the per 
 
 cent of chinchonidine by y = - : - - 
 
 - I37II 
 
 Evidently the first set of equations is generally appli- 
 cable, not only to alkaloids, but to any two optically active 
 substances in solution. 
 
 Hesse gives the following values for the specific rotation 
 of quinine hydrochlorate in water with varying quantities 
 of hydrochloric acid, the amount of acid being expressed 
 in " mols " (the molecular equivalent in grams in a liter), 
 
 1 " Optische Drehungsvermogen," 456. 
 
MISCELLANEOUS APPLICATIONS 265 
 
 the concentration ( J of the salt being 2 grams per 100 
 cubic centimeters : 
 
 mols HC1 o i 2 4 10 
 
 [a] ^5 -- 138.75 - 223.2 - 225.7 - 22 3-6 - 213.9 
 
 For a 2-mol solution of acid and a concentration of the 
 quinine salt, varying between I and 7 grams per 100 cubic 
 centimeters, the following equation expresses the specific 
 rotation at 15 C. : 
 
 [a]/)i5 = 229.46 + 2.21 w, 
 
 or, expressed in the weight of the alkaloid : 
 
 [a] ^ = 280.78 + 3-3 1 w- 
 
 The specific rotation of chinchonidine hydrochlorate in 
 water containing 2 mols of hydrochloric acid is for a con- 
 centration from i to 10: 
 
 [a]/>i5=- 154-07+ 1.39^- 
 
 A method for determining the other alkaloids of chin- 
 chona bark, in which polarimetric analysis is used, has 
 apparently not been worked out. The identification of 
 any of the alkaloids after separation, as well as determina- 
 tion of mixtures containing no more than two, is obviously 
 practicable in many cases. 
 
 Cocaine. The polariscope is said to be a valuable aid 
 in determining the purity of this alkaloid, which occa- 
 sionally is contaminated with dangerous natural impuri- 
 ties, notably cocamine. A polarimetric method of cocaine 
 determination has been developed by Antrick, 1 both for 
 
 1 Ber. deut. chem. Ges., 20, 320. 
 
266 MISCELLANEOUS APPLICATIONS 
 
 the extract and the hydrochlorate. The specific rotation 
 of cocaine in chloroform is given by the equation [a] 20 = 
 16.4124- .00585 /. In commercial analysis [a]/> is taken 
 as 16.32. From this is derived the simple equation for 
 the per cent of cocaine, /= 3.06 , where / is 2 deci- 
 meters. 
 
 Cocaine hydrochlorate has a specific rotation in 60 parts 
 of absolute alcohol in 90 parts of water, which is expressed 
 by the following equation : 
 
 [a]/>2o = 67.982 + . 1 583 w. 
 
 On account of the marked change in rotation with varying 
 amounts of solvent, the expression for the per cent is some- 
 what complicated. 
 
 The simplest expression, which is given by Antrick, is : 
 
 .7337^ + . 001454 a 2 
 d 
 
 Nicotine. The polarimetric method of Popovici l is 
 used in conjunction with Kissling's extraction process. 
 The alkaloid is first obtained in solution by treating about 
 30 grams of dry pulverized tobacco with 10 cubic centi- 
 meters of an alcoholic sodium hydrate solution, made by 
 dissolving 6 grams of sodium hydrate in 100 cubic centi- 
 meters of 57 per cent alcohol. The moistened mass is 
 extracted for three hours with ether in a Soxhlet appa- 
 ratus. The nicotine is precipitated in an impure state 
 from this ether extract by adding 10 cubic centimeters 
 of a strong nitric acid solution of phosphomolybdic acid 
 and shaking vigorously. The ether is decanted from the 
 
 1 Zeilsch. physioL Chem., 13, 445. 
 
MISCELLANEOUS APPLICATIONS 267 
 
 precipitate and water added to a volume of 50 cubic centi- 
 meters. The nicotine is finally set free in this alkaline 
 solution by adding 8 grams of dry pulverized barium 
 hydrate. After standing, with frequent shaking, the clear 
 liquor is decanted for polarizing. The simplest equation 
 
 a fa\? 
 
 derived by Landolt is, w .704- .000525! - j 
 
 Essential Oils. Most essential oils are optically active, 
 and offer an attractive field for polariscopic investigations. 
 As obtained from plants, these substances are not, how- 
 ever, homogeneous chemical compounds of strictly in- 
 variable composition, but differ considerably with the 
 conditions affecting the plant growth and the method of 
 extraction. As a rule, essential oils are complicated 
 combinations of a large number of compounds of very 
 varied nature. 
 
 Among the more important well-defined optically act- 
 ive bodies which have been isolated from essential oils are 
 the following terpenes of the general formula, C 10 H 16 , 
 most of which have been obtained as dextro- and levo- 
 isomers of equal rotating value : 
 
 Pinene, or terebcnthene, the dextro-isomer ([a]/) = 45.04) 
 being a characteristic ingredient of American oil of tur- 
 pentine. The levo-isomer ([a]/>= 44.95) is a compo- 
 nent of French oil of turpentine. 
 
 Camphene, which is also a component of turpentine, a 
 solid at ordinary temperatures, a levo-isomer being char- 
 acteristic of citronella oil as well as of French turpentine. 
 Camphene is also a component of many other oils, such as 
 rosemary and ginger. Its specific rotation, which seems to 
 be about 60, has not been definitely established. 
 
268 MISCELLANEOUS APPLICATIONS 
 
 Limonene, whose dextrorotatory isomer is an ingredient 
 of oils of orange peel, dill, bergamot, and many others of 
 less importance ; the levorotatory body, being found in 
 pine-needle oil, has a specific rotation of 105 at 10 (125.6 
 at 20). 
 
 Sylvestrene ([a]/>= i/.o 1 ), one or the other isomer found 
 in many turpentine oils. 
 
 Phellandrene(^ji\ D = 17.6), found in bitter fennel oil. Is 
 very unstable. 
 
 There are two important sesqui-turpenes (C 15 H 24 ) : 
 
 Cadinene, found in, a large number of essential oils, 
 [a]/), in chloroform, at 9.5C, for a 13 per cent solution, 
 = 98.56. 
 
 Caryophyllene, found in cloves and copaiba balsam, [a]/> 
 = - 8.96. 
 
 The following optically active paraffin alcohols have 
 been isolated. They usually are present in the oils as 
 esters of fatty acids. 
 
 Zz/ztf/<?0/(C 10 H 17 OH), the dextro-isomer in coriander oil, 
 the levo-isomer in many of the citrus oils, as lemon, berga- 
 mot, also in sage, thyme, lavender, spearmint, sassafras, 
 and others. The specific rotation has not been satisfacto- 
 rily determined, probably on account of impurities. It is 
 approximately 15. 
 
 CiVn>^//^/(C 10 H 19 OH), in dextro form in rose and gera- 
 nium oils, has not had its specific rotation definitely deter- 
 mined. It evidently lies between 2 and 4. 
 
 There are three important aromatic alcohols which have 
 been isolated from essential oils and found to be optically 
 active : 
 
 1 [ a l# i n chloroform solution, 66.32. 
 
MISCELLANEOUS APPLICATIONS 269 
 
 Terpeneol, a tertiary unsaturated alcohol (C 10 H 17 OH), 
 probably solid when pure, with a rotation, in alcoholic 
 solution, of about 85. It also exists in the inactive or 
 " racemic " modification, which is identical in its chemical 
 properties. The fact that the isomeric forms exist to- 
 gether in many oils makes the optical determination diffi- 
 cult. Terpeneol is found in cardamom, cajeput, lovage, 
 marjoram, and kuromoji oils among others. 
 
 Borneol (C^HtfOH) occurs in the free state naturally as 
 the solid Borneo camphor and in the levo-isomer as Ngai 
 camphor. It is also found as one or the other isomer in 
 many oils, as cardamom, spike, rosemary, citronella, vale- 
 rian, sage, and thyme. Like the other alcohols, borneol is 
 often present in the form of a fatty ester. In most sol- 
 vents, methyl alcohol being an exception, both isomers 
 give a practically constant specific rotation of 37.70. 
 
 Menthol, a saturated secondary alcohol only found in the 
 levo form as a constituent of peppermint oils. Long 1 
 gives the following rotation constants : 
 
 The melted solid at 46 : 
 
 </ 44 . 6 = .8810 [a] /) = -49-86; 
 
 alcoholic solution at 20 : 
 
 [a] z> = 48.247 .011108 q .00001870^; 
 benzene solution at 20 : 
 
 [>]/> = - 49-5 1 1 - -025634 q - .0008403 q* 
 (q being the per cent of solvent). 
 
 Of the aliphatic terpene aldehydes, only one optically 
 active one is important : 
 
 */. Am. Chem. Soc., 14, 149. 
 
2/O MISCELLANEOUS APPLICATIONS 
 
 Citronettat (CgHtfCllO), the dextro-isomer alone having 
 been isolated. It is a constituent of lemon, citronella, 
 eucalyptus, and balm oils ([a]/>7.5= 12.50). 
 
 Of the large number of aromatic aldehydes which make 
 up the odoriferous constituents of so many ethereal oils, no 
 important optically active ones have been isolated. The 
 following ketones are optically active : 
 
 Carvone (C 9 H 16 CO), which is found as the dextro-isomer 
 ([0,]^= 62.65) in dill and caraway oils, and in the levo 
 form in spearmint and kuromoji ([a]^ = 62.41). 
 
 Camphor (C 9 H 16 CO), besides coming from its principal 
 commercial source, the secretion of the camphor tree, is a 
 constituent of many plants, such as sassafras, cinnamon 
 root, spike, and rosemary. The levo-isomer has been 
 found in feverfew and tansy. The specific rotation of 
 camphor has been calculated by Landolt to be 55.4. Lan- 
 dolt has also determined the equations for the specific 
 rotation of camphor in the following solvents : benzol, 
 ethyl alcohol, dimethyl aniline, acetic acid, methyl alcohol, 
 monochloracetic ether, and acetic ether. Benzol is usu- 
 ally the most convenient solvent for polarizing, the rotation 
 formula for this solvent being already given (page 262). 
 The temperature should be kept practically constant at 
 20, as changes have marked influence on the rotation. 
 
 Fenchone (C 9 H 16 CO) much resembles camphor. It t 
 found in fennel as the dextro-isomer, and in thuja in the 
 levo form. The specific rotation of the dextro-isomer has 
 been found to be, in a 10 per cent alcohol solution, 71.8, 
 the levo-isomer giving 66.9. 
 
 Thujone (C 9 H 16 CO), found in the dextro form in worm- 
 wood, tansy, and sage. The specific rotation is 21.1. 
 
MISCELLANEOUS APPLICATIONS 2/1 
 
 Pulegone (C 9 H 16 CO) is found in pennyroyal in dextro 
 form ([a]/>2o = 22.89). 
 
 Menthone (C 9 H 18 CO) occurs in peppermint and gera- 
 nium oils and in buchu leaves. Like the corresponding 
 alcohol, menthol, it is only found in the levo form 
 ([>]/*. = - 28.18, [a] ^4 = - 27.67). 
 
 This list of some of the more important optically active 
 constituents of the volatile oils is far from complete, but it 
 serves to indicate the variety and complexity of the combi- 
 nations which make up these interesting products, and the 
 immense field for research which is presented to the polari- 
 scopist. Rigidly formulated methods of procedure cannot 
 be given for the investigation of even the common essential 
 oils, but the analyst must combine an acquaintance with 
 the local conditions of their production with an intimate 
 knowledge of the chemical composition of the oil and its 
 probable adulterants. 
 
 The case of oil of lemon will illustrate this point. The 
 bulk of this oil comes from southern Italy and Sicily. 
 The oil from Messina has a specific rotation at 20 C. of 
 59, or from some years' crops even less. The oil from 
 Syracuse has a rotation sometimes as high as 67. Other 
 districts produce oils with rotation values lying between 
 these extremes, the average being about 60. Turpentine 
 is often an adulterant. If the turpentine is American, its 
 specific rotation is usually about 6 ; if French, 30. Sub- 
 stituting the average rotation value of 60 for the lemon oil 
 and the value for turpentine, when chemical and physical 
 tests have shown which kind is present, in the general equa- 
 tion discussed under chinchona alkaloids, the proportion 
 of the adulterant can be determined. If, however, the 
 
2/2 MISCELLANEOUS APPLICATIONS 
 
 strongly rotating oil of orange ([a] ^ = 98) has been added 
 to disguise the turpentine, a further separation must be 
 made by steam distillation, when the lower boiling turpen- 
 tine will in the main distill off in the first fraction and so be 
 detected by the polariscope by the low rotation. As tem- 
 perature affects the rotations considerably, polarizations 
 must be made at 20. 
 
 If the oil is known to be pure, the polariscope can be 
 used to determine the strength of an alcoholic solution, 1 such 
 as a lemon flavoring extract for instance, by a simple appli- 
 cation of the principles of polarimetric analysis already 
 familiar. Such a method is in practice. 
 
 For a full exposition of the chemistry and analysis of 
 ethereal oils, see Gildermeister and Hoffmann's work on the 
 volatile oils, translated by Kremers. The data of the 
 optical constants, as far as they are known, of some 
 four hundred oils are given in this work. See also the 
 data given by Schimmel & Co. in Landolt's " Optische 
 Drehungsvermogen," page 578. 
 
 Heavy Oils. The polariscope has comparatively little 
 application in the chemistry of the heavy oils. Rosin oil, 
 a product of destructive distillation of turpentine residuums 
 (rosins) is often used as an adulterant of the fatty oils on 
 account of its cheapness. The optical activity of this oil 
 
 1 Many cheap lernon extracts are made from " washed " or " terpeneless " 
 oil, being solutions of practically pure citral made from oil of lemon or oil of 
 citronella (lemon-grass) by distilling off the low-boiling and optically active 
 terpenes. Citral is soluble in dilute alcohol, so that the expense of manu- 
 facture is greatly economized. Other terpeneless essential oils are also made, 
 and many oils are improved by this process, as the terpenes are usually not 
 the characteristic odoriferous principles, and the solubility of the oil is increased. 
 The distilled terpenes are used as adulterants of pure oils. 
 
MISCELLANEOUS APPLICATIONS 273 
 
 serves for its detection. The greatest difficulty in polari- 
 metric determinations of the heavy oils is in clarifying, as 
 the usual methods cause decomposition of the product, and 
 it is often impossible to isolate the oil by distillation. Often 
 the only practicable way is to dilute with some solvent, 
 which of course greatly diminishes the precision of the 
 measurements, especially as the rotations are as a rule 
 small. 
 
 Gill and Mason l have used the polariscope as an aid to 
 the detection of mineral oil in the distilled grease oleines 
 recovered from wool scouring. These " oleines " as wool 
 oils are of importance in the woolen industries, where they 
 are used for oiling wool preparatory to spinning. As the 
 specific rotation of the unmixed grease lies between 16 and 
 1 8, the addition of the optically inactive 2 adulterant is 
 readily shown. The oil was diluted with ten parts of benzol 
 for polarizing. 
 
 Gallotannic Acid. Wood-Smith and Regis have worked 
 up a method for determining gallotannic acid in tanning 
 materials, which is based on the change of rotation in a gela- 
 tin solution, which has been clarified with white of egg, 
 by its combination with gallotannic acid. As the method 
 is quite empirical in its details, the reader is referred to the 
 original paper (Analyst, 23, 33). 
 
 Tartaric Acid and Tartrates. E. B. and F. B. Kenrick 3 
 have developed methods for the determination of tartaric 
 acid and tartrates, particularly devised for baking powders 
 and effervescent mixtures. The authors have made an 
 
 l /. Am. Chem. Soc., 26, 665. 
 
 2 Gill and Mason found a very slight optical activity in some petroleum oils. 
 8 /. Am. Chem. Soc., 24, 928. 
 T 
 
2/4 MISCELLANEOUS APPLICATIONS 
 
 extensive investigation of the influence of many common 
 salts and acids on solutions containing tartaric acid in 
 which sugar or starch is present or absent. Experiment 
 showed that when soluble tartrates or calcium tartrate 
 were alone present, and substances disturbing the rota- 
 tion, like iron or alumina, were absent, the rotation of the 
 jartrate in an excess of ammonia was proportional to the 
 concentration and could be expressed as tartaric acid by 
 the following equation, w = .00519^; x being the angular 
 rotation for the sodium light in minutes when the concen- 
 tration of the tartrate was about 2 grams in 50 cubic centi- 
 meters of ammonia solution containing an excess no more 
 than equivalent to 2 cubic centimeters of the concentrated 
 ammonia. If the mixture contains the insoluble calcium 
 tartrate, the mixture must be dissolved in a dilute solution of 
 hydrochloric acid (20 drops in 30 cubic centimeters of water). 
 The solution is effected by heating gently. Four cubic centi- 
 meters of ammonia are added to the solution and about .2 
 gram of sodium phosphate ; the mixture is cooled, made up 
 to 50 cubic centimeters, and filtered. The sodium phosphate 
 precipitates the lime, and is not absolutely necessary unless 
 the proportion of calcium is large, when it prevents the lat- 
 ter from crystallizing out of the solution. A 2-decimeter 
 tube is used. 
 
 If sugar is present in the mixture, it must be determined 
 by the Clerget method, and its rotation allowed for. If 
 magnesium be present, as it is in many effervescent mix- 
 tures, it must first be precipitated by sodium phosphate 
 and ammonia, as it influences the rotation values of both 
 the tartaric acid and the sugar. Further, it is necessary to 
 add the appropriate amount of acid for inverting, inde- 
 
MISCELLANEOUS APPLICATIONS 2^ 
 
 pendently of the amount which goes into combination with 
 the bases present to free any organic acids present. In 
 this case an amount of substance, corresponding to about 
 8 grams of substance or 5 grams of sugar, is made up to 
 100 cubic centimeters ; 25 cubic centimeters of this solution 
 is put into a 5O-cubic-centimeter flask, and if alkaline neu- 
 tralized with hydrochloric acid, using methyl orange as an 
 indicator ; i cubic centimeter of ammonia is added, and the 
 solution made up to mark and polarized. 
 
 The amount of hydrochloric acid necessary to set free 
 any combined organic acids, and, consequently, not avail- 
 able as an inverting agent, is determined by adding the 
 acid to a second portion of 25 cubic centimeters of the 
 original solution, to which methyl violet has been added 
 till the solution just turns green, showing an excess of the 
 free mineral acid. A third 25 cubic centimeters of the 
 solution, placed in a 5o-cubic-centimeter flask, is now 
 inverted by adding just the amount of acid necessary to 
 set free the organic acids, in addition to that necessary to 
 invert, which is 2.5 cubic centimeters. The Clerget pro- 
 cess is carried out in the usual way, and, after cooling, the 
 acid is neutralized with ammonia, i cubic centimeter excess 
 added, and the solution polarized after making up to the 
 50 mark. The calculation formula given by the authors 
 
 2(a 6)1.254 
 is, for sugar, z = , a and b being expressed 
 
 in minutes. The rotation of the tartaric acid is x2a 
 79.7 #, and the weight of acid, w = 4(.oos 19^). 
 
 If magnesium is present, only 10 cubic centimeters of the 
 original solution, made up as described, containing about 
 8 grams of tartrate in 100 cubic centimeters, is used, and 
 
276 MISCELLANEOUS APPLICATIONS 
 
 the magnesium precipitated by using as nearly as possible 
 the exact amount of reagent necessary; the precipitate 
 being removed by means of a filter pump so that the wash 
 waters, which are to be polarized and inverted, are reduced 
 to as small a bulk as possible, not to exceed 100 cubic 
 centimeters, to which the solution is made up in this case. 
 Twenty-five cubic centimeters are tested to determine the 
 amount of inverting acid necessary, as already described, 
 and 25 cubic centimeters prepared and inverted in the 
 manner also described, and made up to 50 cubic centi- 
 meters. The equations in this case become : 
 
 _ io(a 2^)1.254 
 142 --5' ' 
 79.7 z y 
 
 If iron or alumina salts are present, the polarizations must 
 be made in neutral ammonium molybdate solution; the 
 solution must be strictly neutral and phosphates must 
 be removed. As the molybdic acid greatly increases the 
 rotation of the tartrate, an amount of sample containing 
 only .2 gram of tartrate is taken in a dry flask, with 
 10 cubic centimeters citric acid (c^-^) and 10 cubic centi- 
 meters ammonium molybdate (c -Q), and allowed to react 
 for five minutes, the flask being shaken occasionally. 
 Then 5 cubic centimeters of magnesium sulphate solution 
 (c= g6_o^ an d IO cubic centimeters ammonia (165 cubic 
 centimeters ammonia, ^=.924, in 500 cubic centimeters). 
 These solutions are exactly measured, making the volume 
 35 cubic centimeters. If the substance tested is a liquid, 
 allowance for its volume is made by taking less ammonia 
 
MISCELLANEOUS APPLICATIONS 277 
 
 solution. Within an hour the solution is filtered and 20 
 cubic centimeters measured into a 5o-cubic-centimeter flask, 
 and dilute hydrochloric acid added to faint acidity as shown 
 by methyl orange. Ten cubic centimeters of the molybdate 
 solution are then added, and the whole made up with water 
 to 50 cubic centimeters. The solution is now polarized 
 after filtering, if necessary, in a 2-decimeter tube. The 
 specific rotations of tartrates in neutral molybdate solutions 
 were found by the authors to be practically constant at 
 different concentrations. The equation for determining 
 the tartaric acid under these circumstances is w. 00121 x, 
 x being, as in all the equations given, the angular rotation 
 of sodium light expressed in minutes. 
 
 The author has had no experience with many of these 
 methods, but mentions them as illustrations of how such 
 determinations are worked out. In the present state of 
 our knowledge of the optical constants of many com- 
 pounds which can be determined by polarimetric analysis, 
 it will be necessary for the analyst to devise his own 
 method for the case at hand. This should not be difficult 
 with a proper comprehension of the principles set forth. 
 In fact, the aim in writing this little book has been in the 
 main to show how these principles have been successfully 
 applied, and to assist the reader in acquiring knowledge 
 which will enable him to attack effectively any problem of 
 the kind which comes to hand. It is confidently believed 
 that such knowledge will greatly extend the use of the 
 polariscope in the chemical laboratory. If this book does 
 its part in aiding this extension, it has not failed of its 
 purpose. 
 
APPENDIX 
 
 BIBLIOGRAPHY OF THE MORE IMPORTANT WORKS OF 
 REFERENCE 
 
 General Chemistry of Carbohydrates. 
 
 Tollens. Handbuch der Kohlenhydrate. Vol.1. 1888. Vol.11 
 (supplementary). 1895. (Contains bibliography of original 
 papers.) 
 
 Maquenne. Les Sucres et principaux De'rive's. 1900. 
 
 Von Lippmann. Chemie der Zuckerarten. 1904. (3d Ed.) 
 (Bibliography.) 
 
 Technology of Sucrose. 
 
 Wiley. Bulletins of Division of Chemistry, United States Depart- 
 ment of Agriculture. 
 
 (Cane Sugar and Sorghum), 2, 3, 5, 6, 8, 14, 17. 
 
 (Sorghum), 20, 26, 29, 34, 37, 40. 
 
 (Beet Sugar), 27, 30, 33, 36, 39, 72, 52 (revised), 64, 78 
 
 Also Special Reports, 1897, 1898, 1899. 
 (Sugar Producing Plants), 18. 
 Spencer. (Cane Sugar), ibid, n, 15, 21. 
 Crampton. (Cane Sugar), ibid. 22. 
 Edson. (Cane Sugar), ibid. 23. 
 
 Basset. Guide pratique du Fabricant de Sucre. 1882. 
 Horsin-Don. Fabrication de Sucre. 1882. 
 Lock and Newlands Bros. Handbook for Planters and Sugar 
 
 Manufacturers. 1888. 
 
 Von Lippmann. Geschichte des Zuckers. 1890. 
 Roth. Literature of Sugar. 1890 (bibliography). 
 Watts. An Introductory Manual for Sugar Growers. 1893. 
 
 279 
 
280 APPENDIX 
 
 Beaudet-Pellet-Saillard. Traite" de la Fabrication du Sucre. 1894. 
 Stubbs. Sugar Cane (Vol. I). The Chemistry and Manufacture of 
 
 Sugar (Vol. II). 1897. 
 
 Horsin-Don. Le Sucre et PIndustrie sucriere. 1894. 
 Stohmann. Zuckerfabrikation. (4th Ed.) 1899. 
 Sadtler. Handbook of Industrial Organic Chemistry. (3d Ed.) 
 
 1900. 
 
 Deerr. Sugar House Notes and Tables. 1900. 
 Bass. Cane Sugar (English and Spanish text). 1901. (2dEd.) 
 Geschwind et Sellier. La Betterave. 1902. 
 Quivy. L'Epuration des Jus Sucre's par Electricite. 1902. 
 Mittelstaedt. Aus der Praxis der Zuckerindustrie. 1902. 
 Prinsen-Geerligs. On Cane Sugar. 1903. (2d Ed.) 
 Teyssier. Fabrication du Sucre. 1904. 
 Stillman. Cane Sugar Machinery (English and Spanish text). 
 
 1904. 
 
 Mackintosh. Technology of Sugar. 1904. 
 Claassen. Die Zuckerfabrikation. 1904. 
 Colsen. Culture Industrie de la Canne a Sucre aux Isles Hawai, 
 
 (2d Ed.) 1905. 
 Thorp. Outlines of Industrial Chemistry. (2d Ed.) 1905. 
 
 Periodicals of Sugar Technology. 
 
 Zeitschrift des Vereins der deutschen Zuckerindustrie. 
 
 Neue Zeitschrift fur Rubenzuckerindustrie. 
 
 Stammer. Jahrsbericht der Zuckerfabrikation. 
 
 Bulletin de PAssociation des Chimistes de Sucrerie et de Distillation 
 
 The Louisiana Sugar Planter and Sugar Manufacturer. 
 
 The Hawaiian Planter's Monthly. 
 
 The Sugar Cane. (British.) 
 
 Die Deutsche Zuckerindustrie. 
 
 Centralblatt flir die Zuckerindustrie. 
 
 Osterreichisch-Ungarische Zeitschrift fur Zuckerindustrie (etc.). 
 
APPENDIX 28l 
 
 La Sucrerie Beige. 
 
 Zeitschrift fur Zuckerindustrie in Bohmen. 
 
 Analytical Methods and Chemical Control of Sugar (sucrose] 
 Manufacture. 
 
 Spencer. Handbook for Sugar Manufacturers. (Cane Sugar.) 
 1889. 
 
 Tucker. Manual of Sugar Analysis. 1890. 
 
 Wiechmann. Sugar Analysis. 1890. 
 
 Sidersky. Traite* d'Analyse der Materieres sucre*es. 1890. 
 
 Steydn. Die Untersuchungen der Zuckers und Zuckerhaltigen 
 Stone. 1893. 
 
 Wiley. Principles and Practice of Agricultural Chemical Analysis. 
 1896. 
 
 Peffer. Beet Sugar Analysis. 1897. 
 
 Spencer. Handbook for Beet-sugar Manufacturers. 1897. 
 
 Sidersky. Aide-Mmoire de Sucre* rie. 1898. 
 
 Broquet and Dethier. Manuel d'Analyse Chimique 1'Usage des 
 Fabricants de Sucre. 1898. 
 
 United States Treasury. Bulletin 2113. Revised Regulations 
 governing the Sampling and Classification of Imported 
 Sugars and Molasses. 1899. 
 
 Fruhling. Anleitung zur Untersuchung der fur die Zuckerindus- 
 trie in Betracht kommenden. Rohmaterialien, Produkte, 
 Neben Produkten und Hilfssubstanzen. (6th Ed.) 1903. 
 
 Stolle. Handbuch fur zuckerfabriks Chemiker. 1904. 
 
 Morse. Calculations used in Cane-sugar Factories. 1904. 
 
 Lactose. Analytic Methods. 
 
 Wiley. Principles and Practice of Agricultural Chemical Analysis. 
 
 Vol. III. 1896. 
 United States Department of Agriculture Division of Chemistry. 
 
 Bulletin 46. (Revised.) 
 
282 APPENDIX 
 
 Starch and Starch Products Analytic and Technical. 
 
 Wagner. Starkefabrikation. 1886. 
 
 Birnbaum. Starkezucker. 1886. 
 
 National Academy of Sciences. Report on Glucose. 1884 
 
 Fritsch. La Fecule. 1890. 
 
 Griffiths. Principal Starches used as Food. (Photomicrographs., 
 
 1892. 
 
 Saare. Fabrikation de Kartoffelstarke. 1897. 
 Sadtler. Handbook of Industrial Organic Chemistry. 1900. 
 Heron. Thorpe's Dictionary of Applied Chemistry. (Articles, 
 
 " Sugar " and " Starch.") 1900. 
 O'Sullivan and Heron. Ibid. Articles, "Dextrin," "Dextrose," 
 
 and " Maltose." 
 Bersch. Die Fabrikation von Starkezucker, Dextrin, Zuckercoleur 
 
 und Invertzucker. 1901. 
 
 Thorp. Outlines of Industrial Chemistry. (2d Ed.) 1905. 
 Wiley. (Cassava and Potato Starch.) Bulletin of Division of 
 
 Chemistry, United States Department of Agriculture, 44 and 58. 
 
 Sugar Analysis applied to Brewing. 
 
 Moritz and Morris. Text-book of the Science of Brewing. 1890. 
 
 Prior. Maltz und Bier. 1896. 
 
 Brown (Adrian). Laboratory Studies for Brewing Students. 1904. 
 
 Polarimetric Methods in Food Analysis. 
 
 Leach. Food Inspection and Analysis. 1904. 
 United States Department of Agriculture Division of Chemistn 
 Bulletins 46 (revised), 65, and 66. 1902. 
 
 Polarimetric Methods applied to Essential Oils and Drugs. 
 
 Allen. Commercial Organic Analysis. Vol. Ill, Part 2. 1892. 
 Parry. The Chemistry of the Essential Oils and Artificial Per- 
 fumes. 1899. 
 
APPENDIX 283 
 
 Gildermeister and Hoffmann. (Translated by Kremers.) The 
 Volatile Oils. 1902. 
 
 Optics of the Polariscope and General Theoretical Principles. 
 
 Tyndall. Notes on Light. 1882. 
 
 Landolt. Das optische Drehungsvermogen. 1898. 
 
 Preston. Theory of Light. (3d Ed.) 1901. 
 
 Landolt. (Translated by Long.) Optical Rotation of Organic 
 
 Substances. 1902. 
 Heron. Thorpe's Dictionary of Applied Chemistry. (Article, 
 
 " Sugar " ; section, " Saccharimetry.") (Excellent exposition 
 
 of whole subject.) 
 
TABLES 
 
 . HYDROiMETER TABLE FOR AQUEOUS SUGAR SOLUTIONS 
 AT I7.5C. 
 
 (Specific gravity referred to water at 17.5) 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 17.5\ 
 GRAVITY V 17.5/ 
 
 DEGREES 
 BAUME 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 17.5\ 
 GRAVITY \ a 17.5/ 
 
 DEGREES 
 BAUME 
 
 o.o 
 
 1. 00000 
 
 0.00 
 
 4.0 
 
 1.01570 
 
 2 27 
 
 O.I 
 
 1.00038 
 
 0.06 
 
 4.1 
 
 .01610 
 
 2-33 
 
 O.2 
 
 1.00077 
 
 O.I I 
 
 4.2 
 
 .01650 
 
 238 
 
 o-3 
 
 1.00116 
 
 0.17 
 
 4-3 
 
 .01690 
 
 2-44 
 
 0.4 
 
 1.00155 
 
 0.23 
 
 4.4 
 
 .01730 
 
 2.50 
 
 -5 
 
 1.00193 
 
 0.28 
 
 4-5 
 
 .01770 
 
 2-55 
 
 0.6 
 
 1.00232 
 
 0-34 
 
 4.6 
 
 .01810 
 
 2.61 
 
 0.7 
 
 1.00271 
 
 0.40 
 
 4-7 
 
 .01850 
 
 2.67 
 
 0.8 
 
 1.00310 
 
 0-45 
 
 4.8 
 
 .01890 
 
 2.72 
 
 0.9 
 
 1.00349 
 
 0.51 
 
 4.9 
 
 .01930 
 
 2.78 
 
 I.O 
 
 1.00388 
 
 0-57 
 
 5-0 
 
 .01970 
 
 2.84 
 
 I.I 
 
 1.00427 
 
 0.63 
 
 5-1 
 
 .02010 
 
 2.89 
 
 .2 
 
 1 .00466 
 
 0.68 
 
 5-2 
 
 .02051 
 
 2.95 
 
 3 
 
 1.00505 
 
 0.74 
 
 5-3 
 
 .02091 
 
 3.01 
 
 4 
 
 1.00544 
 
 0.80 
 
 5-4 
 
 .02131 
 
 3.06 
 
 5 
 
 1.00583 
 
 0.85 
 
 5-5 
 
 .02171 
 
 3.12 
 
 .6 
 
 1.00622 
 
 0.91 
 
 5-6 
 
 .O22I I 
 
 3.18 
 
 7 
 
 1.00662 
 
 0.97 
 
 5-7 
 
 1.02252 
 
 3.23 
 
 .8 
 
 1.00701 
 
 1.02 
 
 5-8 
 
 I .O2292 
 
 3.29 
 
 9 
 
 1.00740 
 
 1. 08 
 
 5-9 
 
 L02333 
 
 3-35 
 
 2.0 
 
 1.00779 
 
 I.I4 
 
 6.0 
 
 1.02373. 
 
 3-40 
 
 2.1 
 
 1.00818 
 
 I.I9 
 
 6.1 
 
 I.024I3 
 
 3-4 6 
 
 2.2 
 
 1.00858 
 
 1.25 
 
 6.2 
 
 1.02454 
 
 3-52 
 
 2 -3 
 
 1.00897 
 
 I-3 1 
 
 6-3 
 
 1.02494 
 
 3-57 
 
 2. 4 
 
 1.00936 
 
 1-36 
 
 6.4 
 
 L02535 
 
 3.63 
 
 2.5 
 
 1.00976 
 
 1.42 
 
 6-5 
 
 1.02575 
 
 3-69 
 
 2.6 
 
 1.01015 
 
 1.48 
 
 6.6 
 
 I.026l6 
 
 3-74 
 
 2.7 
 
 1.01055 
 
 i-53 
 
 6.7 
 
 1 .02657 
 
 3-80 
 
 2.8 
 
 1.01094 
 
 i-59 
 
 6.8 
 
 1.02697 
 
 3.86 
 
 2. 9 
 
 1.01134 
 
 1.65 
 
 6.9 
 
 1.02738 
 
 3-91 
 
 3-0 
 
 1.01173 
 
 1.70 
 
 7.0 
 
 1.02779 
 
 3-97 
 
 3.1 
 
 1.01213 
 
 1.76 
 
 7-1 
 
 I.028I9 
 
 4.03 
 
 3-2 
 
 1.01252 
 
 1.82 
 
 7.2 
 
 1.02860 
 
 4.08 
 
 3-3 
 
 1.01292 
 
 1.87 
 
 7-3 
 
 I.0290I 
 
 4.14 
 
 3-4 
 
 1.01332 
 
 i-93 
 
 7-4 
 
 1.02942 
 
 4.20 
 
 3-5 
 
 1.01371 
 
 1.99 
 
 7-5 
 
 1.02983 
 
 4.25 
 
 3-6 
 
 1.01411 
 
 2.04 
 
 7.6 
 
 1 .03024 
 
 4-31 
 
 3-7 
 
 1.01451 
 
 2.10 
 
 7-7 
 
 1.03064 
 
 4-37 
 
 3-8 
 
 1.01491 
 
 2.l6 
 
 7.8 
 
 I.03I05 
 
 4-42 
 
 3-9 
 
 1.01531 
 
 2.21 
 
 7-9 
 
 1.03146 
 
 4.48 
 
 285 
 
286 
 
 TABLES 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 17.5\ 
 GRAVITY \ 17.57 
 
 DEGREES 
 
 BAUMfe 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 17.5\ 
 GRAVITY \ a 17.5/ 
 
 DEGREES 
 BAUME 
 
 8.0 
 
 1.03187 
 
 4-53 
 
 13.0 
 
 1.05276 
 
 7.36 
 
 8.1 
 
 1.03228 
 
 4-59 
 
 I3.I 
 
 1.05318 
 
 7.41 
 
 8.2 
 
 1 .03270 
 
 4.65 
 
 13.2 
 
 1.05361 
 
 7-47 
 
 8-3 
 
 1.03311 
 
 4.70 
 
 13-3 
 
 1.05404 
 
 7-53 
 
 8.4 
 
 1.03352 
 
 4.76 
 
 13-4 
 
 1.05446 
 
 7.58 
 
 8-5 
 
 1-03393 
 
 4.82 
 
 13-5 
 
 1.05489 
 
 7.64 
 
 8.6 
 
 1.03434 
 
 4.87 
 
 13-6 
 
 L05532 
 
 7-69 
 
 8-7 
 
 1-03475 
 
 4-93 
 
 13-7 
 
 1-05574 
 
 7-75 
 
 8.8 
 
 I-035I7 
 
 4.99 
 
 13-8 
 
 1.05617 
 
 7.81 
 
 8.9 
 
 I-03558 
 
 5.04 
 
 13-9 
 
 1.05660 
 
 7.86 
 
 9.0 
 
 1 -03599 
 
 5.10 
 
 14.0 
 
 1.05703 
 
 7.92 
 
 9-1 
 
 1 .03640 
 
 5.16 
 
 14.1 
 
 1.05746 
 
 7.98 
 
 9.2 
 
 1.03682 
 
 5-21 
 
 14.2 
 
 1.05789 
 
 8.03 
 
 9-3 
 
 1.03723 
 
 5-27 
 
 14-3 
 
 1.05831 
 
 8.09 
 
 9.4 
 
 1.03765 
 
 5.33 
 
 14.4 
 
 1.05874 
 
 8.14 
 
 9-5 
 
 1.03806 
 
 5.38 
 
 14-5 
 
 1.05917 
 
 8.20 
 
 9.6 
 
 1.03848 
 
 5-44 
 
 14.6 
 
 1.05960 
 
 8.26 
 
 9-7 
 
 1.03889 
 
 5.50 
 
 14.7 
 
 1.06003 
 
 8.31 
 
 9.8 
 
 1.03931 
 
 5-55 
 
 14.8 
 
 1.06047 
 
 8.37 
 
 9-9 
 
 1.03972 
 
 5.6i 
 
 14.9 
 
 1.06090 
 
 8.43 
 
 IO.O 
 
 1.04014 
 
 5.67 
 
 15-0 
 
 1.06133 
 
 8.48 
 
 10. 1 
 
 1.04055 
 
 5-72 
 
 I5-I 
 
 1.06176 
 
 8.54 
 
 10.2 
 
 1.04097 
 
 5.78 
 
 15-2 
 
 1.06219 
 
 8.59 
 
 10.3 
 
 1.04139 
 
 5.83 
 
 J 5.3 
 
 1.06262 
 
 8.65 
 
 10.4 
 
 1.04180 
 
 5.89 
 
 15-4 
 
 i .06306 
 
 8.71 
 
 10.5 
 
 1.04222 
 
 5-95 
 
 15.5 
 
 1.06349 
 
 8.76 
 
 10.6 
 
 1.04264 
 
 6.00 
 
 15.6 
 
 1.06392 
 
 8.82 
 
 10.7 
 
 1.04306 
 
 6.06 
 
 15-7 
 
 1.06436 
 
 8.88 
 
 10.8 
 
 1.04348 
 
 6.12 
 
 15.8 
 
 1.06479 
 
 8.93 
 
 10.9 
 
 1.04390 
 
 6.17 
 
 15-9 
 
 1.06522 
 
 8.99 
 
 II .0 
 
 1,04431 
 
 6.23 
 
 16.0 
 
 1.06566 
 
 9-04 
 
 n. i 
 
 1.04473 
 
 6.29 
 
 16.1 
 
 1.06609 
 
 9.10 
 
 II. 2 
 
 1-04515 
 
 6.34 
 
 16.2 
 
 1.06653 
 
 9.16 
 
 "3 
 
 1-04557 
 
 6.40 
 
 16.3 
 
 1.06696 
 
 9.21 
 
 11.4 
 
 1.04599 
 
 6.46 
 
 16.4 
 
 1.06740 
 
 9.27 
 
 ii-5 
 
 1.04641 
 
 6.51 
 
 16.5 
 
 1.06783 
 
 9-33 
 
 II.6 
 
 1.04683 
 
 6.57 
 
 16.6 
 
 1.06827 
 
 9.38 
 
 11.7 
 
 1.04726 
 
 6.62 
 
 16.7 
 
 1.06871 
 
 9-44 
 
 n.8 
 
 1.04768 
 
 6.68 
 
 16.8 
 
 1.06914 
 
 9.49 
 
 11.9 
 
 1.04810 
 
 6.74 
 
 16.9 
 
 1.06958 
 
 9-55 
 
 12.0 
 
 1.04852 
 
 6.79 
 
 17.0 
 
 1.07002 
 
 9.61 
 
 12. 1 
 
 1.04894 
 
 6.85 
 
 17.1 
 
 i .07046 
 
 9.66 
 
 12.2 
 
 1.04937 
 
 6.91 
 
 17.2 
 
 1.07090 
 
 9.72 
 
 12.3 
 
 1.04979 
 
 6.96 
 
 17.3 
 
 1.07133 
 
 9-77 
 
 12.4 
 
 1.05021 
 
 7.02 
 
 17.4 
 
 1.07177 
 
 9.83 
 
 12.5 
 
 1.05064 
 
 7.08 
 
 !7-5 
 
 1.07221 
 
 9.89 
 
 12.6 
 
 1.05106 
 
 7.13 
 
 17.6 
 
 1.07265 
 
 9-94 
 
 I2. 7 
 
 1.05149 
 
 7.19 
 
 17.7 
 
 1.07309 
 
 10.00 
 
 12.8 
 
 1.05191 
 
 7.24 
 
 17.8 
 
 1.07353 
 
 10. 06 
 
 12.9 
 
 1.05233 
 
 7-30 
 
 17.9 
 
 1.07397 
 
 10. II 
 
TABLES 
 
 287 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 17.5\ 
 GRAVITY \ 17 .5/ 
 
 DEGREES 
 BAUME 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 17.5\ 
 GRAVITY \ d m) 
 
 DEGREES 
 BAUME 
 
 18.0 
 
 1.07441 
 
 10.17 
 
 23.0 
 
 1.09686 
 
 12.96 
 
 18.1 
 
 1.07485 
 
 10.22 
 
 23.1 
 
 1.09732 
 
 13.02 
 
 18.2 
 
 1.07530 
 
 10.28 
 
 23.2 
 
 1.09777 
 
 13.07 
 
 18.3 
 
 1.07574 
 
 10.33 
 
 23-3 
 
 1.09823 
 
 13.13 
 
 18.4 
 
 1.07618 
 
 10.39 
 
 23-4 
 
 1.09869 
 
 I3.I9 
 
 18.5 
 
 1 .07662 
 
 10.45 
 
 23-5 
 
 1.09915 
 
 13.24 
 
 18.6 
 
 1.07706 
 
 10.50 
 
 23.6 
 
 1.09961 
 
 I3-30 
 
 18.7 
 
 1.07751 
 
 10.56 
 
 23-7 
 
 1.10007 
 
 13-35 
 
 18.8 
 
 1-07795 
 
 10.62 
 
 23.8 
 
 1.10053 
 
 I3-4I 
 
 18.9 
 
 1.07839 
 
 10.67 
 
 23-9 
 
 1.10099 
 
 13.46 
 
 19.0 
 
 1.07884 
 
 10.73 
 
 24.0 
 
 1.10145 
 
 I3-52 
 
 19.1 
 
 1.07928 
 
 10.78 
 
 24.1 
 
 1.10191 
 
 I3-58 
 
 19.2 
 
 1.07973 
 
 10.84 
 
 24.2 
 
 1.10237 
 
 13-03 
 
 19-3 
 
 1.08017 
 
 10.90 
 
 24-3 
 
 1.10283 
 
 13.69 
 
 19.4 
 
 1.08062 
 
 10.95 
 
 24.4 
 
 1 . 10329 
 
 13-74 
 
 19-5 
 
 1. 08106 
 
 II. 01 
 
 24-5 
 
 1-10375 
 
 13.80 
 
 19.6 
 
 1.08151 
 
 1 1. 06 
 
 24.6 
 
 1.10421 
 
 J 3-95 
 
 19.7 
 
 1.08196 
 
 II. 12 
 
 24-7 
 
 1.10468 
 
 13-91 
 
 19.8 
 
 1.08240 
 
 II.I8 
 
 24,8 
 
 1.10514 
 
 13.96 
 
 19.9 
 
 1.08285 
 
 11.23 
 
 24.9 
 
 1.10560 
 
 14.02 
 
 20.0 
 
 1.08329 
 
 11.29 
 
 25.0 
 
 1.10607 
 
 14.08 
 
 20.1 
 
 1.08374 
 
 "34 
 
 25.1 
 
 1.10653 
 
 14-13 
 
 20.2 
 
 1.08419 
 
 11.40 
 
 25.2 
 
 1.10700 
 
 14.19 
 
 20.3 
 
 1.08464 
 
 n-45 
 
 25-3 
 
 1.10746 
 
 14.24 
 
 20.4 
 
 1.08509 
 
 11.51 
 
 25-4 
 
 1.10793 
 
 14.30 
 
 20.5 
 
 1.08553 
 
 JI -57 
 
 25-5 
 
 1.10839 
 
 14-35 
 
 20.6 
 
 1.08599 
 
 11.62 
 
 25.6 
 
 1.10886 
 
 14.41 
 
 20.7 
 
 1.08643 
 
 11.68 
 
 25-7 
 
 1.10932 
 
 14.47 
 
 20.8 
 
 1.08688 
 
 "73 
 
 25.8 
 
 1.10979 
 
 14.52 
 
 20.9 
 
 1.08733 
 
 11.79 
 
 25-9 
 
 1.11026 
 
 14.58 
 
 21.0 
 
 1.08778 
 
 11.85 
 
 26.0 
 
 1.11072 
 
 14.63 
 
 21. 1 
 
 1.08824 
 
 11.90 
 
 26.1 
 
 1.11119 
 
 14.69 
 
 21.2 
 
 1.08869 
 
 11.96 
 
 26.2 
 
 1.11166 
 
 14.74 
 
 21.3 
 
 1.08914 
 
 12.01 
 
 26.3 
 
 1.11213 
 
 14.80 
 
 21. 4 
 
 1.08959 
 
 12.07 
 
 26.4 
 
 1.11259 
 
 14.85 
 
 21.5 
 
 1.09004 
 
 12.13 
 
 26.5 
 
 1.11306 
 
 14.91 
 
 21.6 
 
 1.09049 
 
 I2.I8 
 
 26.6 
 
 I-II353 
 
 14.97 
 
 21.7 
 
 1.09095 
 
 12.24 
 
 26.7 
 
 1.11400 
 
 15.02 
 
 21.8 
 
 1.09140 
 
 12.29 
 
 26.8 
 
 1.11447 
 
 15.08 
 
 21.9 
 
 1.09185 
 
 12-35 
 
 26.9 
 
 1.11494 
 
 15-13 
 
 22.0 
 
 1.09231 
 
 12.40 
 
 27.0 
 
 1.11541 
 
 ^3-^9 
 
 22.1 
 
 1.09276 
 
 12.46 
 
 27.1 
 
 1.11588 
 
 15.24 
 
 22.2 
 
 1.09321 
 
 12.52 
 
 27.2 
 
 1-11635 
 
 I5-30 
 
 22.3 
 
 1.09367 
 
 12-57 
 
 27-3 
 
 1.11682 
 
 J5-35 
 
 22. 4 
 
 1.09412 
 
 12.63 
 
 27-4 
 
 1.11729 
 
 i5-4i 
 
 22.5 
 
 1.09458 
 
 12.68 
 
 27.5 
 
 1.11776 
 
 1546 
 
 22.6 
 
 1.09503 
 
 12.74 
 
 27.6 
 
 1.11824 
 
 15-52 
 
 22.7 
 
 1.09549 
 
 12.80 
 
 27.7 
 
 1.11871 
 
 X 5.58 
 
 22.8 
 
 1-09595 
 
 12.85 
 
 27.8 
 
 1.11918 
 
 15.63 
 
 22.9 
 
 i .09640 
 
 12.91 
 
 27.9 
 
 1.11965 
 
 15.69 
 
288 
 
 TABLES 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 17.5\ 
 GRAVITY \ a 17.5/ 
 
 DEGREES 
 
 BAUME 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 17.5\ 
 GRAVITY V 17.5/ 
 
 DEGREES 
 BAUME 
 
 28.0 
 
 1.12013 
 
 15-74 
 
 33-o 
 
 1.14423 
 
 18.50 
 
 28.1 
 
 .12060 
 
 15.80 
 
 33-1 
 
 1.14472 
 
 18.56 
 
 28.2 
 
 .12107 
 
 15-85 
 
 33-2 
 
 1.14521 
 
 18.61 
 
 28.3 
 
 12155 
 
 I5-9I 
 
 33-3 
 
 1.14570 
 
 18.67 
 
 28.4 
 
 .12202 
 
 15.96 
 
 33-4 
 
 1.14620 
 
 18.72 
 
 28.5 
 
 .12250 
 
 16.02 
 
 33-5 
 
 1.14669 
 
 18.78 
 
 28.6 
 
 .12297 
 
 16.07 
 
 33-6 
 
 1.14718 
 
 18.83 
 
 28.7 
 
 12345 
 
 16.13 
 
 33-7 
 
 1.14767 
 
 18.89 
 
 28.8 
 
 I2 393 
 
 16.18 
 
 33-8 
 
 1.14817 
 
 18.94 
 
 28.9 
 
 .12440 
 
 16.24 
 
 33-9 
 
 1.14866 
 
 19.00 
 
 29.0 
 
 .12488 
 
 16.30 
 
 34-0 
 
 1.14915 
 
 19.05 
 
 29.1 
 
 12536 
 
 16.35 
 
 34-1 
 
 1.14965 
 
 19.11 
 
 29.2 
 
 12583 
 
 16.41 
 
 34-2 
 
 1.15014 
 
 19.16 
 
 29-3 
 
 .12631 
 
 16.46 
 
 34-3 
 
 1.15064 
 
 19.22 
 
 29.4 
 
 .12679 
 
 16.52 
 
 34-4 
 
 I.I5II3 
 
 19.27 
 
 29-5 
 
 .12727 
 
 16-57 
 
 34-5 
 
 1.15163 
 
 19-33 
 
 29.6 
 
 12775 
 
 16.63 
 
 34-6 
 
 1.15213 
 
 19.38 
 
 29.7 
 
 .12823 
 
 16.68 
 
 34-7 
 
 1.15262 
 
 19.44 
 
 29.8 
 
 .12871 
 
 16.74 
 
 34-8 
 
 1.15312 
 
 19.49 
 
 29.9 
 
 .12919 
 
 16.79 
 
 34-9 
 
 1.15362 
 
 19-55 
 
 30.0 
 
 .12967 
 
 16.85 
 
 35-o 
 
 1.15411 
 
 19.60 
 
 30.1 
 
 13015 
 
 16.90 
 
 35-1 
 
 1.15461 
 
 19.66 
 
 30.2 
 
 .13063 
 
 16.96 
 
 35-2 
 
 I.I55" 
 
 19.71 
 
 30.3 
 
 13111 
 
 17.01 
 
 35-3 
 
 I.I556I 
 
 19.76 
 
 3-4 
 
 I3IS9 
 
 17.07 
 
 35-4 
 
 1.15611 
 
 19.82 
 
 3-5 
 
 .13207 
 
 17.12 
 
 35-5 
 
 1.15661 
 
 19.87 
 
 30.6 
 
 I 3 2 55 
 
 17.18 
 
 35-6 
 
 1.15710 
 
 19.93 
 
 3-7 
 
 i33 4 
 
 17.23 
 
 35-7 
 
 1.15760 
 
 19.98 
 
 30.8 
 
 13352 
 
 17.29 
 
 35-8 
 
 1.15810 
 
 20.04 
 
 30-9 
 
 .13400 
 
 17-35 
 
 35-9 
 
 1.15861 
 
 20.09 
 
 31.0 
 
 13449 
 
 17.40 
 
 36.0 
 
 1.15911 
 
 20.15 
 
 3 1 - 1 
 
 13497 
 
 17.46 
 
 36.1 
 
 1.15961 
 
 20.20 
 
 31.2 
 
 13545 
 
 17.51 
 
 36.2 
 
 1. 16011 
 
 20.26 
 
 3*-3 
 
 13594 
 
 17-57 
 
 36.3 
 
 1. 16061 
 
 20.31 
 
 3 x -4 
 
 .13642 
 
 17.62 
 
 36-4 
 
 i.i6m 
 
 20.37 
 
 3*-5 
 
 .13691 
 
 17.68 
 
 36.5 
 
 1.16162 
 
 20.42 
 
 31.6 
 
 .13740 
 
 17*73 
 
 36.6 
 
 1.16212 
 
 20.48 
 
 3 J -7 
 
 .13788 
 
 17.79 
 
 36.7 
 
 1.16262 
 
 20.53 
 
 31-8 
 3 x -9 
 
 13837 
 13885 
 
 17.84 
 17.90 
 
 36.8 
 36-9 
 
 1.16313 
 1.16363 
 
 20.59 
 20.64 
 
 32.0 
 
 13934 
 
 17-95 
 
 37-o 
 
 1.16413 
 
 20.70 
 
 32.1 
 
 i39 8 3 
 
 18.01 
 
 37-i 
 
 1.16464 
 
 20.75 
 
 32.2 
 
 .14032 
 
 1 8. 06 
 
 37-2 
 
 1.16514 
 
 20.80 
 
 32.3 
 
 .14081 
 
 18.12 
 
 37-3 
 
 1.16565 
 
 20.86 
 
 32.4 
 
 .14129 
 
 18.17 
 
 37-4 
 
 1. 16616 
 
 20.91 
 
 3 2 -5 
 
 .14178 
 
 18.23 
 
 37-5 
 
 1.16666 
 
 20.97 
 
 32.6 
 
 .14227 
 
 18.28 
 
 37-6 
 
 1.16717 
 
 21.02 
 
 32.7 
 
 .14276 
 
 18.34 
 
 37-7 
 
 1.16768 
 
 21. 08 
 
 32.8 
 
 14325 
 
 18.39 
 
 37-8 
 
 1. 16818 
 
 21.13 
 
 32-9 
 
 14374 
 
 18.45 
 
 37-9 
 
 1.16869 
 
 21.19 
 
TABLES 
 
 289 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 17".5\ 
 GRAVITY \ a 17..V 
 
 DEGREES 
 BAUME 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 17.5\ 
 GRAVITY \ 17.57 
 
 DEGREES 
 
 BAUMlf 
 
 38.0 
 
 1.16920 
 
 21.24 
 
 43-0 
 
 LI9505 
 
 23.96 
 
 38.1 
 
 1.16971 
 
 21.30 
 
 43-1 
 
 LI9558 
 
 24.01 
 
 38.2 
 
 1.17022 
 
 2L35 
 
 43-2 
 
 1.19611 
 
 24.07 
 
 38.3 
 
 1.17072 
 
 21.40 
 
 43-3 
 
 .19663 
 
 24.12 
 
 38.4 
 
 1.17123 
 
 21.46 
 
 43-4 
 
 .19716 
 
 24.17 
 
 38.5 
 
 1.17174 
 
 21.51 
 
 43-5 
 
 .19769 
 
 24.23 
 
 38.6 
 
 1.17225 
 
 21-57 
 
 43-6 
 
 .19822 
 
 24.28 
 
 38.7 
 
 1.17276 
 
 21.62 
 
 43-7 
 
 .19875 
 
 24-34 
 
 38.8 
 
 1.17327 
 
 21.68 
 
 43-8 
 
 .19927 
 
 24.39 
 
 38.9 
 
 1.17379 
 
 21.73 
 
 43-9 
 
 .19980 
 
 24.44 
 
 39-o 
 
 1.17430 
 
 21.79 
 
 44.0 
 
 .20033 
 
 24.50 
 
 39-1 
 
 1.17481 
 
 21.84 
 
 44.1 
 
 .20086 
 
 24.55 
 
 39-2 
 
 LI7532 
 
 21.90 
 
 44.2 
 
 .20139 
 
 24.61 
 
 39-3 
 
 LI7583 
 
 21.95 
 
 44-3 
 
 .20192 
 
 24.66 
 
 39-4 
 
 LI7635 
 
 22.00 
 
 44-4 
 
 20245 
 
 24.71 
 
 39-5 
 
 1.17686 
 
 22.O6 
 
 44-5 
 
 .20299 
 
 24.77 
 
 39-6 
 
 1.17737 
 
 22.11 
 
 44-6 
 
 .20352 
 
 24.82 
 
 39-7 
 
 1.17789 
 
 22.17 
 
 44-7 
 
 .20405 
 
 24.88 
 
 39-8 
 
 1 . 17840 
 
 22.22 
 
 44.8 
 
 .20458 
 
 24.93 
 
 39-9 
 
 1.17892 
 
 22.28 
 
 44-9 
 
 .20512 
 
 24.98 
 
 40,0 
 
 I-I7943 
 
 22.33 
 
 45-o 
 
 .20565 
 
 25.04 
 
 40.1 
 
 I-I7995 
 
 22.38 
 
 45-1 
 
 .20618 
 
 25.09 
 
 40.2 
 
 1.18046 
 
 22.44 
 
 45-2 
 
 .20672 
 
 25.14 
 
 40.3 
 
 1.18098 
 
 22.49 
 
 45-3 
 
 20725 
 
 25.20 
 
 40.4 
 
 1.18150 
 
 22.55 
 
 45-4 
 
 .20779 
 
 25.25 
 
 40-5 
 
 1.18201 
 
 22.60 
 
 45-5 
 
 .20832 
 
 25-31 
 
 40.6 
 
 1.18253 
 
 22.66 
 
 45-6 
 
 .20886 
 
 25-36 
 
 40.7 
 
 1.18305 
 
 22.71 
 
 45-7 
 
 .20939 
 
 25.41 
 
 40.8 
 
 LI8357 
 
 22.77 
 
 45-8 
 
 .20993 
 
 25.47 
 
 40.9 
 
 1.18408 
 
 22.82 
 
 45-9 
 
 .21046 
 
 25.52 
 
 41.0 
 
 1.18460 
 
 22.87 
 
 46.0 
 
 .21100 
 
 25-57 
 
 41.1 
 
 1.18512 
 
 22.93 
 
 46.1 
 
 .21154 
 
 25.63 
 
 41.2 
 
 1.18564 
 
 22.98 
 
 46.2 
 
 .21208 
 
 25.68 
 
 41-3 
 
 1. 18616 
 
 23.04 
 
 46-3 
 
 .21261 
 
 25.74 
 
 41.4 
 
 1.18668 
 
 23.09 
 
 46.4 
 
 .21315 
 
 25.79 
 
 4i-5 
 
 1.18720 
 
 23.15 
 
 46.5 
 
 21369 
 
 25.84 
 
 41.6 
 
 1.18772 
 
 23.20 
 
 46.6 
 
 .21423 
 
 25.90 
 
 41.7 
 
 1.18824 
 
 23.25 
 
 46-7 
 
 .21477 
 
 25.95 
 
 41.8 
 
 1.18877 
 
 23.31 
 
 46.8 
 
 .21531 
 
 26.00 
 
 41.9 
 
 1.18929 
 
 23.36 
 
 46.9 
 
 .2I 5 85 
 
 26.06 
 
 42.0 
 
 1.18981 
 
 23.42 
 
 47.0 
 
 .21639 
 
 26.11 
 
 42.1 
 
 1.19033 
 
 23.47 
 
 47.1 
 
 .21693 
 
 26.17 
 
 42.2 
 
 1.19086 
 
 23.52 
 
 47.2 
 
 21747 
 
 26.22 
 
 4 2 -3 
 
 I 19138 
 
 23.58 
 
 47.3 
 
 .2l802 
 
 26.27 
 
 42.4 
 
 1.19190 
 
 23.63 
 
 47-4 
 
 .21856 
 
 26.33 
 
 42.5 
 
 1.19243 
 
 23.69 
 
 47-5 
 
 .2I9IO 
 
 26.38 
 
 42.6 
 
 1.19295 
 
 23.74 
 
 47-6 
 
 .21964 
 
 26.43 
 
 42-7 
 
 1.19348 
 
 23.79 
 
 47-7 
 
 .22019 
 
 26.49 
 
 42.8 
 
 1.19400 
 
 23.85 
 
 47.8 
 
 22073 
 
 26.54 
 
 42.9 
 
 I-I9453 
 
 23.90 
 
 47-9 
 
 .22127 
 
 26.59 
 
290 
 
 TABLES 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 17.5\ 
 GRAVITY \ a u.5/ 
 
 DEGREES 
 BAUME 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 17.5\ 
 GRAVITY \ 17.57 
 
 DEGREES 
 BAUME 
 
 48.0 
 
 1.22182 
 
 26.65 
 
 53-0 
 
 1.24951 
 
 29.31 
 
 48.1 
 
 1.22236 
 
 26.70 
 
 53-1 
 
 1.25008 
 
 29.36 
 
 48.2 
 
 1.22291 
 
 26.75 
 
 53-2 
 
 1.25064 
 
 29.42 
 
 48.3 
 
 1-22345 
 
 26.81 
 
 53-3 
 
 1.25120 
 
 29-47 
 
 48.4 
 
 1.22400 
 
 26.86 
 
 534 
 
 1.25177 
 
 29-52 
 
 48.5 
 
 1-22455 
 
 26.92 
 
 53-5 
 
 1.25233 
 
 29-57 
 
 48.6 
 
 1.22509 
 
 26.97 
 
 53-6 
 
 1.25290 
 
 29.63 
 
 48.7 
 
 1.22564 
 
 27.02 
 
 53-7 
 
 1-25347 
 
 29.68 
 
 48.8 
 
 1.22619 
 
 27.08 
 
 53-8 
 
 1.25403 
 
 29-73 
 
 48.9 
 
 1.22673 
 
 27.13 
 
 53-9 
 
 1.25460 
 
 29-79 
 
 49.0 
 
 1.22728 
 
 27.18 
 
 54-0 
 
 I.255I7 
 
 29.84 
 
 49.1 
 
 1.22783 
 
 27.24 
 
 54-i 
 
 1-25573 
 
 29.89 
 
 49.2 
 
 1.22838 
 
 27.29 
 
 54-2 
 
 1.25630 
 
 29.94 
 
 49-3 
 
 1.22893 
 
 27-34 
 
 54-3 
 
 1.25687 
 
 30.00 
 
 49.4 
 
 1.22948 
 
 27.40 
 
 54-4 
 
 1.25744 
 
 3-5 
 
 49-5 
 
 1.23003 
 
 27-45 
 
 54-5 
 
 1.25801 
 
 30.10 
 
 49.6 
 
 1.23058 
 
 27.50 
 
 54- 6 
 
 1.25857 
 
 30.16 
 
 49-7 
 
 1.23113 
 
 27.56 
 
 54-7 
 
 1.25914 
 
 30.21 
 
 49.8 
 
 1.23168 
 
 27.61 
 
 54-8 
 
 1.25971 
 
 30.26 
 
 49-9 
 
 1.23223 
 
 27.66 
 
 54-9 
 
 1.26028 
 
 30-31 
 
 50.0 
 
 1.23278 
 
 27.72 
 
 55-0 
 
 1.26086 
 
 30.37 
 
 50.1 
 
 1-23334 
 
 27.77 
 
 55-i 
 
 1.26143 
 
 30.42 
 
 50.2 
 
 1.23389 
 
 27.82 
 
 55-2 
 
 1.26200 
 
 30.47 
 
 50.3 
 
 1.23444 
 
 27.88 
 
 55-3 
 
 1.26257 
 
 30.53 
 
 5o.4 
 
 1.23499 
 
 27.93 
 
 55-4 
 
 1.26314 
 
 30-58 
 
 50-5 
 
 1.23555 
 
 27.98 
 
 55-5 
 
 1.26372 
 
 30.63 
 
 50.6 
 
 1.23610 
 
 28.04 
 
 55-6 
 
 1.26429 
 
 30.68 
 
 50-7 
 
 1.23666 
 
 28.09 
 
 55-7 
 
 1.26486 
 
 30.74 
 
 50.8 
 
 1.23721 
 
 28.14 
 
 55-8 
 
 1.26544 
 
 30.79 
 
 50-9 
 
 1.23777 
 
 28.20 
 
 55-9 
 
 1.26601 
 
 30.84 
 
 51.0 
 
 1.23832 
 
 28.25 
 
 56.0 
 
 1.26658 
 
 30.89 
 
 5 1 - 1 
 
 1.23888 
 
 28.30 
 
 56.1 
 
 1.26716 
 
 30.95 
 
 5 1 - 2 
 
 1.23943 
 
 28.36 
 
 56.2 
 
 1.26773 
 
 31.00 
 
 5 J -3 
 
 1.23999 
 
 28.41 
 
 56-3 
 
 1.26831 
 
 31-05 
 
 5^4 
 
 1.24055 
 
 28.46 
 
 56.4 
 
 1.26889 
 
 31.10 
 
 5 J -5 
 
 1.24111 
 
 28.51 
 
 56.5 
 
 1.26946 
 
 31.16 
 
 51-6 
 
 1.24166 
 
 28.57 
 
 56.6 
 
 1.27004 
 
 31.21 
 
 S*'7 
 
 1.24222 
 
 28.62 
 
 56.7 
 
 1.27062 
 
 31.26 
 
 51-8 
 
 1.24278 
 
 28.67 
 
 56.8 
 
 1.27120 
 
 3i-3i 
 
 Si-9 
 
 1-24334 
 
 28.73 
 
 56-9 
 
 1.27177 
 
 31-37 
 
 52.0 
 
 1.24390 
 
 28.78 
 
 57-0 
 
 1.27235 
 
 3142 
 
 52-1 
 
 1.24446 
 
 28.83 
 
 57-i 
 
 1.27293 
 
 31-47 
 
 52.2 
 
 1.24502 
 
 28.89 
 
 57-2 
 
 I.2735I 
 
 31-52 
 
 52.3 
 
 1.24558 
 
 28.94 
 
 57-3 
 
 1.27409 
 
 3I-58 
 
 52.4 
 
 1.24614 
 
 28.99 
 
 57-4 
 
 1.27467 
 
 31-63 
 
 52.5 
 
 1.24670 
 
 29.05 
 
 57-5 
 
 1-27525 
 
 31.68 
 
 52.6 
 
 1.24726 
 
 29.10 
 
 57-6 
 
 1-27583 
 
 31-73 
 
 52.7 
 
 1.24782 
 
 29.15 
 
 57-7 
 
 1.27641 
 
 31.79 
 
 52.8 
 
 1.24839 
 
 29.20 
 
 57-8 
 
 1.27699 
 
 31.84 
 
 52-9 
 
 1.24895 
 
 29.26 
 
 57-9 
 
 1.27758 
 
 31-89 
 
TABLES 
 
 291 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / . 17.5\ 
 GRAVITY \ 17.5/ 
 
 DEGREES 
 BAUME 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / r 17.5\ 
 GRAVITY \ 17.5/ 
 
 DEGREES 
 BAUME 
 
 58.0 
 
 1.27816 
 
 31-94 
 
 63.0 
 
 1.30777 
 
 34-54 
 
 58.1 
 
 1.27874 
 
 32.00 
 
 63-1 
 
 1.30837 
 
 34-59 
 
 58.2 
 
 1.27932 
 
 32.05 
 
 63.2 
 
 1.30897 
 
 34-65 
 
 58.3 
 
 1.27991 
 
 32.10 
 
 63-3 
 
 1.30958 
 
 34-70 
 
 58.4 
 
 1.28049 
 
 32.15 
 
 63-4 
 
 1.31018 
 
 34-75 
 
 58.5 
 
 1.28107 
 
 32.20 
 
 63-5 
 
 1.31078 
 
 34-80 
 
 58.6 
 
 1.28166 
 
 32.26 
 
 63.6 
 
 I.3H39 
 
 34-85 
 
 58.7 
 
 1.28224 
 
 32.31 
 
 63-7 
 
 1.31199 
 
 34-90 
 
 58.8 
 
 1.28283 
 
 32-36 
 
 63.8 
 
 1.31260 
 
 34-96 
 
 58.9 
 
 1.28342 
 
 32.41 
 
 63-9 
 
 1.31320 
 
 35-01 
 
 59-0 
 
 1.28400 
 
 32.47 
 
 64.0 
 
 1.31381 
 
 35.o6 
 
 59-1 
 
 1.28459 
 
 32.52 
 
 64.1 
 
 1.31442 
 
 35." 
 
 59-2 
 
 1.28518 
 
 32.57 
 
 64.2 
 
 1.31502 
 
 35-16 
 
 59-3 
 
 1.28576 
 
 32.62 
 
 64-3 
 
 1-31563 
 
 35-21 
 
 59-4 
 
 1.28635 
 
 32.67 
 
 64.4 
 
 1.31624 
 
 35-27 
 
 59-5 
 
 1.28694 
 
 32.73 
 
 64-5 
 
 1.31684 
 
 35-32 
 
 59-6 
 
 1-28753 
 
 32.78 
 
 64.6 
 
 L3I745 
 
 35-37 
 
 59-7 
 
 1.28812 
 
 32.83 
 
 64.7 
 
 1.31806 
 
 35.42 
 
 59-8 
 
 1.28871 
 
 32.88 
 
 64.8 
 
 1.31867 
 
 35-47 
 
 59-9 
 
 1.28930 
 
 32.93 
 
 64.9 
 
 1.31928 
 
 35-52 
 
 60.0 
 
 1.28989 
 
 32.99 
 
 65.0 
 
 1.31989 
 
 35-57 
 
 60. i 
 
 1.29048 
 
 33-04 
 
 65-1 
 
 1.32050 
 
 35.63 
 
 60.2 
 
 1.29107 
 
 33.09 
 
 65.2 
 
 1.32111 
 
 35-68 
 
 60.3 
 
 1.29166 
 
 33-14 
 
 65-3 
 
 1.32172 
 
 35-73 
 
 60.4 
 
 1.29225 
 
 33-20 
 
 65-4 
 
 1.32233 
 
 35-78 
 
 60.5 
 
 1.29284 
 
 33-25 
 
 65-5 
 
 1.32294 
 
 35.83 
 
 60.6 
 
 L29343 
 
 33.30 
 
 65.6 
 
 I.32355 
 
 35-88 
 
 60.7 
 
 1.29403 
 
 33-35 
 
 65-7 
 
 1.32417 
 
 35-93 
 
 60.8 
 
 1.29462 
 
 33-40 
 
 65.8 
 
 1.32478 
 
 35-98 
 
 60.9 
 
 1.29521 
 
 33-46 
 
 65.9 
 
 1-32539 
 
 36.04 
 
 61.0 
 
 1.29581 
 
 33 -5 1 
 
 66.0 
 
 1.32601 
 
 36.09 
 
 61.1 
 
 1.29640 
 
 33.56 
 
 66.1 
 
 1.32662 
 
 36.14 
 
 61.2 
 
 1.29700 
 
 33-61 
 
 66.2 
 
 1.32724 
 
 36.19 
 
 61.3 
 
 1.29759 
 
 33-66 
 
 66.3 
 
 1-32785 
 
 36.24 
 
 61.4 
 
 1.29819 
 
 33-71 
 
 66.4 
 
 1.32847 
 
 36.29 
 
 61-5 
 
 1.29878 
 
 33-77 
 
 66.5 
 
 1.32908 
 
 36.34 
 
 61.6 
 
 1.29938 
 
 33-82 
 
 66.6 
 
 1.32970 
 
 36.39 
 
 61.7 
 
 1.29998 
 
 33.87 
 
 66.7 
 
 1.33031 
 
 36.45 
 
 61.8 
 
 1.30057 
 
 33-92 
 
 66.8 
 
 L33093 
 
 36-50 
 
 61.9 
 
 1.30117 
 
 33-97 
 
 66.9 
 
 I.33I55 
 
 36.55 
 
 62.0 
 
 1.30177 
 
 34.03 
 
 67.0 
 
 1.33217 
 
 36.60 
 
 62.1 
 
 1.30237 
 
 34.08 
 
 67.1 
 
 1,33278 
 
 36.65 
 
 62.2 
 
 1.30297 
 
 34-13 
 
 67.2 
 
 1-33340 
 
 36.70 
 
 62.3 
 
 1.30356 
 
 34.18 
 
 67-3 
 
 1.33402 
 
 36.75 
 
 62.4 
 
 1.30416 
 
 34-23 
 
 67-4 
 
 1.33464 
 
 36.80 
 
 62.5 
 
 1.30476 
 
 34.28 
 
 67-5 
 
 1.33526 
 
 36-85 
 
 62.6 
 
 1.30536 
 
 34-34 
 
 67.6 
 
 1.33588 
 
 36-90 
 
 62.7 
 
 1.30596 
 
 34-39 
 
 67-7 
 
 1.33650 
 
 36.96 
 
 62.8 
 
 1.30657 
 
 34-44 
 
 67.8 
 
 1.33712 
 
 37.01 
 
 62.9 
 
 1.30717 
 
 34-49 
 
 67.9 
 
 1-33774 
 
 37-06 
 
TABLES 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / . 17-5\ 
 GRAVITY \ 17.5/ 
 
 DEGREES 
 BAUME 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , l"-5\ 
 GRAVITY \ 17.57 
 
 DEGREES 
 BAUME" 
 
 68.0 
 
 1.33836 
 
 37-11 
 
 73.o 
 
 1.36995 
 
 39-64 
 
 68.1 
 
 1.33899 
 
 37.16 
 
 73.1 
 
 1.37059 
 
 39-69 
 
 68.2 
 
 1.33961 
 
 37.21 
 
 73-2 
 
 1.37124 
 
 39-74 
 
 68.3 
 
 1.34023 
 
 37.26 
 
 73-3 
 
 I-37I88 
 
 39-79 
 
 68.4 
 
 1.34085 
 
 37.31 
 
 73-4 
 
 1.37252 
 
 39.84 
 
 68.5 
 
 1.34148 
 
 37-36 
 
 73-5 
 
 I-373I7 
 
 39.89 
 
 68.6 
 
 1.34210 
 
 3741 
 
 73-6 
 
 I-3738I 
 
 39-94 
 
 68.7 
 
 1.34273 
 
 37-47 
 
 73-7 
 
 1.37446 
 
 39-99 
 
 68.8 
 
 1-34335 
 
 37.52 
 
 73-8 
 
 I-375IO 
 
 40.04 
 
 68.9 
 
 1.34398 
 
 37-57 
 
 73-9 
 
 1-37575 
 
 40.09 
 
 69.0 
 
 1.34460 
 
 37-62 
 
 74-o 
 
 1.37639 
 
 40.14 
 
 69.1 
 
 1.34523 
 
 37-67 
 
 74.1 
 
 1.37704 
 
 40.19 
 
 69.2 
 
 1.34585 
 
 37-72 
 
 74-2 
 
 1.37768 
 
 40.24 
 
 69.3 
 
 1.34648 
 
 37-77 
 
 74-3 
 
 1-37833 
 
 40.29 
 
 60.4 
 
 1-347" 
 
 37.82 
 
 74-4 
 
 1.37898 
 
 40.34 
 
 69.5 
 
 1.34774 
 
 37.87 
 
 74-5 
 
 1.37962 
 
 40.39 
 
 69.6 
 
 1.34836 
 
 37.92 
 
 74-6 
 
 1.38027 
 
 40.44 
 
 69.7 
 
 1.34899 
 
 37-97 
 
 74-7 
 
 1.38092 
 
 40.49 
 
 69.8 
 
 1.34962 
 
 38.02 
 
 74-8 
 
 1-38157 
 
 40.54 
 
 69.9 
 
 1-35025 
 
 38.07 
 
 74-9 
 
 1.38222 
 
 40.59 
 
 70.0 
 
 1.35088 
 
 38.12 
 
 75-o 
 
 1.38287 
 
 40.64 
 
 70.1 
 
 I-35I5I 
 
 38.18 
 
 75-i 
 
 1.38352 
 
 40.69 
 
 70.2 
 
 L352I4 
 
 38.23 
 
 75-2 
 
 1.38417 
 
 40.74 
 
 70-3 
 
 I.35277 
 
 38.28 
 
 75-3 
 
 1.38482 
 
 40.79 
 
 70.4 
 
 1 -35340 
 
 38.33 
 
 75-4 
 
 I.38547 
 
 40.84 
 
 70-5 
 
 1.35403 
 
 38.38 
 
 75-5 
 
 1.38612 
 
 40.89 
 
 70.6 
 
 1.35466 
 
 38.43 
 
 75-6 
 
 1.38677 
 
 40.94 
 
 70.7 
 
 1-35530 
 
 38-48 
 
 75-7 
 
 L38743 
 
 40.99 
 
 70.8 
 
 1.35593 
 
 38.53 
 
 75-8 
 
 1.38808 
 
 41.04 
 
 70.9 
 
 1.35656 
 
 38.58 
 
 75-9 
 
 1.38873 
 
 41.09 
 
 71.0 
 
 1.35720 
 
 38-63 
 
 76.0 
 
 1.38939 
 
 41.14 
 
 71.1 
 
 i'35783 
 
 38.68 
 
 76.1 
 
 1.39004 
 
 41.19 
 
 71.2 
 
 1.35847 
 
 38.73 
 
 76.2 
 
 1.39070 
 
 41.24 
 
 71.3 
 
 i.359io 
 
 38.78 
 
 76.3 
 
 L39I35 
 
 41.29 
 
 71.4 
 71-5 
 
 1-35974 
 1.36037 
 
 38-83 
 38.88 
 
 76.4 
 76.5 
 
 1.39201 
 1.39266 
 
 41-33 
 41.38 
 
 71.6 
 
 1.36101 
 
 38.93 
 
 76.6 
 
 1.39332 
 
 4*-43 
 
 71.7 
 
 1.36164 
 
 38.98 
 
 76.7 
 
 1-39397 
 
 41.48 
 
 71.8 
 
 1.36228 
 
 39-03 
 
 76.8 
 
 1.39463 
 
 4L53 
 
 71.9 
 
 1.36292 
 
 39-o8 
 
 76.9 
 
 1.39529 
 
 41.58 
 
 72.0 
 
 1.36355 
 
 39-13 
 
 77-0 
 
 1-39595 
 
 41.63 
 
 72.1 
 
 1.36419 
 
 39-19 
 
 77.1 
 
 1.39660 
 
 41.68 
 
 72.2 
 
 1.36483 
 
 39-24 
 
 77-2 
 
 1.39726 
 
 41-73 
 
 72-3 
 
 1.36547 
 
 39-29 
 
 77-3 
 
 1.39792 
 
 41.78 
 
 72.4 
 
 1.36611 
 
 39-34 
 
 77-4 
 
 1.39858 
 
 41.83 
 
 7 2 -5 
 
 1.36675 
 
 39-39 
 
 77-5 
 
 1.39924 
 
 41.88 
 
 72.6 
 
 1.36739 
 
 39-44 
 
 77-6 
 
 1.39990 
 
 41-93 
 
 72.7 
 
 1.36803 
 
 39-49 
 
 77-7 
 
 1.40056 
 
 41.98 
 
 72.8 
 
 1.36867 
 
 39-54 
 
 77.8 
 
 1.40122 
 
 42.03 
 
 72.9 
 
 1.36931 
 
 39-59 
 
 779 
 
 i 40188 
 
 42.08 
 
TABLES 
 
 293 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 1^\ 
 GRAVITY \ 17.5/ 
 
 DEGREES 
 BAUME 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 17.5\ 
 GRAVITY \ 17.57 
 
 DEGREES 
 BAUME 
 
 78.0 
 
 1.40254 
 
 42.13 
 
 83.0 
 
 1.43614 
 
 44.58 
 
 78.1 
 
 1.40321 
 
 42.18 
 
 83.1 
 
 1.43682 
 
 44.62 
 
 78.2 
 
 1.40387 
 
 42.23 
 
 83-2 
 
 1.43750 
 
 44.67 
 
 78.3 
 
 L404S3 
 
 42.28 
 
 83.3 
 
 I.438I9 
 
 44.72 
 
 78.4 
 
 1.40520 
 
 42.32 
 
 834 
 
 1.43887 
 
 44-77 
 
 78.5 
 
 1.40586 
 
 42.37 
 
 83.5 
 
 1-43955 
 
 44.82 
 
 78.6 
 
 1.40652 
 
 42.42 
 
 83.6 
 
 1.44024 
 
 44.87 
 
 78.7 
 
 1.40719 
 
 42.47 
 
 83.7 
 
 1.44092 
 
 44.91 
 
 78.8 
 
 1.40785 
 
 42.52 
 
 83.8 
 
 1.44161 
 
 44.96 
 
 78.9 
 
 1.40852 
 
 42-57 
 
 83.9 
 
 1.44229 
 
 45.01 
 
 79.0 
 
 1.40918 
 
 42.62 
 
 84.0 
 
 1.44298 
 
 45.06 
 
 79.1 
 
 1.40985 
 
 42.67 
 
 84.1 
 
 1.44367 
 
 45.ii 
 
 79.2 
 
 1.41052 
 
 42.72 
 
 84.2 
 
 1.44435 
 
 45.16 
 
 79-3 
 
 1.41118 
 
 42.77 
 
 84.3 
 
 1.44504 
 
 45.21 
 
 79-4 
 
 1.41185 
 
 42.82 
 
 84.4 
 
 1-44573 
 
 45.25 
 
 79-5 
 
 1.41252 
 
 42.87 
 
 84.5 
 
 1.44641 
 
 45-30 
 
 79.6 
 
 1.41318 
 
 42.92 
 
 84.6 
 
 1.44710 
 
 45-35 
 
 79-7 
 
 I.4I385 
 
 42.96 
 
 84-7 
 
 1.44779 
 
 4540 
 
 79-8 
 
 1.41452 
 
 43.01 
 
 84.8 
 
 1.44848 
 
 4545 
 
 79-9 
 
 1.41519 
 
 43.06 
 
 84.9 
 
 1.44917 
 
 45-49 
 
 80.0 
 
 1.41586 
 
 43-11 
 
 85.0 
 
 1.44986 
 
 45-54 
 
 80. i 
 
 1-41653 
 
 43.16 
 
 85.1 
 
 145055 
 
 45-59 
 
 80.2 
 
 1.41720 
 
 43.21 
 
 85.2 
 
 1.45124 
 
 45-64 
 
 80.3 
 
 1.41787 
 
 43.26 
 
 85-3 
 
 I.45I93 
 
 45.69 
 
 80.4 
 
 1.41854 
 
 43.31 
 
 85.4 
 
 1.45262 
 
 45.74 
 
 80.5 
 
 1.41921 
 
 43.36 
 
 85.5 
 
 L4533I 
 
 45.78 
 
 80.6 
 
 1.41989 
 
 43-41 
 
 85.6 
 
 1.45401 
 
 45.83 
 
 80.7 
 
 1.42056 
 
 43-45 
 
 85.7 
 
 1.45470 
 
 45-88 
 
 80.8 
 
 1.42123 
 
 43-50 
 
 85-8 
 
 1.45539 
 
 45-93 
 
 80.9 
 
 1.42190 
 
 43-55 
 
 85-9 
 
 1.45609 
 
 45-98 
 
 81.0 
 
 1.42258 
 
 43.6o 
 
 86.0 
 
 1.45678 
 
 46.02 
 
 81.1 
 
 1.42325 
 
 43.65 
 
 86.1 
 
 1.45748 
 
 46.07 
 
 81.2 
 
 1.42393 
 
 43-70 
 
 86.2 
 
 1.45817 
 
 46.12 
 
 81.3 
 
 1.42460 
 
 43-75 
 
 86.3 
 
 1.45887 
 
 46.17 
 
 81.4 
 
 1.42528 
 
 43.80 
 
 86.4 
 
 L45956 
 
 46.22 
 
 81.5 
 
 1.42595 
 
 43.85 
 
 86.5 
 
 1.46026 
 
 46.26 
 
 81.6 
 
 1.42663 
 
 43.89 
 
 86.6 
 
 1.46095 
 
 46.31 
 
 81.7 
 
 1.42731 
 
 43-94 
 
 86.7 
 
 1.46165 
 
 46.36 
 
 81.8 
 
 1.42798 
 
 43-99 
 
 86.8 
 
 1.46235 
 
 46.41 
 
 81.9 
 
 1.42866 
 
 44.04 
 
 86.9 
 
 1 .46304 
 
 46.46 
 
 82.0 
 
 1.42934 
 
 44.09 
 
 87.0 
 
 1.46374 
 
 46.50 
 
 82.1 
 
 1.43002 
 
 44.14 
 
 87.1 
 
 1.46444 
 
 46.55 
 
 82.2 
 
 1.43070 
 
 44.19 
 
 87.2 
 
 1.46514 
 
 46.60 
 
 82.3 
 
 L43I37 
 
 44.24 
 
 87-3 
 
 1.46584 
 
 46.65 
 
 82.4 
 
 1.43205 
 
 44.28 
 
 87.4 
 
 1.46654 
 
 46.69 
 
 82.5 
 
 L43273 
 
 44.33 
 
 87.5 
 
 1.46724 
 
 46.74 
 
 82.6 
 
 L4334I 
 
 44.38 
 
 87.6 
 
 1.46794 
 
 46.79 
 
 82.7 
 
 1.43409 
 
 44-43 
 
 87.7 
 
 1.46864 
 
 46.84 
 
 82.8 
 
 1.43478 
 
 44.48 
 
 87.8 
 
 1.46934 
 
 46.88 
 
 82.9 
 
 I-43546 
 
 44-53 
 
 87.9 
 
 1.47004 
 
 46.93 
 
294 
 
 TABLES 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / . 17.5\ 
 GRAVITY \ a 17.5/ 
 
 DEGREES 
 BAUME 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / 17.5\ 
 GRAVITY \ a 17.5/ 
 
 DEGREES 
 BAUME 
 
 88.0 
 
 1.47074 
 
 46.98 
 
 93.0 
 
 L50635 
 
 49-34 
 
 88.1 
 
 I-47I45 
 
 47.03 
 
 93-1 
 
 1.50707 
 
 49-39 
 
 88.2 
 
 I.472I5 
 
 47.08 
 
 93.2 
 
 1.50779 
 
 49-43 
 
 88.3 
 
 1.47285 
 
 47.12 
 
 93-3 
 
 1.50852 
 
 4948 
 
 88.4 
 
 I.47356 
 
 47- 17 
 
 93-4 
 
 1.50924 
 
 49-53 
 
 88.5 
 
 1.47426 
 
 47.22 
 
 93-5 
 
 1.50996 
 
 49-57 
 
 88.6 
 
 1.47496 
 
 47.27 
 
 93-6 
 
 1.51069 
 
 49.62 
 
 88.7 
 
 1.47567 
 
 47.31 
 
 93-7 
 
 1.51141 
 
 49.67 
 
 88.8 
 
 1.47637 
 
 47-36 
 
 93-8 
 
 1.51214 
 
 49.71 
 
 88.9 
 
 1.47708 
 
 47.41 
 
 93-9 
 
 1.51286 
 
 49.76 
 
 89.0 
 
 1.47778 
 
 47.46 
 
 94.0 
 
 L5I359 
 
 49.81 
 
 8 9 .i 
 
 1.47849 
 
 47-50 
 
 94.1 
 
 L5I43I 
 
 49.85 
 
 89.2 
 
 1.47920 
 
 47-55 
 
 94.2 
 
 I -5 I 54 
 
 49.90 
 
 89.3 
 
 1.47991 
 
 47.60 
 
 94-3 
 
 L5I577 
 
 49.94 
 
 89.4 
 
 1.48061 
 
 47.65 
 
 94-4 
 
 1.51649 
 
 49-99 
 
 89-5 
 
 1.48132 
 
 47.69 
 
 94-5 
 
 1.51722 
 
 50.04 
 
 89.6 
 
 1.48203 
 
 47-74 
 
 94.6 
 
 I.5I795 
 
 50.08 
 
 89.7 
 
 1.48274 
 
 47-79 
 
 94-7 
 
 1.51868 
 
 S -^ 
 
 89.8 
 
 1.48345 
 
 47.83 
 
 94-8 
 
 1.51941 
 
 50.18 
 
 89.9 
 
 1.48416 
 
 47.88 
 
 94-9 
 
 1.52014 
 
 50.22 
 
 90.0 
 
 1.48486 
 
 47-93 
 
 95-o 
 
 1.52087 
 
 50.27 
 
 90.1 
 
 1.48558 
 
 47.98 
 
 95-1 
 
 1.52159 
 
 50.32 
 
 90.2 
 
 1.48629 
 
 48.02 
 
 95-2 
 
 1.52232 
 
 50.36 
 
 90.3 
 
 1.48700 
 
 48.07 
 
 95-3 
 
 1.52304 
 
 50.41 
 
 90.4 
 
 1.48771 
 
 48.12 
 
 95-4 
 
 1.52376 
 
 50.45 
 
 90.S 
 
 1.48842 
 
 48.17 
 
 95-5 
 
 1.52449 
 
 50.50 
 
 90.6 
 
 1.48913 
 
 48.21 
 
 95-6 
 
 1.52521 
 
 50.55 
 
 90.7 
 
 1.48985 
 
 48.26 
 
 95-7 
 
 1.52593 
 
 50.59 
 
 90.8 
 
 1.49056 
 
 48.31 
 
 95-8 
 
 1.52665 
 
 50.64 
 
 90.9 
 
 1.49127 
 
 48.35 
 
 95-9 
 
 1.52738 
 
 50.69 
 
 91.0 
 
 1.49199 
 
 48.40 
 
 96.0 
 
 1.52810 
 
 50.73 
 
 91.1 
 
 1.49270 
 
 48.45 
 
 96.1 
 
 1.52884 
 
 50.78 
 
 91.2 
 
 1.49342 
 
 48.50 
 
 96.2 
 
 1.52958 
 
 50.82 
 
 91-3 
 
 1.49413 
 
 48.54 
 
 96.3 
 
 1-53032 
 
 50.87 
 
 91.4 
 
 1.49485 
 
 48.59 
 
 96-4 
 
 1.53106 
 
 50.92 
 
 91-5 
 
 I.49556 
 
 48.64 
 
 96.5 
 
 1.53180 
 
 50.96 
 
 91.6 
 
 i .49628 
 
 48.68 
 
 96.6 
 
 1.53254 
 
 51.01 
 
 91.7 
 
 1.49700 
 
 48.73 
 
 96.7 
 
 I.53328 
 
 5L05 
 
 91.8 
 
 1.49771 
 
 48.78 
 
 96.8 
 
 1.53402 
 
 51.10 
 
 91.9 
 
 1-49843 
 
 48.82 
 
 96-9 
 
 1.53476 
 
 5LI5 
 
 92.0 
 
 1.49915 
 
 48.87 
 
 97.0 
 
 1.53550 
 
 5LI9 
 
 92.1 
 
 1.49987 
 
 48.92 
 
 97.1 
 
 1.53624 
 
 51.24 
 
 92.2 
 
 1.50058 
 
 48.96 
 
 97-2 
 
 1.53698 
 
 51.28 
 
 92.3 
 
 1.50130 
 
 49,01 
 
 97-3 
 
 1.53772 
 
 Si-33 
 
 92.4 
 
 1.50202 
 
 49.06 
 
 97-4 
 
 1.53846 
 
 S 1 ^ 8 
 
 92.5 
 
 1.50274 
 
 49.11 
 
 97-5 
 
 1.53920 
 
 51.42 
 
 92.6 
 
 1.50346 
 
 49.15 
 
 97.6 
 
 1-53994 
 
 51.47 
 
 92.7 
 
 1.50419 
 
 49.20 
 
 97-7 
 
 1.54068 
 
 5I-5 1 
 
 92.8 
 
 1.50491 
 
 49-25 
 
 97-8 
 
 1.54142 
 
 51.56 
 
 92.9 
 
 1-50563 
 
 49.29 
 
 97-9 
 
 1.54216 
 
 51.60 
 
TABLES 
 
 295 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 17.5\ 
 GRAVITY \ a 17.5/ 
 
 DEGREES 
 BAUME 
 
 DEGREES 
 BRIX 
 
 SPECIFIC / , 17.5\ 
 GRAVITY \ a 17.57 
 
 DEGREES 
 BAUM 
 
 98.0 
 
 1.54290 
 
 5L65 
 
 99-0 
 
 1.55040 
 
 52.11 
 
 98.1 
 
 1.54365 
 
 5I-70 
 
 99.1 
 
 i.55"5 
 
 52.15 
 
 98.2 
 
 1.54440 
 
 51-74 
 
 99.2 
 
 I.55I89 
 
 52.20 
 
 98.3 
 
 I.545I5 
 
 5 J -79 
 
 99-3 
 
 1.55264 
 
 52.24 
 
 98.4 
 
 1.54590 
 
 51-83 
 
 99-4 
 
 1.55338 
 
 52.29 
 
 98.5 
 
 1.54665 
 
 51.88 
 
 99-5 
 
 I-554I3 
 
 52.33 
 
 98.6 
 
 1.54740 
 
 51.92 
 
 99.6 
 
 1.55487 
 
 52.38 
 
 98.7 
 
 I-548I5 
 
 5 J -97 
 
 99-7 
 
 1.55562 
 
 52.42 
 
 98.8 
 
 1.54890 
 
 52.01 
 
 99.8 
 
 1-55636 
 
 52.47 
 
 98.9 
 
 I-54965 
 
 52.06 
 
 99.9 
 
 I-557II 
 
 52.51 
 
 
 
 
 100. 
 
 1.55785 
 
 52.56 
 
 2. STAMMER'S TABLE OF TEMPERATURE CORRECTIONS FOR 
 BRIX HYDROMETER READINGS 1 {For mercurial thermometer) 
 
 
 DEGREE BRIX OF THE SOLUTION 
 
 DEGREE 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 CENTI- 
 
 
 
 5 
 
 10 
 
 15 
 
 20 
 
 25 
 
 30 
 
 35 
 
 40 
 
 50 
 
 60 
 
 70 
 
 75 
 
 GRADE 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 The degree read is to be decreased by 
 
 
 
 0.17 
 
 0.30 
 
 0.41 
 
 0.52 
 
 0.62 
 
 0.72 
 
 0.82 
 
 0.92 
 
 0.98 
 
 i. ii 
 
 1.22 
 
 1.25 
 
 1.29 
 
 5 
 
 0.23 
 
 0.30 
 
 0-37 
 
 0.44 
 
 0.52 
 
 o.59 
 
 0.65 
 
 0.72 
 
 0-75 
 
 0.80 
 
 0.88 
 
 0.91 
 
 0.94 
 
 10 
 
 O.2O 
 
 0.26 
 
 0.29 
 
 o.33 
 
 0.36 
 
 0-39 
 
 0.42 
 
 o-45 
 
 0.48 
 
 0.50 
 
 0-54 
 
 0.58 
 
 0.61 
 
 ii 
 
 0.18 
 
 0.23 
 
 0.26 
 
 0.28 
 
 0.31 
 
 0-34 
 
 0.36 
 
 o.39 
 
 0.41 
 
 0.43 
 
 o-47 
 
 0.50 
 
 -53 
 
 12 
 
 0.16 
 
 0.20 
 
 0.22 
 
 0.24 
 
 0.26 
 
 0.29 
 
 0.31 
 
 0-33 
 
 0-34 
 
 0.36 
 
 0.40 
 
 0.42 
 
 0.46 
 
 13 
 
 0.14 
 
 0.18 
 
 0.19 
 
 0.21 
 
 O.22 
 
 0.24 
 
 0.26 
 
 0.27 
 
 0.28 
 
 0.29 
 
 o.33 
 
 0-35 
 
 o.39 
 
 14 
 
 0.12 
 
 0.15 
 
 0.16 
 
 O.I 7 
 
 0.18 
 
 0.19 
 
 O.2I 
 
 O.22 
 
 0.22 
 
 0.23 
 
 0.26 
 
 0.28 
 
 0.32 
 
 15 
 
 0.09 
 
 O.II 
 
 12 
 
 0.14 
 
 O.I4 
 
 0.15 
 
 0.16 
 
 0.17 
 
 0.16 
 
 0.17 
 
 0.19 
 
 0.21 
 
 0.25 
 
 16 
 
 0.06 
 
 0.07 
 
 0.08 
 
 O.09 
 
 0.10 
 
 O.IO 
 
 O.II 
 
 O.I2 
 
 O.I2 
 
 0.12 
 
 0.14 
 
 0.16 
 
 0.18 
 
 17 
 
 0.02 
 
 O.02 
 
 0.03 
 
 0.03 
 
 0.03 
 
 0.04 
 
 0.04 
 
 0.04 
 
 0.04 
 
 0.04 
 
 0.05 
 
 0.05 
 
 0.06 
 
 
 The degree read is to be increased by 
 
 18 
 
 0.02 
 
 0.03 
 
 0.03 
 
 0.03 
 
 0.03 
 
 0.03 
 
 0.03 
 
 0.03 
 
 O.O3 
 
 0.03 
 
 0.03 
 
 0.03 
 
 O.O2 
 
 19 
 
 0.06 
 
 0.08 
 
 0.08 
 
 0.09 
 
 0.09 
 
 O.IO 
 
 O.IO 
 
 O.IO 
 
 O.IO 
 
 O.IO 
 
 O.IO 
 
 0.08 
 
 0.06 
 
 20 
 
 O.II 
 
 0.14 
 
 0.15 
 
 0.17 
 
 0.17 
 
 0.18 
 
 0.18 
 
 0.18 
 
 0.19 
 
 0.19 
 
 0.18 
 
 0.15 
 
 O.II 
 
 21 
 
 O.l6 
 
 0.20 
 
 0.22 
 
 0.24 
 
 0.24 
 
 0.25 
 
 0.25 
 
 0.25 
 
 0.26 
 
 0.26 
 
 0.25 
 
 0.22 
 
 0.18 
 
 22 
 
 0.21 
 
 0.26 
 
 O.29 
 
 0.31 
 
 0.31 
 
 0.32 
 
 0.32 
 
 0.32 
 
 0.33 
 
 0.34 
 
 0.32 
 
 0.29 
 
 0.25 
 
 23 
 
 0.27 
 
 0.32 
 
 0-35 
 
 0-37 
 
 0.38 
 
 0-39 
 
 o.39 
 
 0.39 
 
 0.40 
 
 0.42 
 
 0-39 
 
 0.36 
 
 -33 
 
 2 4 
 
 0.32 
 
 0.38 
 
 0.41 
 
 0-43 
 
 0.44 
 
 0.46 
 
 0.46 
 
 0.47 
 
 0.47 
 
 0.50 
 
 0.46 
 
 0-43 
 
 0.49 
 
 25 
 
 0-37 
 
 o-44 
 
 0.47 
 
 0.49 
 
 0.51 
 
 0-53 
 
 0-54 
 
 0.55 
 
 0.55 
 
 0.58 
 
 0-54 
 
 0.51 
 
 0.48 
 
 26 
 
 0-43 
 
 0.50 
 
 o-54 
 
 0.56 
 
 0.58 
 
 0.60 
 
 0.61 
 
 0.62 
 
 0.62 
 
 0.66 
 
 0.62 
 
 0.58 
 
 o.55 
 
 27 
 
 0.49 
 
 0-57 
 
 0.61 
 
 0.63 
 
 0.65 
 
 0.68 
 
 0.68 
 
 0.69 
 
 0.70 
 
 0.74 
 
 0.70 
 
 0.65 
 
 0.62 
 
 28 
 
 0.56 
 
 0.64 
 
 0.68 
 
 0.70 
 
 0.72 
 
 0.76 
 
 0.76 
 
 0.78 
 
 0.78 
 
 0.82 
 
 0.78 
 
 0.72 
 
 0.70 
 
 2 9 
 
 0.63 
 
 0.71 
 
 0-75 
 
 0.78 
 
 0.79 
 
 0.84 
 
 0.84 
 
 0.86 
 
 0.86 
 
 0.90 
 
 0.86 
 
 0.80 
 
 0.78 
 
 30 
 
 0.70 
 
 0.78 
 
 0.82 
 
 0.87 
 
 0.87 
 
 0.92 
 
 0.92 
 
 0.94 
 
 0.94 
 
 0.98 
 
 0.94 
 
 0.88 
 
 0.86 
 
 35 
 
 1. 10 
 
 1.17 
 
 1.22 
 
 1.24 
 
 1.30 
 
 1.32 
 
 1-33 
 
 1-35 
 
 1.36 
 
 i-39 
 
 !-34 
 
 1.27 
 
 1.25 
 
 40 
 
 1.50 
 
 1.61 
 
 1.6 7 
 
 I.7I 
 
 1-73 
 
 1.79 
 
 1.79 
 
 1.80 
 
 1.82 
 
 1-83 
 
 1.78 
 
 1.69 
 
 1.65 
 
 5o 
 
 
 2.65 
 
 2. 7 I 
 
 2-74 
 
 2.78 
 
 2.80 
 
 2.80 
 
 2.80 
 
 2.80 
 
 2.79 
 
 2.70 
 
 2.56 
 
 2.51 
 
 60 
 
 
 3-87 
 
 3.88 
 
 3.88 
 
 3-88 
 
 3-88 
 
 3.88 
 
 3.88 
 
 3-90 
 
 3-82 
 
 3-70 
 
 3-43 
 
 3-4i 
 
 70 
 
 
 
 5-18 
 
 5-20 
 
 5-14 
 
 5-13 
 
 ^.10 
 
 5-08 
 
 5-o6 
 
 4.90 
 
 4.72 
 
 4-47 
 
 4-35 
 
 80 
 
 
 
 6.62 
 
 6.59 
 
 6-54 
 
 6.46 
 
 6.38 
 
 6.30 
 
 6.26 
 
 6.06 
 
 5-82 
 
 5.50 
 
 5-33 
 
 1 Note that these corrections take into consideration that the glass of the hydrometer as 
 well as the sugar solution itself is affected by the temperature change. 
 
2 9 6 
 
 TABLES 
 
 3. SCHMITZ'S TABLE FOR DETERMINING PERCENTAGE OF 
 
 BRIX READINGS 
 
 (N = 26.048 grams ; allowance being made for an increase 
 
 BRIX READING 
 
 
 BRIX READING AND 
 
 FROM 0.5 TO 12.0 
 
 SACCHARI- 
 
 
 
 
 
 
 
 
 
 
 
 METRIC 
 
 5 
 
 1.0 
 
 1 5 
 
 2.0 
 
 2.5 
 
 3.0 
 
 3.5 
 
 4 
 
 A K 
 
 Tenths of 
 a Division 
 
 Per cent 
 Sucrose 
 
 DIVISIONS 
 
 1.0019 
 
 1.0039 
 
 1.0058 
 
 1.0078 
 
 1.0098 
 
 1.0117 
 
 1.0137 
 
 1.0157 
 
 4.O 
 
 I.OI7 7 
 
 O.I 
 
 0.03 
 
 i 
 
 0.29 
 
 0.29 
 
 0.29 
 
 0.28 
 
 0.28 
 
 0.28 
 
 0.28 
 
 0.28 
 
 0.28 
 
 0.2 
 
 0.06 
 
 2 
 
 
 o-57 
 
 o-57 
 
 -57 
 
 o-57 
 
 0.56 
 
 0.56 
 
 0.56 
 
 0.56 
 
 0-3 
 
 0.08 
 
 3 
 
 
 0.85 
 
 0.85 
 
 0.85 
 
 0.85 
 
 0.85 
 
 0.85 
 
 0.84 
 
 0.84 
 
 0.4 
 
 0-5 
 
 O.I I 
 
 0.14 
 
 4 
 
 
 
 1.42 
 
 1.42 
 
 1.41 
 
 1.41 
 
 1.41 
 
 1.41 
 
 1.40 
 
 0.6 
 
 0.17 
 
 6 
 
 
 
 
 1.70 
 
 1.70 
 
 1.69 
 
 1.69 
 
 1.69 
 
 1.68 
 
 0.7 
 
 0.19 
 
 7 
 
 
 
 
 1.98 
 
 1.98 
 
 1.98 
 
 1.97 
 
 1.97 
 
 1.96 
 
 0.8 
 
 0.22 
 
 8 
 
 
 
 
 
 2.26 
 
 2.26 
 
 2.26 
 
 2.25 
 
 2.25 
 
 0.9 
 
 0.25 
 
 9 
 
 
 
 
 
 
 2-54 
 
 2-54 
 
 2-53 
 
 2-53 
 
 
 10 
 
 
 
 
 
 
 2.82 
 
 2.82 
 
 2.81 
 
 2.81 
 
 
 ii 
 
 
 
 
 
 
 
 3-10 
 
 3-09 
 
 3-09 
 
 
 12 
 13 ' 
 
 
 
 
 
 
 
 3.38 
 
 3-38 
 3-66 
 
 3-37 
 3-65 
 
 
 14 
 
 
 
 
 
 
 
 
 3-94 
 
 3-93 
 
 BRIX READING 
 
 FROM 12.5 TO 20.0 
 
 15 
 
 16 
 
 
 
 
 
 
 
 
 
 4.21 
 4-49 
 
 Tenths of 
 
 Per cent 
 
 18 
 
 
 
 
 
 
 
 
 
 
 a Division 
 
 Sucrose 
 
 19 
 
 
 
 
 
 
 
 
 
 
 
 
 20 
 
 
 
 
 
 
 
 
 
 
 O.I 
 
 0.03 
 
 21 
 
 
 
 
 
 
 
 
 
 
 O.2 
 0-3 
 
 0.05 
 0.08 
 
 22 
 23 
 
 
 
 
 
 
 
 
 
 
 0.4 
 
 O.II 
 
 24 
 
 
 
 
 
 
 
 
 
 
 0.6 
 
 0.13 
 0.16 
 
 a 
 
 
 
 
 
 
 
 
 
 
 0.7 
 
 0.19 
 
 27 
 
 
 
 
 
 
 
 
 
 
 0.8 
 
 0.21 
 
 28 
 
 
 
 
 
 
 
 
 
 
 0.9 
 
 O.24 
 
 29 
 
 
 
 
 
 
 
 
 
 
 
 30 
 
 
 
 
 
 
 
 
 
 
 
 31 
 
 
 
 
 
 
 
 
 
 
 
 32 
 
 
 
 
 
 
 
 
 
 
 
 33 
 
 
 
 
 
 
 
 
 
 
 
 34 
 
 
 
 
 
 
 
 
 
 
 
 35 
 
 
 
 
 
 
 
 
 
 
 
 36 
 
 
 
 
 
 
 
 
 
 
 
 37 
 
 
 
 
 
 
 
 
 
 
 
 38 
 
 
 
 
 
 
 
 
 
 
 
 39 
 
 
 
 
 
 
 
 
 
 
TABLES 
 
 297 
 
 SUGAR SOLUTIONS WHEN THE SACCHARIMETRIC AND 
 ARE KNOWN 
 
 of one tenth in volume in clarifying for polarizing.) 
 
 CORRESPONDING SPECIFIC GRAVITY 
 
 SACCHARI- 
 
 5.0 
 
 5.5 
 
 6.0 
 
 6.5 
 
 7.0 
 
 7.5 
 
 8.0 
 
 8.5 
 
 9.0 
 
 9.5 
 
 10.0 
 
 METRIC 
 
 1.0197 
 
 1.0217 
 
 1.0237 
 
 1.0258 
 
 1.0278 
 
 1.0298 
 
 1.0319 
 
 1-0339 
 
 1.0360 
 
 1.0381 
 
 1.0401 
 
 DIVISIONS 
 
 0.28 
 
 0.28 
 
 0.28 
 
 0.28 
 
 0.28 
 
 0.28 
 
 0.28 
 
 0.28 
 
 0.28 
 
 0.28 
 
 0.28 
 
 i 
 
 0.56 
 
 0.56 
 
 0.56 
 
 0.56 
 
 0.56 
 
 0-55 
 
 0.55 
 
 0-55 
 
 0-55 
 
 0-55 
 
 o.55 
 
 2 
 
 0.84 
 
 0.84 
 
 0.84 
 
 0.84 
 
 0.83 
 
 0.83 
 
 0.83 
 
 0.83 
 
 0.83 
 
 0.83 
 
 0.82 
 
 3 
 
 1. 12 
 
 1. 12 
 
 1. 12 
 
 i. II 
 
 I. II 
 
 i. ii 
 
 i. ii 
 
 i. ii 
 
 I.IO 
 
 I.IO 
 
 I.IO 
 
 4 
 
 I.4O 
 
 1.68 
 
 I.4O 
 
 1.68 
 
 1.40 
 1.67 
 
 1-39 
 1.67 
 
 1-39 
 
 1.67 
 
 1-39 
 1.66 
 
 It 
 
 1.38 
 1.66 
 
 1.38 
 
 1.66 
 
 1.38 
 1.65 
 
 1.37 
 1.65 
 
 6 
 
 1.96 
 
 1.96 
 
 1-95 
 
 1-95 
 
 1.95 
 
 1.94 
 
 1.94 
 
 1-93 
 
 i-93 
 
 1-93 
 
 1.92 
 
 7 
 
 2.24 
 
 2.24 
 
 2.23 
 
 2.23 
 
 2.22 
 
 2.22 
 
 2.22 
 
 2.21 
 
 2.21 
 
 2.20 
 
 2. 2O 
 
 8 
 
 2.52 
 
 2.52 
 
 2.51 
 
 2-51 
 
 2.50 
 
 2.50 
 
 2.49 
 
 2.49 
 
 2.48 
 
 2.48 
 
 2.47 
 
 9 
 
 2.80 
 
 2.80 
 
 2.79 
 
 2.79 
 
 2.78 
 
 2.78 
 
 2.77 
 
 2.76 
 
 2.76 
 
 2-75 
 
 2-75 
 
 10 
 
 3.08 
 
 3.08 
 
 3-07 
 
 3.06 
 
 3-06 
 
 3-05 
 
 3-05 
 
 3-04 
 
 3-03 
 
 3.03 
 
 3.02 
 
 ii 
 
 
 3.36 
 
 3-35 
 
 3-34 
 
 3-34 
 
 3-33 
 
 3-32 
 
 3.32 
 
 3-31 
 
 3-30 
 
 3-30 
 
 12 
 
 3.64 
 
 3-64 
 
 
 3.62 
 
 3-61 
 
 3.61 
 
 3.60 
 
 3-59 
 
 3-59 
 
 3-58 
 
 3-57 
 
 13 
 
 3-92 
 
 3-92 
 
 3-9i 
 
 3-90 
 
 3.89 
 
 3-88 
 
 3-88 
 
 3.87 
 
 3-86 
 
 3-85 
 
 3.85 
 
 14 
 
 4.20 
 
 4.19 
 
 4.19 
 
 4.18 
 
 4.17 
 
 4.16 
 
 4-15 
 
 4-15 
 
 4.14 
 
 4.13 
 
 4.12 
 
 15 
 
 4.48 
 
 4-47 
 
 447 
 
 4.46 
 
 445 
 
 4.44 
 
 443 
 
 442 
 
 4.41 
 
 4.40 
 
 4.40 
 
 10 
 
 4-77 
 
 4.76 
 
 4-75 
 
 4-74 
 
 4-73 
 
 4.72 
 
 4.71 
 
 4.70 
 
 4.69 
 
 4.68 
 
 4.67 
 
 17 
 
 
 5-03 
 
 5-02 
 
 5.01 
 
 5.00 
 
 4-99 
 
 4.99 
 
 4-97 
 
 4-97 
 
 4.96 
 
 4-95 
 
 18 
 
 
 5-32 
 
 5-31 
 
 5-29 
 
 5-28 
 
 5-27 
 
 5-26 
 
 5-25 
 
 5-24 
 
 5.23 
 
 5.22 
 
 19 
 
 
 
 5-58 
 
 5-57 
 
 5.56 
 
 5-55 
 
 5-54 
 
 5-53 
 
 5-52 
 
 5.51 
 
 5.50 
 
 20 
 
 
 
 5-86 
 
 5-85 
 
 5.84 
 
 5-83 
 
 5.82 
 
 5.81 
 
 5-79 
 
 
 5-77 
 
 21 
 
 
 
 
 6.13 
 
 6.12 
 
 
 6.09 
 
 6.08 
 
 6.07 
 
 6^06 
 
 6.05 
 
 22 
 
 
 
 
 6.41 
 
 6.40 
 
 6^38 
 
 6-37 
 
 6.36 
 
 6-35 
 
 6-33 
 
 6.32 
 
 23 
 
 
 
 
 
 6.67 
 
 6.66 
 
 6.65 
 
 6.64 
 
 6.62 
 
 6.61 
 
 6.60 
 
 24 
 
 
 
 
 
 
 6.94 
 
 6-93 
 
 6.91 
 
 6.90 
 
 6.89 
 
 6.87 
 
 2 5 
 
 
 
 
 
 
 7.22 
 
 7.20 
 
 7.19 
 
 7.17 
 
 7.16 
 
 7-15 
 
 26 
 
 
 
 
 
 
 
 7.48 
 
 7.46 
 
 745 
 
 744 
 
 742 
 
 27 
 
 
 
 
 
 
 
 7.76 
 
 7-74 
 
 7-73 
 
 7.71 
 
 7.70 
 
 28 
 
 
 
 
 
 
 
 
 8.02 
 
 8.00 
 
 7-99 
 
 7-97 
 
 29 
 
 
 
 
 
 
 
 
 
 8.28 
 
 8.26 
 
 8.25 
 
 3 
 
 
 
 
 
 
 
 
 
 8.55 
 
 8-54 
 
 8.52 
 
 
 
 
 
 
 
 
 
 
 8.83 
 
 8.81 
 
 8.80 
 
 32 
 
 
 
 
 
 
 
 
 
 
 9.09 
 
 9.07 
 
 33 
 
 
 
 
 
 
 
 
 
 
 
 9-35 
 
 34 
 
 
 
 
 
 
 
 
 
 
 
 9.62 
 
 35 
 
 
 
 
 
 
 
 
 
 
 
 
 37 
 
 
 
 
 
 
 
 
 
 
 
 
 38 
 
 
 
 
 
 
 
 
 
 
 
 
 39 
 
298 
 
 TABLES 
 
 BRIX READING 
 
 
 BRIX READING AND 
 
 FROM 0.5 TO 12.0 
 
 SACCHARI- 
 
 
 
 
 
 1 
 
 
 
 
 
 METRIC 
 
 10.5 
 
 11.0 
 
 11.5 
 
 12.0 
 
 12.5 
 
 13.0 
 
 13.5 
 
 14.0 
 
 14.5 
 
 Tenths of 
 a Division 
 
 Per cent 
 
 Sucrose 
 
 DIVISIONS 
 
 1.0422 
 
 1.0443 
 
 1.0464 
 
 1.0485 
 
 1.0506 
 
 1.0528 
 
 1.0549 
 
 1.0570 
 
 1.0592 
 
 O.I 
 
 0.03 
 
 i 
 
 0.28 
 
 0.27 
 
 0.27 
 
 0.27 
 
 0.27 
 
 0.27 
 
 0.27 
 
 0.27 
 
 0.27 
 
 0.2 
 
 0.06 
 
 2 
 
 0-55 
 
 0-55 
 
 0-55 
 
 o-55 
 
 o-54 
 
 o-54 
 
 o-54 
 
 o-54 
 
 0-54 
 
 -3 
 
 0.08 
 
 3 
 
 0.82 
 
 0.82 
 
 0.82 
 
 0.82 
 
 0.82 
 
 0.8 1 
 
 0.81 
 
 0.81 
 
 0.81 
 
 0.4 
 
 O.II 
 
 4 
 
 1. 10 
 
 1. 10 
 
 1.09 
 
 1.09 
 
 1.09 
 
 1.09 
 
 i. 08 
 
 i. 08 
 
 i. 08 
 
 -5 
 
 0.14 
 
 5 
 
 1-37 
 
 i-37 
 
 1.36 
 
 1.36 
 
 1.36 
 
 1.36 
 
 i-35 
 
 J -35 
 
 1-35 
 
 0.6 
 
 0.17 
 
 6 
 
 1.64 
 
 1.64 
 
 1.64 
 
 1.64 
 
 1.63 
 
 1.63 
 
 1.62 
 
 1.62 
 
 1.62 
 
 0.7 
 
 0.19 
 
 7 
 
 1.92 
 
 1.91 
 
 1.91 
 
 1.91 
 
 1.90 
 
 1.90 
 
 1.89 
 
 1.89 
 
 1.89 
 
 0.8 
 
 0.22 
 
 8 
 
 2.19 
 
 2.19 
 
 2.18 
 
 2.18 
 
 2.18 
 
 2.17 
 
 2.17 
 
 2.16 
 
 2.16 
 
 0.9 
 
 O.25 
 
 9 
 
 2.47 
 
 2.46 
 
 2.46 
 
 2-45 
 
 245 
 
 2.44 
 
 2.44 
 
 243 
 
 243 
 
 
 10 
 
 2.74 
 
 2.74 
 
 2-73 
 
 2.73 
 
 2.72 
 
 2.71 
 
 2.71 
 
 2.70 
 
 2.70 
 
 
 ii 
 
 3.02 
 
 3.01 
 
 3.00 
 
 3.00 
 
 2.99 
 
 2.99 
 
 2.98 
 
 2-97 
 
 2-97 
 
 
 12 
 
 3-29 
 
 3.28 
 
 3-28 
 
 3-27 
 
 3-26 
 
 3.26 
 
 3-25 
 
 3-24 
 
 3-24 
 
 
 13 
 
 3.56 
 
 3.56 
 
 3-55 
 
 3-54 
 
 3-54 
 
 3-53 
 
 3-52 
 
 3-5 1 
 
 3.51 
 
 
 14 
 
 3.84 
 
 3-83 
 
 3.82 
 
 3-82 
 
 3.81 
 
 3.80 
 
 3-79 
 
 3.78 
 
 3.78 
 
 BRIX READING 
 
 15 
 
 16 
 
 4.11 
 4-39 
 
 4.11 
 4.38 
 
 4.10 
 4-37 
 
 4.09 
 4-3 
 
 4.08 
 4-35 
 
 4.07 
 4-34 
 
 4.06 
 4-33 
 
 4.06 
 4-33 
 
 4-05 
 4-32 
 
 FROM 12.5 TO 20.0 
 
 i? 
 
 4.66 
 
 4.65 4.64 
 
 4- 6 3 
 
 4.62 
 
 4.62 
 
 4.61 
 
 4.60 
 
 
 Tenths of 
 a Division 
 
 Per cent 
 Sucrose 
 
 18 
 19 
 
 4-93 
 5-21 
 
 4-93 
 
 5-20 
 
 4.91 
 5-19 
 
 4.91 
 5-i8 
 
 4.90 
 5-17 
 
 4.89 
 5.16 
 
 4.88 
 5-15 
 
 4.87 
 5-14 
 
 5.13 
 
 
 
 20 
 
 549 
 
 5-47 
 
 546 
 
 545 
 
 5-44 
 
 543 
 
 542 
 
 54i 
 
 540 
 
 O.I 
 
 0.03 
 
 21 
 
 5.76 
 
 5-75 
 
 5-74 
 
 5-73 
 
 5-71 
 
 5-70 
 
 5.69 
 
 5.68 
 
 5.67 
 
 O.2 
 
 0.05 
 
 22 
 
 6.03 
 
 6.02 
 
 6.01 
 
 6.00 
 
 5-99 
 
 5-97 
 
 5-90 
 
 5-95 
 
 5-94 
 
 -3 
 
 0.08 
 
 2 3 
 
 6.31 
 
 6.30 
 
 6.28 
 
 6.27 
 
 6.26 
 
 6.24 
 
 6.23 
 
 6.22 
 
 6.21 
 
 0.4 
 
 O.II 
 
 24 
 
 6.58 
 
 6.57 
 
 6.56 
 
 6-54 
 
 6-53 
 
 6.52 
 
 6.50 
 
 6.49 
 
 6.48 
 
 0.5 
 
 0.13 
 
 25 
 
 6.86 
 
 6.84 
 
 6.83 
 
 6.82 
 
 6.80 
 
 6.79 
 
 6.78 
 
 6.76 
 
 6-75 
 
 0.6 
 
 0.16 
 
 26 
 
 7-13 
 
 7.12 
 
 7.10 
 
 7.09 
 
 7.07 
 
 7.06 
 
 7.05 
 
 7-03 
 
 7.02 
 
 0.7 
 
 0.19 
 
 27 
 
 7.41 
 
 7-39 
 
 7.38 
 
 7.36 
 
 7-35 
 
 7-33 
 
 7-32 
 
 7-30 
 
 7.29 
 
 0.8 
 
 0.21 
 
 28 
 
 7.68 
 
 7.66 
 
 7.65 
 
 7-63 
 
 7.62 
 
 7.60 
 
 7-59 
 
 7-57 
 
 7-56 
 
 0.9 
 
 0.24 
 
 2 9 
 
 7.96 
 
 7-94 
 
 7.92 
 
 7.91 
 
 7.89 
 
 7.87 
 
 7.86 
 
 7.84 
 
 7.83 
 
 
 3 
 
 8.23 
 
 8.21 
 
 8.20 
 
 8.18 
 
 8.16 
 
 8.15 
 
 8.13 
 
 8.ii 
 
 8.10 
 
 
 31 
 
 8.50 
 
 8.49 
 
 8.47 
 
 8.45 
 
 8.44 
 
 8.42 
 
 8.40 
 
 8-39 
 
 8-37 
 
 
 32 
 
 8.78 
 
 8.76 
 
 8.74 
 
 8.73 
 
 8.71 
 
 8.69 
 
 8.67 
 
 8.66 
 
 8.64 
 
 
 33 
 
 9.05 
 
 9-03 
 
 9.02 
 
 9.00 
 
 8.98 
 
 8.96 
 
 8.94 
 
 8-93 
 
 8.91 
 
 
 34 
 
 9-33 
 
 9.3i 
 
 9.29 
 
 9.27 
 
 9-25 
 
 9-23 
 
 9.22 
 
 9.20 
 
 9.18 
 
 
 35 
 
 9.60 
 
 9.58 
 
 9.56 
 
 9-54 
 
 9-53 
 
 9-51 
 
 949 
 
 947 
 
 945 
 
 
 36 
 
 9.88 
 
 9.86 
 
 9.84 
 
 982 
 
 9.80 
 
 978 
 
 9.76 
 
 9-74 
 
 9.72 
 
 
 37 
 
 10.15 
 
 10.13 
 
 10. 1 1 
 
 10.09 
 
 10.07 
 
 10.05 
 
 10.03 
 
 IO.OI 
 
 9.99 
 
 
 38 
 
 
 10.40 
 
 10.38 
 
 10.36 
 
 10.34 
 
 10.32 
 
 10.30 
 
 10.28 
 
 10.26 
 
 
 39 
 
 
 10.68 
 
 10.66 
 
 10.64 
 
 10.61 
 
 10.59 
 
 10.57 
 
 iQ-55 
 
 10.53 
 
TABLES 
 
 299 
 
 CORRESPONDING SPECIFIC GRAVITY 
 
 
 15.0 
 
 15.5 
 
 16.0 
 
 16.5 
 
 17.0 
 
 17.5 
 
 18.0 
 
 18.5 
 
 19.0 
 
 19.5 
 
 20.0 
 
 SACCHARI- 
 
 METRIC 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1.0613 
 
 1.0635 
 
 1.0657 
 
 1.0678 
 
 1.0700 
 
 1.0722 
 
 1.0744 
 
 1.0766 
 
 1.0788 
 
 1.081 1 
 
 1.0833 
 
 
 0.27 
 
 0.27 
 
 0.27 
 
 0.27 
 
 0.27 
 
 0.27 
 
 0.27 
 
 0.27 
 
 0.27 
 
 0.27 
 
 0.26 
 
 I 
 
 0.54 
 0.81 
 
 0-54 
 0.81 
 
 0-54 
 0.80 
 
 o-54 
 0.80 
 
 0-53 
 0.80 
 
 o-53 
 0.80 
 
 0-53 
 0.80 
 
 o-53 
 0.80 
 
 0.79 
 
 o-53 
 0.79 
 
 0-53 
 0.79 
 
 2 
 
 3 
 
 1. 08 
 
 i. 08 
 
 1.07 
 
 1.07 
 
 1.07 
 
 1.07 
 
 i. 06 
 
 i. 06 
 
 1. 06 
 
 1.06 
 
 1. 06 
 
 4 
 
 I -35 
 
 1-34 
 
 1-34 
 
 !. 34 
 
 !. 34 
 
 i-33 
 
 i-33 
 
 1-33 
 
 1.32 
 
 1.32 
 
 1.32 
 
 5 
 
 1^62 
 
 1.61 
 
 1.61 
 
 1.61 
 
 1. 60 
 
 i. 60 
 
 1.60 
 
 i-59 
 
 
 i-59 
 
 1.58 
 
 6 
 
 1.88 
 
 1.88 
 
 1.88 
 
 1.87 
 
 1.87 
 
 1.86 
 
 1.86 
 
 1.86 
 
 1.1s 
 
 1.85 
 
 1.85 
 
 7 
 
 2.15 
 
 2.15 
 
 2.15 
 
 2.14 
 
 2.14 
 
 2.13 
 
 2.13 
 
 2.12 
 
 2.12 
 
 2.12 
 
 2. II 
 
 8 
 
 2.42 
 
 2.42 
 
 2.41 
 
 2.41 
 
 2.40 
 
 2.40 
 
 2-39 
 
 2-39 
 
 2.38 
 
 2. 3 8 
 
 2-37 
 
 9 
 
 2.69 
 
 2.69 
 
 2.68 
 
 2.68 
 
 2.67 
 
 2.67 
 
 2.66 
 
 2.65 
 
 2.65 
 
 2.64 
 
 2.64 
 
 10 
 
 2.96 
 
 2-95 
 
 2-95 
 
 2.94 
 
 2.94 
 
 2.93 
 
 2.92 
 
 2.92 
 
 2.91 
 
 2.91 
 
 2.90 
 
 ii 
 
 3-23 
 
 3.22 
 
 3.22 3.21 
 
 3.20 
 
 3.20 
 
 3-19 
 
 3.18 
 
 3-18 
 
 3-17 
 
 3-17 
 
 12 
 
 3-50 
 
 3-49 
 
 3-49 
 
 348 
 
 3-47 
 
 346 
 
 
 3-45 
 
 3-44 
 
 3-44 
 
 3-43 
 
 13 
 
 3-77 
 
 
 3-75 
 
 3-75 
 
 3-74 
 
 3-73 
 
 3-72 
 
 3-72 
 
 
 3-70 
 
 3-69 
 
 
 4.04 
 
 4.03 
 
 4.02 
 
 4.02 
 
 4.01 
 
 4.00 
 
 3-99 
 
 3.98 
 
 3-97 
 
 3-97 
 
 3.96 
 
 15 
 
 
 4-30 
 
 4.29 
 
 4.28 
 
 4.27 
 
 4.26 
 
 4.26 
 
 4-25 
 
 4.24 
 
 4-23 
 
 4.22 
 
 16 
 
 4.58 
 
 4-57 
 
 4-56 
 
 4-55 
 
 4-54 
 
 4-53 
 
 4-52 
 
 4-51 
 
 4-50 
 
 4.49 
 
 4.48 
 
 17 
 
 4-85 
 
 4.84 
 
 4-83 
 
 4.82 
 
 4.81 
 
 4.80 
 
 4-79 
 
 4.78 
 
 4-77 
 
 4.76 
 
 4-75 
 
 18 
 
 5.12 
 
 5-II 
 
 5.10 
 
 5.09 
 
 5.08 
 
 5.06 
 
 5-05 
 
 5-04 
 
 5-03 
 
 5.02 
 
 5.01 
 
 19 
 
 5-39 
 
 5.38 
 
 5.36 
 
 5-35 
 
 5-34 
 
 5-33 
 
 5-32 
 
 53i 
 
 5-30 
 
 5-29 
 
 5.28 
 
 20 
 
 5-66 
 
 5.65 
 
 5.63 
 
 5.62 
 
 5.61 
 
 5.60 
 
 5-59 
 
 5*58 
 
 5.56 
 
 5-55 
 
 5-54 
 
 21 
 
 5-93 
 
 
 5-9 
 
 
 5.88 
 
 5-87 
 
 5-85 
 
 5-84 
 
 5-83 
 
 5-82 
 
 5.80 
 
 22 
 
 6. 20 
 
 6!i8 
 
 6.17 
 
 6.16 
 
 6.14 
 
 6.13 
 
 6.12 
 
 
 6.09 
 
 6.08 
 
 6.07 
 
 2 3 
 
 6.46 
 
 6-45 
 
 6.44 
 
 6-43 
 
 6.41 
 
 6.40 
 
 6-39 
 
 6-37 
 
 6.36 
 
 6-35 
 
 6-33 
 
 2 4 
 
 6-73 
 
 6.72 
 
 6.71 
 
 6.69 
 
 6.68 
 
 6.67 
 
 6.65 
 
 6.64 
 
 6.63 
 
 6.61 
 
 6.60 
 
 25 
 
 7.00 
 
 6.99 
 
 6.97 
 
 6.96 
 
 6-95 
 
 6-93 
 
 6.92 
 
 6.90 
 
 6.89 
 
 6.88 
 
 6.86 
 
 26 
 
 7.27 
 
 7.26 
 
 7.24 
 
 7-23 
 
 7.21 
 
 7.20 
 
 7.18 
 
 7.17 
 
 7.15 
 
 7.14 
 
 7-13 
 
 27 
 
 7-54 
 
 7-53 
 
 7.51 
 
 7-50 
 
 7.48 
 
 7-47 
 
 7-45 
 
 7-44 
 
 7.42 
 
 7.40 
 
 7-39 
 
 28 
 
 7.81 
 
 7.80 
 
 7.78 
 
 7-77 
 
 7-75 
 
 7-73 
 
 7.72 
 
 7.70 
 
 7.68 
 
 7.67 
 
 7.65 
 
 2 9 
 
 8.08 
 
 8.06 
 
 8.05 
 
 8.03 
 
 8.02 
 
 8.00 
 
 7.98 
 
 7-97 
 
 7-95 
 
 7-93 
 
 7.92 
 
 30 
 
 8-35 
 
 8-33 
 
 8.32 
 
 8.30 
 
 8.28 
 
 8.27 
 
 8.25 
 
 8.23 
 
 8.21 
 
 8.20 
 
 8.18 
 
 3 l 
 
 8.62 
 
 8.60 
 
 8.58 
 
 8-57 
 
 8-55 
 
 8-53 
 
 8.51 
 
 8.50 
 
 8.48 
 
 8.46 
 
 8-45 
 
 3 2 
 
 8.89 
 
 8.87 
 
 8.85 
 
 8.84 
 
 8.82 
 
 8.80 
 
 8.78 
 
 8.76 
 
 8-75 
 
 8-73 
 
 8.71 
 
 33 
 
 9.16 
 
 9.14 
 
 9.12 
 
 9.10 
 
 9.09 
 
 9.07 
 
 9-5 
 
 9-03 
 
 9.01 
 
 8.99 
 
 8.97 
 
 34 
 
 9-43 
 
 9.41 
 
 9-39 
 
 9-37 
 
 9-35 
 
 9-34 
 
 9.3i 
 
 9-3 
 
 9.28 
 
 9.26 
 
 9.24 
 
 35 
 
 9.70 
 
 9.68 
 
 9.66 
 
 9.64 
 
 9.62 
 
 9.60 
 
 9*58 
 
 
 9-54 
 
 9-52 
 
 9-5 
 
 36 
 
 9-97 
 
 9-95 
 
 9-93 
 
 9.91 
 
 9.89 
 
 9.87 
 
 9-85 
 
 9.83 
 
 9.81 
 
 9-79 
 
 9-77 
 
 37 
 
 10.24 
 
 10.22 
 
 10.20 
 
 10.18 
 
 10.15 
 
 10.13 
 
 IO.II 
 
 10.09 
 
 10.07 
 
 10.05 
 
 10.03 
 
 38 
 
 10.51 
 
 10.49 
 
 10.46 
 
 10.44 
 
 10.42 
 
 10.40 
 
 10.38 
 
 10.36 
 
 10.34 
 
 10.32 
 
 10.29 
 
 39 
 
300 
 
 TABLES 
 
 BRIX READING 
 
 
 BRIX READING AND 
 
 FROM II.5 TO 22.5 
 
 METRIC 
 
 1 1 
 
 1 . > n 
 
 
 1 ? A 
 
 1 O E 
 
 
 Tenths of 
 a Division 
 
 Per cent 
 Sucrose 
 
 DIVISIONS 
 
 1 l.O 
 
 1.0464 
 
 1Z.U 
 
 1.0485 
 
 1.0506 
 
 lo.U 
 
 1.0528 
 
 lo.O 
 
 1.0549 
 
 1.0570 
 
 
 
 40 
 
 10.93 
 
 10.91 
 
 10.89 
 
 10.86 
 
 10.84 
 
 10.82 
 
 O.I 
 
 0.03 
 
 4 1 
 
 
 II.I8 
 
 ii. 16 
 
 11.14 
 
 II. 12 
 
 11.09 
 
 0.2 
 
 0.05 
 
 42 
 
 
 11.46 
 
 n-43 
 
 11.41 
 
 H-39 
 
 11.36 
 
 0-3 
 
 0.08 
 
 43 
 
 
 
 11.71 
 
 11.68 
 
 u.66 
 
 11.64 
 
 0.4 
 
 O.II 
 
 44 
 
 
 
 11.98 
 
 11 -95 
 
 H-93 
 
 11.91 
 
 o-5 
 0.6 
 
 0.13 
 0.16 
 
 45 
 47 
 
 
 
 12.25 
 
 12.23 
 12.50 
 
 12. 2O 
 12.47 
 
 I2.I8 
 12.45 
 
 0.2 
 
 0.19 
 
 46 
 
 
 
 
 
 12.74 
 
 12.72 
 
 0.8 
 
 0.21 
 
 48 
 
 
 
 
 
 I3.O2 
 
 12.99 
 
 0.9 
 
 0.24 
 
 49 
 
 
 
 
 
 
 13.26 
 
 
 50 
 
 
 
 
 
 
 
 
 52 
 
 
 
 
 
 
 
 
 53 
 
 
 
 
 
 
 
 
 54 
 
 
 
 
 
 
 
 BRIX READING 
 
 55 
 56 
 
 
 
 
 
 
 
 FROM 23.0 TO 24.0 
 
 
 
 
 
 
 
 
 Tenths of 
 a Division 
 
 Per cent 
 Sucrose 
 
 58 
 59 
 
 
 
 
 
 
 
 
 
 60 
 
 
 
 
 
 
 
 O.I 
 
 0.03 
 
 61 
 
 
 
 
 
 
 
 0.2 
 
 0.05 
 
 62 
 
 
 
 
 
 
 
 o-3 
 
 O.o8 
 
 63 
 
 
 
 
 
 
 
 0.4 
 
 O.IO 
 
 64 
 
 
 
 
 
 
 
 0.5 
 
 0.13 
 
 65 
 
 
 
 
 
 
 
 0.6 
 
 0.16 
 
 66 
 
 
 
 
 
 
 
 0.7 
 
 0.18 
 
 67 
 
 
 
 
 
 
 
 0.8 
 
 0.21 
 
 68 
 
 
 
 
 
 
 
 0.9 
 
 0.23 
 
 69 
 
 
 
 
 
 
 
 
 70 
 
 
 
 
 
 
 
 
 72 
 
 
 
 
 
 
 
 
 73 
 
 
 
 
 
 
 
 
 74 
 
 
 
 
 
 
 
 
 P 
 
 
 
 
 
 
 
 
 77 
 
 
 
 
 
 
 
 
 78 
 
 
 
 
 
 
 
TABLES 
 
 301 
 
 CORRESPONDING SPECIFIC GRAVITY 
 
 
 14.5 
 
 15.0 
 
 15.5 
 
 16.0 
 
 16.5 
 
 17.0 
 
 17.5 
 
 SACCHARI- 
 
 METRIC 
 
 1.0592 
 
 1.0613 
 
 1.0635 
 
 1.0657 
 
 1.0678 
 
 1.0700 
 
 1.0722 
 
 DIVISIONS 
 
 10.80 
 
 10.78 
 
 10.76 
 
 10.73 
 
 10.71 
 
 10.69 
 
 10.67 
 
 40 
 
 11.07 
 
 11-05 
 
 11.03 
 
 11.00 
 
 10.98 
 
 10.96 
 
 10.94 
 
 41 
 
 n-34 
 
 11.32 
 
 11.29 
 
 11.27 
 
 11.25 
 
 11.23 
 
 ii. 20 
 
 42 
 
 II.OI 
 
 11-59 
 
 11.56 
 
 n-54 
 
 11.52 
 
 11.49 
 
 11.47 
 
 43 
 
 11.88 
 
 u.86 
 
 11.83 
 
 11.81 
 
 11.79 
 
 11.76 
 
 11.74 
 
 44 
 
 12.15 
 
 12.13 
 
 12.10 
 
 12.08 
 
 12.05 
 
 12.03 
 
 12.01 
 
 45 
 
 12.42 
 
 12.40 
 
 12.37 
 
 12.35 
 
 12.32 
 
 12.30 
 
 12.27 
 
 46 
 
 12.69 
 
 12.67 
 
 12.64 
 
 12. 6l 
 
 12.59 
 
 12.56 
 
 I2.5 4 
 
 47 
 
 12.97 
 
 12.94 
 
 12.91 
 
 12.88 
 
 12.86 
 
 12.83 
 
 I2.8I 
 
 48 
 
 13-23 
 
 13.21 
 
 13.18 
 
 13.15 
 
 13.13 
 
 13.10 
 
 13.07 
 
 49 
 
 I3-50 
 I3-78 
 
 13.48 
 J3-75 
 
 13-45 
 13.72 
 
 13-42 
 13.69 
 
 13.40 
 13.66 
 
 13-37 
 13.64 
 
 13-34 
 I3.6I 
 
 50 
 5i 
 
 
 14.02 
 
 *3-99 
 
 13.96 
 
 13-93 
 
 13.90 
 
 13.88 
 
 52 
 
 
 14.29 
 
 14.26 
 
 14-23 
 
 14.20 
 
 14.17 
 
 14.14 
 
 53 
 
 
 
 14.53 
 
 14.50 
 
 14.47 
 
 14.44 
 
 14.41 
 
 54 
 
 
 
 14.80 
 
 14-77 
 
 14.74 
 
 14.71 
 
 14.68 
 
 55 
 
 
 
 
 15-03 
 
 15.00 
 
 14.97 
 
 14.94 
 
 56 
 
 
 
 
 15-30 
 
 15-27 
 
 15.24 
 
 15.21 
 
 57 
 
 
 
 
 15-57 
 
 15-54 
 
 15-51 
 
 I5. 4 8 
 
 58 
 
 
 
 
 
 15.81 
 
 I5-78 
 
 15-75 
 
 59 
 
 
 
 
 
 
 16 05 
 
 16.01 
 
 60 
 
 
 
 
 
 
 16.31 
 
 16.28 
 
 61 
 
 
 
 
 
 
 
 16-55 
 
 62 
 
 
 
 
 
 
 
 16.82 
 
 63 
 
 
 
 
 
 
 
 
 64 
 
 
 
 
 
 
 
 
 65 
 
 
 
 
 
 
 
 
 66 
 
 
 
 
 
 
 
 
 67 
 
 
 
 
 
 
 
 
 68 
 
 
 
 
 
 
 
 
 69 
 
 
 
 
 
 
 
 
 70 
 
 
 
 
 
 
 
 
 71 
 
 
 
 
 
 
 
 
 72 
 
 
 
 
 
 
 
 
 73 
 
 
 
 
 
 
 
 
 74 
 
 
 
 
 
 
 
 
 75 
 
 
 
 
 
 
 
 
 76 
 
 
 
 
 
 
 
 
 77 
 
 
 
 
 
 
 
 
 78 
 
 
 
 
 
 
 
 
 79 
 
 
 
 
 
 
 
 
 80 
 
302 
 
 TABLES 
 
 BRIX READING 
 
 
 BRIX READING AND 
 
 FROM 11.5 TO 22.5 
 
 SACCHARI- 
 
 
 
 
 
 
 
 
 Tenths of 
 
 Per cent 
 
 METRIC 
 
 DIVISIONS 
 
 18.0 
 
 18.5 
 
 19.0 
 
 19.5 
 
 20.0 
 
 20.5 
 
 a Division 
 
 Sucrose 
 
 
 1.0744 
 
 1.0766 
 
 1.0788 
 
 1.0811 
 
 1.0833 
 
 1.0855 
 
 
 
 40 
 
 10.64 
 
 10.62 
 
 10. 60 
 
 10.58 
 
 10.56 
 
 10.54 
 
 O.I 
 
 0.03 
 
 41 
 
 10.91 
 
 10.89 
 
 10.87 
 
 10.85 
 
 10.82 
 
 10.80 
 
 0.2 
 
 0.05 
 
 42 
 
 ii. iB 
 
 ii. 16 
 
 11.13 
 
 II. II 
 
 11.09 
 
 11.07 
 
 0.4 
 
 0.08 
 
 O.II 
 
 43 
 44 
 
 H.45 
 11.71 
 
 11.42 
 11.69 
 
 11.40 
 
 11.66 
 
 11.38 
 11.64 
 
 11-35 
 11.62 
 
 "59 
 
 0-5 
 
 0.13 
 
 45 
 
 11.98 
 
 11.96 
 
 "93 
 
 11.91 
 
 11.88 
 
 11.86 
 
 0.6 
 
 0.16 
 
 46 
 
 12.25 
 
 12.22 
 
 12.20 
 
 12.17 
 
 12.15 
 
 12.12 
 
 -7 
 
 0.19 
 
 47 
 
 12.51 
 
 12.49 
 
 12.46 
 
 12.44 
 
 12.41 
 
 12.39 
 
 0.8 
 
 21 
 
 48 
 
 12.78 
 
 12.75 
 
 12.73 
 
 12.70 
 
 12.67 
 
 12.65 
 
 0.9 
 
 0.24 
 
 49 
 
 13-05 
 
 13.02 
 
 12.99 
 
 12.97 
 
 12.94 
 
 12.91 
 
 
 50 
 
 13.31 
 
 13.29 
 
 13.26 
 
 13-23 
 
 13.20 
 
 13.18 
 
 
 51 
 
 I3-58 
 
 13-55 
 
 I3.52 
 
 I3-50 
 
 1347 
 
 13.44 
 
 
 52 
 
 13.85 
 
 13.82 
 
 13.79 
 
 13.76 
 
 13.73 
 
 13.70 
 
 
 53 
 
 14.11 
 
 14.08 
 
 14.05 
 
 14.03 
 
 14.00 
 
 13.97 
 
 
 54 
 
 14.38 
 
 14.35 
 
 I4.32 
 
 14.29 
 
 14.26 
 
 14.23 
 
 BRIX READING 
 
 FROM 23.0 TO 24.0 
 
 55 
 56 
 
 14.65 
 14.91 
 
 14.62 
 14.88 
 
 14.59 
 14.85 
 
 14.56 
 14.82 
 
 14-53 
 14.79 
 
 14.50 
 14.76 
 
 
 
 57 
 
 15.18 
 
 I5'I5 
 
 15.12 
 
 15.09 
 
 15.06 
 
 15.02 
 
 Tenths of 
 
 Per cent 
 
 58 
 
 15-45 
 
 15.42 
 
 15.38 
 
 15-35 
 
 15-32 
 
 I5-29 
 
 a Division 
 
 Sucrose 
 
 59 
 
 
 15.68 
 
 15.65 
 
 15.62 
 
 15.58 
 
 15-55 
 
 
 
 60 
 
 15.98 
 
 15.95 
 
 15.92 
 
 15.88 
 
 I5-85 
 
 15.82 
 
 O.I 
 
 0.03 
 
 61 
 
 16.25 
 
 16.21 
 
 16.18 
 
 16.15 
 
 16.11 
 
 16.08 
 
 0.2 
 
 0.05 
 
 62 
 
 16.52 
 
 16.48 
 
 16.45 
 
 16.41 
 
 16.38 
 
 16.35 
 
 0.3 
 
 0.08 
 
 63 
 
 16.78 
 
 16.75 
 
 16.71 
 
 16.68 
 
 16.64 
 
 16.61 
 
 0.4 
 
 0.10 
 
 64 
 
 17.05 
 
 17.01 
 
 16.98 
 
 16.94 
 
 16.91 
 
 16.87 
 
 0.5 
 
 0.6 
 
 0.13 
 0.16 
 
 
 
 17.32 
 
 17.28 
 
 17.55 
 
 17.24 
 
 17.21 
 J 7-47 
 
 17.17 
 
 17.44 
 
 17.14 
 17.40 
 
 0.7 
 
 0.18 
 
 67 
 
 
 17.81 
 
 17.78 
 
 17.74 
 
 17.70 
 
 17.67 
 
 0.8 
 
 O.2I 
 
 68 
 
 
 
 18.04 
 
 18.00 
 
 17.97 
 
 17.93 
 
 0.9 
 
 o 23 
 
 69 
 
 
 
 18.31 
 
 18.27 
 
 18.23 
 
 18.19 
 
 
 70 
 
 
 
 
 18.53 
 
 18.50 
 
 18.46 
 
 
 
 
 
 
 
 18.76 
 
 18.72 
 
 
 72 
 
 
 
 
 
 19.03 
 
 18.99 
 
 
 73 
 
 
 
 
 
 
 19.25 
 
 
 74 
 
 
 
 
 
 
 19.52 
 
 
 75 
 
 
 
 
 
 
 
 19.78 
 
 
 76 
 
 
 
 
 
 
 
 
 77 
 
 
 
 
 
 
 
 
 78 
 
 
 
 
 
 
 
 
 79 
 
 
 
 
 
 
 
 
 80 
 
 
 
 
 
 
 
TABLES 
 
 303 
 
 CORRESPONDING SPECIFIC GRAVITY 
 
 
 21.0 
 
 21.5 
 
 22.0 
 
 22.5 
 
 23.0 
 
 23.5 
 
 24.0 
 
 SACCHARI- 
 
 METRIC 
 
 
 
 
 
 
 
 
 DIVISIONS 
 
 1.0878 
 
 i.ogoo 
 
 1.0923 
 
 1.0946 
 
 1.0969 
 
 1.0992 
 
 1.1015 
 
 
 10.52 
 
 10.49 
 
 10.47 
 
 10.45 
 
 10.43 
 
 10.41 
 
 10.38 
 
 40 
 
 10.78 
 
 10.76 
 
 10.74 
 
 10.71 
 
 10.69 
 
 10.67 
 
 10.65 
 
 41 
 
 11.04 
 
 11.02 
 
 11.00 
 
 10.97 
 
 10.95 
 
 10.93 
 
 10.90 
 
 42 
 
 H.3I 
 
 11.28 
 
 11.26 
 
 11.24 
 
 II. 21 
 
 11.19 
 
 11.17 
 
 43 
 
 11-57 
 
 n-55 
 
 11.52 
 
 11.50 
 
 11.47 
 
 H.45 
 
 11.42 
 
 44 
 
 11.83 
 
 ii. 81 
 
 11.78 
 
 11.76 
 
 H-73 
 
 11.71 
 
 11.69 
 
 45 
 
 12.09 
 
 12.07 
 
 12.05 
 
 12.02 
 
 12.00 
 
 11.97 
 
 11.94 
 
 46 
 
 12.36 
 
 12.33 
 
 12.31 
 
 12.28 
 
 12.26 
 
 12.23 
 
 12.21 
 
 47 
 
 12.62 
 
 12.60 
 
 12.57 
 
 12.54 
 
 12.52 
 
 12.49 
 
 12.47 
 
 48 
 
 12.88 
 
 12.86 
 
 12.83 
 
 I2.8I 
 
 12.78 
 
 12-75 
 
 12.73 
 
 49 
 
 13.15 
 
 13.12 
 
 13.09 
 
 13.07 
 
 13.04 
 
 13.01 
 
 12.99 
 
 50 
 
 1341 
 
 13-39 
 
 I3-36 
 
 13-33 
 
 I3-30 
 
 13.27 
 
 I3-25 
 
 5i 
 
 13.68 
 
 13-65 
 
 13.62 
 
 13-59 
 
 I3-56 | 13-53 
 
 I3-5I 
 
 52 
 
 13-94 
 
 ^Q 1 
 
 13.88 
 
 I3-85 
 
 13.82 
 
 13-79 
 
 13-77 
 
 53 
 
 14.20 
 
 14.17 
 
 14.14 
 
 14.11 
 
 14.08 
 
 14.06 
 
 14.02 
 
 54 
 
 14.47 
 
 14.44 
 
 14.41 
 
 14.38 
 
 14-35 
 
 14.32 
 
 14.29 
 
 55 
 
 14.73 
 
 14.70 
 
 14.67 
 
 14.64 
 
 I4.6I 
 
 14.58 
 
 z 4-55 
 
 56 
 
 14.99 
 
 14.96 
 
 J 4-93 
 
 14.90 
 
 I4.8 7 
 
 14.84 
 
 14.81 
 
 57 
 
 15.26 
 
 15.23 
 
 I5-I9 
 
 I5.I6 
 
 15.13 
 
 15.10 
 
 15-07 
 
 58 
 
 15.52 
 
 15-49 
 
 15.46 
 
 1542 
 
 15-39 
 
 I5-36 
 
 15-33 
 
 59 
 
 I5.78 
 
 15-75 
 
 I5-72 
 
 15.69 
 
 I5.65 
 
 15.62 
 
 15.59 
 
 60 
 
 16.05 
 
 16.01 
 
 15.98 
 
 15-95 
 
 J5-9 1 
 
 15.88 
 
 15-85 
 
 61 
 
 16.31 
 
 16.28 
 
 16.24 
 
 16.21 
 
 16.18 
 
 16.14 
 
 16.11 
 
 62 
 
 \657 
 
 16.54 
 
 16.51 
 
 16.47 
 
 16.44 
 
 16.40 
 
 16.37 
 
 63 
 
 16.84 
 
 16.80 
 
 16.77 
 
 16.73 
 
 16.70 
 
 16.66 
 
 16.63 
 
 64 
 
 17.10 
 
 17.07 
 
 17.03 
 
 17.00 
 
 16.96 
 
 16.92 
 
 16.89 
 
 65 
 
 17-37 
 
 17-33 
 
 17.29 
 
 17.26 
 
 17.22 
 
 17.19 
 
 I7-I5 
 
 66 
 
 17.63 
 
 17.59 
 
 17.56 
 
 17.52 
 
 17.48 
 
 17-45 
 
 17.41 
 
 67 
 
 17.89 
 
 17.86 
 
 17.82 
 
 17.78 
 
 17-74 
 
 17.71 
 
 17.67 
 
 68 
 
 18.16 
 
 18.12 
 
 18.08 
 
 18.04 
 
 18.00 
 
 17.97 
 
 17.93 
 
 69 
 
 18.42 
 
 18.38 
 
 18-35 
 
 18.31 
 
 18.27 
 
 18.23 
 
 18.19 
 
 70 
 
 18.68 
 
 18.65 
 
 18.61 
 
 18.57. 
 
 18.53 
 
 18.49 
 
 18.45 
 
 71 
 
 18.95 
 
 18.91 
 
 18.87 
 
 18.83 
 
 18.79 
 
 18.75 
 
 18.71 
 
 72 
 
 19.21 
 
 19.17 
 
 19-13 
 
 19.09 
 
 19.05 
 
 19.01 
 
 18.97 
 
 73 
 
 19.48 
 
 19.44 
 
 19.40 
 
 19-35 
 
 19-31 
 
 19.27 
 
 19.23 
 
 74 
 
 19.74 
 
 19.70 
 
 19.66 
 
 19.62 
 
 19-57 
 
 19-53 
 
 19.49 
 
 75 
 
 20.00 
 
 19.96 
 
 19.92 
 
 19.88 
 
 19.84 
 
 19.80 
 
 19-75 
 
 76 
 
 20.27 
 
 20.22 
 
 20.18 
 
 20.14 
 
 20.10 
 
 20.06 
 
 20.01 
 
 77 
 
 
 20.49 
 
 20.45 
 
 20.40 
 
 20.36 
 
 20.32 
 
 20.27 
 
 78 
 
 
 20-75 
 
 20.71 
 
 20.66 
 
 20.62 
 
 20.58 
 
 20.54 
 
 79 
 
 
 
 20.97 
 
 20.93 
 
 20.88 
 
 20.84 
 
 20.80 
 
 80 
 
304 
 
 TABLES 
 
 4. EQUIVALENTS OF DEXTROSE, MALTOSE, AND LACTOSE 
 IN PARTS OF COPPER OXIDE OBTAINED BY DEFREN'S 
 METHOD OF DETERMINATION 
 
 PARTS COPPER 
 OXIDE 
 
 PARTS 
 DEXTROSE 
 
 PARTS 
 MALTOSE 
 
 PARTS 
 LACTOSE 
 
 PARTS COPPER 
 OXIDE 
 
 PARTS 
 DEXTROSE 
 
 PARTS 
 MALTOSE 
 
 PARTS 
 LACTOSE 
 
 30 
 
 13.2 
 
 21.7 
 
 18.8 
 
 77 
 
 34-0 
 
 56.0 
 
 48.5 
 
 31 
 
 13.7 
 
 22.4 
 
 19-5 
 
 78 
 
 344 
 
 56.7 
 
 49.2 
 
 32 
 
 14.1 
 
 23.1 
 
 20.1 
 
 79 
 
 34-9 
 
 574 
 
 49.8 
 
 33 
 
 14.6 
 
 23-9 
 
 20.7 
 
 80 
 
 354 
 
 58.1 
 
 50.5 
 
 34 
 
 15-0 
 
 24.6 
 
 21.4 
 
 81 
 
 35-9 
 
 58.9 
 
 
 35 
 
 154 
 
 25.3 
 
 22.0 
 
 82 
 
 36'3 
 
 59-6 
 
 5 J 7 
 
 36 
 
 
 26.1 
 
 22.6 
 
 83 
 
 36.8 
 
 60.3 
 
 524 
 
 37 
 
 16.3 
 
 26.8 
 
 23-3 
 
 84 
 
 37-2 
 
 61.1 
 
 53-0 
 
 38 
 
 16.8 
 
 27-5 
 
 23.9 
 
 85 
 
 37-7 
 
 61.8 
 
 53-6 
 
 39 
 
 17.2 
 
 28.3 
 
 24.5 
 
 86 
 
 38.1 
 
 62.5 
 
 54-3 
 
 40 
 
 17.6 
 
 29.0 
 
 25.2 
 
 87 
 
 38.5 
 
 63.3 
 
 54-9 
 
 41 
 
 18.1 
 
 29.7 
 
 25-8 
 
 88 
 
 39-o 
 
 64.0 
 
 55-5 
 
 42 
 
 18.5 
 
 30.5 
 
 26.4 
 
 89 
 
 394 
 
 64.7 
 
 56.2 
 
 43 
 
 19.0 
 
 31-2 
 
 2 7 .I 
 
 90 
 
 39-9 
 
 65.5 
 
 56.8 
 
 44 
 
 19.4 
 
 31-9 
 
 27.7 
 
 91 
 
 40.3 
 
 66.2 
 
 574 
 
 45 
 
 19.9 
 
 32.7 
 
 28.3 
 
 92 
 
 40.8 
 
 66.9 
 
 58.1 
 
 46 
 
 20.3 
 
 334 
 
 29.0 
 
 93 
 
 41.2 
 
 67.7 
 
 58.7 
 
 47 
 
 20.7 
 
 34-1 
 
 29.6 
 
 94 
 
 41.7 
 
 68.4 
 
 59-3 
 
 48 
 
 21.2 
 
 34-8 
 
 3O.2 
 
 95 
 
 42.1 
 
 69.1 
 
 60.0 
 
 49 
 
 21.6 
 
 35-5 
 
 30.8 
 
 96 
 
 42.5 
 
 69.9 
 
 60.6 
 
 50 
 
 22.1 
 
 36-2 
 
 3L5 
 
 97 
 
 43- 
 
 70.6 
 
 61.2 
 
 51 
 
 22.5 
 
 37-0 
 
 32.1 
 
 98 
 
 434 
 
 71.3 
 
 61.9 
 
 52 
 
 23.0 
 
 37-7 
 
 32.7 
 
 99 
 
 43-9 
 
 72.1 
 
 62.5 
 
 53 
 
 234 
 
 384 
 
 33-3 
 
 100 
 
 444 
 
 72.8 
 
 63.2 
 
 54 
 
 23.8 
 
 39-2 
 
 34-0 
 
 101 
 
 44.8 
 
 73-5 
 
 63-8 
 
 55 
 
 24.2 
 
 39-9 
 
 34-6 
 
 102 
 
 45-3 
 
 74-3 
 
 64.4 
 
 56 
 
 24.7 
 
 40.5 
 
 35-2 
 
 I0 3 
 
 45-7 
 
 75-0 
 
 65-1 
 
 57 
 58 
 
 25.1 
 
 25'5 
 
 41-3 
 42.1 
 
 Hi 
 
 104 
 105 
 
 46.2 
 46.6 
 
 75-7 
 76.5 
 
 65-7 
 66.3 
 
 59 
 
 26.0 
 
 42.8 
 
 37.1 
 
 106 
 
 47.0 
 
 77.2 
 
 67.0 
 
 60 
 
 26.4 
 
 43-5 
 
 37-8 
 
 107 
 
 47-5 
 
 77-9 
 
 67.6 
 
 61 
 
 26.9 
 
 44-3 
 
 384 
 
 108 
 
 48.0 
 
 78.7 
 
 68.2 
 
 62 
 
 27-3 
 
 
 39-0 
 
 109 
 
 48.4 
 
 794 
 
 68.9 
 
 63 
 
 2 7 .8 
 
 45-7 
 
 39-7 
 
 no 
 
 48.9 
 
 80.1 
 
 69.5 
 
 64 
 
 28.2 
 
 4 6 -5 
 
 40.3 
 
 in 
 
 49-3 
 
 80.9 
 
 70.1 
 
 65 
 
 28.7 
 
 47.2 
 
 40.9 
 
 112 
 
 49-8 
 
 81.6 
 
 70.8 
 
 66 
 
 29.1 
 
 47-9 
 
 41.6 
 
 "3 
 
 50.2 
 
 82.3 
 
 71.4 
 
 67 
 
 29.5 
 
 48.6 
 
 42.2 
 
 114 
 
 50.7 
 
 83-1 
 
 72.0 
 
 68 
 
 30.0 
 
 494 
 
 42.8 
 
 115 
 
 
 83.8 
 
 72.7 
 
 69 
 
 304 
 
 50.1 
 
 43-5 
 
 116 
 
 51*6 
 
 84-5 
 
 73-3 
 
 70 
 
 3-9 
 
 ^0.8 
 
 44.1 
 
 117 
 
 52.0 
 
 85.2 
 
 74.0 
 
 71 
 
 3^3 
 
 51-6 
 
 44-7 
 
 118 
 
 524 
 
 85.9 
 
 74.6 
 
 72 
 
 31-8 
 
 52.3 
 
 454 
 
 119 
 
 52.9 
 
 86.6 
 
 75-2 
 
 73 
 
 32.2 
 
 53-0 
 
 46.0 
 
 120 
 
 53-3 
 
 87.4 
 
 
 74 
 
 32.6 
 
 53-8 
 
 46.6 
 
 121 
 
 53-8 
 
 88.1 
 
 76.6 
 
 75 
 
 33-1 
 
 54-5 
 
 47-3 
 
 122 
 
 54-2 
 
 88.9 
 
 77.2 
 
 76 
 
 33-5 
 
 55-2 
 
 47-9 
 
 123 54-7 
 
 89.6 
 
 77-9 
 
TABLES 
 
 305 
 
 PARTS COPPER 
 OXIDE 
 
 PARTS 
 DEXTROSE 
 
 PARTS 
 MALTOSE 
 
 PARTS 
 LACTOSE 
 
 PARTS COPPER 
 OXIDE 
 
 PARTS 
 DEXTROSE 
 
 PARTS 
 MALTOSE 
 
 PARTS 
 LACTOSE 
 
 124 
 
 55-1 
 
 90.3 
 
 78.5 
 
 178 
 
 79-5 
 
 130.3 
 
 "3-3 
 
 I2 5 
 
 55-6 
 
 91.1 
 
 79.1 
 
 179 
 
 80.0 
 
 131.0 
 
 II3-9 
 
 126 
 
 56.0 
 
 91.8 
 
 79.8 
 
 180 
 
 80.4 
 
 131.8 
 
 114.6 
 
 127 
 
 56.5 
 
 92.5 
 
 80.4 
 
 181 
 
 80.8 
 
 132.5 
 
 115.2 
 
 128 
 
 56-9 
 
 93-3 
 
 81.1 
 
 182 
 
 81.3 
 
 133-2 
 
 115.8 
 
 129 
 
 57-3 
 
 94.0 
 
 81.7 
 
 183 
 
 81.8 
 
 134.0 
 
 116.5 
 
 130 
 
 57-8 
 
 94-8 
 
 82.4 
 
 184 
 
 82.2 
 
 134-7 
 
 117.1 
 
 I 3 I 
 
 58.2 
 
 95-5 
 
 83.0 
 
 185 
 
 82.7 
 
 *35-5 
 
 117.8 
 
 132 
 
 58.7 
 
 96.2 
 
 83.6 
 
 186 
 
 83.1 
 
 136.2 
 
 118.4 
 
 133 
 
 59-1 
 
 97.0 
 
 84.2 
 
 187 
 
 83.5 
 
 136.9 
 
 119.1 
 
 J 34 
 
 59-6 
 
 97-7 
 
 84.9 
 
 188 
 
 84.0 
 
 137.7 
 
 119.7 
 
 *35 
 
 60.0 
 
 98.4 
 
 85.5 
 
 189 
 
 84.4 
 
 138.4 
 
 120.4 
 
 136 
 
 60.5 
 
 99.2 
 
 86.1 
 
 190 
 
 84.9 
 
 I39.I 
 
 I2I.O 
 
 137 
 
 60.9 
 
 99.9 
 
 86.8 
 
 191 
 
 854 
 
 139.9 
 
 I2I.7 
 
 138 
 
 61.3 
 
 100.7 
 
 87.4 
 
 192 
 
 85.9 
 
 140.6 
 
 122.3 
 
 139 
 
 61.8 
 
 101.4 
 
 88.1 
 
 193 
 
 86.3 
 
 141.4 
 
 123.0 
 
 140 
 
 62.2 
 
 102. 1 
 
 88.7 
 
 194 
 
 86.8 
 
 142.1 
 
 123.6 
 
 141 
 
 62.7 
 
 102.8 
 
 89.3 
 
 195 
 
 87.2 
 
 142.8 
 
 124.3 
 
 142 
 
 63.1 
 
 103.5 
 
 90.0 
 
 196 
 
 87.7 
 
 143.6 
 
 124.9 
 
 143 
 
 63.6 
 
 104.3 
 
 90.6 
 
 197 
 
 88.1 
 
 144.3 
 
 125.6 
 
 144 
 
 64.0 
 
 105.0 
 
 91-3 
 
 198 
 
 88.6 
 
 I45-I 
 
 126.2 
 
 145 
 
 64-5 
 
 105.8 
 
 91.9 
 
 199 
 
 89.0 
 
 145.8 
 
 126.9 
 
 146 
 
 64.9 
 
 106.5 
 
 92.6 
 
 200 
 
 89.5 
 
 146.6 
 
 127.5 
 
 147 
 
 65-4 
 
 107.2 
 
 93-2 
 
 201 
 
 89.9 
 
 147-3 
 
 128.2 
 
 148 
 
 65.8 
 
 108.0 
 
 93-9 
 
 202 
 
 90.4 
 
 148.1 
 
 128.8 
 
 149 
 
 66.3 
 
 108.7 
 
 94-5 
 
 20 3 
 
 90.8 
 
 148.8 
 
 129.5 
 
 15 
 
 66.8 
 
 109.5 
 
 95-2 
 
 204 
 
 91-3 
 
 149.6 
 
 I30.I 
 
 151 
 
 67-3 
 
 1 10.2 
 
 95-8 
 
 205 
 
 91.7 
 
 150-3 
 
 130.8 
 
 152 
 
 67.7 
 
 1 1 1.0 
 
 96.5 
 
 206 
 
 92.2 
 
 151.1 
 
 I3L5 
 
 153 
 
 68.3 
 
 111.7 
 
 97.1 
 
 207 
 
 92.6 
 
 151.8 
 
 I32.I 
 
 154 
 
 68.7 
 
 112.4 
 
 97-8 
 
 208 
 
 93-1 
 
 152.5 
 
 132.8 
 
 155 
 
 69.2 
 
 113.2 
 
 984 
 
 20 9 
 
 93-5 
 
 153.3 
 
 !334 
 
 J 56 
 
 69.6 
 
 113.9 
 
 99.1 
 
 2IO 
 
 94.0 
 
 i54.i 
 
 I34.I 
 
 157 
 
 70.0 
 
 114.7 
 
 99-7 
 
 211 
 
 944 
 
 154.8 
 
 134.7 
 
 158 
 
 70.5 
 
 "54 
 
 100.4 
 
 212 
 
 94.9 
 
 155.6 
 
 1354 
 
 159 
 
 70.9 
 
 116.1 
 
 10 1. 
 
 213 
 
 95-3 
 
 156-3 
 
 136.0 
 
 160 
 
 71-3 
 
 116.9 
 
 101.7 
 
 2I 4 
 
 95-8 
 
 I57-I 
 
 136.7 
 
 161 
 
 71.8 
 
 117.6 
 
 102.3 
 
 215 
 
 96.3 
 
 157.8 
 
 137.3 
 
 162 
 
 72.3 
 
 118.4 
 
 103.0 
 
 216 
 
 96.7 
 
 158.6 
 
 138.0 
 
 163 
 
 72.7 
 
 119.1 
 
 103.6 
 
 217 
 
 97-2 
 
 159.3 
 
 138.6 
 
 164 
 
 73-2 
 
 119.9 
 
 104.3 
 
 218 
 
 97.6 
 
 1 60.0 
 
 139.3 
 
 165 
 
 73-6 
 
 120.6 
 
 104.9 
 
 219 
 
 98.1 
 
 160.8 
 
 139.9 
 
 166 
 
 74.1 
 
 121.4 
 
 105.6 
 
 220 
 
 98.6 
 
 161.5 
 
 140.6 
 
 167 
 
 74-5 
 
 1 22. 1 
 
 106.2 
 
 221 
 
 99.0 
 
 162.3 
 
 141.2 
 
 1 68 
 
 74-9 
 
 122.9 
 
 106.9 
 
 222 
 
 99-5 
 
 163.0 
 
 141.9 
 
 169 
 
 754 
 
 123.6 
 
 107.5 
 
 223 
 
 99.9 
 
 163.7 
 
 142.5 
 
 170 
 
 75-8 
 
 1244 
 
 108.2 
 
 22 4 
 
 100.4 
 
 164.5 
 
 143.2 
 
 171 
 
 76.3 
 
 I25.I 
 
 108.8 
 
 225 
 
 100.9 
 
 165.3 
 
 143.8 
 
 172 
 
 76.8 
 
 125.8 
 
 109.5 
 
 226 
 
 101.3 
 
 166.0 
 
 144-5 
 
 173 
 
 77.3 
 
 126.6 
 
 1 10. 1 
 
 227 
 
 101.8 
 
 166.8 
 
 I45-I 
 
 174 
 
 77-7 
 
 127.3 
 
 1 10.8 
 
 228 
 
 102.2 
 
 167.5 
 
 145.8 
 
 175 
 
 78.2 
 
 I28.I 
 
 111.4 
 
 229 
 
 102.7 
 
 168.3 
 
 146.4 
 
 176 
 
 78.6 
 
 128.8 
 
 1 12.0 
 
 2 3 
 
 I03.I 
 
 169.1 
 
 147.0 
 
 177 
 
 79.1 
 
 129.5 
 
 1 1 2.6 
 
 2 3 T 
 
 103.6 
 
 169.8 
 
 147.7 
 
306 
 
 TABLES 
 
 PARTS COPPER 
 OXIDE 
 
 PARTS 
 DEXTROSE 
 
 PARTS 
 
 MALTOSE 
 
 PARTS 
 LACTOSE 
 
 PARTS COPPER 
 OXIDE 
 
 PARTS 
 DEXTROSE 
 
 PARTS 
 MALTOSE 
 
 PARTS 
 LACTOSE 
 
 232 
 
 104.0 
 
 170.6 
 
 148.3 
 
 277 
 
 124.6 
 
 204.5 
 
 177.6 
 
 233 
 
 104.5 
 
 I7L3 
 
 149.0 
 
 278 
 
 125.1 
 
 205.2 
 
 178.3 
 
 234 
 
 105.0 
 
 172.1 
 
 149.6 
 
 279 
 
 125.6 
 
 206.0 
 
 178.9 
 
 235 
 
 105.4 
 
 172.8 
 
 150.3 
 
 280 
 
 126.1 
 
 206.8 
 
 179.6 
 
 236 
 
 105-9 
 
 173.6 
 
 150.9 
 
 281 
 
 126.5 
 
 207.5 
 
 180.2 
 
 237 
 
 106.3 
 
 174-3 
 
 151.6 
 
 282 
 
 127.0 
 
 208.3 
 
 180.9 
 
 238 
 
 106.8 
 
 I75.I 
 
 152.2 
 
 283 
 
 127.4 
 
 209.0 
 
 181.5 
 
 239 
 
 107.2 
 
 175-8 
 
 152.9 
 
 284 
 
 127.9 
 
 209.8 
 
 182.2 
 
 240 
 
 107.7 
 
 176.6 
 
 153-5 
 
 285 
 
 128.3 
 
 210.5 
 
 182.9 
 
 241 
 
 I08.I 
 
 177-3 
 
 154.2 
 
 286 
 
 128.8 
 
 211.3 
 
 183.6 
 
 242 
 
 108.6 
 
 178.1 
 
 154.8 
 
 287 
 
 129.3 
 
 2I2.I 
 
 184.2 
 
 243 
 
 109.0 
 
 178.8 
 
 155.5 
 
 288 
 
 129.7 
 
 212.8 
 
 184.9 
 
 244 
 
 109.5 
 
 179.6 
 
 156.1 
 
 289 
 
 130.2 
 
 213.6 
 
 185.6 
 
 245 
 
 109.9 
 
 180.3 
 
 156.8 
 
 290 
 
 130.6 
 
 214-3 
 
 186.2 
 
 246 
 
 110.4 
 
 181.1 
 
 157-4 
 
 291 
 
 131.1 
 
 2I5.I 
 
 186.9 
 
 247 
 
 110.9 
 
 181.8 
 
 158.1 
 
 292 
 
 I3L5 
 
 * 215.9 
 
 187.6 
 
 248 
 
 IH.3 
 
 182.6 
 
 158.7 
 
 293 
 
 132.0 
 
 216.6 
 
 188.2 
 
 249 
 
 iii.S 
 
 183-3 
 
 159-4 
 
 294 
 
 J 32-5 
 
 217.4 
 
 188.9 
 
 250 
 
 112.3 
 
 184.1 
 
 160.0 
 
 295 
 
 !33.o 
 
 218.2 
 
 189.5 
 
 251 
 
 112.7 
 
 184.8 
 
 160.7 
 
 296 
 
 133-4 
 
 218.9 
 
 190.2 
 
 252 
 
 113.2 
 
 185.5 
 
 161.3 
 
 297 
 
 133.9 
 
 219.7 
 
 190.8 
 
 253 
 
 II3-7 
 
 186.3 
 
 162.0 
 
 298 
 
 !343 
 
 220.4 
 
 J 9i-5 
 
 254 
 
 114.1 
 
 187.1 
 
 162.6 
 
 299 
 
 134.8 
 
 221.2 
 
 192.1 
 
 255 
 
 114.6 
 
 187.8 
 
 163-3 
 
 300 
 
 135-3 
 
 221.9 
 
 192.8 
 
 256 
 
 115.0 
 
 188.6 
 
 163.9 
 
 301 
 
 135-7 
 
 222.7 
 
 193-4 
 
 257 
 
 II5-5 
 
 189.3 
 
 164.6 
 
 302 
 
 136.2 
 
 223.5 
 
 194.1 
 
 258 
 
 116.0 
 
 190.1 
 
 165.2 
 
 303 
 
 136.6 
 
 224.2 
 
 194.7 
 
 259 
 
 116.4 
 
 190.8 
 
 165.9 
 
 34 
 
 I37.I 
 
 225.0 
 
 J 95-3 
 
 260 
 
 116.9 
 
 191.6 
 
 166.5 
 
 305 
 
 137.6 
 
 225.8 
 
 196.0 
 
 261 
 
 II7-3 
 
 192.4 
 
 167.2 
 
 306 
 
 138.0 
 
 226.5 
 
 196.6 
 
 262 
 
 117.8 
 
 I93.I 
 
 167.8 
 
 37 
 
 138.5 
 
 227.3 
 
 197-3 
 
 263 
 
 118.3 
 
 193-9 
 
 168.1 
 
 308 
 
 138.9 
 
 228.1 
 
 197.9 
 
 264 
 
 118.7 
 
 194.6 
 
 169.5 
 
 309 
 
 139.4 
 
 228.8 
 
 198.6 
 
 265 
 
 119.2 
 
 1954 
 
 169.8 
 
 310 
 
 139.9 
 
 229.6 
 
 199.3 
 
 266 
 
 119.6 
 
 196.1 
 
 170.4 
 
 3H 
 
 140.3 
 
 230.4 
 
 199.9 
 
 267 
 
 1 20. 1 
 
 196.9 
 
 171.1 
 
 312 
 
 140.8 
 
 23I.I 
 
 200.6 
 
 268 
 
 120.6 
 
 197.7 
 
 171.7 
 
 313 
 
 141.2 
 
 231.9 
 
 201.3 
 
 269 
 
 I2I.O 
 
 198.4 
 
 172.4 
 
 314 
 
 141.7 
 
 232.7 
 
 202.0 
 
 270 
 
 I2I.4 
 
 199.2 
 
 173.0 
 
 315 
 
 142.2 
 
 233-4 
 
 202.6 
 
 271 
 
 I2I.9 
 
 199.9 
 
 173-7 
 
 316 
 
 142.6 
 
 234.2 
 
 203.3 
 
 272 
 
 122.4 
 
 200.7 
 
 174.4 
 
 317 
 
 143. i 
 
 234-9 
 
 203.9 
 
 273 
 
 122.8 
 
 201.5 
 
 175.0 
 
 318 
 
 143.6 
 
 235-7 
 
 204.6 
 
 274 
 
 123.3 
 
 2O2.2 
 
 175-7 
 
 319 
 
 144.0 
 
 236.5 
 
 205.3 
 
 275 
 
 123.7 
 
 203.0 
 
 176.3 
 
 320 
 
 144.5 
 
 237.2 
 
 205.9 
 
 276 
 
 124.2 
 
 203.7 
 
 177.0 
 
 
 
 
 
TABLES 
 
 307 
 
 5. CALCULATED VALUES OF CUPRIC-REDUCING POWERS AND 
 PARTS OF MALTOSE, DEXTROSE, AND DEXTRIN PER UNIT 
 OF CARBOHYDRATE FOR EACH DEGREE OF ROTATION 
 OF A NORMALLY ACID HYDROLYZED STARCH SOLUTION 
 
 r a p 
 
 1 J D 3 86 
 
 * 3 86* 
 
 m 
 
 3 86 
 
 V 
 
 A 
 
 386 
 
 195 
 
 0.000 
 
 0.000 
 
 0.000 
 
 1. 000 
 
 194 
 
 O.OII 
 
 0.017 
 
 O.OOI 
 
 0.982 
 
 193 
 
 0.022 
 
 0.038 
 
 0.00 1 
 
 0.966 
 
 192 
 
 0.032 
 
 0.052 
 
 O.OOI 
 
 0.947 
 
 I 9 I 
 
 0.041 
 
 0.068 
 
 0.002 
 
 0.930 
 
 I9O 
 
 0.051 
 
 0.084 
 
 0.002 
 
 0.914 
 
 189 
 
 0.061 
 
 0.098 
 
 O.OO2 
 
 0.900 
 
 188 
 
 0.071 
 
 0.114 
 
 0.003 
 
 0.883 
 
 187 
 
 0.081 
 
 0.128 
 
 OiOOS 
 
 0.869 
 
 186 
 
 0.090 
 
 0.143 
 
 0.005 
 
 0.852 
 
 185 
 
 O.IOO 
 
 0.157 
 
 0.005 
 
 0.838 
 
 184 
 
 0.109 
 
 0.170 
 
 0.008 
 
 0.822 
 
 183 
 
 0.118 
 
 0.183 
 
 0.010 
 
 0.807 
 
 182 
 
 0.127 
 
 0.195 
 
 O.OI2 
 
 0.793 
 
 181 
 
 0.137 
 
 0.207 
 
 0.014 
 
 0.779 
 
 180 
 
 0.146 
 
 0.219 
 
 0.016 
 
 0.765 
 
 179 
 
 0.155 
 
 0.227 
 
 0.019 
 
 0.754 
 
 178 
 
 0.164 
 
 0.237 
 
 0.022 
 
 0.741 
 
 177 
 
 0.173 
 
 0.247 
 
 O.O24 
 
 0.729 
 
 176 
 
 0.182 
 
 0.257 
 
 0.027 
 
 0.716 
 
 175 
 
 0.191 
 
 0.266 
 
 O.O3I 
 
 0.705 
 
 174 
 
 0.199 
 
 0.274 
 
 0.034 
 
 0.692 
 
 173 
 
 0.207 
 
 0.282 
 
 0.038 
 
 0.680 
 
 172 
 
 0.216 
 
 0.290 
 
 0.042 
 
 0.668 
 
 171 
 
 0.224 
 
 0.298 
 
 0.046 
 
 0.656 
 
 170 
 
 0.233 
 
 0.305 
 
 0.050 
 
 0.645 
 
 169 
 
 0.242 
 
 0.312 
 
 0.053 
 
 0.635 
 
 168 
 
 0.251 
 
 0.318 
 
 0.056 
 
 0.625 
 
 167 
 
 0.259 
 
 0.325 
 
 0.060 
 
 0.615 
 
 166 
 
 0.267 
 
 0.331 
 
 0.064 
 
 0.605 
 
 165 
 
 0.275 
 
 0.337 
 
 0.068 
 
 o-595 
 
 164 
 
 0.283 
 
 0.343 
 
 0.073 
 
 0.584 
 
 163 
 
 0.292 
 
 0.350 
 
 0.076 
 
 0.572 
 
 162 
 
 0.300 
 
 0.356 
 
 0.083 
 
 0.561 
 
 161 
 
 0.308 
 
 0.362 
 
 0.088 
 
 o-55o 
 
 160 
 
 0.316 
 
 0.367 
 
 0.093 
 
 0.540 
 
 159 
 
 0.324 
 
 0.374 
 
 0.098 
 
 0.528 
 
 158 
 
 0.332 
 
 0.381 
 
 O.IO2 
 
 0-517 
 
 157 
 
 0.340 
 
 0.387 
 
 0.106 
 
 0.507 
 
 156 
 
 0.348 
 
 0.392 
 
 O.IIO 
 
 0.498 
 
 155 
 
 0-356 
 
 0.397 
 
 0.115 
 
 0.488 
 
 154 
 
 0-365 
 
 0.402 
 
 O.I2O 
 
 0.478 
 
 153 
 
 0-373 
 
 0.407 
 
 0.125 
 
 0.468 
 
 * Obtained by Defren's Reduction Method. 
 
308 
 
 TABLES 
 
 fal 20 
 
 1 J D 386 
 
 *386 
 
 m 
 
 386 
 
 .% 
 
 A 386 
 
 152 
 
 0.381 
 
 0.412 
 
 0.130 
 
 0.458 
 
 151 
 
 0.389 
 
 0.414 
 
 o.i35 
 
 0.451 
 
 150 
 
 0-397 
 
 0.421 
 
 0.140 
 
 0-439 
 
 149 
 
 0.404 
 
 0.425 
 
 0.146 
 
 0.429 
 
 148 
 
 0.412 
 
 0.429 
 
 0.152 
 
 0.419 
 
 147 
 
 0.419 
 
 0.432 
 
 0.158 
 
 0.410 
 
 146 
 
 0.427 
 
 o-434 
 
 0.163 
 
 0.403 
 
 145 
 
 0-435 
 
 0.436 
 
 0.169 
 
 0-395 
 
 144 
 
 0.442 
 
 0-439 
 
 0.175 
 
 0.386 
 
 143 
 
 0.450 
 
 0.442 
 
 0.183 
 
 0-375 
 
 142 
 
 0.458 
 
 0.445 
 
 0.188 
 
 0.367 
 
 I 4 I 
 
 0.465 
 
 0.448 
 
 0.193 
 
 0-359 
 
 140 
 
 0-473 
 
 0.450 
 
 0.199 
 
 0.351 
 
 139 
 
 0.481 
 
 0.452 
 
 0.206 
 
 0.342 
 
 138 
 
 0.488 
 
 0.454 
 
 0.212 
 
 0.334 
 
 137 
 
 0.496 
 
 0.456 
 
 O.2I9 
 
 0.325 
 
 136 
 
 0.503 
 
 0.458 
 
 0.224 
 
 0.318 
 
 J 35 
 
 0.510 
 
 0.459 
 
 O.23O 
 
 0.3II 
 
 134 
 
 OW 
 
 0-459 
 
 0.237 
 
 0.304 
 
 i33 
 
 0.524 
 
 0.460 
 
 0.244 
 
 0.296 
 
 132 
 
 0-531 
 
 0.460 
 
 0.250 
 
 0.290 
 
 131 
 
 0.538 
 
 0.461 
 
 0.257 
 
 0.282 
 
 130 
 
 0.546 
 
 0.462 
 
 0.264 
 
 0.274 
 
 129 
 128 
 
 0-553 
 0.560 
 
 0.462 
 0.462 
 
 O.272 
 0.279 
 
 0.266 
 0.258 
 
 127 
 
 0.567 
 
 0.461 
 
 0.287 
 
 0-253 
 
 126 
 
 0-574 
 
 0.460 
 
 0.294 
 
 0.246 
 
 125 
 
 0.580 
 
 0.460 
 
 0.301 
 
 0.239 
 
 124 
 
 0.588 
 
 0.459 
 
 0.308 
 
 0.233 
 
 123 
 
 0-595 
 
 0.458 
 
 0.315 
 
 0.227 
 
 122 
 
 0.602 
 
 0.456 
 
 0.323 
 
 0.221 
 
 121 
 
 0.608 
 
 0-455 
 
 0.331 
 
 O.2I4 
 
 I2O 
 
 0.614 
 
 0-453 
 
 0.338 
 
 0.209 
 
 119 
 
 0.621 
 
 o.45i 
 
 0.346 
 
 0.203 
 
 118 
 
 0.628 
 
 0.450 
 
 0-354 
 
 0.196 
 
 II 7 
 
 0-635 
 
 0.448 
 
 0.361 
 
 O.I9I 
 
 116 
 
 0.642 
 
 0.446 
 
 0.369 
 
 0.185 
 
 "5 
 
 0.649 
 
 0.444 
 
 0.377 
 
 0.178 
 
 114 
 
 0.656 
 
 0.442 
 
 0.387 
 
 O.I7I 
 
 113 
 
 0.663 
 
 0.439 
 
 0-395 
 
 0.166 
 
 112 
 
 0.669 
 
 0.436 
 
 0.403 
 
 0.161 
 
 III 
 
 0.675 
 
 o-433 
 
 0.4II 
 
 0.156 
 
 1 10 
 
 0.681 
 
 0.429 
 
 0.420 
 
 0.152 
 
 109 
 
 0.687 
 
 0.425 
 
 0.428 
 
 0147 
 
 108 
 
 0.694 
 
 0.421 
 
 0.436 
 
 0.143 
 
 107 
 
 0.700 
 
 0.418 
 
 0-445 
 
 0.137 
 
 106 
 
 0.707 
 
 0.414 
 
 0-453 
 
 0.133 
 
 105 
 
 0.713 
 
 0.411 
 
 0.462 
 
 0.127 
 
 104 
 
 0.719 
 
 0.407 
 
 0.471 
 
 O.I22 
 
 103 
 
 0.725 
 
 0.402 
 
 0.480 
 
 O.II8 
 
 102 
 
 0.732 
 
 0.398 
 
 0.489 
 
 O.II3 
 
 101 
 
 0.738 
 
 0-393 
 
 0.498 
 
 0.109 
 
 100 
 
 0.744 
 
 0.389 
 
 0.508 
 
 0.103 
 
 99 
 
 0.75 
 
 0.384 
 
 0.518 
 
 0.099 
 
TABLES 
 
 309 
 
 [a] 20 
 J D 3 86 
 
 V 
 
 m 
 
 386 
 
 ** 
 
 A 
 
 386 
 
 98 
 
 0-757 
 
 0.380 
 
 0.527 
 
 0.093 
 
 97 
 
 0.763 
 
 0-374 
 
 0.536 
 
 0.090 
 
 96 
 
 0.769 
 
 0.368 
 
 0.545 
 
 0.087 
 
 95 
 
 0-775 
 
 0.362 
 
 0.554 
 
 0.084 
 
 94 
 
 0.781 
 
 0-357 
 
 0.563 
 
 0.080 
 
 93 
 
 0.787 
 
 0-352 
 
 0.572 
 
 0.076 
 
 92 
 
 0-793 
 
 0-347 
 
 0.581 
 
 0.072 
 
 9i 
 
 0.799 
 
 0.342 
 
 0.591 
 
 0.068 
 
 90 
 
 0.805 
 
 0.336 
 
 0.600 
 
 0.064 
 
 89 
 
 0.810 
 
 0.329 
 
 0.610 
 
 0.061 
 
 88 
 
 0.816 
 
 0.322 
 
 0.620 
 
 0.058 
 
 87 
 
 0.822 
 
 0.315 
 
 0.630 
 
 o-055 
 
 86 
 
 0.828 
 
 0.308 
 
 0.640 
 
 0.052 
 
 85 
 
 0.834 
 
 0.302 
 
 0.650 
 
 0.048 
 
 84 
 
 0.839 
 
 0.294 
 
 0.660 
 
 0.044 
 
 83 
 
 0.844 
 
 0.287 
 
 0.670 
 
 0.043 
 
 82 
 
 0.850 
 
 0.279 
 
 0.680 
 
 0.041 
 
 81 
 
 0.856 
 
 0.272 
 
 0.690 
 
 0.038 
 
 80 
 
 0.862 
 
 0.264 
 
 0.701 
 
 0.035 
 
 79 
 
 0.867 
 
 0.256 
 
 0.712 
 
 0.032 
 
 78 
 
 0.872 
 
 0.247 
 
 0.722 
 
 0.031 
 
 77 
 
 0.878 
 
 0.237 
 
 0-733 
 
 0.030 
 
 76 
 
 0.884 
 
 0.228 
 
 0.744 
 
 0.028 
 
 75 
 
 0.889 
 
 0.219 
 
 0-755 
 
 0.026 
 
 74 
 
 0.895 
 
 0.210 
 
 0.766 
 
 0.024 
 
 73 
 
 0.901 
 
 0.199 
 
 0.778 
 
 0.023 
 
 72 
 
 0.906 
 
 0.189 
 
 0.789 
 
 0.022 
 
 7 1 
 
 0.911 
 
 0.179 
 
 0.801 
 
 0.02O 
 
 70 
 
 0.916 
 
 0.170 
 
 0.811 
 
 O.OI8 
 
 69 
 
 0.921 
 
 0.159 
 
 0.824 
 
 0.017 
 
 68 
 
 0.926 
 
 0.149 
 
 0.835 
 
 0.016 
 
 67 
 
 0.932 
 
 0.139 
 
 0.846 
 
 0.015 
 
 66 
 65 
 
 0-937 
 0.942 
 
 0.130 
 O.I2I 
 
 0.856 
 0.867 
 
 0.014 
 O.OI2 
 
 64 
 
 0.947 
 
 O.IIO 
 
 0.879 
 
 O.OII 
 
 63 
 
 0.952 
 
 0.099 
 
 0.890 
 
 O.OII 
 
 62 
 
 0-957 
 
 0.088 
 
 0.902 
 
 O.OIO 
 
 61 
 
 0.962 
 
 0.078 
 
 0.914 
 
 0.008 
 
 60 
 
 0.967 
 
 0.068 
 
 0.926 
 
 0.006 
 
 59 
 
 0.972 
 
 0.57 
 
 0-937 
 
 O.OO6 
 
 58 
 
 0.977 
 
 0.047 
 
 0.948 
 
 0.005 
 
 57 
 
 0.982 
 
 0.036 
 
 0.960 
 
 O.OO4 
 
 56 
 
 0.987 
 
 0.025 
 
 0.971 
 
 0.004 
 
 55 
 
 0.992 
 
 O.OI5 
 
 0.982 
 
 0.003 
 
 54 
 
 0.997 
 
 0.005 
 
 0-993 
 
 0.002 
 
 53 
 
 1. 000 
 
 o.ooo 
 
 I.OOO 
 
 O.OOO 
 
3io 
 
 TABLES 
 
 6. DENSITY OF WATER AT DIFFERENT TEMPERATURES 
 
 TEMPERATURE: 
 DEGREES CENTIGRADE 
 
 DENSITY OF WATER 
 RELATIVE TO ITS DEN- 
 SITY AT 4 C. 
 
 TEMPERATURE: 
 DEGREES CENTIGRADE 
 
 DENSITY OF WATER 
 RELATIVE TO ITS DEN- 
 SITY AT 4 C. 
 
 
 
 0.99987 
 
 27 
 
 0.99660 
 
 I 
 
 0.99993 
 
 28 
 
 0.99633 
 
 2 
 
 0.99997 
 
 29 
 
 0.99605 
 
 3 
 
 0.99999 
 
 30 
 
 0-99577 
 
 4 
 
 1. 00000 
 
 31 
 
 0.99547 
 
 5 
 
 0.99999 
 
 32 
 
 0.99517 
 
 6 
 
 0.99997 
 
 33 
 
 0.99485 
 
 7 
 
 0.99993 
 
 34 
 
 0.99452 
 
 8 
 
 0.99989 
 
 35 
 
 0.99418 
 
 9 
 
 0.99982 
 
 36 
 
 0.99383 
 
 10 
 
 0.99975 
 
 37 
 
 0-99347 
 
 ii 
 
 0.99966 
 
 38 
 
 0.99310 
 
 12 
 
 0.99955 
 
 39 
 
 0.99273 
 
 13 
 
 0.99943 
 
 40 
 
 0.99235 
 
 14 
 
 0.99930 
 
 41 
 
 0.99197 
 
 15 
 
 0.99916 
 
 42 
 
 0.99158 
 
 15.5 
 
 0.99908 
 
 43 
 
 0.99II8 
 
 16 
 
 0.99900 
 
 44 
 
 0.99078 
 
 17 
 
 0.99884 
 
 45 
 
 0.99037 
 
 17.5 
 
 0.99875 
 
 46 
 
 0.98996 
 
 18 
 
 0.99865 
 
 47 
 
 0.98954 
 
 19 
 
 0.99846 
 
 48 
 
 o 98910 
 
 20 
 
 0.99826 
 
 49 
 
 0.98865 
 
 21 
 
 0.99805 
 
 5 
 
 0.98819 
 
 22 
 
 0.99783 
 
 00 
 
 0.98334 
 
 23 
 
 0.99760 
 
 70 
 
 0.97790 
 
 24 
 
 0.99737 
 
 80 
 
 0.97191 
 
 25 
 
 0.99712 
 
 90 
 
 0.96550 
 
 26 
 
 0.99687 
 
 100 
 
 0.95863 
 
 The temperature readings are those given by a mercury thermometer. 
 Landolt's table refers to hydrogen thermometer readings. The readings of 
 the two thermometers agree at o and 100. At 20 the mercury thermometer 
 reads about 0.1 less than the hydrogen. 
 
TABLES 
 
 7. VOLUMES OF SUGAR SOLUTIONS AT TEMPERATURES 
 
 BETWEEN o AND 100 C (Mercury thermometer} 
 
 (Volume at o = i. Gerlach.) 
 
 TEMP. 
 C. 
 
 0% 
 
 5% 
 
 10% 
 
 15% 
 
 20% 
 
 25% 
 
 30% 
 
 35% 
 
 
 
 1. 00000 
 
 1. 00000 
 
 1. 00000 
 
 i .00000 
 
 I.OOOOO 
 
 I.OOOOO 
 
 I.OOOOO 
 
 I.OOOOO 
 
 5 
 
 0.99989 
 
 1.00013 
 
 1.00028 
 
 1.00043 
 
 1.00053 
 
 1.00063 
 
 1.00083 
 
 1.00093 
 
 10 
 
 1.00013 
 
 1.00046 
 
 1.00076 
 
 1.00106 
 
 1.00136 
 
 1.00161 
 
 1.00186 
 
 1.00216 
 
 15 
 
 1.00070 
 
 1.00114 
 
 1.00159 
 
 1.00199 
 
 1.00239 
 
 1.00289 
 
 1.00319 
 
 1.00359 
 
 17-5 
 
 I.OOIIO 
 
 1.00170 
 
 I.002IO 
 
 1.00260 
 
 1.00305 
 
 L00355 
 
 1.00405 
 
 1.00445 
 
 20 
 
 1.00160 
 
 1.00232 
 
 I.0027I 
 
 1.00332 
 
 1.00382 
 
 1.00432 
 
 1.00482 
 
 1.00522 
 
 25 
 
 1.00275 
 
 1.00365 
 
 I.OO4I5 
 
 1.00475 
 
 1.00535 
 
 1.00595 
 
 1.00650 
 
 1.00695 
 
 30 
 
 1.00415 
 
 1.00508 
 
 1.00568 
 
 1.00638 
 
 1.00698 
 
 1.00768 
 
 1.00823 
 
 1.00878 
 
 35 
 
 1-00575 
 
 1. 0068 1 
 
 I.0074I 
 
 i. 008 1 1 
 
 1.00881 
 
 1.00951 
 
 I.OIOII 
 
 1.01071 
 
 40 
 
 1.00755 
 
 1.00864 
 
 1.00934 
 
 1.01014 
 
 1.01084 
 
 .OH55 
 
 I.OI22O 
 
 1.01280 
 
 45 
 
 1.00955 
 
 1.01077 
 
 I.OH53 
 
 1.01228 
 
 1.01308 
 
 .01378 
 
 I.OI443 
 
 1.01503 
 
 5o 
 
 1.01175 
 
 1.01301 
 
 I.OI38I 
 
 1.01461 
 
 1.01541 
 
 .01616 
 
 1.01676 
 
 1.01737 
 
 55 
 
 1.01415 
 
 1.01544 
 
 I.OI624 
 
 1.01704 
 
 1.01785 
 
 .01865 
 
 I.OI925 
 
 1.01980 
 
 60 
 
 1.01675 
 
 1.01808 
 
 I.OI878 
 
 1.01958 
 
 1.02038 
 
 .02118 
 
 1.02160 
 
 1.02233 
 
 65 
 
 1.01955 
 
 1.02081 
 
 I.02I4I 
 
 1.02232 
 
 1.02302 
 
 .02382 
 
 1.02447 
 
 1.02497 
 
 70 
 
 1,02255 
 
 1.02365 
 
 1.02425 
 
 1.02515 
 
 1.02575 
 
 .02655 
 
 1.02721 
 
 1.02771 
 
 75 
 
 1.02570 
 
 i .02669 
 
 I.027I9 
 
 1.02809 
 
 1.02869 
 
 .02939 
 
 1.03004 
 
 1.03054 
 
 80 
 
 1.02900 
 
 1.02973 
 
 1.03033 
 
 1.03113 
 
 1.03183 
 
 1.03243 
 
 1.03303 
 
 1.03348 
 
 85 
 
 1.03240 
 
 1.03307 
 
 1.03367 
 
 1-03437 
 
 1-03517 
 
 1.03567 
 
 1.03017 
 
 1.03657 
 
 90 
 
 1.03585 
 
 1.03661 
 
 I.0372I 
 
 1.03781 
 
 1.03861 
 
 1.03911 
 
 1-03951 
 
 1.03976 
 
 95 
 
 1.03930 
 
 1.04035 
 
 1.04085 
 
 1.04145 
 
 1.04215 
 
 1.04255 
 
 1.04286 
 
 1.04311 
 
 IOO 
 
 1.04275 
 
 1.04409 
 
 1.04459 
 
 1.04520 
 
 1.04570 
 
 1.04600 
 
 1.04630 
 
 1.04660 
 
 TEMP 
 
 C. 
 
 40% 
 
 45% 
 
 50% 
 
 55% 
 
 60% 
 
 65% 
 
 70% 
 
 75% 
 
 
 
 1. 00000 
 
 1. 00000 
 
 I.OOOOO 
 
 I.OOOOO 
 
 I.OOOOO 
 
 I.OOOOO 
 
 I.OOOOO 
 
 I.OOOOO 
 
 5 
 
 1.00113 
 
 1.00133 
 
 1.00153 
 
 1.00163 
 
 1.00173 
 
 1.00173 
 
 1.00178 
 
 1.00183 
 
 10 
 
 1.00246 
 
 1.00276 
 
 1.00306 
 
 1.00326 
 
 1.00341 
 
 1.00351 
 
 1.00356 
 
 1.00366 
 
 15 
 
 1.00399 
 
 1.00434 
 
 1.00469 
 
 1.00494 
 
 1.00514 
 
 1.00529 
 
 1.00539 
 
 1.00549 
 
 17.5 
 
 1.00480 
 
 1.00515 
 
 1.00550 
 
 1.00581 
 
 1.00606 
 
 1. 00616 
 
 1.00626 
 
 1.00641 
 
 20 
 
 1.00562 
 
 1.00602 
 
 1.00642 
 
 1.00667 
 
 1.00692 
 
 1.00712 
 
 1.00722 
 
 1.00732 
 
 25 
 
 1.00735 
 
 1.00785 
 
 1.00825 
 
 1.00850 
 
 1.00800 
 
 1.00895 
 
 1.00905 
 
 1.00920 
 
 30 
 
 1.00918 
 
 1.00978 
 
 1.01018 
 
 1.01043 
 
 1.01073 
 
 1.01098 
 
 1.01093 
 
 1.01113 
 
 35 
 
 1.01116 
 
 1.01182 
 
 I.OI222 
 
 1.01247 
 
 1.01277 
 
 1.01302 
 
 I 01287 
 
 1.01312 
 
 40 
 
 1.01335 
 
 1.01395 
 
 I-OI435 
 
 1.01460 
 
 1.01490 
 
 1.01515 
 
 1.01485 
 
 1.01515 
 
 45 
 
 1.01558 
 
 1.01623 
 
 I.OI658 
 
 1.01683 
 
 1.01713 
 
 1.01728 
 
 1.01688 
 
 1.01728 
 
 50 
 
 1.01791 
 
 1.01862 
 
 I.OI892 
 
 1.01917 
 
 1.01947 
 
 1.01952 
 
 1.01912 
 
 1.01952 
 
 55 
 
 1.02045 
 
 1.02115 
 
 I.02I35 
 
 1.02160 
 
 1.02190 
 
 1.02185 
 
 1.02135 
 
 1.02175 
 
 60 
 
 1.02309 
 
 1.02369 
 
 1.02389 
 
 1.02414 
 
 1.02434 
 
 1.02419 
 
 1.02379 
 
 1.02409 
 
 65 
 
 1.02572 
 
 1.02632 
 
 1.02642 
 
 1.02667 
 
 1.02687 
 
 1.02662 
 
 1.02622 
 
 1.02642 
 
 70 
 
 1.02846 
 
 1.02906 
 
 1 .02906 
 
 1.02931 
 
 1.02941 
 
 1.02916 
 
 1.02886 
 
 1.02886 
 
 1 S 
 
 1.03120 
 
 1.03190 
 
 I.03I80 
 
 1.03195 
 
 1.03205 
 
 1.03170 
 
 1.03150 
 
 1.03130 
 
 80 
 
 1.03403 
 
 1.03484 
 
 1.03464 
 
 1.03469 
 
 1.03479 
 
 L03434 
 
 1.03419 
 
 1.03383 
 
 85 
 
 1.03697 
 
 1.03788 
 
 L03758 
 
 1 -03743 
 
 1.03763 
 
 1.03707 
 
 1.03687 
 
 1.03647 
 
 90 
 
 1.04007 
 
 1.04092 
 
 1.04062 
 
 1.04032 
 
 1.04052 
 
 1.03991 
 
 1.03961 
 
 1.03911 
 
 95 
 
 I -433 I 
 
 1.04406 
 
 1.04376 
 
 1.04336 
 
 1.04346 
 
 1.04276 
 
 1.04256 
 
 1.04185 
 
 IOO 
 
 1.04670 
 
 1.04720 
 
 I.O47OO 
 
 1.04640 
 
 1.04650 
 
 1.04570 
 
 1.04550 
 
 1.04459 
 
312 
 
 TABLES 
 
 -TABLES FOR CALCULATING THE PER CENT OF INVERT 
 SUGAR IN PRESENCE OF SUCROSE FROM THE COPPE 
 PRECIPITATED IN HERZFELD'S REDUCTION METHOD BY 
 10 GRAMS OF SAMPLE 
 
 A. When less than one per cent of invert sugar is in sample. 
 
 
 
 MG. COPPER 
 
 PER CENT 
 INVERT SUGAR 
 
 MG. COPPER 
 
 PER CENT 
 INVERT SUGAR 
 
 
 .05 
 
 155 
 
 59 
 
 65 
 
 .07 
 .09 
 .11 
 
 160 
 165 
 170 
 
 
 
 70 
 
 75 
 g o 
 
 14 
 .16 
 
 175 
 180 
 
 185 
 
 i 
 
 85 
 9 
 
 .21 
 .24 
 
 190 
 195 
 
 79 
 .82 
 
 95 
 
 100 
 
 .27 
 
 3 
 
 02 
 
 200 
 205 
 2IO 
 
 [90 
 
 no 
 "5 
 
 120 
 125 
 130 
 135 
 140 
 
 35 
 .38 
 .40 
 
 43 
 45 
 48 
 
 215 
 220 
 225 
 230 
 
 235 
 240 
 
 245 
 
 93 
 .96 
 99 
 
 1.02 
 1.05 
 1.07 
 1. 10 
 
 145 
 
 53 
 
 
 
 15 
 
 .56 
 
 
 
TABLES 
 
 313 
 
 B. Invert sugar factors when more than one per cent of invert sugar is 
 
 in sample. 
 
 RATIO OF SUCROSE 
 TO INVERT SUGAR 
 
 APPROXIMATE WEIGHT OF INVERT SUGAR CORRESPONDING TO THE 
 
 COPPER ACTUALLY WEIGHED lz) 
 
 R : Y 
 
 200 mg. 
 
 175 mg- 
 
 150 mg. 
 
 125 mg. 
 
 100 mg. 
 
 75 mg. 
 
 50 mg. 
 
 ICO 
 
 56.4 
 
 55-4 
 
 54-5 
 
 53-8 
 
 53-2 
 
 53-0 
 
 53-o 
 
 10 90 
 
 56.3 
 
 55-3 
 
 54-4 
 
 53-8 
 
 53-2 
 
 52-9 
 
 52-9 
 
 20 80 
 
 56.2 
 
 55-2 
 
 54-3 
 
 53-7 
 
 53-2 
 
 52-7 
 
 52.7 
 
 30 7 
 
 56.1 
 
 55-i 
 
 54-2 
 
 53-7 
 
 53-2 
 
 52.6 
 
 52.6 
 
 40 60 
 
 55-9 
 
 55-0 
 
 54-i 
 
 53-6 
 
 53-i 
 
 52.5 
 
 52.4 
 
 5 5 
 
 55-7 
 
 54-9 
 
 54- 
 
 53-5 
 
 53-i 
 
 52.3 
 
 52.2 
 
 60 40 
 
 55-6 
 
 54-7 
 
 533 
 
 53-2 
 
 528 
 
 52.1 
 
 519 
 
 70 30 
 
 55-5 
 
 54-5 
 
 53-5 
 
 52-9 
 
 52-5 
 
 5i-9 
 
 51.6 
 
 80 20 
 
 55-4 
 
 54-3 
 
 53-3 
 
 52.7 
 
 52.2 
 
 5i-7 
 
 5i-3 
 
 90 10 
 
 54-6 
 
 53-6 
 
 53-i 
 
 52-6 
 
 52 i 
 
 5i-6 
 
 51.2 
 
 91 9 
 
 54-i 
 
 53-6 
 
 52.6 
 
 52.1 
 
 51.6 
 
 51-2 
 
 50.7 
 
 92 8 
 
 53-6 
 
 53-i 
 
 52.1 
 
 51.6 
 
 51-2 
 
 50-7 
 
 50.3 
 
 93 7 
 
 53-6 
 
 53-i 
 
 52-1 
 
 51.2 
 
 5i-7 
 
 50-3 
 
 49-8 
 
 94 6 
 
 53-i 
 
 52.6 
 
 51.6 
 
 5o-7 
 
 503 
 
 49-8 
 
 48.9 
 
 95 5 
 
 52 6 
 
 52.1 
 
 51.2 
 
 50-3 
 
 49-4 
 
 48.9 
 
 48.5 
 
 96 4 
 
 52.1 
 
 51.2 
 
 50-7 
 
 49-3 
 
 48.9 
 
 47-7 
 
 46.9 
 
 97 3 
 
 5o-7 
 
 5o-3 
 
 49-8 
 
 48.9 
 
 47 7 
 
 46.2 
 
 45- 1 
 
 98 2 
 
 49-9 
 
 48.9 
 
 48.5 
 
 47-3 
 
 45 8 
 
 43-3 
 
 40.0 
 
 99 i 
 
 47-7 
 
 47-3 
 
 46.5 
 
 45-i 
 
 43-3 
 
 41.1 
 
 38.1 
 
 Explanation of Table B. The cupric-reducing power of an invert sugar 
 solution is not only dependent on the concentration of the invert sugar itself, 
 but is also affected by the amount of sucrose present. Hence, in order to deter- 
 mine the factor for calculating the exact weight of invert sugar corresponding to 
 the copper precipitated, it is necessary to have a convenient way of making a 
 rough preliminary estimation of the invert sugar weight, so that the approxi- 
 mate ratio of the invert sugar to sucrose may be known. 
 
 The approximate weight of invert sugar (Z) is one half of the precipitated 
 copper (Cu). The weight of invert sugar so found, divided by the weight of 
 sample ( W} in 50 cc. of the solution taken for Fehlingtest, is the approximate 
 per cent of invert sugar (i) in the sample. The polarization of the sample 
 (P) is taken as the per cent of sucrose. The ratio of the per cents of sucrose 
 and invert sugar so found is expressed in parts per hundred of the sum of 
 these percentages, and the nearest corresponding ratio (A': Y) is found in the 
 left-hand column of Table B. The factor (F) in this table corresponding to 
 this ratio, in the column under the weight approximating most nearly to the 
 weight of invert sugar (Z), is multiplied by the weight of copper (Cu) to give 
 the exact per cent of invert sugar (/) in the sample. 
 
 Expressed algebraically : 
 
 y CU 100 Z 
 
 t= 
 
 FCu 
 
 W 
 
314 TABLES 
 
 OPTICAL ROTATION CONSTANTS FREQUENTLY USED 
 
 Sucrose, [o]^ = 66.67 "" -9S w (> 4-5 to 22.7). 
 
 (When w is taken as the weight of sugar in grams in 100 Mohr cc., the 
 equation becomes [a] 17 - 5 = 66.82 .0096 w. This of course is not the 
 
 true specific rotation, but is a convenient constant for saccharimetnc 
 calculations.) 
 
 Temperature formula : [a^] = [a]^ .0114 (/ 20). 
 
 Lactose, [a] 20 = 52.53. (Veiy slight change with variation in concentra- 
 tion.) Temperature formula: [a]* = [a] 20 .070(20 f). 
 Maltose, [a] = 140.375 .oi837/ .095 /. 
 Raffinose. [a] 2 ^ = 104.5. 
 Dextrose, [a] 17 = 52.50 + .01 8796^ + .00051683/20 (Little affected by 
 
 temperature change.) 
 Invert sugar, [a]^ = 19.82 .04 /. [a]^ = 27.9 -f- .32*. 
 
 Quartz, [a]* = 21.72 (i + .000143 (20 /)). 
 
INDEX 
 
 Absolute specific rotation, 245. 
 Accuracy of saccharimetry, 39. 
 Acid hydrolysis, lactose, 102; laws, 198, 
 
 252; maltose, 102; raffinose, 108 ; 
 
 speed, 252; starch, 174; sucrose, 103 j 
 
 temperature influence, 254. 
 Acidity, juice, 122. 
 
 Afifinity constants, 251 ; by starch hydrol- 
 ysis, 255 ; by sucrose hydrolysis, 252. 
 Alkaloids, 262 ; brucine, 248 ; chinchoni- 
 
 dine, 264 ; cocaine, 265 ; nicotine, 266 ; 
 
 quinine, 264 ; strychnine, 248 ; used in 
 
 synthesis, 243. 
 
 Alumina, mixture for clarifying, 90. 
 Analyzer, 8. 
 
 Andrews's temperature corrections, 43. 
 Angular degree scales, n, 29. 
 Antipodes, 239 ; separation of, 243. 
 Apparent quotient of purity, 153. 
 Arabinose, 251. 
 Ash, determination in beet juices, 150; 
 
 glucose, 193; density correction, 194. 
 Asparagine in cane juice, 125. 
 Assymmetric carbon, 240. 
 
 Bagasse, 114; fibre in, 124. 
 
 Bag filters, 156. 
 
 Balance, 39, 53 ; specific gravity, 186. 
 
 Barrel sirup, 157. 
 
 Basic lead acetate solution, 54. 
 
 Beaume hydrometers, 128; for glucose 
 industry, 208 ; table, 285. 
 
 Beet juice, 146; diffusion, 145. 
 
 Beet molasses, 148 ; sugar from, 148. 
 
 Beet sugar, 147; export, in, 155; valua- 
 tion, 155. 
 
 Beets, 144; sugar determination, 149; 
 
 sampling, 149. 
 Bibliography, reference books, 279; 
 
 papers on saccharimetry, 100; papers 
 
 on starch, 221. 
 Biose sugars, 101. 
 
 Biot, 17 ; light wave value, 19 ; solution 
 formulae, 245. 
 
 Boiling blank, 135. 
 
 Bone black, 157 ; in saccharimetry, 91 ; 
 filters, 156- spent ("spent black"), 
 158, 207. 
 
 Borneol, 269. 
 
 British gum, 219. 
 
 Brix hydrometers (spindles), 117; con- 
 venient size, 55; reading, 118; tem- 
 perature corrections, 55, 295; tables, 
 285 ; in glucose analysis, 194. 
 
 Brown's researches in starch, 174, 192, 
 199, 221. 
 
 Brucine salts, 248. 
 
 Cadinene, 268. 
 
 Calc spar (see Iceland spar). 
 
 Calculation of errors, 39, 63. 
 
 Calibration of flasks, Mohr cc., 56; true 
 cc., 57. 
 
 Calibration of saccharimeters, 41, 45. 
 
 Camphene, 267. 
 
 Camphor, 247, 270 ; in celluloid, 261. 
 
 Cane culture, 112; fibre, 114; fibre deter- 
 mination, 124; mills, 114; sampling, 
 113; seedling, 112; sour, 123; valua- 
 tion, 113. 
 
 Cane juice, 114; classification, 125; com- 
 position, 115 ; extraction, 115, 123, 139 ; 
 unripe, 122, 140. 
 
 Carbonatation, 146. 
 
 Carvone, 270. 
 
 Caryophyllene, 268. 
 
 Celluloid, camphor in, 261. 
 
 Cellulose hydrolysis, 235. 
 
 Centrifugal machines, 132, 133, 147, 156, 
 
 208. 
 
 Centrifugal sugars, 88, 155. 
 Chandler and Ricketts's detection 
 
 glucose, 226. 
 Citral, 272. 
 
 315 
 
 of 
 
INDEX 
 
 Citronellal, 270. 
 
 Citronellol, 268. 
 
 Clarification, beet juice, 146 ; cane juice, 
 125; Deming process, 126; errors, 96; 
 glucose, 206 ; in saccharimetry, 89, 90 ; 
 Horn's, 90. 
 
 Clarifier (see defecator). 
 
 Clerget method, principles, 104 ; original, 
 105 ; Herzfeid's, 107 ; Tolman's inves- 
 tigation, 108 ; applied by Leach, 232. 
 
 Cocaine, 265. 
 
 Concentration, formulas, 12, 13 ; errors 
 in saccharimetry, 98 ; influence on rota- 
 tion, 5, IT, 244 ; juices, 128 ; glucose, 208. 
 
 Confectionery analysis, 228. 
 
 Constants of rotation, 12. 
 
 Control-tube, 41 ; manipulation, 94. 
 
 Corn for starch manufacture, 212. 
 
 Creatinin in urine, 236. 
 
 Creydt's rafrinose method, 109; modifi- 
 cations, 109. 
 
 Crystallization, in vacuum pans, 130; 
 effect on rotation, i ; in wagons, 135. 
 
 Crystallizers, 135. 
 
 Crusher, cane, 114. 
 
 Cubic centimeter, Mohr, 30, 40, 56, 58 ; 
 true, 30, 40, 46, 57, 58. 
 
 Cupric-reducing power, 172; determi- 
 nation, 196; relation to rotation, 183; 
 table for acid-hydrolized starch, 307. 
 
 Cupric-reduction table, Defren's, 304. 
 
 Defecation (see clarification). 
 
 Defecator, 125 ; tallies, 142. 
 
 Defren, 169, 171, 200; Periling method, 
 169 ; reduction table, 304. 
 
 Deming process, 127. 
 
 Density, 186; by Brix spindle, 118, 120; 
 by pyknometer, 189; table for sugar 
 solutions, 285 ; by Westphal balance, 
 186; of water, 310; factors for starch 
 products, 185 ; factors, assumed, 185, 
 191. 
 
 Dextrose, 102, 109, 174, 175, 176, 179, 180; 
 commercial, 208 ; from rafnnose, 109 ; 
 from sucrose, 102; from starch, 174; 
 multirotation, 249, 251; specific rota- 
 tion, 237, 314; standard solution, 163; 
 table for Fehling determination, 304; 
 table for determination in hydrolyzed 
 starch, 307. 
 
 Diamyl, i. 
 
 Diastase hydrolysis, 174, 183 ; speed, 257, 
 
 Diffusion, 145. 
 
 Doolittle torsion viscosimeter, 215. 
 
 Double dilution, 97. 
 
 Double polarization (see Clerget). 
 
 Double refraction, 2; calc spar, 2; 
 quartz, 22; glass, 2, 42. 
 
 Double-wedge saccharimeter, 37; ma- 
 nipulation, 86. 
 
 Drying of saccharine products, 152. 
 
 Eccentricity errors, 40. 
 
 End-point device, 16; Jellet-Cornu 
 (Duboscq), 19; Laurent, 22; Lip- 
 pich, 25 ; Mitscherlich, 15 ; transition 
 tint, 16; triple-shade, 78; Wild, 26, 73. 
 
 End-point observations, 59. 
 
 Entrainment, 133. 
 
 Enzym action, 102, 174. 
 
 Errors, 63; clarification, 55; concentra- 
 tion, 99; cover glass, 42 ; eccentricity, 
 40; observation, 42; of saccharimetry, 
 38, 96; temperature, 43; tube-length, 
 39 ; volume, 39 ; weighing, 39 ; zero, 
 42, 44. 
 
 Essential (ethereal) oils, 267 ; terpene- 
 less, 272. 
 
 Extraction, juice, 115, 139. 
 
 Extraordinary ray, 3. 
 
 Fehling method, 160; gravimetric, 166; 
 Defren's, 169 ; Herzfeid's, 167 ; Pavy's, 
 165; volumetric, 161. 
 
 Fehling solution, 161 ; Soxhlet's, 161. 
 
 Fenchone, 270. 
 
 Fermentation in sugarhouse, 140. 
 
 Fibre in cane, 114. 
 
 Filar micrometer, 71. 
 
 Filter cake, weight, 128, 138 ; sugar in, 
 127. 
 
 Filter press, 127. 
 
 Filtering solutions, 58. 
 
 Filter, ray, Lippich, n, 72, 259; bi- 
 chromate, 73, 77, 99; brown glass, 78, 
 
 99, 
 
 Fischer's sugar synthesis, 2, 240, 244. 
 Flasks, 46, 54; calibration, 56. 
 Fluidity of starches, 215. 
 Fondants, 229. 
 Fric's saccharimeter, 37. 
 
INDEX 
 
 317 
 
 Galactose, 102, 251. 
 
 Gallotannic acid, 273. 
 
 Gauges, recording, 143. 
 
 Gauging tanks, 141. 
 
 Gill's oleine test, 273. 
 
 Glucose, commercial, 200; clarification, 
 206; colorations, 209; composition, 
 201; concentration, 208; determina- 
 tion, 192, 197, 226 ; dispersive effects, 
 
 77, 106; dyed, 209; in candy, 229; in 
 preserves, 232 ; Japanese, 211 ; loss in 
 manufacture, 212; trade forms, 201; 
 polarization correction, 107. 
 
 Gommelin, 220. 
 
 Graduations, polariscope, n, 60, 71 ; 
 saccharimeter, 28, 29, 35, 46, 47, 60, 
 
 78, 100, 259. 
 Granulator, 147. 
 
 Grape sugar, 200; trade forms, 208. 
 Gumdrops, 229. 
 
 Half-shadow device, 19; sensitiveness, 
 21 (see also end point) . 
 
 Heron (see Brown). 
 
 Herschel's law, i. 
 
 Herzfeld's double polarization, 107; in- 
 vert sugar method, 167; normal 
 weight, 46. 
 
 Honey, 225. 
 
 Home's clarification, 90. 
 
 Hortvet's maple sugar test, 228. 
 
 Hot room, 135. 
 
 Hydrolysis, 102; lactose, 102; maltose, 
 102, 255; speed, 251; starch, 174, 255, 
 257 ; sucrose, 102, 103 ; temperature 
 effect, 254. 
 
 Hydrometers, Beaume, 128; Brix, 117; 
 method of reading, 118. 
 
 Iceland spar (calc spar), 2, 26, 49. 
 
 Intensity of light in Nicol, 8; effect of 
 sugar solution, 9. 
 
 International Sugar Commission, 45, 
 46. 
 
 Inversion, 103 (see also hydrolysis). 
 
 Invert sugar, 103; determination by 
 polarization, 108; reduction method, 
 167; in cane juices, 103; specific 
 rotation, 314; standard solution, 
 164. 
 
 Iodine tests in starch hydrolysis, 176. 
 
 Jaggery, 155. 
 
 Japanese glucose, 211. 
 
 Jellet-Cornu prism, 19. 
 
 Jellies, 232. 
 
 Juice, beet, 146; cane, 114; clarifying 
 cane, 125 ; clarifying beet, 146 ; diffu- 
 sion, 145; extraction, 115; filter press, 
 127; sampling, 124, 141; scums, 127 ; 
 unripe cane, 122, 140; weight deter- 
 mination, 138. 
 
 Jujube paste, 229. 
 
 Kenricks' tartrates method, 273. 
 
 Lactose (see milk sugar) , 222. 
 
 Lamps, for saccharimeters, 52 ; acetylene, 
 52; electric, 52; gas, 52; kerosene, 
 52; Welsbach, 52. 
 
 Lamps, polariscope (sodium), 13, 50; 
 Landolt, 50; Laurent, 50, 68; new 
 form, 51 ; Wiley, 50. 
 
 Landolt, 2, 19, 25, 32, 36, 262. 
 
 Landolt-Lippich polariscope (see Lip- 
 pich). 
 
 Laurent's polariscope, 22; manipulation, 
 68 ; normal weight, 30. 
 
 Leach's methods, 226, 232. 
 
 Le Bel (see Van't Hoff). 
 
 Lemon oil, 271 ; variations, 271 ; adul- 
 terants, 271, 272; terpeneless, 272. 
 
 Levulose, determination, 227; from raf- 
 finose, 108 ; sucrose, 103 ; multi- 
 rotation, 251 ; specific rotation, 226. 
 
 Light, beam, 6; color, 6; complementary, 
 10 ; compound, 7, 9; of D line, n, 30; 
 homogeneous (monochromatic), 7, 9; 
 intensity, 4, 8, 30; mean yellow, 18 ; 
 optical centre, 30 ; optically pure, 30 ; 
 plane of polarization, 7 ; plane polar- 
 ized, 4, 8; plane of vibration, 7; re- 
 fraction, 22 ; ray, 6 ; rotary dispersion, 
 17, 32; rotation, 9; sodium, 9; total 
 extinction, 9 ; undulatory theory, 5 ; 
 waves (vibrations) , 6 ; white, 9. 
 
 Light factor, 258. 
 
 Light filter (see ray filter). 
 
 Limonene, 268. 
 
 Linalool, 268. 
 
 Lippich polariscope, 25, 73; manipula* 
 tion, 71. 
 
 Lippich ray filter, 11,72, 259. 
 
INDEX 
 
 Losses in manufacture, cane sugar, 139 ; 
 chemical, 140; beet, 151; mechanical, 
 140; milk sugar, 223; refinery, 159. 
 
 Maceration, 115 ; determination percent- 
 age, 123. 
 
 Malt preparations, 197. 
 
 Maltose, 102; by acid hydrolysis, 175, 
 199 ; by diastase hydrolysis, 174, 199 ; 
 hydrolysis, 102, 175; in glucose, 192; 
 determination with lactose, 224; spe- 
 cific rotation, 314; table for Fehling 
 determination, 304; table for starch 
 hydrolysis, 307. 
 
 Maple sugar, 227. 
 
 Massecuite, 132. 
 
 Mean yellow light, 17. 
 
 Mechanical filter, 146. 
 
 Meladura, 128. 
 
 Melter, 156. 
 
 Menthol, 269. 
 
 Menthone, 271. 
 
 Midzu-ame, 211. 
 
 Milk sugar, 222; manufacture, 223; de- 
 termination, 224; separation from 
 maltose, 224. 
 
 Millar (see Brown). 
 
 Milliliter, 39. 
 
 Mills, cane, 114. 
 
 Mitscherlich's polariscope, 15. 
 
 Mohr cubic centimeter, 40, 56, 58. 
 
 Moisture in raw sugars, 88, 152. 
 
 Molasses, beet, 148; cane, 101, 103; 
 drying, 152, 153; firs', 134; second, 
 139; sugars (second sugars), 135. 
 
 Molecular rotation, 249. 
 
 Montgolfier's yellow light, 19. 
 
 Morris (see Brown). 
 
 Multirotation, 249. 
 
 Muscovado sugar, 87, 129. 
 
 Neutralize!-, 205. 
 
 Neutralizing, glucose manufacture, 
 
 205. 
 Nicol prism, 3; cleaning 48 ; crossed, 4; 
 
 effect on light intensity, 4 ; " half," 78 ; 
 
 parallel, 4. 
 Nicotine, determination, 266; specific 
 
 rotation, 247. 
 Normal weight, 29; dextrose, 231; 
 
 Duboscq, 31 ; lactose, 224 ; Laurent, 30 ; 
 
 United States standard, 46; Ventzke, 
 35, 46; Wild, 31; 
 Note taking, 64 ; blanks, 65. 
 
 Open kettle sugar, 87, 129. 
 Opposite phase, 6. 
 Optic axis, 2. 
 Optical analysis, i. 
 Optical centre, 30. 
 Optical isomerism, 238. 
 Optically active bodies, i, 10. 
 Optically pure light, 30.^ , 
 Ordinary ray, 3. 
 Osmose process, 148. 
 O'Sullivan, 221; density factor, 185; 
 Fehling method, 169. 
 
 Pasteur's researches, i. 
 
 Pentoses, 235, 240, 251. 
 
 Pinene, 267. 
 
 Plane of polarization, 7. 
 
 Plane of vibration, 7. 
 
 Plane polarized light, 4, 8. 
 
 Polariscope, 5 ; care, 48 ; Duboscq 
 (rotatometer), 19; essential parts, 14; 
 Landolt-Lippich, 25; manipulation, 
 71 ; Laurent, 22 ; manipulation, 68 ; 
 Mitscherlich, 15; transition-tint (Robi- 
 quet), 18; Wild (polaristrobometer), 
 26, 31 ; manipulation, 7. 
 
 Polariscope tubes, 15, 39 ; commercial 
 type, 43 ; control tube, 41 ; control-tube 
 manipulation, 94; for inversion, 93; 
 jacketed, 93;- Landolt's, 43, 92; Lau- 
 rent, 43, 92; Pellet's, 94. 
 
 Polaristrobometer (see Wild polari- 
 scope). , 
 
 Polarizer, 8. 
 
 Polarization formulae, 12. 
 
 Polarization of commercial sugars, 87. 
 
 Preserves, 232. 
 
 Prisms, Jellet-Cornu, 19; Nicol, 3. 
 
 Pulegone, 271. 
 
 Purity (see quotient of purity) . 
 
 Pyknometer, 189. 
 
 Quartz, rotation, i, 16; rotary dispersion, 
 17,32; specific rotation, 30; tempera- 
 ture effect on rotation, 45. 
 
 Quartz plates, for standardizing, 45; 
 Laurent half-shade, 23; standard, 41 ; 
 transition-tint, 17. 
 
INDEX 
 
 319 
 
 Quartz-wedge compensator, 32 ; double, 
 36 ; Martens's, 36. 
 
 Quinine, 262. 
 
 Quotient of purity ,"116; apparent, 153; 
 beet products, 153; refinery method, 
 120; Weisberg's method, 121. 
 
 Racemic acid, 241. 
 
 Racemic compounds, 238 ; resolution, 
 243 ; symbolized, 240. 
 
 Radiator, 170. 
 
 Raffinose, 108 ; determination, 108 ; 
 hydrolysis, 109 ; occurrence, 108, 149. 
 
 Raw sugars, 155 ; sampling, 85. 
 
 Ray filter, bichromate, 73, 77 ; brown 
 glass, 78 ; Lippich, 72, 73. 
 
 Recording gauges, 143. 
 
 Refinery losses, 159. 
 
 Refinery methods, 155. 
 
 Rotation, absolute specific, 245 ; funda- 
 mental laws, 10 ; relation to molecule, 
 249; specific, n, 19; standard tem- 
 perature, 13; very accurate determina- 
 tions, 13. 
 
 Rotatory power, specific, n. 
 
 Saccharimeter, 28 ; care, 48 ; double- 
 wedge, 37, 86 ; Duboscq, 30, 31 ; 
 errors, 39 ; Fric, 37 ; half-shade (see 
 Schmidt and Hansch) ; installation, 
 48 ; Laurent, 30, 68 ; light factor, 258 ; 
 Peters, 36 ; quartz-wedge, 31 ; Schmidt 
 and Hansch, 35; Soleil-Duboscq, 33, 
 85; Soleil-Ventzke-Scheibler, 34, 83; 
 standardizing, 41,45,46; triple-shade, 
 
 36, 78; United States standard, 46; 
 Wild, 26, 31, 73. 
 
 Saccharimeter scales, illumination, 35, 
 
 37, 48, 60; ivory, 36; nickelin, 36; on 
 quartz, 37. 
 
 Saccharimeter graduation, 28, 29, 31, 35, 
 46, 47, 60, 78, 100, 259. 
 
 Saline coefficient, 151; cane, 113. 
 
 Sampling juice, 124 ; molasses, 88 ; raw 
 sugar, 87; in sugarhouse, 141. 
 
 Scales, illumination, 35, 37, 48, 60 ; polari- 
 scope, n, 60, 71 ; readings, 60, 69, 71, 86 ; 
 Saccharimeter, 28, 36, 37 ; vernier, 61. 
 
 Scheibler, double dilution, 97 ; improve- 
 ments on saccharimeters, 34; mois- 
 ture in starch, 216; ash method, 151. 
 
 .Second grain, 132. . . 
 
 Seedling cane, 112. 
 
 Seed selection of beets, 144. 
 
 Sensitive tint, 33, 83. 
 
 Shredder, 114. 
 
 Size compounds, 218. 
 
 Sodium light, 9, n, 30; filtered, n; op- 
 tical centre, n ; spectrally purified, n ; 
 wave length, n (see lamps). 
 
 Solvent, effect on rotation, 12, 245. >- 
 
 Soxhlet tube, 169. 
 
 Soxhlet, Fehling solution, 161. 
 
 Special laboratory apparatus, 54. 
 
 Specific gravity, 186; by Brix spindle, 
 118 ; calculations, 190 , factors, 185, 191 ; 
 by pyknometer, 189 ; by Wesphal bal- 
 ance, 186. 
 
 Specific rotatory power, n, 19; absolute, 
 245 ; effect of salts, etc., 247 ; formulae, 
 12; molecular, 249; solvent effect, 12, 
 244; table, 314; temperature effect, 12, 
 247 ; very accurate determinations, 
 
 13- 
 
 Speed of hydrolysis, 252, 254. 
 
 Standards, light, u, 19, 30; sacchari- 
 metric, 30, 46. 
 
 Starch, 173; acid, 214; alkalai, 214; 
 chemistry, 174 ; corn, 178, 202 ; fluidity 
 (viscosity), 215 ; hydrolysis, 174 ; iodine 
 tests, 176; manufacture, 176, 202 ; mois- 
 ture in, 216; paddling, 213; potato. 
 177 ; thin boiling, 177, 214 ; wheat, 178. 
 
 Starch determinations, 177 ; diastase, 
 180; Hibbard, 181; Sachsse, 180. 
 
 Steffen's molasses process, 149. 
 
 Stock in process, 137; calculation, 
 
 139. 
 Sucrose, chemistry, 101 ; chemically 
 
 pure, 95; inversion (hydrolysis), 103; 
 
 per cent by density (Brix table), 285; 
 
 pipette, 118 ; specific rotation, 314. 
 Sugar, chemistry, 101 ; commercial, 87; 
 
 effect on polarized light, 9; export 
 
 (beet), in, 133; grape, 200; hydrolysis, 
 
 101,251; in urine, 236; multirotation, 
 
 249. 
 
 Sulphites in glucose, 207. 
 Sulphuring, beet juice, 146, 147 ; cane 
 
 juice, 125. 
 Synthetic compounds, inactive, 243; 
 
 made active, 243. 
 
320 
 
 INDEX 
 
 Tables, Brix, 285; Beaume, 285; Brix 
 temperature correction, 295 ; carbo- 
 hydrates of acid-hydrolyzed starch, 
 307; cupric-reducing power of acid- 
 hydrolyzed starch, 307; Defren's 
 copper oxide equivalents, 304 ; density 
 of sugar solutions, 285; density of 
 water, 310; density factors for hydro- 
 lyzed starch, 195 ; Herzfeld's double 
 polarization factors, 107; Herzfeld's 
 Fehiing invert sugar equivalents, 312, 
 313 ; Saare's moisture in starch, 217 ; 
 Schmitz sucrose solution, 296 ; Schmitz 
 saccharimeter correction, 99; volume 
 of sugar solutions, 311; Weisberg's 
 quotient of purity correction, 154. 
 
 Tartaric acid, 241 ; specific rotation, 247, 
 263. 
 
 Tartrates, Kenricks' method, 273. 
 
 Temperature, effect on rotation, n, 45, 
 247 ; effect on hydrolysis, 254 ; errors 
 in saccharimetry, 43; standard for 
 polarizing, 12, 13, 45; standard for 
 starch analysis, 193 ; standard for sugar 
 analysis, 43. 
 
 Terebenthene (see pinene) . 
 
 Terpeneol, 269. 
 
 Terpentine in lemon oil, 271 ; specific 
 rotation, 247. 
 
 Thujone, 270. 
 
 Tol man's double polarization formulae, 
 108. 
 
 Total solids, by drying, 152 ; Brix spindle, 
 116 ; Weisberg's method, 153. 
 
 Transition tint, 17. 
 
 Transition-tint plate, 16. 
 
 Treacle, 157. 
 
 Trier, 88. 
 
 Undulation (see wave). 
 Undulatory theory, 5. 
 Urine, sugar in, 236; creatinin in, 236; 
 polarization, 237. 
 
 Van't Hoff-Le Bel theory, i, 238, 249. 
 Vernier scale, 61 ; method of reading, 
 
 61. 
 Viscosity of cane juices, 122; starches, 
 
 214 ; dextrins, 220. 
 Viscosimeter, 215. 
 
 Water for polarimetry, 55 ; density table, 
 310. 
 
 Wave, 6. 
 
 Wave length, 67; half, 6; sodium light, 
 ii. 
 
 Weber and McPherson, glucose correc- 
 tion, 107. 
 
 Wedge (see quartz wedge). 
 
 Weisberg, purity method, 121 ; correc- 
 tion table, 154. 
 
 Whey, 222. 
 
 White sugar, 125. 
 
 Wiley, double dilution, 97; glucose 
 research, 183 ; lactose clarification, 224 ; 
 levulose determination, 227 ; starch 
 determination, 80; temperature correc- 
 tion, 44. 
 
 Xylose, 235, 251. 
 
 Yellow light, 9; mean, 18, 19. 
 
 Zero error, 42, 44 ; affected by tempera- 
 ture, 44; when ignored, 45. 
 
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