WASON' 
 
 IP 
 
 379 
 
 J4 
 
 P95* 
 
 1906 
 
 ASIA 
 
 ^^^^B* 
 
Cornell University 
 Library 
 
 The original of tiiis book is in 
 tine Cornell University Library. 
 
 There are no known copyright restrictions in 
 the United States on the use of the text. 
 
 http://www.archive.org/details/cu31924009374376 
 
Cornell University Library 
 TP 379.J4P95 1906 
 on cane sugarand the process oU^^ 
 
 3 1924 009 374 376 «m 
 
ON 
 
 CANE SUGAE 
 
 AKD THE 
 
 PIIOCESS OF ITS MANUFACTURE 
 
 IN JAVA. 
 
 BY 
 
 H. C. PRINSEN GEERLIGS, 
 
 Director of the " West -Java " Sugar Experiment Station, 
 Kagok - Pekalongan. 
 
 SECOifD EDITION. Revised and Enlahqed. 
 
 NOfiMAN EODGER, 
 Alteincham. 
 
 1906. 
 
PREFACE TO THE FIRST EDITION. 
 
 It has been suggested to me to put together for publicatiou in a separate form 
 whatever is of importance for the scientific director or superintendent to know 
 respecting the management of a Cane Sugar Factory. Good manuals already 
 exist for methods of analysis and the chemical conti'ol of the working, but 
 hitherto no connected work on the actual manufacture of sugar from cane, as 
 carried on in Java, has appesi-ed. 
 
 This omission was all the more felt, because it was impossible for those who 
 wanted to keep a la hauteur of this class of operations to meet with handbooks 
 relating to it, seeing that all the foreign works on sugar, even when professedly 
 giving a complete resume of the entire industry, only contained — after whole 
 chapters devoted to beet sugar — a few pages relating to the cane sugar industry, 
 in which as a mle the most antiquated and incorrect ideas were put forward. 
 
 In this small work, which is primarily intended for the scientific man or the 
 factory manager, I have only treated of the m^echanical portion so far as is 
 necessary to afford a good idea of the manner of working. With the exception of 
 ■ the crushing plant, the machinery for the preparation of cane sugar varies only in 
 subordinate points from that used in the manufacture of beet sugar, so that all 
 possible indications on this point are to be found in every handbook on beet 
 sugar, and it would be going beyond the scope of this book to include them here. 
 
 In drawing up this introductoiy manual, I have, in addition to my own 
 investigations, been glad to avail myself of the treatises published in the Archief 
 voor de Javasuikerindustrie, by Messrs. C. J. van Lookeren Campagne, B. Carp., 
 and Dr. H. Winter, and I have to thank Mr. J. H. Maronier for assistance in the 
 description of machinery. 
 
 In conclusion, I may remark that I have done my best to give the facts, and 
 to exclude theoretical suppositions as much as possible. 
 
 H. 0. Prinsen Geerligs. 
 
PREFACE TO THE SECOND EDITION. 
 
 As tlie first edition of this little work became rapidly exhausted, a 
 second edition vas thought necessary ; of which opportunity 1 profited to 
 thoroughly revise it and make the changes which were induced by the 
 improvements in sugar manufacture introduced during the last few years. 
 
 So the chapters on "Constituents of the Cane," "Juice Extraction," 
 "Clarification," "Boiling," "After-products,'' and "Molasses," were 
 re-written, causing this treatise to exactly represent the present state of 
 knowledge and manufacture in Java. 
 
 H. C. Prinsen Geerligs. 
 
 Pekalongan, 
 
 1st May, 1902. 
 
TABLE OF CONTENTS. 
 
 PAGE 
 
 Introduction 
 
 PART I. 
 The Raw Materul. 
 
 CHAPTER I. 
 
 The Sugar Cane and its Comtitiients. 
 
 Propagation and Cultivation 3 
 
 Constituents : — 
 
 1. Cane Sugar or Sucrose 4 
 
 2. Dextrose 5 
 
 3. Levulose g 
 
 4. Organic Acids 9 
 
 5. Nitrogenous Bodies 10 
 
 6. Colouring Matter __ 19 
 
 7. Cane Wax 1 1 
 
 8. Pectine U 
 
 9. Fibre u 
 
 10. IncombustiWe Matter or Asi 12 
 
 CHAPTBH II. 
 Distribution of the Constituents in the Cane, 
 
 PART II. 
 
 SUGAK MaNCFACTUKE. 
 
 CHAPTER I. 
 Extraction of the Juice. 
 
 Methods of Extraction 15 
 
 Mills 15 
 
 Cane-cutters, Shi'edders, and Crushers 16 
 
 Maceration 16 
 
 Regulation of the Milling Work 17 
 
 DifEusiou 19 
 
 Advantages and Defects of Milling and Diffusion 21 
 
 CHAPTER II. 
 Composition of the Juice. 
 
VI. CONTENTS. 
 
 CHAPTBR III. 
 Clarification. 
 
 PAGE 
 
 Principles and Expedients 25 
 
 I. — Defecation. 
 
 1. Seating, Liming, Subsiding. 
 
 Estimation of the Quantity of Lime necessary for Clarification 26 
 
 Difficulties met with in Tempering 26 
 
 Defecation Pans 27 
 
 Subsiding 27 
 
 Skimming * 28 
 
 Expedients 28 
 
 Deming's Superheat Clarification 29 
 
 2. Treatment of the Olarified, Juice. 
 
 Elimination 32 
 
 . Neutralization 33 
 
 3. Treatment of the Sewn. 
 
 Steaming and Liming 33 
 
 II. — Carbonatation. 
 
 Principles 33 
 
 Operation 34 
 
 1. Single Carbonatation. 
 
 Liming . . , . 36 
 
 2. Double Carbonatation. 
 
 Method 36 
 
 Liming 36 
 
 Saturation with Sulphurous Acid 36 
 
 Advantages and disadvantages of different methods 37 
 
 III. — Other Clarifying Agents. 
 
 1. Phosphoric Acid 37 
 
 2. Sulphurous Acid 38 
 
 3. HydroBulphurous Acid 38 
 
 4. Soda 39 
 
 6. Barytes 39 
 
 6. Chloride of Calcium, of Aluminia, of Zinc, &c 39 
 
 IV. — Filtration. 
 
 1. Juice Filters 39 
 
 2. Scum Filters 41 
 
COSTENIS. Til. 
 CHAPTER IV. 
 
 Concentration of the Juice. 
 l.—Evaparatxon. ^^^^ 
 
 Copper Wall 42 
 
 Vacuum Apparatus 42 
 
 Triple Effet 43 
 
 Cleaning Vessels 44 
 
 Yaryan Apparatus 45 
 
 II. — Clarification of the Syrup. 
 
 Elimination 45 
 
 Keutialization 46 
 
 Subsiding 46 
 
 Working up of the Scum 46 
 
 III. — Soiling. 
 
 Vacuum Pan 47 
 
 Graining 47 
 
 Constitution of First Masse-cuites, Shape of the Crystals 49 
 
 Dilution of Concentrated Masse-ouite with Molasses 51 
 
 Circulation in the Pan 62 
 
 Boiling Smooth 53 
 
 CHAPTER y. 
 Curing of First Sugar. 
 
 Cooling in Crystallization Cisterns 54 
 
 Crystallization in Movement 65 
 
 Apparatus for the same 56 
 
 Advantages of Crystallization in Movement 56 
 
 Curing 57 
 
 Covering with Water, Steam, or Sugar-Syrup 59 
 
 Drying and Packing 60 
 
 CHAPTER VI. 
 
 After-products. 
 
 Constitution of Molasses, and Solubility of Sugar in the Water of the Molasses .. 61 
 
 Elimination, Skimming and Neutralization 62 
 
 Boiling 64 
 
 Crystallizing 65 
 
 Analyses of Molasses Masse-cuites 65 
 
 Froth Fermentation 66 
 
 Curing 66 
 
 Sack Sugar or Black Syrup 67 
 
 Meltng Second Boilings , . , , , . , . . , . . . , , . , . . 67 
 
VIU. CONTENTS. 
 
 CHAPTBK VII. 
 
 Exhausted Molasses. page 
 
 Formation 69 
 
 Constitution 70 
 
 Use 75 
 
 PART III. 
 
 Chemicals used in Cane SroAE, Manupaceurb. 
 
 I. Lime 78 
 
 Biirning • ■ 76 
 
 Lime-kilns 76 
 
 Slaking 76 
 
 Analysis 77 
 
 II. Phosphoric Acid 78 
 
 Analysis 78 
 
 Preparation 78 
 
 III. Sulphurous Acid 79 
 
 PART IV. 
 
 Tables. 
 
 1. Table and Formula for the Adjusting of the Bagasse Turner for Mills with 
 
 Rollers having a diameter of 26 in. to .32 in 80 
 
 2. Table showing the Solubility of Sucrose in "Water at Temperatures from 0° to 
 
 100° C. (32°— 212° F.) 81 
 
 3. Specific Gravity of Milk of Lime 82 
 
 4. Specific Gravity of Soda Solutions at 28° C 83 
 
 5. Specific Gravity of Solutions of Carbonate of Sodium at 28° C 83 
 
 6. Specific Gravity of Pure Phosphoric Acid Solutions at 28°C 84 
 
 7 . Relation between degrees Celsius and Fahrenheit 85 
 
ON 
 
 CANE SUGAR 
 
 AND THE 
 
 PROCESS OF ITS MANUFACTURE 
 IN JAVA. 
 
 INTEODirCTION. 
 
 The sugar cane, whicli is now cultivated in many varieties in every tropical 
 and semi-tropical countiy of the world on a, larger or smaller scale, came 
 originally, according to De Candolle, from Cochin China or neighbouring lands, 
 from whence it was brought over to China, the islands of the Indian Ocean, India, 
 an-d afterwards to Arabia. In their wars of conquest, the Arabians introduced 
 the cultivation of the sugar cane successively into Persia, Egypt, Palestine, 
 Syria, along the whole north coast of Africa, into Sicily, and into Spain. The 
 Spaniards transported it, after the expeditions of Columbus, to their empire in the 
 West Indies and America, where the cultivation at once became a very flourishing 
 one. Cook found the sugar oane in a cultivated state in the Polynesian islands, 
 to which it had very probably been brought from Asia. 
 
 From the most remote historical times the sugar cane was used in China and 
 in India, as a nutrient or a dainty, the cane itself being eaten or the juice sucked 
 out from it, but no real preparation of sugar is recorded before about 600 A.D., at 
 which period a Chinese emperor sent a man to learn the art of sugar-making in 
 India, in which countiy it was already known at a much earlier period, for 
 in the year, 500 a.d. white sugar is mentioned as being shipped to Europe from 
 India. 
 
 Although in the first 1000 years of our era sugar was imported into Europe, 
 where it was regarded as a rare and precious article, the importation of sugar 
 •from Asiatic countries only assumed large proportions when, as a consequence of 
 the Crusades, the trade between Europe and Western Asia became more con- 
 siderable. Afterwards, when, besides the cane-growing countries already 
 mentioned, the Spanish and Portuguese possessions in America also produced 
 
sugar, the consumption of cane sugar increased more and more, until in the 
 beginning of the 19th century the manufacture of sugar from the beetroot in a 
 practical way was invented in Europe. Since that time the production of cane 
 sugar, though steadily increasing in volume, has been constantly falling behind 
 as compared with that of beet sugar, and while it formerly represented the entire 
 consumption, it now (1905) only amounts to 43^ of the total production coming 
 into consideration for the world's market. 
 
 The keen competition with the beet sugar, which is in these days being 
 grown in nearly all th^ countries of the temperate zone, has, however, had this 
 advantage, that the cane sugar industry, which up to a very short time ago had 
 been conducted in a very irrational and sometimes even reckless maimer, has 
 profited by all the experience and improvements that have proved successful in 
 beet sugar manufacture, has placed on a scientific basis the methods of cultiva- 
 tion and manufacture, and so has succeeded in maintaining itself, though 
 every year with increasing difldoulty, as yet mostly unprotected against the 
 heavily subsidized competing industry. 
 
PART I. 
 
 THE RAW MATERIAL. 
 
 CHAPTER I. 
 
 The Sugar Cane and its Constituents. 
 
 The sugar cane {Saccharum officinarum) is a perennial plant of tlie family of 
 the Gramiaeae. It can be propagated by seed as well as by layers or cuttings, 
 but in practical working only the latter way is used ; the production of cane from 
 seed being only used by scientists or by cane growers with a view to raising new 
 cane varieties by cross-fertilization. After the new varieties are selected those 
 which possess superior qualities are picked out and propagated by cuttings. The 
 upper portions of the cane are almost universally regarded as the best planting 
 material; they are cut into pieces of a foot or more in length, and planted 
 horizontally or with a sKght inclination. After a period of from seven to twenty 
 days, varying according to the variety of the cane, the age of the cuttings, and 
 the temperature, the buds sprout and form a young plant, which soon grows up, 
 forms a stalk and leaves, and also sends out rootlets in the soil. After the stalk 
 has grown up, its undermost buds also sprout and again form stalks, under which 
 process the whole plant assumes the form known under the name of " stool." 
 
 As the canes grow older, the lower leaves dry up and fall off, which process 
 is promoted in cultivation by the stripping or trashing, i.e., removing of the dry 
 leaves. The spot where the leaf is attached to the cane is called the knot, which 
 remains visible as a swollen ring. On the knot is situated the bud or eye, and 
 the part of the cane between two knots is called the joint. As the leaves 
 gradually fall off, the ripe cane assumes the aspect of a long rod, bearing rings, 
 and adorned at the top with a tuft of green leaves. Some canes arrow, others do 
 not, and as yet no one has been able to detect the reason of this difference. 
 Some time after planting, varying, according to the variety of the cane or the 
 climate of the country, between ten and twenty months, the cane contains its 
 maximum of sugar and must be cut. The canes are dug out, or, if it is wished 
 to get ratoons from them, simply out, and deprived of the tops bearing the green 
 leaves, as the top is an excellent planting material, but if crushed along with the 
 canes is more apt to spoil the juice than to enrich it. 
 
 In countries where the planters are owners of the land and labour is scarce, 
 they prefer allowing a second crop to sprout from the stubble remaining after 
 the first harvest, and can get as many as even six successive crops from the same 
 stubble without planting again, though by so doing the crop becomes smaller and 
 smaller every year. In other countries where the area planted is restricted and 
 labour is abundant and cheap, only very little ratoon cane is grown, and, as a 
 
rule, the stubble is dug out after the reaping, and new fields are planted with 
 fresh cuttings. 
 
 Among the varieties of cane planted in the large cane-growing centres, the 
 most conspicuous are : the black cane, the Bourbon, the Lahaina, the transparent 
 cane, the ribbon cane, and many others among the scions of seedling canes 
 deserving special mention. 
 
 The constituents of the sugar cane, other than water, which of course forms 
 the principal part, are as follows : — 
 
 1. Cane Stjgab on Sucrose. 
 
 Cane sugar is found in a great many plants, dissolved in the sap, but only 
 a few of them contain it in such a degree as to allow of its profitable extraction. 
 They are the sugar cane, the beetroot, the sorghum, the sugar, coco, date, 
 palmyra, and nipah palms, and the maple tree, while the bees extract it from 
 the flowers of many plants, but in this case it is, however, very soon converted 
 into glucose. 
 
 Pure sucrose appears under the form of anhydrous, bright, monoclinic 
 crystals, having a pure sweet taste and possessing a specific gravity of 1"58 at , 
 15° 0. Sucrose is freely soluble in water, and its solubility increases as the 
 temperature rises ; the exact figures relating to this will be found in Part IV. 
 It is almost insoluble in absolute alcohol, but dilute alcohol dissolves it and this 
 in proportion as the alcohol is,, more dilute and the temperature higher. Ether, 
 chloroform and other essential liquids, and anhydrous glycerine do not dissolve 
 sucrose. On evaporating a solution of sucrose in water or on cooling a hot 
 saturated solution, sucrose is deposited in crystals, which are larger in proportion 
 as the liquid in which they are formed is purer and the crystallization slower. 
 
 Solutions of cane sugar deflect the plane of the polarized light ray to the 
 right in a degree proportioned to the concentration of the solution and the 
 thickness of the layer of liquid through which the beam passes, this deflection 
 being only slightly altered by changes of temperature. Much use of this 
 property is made in sugar-mill laboratories in the determination of the sugar 
 content of juices, sugars, etc., by means of the polariscope. 
 
 Perfectly dry sucrose may be heated for a long time at temperatures exceed- 
 ing 100° 0. , and even melted at 160° 0. without its undergoing any decomposition ; 
 but in presence of water it is decomposed at temperatui-es above 100° C, as shown 
 by the dark colour it assumes, and the property it has acquired of reducing 
 FehKng's test solution. 
 
 Sucrose, when heated for some time at its melting point, changes without 
 any loss of weight into a mixture of dextrose and levulosan. On heating cane 
 sugar at a still more elevated temperature it loses water and leaves behind a 
 dark coloured body, called caramel. If we fui-ther raise the temperature, this 
 also becomes decomposed into gaseous products and a glossy coal, which on 
 combustion in contact with air totally disappears without leaving anything 
 behind, provided the sucrose has been pure. 
 
On heating sucrose solutions at their boiling point for a long time con- 
 tinuously, the sucrose combines with water even at the ordinary atmospheric 
 pressure, and changes gradually into a mixture of equal parts of dextrose and 
 levulose. Under a higher pressure, coincident with a higher boiling point, this 
 reaction takes place more quickly, so that a sucrose solution, which when boiUng 
 at 100° 0. is totally transformed after a lapse of 24 hours, is already quite 
 changed into the above-mentioned mixture after six hours' heating at 150° 0. 
 During the transformation, 95 parts of sucrose combine with five parts of water 
 to form 100 parts of invert sugar, as the mixture of equal parta of dextrose and 
 levulose is called. The sugar thus transformed now deflects the plane of 
 polarization to the left, instead of to the right, hence the newly-formed body 
 bears the name of invert sugar, and the phenomenon itself that of inversion. 
 When sucrose is brought into contact with dilute acids it becomes inverted, 
 slowly at the ordinary temperature, but quickly on heating. 
 
 The action of the different acids varies considerably, and, moreover, they all 
 act much more quickly the more concentrated they are; thus at 70° 0. an addition 
 of 10 per cent, of 30 per cent, hydrochloric acid in a few minutes inverts a 
 solution of sucrose without causing any coloration, which property is often made 
 use of in analysis. 
 
 The inverting power of some acids, used in equivalent quantities at 25° C, 
 on a 50 per cent, sucrose solution may be indicated by the table underneath, 
 where hydrochloric acid is taken as the starting point with the figure 100. 
 
 Hydrochloric acid . . . . 100 
 
 Nitric acid 100 
 
 Sulphuric acid 53'6 
 
 Oxalic acid 18-6 
 
 Phosphoric acid . . . . 6'2 
 
 Tartaric acid 3-1 
 
 Citric acid TT 
 
 Formic acid 1-5 
 
 Malic acid 1'3 
 
 Lactic acid I'l 
 
 Succinic acid 0'5 
 
 Acetic acid 0-4 
 
 Mineral acids, especially at high temperatures, along with inversion 
 produce a stiU further decomposition, which is accompanied by a dark coloration, 
 and in the end causes sucrose to be decomposed into various volatile as well as 
 black fixed acids, the latter being classed together under the name of humic acids, 
 but their composition has as yet been insufficiently investigated. 
 
 Alkaline bodies, such as potash, soda, lime, etc., only attack sucrose solutions 
 when they are heated with them in a concentrated state. At a not too strong 
 concentration they combine with the sucrose and foi-m very soluble alkaline 
 combinations called saccharates, which require just as much acid for their 
 neutralization as the quantity of base present in the combination. In the 
 formation of such a soluble saccharate, lime, which is only slightly soluble in 
 water, dissolves on the contrary freely in a sugar solution. Like all other acids, 
 carbonic acid also decomposes these saccharates. 
 
 Salts also, like bases, may form combinations with sucrose; in this way 
 sucrose-sodium-chloride, sucrose-sodium-iodide, and some others are known to 
 exist in a crystallized form, but all of these are very soon decomposed and are 
 rather uninteresting. 
 
Many salts, principally those of inorganic acids, have the property of invert- 
 ing sugar solutions at their boiling point, -which property seems not to increase in 
 proportion with their concentration. The simultaneous presence of glucose 
 increases this property in proportion as the glucose content rises, so that 
 while in the beginning only very little sugar is inverted, this inversion goes 
 on in a continually higher degree. Not only do salts with an acid reaction show 
 this inverting power, but even alkaline salts, having a neutral reaction, and 
 especially those which, like ammonium salts, are very liable to dissociation, or 
 salts with feeble bases. Salts with a strong base, or salts of organic acids (which 
 even when free are but feeble inverters), accordingly possess also a very slight 
 inverting power or none at all, or wUl even neutralize by their mere presence the 
 action of the other salts. 
 
 Sucrose is very liable to be broken up by all kinds of ferments. Well nigh 
 all the species of yeast separate a ferment that transforms sucrose into invert 
 sugar, which latter afterwards becomes changed by the iniluence of the yeast 
 enzymes into carbonic acid, alcohol, and some by-products, causing the sucrose, 
 as such, to disappear totally. The lactic acid bacteria transform sucrose, especially 
 in presence of lime, into lactic acid, in which process carbonic acid and hydrogen 
 also arise ; and this process is often followed by the butyric acid fermentation, 
 forming the unpleasant smelling butyric acid from the lactic acid, a phenomenon 
 sometimes met with in practical working. Another lower organism, Leuconostoc 
 mesenterioides, wlU, more especially if lime or chalk are present at the same time, 
 convert sucrose, with formation of acids, into a thick, sUmy, tough mass, which 
 appears in gelatinous layers or lumps, and bears the name of dextran. Not only 
 does the sucrose aSeoted become totally lost in this way, but these lumps, by 
 their choking up the pipes and cocks, may cause much trouble in the factory. 
 
 2. Dextrose. 
 
 Dextrose, besides occurring along with levulose as a product of decomposition 
 (due to inversion) in over-ripe canes, is a normal constituent of both ripe and 
 unripe cane, and is therefore to be found in all cane juice to a greater or less 
 extent. It is also a very widely spread constituent of plants in general, and is 
 manufactured commercially in huge quantities by the action of sulphuric acid on 
 starch. 
 
 Anhydrous dextrose appears in the form of hard columnar crystals melting 
 at 146° 0., while the more common hydrate occurs in opaque crystal-crusts or in 
 big transparent crystals with a melting point of 86° 0. 
 
 Dextrose dissolves very easily in water. At 15° C. 100 parts of water dissolve 
 81-68 parts of anhydrous dextrose or 97-85 parts of the hydrate ; in the same way 
 dextrose is soluble in alcohol and this in proportion as the alcohol is warmer and 
 more dilute. This sugar also dissolves m methyl-alcohol, but not in ether or 
 acetone. 
 
 Like sucrose, dextrose deflects the plane of polarization to the right, though 
 in an inferior degree, for if we suppose the rotation of the former equal to 100, 
 that of anhydrous dextrose is equal to 80, and that of the hydrate to about 73, 
 while the specific rotation rises as the concentration of the solution increases. 
 
Variation in temperature does not influence tlie rotatory power within those 
 limits which, are not exceeded in ordinary laboratory work. The above figures do 
 not apply in the case of freshly made cold dextrose solutions, as in this case the 
 dexti'ose has a much greater rotatory power, which may even become twice the 
 value just mentioned. After standing some time cold, or sooner on being heated, 
 or made alkaline with a little ammonia, the rotation diminishes and comes back 
 to the lower figures given above. 
 
 Dextrose, when heated above 100° 0., assumes a brown coloration; at 
 170° 0. water passes ofl, and the coloured residue contains, among other things, 
 dextrosan, while at a stUl more elevated temperature the substance inflates, 
 blackens, and allows a large quantity of gaseous products to escape, the rest being 
 a carbonaceous mass, containing caramel, which, when heated in contact with the 
 air, undergoes total combustion. 
 
 Dilute acids exercise no influence on dextrose, but ^concentrated strong acids 
 break it up just like sucrose, causing formation of black humic combinations. 
 
 Alkalies convert dextrose, especially at an elevated temperature, into a 
 mixture of dextrose, levulose and mannose. This process goes on gradually until 
 the dextrose and the levulose are represented in fairly equal parts, while the 
 quantity of mannose is very small. Even very feeble concentrations of alkalies 
 or alkaline earths have this property. An addition of o grammes of lime to 100 
 grammes of dextrose dissolved in 400 grammes of water is able to change at a 
 temperature of 70° C. the dextrose in the above-mentioned mixture within a few 
 hours. 
 
 Apart from this reaction alkalies and alkaline earths combine with 
 dextrose and form dextrosates, combinations of a character analogous to the 
 saccharates already mentioned. They are, however, very unstable, as the 
 bases act upon the dextrose after standing some time or on the temperature 
 being raised, converting it into acids and combining with these, forming salts. 
 The products of decomposition formed by this reaction differ according to the 
 concentration, the temperature, and the nature of the alkali. At temperatures 
 ujider 60°C. the products caused by the decomposition of dextrose are principally 
 saccharinic and lactic acids, both uncoloured bodies, yielding salts not liable to 
 spontaneous decomposition. Under reaction at high temperature, however, 
 saccharinic, glucinic and melassinic acids and other dark-coloured, scarcely 
 investigated bodies are produced, the colotired salts of which are apt to become 
 broken up spontaneously into acetic, formic, and apoglucinic acids, causing a 
 neutral solution to turn acid. The Hme salt especially of this acid is hygroscopic, 
 and yields a viscous solution ; the solutions of the potash and soda salts of the 
 same acid are much more liquid. Dextrose, in alkaline solution, eagerly absorbs 
 oxygen, both free and combined, hence many metallic oxides, as chloride of gold, 
 nitrate of silver, etc., become reduced by an alkaline dextrose solution. Oupric 
 oxide is reduced to cuprous oxide, and this, if the conditions are always identical, 
 in quantities proportioned to the quantity of dextrose ; this property is made 
 use of in the determination of dextrose with Fehling's test solution, in which 
 case the content of a glucose solution is ascertained by the quantity which is 
 
required to transform all the cuprio oxide of a fixed quantity of a copper test 
 solution into cuprio oxydule or cuprous oxide. 
 
 Neither neutral nor basic acetates of lead precipitate dextrose from its 
 solution in water, but it is totally tbrown down by ammoniacal acetate of lead 
 (i.e., basic acetate of lead to wbich ammonia is added till a precipitate is just 
 being formed). 
 
 One gramme of anhydrous dextrose dissolved in 100 com. of water and 
 mixed with 5 com. of a solution of 40 grammes of phenylhydrasin and 40 
 grammes of glacial acetic acid, completed with water to 100 c.cm., wUl yield, 
 after being heated for one hour at 100°C., a precipitate of crystallized glucosasone. 
 The weight of this glucosasone is, after cooling, filtering, washing, and drying, 
 0'32 grammes. Its fusing point is 205°, provided that care is taken to heat the 
 sample destined for the determination of the fusing point rapidly, as in the 
 contrary case this point will be too high. 
 
 Dextrose may, the same as with sucrose, be decomposed by yeast, and is also 
 subject to all fermentations mentioned under that heading. 
 
 3. Levulose. 
 
 In the sap of perfectly ripe sugar cane little or no levulose seems to occur, 
 but it may be found in unripe or over-ripe canes. In unripe cane it is principally 
 present in the parts still growing, from which it disappears as the cane ripens. 
 In dead canes, where the sucrose has already undergone partial inversion, levulose 
 occurs, of course, as one of the products of this inversion, just as in the jiiices 
 circulating in the factory, in which also levulose has arisen by inversion to some 
 extent. 
 
 Levulose appears in the form of rather hygroscopic needles, which melt at 
 93°C., and are very soluble in water and in alcohol. 
 
 It is insoluble in cold absolute alcohol, but on the other hand it is dissolved 
 in hot absolute alcohol and in ether containing alcohol. 
 
 It turns the plane of polarization to the left, and its Isevo-rotatory power 
 exceeds the dextro-rotatory power of dextrose or sucrose ; the rotation is, however, 
 much influenced by temperature, and diminishes when the latter rises. If we 
 again suppose the right-hand polarization of sucrose to be 100, the rotation 
 of a 102 levulose solution is at 0°C., 152-5 ; at 20°0., 135-6; and at 30°0., 
 127-2. 
 
 On heating levulose it is soon decomposed into water and levulosan ; therefore 
 one must be very careful when drying substances containing levulose, e.g., for the 
 determination of moisture in all products of the cane sugar industry, not to 
 break up the levulose. As moist levulose is still more liable to decomposition 
 than dry, it is advisable to dry such substances first at 60°0., and only afterwards 
 drive off the last traces of water at 100°0. The products arising from levulose 
 by the action of heat, of oxydizing agents, of acids and alkalies are the same 
 as in the case of dextrose, the only difference being that levulose decomposes 
 more quickly than dextrose. 
 
 Neither neutral nor basic acetate of lead throw down levulose from its 
 solution in pure water, but the last-mentioned reagent precipitates this sugar in 
 
9 
 
 part as soon as salts occur in the same solution, mth constituents of which basic 
 acetate of lead forms insoluble combinations. When, in this case, a precipitate of 
 a lead salt is formed, this carries down a part of the levulose as a plumbic salt. 
 For this reason clarification of levulose, containing juices or solutions with basic 
 acetate of lead, is not adequate when it is necessary to determine the glucose 
 content in the filtrate. 
 
 "When heating one gramme of anhydrous levulose dissolved in 100 c.cm. of 
 water for an hour with 5 c.cm. of the above mentioned phenylhydrasin-glacial 
 acetic acid mixture, the same glucosasone, as in the case of dextrose, is precipitated 
 but its quantity is 0'70 grammes. The fusing point of the glucosasone is of course 
 again at 205° 0. 
 
 In practical working the custom is to summarize the dextrose as well as 
 the levulose and the mixture of both known under the name of invert sugar, 
 under the common name of glucose, and to determine by analysis the amount of 
 this constituent from the quantity of copper oxide it reduces, without making 
 any distinction between the kinds, of sugar of which it is composed. Wherever in 
 the present treatise the term glucose is used, it always means that sugar or 
 mixture of sugars which has the property of reducing Fehling's test solution. 
 
 The mixture of glucoses, formed by the inversion of sucrose, consists of 
 equal parts of dextrose and of levulose, and considering that levulose turns to 
 the left in a higher degree than dextrose to the right, the mixture is sure to 
 possess a left-hand rotation, diminishing like that of levulose as soon as the 
 temperature rises. If we again suppose the figure 100 to represent the dextro- 
 rotation of sucrose, the rotation of a 20^ solution of invert sugar is at 0° C.,-36'4 ; 
 at 20° C.,-27-9 ; and at 30° 0.,-23-7 ; while it ought to be borne in mind that in 
 this case also the concentration of the solution is not without an influence on the 
 specific rotatory power. 
 
 4. Okganic Acids. 
 
 The organic acids of the sugar cane are glycolic, malic, succinic, tannic, and 
 in dead cane (as a product of decomposition) also acetic acid. Some investigators 
 report having also detected citric, tartaric, and aconitic acids, but these 
 statements have as yet not been confirmed. In ripe canes the quantity of 
 organic acid is only very trifling, and does not exceed O-lo^, of which quantity 
 0'062 is present as free acid, and the rest combined with alkali. 
 
 GlycoHo acid occurs among other constituents in unripe grapes, and is also 
 detected in beet juice bottoms, after the juice has been heavily limed and subsided. 
 Its hme salt is soluble, therefore the acid is not removed by clarification, and it 
 may be traced in the molasses in so far as it has not become decomposed during 
 manufacture. 
 
 Malic acid is found in a great many fruits and juices ; it is a very stable 
 acid and does not get broken up in the course of manufacture, its lime salt is 
 soluble in water, so that the acid is not removed by defecation of cane juice with 
 Ume. * 
 
 Succinic acid is, like malic acid, a very stable acid, and like it possesses a 
 soluble lime salt. 
 
10 
 
 Acetic acid is only to be found in dead or diseased canes as a product of 
 the decomposition of the sugar. Its lime-salt is soluble, and therefore remains in 
 the juices after liming; it has the awkward property of being very hygroscopic, and 
 this is the reason why sugar yielded by damaged or dying canes often becomes 
 moist again after being well dried. 
 
 Tannic acid of unknown composition occurs in very trifling quantities in 
 young canes and in the green tops of ripe ones. The quantity is somewhat 
 insignificant, and it combines with albumen immediately after the crushing, forming 
 an insoluble precipitate, thus it does not interfere with the further manufacture. 
 The acids mentioned here are originally from the cane and pass oyer into the 
 juice, but during manufacture such large quantities of organic acid are produced 
 by the action of lime on the glucose, that the acids from the cane have only a 
 very subordinate importance. As we have already seen, they differ according to 
 the temperature and bear the names of lactic, saccharinic, glucinic, and 
 saccharic acids, etc. ; their properties have been described above. 
 
 5. Nitrogenous Bodies. 
 
 Eipe sugar cane contains very little nitrogenous substance, only the leaves 
 and the green tops contain a rather considerable quantity, but in the ripe cane 
 itself only the buds are provided with it. A perfectly ripe cane, without the 
 leaves, contains an average of O'Oo^ nitrogen, and the whole plant, without the 
 roots, up to 0-082'. 
 
 Juice filtered through cloth was found to contain from 0'018-0'0622 of 
 nitrogen, being 0'036 in the average, and of this small amount a considerable 
 portion was not dissolved, but in the form of a colloid, for the amount of 
 nitrogen decreased greatly after filtration through filter paper. 
 
 By far the greatest part of the nitrogenous substance in sugar cane consists 
 of albumen, which occurs in unripe cane to a much greater extent than in ripe 
 cane. The nature of the albumen, or kinds of albumen, is not yet known. 
 
 Besides albumen the presence of amides or amido acids has been proved, 
 but as yet no conclusive evidence has been obtained as to whether these are 
 asparagine, aspartic acid or glycocol. At any rate their quantity is trifling, 
 amounting to about O'Oo^^ of the weight of the cane. 
 
 Finally, small amounts of xanthine bases, chiefly guanine, are isolated from 
 cane juice. 
 
 6. OOLOTIEING MATTEB. 
 
 In the peripheric strata of the rind of the sugar cane we find cells containing 
 the colouring matter, which causes the diHerent colouration of the cane. Besides 
 chlorophyll, which in every case forms the ground colour, the presence of 
 anthocyan has been detected in black and purple canes. When the canes are 
 crushed, the colouring matter passes over into the juice and imparts its colour 
 to it ; thus the juice from black cane is much darker than that from white or 
 yellow. 
 
 Next to this we find in the cane another colouring matter with which the 
 fibre is impregnated. This is colourless in a neutral state, but becomes yellow 
 
11 
 
 on contact ■with alkaline liquids. It is so firmly connected with the fibre that 
 it is impossible to remove it totally by extraction. 
 
 The colouring matter, the composition of which is still unknown, is very 
 sparingly soluble in water, better so in alcohol ; but it is insoluble in ether. 
 When exposed to the air it changes into a red colouring matter, which is 
 frequently met with in diseased or dead canes. On further oxidation, the 
 colouring matter is broken up into a dark brown substance. 
 
 7. Oanewax. 
 
 On the outside of the rind of the cane, especially near the knots, we find a 
 more or less considerable layer of wax, which is more conspicuous in some 
 varieties than in others. This wax melts at 82° 0., boils at 146° C, is insoluble 
 in water and in cold alcohol, slightly soluble in cold ether or chloroform, but 
 dissolves easily in hot alcohol, ether and chloroform, and in benzine. It is not 
 a wax properly so called, but a saturated alcohol, having 24 atoms of carbon. 
 
 8. Pectine. 
 
 We always find some pectine in cane juice, in some varieties more than in 
 others, though the composition of the soil also seems to influence its occurrence. 
 
 Pectine is only partially removed by the defecation, and more so, but even 
 then not entirely, by the carbonatation processes, and therefore it may be expected 
 in the clarified juice and in the molasses. Pectine is insoluble in acidulated 
 alcohol, and does not yield sugar on being heated with dilute acids. Its lime 
 salt is only sparingly soluble in water, but it is not quite insoluble. 
 
 On evaporating 5 grammes of pectine from cane juice with 60 com. nitric 
 acid of a specific gravity of 1"15, about 1 gramme of mucinic acid is obtained, 
 corresponding with a content of about 30^ of galactane groups in the pectine. 
 
 9. Fibre. 
 
 All fixed substances of the cane, not belonging to the juice, is sunMnarised 
 under the name of " cellulose " or fibre. The first mentioned name is not correct, 
 since the fibre only consists of 70^ of properly speaking cellulose. This cellulose 
 is incrusted with a gummy matter, called wood gum or xylan, which is firmly 
 attached to it, and increases in quantity as the cane ripens. The cellulose itself 
 is also slightly soluble in hot water or in dilute acids. This solubility diminishes, 
 however, in proportion as the canes grow older. An ammoniacal solution of 
 cupric oxide dissolves the cellulose almost entirely ; whilst hydrolysis by sulphuric 
 acid converts it into dextrose. 
 
 The wood gum or xylan occurs to the amount of 25-302 ^'^ ^^ fibre. It is 
 slightly soluble in water and in ammonia, better in limewater, and very much so 
 in caustic soda solutions. The addition of acid and alcohol causes it to be 
 precipitated as white voluminous flocks. It deflects the plane of polarization 
 strongly to the left, and is well nigh quantitatively changed into xylose by boiling 
 with dilute acids. On distillation with hydrochloric acid of 1'06 specific gravity 
 it jdelds 80^ of furfurol. Xylan is precipitated from its aqueous solution by 
 excessive quantities of Hme and barytes and by basic acetate of lead. 
 
12 
 
 Owing to tlie fact that hot water, and thus equally hot juice, extracts part» 
 of the gummy matter from the iibre, the determination of the fibre-content in 
 sugar cane and in bagasse by extraction with boiling water is apt to yield 
 erroneous (inferior) figures for that constituent. 
 
 Equally, every defecated cane juice is sure to contain more or less of this 
 gum, especially when the juice contains many fine particles of bagasse, or the 
 steamed scums have been treated with carbonate of soda. The large dose of lime 
 used in the carbonatation process on the contrary throws down the major part of 
 the dissolved cane gum. 
 
 Through the presence of the gum, which is saturated with water, the fibre 
 may contain as much as 20% of colloid water of hydration, not belonging to the 
 proper cane juice. 
 
 As a rule it still contains O'T^ of albuminoid matter and 3^ of incombustible 
 or ash, besides the already mentioned colouring matter, assuming a yellow colour 
 when put into an alkaline medium. 
 
 The total quantity of fibre is tolerably regular, between 10^ and 122 o* ^^^ 
 weight of the cane for the black Java cane. Other varieties may contaia 
 considerably more or less. 
 
 10. Incombustible Matter or Ash. 
 
 Sugar cane is a plant that absorbs very little mineral substance from the soil, 
 which is very clearly to be deduced from the trifling quantity of ash contained. 
 The constituents vary in quantity within rather narrow limits, according to the 
 quality of the soil, the manuring, and the variety of the cane, but all of them 
 are found in every cane ash. The few figures underneath may be regarded as 
 fair examples : — 
 
 
 On 
 100 cane. 
 
 On 100 parts of incombustiblp. 
 
 Constituents. 
 
 
 
 
 
 
 
 1 
 
 
 2. 
 
 3. 
 
 4. 
 
 Potash 
 
 0-153 
 O'OIO 
 
 23-0 
 1-5 
 
 12-o6 
 5-67 
 
 25-63 
 2-26 
 
 7-66 
 
 Soda 
 
 6-45 
 
 Lime 
 
 0-OlS 
 0-014 
 
 2-7 
 2-1 
 
 5-50 
 
 5-08 
 
 3-24 
 3-22 
 
 12-53 
 
 Magnesia 
 
 6-61 
 
 Oxide of iron 
 
 0-003 
 
 0-5 
 
 — 
 
 — 
 
 0-56 
 
 Silica 
 
 0-3ol 
 
 52-8 
 
 56-76 
 
 53-42 
 
 43-75 
 
 Sulphuric acid 
 
 0-016 
 
 2-4 
 
 2-60 
 
 0-53 
 
 16-53 
 
 Chlorine 
 
 0-002 
 
 0-3 
 
 , 0-20 
 
 0-92 
 
 0-21 
 
 Phosphoric acid 
 
 0-098 
 
 14-7 
 
 10-63 
 
 10-78 
 
 5-45 
 
 
 0-665 
 
 100 
 
 100 
 
 100 
 
 100 
 
 1. Loekeren, Oampagne, a.v.d. Veen Archief, 1895, 
 2 and 3. Boname, Sugar Cane, 1894, 622. 
 4. Popp KrUger, Part II., 161. 
 
CHAPTER II. 
 
 Distrihution of the Constituents in the Gane. 
 
 It is evident that the above-mentioned constituents are not to be found in the 
 same propoi'tion in every part of the cane, as this is not to he regarded as one 
 homogeneous mass but as a living organism, every part of which has to fulfil its 
 special functions, and ha,s therefore a constitution diflering from that of the 
 other parts. 
 
 The outermost part forms the rind, which is generally covered with a laj'er of 
 wax of varying dimensions and also contains the colouring matter which imparts 
 the colour to the cane. Anatomically speaking, the interior portion of the cane 
 consists of parenchyma and fibrovasoular bundles, which latter run through the 
 cane in a longitudinal direction and end in the leaves or the buds; they are 
 wrapped up and covered by the parenchyma. This consists of cells, which are 
 composed of a cell-wall, protoplasm, and the vacuole, containing the saccharine 
 juice, whilst the bundles have much thicker cell-walls and possess a very poor or 
 idmost sugarless sap. As in some parts of the cane the bundles are present in a 
 greater proportion than in other parts, the content of fibre, sugar, and water is of 
 course also variable for the different parts of the cane. Thus the periphery 
 contains more fibre than the centre and less sugar or water, while the woody lower 
 end is poorer in saccharine matter than the succulent higher joints, &c. 
 
 But the juice of all the cells is moreover far from being of a uniform 
 composition, the younger portions containing more glucose and less sucrose than 
 the older ones, causing the top end to be poorer than the middle or even the lower 
 end. In the younger portions the glucose predominates, but changes into 
 saccharose with the advance of maturity, though this phenomenon is counter- 
 balanced by the fact that when the cane is over-ripe or dying, the sucrose in the 
 oldest joints is again partially converted into glucose by inversion. 
 
 Apart from the juice in the vacuoles, which contains no more than sucrose, 
 glucose, a little salts and the organic acids, the protoplasm consists for the main 
 part of water, and this latter also contains albumen and salts; moreover, the 
 water of the fibrovasoular bundles also holds some salts in solution. Properly 
 speaking, the cane contains no less than three kinds of juice: those of the 
 vacuoles, of the protoplasm, and of the fibrovasoular bundles, of which the first 
 and the last contain their constituents in a dissolved state, while that of the 
 protoplasm moreover carries matter with it in a state of suspension. The softer 
 elements of the cane possess the purest and richest juice, so that this is at once 
 extracted by a gentle pressure ; on crushing heavily the protoplasm is rubbed to 
 a broth, mixes up with the juice first mentioned and with that of the bundles, 
 and yields a turbid, impure mixture. 
 
14 
 
 This explains the fact that cane crushed in a weak mill yields a richer and 
 purer juice than that crushed by a heavy and powerful mill. 
 
 The relation of the various constituents of the cane diflers considerably, but 
 for sound ripe cane it varies between the following limits : — 
 
 Per cent. Per cent. 
 
 Sucrose .... 12 to 18 
 
 Glucose 0'4 „ 1-5 
 
 Fibre 10 ,, 12 
 
 Ash .... 0-5 „ 0-9 
 
 Undetermined 0-5 „ I'O 
 
 "Water 70 „ 77 
 
PART II. 
 
 SUGAR MANUFACTURE. 
 
 CHAPTER I. 
 
 Extraction of the Juice. 
 
 The oldest way of extracting the juice' from sugar cane, which at the same 
 time is up to now the most usual one, is the milling process. Pormerly this was 
 performed on a small scale by crushing cane hetweeA two wooden or stone 
 cylinders, but at present cane is crushed, in practical working, between iron or 
 steel rollers, driven by steam or water. Formerly the cane was crushed only 
 once, and the extracted juice boiled into sugar, but as the bagasse still contained 
 rather a considerable quantity of saccharine juice, which was lost, the custom now 
 is to crush the bagasse from the first mill again between a second and a third set 
 of rollers, so that triple crushing is at present met with everywhere. 
 
 The most common form of sugar mill is the three-roller mill, of which two 
 rollers on the same level turn in the samie dii-ection and bear the names of " feed 
 roller " and "bagasse roller," while the third, the "head roller," is placed above 
 the other two and turns in an opposite direction. Generally the rollers of the 
 first mill are placed in such a way that the space between the feed and the head 
 rollers is such that the cane enters easily and is but slightly squeezed, but the 
 space between the head and the bagasse rollers is so small that only the crushed 
 cane fibre can pass, causing the proper crushing to take place there. The extracted 
 j^lice flows along the cylinders into a gutter placed below the mill, and the 
 bagasse is thrown out by the rotation of the cylinders. In order to ensure good 
 feeding and to carry the canes straight between the rollers, a metal plate, the 
 trash or bagasse turner, is constructed, which in some systems is movable, in 
 others fixed. The proper adjustment of the bagasse turner is one of the principal 
 points in the milling work, and like the adjustment of the rollers requires the 
 continual attention of the engineer. 
 
 In this treatise, which is especially destined for the chemist, it would not be 
 in place to enter into detail on the subject, hence the following remarks may be 
 sufficient. The proper position of the rollers, i.e., the space between the feed 
 roUer and the head roUer, and between the latter and the bagasse roller, depends 
 entirely on the amount of cane that should be worked up in twenty-four hours 
 
16 
 
 ■with a given velocity of the mill, and on the quantity of juice that is allowed to 
 remain in the bagasse, according to the capacity of the factory. These conditions 
 being stated, the adjustment of the bagasse turner depends on them, and this 
 ought to be changed as the mutual distance of the rollers changes.' This point 
 dominates the mill- work and regulates the work so as to cause the maximum of 
 cane to be crushed in a given time, whilst the accurate adjustment of the trash 
 turner prevents the jamming of cane fibre between the rollers and diminishes con- 
 siderably the breaking of axles, standards, and wheels. The distance between the 
 bagasse turner and the bagasse roller is regulated according to the purpose the 
 mUl is used for; it is larger in the first mill, where only canes are crushed, than 
 in the second or third, where the already finely divided bagasse has to be 
 exhausted. As a rule, the rollers of the first mill make from 2 to 2J turns per 
 minute, those of the second mill 1^ to 2, and those of the third not more than 
 14 or If. 
 
 Besides the three-i'oller mills, two-roller ones are also used, the rollers of 
 which are placed .one above another, and the cane is introduced between 
 them by means of a, cane carrier ; moreover, we find mills having four or eight 
 rollers, but, as already remarked, the three-roller mill is the most common 
 form. 
 
 In order to relieve the miUs, and with a view to crush more cane in the same 
 time with a given power, two new contrivances have lately been introduced, 
 intended to divide the cane into small pieces before its entering the mill. They 
 are the Eoss cane-cutter and the cane-shredder. The former cuts the cane in 
 pieces of about four inches and afterwards divides it into thin slices, while the 
 latter reduces the cane to fibre between two rows of teeth and carries it to the 
 mill. If the knives of the cutter and the teeth of the shredder are sufficiently 
 sharp, this can be effected without any loss of juice; the divided cane is afterwards 
 crushed in the same way as the canes themselves, by mills, the rollers of which 
 must be further apart than in the case of entire canes, because they receive them 
 in a more voluminous form. 
 
 A third engine, the "crusher," consists chiefly of a set of roUers provided 
 with V formed teeth, which are placed so close together that the canes passing 
 through them are slightly squeezed, and therefore the first mill can crush them 
 more easily than the ordinary cane. Contrary to what has been observed when 
 speaking of the former two contrivances, this one extracts a part of the 
 juice. 
 
 When using double or triple crushing, it is advisable to use the most powerful 
 mill as the first mill, so that it may express 60 to 65^ of juice on the weight of the 
 cane, leaving only 25 to 30^ of juice in the bagasse. This is transferred by bagassse 
 carriers to the second mill, in which the distance of the rollers is smaller than in 
 the first one, causing the bagasse to undergo a heavier pressure and to part with 
 a further portion of its juice. After this the bagasse is again cnished in a third 
 mill of the same dimensions as the second, which would therefore not do any 
 work if maceration were not applied between the second and third mUl. However 
 
 •The construction and adjusting of tlie bagasse turner are described furtlier on in Part IV. 
 
17 
 
 lieavily cane may be crushed it is still impossible to express the last remnant of 
 juice, and the residuum will of course contain sugar, being the original cane 
 juice. When water is poured on the bagasse this juice gets diluted, and after 
 crushing the bagasse to its fratner content of juice, it will then contain 
 the same amount of diluted, but therefore less saccharine juice, causing 
 less loss of sugar, so that maceration considerably improves the juice 
 extraction. 
 
 Cane that has been crushed once, or inmost factories even twice, and thus has 
 lost a great deal of its juice, is macerated at the moment that the bagasse oozes out 
 from between the rollers, and, relieved from the heavy pressure, expands by its 
 own elasticity and eagerly absorbs water. By the crushing in the mill the ceU- 
 walls have already been torn, allowing the maceration water to at once dilute the 
 stiU remaining juice ; further water is poured on the partially exhausted bagasse 
 on its way from one mill to another, and it is moreover turned again in some 
 factories, causing the juice which is expressed by the next mill to be highly 
 diluted. A calculation wUl make this point clear. Suppose that in a factory 
 having triple crushing a maceration of 15|| on the weight of cane is applied 
 after the second mill on bagasse of cane that has already lost 72^ of juice and 
 therefore still contains 18^ of juice on the weight of cane, and that the third mill 
 squeezes this macerated bagasse again to the same content of juice as when it left 
 the second mill, the following is the result, assuming that juice and maceration 
 water have been completely mixed in the bagasse : The bagasse contained 18^ of 
 juice ; water^was added to an amount of IS^, therefore the macerated bagasse 
 contained 18X15 := 33^ of diluted juice, of which ^4 is original, undiluted juice. 
 Now the third mill expresses the bagasse again to 18^ of juice on the weight of 
 cane, causing 15^ of diluted juice, corresponding to 44x15 ^8*22 of original 
 juice to be extracted, which without maceration and recrushing would have 
 been lost. 
 
 It is true that in the short time that the bagasse requires to pass from one 
 miU to another the maceration water cannot mix up completely with the juice 
 still remaining in the bagasse ; a mixture of 80^ is very satisfactory, and owing 
 to this the diluted juice extracted by the last mill does not contain so much sugar 
 as is calculated here. 
 
 Supposing a mixture of 80^, then 80^ of the juice in bagasse or 
 
 18 V 80 
 
 — -^ — = 14 "4 parts of original juice mix up with 15 parts of water. These 
 
 14*4 
 29-4 parts of diluted juice contain each—— parts of original cane juice; there- 
 by *^ 
 
 14'4 
 fore the 15 parts of juice- extracted contam _- X 15 = 7"35 parts of original 
 
 juice, instead of the 8'2^ which would be the case if the maceration water had 
 become totally mixed with the juice in the bagasse. 
 
 In many sugar factories the bagasse is macerated between the first and 
 second mills with the diluted juice from the last mill, and with pure water 
 between the second and the last mill. All the juice coming from the last mill is 
 
 2 
 
18 
 
 poured over the bagasse from the first mill, and the juice from the first and 
 second mill is conveyed into the clarifiers. This maceration with last mill's 
 juice can only be applied if the cane is crushed so heavily in the first mill 
 that the first bagasse can easily absorb liquid. A feeble first mill only 
 squeezes the canes, and they leave it with a smooth surface and are unable 
 to absorb the last mill juice. In this case this saccharine liquid is again 
 extracted by the second mill without having diluted the juice in the bagasse, 
 or it soaks through the planks of the carrier on to the floor and is con- 
 sequently lost. 
 
 By the work of the cane-preparing apparatus, such as cutters, shredders or 
 crushers, it is feasible to obtain the first mill's bagasse in such a spongeous 
 condition that it eagerly absorbs the last mill juice, and therefore contains, after 
 leaving the second mill, a more dilute juice than when the maceration with last 
 mill juice has been omitted, or when that juice has only moistened its surface 
 and has not penetrated into the interior of the layer of bagasse on the carrier. 
 It is evident that the cane-preparing machines not only allow quicker 
 working and decrease the risk of break-downs, but for the above-mentioned 
 reason also bring along a better juice extraction while maintaining the same 
 dilution. 
 
 It is advisable to pour the last mill juice on the bagasse by means 
 of an open gutter and not through a perforated tube, as is the custom 
 with maceration water. Notwithstanding the fact that this juice passes 
 through copper strainers it may carry along fine particles of bagasse, which 
 might choke up the openings of the supply tube. The best thing is to allow 
 the juice to flow over the brim of an inclined open gutter placed over the 
 bagasse carrier. 
 
 As to the amount of juice extracted, it matters little whether hot or cold 
 maceration water is used. Hot water has the disadvantage of dissolving more 
 gummy matter from the bagasse and bringing it over into the juice, but still it is 
 to be preferred from a practical point of view. The cold water used for the 
 purpose in sugar mills is ordinarily dirty and needs filtration, therefore likewise 
 with a view of preventing the choking up of the apertures in the supply pipes 
 or in the " Streudiisen " it is better to use the condensed water from the hot 
 well. As it is an advantage to spread the water with force on the bagasse, the 
 maceration supply is generally connected with the feed pump of the boilers. In 
 this simple way one obtains without special machinery a steady supply of hot 
 water under considerable pressure. 
 
 This process of continuous maceration and extraction, however, has its limits, 
 as it is not economical to go on in this way in order to extract all the sugar from 
 the cane, as in this case the cost of evaporating the huge quantities of miaceration 
 water would exceed the yield of the extra sugar thus obtained. Moreover, by 
 the action of the repeated maceration and crushing, all kinds of bodies are 
 extracted from the fibre and go over into the juice, causing it to become more 
 impure and more troublesome to clarify. It is advisable for every factory to 
 regulate the mill work according to the water and sucrose content of the last 
 
19 
 
 bagasse, and to regulate the maceration by tbe specific gravity of the last mill 
 juice. The more powerful the mills are the m.ore -work may be claimed of them, 
 and the drier and more exhausted the bagasse may be expected to be, without 
 being subject to fixed rules, so that no exact figures can be given here on this 
 point. Factories possessed of a large evaporating plant and of sufficient steam, 
 may go farther with maceration than those where stoppage in the course of 
 working, owing to want of capacity, is to be feared. Besides this, copious 
 maceration will be more in place when crushing cane with juice of a high 
 saccharine content, than in cases where poor cane has to be worked up. In any 
 case the extent of the maceration is, however, to be regulated by taking care to 
 maintain the diluted juice from the last mill at the same specific gravity. When 
 crushing canes having a rich juice, m.ore maceration water will be required to 
 dilute the last portions of it to the fixed specific gravity than when a cane with a 
 poor juice is crushed, and thus the maceration is regulated by the constant testing 
 of the last mill juice by the Brix hydrometer, and so always obtaining bagasse 
 containing juice with an invariable quantum of dry substance. Owing to the 
 circumstance that the Brix hydrometer only ascertains the quantity of dry 
 substance and not that of sucrose, the sucrose amount of the bagasse cannot be 
 regulated in the same exact way, but the proportion between dry substance and 
 sucrose does not differ so much in _the same factory that any great mistake can 
 ensue. If care is taken that the mills always crush with a uniform power, and 
 the resulting bagasse therefrom contains a constantly identical amount of water 
 (juice), then, owing to the uniformity of the last mill juice, the sucrose content of 
 the bagasse is also always the same within certain limits, which gives great 
 regularity to the work. The quantity of juice extracted from 100 parts of cane 
 now depends only on the amount of fibre in the cane, and this quantity 
 diminishes for two reasons when the amoxmt of fibre rises. Pirstly, cane 
 with much fibre contains a proportionately smaller quantity of juice ; and, 
 secondly, the quantity of bagasse is increased, and hence also the quantity 
 of juice which it contains and that of the sucrose in it which is to be 
 eliminated. 
 
 We do not, even with the best and most powerful mills, succeed in expressing 
 more than 90 to 94^ of the sucrose of the cane, the result being that the balance 
 of 10 to 6^ is consumed in the fuel,* while at the same time the heavy pressure 
 causes a great quantity of impurities to pass over in the juice. This, as well as 
 the example of the beet sugar industry, induced the planters to try to substitute 
 the diffusion process for the mill, but this has as yet not met with general 
 approval. 
 
 The principle of diffusion is based on the property which many bodies possess, 
 when in solution, of passing through a membrane, if on the other side of it a 
 liquid is present containing a smaller quantity of the like body in solution, this 
 process going on until a state of equilibrium is attained between the liquids 
 
 * In former years whea the methods and mills were not so perfect as they are now, the amount of 
 sucrose remaining in the bagasse was larger; losses of 12% of sucrose in cane were formerly no 
 exceptions. 
 
20 
 
 on eaoh side of the membrane. The bodies having this property, are principally 
 those capable of becoming crystallized, so-called crystalloids, while gummy and 
 albuminoid matters, so-called ooUoids, diffuse very slowly or not at aU. In the 
 living cell the protoplasmic tegument of the cell wall cannot be regarded as a 
 dialytic membrane, but as soon as the ceU is kiUed by heat, or in some other way, 
 the protoplasm becomes pervious. 
 
 In practical working, diffusion is conducted by slicing canes in chips by 
 means of slicing machines, and transferring the chips into large vessels called 
 diflusers, whore hot water is poured on them, causing the cells to die, and sucrose, 
 glucose, acids and some incombustible matter to pass through the cell walls until 
 the consistency of the juice inside and outside of the cells has become the same. 
 Afterwards the water, or more properly speaking, the diffusion juice, is drawn off 
 and poured upon a fresh quantity of slices, when it becomes still further enriched, 
 and this process is repeated untU. the amount of sucrose in the diffusion juice has 
 reached as nearly as possible that of the original cane juice. The slices that have 
 been partially exhausted by the most concentrated juice have more dilute diffusion 
 juice poured over them, and finally water, and are totally exhausted, which 
 operation, now that the cells are dead, may be efiected without applying heat 
 every time. Eventually, the slices, which during all this time have remained in 
 the same diffuser, have successively been in contact with a diEfusion juice of high 
 concentration, heated with steam to kUl the cells, afterwards with more dilute 
 juice and finally with water, so that when they are removed from the diffusion 
 battery by opening the bottom of the diffuser they have a minimum, content of 
 sucrose. 
 
 The technical part, i.e., construction and treatment of the diffusion battery 
 may remain undesoribed here, because it is the same as has already been 
 frequently described in all the handbooks on the beet sugar industry. It may 
 just be mentioned that the most advantageous way of heating is by steaming 
 the diffuser filled with fresh chips to a temperature of 90° 0., and not warming 
 the others. At this temperature the cells die, and the sucrose diffuses, whilst 
 albumen coagulates. After the diffusion juice is drawn off, its place is taken by 
 juice which has been in contact with previously heated chips and hence has a 
 lower temperature, and this goes on untU the exhausted chips leave the diffusion 
 battery with the same temperature they had when entering into it, so that in the 
 chips no heat becomes lost. Nevertheless experience has shown that with this 
 mode of working almost all the sucrose of the cane is extracted, while at the 
 comparative low temperature prevailing in the battery, no inversion takes place 
 and no organic substances are decomposed. In the process of cane diffusion, 
 glucose diffuses the fastest, then sucrose, and afterwards some incombustible 
 matters; albumen, colouring matter, pectine, etc., which cannot pass through 
 the cell wall, are to be found in small quantity in the juice, owing to the fact 
 that the cells which were damaged in the slicing have poured out their total 
 contents in the juice. 
 
 The following table shows the composition of the juice in the different 
 vessels of a diffusion battery : — * 
 
21 
 
 No. of the 
 Yessels. 
 
 Cane juice 
 
 1 
 
 2 
 
 3 
 
 4 
 
 5 
 
 6 
 
 7 
 
 8 
 
 9.. .. 
 
 10 
 
 11 
 
 12 
 
 13 
 
 14 
 
 - 
 
 GO 
 
 5 
 
 „1. 
 Ill 
 1-11 
 
 a 
 
 1 
 1 
 
 M 
 
 i 
 
 .s-c 
 
 6 
 
 S 
 
 S 
 
 s 
 
 o 
 
 5 
 
 18-33 
 
 16-14 
 
 0-81 
 
 0-283 
 
 0-290 
 
 0-81 
 
 89 
 
 5-2 
 
 12-6 
 
 10-74 
 
 0-58 
 
 0-117 
 
 0-170 
 
 1 
 
 85-2 
 
 5-4 
 
 10-21 
 
 8-59 
 
 0-40 
 
 0-103 
 
 0-162 
 
 0-96 
 
 84-1 
 
 4-7 
 
 7-1 
 
 5-95 
 
 0-25 
 
 0-085 
 
 0-135 
 
 0-68 
 
 83-8 
 
 4-2 
 
 5-5 
 
 4-71 
 
 0-17 
 
 0-062 
 
 0-120 
 
 0-43 
 
 80 
 
 3-6 
 
 4-4 
 
 3-71 
 
 0-15 
 
 0067 
 
 0-109 
 
 0-36 
 
 84-3 
 
 4 
 
 3-4 
 
 2-82 
 
 0-12 
 
 0-061 
 
 0-101 
 
 0-30 
 
 82-9 
 
 4-3 
 
 2-81 
 
 2-2() 
 
 0-08 
 
 0-058 
 
 0-085 
 
 0-33 
 
 80-6 
 
 3-6 
 
 2-4 
 
 1-89 
 
 0-08 
 
 0-043 
 
 0-079 
 
 0-31 
 
 75-4 
 
 4-3 
 
 1-9 
 
 1-42 
 
 0-04 
 
 0-030 
 
 0-081 
 
 0-33 
 
 74-7 
 
 3 
 
 1-6 
 
 1-24 
 
 — 
 
 0-020 
 
 0-070 
 
 0-27 
 
 77-5 
 
 — 
 
 1-2 
 
 0-99 
 
 — 
 
 — 
 
 0-054 
 
 0-16 
 
 82-5 
 
 — 
 
 0-8 
 
 0-39 
 
 — 
 
 — 
 
 0-043 
 
 0-37 
 
 49 
 
 — 
 
 0-5 
 
 0-28 
 
 — 
 
 — 
 
 0-031 
 
 0-19 
 
 56 
 
 — 
 
 0-39 
 
 0-31 
 
 — 
 
 — 
 
 0-013 
 
 0-08 
 
 70 
 
 — 
 
 1-9 
 1-6 
 1-9 
 2-3 
 2-5 
 2-7 
 3-6 
 3-8 
 4-2 
 5-7 
 5-7 
 5-5 
 
 11 
 
 11 
 4 
 
 The contest between diffusion and milling becomes more and more decided 
 in favour of the latter process, which is principally due to the many improve- 
 ments made in the mills and cane preparing apparatuses in the last few years. 
 The extraction by means of mills is no longer so inferior to diffusion work as it 
 used to be. ^Further, the construction of the mills is much improved too, causing 
 breakdowns to occur far less frequently than before and to be repaired much more 
 quickly than in former times. Finally, the introduction of cutters and shredders 
 has contributed considerably to ensure a -more regular working of the whole 
 milling plant. 
 
 A great advantage of mills is that their capacity permits more variations of 
 output than is the case with the diffusion battery. If necessary it is possible 
 (when, for instance, burnt cane must be crushed at once) to crush 600 tons a day 
 with a miUing plant intended to crush, say 450 tons, provided the other stations 
 of the factory can tackle and work up all the juice. It is evident that such an 
 enormous increase of work done cannot but influence its quality, so that a poorer 
 extraction will be the consequence ; and granting even this, we must not overlook 
 the fact that a diffusion battery may conceivably accomplish such excess of work. 
 But even if we allow a very poor extraction it would not be feasible to work 
 up all the canes, as the slicing machine might prove insufficient to properly slice 
 all the surplus cane. On the other hand, the advantages of diffusion are that it 
 extracts nearly all the sugar from the cane in the form of a pure juice, the 
 greater part of the impurities remaining behind in the bagasse, so that the juice 
 is easily workable. There is also less danger of stoppage from breakdown, for 
 if one diffuser gives way it is disconnected and the work carried on with the 
 others, which is not so feasible with iriin work. 
 
22 
 
 The disadvantages are that more hands are required by the diffusion system, 
 and that they must be chiefly workmen acquainted with diffusion. Moreover, the 
 difiusion juice is very much diluted (up to 20^ and sometimes beyond), and a large 
 quantity of steam is required to ef aporate the diluting water. It is true that in some 
 factories working with the mill the dilution by maceration is not less than 20^, but 
 only in case they are crushing canes with a high saccharine content which renders 
 such dilution worth the while; on the other hand, it is not possible in diffusion to 
 diminish the dilution in the case of poor cane, so that poor and rich juices are equally 
 highly diluted. Finally, the slicing machine costs a great deal in steam and mainten- 
 ance, as it has very heavy work to do in cutting up all the hard cane into thin slices, 
 and the exhausted slices contain so much water that they have to be freed from the 
 excess by means of a mill before being dried in the sun to form serviceable fuel. 
 Naturally the mill has nothing like so much to do as when it is used for cane 
 crushing, but still it is a great inconvenience to be obliged to have a mill apparatus 
 along with the diflusion battery. Then the bagasse, which is first cut 
 and then ground and dried, is much finer and more powdery than cane bagasse, 
 which has ooly been ground, and it supplies a less valuable fuel. Against the 
 advantages of extracting more sugar and having a pure diffusion juice, along 
 with regular working, we have thus to put the disadvantages of requiring more, 
 and also more skilled, workmen, being compelled to use more steam, and getting 
 a less valuable fuel as an after-product, whilst the capacity of the station does 
 not adapt itself so well to a decrease or increase in the quantity of cane to be 
 worked up as with a milling plant. 
 
 Finally, at every stoppage of the diffusion battery, we have to face the 
 problem of what to do. Work off the whole battery and gain as much as possible 
 at the cost of a huge dilution, or stop adding water when the cane is only halfway 
 exhausted. 
 
 Ordinarily one chooses a compromise between the two alternatives and thus 
 has at each stoppage a considerable loss of saccharine matter as well as a great 
 dilution which costs much valuable fuel. As the cane is not in store as beetroots 
 are in Europe, and the supply may be very irregular in rainy weather, this 
 drawback connected with stopping a diffusion battery is of a much more serious 
 character than in Europe, while stopping does not affect the milling work. 
 
CHAPTER II. 
 
 Composition of the Juice. 
 
 As has already been observed, the composition of cane juice as expressed by 
 the mill is quite different from that obtained by diffusion, the latter containing 
 cousiderably less impurities. Cane juice, as it comes from the mills, is an opaque 
 liquid, covered with froth, owing to the imprisoned little air bubbles it contains, 
 and having a coloration varying according to the colour of the cane from which 
 it has been expressed, from grey to dark green. It contains in solution all the 
 soluble constituents of the cane, such as sucrose, glucose, salts, organic acids and 
 pectine, and in suspension, besides the air already mentioned, fine bagasse fibres, 
 sand and clay (adhering to the cane), and colouring matter and albumen, which 
 latter body also occurs in solution in case unripe canes or green cane-tops have been 
 crushed together with the ripe canes. Fresh mill juice has an acid reaction and 
 owing to the presence of pectine and albumen is a viscous liquid that cannot be 
 filtered when cold, hence the suspended constituents cannot be removed without 
 steaming, and we have therefore to be content with keeping back the larger 
 particles of bagasse by copper sieves before the juice is worked up. The proportion 
 in which the chief constituents occur in the juice is very different, and depends, 
 am^ong other things, on the variety and age of the cane, the nature of the soil, 
 the manuring, the climate, and even on the power of the mills. In the main, 
 the figures for sucrose and glucose show the greatest differences, while on the 
 contrary the other elements, at least in sound and ripe cane, do not vary much ; 
 in dead or unripe cane these figures also show great differences, and especially in 
 the former case the amount of acid will increase considerably. Apart from the 
 difference between the juice of various kinds of cane, the same quality of cane may 
 yield juice of a different composition according to the degree of pressure 
 it has undergone during the crushing. With heavy pressure the increase is 
 principally in the amount of constituents of the cell-wall and the protoplasm, 
 whilst the saccharine matter either remains unchanged or diminishes, causing 
 the juice jdelded by the second or third mill to be more impure than that of 
 the first, though as a rule their glucose content is inferior. This phenomenon is 
 easily explained when we remember the anatomical structui-e of the cane. The 
 saccharine juice, which, as has previously been shown, does not contain, besides 
 water and sucrose, anything but a little glucose, ash, and incombustible matter, 
 is enclosed in cells, the woody walls of which are covered inside with a semi-liquid 
 protoplasm. A gentle pressure causes the cells to split and bursts the walls, 
 allowing the pure juice to flow out ; with a heavy pressure, however, the juice is 
 commingled with the protoplasm, at the same time the soft elements of the fibre 
 are loosened, and so a kind of diluted broth flows from the mOls instead of a clear 
 juice. Maceration dilutes this broth stUl fiu-ther, and facilitates its expression, 
 which explains why the later juices contain more carbo-hydrates insoluble in 
 
24 
 
 alcohol (summarized under the name of pectine) than the first mill juice. 
 Moreover the hard, -woody rind is only broken by the heaviest pressure, hence the 
 second and third mill juices are much darker coloured than the first. The only 
 thing that seems improbable at the first view is that the first mill juice is richer 
 in glucose than the later ones, but this fact is only to be ascribed to the top of 
 the cane being at the same time the softest part and also containing the most 
 glucose. Gentle pressure therefore expresses this part easily and this imparts to 
 the first juice proportionally more glucose than to the other juices in which 
 principally the juice of the older parts is represented. 
 
 A good example showing the difference of cane juice extracted by a series of 
 three mills from a similar sample of cane without maceration is given here. 
 
 Constituents. 
 
 1st mill. 
 
 2nd mill. 
 
 Srd mill. 
 
 Brix 
 
 Sucrose 
 
 19-2 
 
 16-49 
 1-98 
 0-28 
 0-125 
 0-025 
 0-048 
 
 85-9 
 
 12-1 
 
 light 
 
 19-3 
 
 16-33 
 1-57 
 0-41 
 0-376 
 0-092 
 0-072 
 
 84-4 
 9-6 
 
 dark 
 
 19-0 
 15-95 
 1-52 
 
 Ash 
 
 0-42 
 
 Grum and Pectine 
 
 Albumen 
 
 Free Acid 
 
 Quotient of purity 
 
 1-250 
 0-054 
 0-096 
 84-0 
 9-5 
 
 Coloration 
 
 very dark 
 
 As a matter of fact, diffusion juice does not show similar differences, firstly 
 because only one juice is obtained, and secondly because but few cells are opened. 
 The diffused juice, properly so called, is free from albumen and pectine, but as 
 the slicing machine cuts through a certain number of cells, their contents are 
 poured out irito the juice, so that in practical working diffusion juice is sure to 
 contain a small quantity of pectine, colouring matter and albumen. On the other 
 hand, the hot water of the diffusion battery dissolves a little of the gummy matter 
 of the cane fibre, causing the diffusion juice to contain more gum than a miU 
 juice. Neither enclosed air bubbles nor bagasse fibres are met with in the 
 diffusion juice, at the same time the amount of sand and clay carried along with 
 the juice is also trifling. Another advantage of this juice is that it can be much 
 more accurately measured, because the surface of the liquid is flat and not 
 covered with froth as mill juice usually is. 
 
CHAPTER III. 
 
 Claeifioation. 
 
 The first operation that cane juice undergoes is that of clarification, which 
 removes the impurities as far as possible, destroys- all substances producing 
 sourness and causing deterioration, and thus prevents the loss of sugar. This 
 ought to be performed as quickly as possible, in order to aUow the clarified juice 
 to be concentrated without much delay, as it is only in concentrated solution that 
 sugar is capable of resisting the action of ferments or micro-organisms. 
 
 Excepting heat, which coagulates the albumen, the agent which from the 
 earliest times has been used for clarification, and which still maintains its ground, 
 although a great many other clarifying agents have been recommended as 
 substitutes, is lime, which has the advantages of being very suitable for the 
 purpose, of being cheap, and obtainable every-where. The methods of clarification 
 may be divided into two distinct classes, viz., defecation and carbonatation, which 
 may be applied in various ways. In defecation only a small quantity of lime is 
 used, so that very little or no excess of lime remains after clarification, while in 
 the carbonatation process the juice is heavily limed and the excess afterwards 
 removed by carbonic acid. 
 
 I. Defecation. 
 1. Heating. Liming. Settling. 
 
 The quantity of lime used in the defecation process is just sufficient to 
 neutralize the free acids of the juice, preventing them from afterwards causing 
 inversion ; further, the lime combines with the albumen, which had previously 
 been suspended in the juice in a gelatinous form, but is now coagulated both by 
 the action of lime and of heat. The acid calcium phosphates are precipitated as 
 flocculent tribasic phosphate, as well as a part of the pectine. All these flocculent 
 precipitates envelop the suspended particles of bagasse, the wax, clay, &c., and 
 after being heated to its boiling point the juice is divided into a clear limpid liquid 
 and thick frothy layer of scums. 
 
 The nature of such scums is shown by the figures here given of the analj'sis 
 of a sample, which still contains a part of the juice : — 
 
 Water 69-72 
 
 Sucrose 10-20 
 
 Glucose 0-71 
 
 Wax 4-12 
 
 Albumen 1-80 
 
 Ash 8-10 
 
 Undetermined 5-35 
 
 100-00 
 
 The ash consists of : — 
 
 Phosphate of Lime . . . . 2-92 
 
 Silica 0-37 
 
 Iron and Alumina 1-40 
 
 Magnesia 0-22 
 
 Sand and Clay 2-82 
 
 Undetermined 0-37 
 
 8-10 
 
26 
 
 A knowledge of the action of lime on cane juices of different constitution 
 may be derived from the analyses in the subjoined table, showing that lime 
 precipitates especially albumen, gums, and pectine, and slightly attacks glucose. 
 
 Constituents. 
 
 1st mill. 
 
 2nd 
 
 mill. 
 
 3rd mill. 
 
 Before After 
 Defecation. 
 
 Before After 
 Defecation. 
 
 Before After 
 Defecation. 
 
 Brix 
 
 19-2 
 
 19-2 
 
 19-3 
 
 19-7 
 
 19-0 
 
 19-4 
 
 Sucrose 
 
 16-49 
 
 17-06 
 
 16-33 
 
 17-06 
 
 15-95 
 
 16-40 
 
 Glucose 
 
 1-98 
 
 2 
 
 1-57 
 
 1-58 
 
 1-52 
 
 1-52 
 
 Gums and Pectine 
 
 0-125 
 
 0-071 
 
 0-376 
 
 0-120 
 
 1-250 
 
 0-840 
 
 Albumen 
 
 0-023 
 
 — 
 
 0-092 
 
 — 
 
 0-054 
 
 — 
 
 Quotient of purity 
 
 85-9 
 
 87-5 
 
 84-4 
 
 86-6 
 
 84 
 
 84-5 
 
 Glucose ratio 
 
 12-1 
 
 11-7 
 
 9-6 
 
 9-2 
 
 9-5 
 
 9-3 
 
 The estimation of the quantity of lime necessary for clarification is the most 
 important point in the defecation process. When the quantity has been too 
 small, the phosphoric acid and the albumen are imperfectly precipitated, and the 
 insufficiently tempered juice settles slowly and can only with difficulty be 
 clarified. When too much lime is being used the impurities are easily thrown 
 down, and the juice settles quickly. But then another difficulty arises. Lime, 
 like every other alkaline agent, acts, at the high temperature at which the 
 defecation is conducted, on the glucose, forming with it lime salts of organic 
 acids, which are dark coloured and easily decomposed and transformed into acid 
 substances which cause inversion of the sugar. Moreover, these lime salts retard 
 the evaporation and crystallization, and by their viscosity cause considerable loss 
 and annoyance on curing. The greatest care in tempering is therefore advisable, 
 and if there remains a doubt as to whether the exact quantity is being used, it is 
 better to add a little too much rather than too little, for in an insufficiently 
 tempered juice the impurities still remaining cause much trouble during the whole 
 course of manufacture, while an overtempered one may always be neutralized by 
 phosphoric or sulphurous acid. 
 
 The amount of lime necessary for tempering is ascertained in different ways. 
 Some people use just so much lime as is necessary for clarified juice to produce a 
 faint alkaline reaction on litmus or tumeric paper; others ascertain in the 
 laboratory how many c.cm. of lime-milk are sufficient to clarify properly one 
 litre of juice at its boiling point, and use the same proportion in the factory. 
 The best method is as follows : Pirst of all, in ordinary working, as much lime is 
 added to the juice as seems appropriate, say two gallons of milk of lime of 15° B. 
 to 500 gallons of juice, and clarification is effected as usual. Then a little juice 
 is taken from the clarifiers, filtered through paper into a test tube with a few 
 drops of sucrate of lime solution added.* If a precipitate is formed it is evident 
 
 ** This solution is made by shaking up lime with a 20% sucrose solution, and filtering. It is 
 much to be preferred to lime water, because a alight precipitation can be better observed with this 
 test solution than with lime water. 
 
27 
 
 that tte juice still contains impurities, and that therefore too little lune has 
 been used. In the next clarifier a somewhat larger quantity of mili of 
 lime is used in tempering, the juice is again tested, and if it again becomes 
 turbid with the sucrate of lime test solution, the quantity of lime is 
 again increased until the filtered juice remains clear after the addition of the 
 test solution. If, on the contrary, the sucrate .of lime leaves the juice clear at 
 the first test, either just sufficient or too much lime has been added to the juice. 
 In order to settle this point we gradually diminish the quantity of Hme in 
 tempering until the juice becomes under-tempered, when the amount of lime is 
 slightly increased, and this quantity is adopted as the correct one. 
 
 This method seems rather complicated, but after some experience and practice 
 the proper quantity is soon found after a few tests. As the chief aim of clarification 
 is to get speedily a juice that settles easily, this way of determining the necessary 
 quantity of lime is the most rational one, and if so much Hme is required as to 
 make the juice alkaline after clarification, it may afterwards be neutralized by 
 phosphoric or sulphurous acid. When making high-class sugar a slightly acid 
 reaction of the juice is even an advantage, but in making the so-called 
 " non-chemical" sugar, the juice should be neutral or even a little alkaline, for 
 in these sugars a rather considerable amount of molasses remains between the 
 sugar crystals, which in the case of acidity of the juice gives rise to inversion and 
 deterioration of the sugar. 
 
 A great difficulty in the proper conduct of the clarification is the varying 
 composition of the mill juice if canes from different fields are being crushed at 
 the same time. The juice of the canes of each field requires its own special 
 quantity of lime, and if canes of different fields are crushed together, the 
 composition of the mill juice varies every moment, and hence also the quantity 
 of lime necessary for clarification. Of course it is impossible to determine it for 
 each clarification, and hence defecation is a difficult and somewhat uncertain 
 operation. 
 
 The mill juice is filtered through copper strainers, and measured in 
 measuring tanks where it is Umed, it next passes through a juice-heater, and then 
 enters the clarifiers. In these the defecation takes place, and it may be conducted 
 in two different ways, depending on the manner in which the juice is allowed to 
 settle. In the first method the juice settles in the same vessel in which it has 
 been heated, while in the other the limed and heated juice is run into settling 
 tanks. When adopting the first method the juice is heated to 95° 0. in 
 hemispherical copper pans provided with a steam-jacket, into which steam is 
 admitted, which heats the juice as quickly as possible. During this time the 
 now precipitated impurities coagulate, envelop the suspended particles, and form^ 
 with the air bubbles escaping from the hot juice, a frothy, dark-coloured layer of 
 scums, underneath which is the clear juice. Only the heavy impm-ities, such as 
 sand, clay, &c. , sink to the bottom and form also a layer of impurities, so that 
 the cane juice is separated into three layers, of which the middle one, consisting 
 of clarified juice, is the greatest. The juice is heated until the layer of scum is 
 just beginning to burst (cracking point) ; the supply of steam is then immediately 
 shut off, as, if not, the juice would suddenly boil over, and become partly lost. The 
 
28 
 
 juice is now allo-wed to settle, and afterwards let ofl through a hole at the bottom 
 of the pan, which is fitted with a pipe closed by a three-way cock. By simply 
 turning the plug one is able to draw off successively the heavy impurities, the 
 clean juice, and finally the scum, each of these being conducted into its own 
 gutter. The first and third portions, i.e., the heavy impurities and the scums, are 
 run into the scum tank, whUe the clean juice is conducted to the evaporators or 
 to the eliminating pans. The three-way cook and the gutters should be placed 
 in an easily accessible and well-lighted position, so as to admit of complete control 
 which is indispensable in this operation, 
 
 In the other method, the limed juice, after having passed through a juice- 
 heater, is boiled in iron pans, through which the steam is led by means of coils. 
 As soon as the juice boils a cock is opened at the bottom of the pan, and the hot 
 juice flows into the settling tanks, where the separation of the clear juice from 
 the scum takes place. As the air in this case has been completely driven out by 
 the violent ebullition, the scum does not remain in a frothy mass on the surface, 
 but settles gradually, leaving the juice quite clear. 
 
 Instead of these pans, most factories are provided with Fletcher pans ; these 
 are cylindrical iron pans carrying a broad gutter. In the pans we find a steam 
 chamber, suspended in such a way that it almost, but not quite, reaches the 
 bottom. The steam chamber is perforated by a number of tubes in which the 
 juice circulates, and thus easily absorbs the heat of the steam introduced in the 
 steam chamber, causing it to boil rapidly. 
 
 At first the frothy scum comes to the surface and can be driven into the 
 gutter by long skimmers, whence it flows into the scum tank. When no dark 
 coloured particles are visible at the surface, but only a white mass of steam bubbles, 
 the steam supply is stopped and the juice with the heavy impurities is let ofl into 
 the settling tanks. 
 
 In many places the juice is heated to about 90° in the juice-heater, and 
 then allowed to flow through one or more Fletcher pans, in which it boils 
 rapidly, and next runs into the settling tanks in a continuous stream. In this 
 case no skimming can take place, but as the energetic boihng breaks the layer of 
 scums, this gets mixed up with the heavier deposits and does not interfere with 
 the proper subsiding in the setthng tanks. The latter are square iron vats, lined 
 with wood for retaining the heat, and provided with cooks at varying distances 
 from the bottom. The juice settles, the uppermost cook is opened and afterwards 
 the others, so that only the clear juice flows ofl and goes to the clarified juice 
 tank. Finally a cock at tBte bottom of the vat is opened, by which the scum 
 flows out and is run into the scum tank. 
 
 When the juice has a high density and the quantity of impurities is very 
 small, it often happens that the small amount of scum remains suspended and 
 does not settle in the heavy liquid, but the settling may be promoted in two ways. 
 Some pour cold water from an ordinary watering can upon the hot juice, which 
 dilutes the juice at the surface and causes it to throw down the impurities ; and 
 further a downward stream is produced by the cold water, which also imparts a 
 downward direction, to the scum. 
 
29 
 
 If the slow subsiding cannot be remedied by a longer stay in the olarifiers, 
 one can adopt the expedient of rendering the scum heavier and more flocculent, 
 which may be done by using a little more lime in tempering and at the same time 
 adding just the quantity of phosphoric acid necessary to again neutralize this 
 excess. The amount of lime remains the same, but a heavy, flocculent precipitate 
 of tribasic phosphate of calcium is produced, which envelops the fine particles of 
 scum, and carries them along with it to the bottom. 
 
 In recent years a third method of defecation has come into use, viz., 
 superheat clarification with continuous subsiding after Deming's method. The 
 limed juice is pumped subsequently through three vessels, in which it is heated 
 to over 110° C. under pressure, and afterwards cooled down to about 100° C, so 
 that the juice enters the apparatus at the ordinary temperature, is heated, 
 remains about 45 seconds at a temperatui-e of 110-115°0., and then leaves 
 it at a temperature of 95-100° 0. The three vessels consist of strong iron 
 horizontal cylinders, in which tubes of 2 in. diameter are fixed and connected 
 with each other by chambers at the front and back doors of the cylinders 
 in such a way that juice pumped in the tubes flows through them to and 
 fro with great velocity. Two of the vessels are called absorbers; the third, 
 having the largest dimensions, bears the name of digester. The cold juice is 
 introduced in the first absorber outside the tubes, and next through the tubes of 
 the second absorber, around which exhaust steam is admitted. Afterwards the 
 juice flows through the tubes of the digester, and is heated by fresh steam to the 
 temperature of 110-115° 0. required in this system, of clarification; finally it 
 passes through the tubes of the first absorber on its way to the settling tanis. 
 In this manner it imparts its superfluoiis heat to the fresh cold juice surrounding 
 title tubes, and heats it to 40-50° C. 
 
 Owing to the great velocity with which the juice is forced through the tubes 
 there is no fear of scaling inside ; in fact, they remain quite clean even after 
 some months' use. The apparatus requires only now and then a thorough 
 cleaning with hot dilute hydrochloric acid, in consequence of the outside 
 of the tubes in the first absorber becoming dirty with mud from the cane 
 juice. 
 
 The hot juice is conveyed into settling tanks, whence it is continuously 
 discharged. These tanks are cylindrical, vidth a conical bottom, carrying a wide 
 discharge tube provided with a cock. A great cone of sheet iron is suspended 
 in the cylinder; it is open both at the top and at the bottom, and its upper 
 diameter is smaller than the lower. The height of the cone is equal to that of 
 the cylinder, so that their upper edges are at the same level, and the bottom of the 
 cone is just at the same height as the conical under part of the settling tank, the 
 distance between the cone and the tank being at that place but slightly over 
 one inch. 
 
 The superheated juice flows into the tank outside of the cone, fills it and is 
 discharged through a wide tube ending high inside the cone. This arrangement 
 occasions a continuous downward current of juice outside, and one in opposite 
 direction inside the cone. The scum has therefore a tendency to sink to the 
 
30 
 
 bottom outside, and if it is induced to rise 'to the surface by the upward current 
 inside the cone, it knocks against its inclined side and sinks again. Oare should 
 be taken to always discharge so much subsided scums out of the funnel-shaped 
 bottom that no layer of dirt is formed between the edge of the cone and the 
 cylinder, as in that case great lumps of scum may be carried to the surface and so 
 spoil the clarified subsided juice. 
 
 In the case of slowly settling juice the same expedient may be used as 
 in the case of the ordinary clarification, i.e., rendering the precipitate heavier 
 by adding more lime and a corresponding amount of phosphoric acid to the 
 mill juice. 
 
 Ordinarily two settling tanks are required ; the juice flows first through the 
 smaller, afterwards through the larger one. 
 
 This system of clarification divides the juice continuously into clarified 
 juice, ready for evaporation, and into scum, which is conveyed to the scum 
 tank. 
 
 Each method of defecation has its advantages and its defects. The advantage 
 of the first method is that the juice is not heated to its boiling point ; hence steam 
 is saved, and, further, no danger of inversion or decomposition is to be feared. 
 A drawback, however, of this method is the great number of expensive defecation 
 pans it requires to contain the amount of slowly subsiding juice, if we wish to 
 get a properly clarified cane juice. 
 
 The common defecation pans with coils are easy to clean, which is not the 
 case with the pans in which the juice is boiled in tubes of small diameter, unless 
 a sufficient number of these are available, enabling us to dismount one for 
 cleaning, and go on working with the others. The skimming off of the light 
 floating impurities has the disadvantage of keeping the juice for a long time at a 
 high temperature, involving extra expenditure of steam, and it may cause 
 decomposition of a portion of the sugar. This danger, however, is not a very 
 serious one, as special experiments have shown that with skimming, the 
 evaporation of the juice did not exceed 3^, and with defecation, without skimming, 
 only 1'52, while in both oases the increase in quotient of purity amounts to O'^l, 
 showing that no perceptible loss of sugar had taken place. Against these 
 disadvantages must be set the gain of at once removing in the skimmings the 
 lighter portions of the scums, leaving therefore only the heavier, and hence more 
 quickly subsiding portion to settle in the settling basins, which saves much time, 
 and so increases the working capacity at this stage. 
 
 The advantages of the superheat clarification are saving of steam, labour, 
 and space, whilst the superheated juice subsides better than the simply heated 
 juice. A chemically definable difference between juice clarified by the two ways 
 of heating cannot be detected, as is shown by the tables underneath, where the 
 analysis is submitted of juice from cane of the same field, clarified in the same 
 factory, alternately one day by the usual clarification, and another day by 
 Deming's apparatus. 
 
31 
 
 First Day. 
 
 Variety of cane Cheribon. 
 
 Defecation process Old defecation. 
 
 Liming . . . . 4 to 4J litres lime 15° Beaume to 1000 litres juice. 
 
 First mill juice 
 Last mill juice . . 
 Mixed juice . . 
 Clarified juice . . 
 
 Syrup 
 
 Masse-cuite 
 First molasses 
 
 Brix. 
 
 Pol. 
 
 Quotient. 
 
 Glucose. 
 
 Glucose 
 ratio. 
 
 16-93 
 
 14-97 
 
 88-40 
 
 1-15 
 
 7-7 
 
 10-58 
 
 8-86 
 
 83-70 
 
 0-70 
 
 7-9 
 
 14-47 
 
 12-69 
 
 87-70 
 
 0-98 
 
 7-7 
 
 14-87 
 
 13-21 
 
 88-90 
 
 090 
 
 7-4 
 
 50-59 
 
 44-90 
 
 88-70 
 
 2-90 
 
 6-5 
 
 91-72 
 
 81-22 
 
 88-50 
 
 5-88 
 
 7-2 
 
 79-52 
 
 49-20 
 
 61-86 
 
 14-24 
 
 
 Second Day. 
 
 Variety of cane Cheribon. 
 
 Defecation process Deming's superheat clarification. 
 
 Liming i^ litres to 1000 litres juice. 
 
 Erix. 
 
 Pol. 
 
 Quotient. 
 
 Glucose. 
 
 Glucose 
 ratio. 
 
 First mill juice 
 Last mill juice 
 Mixed juice . . 
 Clarified juice . . 
 Syrup . . 
 Masse-cuite 
 First molasses 
 
 17-35 
 9-02 
 14-55 
 14-72 
 37-98 
 90-30 
 80-92 
 
 15-27 
 7-70 
 12-55 
 12-67 
 33-40 
 80-12 
 50-60 
 
 88-00 
 85-30 
 86-20 
 86-10 
 87-90 
 88-70 
 62-54 
 
 1-24 
 0-60 
 1-00 
 0-94 
 2-58 
 6-05 
 16-25 
 
 8-0 
 7-8 
 8-0 
 7-4 
 7-7 
 7-5 
 
32 
 
 Thied Day. 
 
 Variety of cane Muntok. 
 
 Defecation process Old defecation. 
 
 Liming 4 to 4 J litres to 1000 litres juice. 
 
 Brix. 
 
 Quotient. 
 
 Glucose. 
 
 Glucose 
 ratio. 
 
 Pirst mill juice . 
 Last mill juice 
 Mixed juice.. 
 Clarified juice . . 
 
 Syrup 
 
 Masse-cuite 
 First molasses . 
 
 18-70 
 9'30 
 16-10 
 16-53 
 45-72 
 92-00 
 79-6 
 
 16-88 
 7-84 
 14-23 
 15-00 
 41-2 
 82-94 
 50-8 
 
 90-3 
 
 84-3 
 88-4 
 90-8 
 90-1 
 90-2 
 63-8 
 
 1-24 
 0-57 
 1-03 
 0-99 
 2-56 
 5-42 
 14-80 
 
 7-4 
 7-3 
 7-2 
 6-6 
 6-2 
 6-0 
 
 FOTIETH DaT. 
 
 Variety of cane . . . . Muntok. 
 
 Defecation process . . Deeming's superheat clarification. 
 Liming 4-2 litres to 1000 litres juice. 
 
 
 Brix. 
 
 Pol. 
 
 Quotient. 
 
 Glucose. 
 
 Glucose 
 ratio. 
 
 First mill juice 
 
 18-71 
 
 16-72 
 
 89-40 
 
 1-53 
 
 9-1 
 
 Last mill juice 
 
 10-70 
 
 902 
 
 84-30 
 
 0-84 
 
 9-3 
 
 Mixed juice 
 
 16-92 
 
 14-71 
 
 87-00 
 
 1-37 
 
 9-3 
 
 Clarified juice 
 
 16-67 
 
 14 69 • 
 
 18-10 
 
 1-21 
 
 8-2 
 
 Syrup 
 
 40-7 
 
 36-40 
 
 89-40 
 
 3-02 
 
 8-3 
 
 Masse-cuite 
 
 91-4 
 
 80-51 
 
 88-10 
 
 6-63 
 
 8-2 
 
 First molasses 
 
 79-8 
 
 48-80 
 
 61-03 
 
 16-00 
 
 
 2. Treatment of the Olaeieied Juice. 
 In many factories the juice is pumped off after settling, without any further 
 treatment, into the suction-tank of the evaporators, in others it passes through 
 one or another form of juice filter, while yet in others it is once more boiled in 
 eliminating pans of the same shape as has been previously described. This 
 treatment is especially necessary for juice clarified by the first-named method, as 
 in that case a great part of the scums very often accompany the clarified juice 
 owing to want of attention. The juice, after settling, is boiled, skimmed, and if 
 
33 
 
 necessary, rendered neutral by phosphoric or sulphurous acid if the juice is too 
 alkaline, or with soda or lime if it is too acid, because, as already mentioned, a 
 neutral or very slightly acid or alkaline juice is the most advantageous. 
 
 Juices ■which have been allowed to settle in special clarifiers do not need 
 eKmination, for in this case the juice can be neutralized directly in the 
 defecation pans. 
 
 If the juice is too acid a solution of caustic soda or carbonate of soda of 20° 
 Beaume is used, so much being taken, in the case of " non-chemical sugar," as 
 ■will result in a slightly alkaline reaction of the juice with sensitised litmus paper. 
 If, on the other hand, the juice is too alkaline or neutral and it is intended to 
 make high-class sugar, the juice is rendered faintly acid with a solution of 
 phosphoric acid of 20° Beaum6, or a stream of the vapour of sulphurous acid is 
 conducted into the juice until the proper acid reaction is obtained. 
 
 3. Tbeatment of the Sctjms. 
 
 The scums from the clarifiers or from the settling tanks are run into the scum 
 tanks as already mentioned. Sometimes the scums are allowed to settle once 
 more, and the clear juice is again di-awn off, but generally the scums are mixed 
 with lime and steamed to promote filtration. Many factories only possess a single 
 scum tank, into which the sc^um continually flows from the clarifiers ; it is heated 
 and limed from time to time, and pumped ofP to the filters, but in this way it is 
 impossible to know whether the scum is sufficiently limed or not. It is much 
 better to have two tanks, and use them alternately, so that the first is filled, 
 properly lim^ed, steamed and emptied, while the s,econd is being filled. Instead of 
 this, a mixer can be put in front of the steaming tank in which the scums are 
 limed, and then run into the tank. 
 
 If the defecation has been cai'ried on ■with sufficiently tempered juice at a 
 
 proper temperature the scums can be filtered without addition of lime ; this agent 
 
 is however a powerful help if owing to circumstances the clarification has been 
 
 defective. 
 
 n. Cakbonatation. 
 
 While it is advisable to avoid an excess of lime iu defecation, the carbona- 
 tation process, on the contrary, requires it. Here the juice is mixed ■with a large 
 excess of lime, during which operation the temperature should not exceed 60°, 
 and afterwards the excess of lime is removed by a stream of carbonic acid. The 
 action of the lime is here somewhat different from that in defecation ; it precipi- 
 tates albumen and gums, but, in addition, in its conc3ntrated state it also attacks 
 glucose, and transforms it into organic acids. We have already seen, in speaking 
 of the defecation process, that when this action of the lime takes place at the 
 temperature of boiling juice, the lime salts are dark coloured, viscous, and very 
 troublesome, but it the lime acts upon glucose at temperatures below 60°, the 
 lime salts then produced are partially insoluble, and easy to be removed, the 
 remainder being colourless, very soluble and stable bodies, giving no trouble 
 whatever. Moreover the juices become very light in colour, are clear, easily 
 filtered, evaporated, and boiled, as ■with the great excess of Ume more of the 
 gummy matter is thrown down than in simple defecation, as is shown by the 
 f ollo^wing table : — 
 
34 
 
 Brix. 
 
 Mill juice 18-4 
 
 MiU juice, clarified by 
 
 defecation 
 Mill juice, clarified by ) 
 
 Sucrose. 
 
 G-lucose. 
 
 Pectine. 
 
 Glucose 
 per 100 
 Sucrose. 
 
 Quo- 
 tient of 
 purity. 
 
 15-72 
 
 . 0-92 . 
 
 . 0-634 
 
 .. 5-9 . 
 
 . 85-6 
 
 18-6 
 
 16-9 
 
 15-99 
 
 14-65 
 
 0-95 .. 0-292 
 
 0-44 
 
 0-142 
 
 5-9 
 
 3-0 
 
 86-1 
 
 86-7 
 
 carbonatation . . . . j 
 
 As soon as the Hme has finished its purifying action, the excess is removed 
 by carbonic acid, which combines with the lime and forms insoluble carbonate of 
 calcium. This saturation may be efiected in one or in two operations, and 
 according as this is done the process may be distinguised by the name of single or 
 double carbonatation, the difference being as follows : — 
 
 On treating cane juice with an excess of lime at a temperature between 55° 
 and 60° C, besides the already-mentioned pectine, gum, and albumen, a, basic 
 lime salt of an organic acid derived from the glucose, probably a basic glucinate 
 of lime, is thrown down. This salt is dark coloured and liable to spontaneous 
 decomposition, but so long as it remains in an alkaline medium at the said 
 temperature it is insoluble, and can be removed by filtration . If therefore the 
 carbonated cane juice is filtered at the time when the great bulk of the lime is 
 already precipitated by the carbonic acid, but the juice is stUl alkaline, and the 
 temperature does not exceed 60° C, we get a very light coloured juice, and the 
 basic salt passes over into the scums. The juice is afterwards neutralized by 
 carbonic acid, and thus all trace of alkalinity is removed without any particle of 
 the first precipitated lime salt getting again dissolved in the neutral juice. This 
 is done by double carbonatation, but if we saturate the limed juice in one 
 operation, causing the basic glucinate to come into a neutral liquid, it changes 
 into the soluble normal glucinate, which colours the juice again. Double 
 carbonatation therefore is apt to yield more completely clarified juice than the 
 single process, while some other points of difference will be mentioned afterwards. 
 
 The difference is also clearly shown be the analyses of the scums obtained by 
 the two operations, of which the figures follow here : — 
 
 Filter-presB cakes 
 
 from single 
 
 Carbonatation. 
 
 3-90 
 
 Constituents. 
 
 Sucrose 
 
 Glucose 
 
 Cane fibre 
 
 Wax 
 
 Organic acids 
 
 Albumen 
 
 Gums 
 
 Total organic substances 
 
 Carbonate of calcium . 
 Carbonate of magnesium 
 Iron oxide and alumina . . 
 Phosphoric acid 
 
 3-08 
 3-43 
 1-94 
 2-55 
 1-11 
 
 16-01 
 
 . . 67-94 
 
 1-80 
 
 .. .. 2-41 
 
 0-71 
 
 Silica 8-48 
 
 Sand and clay 2-48 
 
 Undetermined inorganic substances. . 0-17 
 
 Total inorganic substances . . 83-99 
 
 Filter-press cakes from 
 
 double Carbonatation. 
 
 1st saturation. :jnd saturation. 
 
 10-10 . 
 
 8-10 
 
 0-38 . 
 
 . — 
 
 6-10 . 
 
 0-50 
 
 2-48 . 
 
 — 
 
 2-12 . 
 
 . . 4-20 
 
 2-72 . 
 
 — 
 
 1-20 . 
 
 — 
 
 25-10 . 
 
 .. 12-80 
 
 61-94 
 
 .. 85-01 
 
 1-21 . 
 
 . . 0-10 
 
 4-66 . 
 
 0-51 
 
 0-87 . 
 
 .. 0-12 
 
 1-85 . 
 
 . . 0-64 
 
 4-37 . 
 
 _ 
 
 — 
 
 . . 0-82 
 
 74-90 . 
 
 . . 87-20 
 
35 
 
 The carbonatation takes place ia large square iron basins, ■which sometimes 
 are open, but in most oases are covered with an iron plate provided with a lid, 
 permitting samples of the contents to be taken from time to time, and allowing 
 entrance to the basin for cleaning it. A chimney is also fitted to it to carry off 
 the escaping gases. A ooU is further fitted in the carbonating basin, into which 
 steam can be admitted, and a perforated iron coil or cross for the carbonic acid. 
 
 The basin is half filled with the heated juice, then the proper quantity of 
 lime is poured in, and the supply of carbonic acid turned on, while care is taken 
 that the temperature shall not exceed 55° to 60° 0. As already stated, dark 
 coloured lime salts are produced at a higher temperature, and at a lower 
 temperature the action of the carbonic acid (saturation) proceeds too slowly, 
 causing loss of time and of carbonic acid. 
 
 During the saturation the juice froths violently, for which reason the basin 
 is only half filled, and for the same reason the lid should be kept closed. If 
 notwithstanding this the juice still foams over between the lid and the plate, a 
 little oil should be poured on it or the froth should be blown down by a jet of 
 steam. 
 
 1. — Single Cabbonatation. 
 
 The carbonic acid is admitted to the juice until a sample of it only gives a 
 faint pink reaction on phenolphthalein paper, and the supply is then slowly shut 
 off, resulting in the juice being just neutral. It is afterwards heated by the 
 steam coil up to 90° C, and filtered through filter-presses, or if the heating of 
 juice containing such a large quantity of scum should be too difficult, the 
 saturated juice may be run off into settling tanks. The clear juice, which is 
 obtained immediately, ia syphoned off, the scum steamed with direct steam, and 
 then filtered. The quantity of lime necessary for this operation is entirely 
 regulated by the running of the filter-presses ; the precipitate from the juice is 
 rather viscous, and is very difficult to filter, therefore carbonatation aims at 
 mixing it with so much carbonate of lime, that the mixture can be easUy filtered. 
 If the filter presses run badly before the chambers are full of scum, the quantity 
 of lime added to the juice should be increased, and as an excess of lime is 
 perfectly harmless in this process we can safely go so far as to use too much, 
 because the carbonic acid is certain to neutralize it. We may, therefore, go on 
 for a long time with one fixed quantity of lime and not have to put up with the 
 inconvenience met with in the defecation process, occasioned by the difference in 
 quality of the juice of canes from various fields. The quantity of lime required 
 is about one per cent, of the weight of cane, and the amount of glucose diminishes 
 during the process to from 25 to 40 per cent, of the original quantity. In order 
 to avoid the large volume of water added to the juice in the Hme cream, which 
 has to be evaporated again, some have attempted to apply the lime unslaked. A 
 practical way of doing this has, however, not yet been found out ; unslaked lime 
 in pieces is not to be recommended, because of its causing a rise in temperature, 
 and hence increasing the risk of decomposing the glucose and colouring the juice. 
 Dry slaked Ume becomes covered with a layer of precipitated impurities as soon 
 as it is put into the juice, thus preventing its further action. 
 
36 
 2. — Double Oarbonatation. 
 
 Ooutinuous exammation of the juice during the saturation stows that at the 
 beginning it remains liquid, but gradually thickens in consequence of the 
 gelatinous precipitate, which does not settle. After the admission of more 
 carbonic acid, there is a point at which the precipitate settles rapidly and leaves a 
 bright coloured, clear, alkaline liquid, with an alkalinity of about O'Oo^ OaO. 
 With the single carbonatation process this alkalinity is likewise neutralized, with 
 the consequence, already mentioned, that the juice again assumes a darker 
 colour, but with double carbonatation the juice is filtered aud the precipitate 
 removed. 
 
 For the reason already mentioned, this filtration ought also to be performed 
 at a temperature not exceeding 60°, as with a rise in temperature the coloured 
 salt also becomes dissolved. Great care should be taken to stop this first 
 saturation at the exact point when the precipitate settles well, while the juice 
 is still alkaline; if it is stopped too early the juice does not filter well; and 
 if it is allowed to go on too far, the juice becomes coloured owing to the solution 
 of the normal gluoinate of lime. 
 
 The filtered alkaline juice is pumped into other saturation tanks, which are 
 also fitted with coils and pipes for steam and carbonic acid, but which may be 
 filled to the brim, as in these the juice no longer froths. A slight quantity of 
 lime is added, and saturation repeated up to neutrality ; then the juice is boiled 
 to break up bi- carbonates, and again filtered through filter-presses. 
 
 Just as with single carbonatation, in this case also the quantity of lime is 
 regulated by the filter-presses. As the juice is now filtered at alow temperature, 
 and in that case the precipitate from the juice is still more difficult to deal with 
 than at a more elevated one, a still greater quantity of lime is required to obtain 
 good hard filter-press cakes, and hence double carbonatation requires more 
 carbonic acid and also more lime than the single process. 
 
 When we see by the slow filtration that the precipitate is too viscous, then 
 the quantity of lime must be increased, and in this case also a maximum may be 
 used, because the excess is in like manner neutralized by the acid. As a rule we 
 go as far as IJ^ of the weight of cane, and the amount of glucose falls as low as 
 from 20 to 50^ of the quantity originally present. A portion of the acids fornaed 
 is separated by filtration as a basic lime salt, but the greater part remains in the 
 juice as lactate and saccharinate of lime, causing a large increase in the quantity 
 of lime salts in cane juice by carbonatation. In many cases it is impossible to 
 obtain quite neutral juices by saturation with carbonic acid, as either the lime or 
 the juice contains alkali, which becomes carbonate and thus keeps the juice 
 alkaline after saturation also. In order to prevent this, and also with a view of 
 obtaining a still further decoloration, a third saturation, this time with sulphurous 
 acid, is sometimes used in factories working with the double carbonatation 
 process. To this end the saturated juice is pumped into eliminating pans, and 
 sulphurous acid gas is let in, till the juice is neutral with turmeric paper, and 
 remains so after being boiled, after which it is filtered through a juice filter. 
 Great care is recommended in this operation, for an excess of sulphurous acid is 
 very injurious, as will be shown later on. 
 
37 
 
 Abvaktages and Defects of the Different Methods. 
 The advantages of carbonatation are — 
 
 1. The clarification of the juice is more effectual, because the viscous 
 gummy matters are precipitated and a part of the glucose is transformed into 
 harmless combinations. 
 
 2. The clarified juice is brighter and more easy to work up. 
 
 3. The clarification is effected in one single operation ; imm.ediately after 
 saturation the liquid is divided into a clear juice, easy to filter, and a scum which 
 settles well, while with the defecation process we are troubled with slowly settling 
 and badly filtering scums, and a slimy, opalescent juice. 
 
 4. Independently of the kind of cane crushed, we can employ a like quantity 
 of lime for a long time at a stretch, because if an excess of lime has been used, 
 the carbonic acid neutralizes it afterwards, while the quantity of lime required 
 to be used in defecation is very variable if canes from two different fields are 
 crushed together, and therefore one is not sure of using it in proper quantity, 
 which is a very important point in this operation. 
 
 5. Owing to the carbonated juice being purer, brighter, and more easily 
 worked, the quality of the sugar is better than from a like kind of juice clarified 
 by the defecation process. 
 
 Against these advantages must be set certain drawbacks, the chief of which 
 is the greater expense, because more lime is required, and moreover the cost of 
 the lime-kiln and fuel, together with that of the carbonic acid pump and further 
 plant, increases the cost price of the sugar. 
 
 Further, the work connected with the lime-kUn requires continuous attention ; 
 it often occurs that either the lime is burnt at a too high or a too low temperature, 
 or that the quality of the gas is deficient, and there are other drawbacks that we 
 have not to put up with in the defecation process. 
 
 In these times, when almost exclusively so-called " non-chemical " sugar or 
 refining crystals are made, it is not advantageous for most factories to use 
 carbonatation. If, on the contrary, we want to make sugar for direct consumption 
 then everything apt to cause coloration should be avoided, and we must have 
 recourse to the double carbonatation process. This requires much lime and 
 carbonic acid, and thus causes considerable expense, but this is more than 
 compensated for by the higher price which sugar for direct consumption fetches 
 when compared with raw sugar. 
 
 in. — Other Clarifying Agents. 
 
 Besides lime, certain other agents are occasionally used for the purpose of 
 removing impurities from the juice. The principal of these are : — 
 
 1. Phosphoric Acid. — This is commercially known either as a solution of 
 the pure acid or as combined with lime in the form of superphosphate or acid 
 phosphate of calcium. It is used for neutralizing an excess of lime, and to this 
 end it is added during the elimination of the defecated or carbonated juice ; or it 
 
38 
 
 serves during defecation to cause slowly settling precipitates to sink to the 
 bottom, and therefore is added to the juice during clarification together with 
 an equivalent quantity of lime, when the floooulent precipitate of tribasic 
 phosphate of lime carries the impurities to the bottom. Phosphoric acid may 
 also be used for breaking up lime salts, but for this purpose it is more profitable 
 to use the pure acid than the acid phosphate,' and afterwards good care must be 
 taken to neutralize the juice with soda. Ordinarily the phosphoric acid is applied 
 in solution of a density of 20° Beaum^e. 
 
 2. Sulphurous Acid. — Sulphurous acid, which in most cases is prepared by 
 burning sulphur in an iron oven, is much cheaper than phosphoric acid, and 
 hence its use is more widely prevalent in sugar manufacturing than that of the 
 other acid. It has, moreover, the further advantage of also exercising a bleach- 
 ing action on the cane juice. This latter point should, however, not be too much 
 relied upon, as the action only becomes evident when the juice is acid, and is 
 besides very unstable, the sugar becoming dark after being cured and delivered. 
 Siilphurous acid claims the further advantage of promoting the crystallization of 
 the after products and of diminishing the viscosity of the molasses in conse- 
 quence of its breaking up lime salts, though the direct scientific proof of this 
 decrease in viscosity has as yet not been adduced. 
 
 This agent is applied in various ways in diSerent factories ; in some, fum.es 
 are pumped or drawn by suction into the raw mill juice, in others, into the 
 defecated but not yet settled juice ; others, again, apply it to the clarified juice, 
 which is eliminated with its addition, and finally others treat the syrup with it. 
 Being an inorganic acid, it possesses the property of precipitating the albumen 
 in the mill juice and thus facilitating filtration ; it further temporarily bleaches 
 the juice. Applied to the clarified juice it will neutralize too great alkalinity, and 
 precipitate lime salts ; in this case it is advisable to use it exclusively in the 
 elimination of already clarified juice, and to stop the supply before the juice has 
 become acid, as when this takes place the tubes of the evaporators become too 
 heavily incrusted. When making white sugar, intended for direct consumption, 
 we ought also to be very cautious with the sulphurous acid, for if the juice is 
 allowed to become acid it is bleached, but if afterwards the molasses are not 
 completely removed from the crystals, which cannot be seen by the eye because 
 of their being colourless, the dark colour comes back on contact with the air, and 
 the sugar assumes a dark tinge which diminishes its value. 
 
 Acid sulphite of soda or of lime has a, similar action to that of sulphurous 
 acid, and also the advantage of breaking up lime salts without causing injurious 
 acidity. 
 
 The greatest drawback of sulphurous acid and its salts is the liability of 
 their becoming oxydized and converted into sulphuric acid, which with the lime 
 constantly present forms gypsum (CaSO J, causing incrustations in the tubes of 
 the evaporators and on the coils of the vacuum pans. 
 
 3. Eydrosulphurous Acid. — This acid is obtained by the action of zinc or tin 
 powder on sulphurous acid, which is thereby reduced to hydrosxilphurous acid 
 (H,SOJ. 
 
39 
 
 This acid has a much stronger bleaching action than has sulphurous acid, 
 and may render good service in the manufacture of refined sugar. 
 
 The inventors advise one to introduce the metallic powder and the sulphurous 
 acid into the syrup. As after the treatment the syrup still contains very finely 
 divided metallic powder, it is absolutely necessary to filter it before being boiled 
 into sugar, because of the poisonous properties of zinc. The cane syrup from 
 juice clarified by the defecation process is, however, still so slimy that it will jiot 
 pass through filter cloth, which disagreeable property is a serious impediment to 
 the process. 
 
 4. GausUc Soda and Carbonate of Sodium. — It happens in many cases that 
 cane juice still has an acid reaction, although sufficient lime has been added to 
 precipitate all impuiities. It is not advisable to evaporate such acid juices, and 
 therefore they should be neutralized, which may be effected during defecation or 
 afterwards on elimination of the settled juices. Until a few years ago, lime was 
 exclusively used for this neutralization, but as lime salts always cause more 
 trouble during the further operation than soda salts, soda has been adopted for 
 this purpose. For purifying purposes lime is, of course, the indispensable agent. 
 
 Some use a solution of caustic soda of 20° Beaum6, but others prefer a 
 solution of Solvay soda of the same concentration. This disadvantage of the 
 carbonate (Solvay Soda) is that it efiervesces on coming into very acid juice, but 
 this is counterbalanced by the advantages of being cheaper, more easily handled, 
 not attacking the hands and clothes of the workmen, and not causing any 
 alkaline reaction if by chance it is used in excess, as caustic soda does, but only 
 precipitating a little m^ore lime from the juice, which remains neutral. 
 
 5. Barytes. — This agent has frequently been recommended as a universal 
 clarifying substance, and though it is true that it precipitates from the juice 
 some products of the decomposition of glucose, forming with them salts of 
 baryta, these combinations are by no means completely insoluble, causing the 
 juice thus treated to contain always a certain amount of poisonous material, so 
 that, as a rule, the use of barytes should be condemned. 
 
 6. Chloride of Aluminium, Chloride of Zinc, Chloride of Calcium, Sulphate 
 of Aluminium, &c. — All these salts have successively been used in clarification 
 for the purpose of precipitating the scum, but none of them has proved successful, 
 because too much of them is needed to produce any tangible effect, and so they 
 have all gone out of use again. 
 
 IV. — Filtration. 
 
 In sugar factories we meet with two different kinds of filters, viz., juice 
 filters, for the filtration of juice, and scum filters, in which the juice is separated 
 from the scums. Bone black filters are very seldom used in raw sugar factories, 
 though they are indispensable in making sugar for direct consumption. 
 
 Juice Filters. 
 
 The simplest form of juice filter consists of a bag made of cloth, into which 
 the juice is poured, the clear juice passes through and the impurities are kept 
 back. Such filters are the "Puvrez" filters, consisting of a cylindrical bag, of 
 
40 
 
 ■wrliicli one end is closed and the otter tied round a pipe supplying the juice to be 
 filtered, which enters into the bag under a certain pressure. The impurities are 
 kept back, and the filtered juice passes through the cloth and flows into an iron 
 gutter to which the bag is fixed, and so is conveyed to the suction tank of the 
 evaporators. A great inconvenience of this filtration from inside to outside is 
 that the finer impurities also are driven between the pores of the cloth and choke 
 them up, so that the bag does not filter a long time before becoming full of scum, 
 and has to be changed. This has been the reason why filters of this description are 
 now generally abandoned, and other systems have been adopted in which the 
 filtration takes place from outside to inside. 
 
 In these systems the filter consists of a square iron vessel on which an iron 
 plate is screwed as a cover. In this vessel are a certain number of chambers 
 lined with cloths, kept apart by perforated plates or metal spirals fitted in the 
 chambers. Each chamber is therefore shut off by cloth at the sides and at the 
 bottom, and the upper edges are pressed tightly together, thus preventing the 
 juice, with which the filter is filled, from entering the chamber before having 
 passed through the cloth and left behind its impurities. Each chamber has a 
 spout for the discharge of the filtered juice, and a large cock at the bottom of the 
 filter enables the workman to empty the whole of the contents when it has to be 
 cleaned. When starting, the chambers are supplied with new or clean cloths, 
 the filter is closed by the cover, the screws are tightened, and the hot juice is 
 , admitted at a pressure of three to six feet, avoiding great variations. The juice 
 passes through the cloth, leaving behind the suspended particles, which sink to 
 the bottom of the filter, and do not interfere with the filtration through the cloth. 
 This can therefore be used for a long time, but when it is dirty it is changed for 
 a new cloth, and as soon as the contents of the entire filter have become too 
 muddy because of the impurities deposited, it is emptied by means of the cock at 
 the bottom ; the juice is conveyed to the scum tank, the filter is washed and is 
 ready for use again. 
 
 In many cases the fioating impurities of the juice are so fine that filter cloth 
 is unable to retain them; therefore, bagasse is sometimes used as a filtering 
 material. Bagasse from the second mill is preferred, that from the first being 
 too coarse, and that of the third too much crushed and dusty. 
 
 The bagasse is put in a square iron box, covered with a lid which is screwed 
 on it. The juice is introduced below, under a pressure of some 4 or 5 feet, forces 
 its way through the bagasse and leaves the filter by a spout or tube just under 
 the rim of the box. The bagasse is therefore constantly kept covered by hot 
 juice, which prevents it getting sour, but promotes the extraction of gummy 
 matter by the hot alkaline juice. When the bagasse is saturated with scum or 
 dirt, it is transported to the mill, which extracts the juice with which the bagasse 
 is imbibed, thus suppressing all loss of saccharine matter which is incurred in the 
 other system by the washing of the dirty filter cloths. The hot steaming 
 bagasse is, however, a difficult material to deal with, besides which the carrying of 
 clean and dirty bagasse to and from the mill through the whole factory is a 
 rather unsesthetio operation. 
 
41 
 
 Scum Filters. 
 
 The oldest form, of scum filter is the " Taylor " filter, -which is still used in 
 several factories. It consists of a numher of long narrow double bags, closed at 
 the lower end, suspended in an iron case fui'nished with a receiver for the scum. 
 Into the bottom of this receiver are screwed several rows of mouth-pieoes, round 
 which the above-mentioned bags are tightly fixed. The receiver being filled 
 with the scum, the latter runs into the bags, which retain the impurities, while 
 the clear juice is filtered ofi and flows into the lower part of the apparatus, from 
 which it is conducted by a gutter to the suction tank of the evaporators. 
 
 The front side of the apparatus is provided with a door so as to allow the 
 bags to be changed. When these are full, and no more juice flows ofi, they are 
 detached from the mouth-pieces, tied round the top, pressed, emptied, and 
 washed. As the filtration proceeds from the inside outwards the same 
 inconvenience is met with as in the " Puvrez" filters, though not in so great a 
 degree, as the pressure is much less and the scum more compact. The 
 disadvantage, that owing to. the great surface of bags exposed to the air the juice 
 cools very rapidly, and hence does not filter so quickly, or even becomes easily 
 acid, can be remedied by blowing a constant jet of exhausted steam, into the 
 chamber, which keeps up the temperature, prevents sourness, and increases the 
 capacity by 20 per cent. 
 
 In place of these filters most factories now use fllter-'pressea ; which consist 
 of metal chambers lined with cloth, and screwed tightly one against the other 
 A pump or monte-jus, or air compressor, fills them, with the hot scum. The 
 juice passes through the cloth and escapes through suitable channels, while the 
 solid matter remains behind in the form of hard cakes. As every chamber has 
 its own spout, which can be closed by a cock, any chamber can be stopped 
 if the filtered juice should be turbid owing to a hole or leak in the filter 
 cloth. 
 
 The scum should enter into the filter-press as hot as possible, having an 
 alkaline reaction and at a pressure of from \^ to 2 atmospheres. When the 
 chambers are full of scum-cake, as indicated by the fact of no more juice flowing 
 off, the supply of scum is stopped, the cakes ai-e washed with water or steam, the 
 press opened, and the cakes removed. The cloths are changed if they have 
 become too dirty, after which the press is again closed by a screw and is ready 
 for further use. 
 
 The washing of the filter-press cakes is only applicable in factories using the 
 carbonatation process, because the scums obtained by defecation are much too 
 slimy to allow their being washed out in the press. The steaming of the scums 
 merely has the effect of driving the superfluous juice from between the particles 
 of the cakes, it does not dilute the juice with which the scum is intermixed. 
 
CHAPTER IV. 
 
 Concentration of the Jtjice. 
 
 Up to tlie point now reached, all the operations the cane juice has undergone, 
 from the moment it left the mills, have had for their object the removal of the 
 non- saccharine matters. It will, however, always be impossible to totally 
 eliminate these foreign matters, and hence no completely pure solution of sucrose 
 can possibly be obtained. The purpose of the operations next following is 
 therefore to bring over the sugar in a solid state ; to separate it in a crystallized 
 form from the impurities which remain dissolved in the mother-liquor or 
 molasses. This object is attained by evaporating the water of the juice, and 
 allowing the sugar to crystallize under such circumstances that the maximum of 
 sugar crystallizes out in the purest state possible, and in such a shape that it can 
 easily be separated with a minimum of loss. As sugar is very liable to 
 decomposition and deterioration when occurring in solution, the first and most 
 necessary consideration is to carry on all operations, from the crushing to the 
 boiling, as rapidly as possible, and without the least delay. 
 
 The concentration of the juice is ordinarily effected in two stages, viz., 
 evaporation, which concentrates the juice to a syrup containing about 50 per cent, 
 of solid matter, and hmling, which concentrates this syrup still further, and 
 transforms it into a ci"ystalline mass, containing only from 6 to 8 per cent, of 
 water. Between these two stages, the syrup is in most cases subjected to a 
 second clarification, the successful application of which is of great importance. 
 
 1. Evapobation. 
 
 Formerly the clarified juice was evaporated in shallow pans, known as the 
 " Copperwall," over an open fire, but this process had the inconvenience of very 
 imperfectly utilizing the effect of the fuel, so that a great deal of the latter was 
 wasted, and it was also impossible to prevent local overheating, which caused a 
 portion of the sugar to become decomposed. As the pans were open, and' floating 
 impurities were constantly skimmed off, the mechanical purification was a very 
 good one, but this trifling advantage could not counterbalance the enormous 
 losses of sugar and fuel caused by the evaporation over an open fire. 
 
 Later on, the juices were evaporated in concretors, i.e., open pans, heated by 
 steam, which secured a more economical utilization of the fuel, and avoided the 
 risk of overheating, but they too were soon supplanted by the multiple-eflet 
 apparatus. In these the juice boils m vacuo, and therefore at a lower temperature, 
 at which inversion is practically no longer to be feared, and m.oreover the employ- 
 ment of two, three, or even foiu- vessels consecutively, allows the heat of the 
 steam to be utilized for evaporation as completely as possible ; the vapour from 
 the first vessel passes into the steam drum of the second, that from the second 
 heats the juice in the third, and so on, as will be seen from the following 
 description. 
 
43 
 
 The evaporating vessels most generally in use consist of a large iron cylinder, 
 with a dome-shaped head, fitted with a wide tube, which carries off the vapours. 
 The lower part of the cylinder is divided into three portions, the lowest of which 
 is only very shallow, by two transverse plates pierced with round holes, in which 
 are fitted tubes which bring into communicatipn the upper and the lower portions 
 of the cylinder, called together the juice-chamber. The middle portion is called 
 the steam-drum, and is traversed by the tubes, but does not communicate with 
 them. The steam-drum is provided with a supply pipe for exhausted steam, and 
 in most cases with a smaller one for fresh steam, and also with an escape pipe for 
 the condensed water. The wide tube which carries off the vapours from the juice 
 is so constructed as to prevent the particles of the juice from passing ofi with 
 the vapovirs, and ends in the steam-drum of a second similar vessel, and so on, 
 while an air-pump is attached to the pipe carrying ofl the vapour from the last 
 vessel, which draws them ofl and condenses them. The steam-drums are also 
 emptied by means of pumps. 
 
 In the case of a triple-eflet, supposing all the vessels to be fiUed with juice, 
 the following is what takes place when steam is admitted to^ the steam-drum of 
 the first vessel : — 
 
 The steam, having a temperature of over 100°, causes the juice in the first 
 vessel to boil, and becomes condensed itself. The vapours from the juice enter 
 into the steam-drum of the second vessel and heat the juice contained in the 
 juice-chamber, where it is under a certain vacuum, and therefore boils at a lower 
 temperature than in the first vessel. The vapour formed here is easily capable of 
 heating to boiling point the juice in the third vessel, because this boils in a space 
 which is in immediate communication with the air-pump and the condenser. The 
 vacuum is therefore greatest in the last vessel, and least in the first, and conse- 
 quently the juice in the last vessel boils at the lowest temperature. 
 
 The draining ofi of the condensed water- from the steam-drum of the first 
 vessel is effected by a syphon tube of about 15 feet in height, measuring from 
 the lowest tube-plate, while the water of the second and third vessels is removed 
 by a pump, if it is to be used again for feeding the boiler ; in the contrary case 
 the steam-drums are simply connected with the air-pump. The steam-drums are 
 therefore always kept clear both from water and from incondensable gases, and 
 as the vapours from the juice in the preceding vessels are immediately condensed 
 by the cold juice, they cause a vacuum in the juice-chambers of the first and 
 second vessels. 
 
 The clarified juice is pumped into a tank, from which it flows into the first 
 vessel by its own weight, or is pimiped into it if the fii-st vessel is worked under 
 pressure. It enters underneath into the juice-chamber, where various arrange- 
 ments are made to facilitate the free mixture of the fresh juice with the juice 
 already present in order to ensure a good circulation. The vessels are connected 
 with one another by means of pipes provided with valve cocks. By the cautious 
 opening of these cocks the juice is sucked from the first vessel into the second, 
 and from there into the third, because of the difference in vacuum of the three 
 vessels ; in this way the clarified juice enters into the system, and leaves it with 
 
44 
 
 the concentration of syrup. A proper regulation of the cocks permits the supply 
 of juice to equal the evaporation, so that the concentration goes on steadily 
 without changing the position of the valves. 
 
 When working with the triple-effet we have to take care to keep only such 
 quantity of juice in the first vessel for the upper tube-plate to be just covered by 
 the juice in full ebullition ; if the hot tubes are not constantly moistened by the 
 spattering juice, overheating is to be feared, and if the vessels are too full we run 
 the risk of losing juice by its passing off with the current of vapour as it leaves 
 the vessel. These rules are also applicable to the other vessels, Ijhough with them 
 the danger of overheating is not so great. In case they are insufficiently filled, 
 they should be supplied from the other vessels ; in the contrary case, the supply 
 is stopped, but the syrup is only drawn off when it has the required specific 
 gravity. 
 
 In order to avoid considerable loss of syrup, it is advisable to have a 
 separator between the last vessel and the air pump. This is usually a cylindrical 
 vessel, provided with perforated diaphragms which slacken the speed of the 
 vapour and compel it to part with the drops of syrup it carries along. The 
 recuperated syrup collects on the bottom and flows back into the last vessel by 
 means of a discharge tube. 
 
 If the condensed vapour is to be used for feeding the boilers, good care should 
 be taken to prevent its containing any sugar from juice spattering over, as this 
 has a very noxious effect on the boiler plates ; it is therefore necessary to examine 
 the condensed water from time to time, the more so as leaks in the tubes may 
 also lead to the contamination of the condensed water with juice.* 
 
 Owing to the concentration of the cane juice, various substances which had 
 been dissolved in the thin juice are separated in an insoluble state ; they paitly 
 remain in the juice, rendering it turbid, and partly are deposited as a hard crust 
 on the tubes, mostly on those of the last vessel, and interfere with the conduction 
 of heat, and hence with the evaporation. Attempts have been made to prevent 
 this by placing in the tubes wooden staves about ^ inch less in diameter than the 
 latter ; these possess the double advantage of diminishing the volume of juice 
 passing along a given heating surface, and of affording by their rough surface a 
 better attachment for the incrustation than the smooth brass tubes. This, 
 however, does not prevent the necessity of the vessels being cleansed from time 
 to time, and this is effected by boiling in them caustic soda (or, if this is not to be 
 had, anhydrous carbonate of soda mixed with half its weight of lime, these two 
 constituents together forming caustic soda in the triple-effet). The boiling is done 
 with open valve and with fresh steam in the steam-drum, and hence at the 
 ordinary atmospheric pressure, else the temperature is not sufflcientlj'- elevated ; 
 afterwards the caustic soda is let off, the vessel washed with water and a dilute 
 
 * This exaroiDation can be made by boiling about 50 c.cm, of the condensed water for a few 
 momente with a little hydrochloric acid, neutralizing it afterwards with caustic soda, and heating it 
 again after addition of a little Fehling's solution, in which case a precipitate of red cuprous oxide 
 reveals the presence of sugar. The reaction with an alcoholic o-naphthol solution (10 per cent.), of 
 which 1 c.cm with 3 c.cm. of sulphuric acid and 1 c.cm. of condensed water assumes a blue colouration 
 in case sugar is present, is too sensitive » test, as it detects even trifling traces of sugar which are 
 practically insignificant. 
 
45 
 
 solution of hydrochloric acid boiled in it ; then it is again washed with water, 
 when the tubes can be cleaned by scraping. Note should be taken of the fact 
 that by the action of the acid hydrogen will be given ofE, which forms an explosive 
 mi x ture with the air, and therefore no workmen should enter the vessels with a 
 light before they have been thoroughly washed out with water or the air has 
 been drawn off by the air pump. 
 
 The analysis of scales from the different vessels of a quadruple effet gave 
 these figures.* 
 
 
 l&t vessel. 
 
 2i)d vessel. 
 
 3rd vessel. 
 
 4th vessel. 
 
 
 Per cent. 
 
 Per cent. 
 
 Per cent. 
 
 Per cent. 
 
 Phosphate of lime . . 
 
 . . o7'85 
 
 . 56-98 . 
 
 . 15-02 . 
 
 7-49 
 
 Sulphate of lime 
 
 202 
 
 1-92 . 
 
 0-54 . 
 
 1-65 
 
 Carbonate of lime . . 
 
 . ; 3-25 . 
 
 4-68 . 
 
 19-55 . 
 
 9-93 
 
 Silicate of Hme 
 
 7-86 . 
 
 . 13-31 . 
 
 0-71 . 
 
 7-02 
 
 Oxalate of lime 
 
 — 
 
 — 
 
 . 11-32 . 
 
 . 11-27 
 
 Iron oxide 
 
 2-03 
 
 1-53 
 
 2-31 . 
 
 2-58 
 
 Silica 
 
 7-79 
 
 7-43 
 13-41 . 
 
 39-26 . 
 . 11-04 
 
 54-34 
 
 Combustible matter 
 
 . . 20-37 
 
 5-08 
 
 
 101-17 
 
 . 99-26 
 
 . 99-75 
 
 99-36 
 
 Besides the double, triple, and quadruple-effets already mentioned, 
 horizontal vessels are also used in the system, called " Yaryan," mainly based on 
 the same principle. They have this advantage, that the juice flows rapidly 
 through tubes of small diameter, and is therefore concentrated in a few minutes, 
 but to this end the tubes must be kept clean -nrith great care, and this causes so 
 much trouble that the apparatus seems to find no great favoiur with sugar 
 manufacturers. 
 
 2. CLAItEETCATION OP THE SyBTJP. 
 
 Dui-ing the evaporation many matters held in solution by the clarified juice 
 assume an insoluble condition, owing to the higher concentration. Among these we 
 find — besides silica — gypsumi, phosphate of lime, and caramelaceous substances 
 produced from sucrose or glucose by local overheating, which causes all clarified 
 juices, even the purest, to become turbid again after concentration. It is very 
 important to remove these impurities, for if they become enclosed in the sugar- 
 crystals, as they form during the boiling process, they impart to them a dark 
 tinge, which cannot be got rid of by washing. It is not feasible to remove these 
 matters by filtration, as in factories employing the defecation processes the syrup 
 contains too much pectine to be filtered ; on the contrary, the syi-up from juice 
 clarified by carbonatation passes easily through any kind of juice filter. The best 
 method of clarification is by boiling the syrup in eliminating pans after it leaves 
 the triple-effet, and neutralizing it, if necessary, with soda, or, if it is too 
 alkaline, with sulphurous or phosphoric acid, after which it is run off into 
 settling tanks similar to those already described in Chapter III. 
 
 »Kobu3 Archief, 1900, 691. 
 
46 
 
 If tie precipitate subsides slowly, a little phosphoric acid, together with 
 some lime or soda, may be used in elimination, but great care must be taken not 
 to use too much of these, as in that case the stratum of precipitate might become 
 too thick. 
 
 Sometimes juice, which is neutral after defecation, yields a very acid syrup, 
 but in this case no attempt should be made to remedy the defect by using more 
 lime On tempering, for, however strange it may appear, this is more apt to 
 increase the acidity of the syrup than to diminish it. The only thing that can be 
 done is to neutralize the quantity of juice under operation, and seek immediately 
 for the source of this acidity. In every case where a neutral clarified juice becomes 
 very acid during manufacture, this must be due to some agent, which mostly 
 consists of some fermentative organism or other which attacks sucrose and forms 
 acid from it. As a rule, lime salts favour these fermentations, hence a large use 
 of lime render the conditions of life of these organisms m.ore advantageous, and 
 thus promotes the deterioration. This can therefore be remedied at once by 
 keeping the amount of lime as low as possible, and by great care in cleaning all 
 pipes, tanks, and pumps, and even disinfecting them with a 1^ solution of 
 fluoride of ammonia. It is of course still better to prevent such infection by daily 
 washing out the gutters and settling tanks. 
 
 With juices, too, containing much glucose, a rapid decrease of alkalinity is 
 observed, which however does not change into sourness as is the case with 
 fermentation. 
 
 As soon as the syrup has settled, it is drawn ofi from the precipitate and 
 conveyed to the suction tank of the vacuum pan, while the precipitate is dealt 
 with in various ways. Some manufacturers mix it with the molasses coming 
 from the centrifugals, and boil them together to second sugars. There could not 
 be any objection to this process if the second boilings were always sure of finding 
 a market, for the fine particles of the precipitate would be got rid of in the 
 crystals of the second sugars, but in many cases the second sugars are again 
 melted in the juice, and thus the impurities, previously eliminated with care, are 
 again returned into the juice. Moreover, the introduction of the returning of 
 molasses into the pan has suppressed the second sugars, so that the mixing of the 
 syrup bottoms with first molasses has become impossible. In other factories the 
 scums of the thick juice are run into the scum-tank of the miU-juice, which 
 proceeding has the drawback of increasing the work of the scum filters, and thus 
 diminishing the capacity at that stage. Further, this scum is very slimy, and the 
 fixed particles are excessively fine, so that they will choke up the meshes of the 
 filter-cloths, and finally these scums represent a highly concentrated sugar 
 solution, which results in the scum-cakes being separated from a rather rich juice, 
 and as even the most solid scum-cakes still contain a quantity of free juice, 
 amounting to about oO^, it is not an economical proceeding when we remember 
 that this is concentrated juice, in which a considerable quantity of sugar becomes 
 lost. The best way is to pump the thick juice scums into the juice in the 
 defecation pans ; the syrup becomes mixed with the great volume of mill juice 
 without any visible increase of concentration, and again undergoes all the 
 operations of clarification and setthng, while the fine precipitate is likewise takeix 
 
47 
 
 up by the flocoulent sciuns of the mill juice, subsides with them, and does not 
 give rise to any increase in the quantity of juice to be filtered by the filter presses. 
 Moreover, the higher sugar content of this juice is so trifling, that the loss of 
 sugar in the filter-press cakes is not perceptibly increased. 
 
 3. — Boiling. 
 
 During the boiling process the concentration of the clarified thick-juice is 
 continued to the point where there is not sufficient water for the sugar to remain 
 dissolved, and it is forced to become partially crystallized. This may be done 
 either by evaporating the saccharine solution at a high temperature to such a 
 degree that the clear concentrated syrup only deposits its sugar on cooling down, 
 or by evaporating it at a not too elevated temperature until the sugar commences 
 already to crystallize in the pan, after which the crystals grow slowly as 
 evaporation is continued, and the entii-e mass is ultimately transformed into a 
 stiff magma, consisting of a large quantity of crystals and only a little molasses, 
 in which state it leaves the pan. The rapidity with which sugar crystallizes out 
 from a solution, depends, all other circumstances remaining the same, on the 
 purity of the solution, i.e., on whether much or little foreign substance is present 
 along with the sugar. When the sugar solution is tolerably pure, crystallization 
 takes place as soon as the concentration has become too great for all the sugar to 
 remain in solution ; during the boiling process crystals are already formed in the 
 pan, and so the graining of thick- juice is a somewhat easy operation. When an 
 impure juice, such as molasses, is evaporated, crystallization takes place only 
 very slowly, and no crystals are visible, even when the concentration is much 
 greater than corresponds with the solubility of sucrose. These impure syrups 
 cannot be grained, but are boiled smooth, after which they are allowed to cool 
 down, and after some time sugar crystallizes out, partly because it is less soluble 
 iu cold water than in hot, but chiefly because of its undergoing transition from 
 the supersaturated state into the normal state of solubility. 
 
 Boiling is in the present day always performed in vacuo, for the same reason 
 as already mentioned under the heading "Evaporation," viz., that the high 
 concentration considerably increases the risk of overheating. The syrup or 
 molasses is drawn into the pan, and heated by means of a steam coil, while the 
 vapours are pumped out by an air pump and condensed. 
 
 The oldest vacuum pans were made of copper, but owing to the efforts made to 
 obtain as large a capacity as possible, they are now almost exclusively made of 
 iron, and those of copper, provided with a steam-jacket, are the exception. Yet 
 they had some advantages over those of modern construction ; firstly, the surface 
 of heated metal was greater by some square feet, owing to the copper steam- 
 jacket ; and secondly, the masse-cuite in the pan suffered less from the cooling 
 influence of the atmosphere. 
 
 The boiling to grain is based on the evaporation in the pan of a quantity of 
 syrup to such a concentration that it contains much more sugar than it can hold 
 suspended at rest or at a lower temperature. By suddenly lowering the 
 
48 
 
 temperature a part of this dissolved sugar is thrown down in the shape of fine 
 crystals, and then the skill of the pan-boiler comes into play in making these 
 grow, by repeatedly drawing syrup into the pan and concentrating it without 
 permitting the formation of fresh fine crystals from the syrup afterwards drawn 
 in. Good care should be taken when graining to form at the outset as great a 
 quantity of crystals (numerically) as should ultimately be present in a full- 
 grown state in the masse-cuite. When making coarse grain, we have to form 
 fewer crystals and to boil more slowly than when we want to make fine grain. 
 
 When making sugar of an average size of grain, the procedure is as follows, 
 provided that the purity of the syrup is not too low. By bringing the air-pump 
 into action we commence forming a vacuum in the pan and start the supply of 
 syrup, which is drawn into the pan, and this is continued until one or two coils 
 are covered, into which steam is introduced. With a vacuum of 24 inches, 
 corresponding with a temperatxire of 140° F., the syrup is evaporated, and so 
 much syrup is gradually supplied that the coils, into which steam is admitted, 
 remain constantly covered so as to prevent the emergence from the syrup of any 
 hot surface on which drops of liquid thrown up could get dried, causing 
 decomposition of the sugar contained therein, and changing it into sticky 
 and dark-coloured products. 
 
 The contents of the pan, which at the beginning boiled very briskly, by 
 degrees assume a slower movement corresponding with the increase of concentra- 
 tion, and the evaporation is continued until the pan-boUer can see, judging from 
 the degree of viscosity the spattering syrup marks on the sight-glass, that it is 
 ready for graining. The steam is then lessened and the injection increased, by 
 which operation the temperature of the contents is reduced to about 120° P. The 
 syrup, which was already supersaturated at the higher temperature, can now, at 
 the lower temperature, no longer hold all the sugar, which is deposited in the 
 form of small, bright crystals. After having convinced one's sell, by means of 
 two or three samples taken with the proof- stick, that the quantity of crystals 
 does not increase, the supply of juice is slightly turned on and the syrup is drawn 
 carefully into the pan, either in a continuous stream or with intervals. Next 
 more steam is admitted, and we continue drawing syrup into the pan, which 
 gradually becomes full, and as soon as a coO. of the worm is covered, steam is 
 turned on in it. These data apply to the production of a medium-sized grain; 
 when making coarse grain it is well to grain "low down," i.e., to have only a 
 small quantity of syrup in the pan when graining, using not too concentrated 
 syrup and keeping the contents of the pan in gentle motion by careful manage- 
 ment of the steam and injection apparatus. By this means the particles of sugar 
 are forced to deposit themselves on already existing grain, which is accordingly 
 increased in size, and this growth is further promoted by drawing in large 
 quantities of syrup at lengthened intervals. When making fine grain, the 
 custom is to start graining high up, drawing in repeatedly small quantities of 
 syrup and boiling very rapidly, so as to prevent the crystals from gi-owing too 
 fast ; owing to the violent movement, they are thrown against each other and 
 against the walls of the pan. 
 
49 
 
 By constant sampling with the proof-stick, the boiler should take care to 
 avoid allowing the crystals to be suspended in a liquid too viscous to permit their 
 movement, and yet not too thin, in which case there would be a risk of the already 
 formed grain becoming dissolved. 
 
 When during the boiling process one of these samples proves to contain very 
 small crystals occun-ing between the original 'grains, and imparting a turbid 
 appearance to the mother-liquor, these crystals should be dissolved again. To 
 this end a large quantity of thick juice is drawn into the pan, the injection is 
 diminished, more steam is turned on in order to raise the temperature, which 
 dissolves the fine crystals and also a portion of the large ones, but by causing the 
 temperature to fall again slowly, the latter find opportunity to grow again. 
 
 When the pan is full, the supply of syrup is stopped, and the contents 
 concentrated; the exact point at which this concentration should be arrested, i'.e., 
 the striking point, has to be found by experience, and is deteimined by the 
 firmness a sample taken out of the pan by means of a proof-stick acquires when 
 cooled suddenly in a pail of water. In case a very hard grain is required, the 
 temperature should be kept rather high in the pan (about 150° F. is the most 
 favourable temperature), but in all cases the temperature should be lowered at 
 the end of the boiling process, in order to force the water still present in the 
 naasse-cuite to part with as much sugar as possible. 
 
 As soon as the masse-cuite is ready for striking, the steam is shut off, the 
 air-pump and injector are stopped, and by opening a cock in the pan, air is 
 allowed to pass in, when the discharge valve is opened and the masse-cuite 
 discharged from the pan. When the latter is empty, it is steamed in order to 
 dissolve the particles of sugar still adhering to the walls and coils ; the steamings 
 are kept separate, so that those from several operations may be cured together, or 
 they are again mixed with the cane-juice. Sometimes, when the grain is very 
 minute, only half the contents of the pan are discharged ; it is then closed and 
 fresh syrup is boiled in it, permitting the crystals to grow again — which process 
 bears the name of " cutting." 
 
 When impure thick juice is being worked up, it may be more strongly 
 concentrated on graining than in the case of pure juice, because the crystalliza- 
 tion does not take place so quickly, but as a, rule cane-juice forms grain very 
 easily, and the artifices employed in the beet-sugar industry to promote crystalliza- 
 tion are superfluous here. 
 
 The way in which a masse-cuite is boiled is of the greatest importance as 
 regards the extraction! of the sugar present in it ; when the crystals have sharp 
 edges and ar6 regularly shaped, without any fine crystals (false grain) being at 
 the same time present in the mother-liquor, the molasses easily part from the 
 crystals on curing, and little or no loss ensues. 
 
 On the contrary, if the grain is irregular in shape, or if a considerable 
 quantity of very minute crystals are present, a great deal of the already 
 crystallized sugar passes ofl along with the molasses on cui-ing, and thus becomes 
 lost as available product. The false grain is mixed up with the molasses, forming 
 a viscous compound, which adheres to the larger crystals, and is only to be 
 
 4 
 
50 
 
 removed by copious wasMng with ■water. Besides tlie disadvantage of tHs false 
 grain becoming dissolved during the operation, the water also dissolves a portion 
 of the large crystals, hence diminishing the yield of first sugar. It is therefore 
 evident that where an inexperienced pan-boiler makes from the same quantity of 
 syrup a masse-cuite which gives a low outcome, a skilled man is able to boil it 
 into a very profitable masse-cuite. Close attention should be paid at this 
 stage of manufacture, and every assistant or chief sugar maker should endeavour 
 to learn the art of boiling perfectly, in order to be able to supervise the native 
 workmen properly. 
 
 It is a fact that the quantity of sugar crystallizing from a masse-cuite 
 increases according as the water-content diminishes, though this increase is not 
 proportionate to the increase in concentration. The more a masse-cuite is 
 concentrated, the greater the quantity of sugar that crystallizes, but in practical 
 working certain circumstances prevent the concentration proceeding beyond a 
 certain limit, viz., about 6 to 8 per cent, of water, causing the composition of a 
 first masse-cuite, boiled from average juice, to be : — 
 
 Sucrose . . 81-10 
 
 Glucose 6-93 
 
 Ash 1-12 
 
 Water 8-66' 
 
 Undetermined 2-19 
 
 10000 
 
 A masse-cuite out from impure juice may give the following figures : — 
 
 Sucrose 74-10 
 
 Glucose 11 -07 
 
 Ash 1-54 
 
 Water 9-02 
 
 Undetermined 4-27 
 
 100-00 
 
 But, though it may appear absurd, the quantity of sugar crystallized does 
 not vary very much in the two cases, provided that the amount of water is fairly 
 the same, as sugar is much more soluble iu the amount of water contained in a 
 pure masse-cuite than in that of an impure one, causing the quantity of 
 crystallized sugar to be nearly the same. In the first case, one part of water 
 contains about 2-2 parts of sugar = 19-03 per cent, of the masse-cuite; so that 
 62-07 per cent, of crystallized sugar is present. In the second case, the water 
 contains no more than 1 -6 part of sugar =13-5 per cent, of the masse-cuite, leaving 
 60-6 per cent, of crystallized sugar present, or only about 1-5 per cent, leas than 
 in the former case. 
 
 In any case a masse-cuite always contains, dissolved in the molasses which 
 are removed in curing, some 12 to 18 per cent, of sugar from the original thick- 
 juice, which only comes back in the second boiling, and for this reason it has 
 been attempted to obtain part of this sugar also along with the first runnings. 
 
51 
 
 This may be done by boiling the masse-ouite very close, to such a degree that in 
 ordinary working it would be impossible to get it out of the pan, so that the 
 maximum of sugar crystallizes out. A small quantity (about 6 per cent.) of hot 
 molasses is then drawn in, boiled for a moment with the masse-ouite to obtain 
 thorough admixture, when the latter is discharged, and owing to its greater 
 liquidity is very qtiickly out of the pan. The temperature of the molasses should 
 be higher than that of the masse-cuite for, firstly, cold molasses do not mix well, 
 and, secondly, a part of the sugar dissolved in the hot water of the masse-cuite 
 would be thrown down in the shape of false grain by the rapid cooling. Now it 
 is evident that in this way no considerable advantage can he obtained. Taking 
 5 per cent, of molasses, containing about 25 per cent, of water, the increase of 
 water is no more than 1'25 per cent., and where this is found sufficient to liquify 
 the masse-cuite the total amount of extra water evaporated by the higher 
 concentration has also not been more than 1-25 per cent., and as 1 part of water 
 had held 2 parts of sugar in solution, the entire additional quantity of sugar 
 crystallized by this process has been about 2'5 per cent. 
 
 Another method is boiling very close to a water-content of about 3 per cent., 
 and then diluting with no less than 30 per cent, of hot molasses of about 90° 
 Brix. This mixture, however, cannot be cooled down in the ordinary way, but 
 requires a special cooling in movement as will be mentioned afterwards. This 
 large quantity of molasses is able to liquify even the closest boiled masse-cuite, 
 and will save up to as much as 12 per cent, of sugar, which in the ordinary way 
 of working would have passed over with the second boiling or in the molasses. 
 
 The consideration that good circulation and slow cooling can induce sucrose 
 to deposit on already existing crystals, even from the most impure mother-lyes, 
 has given rise to the adoption of the many methods of returning molasses into the 
 vacuum pan. 
 
 It is a well known fact that by the usual boiling process the desacchariflcation 
 of the molasses can be advanced very much in the case of impure boilings, in 
 which the solubility of sucrose is very slight. 
 
 A masse-cuite having the following analysis — 
 
 Sucrose 74'1 
 
 Of which crystallized 61-62 
 
 ,, dissolved 12-48 
 
 Glucose 11-07 
 
 Ash 1-54 
 
 Moisture 9-02 
 
 Quotient of purity 81-44 
 
 yielded a green molasses, which after being filtered, showed this analysis : — 
 
 Sucrose 32-90 
 
 Glucose 28-59 
 
 Ash .. 3-91 
 
 Moisture 23-37 
 
 Quotient of purity 42-86 
 
52 
 
 Such a low quotient could not be expected wlien centrifugalling a purer 
 magse-cuite ; as witli cane sugar molasses, the sucrose is less soluble the more 
 glucose it contains. Hence it results that with the same amount of water in the 
 masse-cuite, more sucrose is crystallized out from a masse-cuite of a low quotient 
 than from one having a high quotient of purity. 
 
 If, therefore, by a copious addition of molasses to the first masse-cuite, the 
 syrup still present among the sugar crystals in the pan is reduced to the same 
 purity as finally results when boiling masse-cuite from rather impure juice, the 
 same degree of desaccharification may be obtained. 
 
 The purer the syrup is of which the masse-cuite is boiled, the more molasses 
 can be sucked in, and every mill which works with this system should ascertain 
 once for all what proportion of masse-cuite and molasses is the most favourable 
 for every degree of purity. 
 
 Suppose that we know by experience that the best desaccharification of the 
 molasses is attained when centrifugalling a mixed masse-cuite of 65 purity, and 
 let the quotient of the syrup be 85, that of the molasses 37. 
 
 When X is the volume of first masse-cuite on 100 parts of the capacity of the 
 pan we put down this equation — 
 
 85 a; X 37 (100— a;) = 100 X 65 
 .-. X — 58-4: 
 
 It is advisable to calculate this figure for every degree of purity both of the 
 syrup and the molasses, and to enter them into a list. Next the division of the 
 pan should be painted on it so as to enable the pan-boUer to see to what mark he 
 has to fill it vnth masse-cuite from syrup before starting drawing in molasses in 
 every instance. 
 
 The masse-cuite from syrup is highly concentrated to such a degree that no 
 movement is visible through the sight-glasses, next a free quantity of molasses 
 is introduced. As soon as the masse-cuite is sufficiently liquified the molasses 
 supply is diminished and the superfluous water evaporated with exhaust steam, 
 this going on until the pan is full. Finally the molasses supply is stopped, and 
 the contents of the pan are concentrated to 95° Brix. 
 
 Before returning the green molasses into the pan, they are heated by steam 
 to the same, or a little^ higher temperature than that of the already formed 
 masse-cuite in the pan. When heating the molasses, a dark greasy foam arises, 
 which is removed by a large hollow spoon provided with small holes. This 
 heating renders the molasses more dilute and easier to be handled, next it 
 dissolves the fine grains usually prevailing in the green molasses, and this is a 
 great advantage, because if it was introduced thus into the pan it would give rise 
 to a secondary crystallization, which afterwards might cause much trouble in the 
 centrifugals, by its choking up the centrifugal gauze. 
 
 The proportion of the quantity of molasses added to the original masse-cuite 
 does not only depend on the respective purities of both, but also on the use one 
 will make of the green molasses. 
 
 When the aim is to separate the mixed masse-cuite in sugar and exhausted 
 molasses in one operation, more molasses must be added than when it is necessary 
 
53 
 
 to obtain one kind or other of after-products of the same. This point will, 
 however, be elucidated later on. 
 
 When mixing molasses with the close boiled masse-cuite it sometimes occurs 
 that a layer of hard masse-cuite remains at the bottom untouched, and as 
 this is the place where samples are drawn with the proof-stick, this can lead 
 to erroneous conclusions, with regard to the real state of dilution of the 
 contents of the pan. In order to prevent this and in general with a view 
 to promote circulation and to bring along an ascendant current which prevents 
 incrustation of masse-cuite on the steam coils, and thereby overheating and 
 decom.positio n, a thin perforated copper coil is fitted at the bottom in the pan. 
 Dry steam of a low pressure is. introduced in this coil, and owing to the vacuum 
 existing in the pan it penetrates through the masse-cuite stirring it accordingly 
 without interfering very much with the vacuum. Equally to promote a proper 
 mixture it is advisable to suck in the molasses through a bent tube which passes 
 through the masse-cuite and ends at the bottom. The so much lighter molasses 
 entering under the heavy masse-cuite will rise to the surface and thereby ensure 
 a good mixing. 
 
 A third way of promoting circulation is met with in pans where molasses are 
 to be boiled on grain. In these pans the steam is not introduced in coils but in a 
 steam chamber of about the same shape as in a triple-eflet, save that the 
 diameter of the tubes is larger, since the material to be boiled there is so much 
 more viscous. 
 
 The central tube is provided with a stirrer, which agitates the boiling mass 
 and induces a thorough circulation of the same. 
 
 Juices which are very impure, or molasses, cannot be grained just like pure 
 juices, but are boiled smooth. In this process they are concentrated to such a 
 degree that they are saturated at the temperature prevailing in the vacuum pan, 
 and afterwards the sugar that is less soluble in the cold masse-cuite is allowed to 
 crystallize in the crystallization cisterns. For this operation a vacuum is created 
 in the pan, the molasses supply is tui-ned on and molasses are drawn in until the 
 coils are quite covered ; steam is then admitted into them and water evaporated, 
 molasses being drawn in according as the quantity of liquid in the pan diminishes, 
 so as to keep the coils constantly covered. From time to time a sample is taken 
 from the pan and drawn between the thumb and finger, forming a thread, which 
 breaks at a certain length. If the thread breaks too soon, the concentration has 
 not been carried far enough ; if it does not break at all, it has gone too far. The 
 skill and experience of the pan-boiler must decide how much time may be required 
 in each special case, and what appearance the sample ought to have. In the main, 
 we may say that first molasses may be more highly concentrated than second or 
 third, while the temperature at which molasses axe boiled is rather high. When 
 the masse-cuite is sufficiently concentrated, the steam, molasses, and air pumps 
 are shut off, and air is admitted into the pan, which is opened, and the contents 
 run into troughs or wagons placed under the opening. 
 
CHAPTER V. 
 
 Ctjuing of PmsT Stjgae.. 
 
 The operations next following have for their object the separation of the 
 masse-cuite into crystaUized sugar and molasses, and as both these constituents 
 are already present as such, they are only of a mechanical nature. It is evident 
 that the most advantageous way is to efEect this separation in such a manner that 
 the maximum of the crystallized sugar is obtained at once in the first product, 
 because if portions of it become mixed up again with the molasses, they can only 
 be got back after much trouble and expense, and not even then entirely in the 
 less valuable after-products. It has been proved that the curing is most easily 
 effected, and with a minimum of loss, when the sugar crystals are regular and 
 well-developed, and the mother-liquor is limpid, fluid, and not muddied by the 
 presence of fine, so-called "false" grain. 
 
 All the operations which the cane juice has up to now undergone have 
 co-operated to lead to this end. The miUs extracted as much juice as possible 
 from the raw material, clarification removed all matters apt to make the juice 
 turbid, a moderate quantity of lime threw down the pectine and albumen, 
 avoiding the formation of viscous, dark coloured lime-salts, after which filtration 
 rid the juice of all suspended impurities. Concentration in vacuo prevented over- 
 heating and decomposition of sugar, and, finally, good care was taken during the 
 boiling process to form large regular crystals, free from false grain. Notwith- 
 standing all this, careless working between the time when the masse-cuite leaves 
 the pan and the oentrifugalling may nullify all the advantages thus gained. 
 When striking the pan, the water of the hot masse-cuite contains more sugar than 
 it can hold after it has been cooled down. In impui-e masse-cuites this amount is 
 greater than in pure ones, owing to the slow crystallization of sugar from impure 
 liquids, so that all the sugar capable of crystallization has not yet assumed that 
 state in the pan. Under the circumstances prevailing in the crystallizing tanks, 
 in cases where the masse-cuite is very hard and no circulation exists, the sugar 
 afterwards crystallizing out wiU assume the form of false grain. With pure 
 masse-cuites, in which the quantity of this is trifling, the influence of the false 
 grain is not perceptible, but from impure masse-cuites, especially when they 
 have been boiled at a high temperature, a great deal of sugar will crystallize 
 out afterwards, and even if the boiling is conducted as efficiently as possible, will 
 cause the cooled masse-cuite to contain so much false grain that trouble and 
 loss will arise on curing them. 
 
 This is especially the case with such masse-cuites as are boiled very close 
 and afterwards diluted with a large quantity of hot molasses ; if these should be 
 cooled down without certain precautions, amass would result that practically 
 could not be divided into crystals and molasses. Pure masse-cuites can safely be 
 
56 
 
 cooled down in the crystallizers, and then yield the maximum outcome, but very 
 impure ones should either be centrifugalled hot from the pan (in which case 
 the sugar crystallizing afterwards cannot interfere with the centrifugaUing), or 
 they should be cooled in movement, which operation is indispensable with masse- 
 cuites mixed with molasses. 
 
 We have already seen that in the pan the sugar crystals are in constant 
 movement, and come successively in contact with all parts of the liquid from 
 which the sugar is crystallizing out ; as a consequence, the crystals grow in size 
 by the sugar depositing itself on them in place of forming new crystals. If this 
 movement is also continued during the cooling down of the masse-cuite, and that 
 cooling takes place slowly and regularly, the sugar afterwards crystallizing out 
 likewise deposits itself on already existing crystals, and does not form false grain; 
 and at the conclusion of the operation even the most impure masse-cuite consists 
 of a mixture of regular, well-fonned grains and a limpid molasses not adherent 
 to the crystals. This operation is called crystallization in motion, and in combina- 
 tion with the dilution of close-boiled masse-cuites with a large volume of hot 
 concentrated molasses, it enables us to get the maximum amount of sugar from 
 a masse-cuite, because, firstly, much water having been evaporated, therefore the 
 maximum of sugar crystallizes ; and, secondly, the systematic cooling causes the 
 crystals to assume such a form that they can be obtained on centrifugaUing 
 without appreciable loss. 
 
 The apparatus for crystallization in movement may be divided into two 
 groups, viz., the open and the closed. Both of these consist of cylindrical 
 vessels, sometimes provided with a "jacket,"' into which hot or cold water can be 
 introduced, but having in all cases a shaft with dashers arranged in spiral form, 
 which by revolving keeps the contents in regular and gentle motion. 
 
 The open vessels are quite uncovered, and the masse-cuite runs into them 
 through an open trough, while on the contrary the closed vessels have an air-tight 
 connection with the discharge -pipe of the pan and with the mixer placed above 
 the centrifugal; besides this, they can be worked imder vacuum, and an air- 
 compressor is fitted to them to bring in compressed air. When the highly 
 concentrated masse-cuite is diluted with from 30 to 50 per cent, of its volume of 
 hot molasses of about 90° Brix., steam is turned ofi from the pan, the air-cock is 
 opened and also the discharge valve, and air is then pumped out from the vessel ; 
 consequently the diluted masse-cuite is drawn into it with great rapidity, when 
 the pan is again ready for immediate use. The opening is now closed and the 
 masse-cuite is slowly cooled in constant movement, after which compressed air is 
 admitted to the vessel and the discharge-vent opened, causing the cold masse- 
 cuite to pass out into the mixer of the centrifugal. In the open systems, the 
 similarly prepared masse-cuite runs through an open gutter into the vessel, is 
 stirred, and afterwards let ofi by a kind of sluice into a suction-tank, from which 
 it is conveyed to the centrifugal by means of a chain-pump or an elevator. Before 
 the masse-cuite is run in, the apparatus should be heated in order to prevent the 
 hot masse-cuite from depositing minute grain on coming in contact with the cold 
 plates. The shaft should already be in motion on the entrance of the masse-cuite. 
 
56 
 
 causing the latter to gradually assume a revolving movement, so that there is 
 no need for starting the movement when the vessel is already full, which might 
 involve risk of breakage. During the stirring and cooling, the masse-cuite 
 becomes harder and harder, and frequently more hot molasses have to be added in 
 order to prevent the breaking of the dashers. After some time, water is introduced 
 into the jacket in such apparatus as are furnished with one. In those which are 
 not, the mass has to cool down by contact with the air — too rapid cooling and too 
 short time of stirring should equally be avoided. When cooling too quickly, the 
 sugar crystallizing out has no opportunity of attaching itself to the old grain, and 
 will therefore form false grain between the large crystals; while if we do not 
 wait till the mixture is sufficiently cold, too much sugar that is still capable of 
 crystallizing is carried off in the molasses in a state of solution, and so the full 
 effect of the operation is not obtained. The most profitable time for stirring, in 
 the case of vessels holding 2,000 gallons, is from 15 to 16 hours. 
 
 The differences between using open and closed vessels are as follows : — 
 
 The systems with closed vessels have the advantage of allowing the 
 manufacturer to place them (within certain limits) where he likes; by means 
 of the vacuum and the compressed air, the maese-cuite can be conveyed 
 mechanically for some distance and raised a certain height without risk of bruising 
 the crystals. They have, however, the disadvantage of there being a great difficulty 
 in getting a good sample from the interior of the vessel, if it be desired to stir the 
 masse-cuite in vacuo. If not, the manhole is simply opened during stirring, and 
 it is only closed when the masse-cuite has to be discharged from the vessel. The 
 closed vessels are therefore under the same conditions as the open ones, and the 
 operation can be surveyed from beginning to end ; the mixing of the masse-cuite 
 with the molasses, the heating and cooling, formation or re-dissolving of false 
 grain, &c. The open vessels have the disadvantage that their position is restricted 
 to the close vicinity of the vacuum pans and centrifugals. If the masse-cuite 
 cannot run immediately into the vessels and from those into the suction-tank of 
 the centrifugals, it is necessary to have expensive machinery to convey it from one 
 place to another, which is not only costly as regards the price, but also because a 
 masse-cuite pump or an elevator crushes a great deal of grain, which impedes the 
 curing, and the crushed grain finally becomes lost as first product. 
 
 The advantages of crystallization in movement are most obvious ia the case 
 of impure masse-cuites, in its bringing over the after-crystalHzing sugar also, in a 
 form most available for centrifugalling. For the same reason a large percentage 
 of impure molasses can safely be added to a pure masse-cuite, because even if a 
 portion of the sugar crystals are thereby dissolved, it crystallizes again in a 
 good form by being cooled down in movement. The following table supplies a 
 good illustration of the fact that crystallization in movement does not aflect the 
 quantity of sugar crystallized out, but only the form in which it crystallizes. Here 
 the analyses of four impure masse-cuites of almost similar composition are given, 
 with the analyses of the molasses existing amongst the crystals, the amounts of 
 crystallized sugar, and of sugar obtained on centrifugalling. Three of them were 
 cooled down at rest and one in movement. 
 
57 
 
 
 Massb-cuitb. 
 
 Molasses draikkd out. 
 
 i! 
 
 '1 ^ 
 
 Ill 
 
 
 COOLHI). 
 
 i 
 
 m 
 
 S 
 
 5 
 
 ■5 
 
 1 
 
 «1 
 
 la 
 
 1 
 
 5 
 
 
 
 
 O 3 O 
 
 At rest 
 
 in 
 
 78-9 
 790 
 77-0 
 
 11-07 
 8-99 
 8-47 
 9-62 
 
 1-64 
 116 
 1-15 
 2-61 
 
 9-03 
 7-76 
 7-83 
 7-49 
 
 81-44 
 85-33 
 85-72 
 8S-46 
 
 33-9 
 33-7 
 32-9 
 35-3 
 
 38-69 
 28-13 
 27-62 
 36-54 
 
 3-91 
 3-65 
 3-72 
 6-70 
 
 33-a7 
 34-50 
 36 12 
 32-94 
 
 42-86 
 44-63 
 44-67 
 46-40 
 
 61-63 
 68-22 
 69-09 
 64- 
 
 51-51 
 58-81 
 65-28 
 64- 
 
 
 »» tj 
 In movement 
 
 13-79 
 19-88 
 
 From these figures it results that the quantity of sugar crystallized did not 
 differ much in £ill four cases, neither did the chemical analysis of the masse-cuite 
 and of the molasses drained off sho-w any considerable difference, but there are 
 marked differences in the quantity of sugar obtained on curing. While all the 
 sugar crystallized out in the masse-cuite cooled in movement could be obtained 
 on curing, in the other cases, -where the after crystallization had taken place at 
 rest, so much false grain had been formed that no less than 13 to 20 per cent, of 
 the crystallized sugar got dissolved again. This table therefore sho-ws clearly the 
 great influence of the shape of the crystals on the yield obtained, and ho-w 
 important it is to pay close attention to the boUing of first sugar, where by -want 
 of care more loss can be suffered than at any other stage of the manufacture. 
 Apart from the important advantage of improving the shape of the crystals, 
 crystallization in movement has the further advantage of being a cleanly 
 operation and free from mechanical losses. 
 
 The question as to which is best, curing the mixed masse-cuites warm or 
 cold, has been a matter of much discussion ; and if the latter, whether cooling in 
 movement is necessary or not. 
 
 Generally speaking, one can say that when green molasses are desired, which 
 still yield after-products, no cooling is necessary, but in the contrary case cooling 
 is indispensable if the aim. is to separate the masse-cuite in sugar and exhausted 
 molasses. In the first case the vessels serve merely as wash-tanks for the 
 centrifugals, and could just as well be replaced by a gutter provided -with an 
 Archimedean screw which carries the hot masse-cuite to the masse-cuite pump. 
 
 In the vessels for crystallization in movement but little sucrose crystallizes 
 out from the molasses present in the masse-cuite during the first hours, and 
 ■the quotient of purity of thja molasses does not then decrease much as is 
 shewn by the table below. During the cooling process a little masse-cuite 
 was taken from the vessel from time to time, then the molasses was allowed to 
 dram off through a funnel of centrifugal gauze, after "which this molasses -was 
 analyzed in the usual way. 
 
 Brii. Pol. Quotient. 
 
 Syrup 45-48 .... 40-0 87-3 
 
 Molasses — — .... 41-0 
 
 Mixed masse-cuite 94-58 .... 6T-2 71'5 
 
58 
 
 Sample taken. 
 
 Temperature. 
 
 Brix. 
 
 Pol. 
 
 Quotient 
 
 During strike 
 
 .. .. 64-5 . 
 
 . 91-43 . 
 
 . 39-4 . 
 
 . 43-09 
 
 After 1 hour . . 
 
 .... 64-5 . 
 
 . 91-43 . 
 
 . 39-4 . 
 
 . 43-09 
 
 ,, 3 hours 
 
 .. .. 63 
 
 . 90-91 . 
 
 . 39-0 . 
 
 . 42-9 
 
 „ 4 ,. 
 
 .... 63 
 
 . 91-06 . 
 
 . 38-8 . 
 
 . 42-69 
 
 „ ,, .. ,. 
 
 .. .. 62 
 
 . 91-06 . 
 
 . 38-5 . 
 
 . 42-28 
 
 )> 7 ,, .. . 
 
 .... 61-5 . 
 
 . 90-96 . 
 
 . 37-9 . 
 
 . 41-66 
 
 „ 8 „ .. .. 
 
 .. .. 61 
 
 . 91-20 . 
 
 . 37-8 . 
 
 . 41-44 
 
 „ 9 „ .. . 
 
 .... 60 
 
 . 91-20 . 
 
 . 37-8 . 
 
 . 41-44 
 
 „ 10 „ .. .. 
 
 .. .. 59 
 
 . 91-16 . 
 
 . 37-6 
 
 . 41-24 
 
 „ 11 „ .. . 
 
 .... 58 
 
 90-96 . 
 
 . 37-6 . 
 
 . 41-34 
 
 „ 12 „ .. .. 
 
 .. .. 58 
 
 . 91-30 . 
 
 . 37-5 . 
 
 . 41-10 
 
 „ 13 „ .. . 
 
 .... 57 
 
 . 91-24 . 
 
 . 37-5 . 
 
 . 41-10 
 
 „ 14 „ .. .. 
 
 .. .. 56 
 
 . 90-66 . 
 
 . 37-4 . 
 
 . 41-25 
 
 „ 15 „ ... 
 
 .... 56 
 
 . 91-30 . 
 
 . 37-3 . 
 
 . 40-85 
 
 When stirring for a longer time without cooling by water a larger 
 desaccharification was obtained as is shown here. The analysis showed Brix. 
 82-36, Pol. 48-6, Quot. 59. The masse-cuite was concentrated to 91-32 Brix., 
 struck, and stirred during 36 hours. 
 
 Sample taken. 
 
 During strike 69 
 
 After 2 hours 
 
 4 
 
 !> 6 ,, 
 
 iperature 
 
 Brix. 
 
 Pol. 
 
 Quotient 
 
 69 
 
 . 87-76 . 
 
 . 43-0 . 
 
 49-00 
 
 67-5 
 
 . 87-60 . 
 
 . 41-6 . 
 
 47-49 
 
 66 
 
 . 87-30 . 
 
 . 410 . 
 
 46-97 
 
 64 
 
 . 87-96 . 
 
 . 40-2 . 
 
 45-00 
 
 62-5 
 
 87-62 . 
 
 . 39-9 . 
 
 45-50 
 
 60 
 
 87-62 . 
 
 . 38-8 . 
 
 44-28 
 
 57 
 
 . 87-62 . 
 
 . 38-2 . 
 
 43-60 
 
 54-5 . 
 
 . 86-90 . 
 
 . 37-2 . 
 
 42-80 
 
 52 
 
 . 87-76 . 
 
 . 37-0 
 
 42-17 
 
 51-5 . 
 
 . 87-76 . 
 
 . 36-6 . 
 
 41-70 
 
 — 
 
 . 83-56 . 
 
 . 36-4 . 
 
 43-58 
 
 „ 12 „ 
 
 „ 16 „ 
 
 „ 20 „ 
 
 „ 24 „ 
 
 „ 36 „ 
 
 Oentrifugalled molasses 
 
 The difference in purity between the molasses prevailing in the masse-cuite 
 and in those drained off in curing, is due to the fact that a little water was used 
 for covering the sugar, which dissolved a little of it and raised the purity of the 
 molasses. 
 
 It is obvious that the process of making first sugar and molasses in one 
 uperation requires a very large cooling capacity, but a very ingenious device has 
 been invented to restrict this considerably. This consists herein that usually so 
 much molasses is added to the masse-cuite that on cooling down to 60 or 61° C. 
 the purity of the molasses is as low as 40-45. Once or twice a day, dependent on 
 the quantity of molasses on hand, molasses is added to a carefully prepared 
 masse-cuite, which occupies a certain volume, ascertained by experience, of the 
 vacuum pan. The pan is gradually filled with the molasses, concentrated to 95° 
 and struck in the mixers where it is cooled down carefully and constantly kept in 
 motion, until the temperature has fallen to 40° C. and the sugar allowed to 
 
59 
 
 crystallize out, lea-ving an exhausted molasses, which, is drained off in the 
 centrifugals and removed from the further course of manufacture. 
 
 The question whether it is necessary or useful to return molasses into the 
 first masse- cuite is entirely dominated by the class of sugar which is to be made. 
 Wheu making white sugar in which the faintest yellow tinge is a disadvantage, 
 only pure masse-cuite should be boUed without any addition of molasses. When 
 refining-crystals are made a returning of molasses in order to be able to evaporate 
 the last particles of water from the original masse-cuite will be quite correct. If 
 one still wishes to make an after-product from the molasses no cooling is 
 necessary; cooling on the contrary is indispensable when total separation of 
 commercial sugar and exhausted molasses is aimed at. 
 
 The separation of crystals and molasses (properly speaking) is effected in 
 centrifugals ; these are flat, cylindrical drums, with perforated walls, provided 
 with a bottom but open at the top, which are made to revolve with great velocity. 
 The masse-cuite is poured into these and is flung by the centrifugal force against 
 the perforated walls, which keep back the crystals, but allow the molasses to pass 
 through. In case the masse-cuite contains false grain, this either passes through 
 the holes along with the molasses and becomes lost for the time, or, what is still 
 worse, gets mixed up with the molasses, forming a sticky mass which chokes the 
 holes in the gauze of the centrifugal and thus prevents the further draining oS of 
 the molasses. Not until this mass is again dissolved by steam or water is the way 
 cleared, but by such appKcation of solvents a quantity of the large crystals are 
 likewise dissolved and pass over into the molasses. 
 
 Before putting the masse-cuite into the centrifugals, it should be prepared 
 for the operation, as the hard mass is not fit for centrifugaUing without 
 preliminary treatment. Masse-cuite cooled in any apparatus for crystallization 
 in movement is ready for curing, but a masse-cuite cooled in the ordinary way 
 must first be broken up into loose crystals in a pug mill , where it is mixed with 
 molasses and reduced to a homogeneous mass — thus obviating the risk of charging 
 the centrifugals irregularly. 
 
 When making so-called " non-chemical" sugar, it is sufficient to centrifugal 
 until no more molasses flow ofE, and then a thin layer of molasses remains 
 adhering to the crystals and imparting to them a brown colouir. If, however, 
 high-class sugar has to be made, this layer has also to be removed, which is done 
 by pouring water on the sugar in the centrifugal ; the water dilutes the molasses 
 and causes them to be flung through the perforated walls— which operation is 
 called "covering,'' or washing. This ought to be performed very cautiously in 
 order to prevent too much sugar being dissolved at the same time. To this end 
 various apparatus have been devised, intended to throw the water in a fine spray 
 over the sugar in the drum, and so to moisten a large surface with a smaU. 
 quantity of water, or a nearly saturated solution made of less valuable sugar is 
 used for covering, which, while it removes the molasses, cannot dissolve any 
 crystallized sugar. Finally, steam is used for covering, or a jet of steam which 
 carries air along with it ; the steam becomes condensed on the crystals, forming 
 water, which dissolves the thin layer of molasses and is drained ofl along 
 with this. 
 
60 
 
 It sometimes happens that the m.ola8ses present in the masse- ctiite are so 
 sticky that they do not permeate the crystalline crust, but remain on the inside 
 of it in the form of a black ring, which cannot be got rid of by washing ; the only 
 thing that can then he done is to stop the centrifugal after it has run for a certain 
 time, and mix the sugar with the layer of tough molasses by stirring, and then 
 centrifugal again. 
 
 When the adhering molasses have a very low quotient so that they may be 
 removed as exhausted, and though one would make a high-class sugar, one is 
 compelled to use a great deal of water for covering. This dilutes some sugar and 
 would increase the purity of the molasses if it were allowed to flow into the same 
 receptacle as these. Many expedients have been invented to prevent this by 
 separating the green molasses from the covering water, which permits the 
 possibility of a free use of the latter without fear of losing too much sugar. 
 
 The simplest way of performing this is to put two gutters before the 
 centrifugals, one for the poor and one for the rich runnings. A lid moveable on 
 a pin receives the molasses from the centrifugal and, by simply inclining it to one 
 side or the other, discharges them into that gutter where it belongs. This is, 
 however, not quite sufficient as the viscid poor molasses have not yet entirely left 
 the outer drum when covering has already started so that a partial mixing of 
 the two in the outer drum cannot be avoided. Another method is an arrangement 
 in the outer case of the centrifugal, which separates the two runnings ; this 
 necessitates the centrifugals being able to rotate in two directions which may be 
 achieve by an improvement in their driving-gear. 
 
 A third method is the curing in two sets of centrifugals. In the first set the 
 poor molasses are drained ofl, next the raw sugar is centrifugalled in the second 
 set after having passed a pug mill, where it becomes mixed with the rich 
 runnings. The runnings from this second set are partially used for mixing the raw 
 sugar, while the remainder is earned back into the juice. It is not advisable to 
 bring it hack into the syrup because its density is much higher and it might 
 cause trouble to the pan-boiler when he does not work with syrup of a uniform 
 density. 
 
 After curing, sugar in most cases requires to be dried. Formerly sugar was 
 dried in the sun on a plastered floor, but owing to this operation being dependent 
 on the weather and rather expensive, it has been generally abandoned, and the 
 sugar is now dried in large revolving iron cyKnders, in which are fitted steam 
 coils, or through which a current of hot air is drawn by a suction pump that carries 
 ofl the vapours. 
 
 Finally, the dry Java sugar is packed in bamboo baskets lined with pabn- 
 leaf mats, containing from 6 to 7 cwt., and is then ready for sale. 
 
CHAPTER VI. 
 
 Afteb-produots. 
 
 The molasses draiuing off from the centrifugals sometimes stiU contain a 
 considerable quantity of sugar, a certain portion of which can be obtained by 
 repeated evaporation, cooling and centritugalling. The purer the masse-cuites, 
 the greater mil be the quantity of this sugar, as a masse-cuite with much 
 glucose contains less dissolved sugar than one having the same water content 
 with but little glucose. Moreover, a molasses containing much false grain, or 
 one centrifugalled off from high-class sugar which required much water for 
 " covering," is much richer in sugar than molasses centrifugalled from non- 
 chemical sugar or originating from masse-cuites that are treated by one or 
 another method of crystallization in movement. It is therefore not possible to 
 give exact figures for the composition of such first molasses, as all the 
 circumstances mentioned may have exercised an influence on it. 
 
 When considering molasses only as the mother-Uquor from which has been 
 removed all sugar that can crystallize under the given conditions, and which, 
 therefore, only contains such quantity of sugar as it can hold dissolved in its 
 contained water, or, in short, when considering molasses having the same 
 constitution as it had when present among the crystals in a completely cooled 
 masse-cuite, we notice a certain regularity in the quantity of sugar held in 
 solution. 
 
 At the temperature of 85'^F., usually prevailing in the tropics, one part of 
 water is able to dissolve 2-158 parts of sugar, and if this solubility were not 
 changed by other constituents of the molasses, a molasses containing 25 per cent, 
 of water would show a polarization of 53-92 per cent. Now the constituents, 
 other than sucrose, which occur in cane-sugar molasses generally possess the 
 property of diminishing the solubility of sugar, contrary to those found in beet- 
 sugar molasses, in which the solubility of sucrose is usually greater than 
 corresponds with the water content. This property is not to be ascribed to glucose 
 alone, for it has been proved by experiment that even large quantities of glucose 
 do not interfere with the solubUity of sucrose in water. All the remaining 
 constituents, viz., water, salts of organic and inorganic acids, pectine, gums, 
 albumen, caramel, &c., are equally found in both kinds of molasses, and 
 cannot diminish the solubility here while in beet-sugar molasses they are even 
 considered to increase it. After minute researches, it is estabhshed that the 
 diminished solubility of sugar is occasioned by the simultaneous presence of 
 glucose and salts, especially those of organic acids, and this in such a manner 
 that the lowest solubility corresponds with the highest quotient between glucose 
 and salts. There is however a limit to this, for if the quantity of salts is so trifling 
 that it is almost nil, their action is too insignificant to be able to exercise any 
 influence. In case the quantity of salts is so great that it is preponderant as 
 
62 
 
 regards the glucose, these constituents increase the solubility of the sugar, just as 
 is the case with beet-sugar molasses, which likewise contain a large quantity of 
 salts, but little or no glucose. 
 
 A series of cane molasses of diflerent origin, all representing fully crystallized 
 mother-liquors, will show this regularity tolerably clearly. 
 
 Absolutely strict regularity, however, does not exist, and it could not be 
 expected, where, as in the table, the glucose has been divided by the sum of all 
 the ash constituents, as each of these constituents is, of course, sure to have had 
 its particular share in the decrease of the solubility. Notwithstanding this, a 
 steady decline in the figure representing the solubility, accompanying a rise of 
 the quotient between glucose and ash, is perceptible. 
 
 The consequence is that where in cane juices the amount of inorganic 
 constituents does not vary very much, while that of the glucose does, the 
 crystallization of sugar is greatest in those masse-cuites containing the largest 
 amount of glucose, causing the crystallization of sugar to be comparatively large 
 in impure masse-cuites. This point at the same time afiords an explanation of 
 the fact that first masse-cuites, containing very varying amounts of sugar with a 
 like amount of water, yet contain pretty nearly the same percentage of crystaUized 
 sugar. In those containing most sugar, hence the purest, with a like amount of 
 water, the solubility is greater, and hence more sugar has remained in solution. 
 This consideration must not, however, lead to the conclusion that we had better 
 leave the juices as impure as possible, in order to ensure a complete exhaustion of 
 the molasses, for it should not be forgotten that the great quantity of non- 
 saccharine matters also increases the total quantity of molasses, so that though 
 with impure juices relatively little sugar is dissolved in a given quantity of 
 molasses, the absolute quantity of sugar lost in the much larger amount of 
 molasses (due to the impurities) is so much the greater. 
 
 In considering the table, it must be borne in mind that in practical working 
 the molasses contain more sucrose, as it is impossible in daily working to free 
 them so completely from minute grain as has been done here in the laboratory, 
 especially in the case of first molasses coming from masse-cuites, the sugar of 
 which required much washing, which are generally enriched by the water used in 
 that operation. 
 
 As the first molasses are generally diluted in the factory with water or 
 the condensed steam used for washing, they are in a very favourable condition 
 for fermentation, and should therefore be concentrated as quickly as possible. 
 Now molasses contain, as is self-evident, all the impurities from the masse-cuite 
 in a much more concentrated state than they were in the juice, sometimes even to 
 such a degree that a fresh clarification may become necessary. Strictly speaking, 
 we should never omit to clarify all molasses again before boiling them. 
 
 To this end they are run into an eliminating pan, and heated by means of a 
 steam jet. A greasy tough froth now appears on the surface, which is skimmed 
 off, and contains all the floating and suspended impurities of the molasses. At 
 the same time the hot steam, in combination with the resulting dilution, dissolves 
 the fine crystals which had passed through the interstices of the wire gauze in the 
 centrifugal, and were suspended in the molasses. 
 
63 
 
 No. 
 
 Sucrose. 
 
 Glucose. 
 
 Ash. 
 
 Water. 
 
 Glucose : 
 Ash. 
 
 Sucrose on 
 
 100 parts of 
 
 Water. 
 
 1 
 
 47-90 
 
 17-44 
 
 7-0 
 
 16-45 
 
 2-49 
 
 291-1 
 
 2 
 
 47-80 
 
 14-53 
 
 6-66 
 
 17-12 
 
 2-18 
 
 279-2 
 
 3 
 
 43-70 
 59-20 
 
 15-80 
 7-29 
 
 6-50 
 607 
 
 17-10 
 25-12 
 
 2-43 
 2-31 
 
 255-6 
 
 4 
 
 235-6 
 
 5 
 
 58-70 
 
 9-97 
 
 3-82 
 
 25-71 
 
 2-61 
 
 227-8 
 
 6 
 
 50-20 
 
 15-14 
 
 4-35 
 
 25-31 
 
 3-48 
 
 198-3 
 
 7 
 
 35-30 
 49-00 
 
 27-60 
 16-52 
 
 8-08 
 2-52 
 
 19-10 
 
 27-77 
 
 3-42 
 6-56 
 
 184-3 
 
 8 
 
 180-0 
 
 9 
 
 36-90 
 
 26-30 
 
 4-97 
 
 23-2 
 
 5 •29 
 
 159-0 
 
 10 
 
 33-80 
 
 28-20 
 
 6^-88 
 
 22-98 
 
 4-10 
 
 151-5 
 
 11 .. 
 
 43-10 
 
 20-87 
 
 3-39 
 
 28-45 
 
 6-16 
 
 150-8 
 
 12 
 
 34-10 
 
 23- 
 
 7-8 
 
 22-90 
 
 2-95 
 
 149-0 
 
 13 
 
 42-90 
 34-05 
 
 19-93 
 28-12 
 
 3- 
 3-65 
 
 28-93 
 24-50 
 
 6-64 
 7-70 
 
 148-6 
 
 14 
 
 145-7 
 
 15 
 
 34-05 
 23-94 
 
 27-78 
 40- 
 
 4-16 
 5-30 
 
 25-38 
 18-0 
 
 6-67 
 4-31 
 
 134-2 
 
 16 
 
 133-0 
 
 17 
 
 30-90 
 32-19 
 
 27-74 
 30-30 
 
 6-37 
 3-77 
 
 24-14 
 26-22 
 
 4-31 
 8-03 
 
 128-0 
 
 18 
 
 126-6 
 
 19 
 
 32-90 
 29-60 
 
 27-5? 
 32-40 
 
 3-72 
 5-79 
 
 26-12 
 23-80 
 
 7-40 
 5-6 
 
 126-0 
 
 20 
 
 152-2 
 
 21 
 
 30-34 
 
 28-57 
 
 4-02 
 
 25-01 
 
 7-11 
 
 121-3 
 
 22 
 
 30-69 
 
 31-73 
 
 3-65 
 
 25-77 
 
 4-17 
 
 119-1 
 
 23 
 
 28-50 
 28-12 
 
 32-81 
 31 -82 
 
 4-52 
 4-64 
 
 24-06 
 24-44 
 
 7-26 
 6-86 
 
 118-4 
 
 24 
 
 115-1 
 
 25 
 
 32-40 
 
 23- 
 
 5-20 
 
 28-6 
 
 4-42 
 
 113-3 
 
 26 
 
 27-01 
 
 37-46 
 
 3-09 
 
 25-58 
 
 12-12 
 
 105-6 
 
 27 
 
 27-20 
 22-42 
 
 30- 
 34-57 
 
 5- 
 3-30 
 
 28- 
 26-07 
 
 6- 
 10-46 
 
 97-2 
 
 28 
 
 86-0 
 
 It is very important that the molasses should come into the pan clear, and 
 free from suspended particles of sugar, for if they enter the pan in a turbid state, 
 the crystals settle on the coils of the steam pipe and are the cause of many 
 products of decomposition, due to over-heating. Moreover, during the elimination 
 a good opportunity is -afforded for breaking up any excess of lime-salts by 
 sulphurous or phosphoric acid, or for neutralizing too acid molasses with 
 lime, or better still, with soda. The best way is to heat the molasses as they are, 
 without any addition, with their own acid reaction, skim o£E the floating impurities, 
 and if necessary neutralize them afterwards. 
 
 Pure first molasses, such as are obtained when making white sugar, can be 
 boiled on grain and cooled in motion. The chief requirement is that their purity 
 be sufficiently high as to allow their being boiled on grain, which can only be 
 done with very superior runnings. 
 
64 
 
 These first molasses, witli a quotient of from 65 to 61, are grained in a 
 special vacuum pan, concentrated, and struck in an apparatus for crystallization 
 in movement, which is caused to revolve a few times a day during a few hours. 
 After some two or three days the cooled second-boilings masse-cuite is 
 centrifugalled. 
 
 While under the old and still much used systems, the molasses require 
 repeated boiling, cooling, and curing before they could be fully exhausted, this 
 result is now obtainable in one operation, as is shown by the following tables, in 
 which again the figures refer to the molasses occurring among the sugar crystals 
 in the masse-cuites. 
 
 Analysis of the masse-cuite: Brix. 92-6, Pol. 59-2, Glue. 12-25, Quot. 63-93. 
 
 Sample taken. Temperature. 
 
 Brix. 
 
 Pol. 
 
 On striking 
 
 72 .. 
 
 91-3 . 
 
 . 45-0 
 
 After 24 hours 
 
 60 
 
 89-7 . 
 
 . 36-8 
 
 „ 48 „ .. 
 
 51 
 
 88-9 . 
 
 . 34-0 
 
 ,, 72 „ 
 
 44 .. 
 
 88-6 
 
 32-8 
 
 „ 96 „ 
 
 39-5 .. 
 
 88-3 . 
 
 . 31-2 
 
 OentrifugaUed molasses . 
 
 — .. 
 
 87-4 . 
 
 . 34-0 
 
 Glue. 
 16-12 
 18-31 
 19-22 
 20-83 
 21-27 
 19-84 
 
 Quotient. 
 
 49-28 
 41-02 
 38-24 
 37-02 
 35-33 
 38-90 
 
 The less pure molasses are drawn into the pan and boiled smooth, the first 
 molasses rather close, the second (if necessary) more open. 
 
 Contrary to what is the case with the boiling of grain, where the object is to 
 form as much crystal as possible in the pan, and hence care is taken to boil at a 
 low temperature at the end, molasses are boiled at a high temperature in order to 
 allow the masse-cuite to become highly concentrated before the sugar finds an 
 opportunity for crystallizing. While the final temperature of a first sugar 
 masse-cuite very seldom exceeds 135° P., a first molasses masse-cuite is generally 
 discharged at a temperature of 155° F. 
 
 These high temperatures have the disadvantage, owing to the steadily 
 increasing percentage of glucose, of readily forming decomposing bodies, 
 especially from the Isevulose present, so that it is not desirable to proceed too far 
 in this direction. 
 
 Fixed rules for the boiling of molasses cannot be laid down, chiefly because 
 the composition of first, second, or third molasses varies irregularly, and under 
 certain circumstances a third laolasses may be purer and richer than a first one. 
 
 This may be seen from the preceding table, where Nos. 2, 4, 5, 6, 8, 11, 13, 
 and 19 are centrifugalled from first products; Nos. 1, 15, 18, and 21 from first 
 molasses masse-cuites; Nos. 17, 22, 26, and 28 from second; Nos. 10 and 24 
 from third molasses; while Nos. 3, 7, 9, 12, 16, 20, 28, 25, and 27 represent 
 completely worked out final m.olas8e8. We see that the molasses Nos. 14 and 19, 
 originating from first product, were yet poorer than many that had already been 
 boiled several times, and even than some final molasses, so that it is evident that 
 the way in which the different molasses are to be boiled should be ascertained 
 by experiment in each individual factory. 
 
65 
 
 The boiled molasses are discharged into crystallization tanks, where they are 
 allowed to cool down, and where the sugar that can now no longer be retained in 
 solution finds opportunity to crystallize. The rapidity of this crystallization and 
 the size of the crystals depend, in addition to the rapidity with which the cooling 
 goes on. On the nature of the liquid in which they are formed. Pure liquid 
 molasses deposit much more quickly a larger grain than impure and viscous 
 ones, where the cooling time is the same ; therefore first molasses masse-cuites 
 are generally allowed to cool down for a week, second ones a fortnight, and so on, 
 before being centrifugalled. From what has already been said it results, however, 
 that these limits need not be scrupulously adhered to, and an impure first- 
 molasses masse-cuite may be allowed more than a week to crystallize, if this can 
 be done without interfering with the regular operations, though the dimensions of 
 the crystallizers have also a good deal to do with the matter. The cooling and 
 crystallization are much more quickly effected in small iron cisterns, standing 
 quite free, than in large brick ones, built up from the ground. 
 
 As a rule the cisterns should be of sufficient size for the contents of one pan to 
 fill them completely and not so large as to be only filled after three or four 
 consecutive operations, for in this case the crystallization is disturbed every time 
 a fresh supply is run in, and hence the grain formed is irregular. 
 
 Although it is not possible to give constant figures for the constitution of 
 molasses masse-cuites, the analysis of a first, second, and third molasses, both 
 before and after boiling, originating from the same factory, may follow here, as 
 they admit to some extent of mutual comparison. 
 
 
 Brix. 
 
 Sucrose. 
 
 Glucose. 
 
 Ash. 
 
 Water. 
 
 1st molasses before boiling 
 
 82-70 
 
 49-6 
 
 12-3 
 
 5-04 
 
 20-55 
 
 2nd 
 
 81-10 
 
 46-0 
 
 13-4 
 
 5-20 
 
 23-27 
 
 3rd „ „ „ .. .. 
 
 83-20 
 
 44-8 
 
 17-5 
 
 6-60 
 
 20-28 
 
 1st ,, after , 
 
 89-70 
 
 53-6 
 
 12-7 
 
 5-45 
 
 16-8 
 
 2nd ,, „ „ .. .. 
 
 88-40 
 
 49-6 
 
 16-0 
 
 5-30 
 
 18-3 
 
 3rd 
 
 90-70 
 
 48-5 
 
 17-9 
 
 6-87 
 
 14-10 
 
 In boiling molasses no more than five or six per cent, of water is evaporated, 
 hence liie yield in sugar from boiled molasses cannot be very considerable 
 if in cuiing the No. I sugar all the crystals were really separated from the 
 molasses. 
 
 It often happens that during the cooling down of after-product masse-cuites, 
 the surface becomes convex and eventually bursts, a brown froth oozing out of 
 the crevices. This soon covers the whole surface, rising continually, and finally 
 flowing over the bi-im of the cistern. Gases escape from this froth, emitting a 
 very unpleasant smell and having an acid reaction, the whole phenomenon being 
 called "froth-fermentation." With second and third molasses, where no hard 
 
66 
 
 crystalline crust is formed on the surface, the whole mass starts frothing from the 
 bottom, but in other respects its aspect is quite the same as with the first molasses. 
 A great deal has been said and written about this froth-fermentation, but a fully 
 reliable remedy does not appear as yet to have been found. The fact is beyond 
 doubt that it is, properly speaking, not a fermentation due to one or other minute 
 organism, and hence all efforts to combat the phenomenon by means of disinfect- , 
 ing agents are fruitless. This froth-fermentation does not, break up sugar, and as 
 the masse- cuite is puSed up by disengaged gases, crystallization takes place very 
 easily, hence suoh masse-cuites generally contain well-shaped crystals, and 
 are very readily cured in centrifugals, for which reason it is customary to say 
 that the froth changes into sugar, but this must not be taken literally. The most 
 probable hypothesis is that the frothing is caused by the spontaneous decomposi- 
 tion of products arising from the breaking up of sugar or glucose, these products 
 forming carbonic, formic, and acetic acids, humus and caramel, leaving unsettled 
 the question whether sugar or glucose has been broken up by overheating or by 
 the action of the alkalies. 
 
 The hypothesis appears plausible in view of the smell of the escaping gases, 
 and of the further fact that this fermentation has been successfully obviated by 
 steaming and skimming off the crude molasses. During this operation the 
 glucinic acid in the acid molasses is broken up at the high temperature, by which 
 means this product of decomposition is eliminated at once in the fluid molasses, 
 and the fine crystals suspended in the molasses also become dissolved. If these 
 are still present in the molasses at the time when the latter are drawn into the 
 pan, they will settle on the steam coils, interfere witlf the conduction of heat, and 
 finally, becoming overheated themselves, will give rise to troublesome products of 
 decomposition. With a view to avoid decomposition it is therefore advisable not 
 to allow the temperature in the pan to exceed 160° F. 
 
 A further proof for the thesis that froth-fermentation is to be ascribed to 
 decomposition of products of superheating, is yielded by the fact that now the 
 molasses are no more boiled repeatedly, but almost directly removed as exhausted 
 and therefore run less risk of being superheated, the froth-fermentation of late 
 years has occurred much less frequently than it used to do previously. 
 
 The reason why such masse-cuites only start frothing while cooling down, is 
 explained by the fact that the unstable bodies break up spontaneously on the 
 concentration of the solutions in which they are suspended. As a masse-cuite 
 cools down, sugar crystallizes out, the result being that the impurities are 
 accumulated in a more concentrated solution, and this promotes dissociation, 
 which, when once started, goes on steadily in the hot medium. After the cooling 
 is over it stops, and therefore the froth-fermentation is not so violent in small 
 iron tanks, which cool down rapidly, as in large ones, where the heat is retained 
 for a longer time. As has been, already observed, no sugar is decomposed by this 
 fermentation, and thus no chemical losses are to be feared, but the mechanical 
 losses may be considerable when the mass foams over the edge of the tanks on to 
 the floor. If this is prevented by only half filling them, the space disposable is 
 not completely utilized, and the capacity of the plant at this stage is diminished. 
 
67 
 
 AU these form reasons enough for trying to prevent the fermentation, even though 
 it does not attack the sucrose. 
 
 When the after-product masse-cuites are completely crystallized out, they, too, 
 are separated into molasses and crystals. When the grain is large and the crystals 
 do not stick to each other, this is efiected by centrifugalling, but in case the grain is 
 too minute, the masse-cuite is shovelled into bags made of mats, from which some 
 molasses di-ain ofl, and the remaining mixtui-e of about equal quantities of smaU 
 sugar crystals and exhausted molasses, conglomerated into a sticky mass, is sold 
 as "sack sugar," or "black stroop." 
 
 When the last masse-cuites are very sticky, presenting great hinderances to 
 crystallization, this can be promoted by carefuUy pouring on them about a foot 
 depth of water, and leaving them to stand for a month. A slow osmosis now 
 takes place ; the molasses become a Uttle more fluid by taking up water, and at the 
 same time a portion of the viscous salts diffuses into the water, whereby the 
 quotient between glucose and ash rises, and accordingly the amount of 
 crystallizing sugar is increased. In working up, the water is first removed 
 and thrown away, and then the masse-cuite is packed in bags and the molasses 
 allowed to drain off. 
 
 If the oentrifugalled second boilings can be sold at a fair price, it is advisable 
 to do so, but if they are only fetching a low price, or are quite imsaleable, then 
 we are compelled to melt them over again in the juice, and to boil them into first 
 sugar, which operation cannot be performed without loss, and in this case is 
 unavoidable. The question now arises as to which stage of the manufacture is 
 most suitable for this melting process. Some melt the second boilings in the 
 heated mill juice, by allowing the latter to flow over a sieve on which this sugar 
 is piled, as it comes out of the juice heater ; others melt it in the subsided clarified 
 juice, while others run off the syrup at a relatively low density and bring it to 
 its proper concentration by dissolving the second sugar in it. All these methods 
 have their defenders and their opponents. No loss in manufacturing is to be 
 feared from dissolving these sugars in the syrup, but then the mistake is made of 
 mixing the syrup that had been carefuUy clarified and neutralized with the (as a 
 rule) acid sugars, and contaminating it with their impurities. We can only do 
 this on condition that the syrup is afterwards thoroughly eliminated, neutralized, 
 and allowed to settle. The same must be said with regard to melting the after- 
 products in the clarified juice ; in this case also an acid and impure body is 
 dissolved in a clarified and neutralized juice, though this is preferable to melting 
 the same sugars in the syrup, because they dissolve much more readily in the 
 thin juice than in the already concentrated syrup. One drawback to this process 
 is in the incrustation of the tubes of the triple-effect by the suspended impurities 
 which settle on them during concentration. 
 
 Prom the point of view of obtaining a good clarification, the introduction of 
 the seconds into the mill-juice is the more to be recommended, as they will then 
 again be submitted to all the processes of clarification, against which may, 
 however, be set the facts of the heavier juice subsiding slowly, and of the juice 
 in the scum containing more sugar, so that more sugar is lost in the scum-cakes. 
 
68 
 
 Another metliod is by dissolving tte second-boilings in a little hot mill -juice 
 to the concentration of syrup, skimming and neutralizing, and dra-wing it into 
 the pan, in which a first-sugar masse-cuite is already half finished. The grain 
 already formed in this is suspended in a liquid, the purity of which is in no way 
 superior to that of the sugar solution just drawn in. In this way there is no loss 
 in manufacturing, tte juices are not spoiled by being mixed with inferior sugar, 
 and no objection can be brought against drawing this solution into the pan, 
 because the grain is already formed, which also would, under ordinary conditions, 
 increase at the expense of a syrup which ultimately is no purer than the solution 
 just drawn in. A good neutralization of this sugar solution is indispensable, as 
 otherwise the acid molasses remaining between the crystals of the packed sugar 
 might cause inversion and deterioration. 
 
CHAPTEE VII. 
 
 Exhausted Moilasses. 
 
 Tte syrupy liquid drained off from the first masse-cuite mixed with molasses 
 or from the sack-sugar, from which practically no sugar crystals can be obtained 
 by further boiling and cooling, is called exhausted molasses. It stUl contains, 
 besides the accumulated impurities, whether originating from the cane juice or 
 formed afterwards, a certain amount of sucrose which cannot be turned into any 
 saleable product. The non-saccharine matters in any case require a certain 
 quantity of water to remain in solution, and to allow of their being separated 
 from, the crystals, which water will, of course, also dissolve a greater or lesser 
 quantity of sucrose, which hence becomes lost. Unless we succeed, during 
 clarification, in eliminating all substances not sugar — a very improbable 
 supposition — we shall always be sure to get molasses, and hence all processes 
 claiming to make sugar without forming molasses must be consideiei prima facie 
 illusory. Good clarification and a carefully conducted rapid working up of the 
 juice will do much to reduce the quantity of non-saccharine substances, and 
 consequently also that of the molasses, but it is quite impossible to suppress 
 these completely. 
 
 As we have already previously shown, the quantity of sugar remaining 
 dissolved in the water of the molasses entirely depends on the mutual relation of 
 the various non-saccharine bodies ; a large proportion of glucose with a small 
 amount of ash causes the molasses to be poor in sugar, whilst their sugar content 
 rises, provided that the water remains the same, as soon as the quotient between 
 glucose and ash falls. It is therefore advisable not to increase unnecessarily the 
 amount of ash in the juice, especially that of the salts of organic acids, to which 
 end a careful tempering is very necessary. The disadvantage of the increase of 
 lime salts accompanpng the carbonatation process is counterbalanced by the fact 
 of this process eliminating half the non-saccharine matter, and thus also half the 
 molasses-forming bodies. It should not be forgotten that not only the percentage 
 of sucrose, but also the quantity of the molasses formed influences the loss of 
 sugar, and that everything that contributes to diminishing the quantity of the 
 molasses has a favourable effect on the output of sugar from the cane, even 
 though the amount of sugar in the molasses may perhaps be a little increased. 
 
 If, for instance, juice having a quotient of 84 is worked up, delivering an 
 exhausted molasses of 27 purity, the original juice contains 16^ of non-sugar in 
 100 parts of dry substance. By the crystallizing of the sucrose, the quantity of 
 non-sugar, the absolute amount of which may practically be considered as 
 unchanged, is raised to 73 parts in 100 parts of dry substance in the molasses. 
 The 100 parts of dry substance in the juice are at the same time reduced to 
 
 X ijj^ substance in molasses. As this contains 27 parts of sucrose on 100 
 
 to 
 
70 
 
 parts of dry substance, the loss of sucrose in molasses on 100 parts of dry substance 
 in juice bas amounted to 
 
 16 X 100 X 27 _ a, 
 73 X 100 ^' 
 
 If a juice of 92 purity bad delivered a molasses of 35 quotient tbis loss of 
 
 sucrose -would bave been 
 
 8 X 100 X 35 _ „.q, 
 65 X 100 ■" '^" 
 
 Hence we see, tbat notwithstanding the larger amount of sucrose in the 
 molasses, the absolute quantity of sucrose lost is smaller in the second case. 
 
 It may happen that a very sticky molasses, having a high saccharine content, 
 is already practically exhausted, because its nature does not admit of any further 
 evaporation, as in such case the boiled mass would become too viscous to allow of 
 crystallization . 
 
 In these cases the molasses contain so much gummy matter that one is 
 obliged to leave much water in them, lest they should coagulate into a sticky mass 
 of jeUy after evaporation and cooling. If evaporation is actually carried on to 
 this point, the crystallization is hindered, and the minute crystals can no longer 
 be separated from the adhering sticky mother liquor, thus practically preventing 
 them from being recovered. 
 
 If in order to avoid tbis the molasses are left less concentrated, too much 
 sucrose remains dissolved and does not crystallize, for which reason the loss of 
 sucrose in molasses is disproportionately heavy. Though the solubility of the 
 sugar is in any case exclusively influenced by the proportion between glucose and 
 ash, the quantity of water which we are compelled to leave in the molasses is 
 regulated by the natiu-e of the total amount of the non-saccharine bodies, because 
 in practical working the masse-cuites have always to be boUed in such a way that 
 a certain circulation remains possible. It is true tbat after higher concentration 
 more sugar crystallizes, but this takes place in such a form that it cannot be 
 separated. This accounts for the fact that in the table we find among the 
 analyses of exhausted molasses one (No. 3) having 43'7 per cent, of sucrose, while 
 a second molasses (No. 20), showing 22'42 per cent, of sucrose and a quotient of 
 purity of 30'32, still yields a little sack-sugar after evaporation and cooling. 
 Prom this it results that the chemical analysis cannot show with any reliability 
 whether or not a molasses is to be considered as exhausted ; while the amount of 
 sucrose in exhausted molasses is very variable (varying between 35 and 45 per 
 cent.), tbat of the total quantity of sucrose lost in molasses is tolerably constant, 
 viz., from 5 to 7 per cent, of the sugar entering into the factory, in which 
 calculation the molasses carried off along with the sugar crystals in the after- 
 products is not included. 
 
 The accompanying tables, where analyses obtained from various methods of 
 working are stated, may give some little idea of the composition of Java exhausted 
 molasses. These molasses are not filtered mother-lyes as in Chapter VI., but 
 technically exhausted molasses as they are removed from the factories. Some of 
 them stiU contain minute grain, which enters into their composition, and 
 accounts for the high readings for Brix met with in some instances. 
 
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 OS 
 CD 
 
 cs 
 
 CD 
 
 o 
 
 OS 
 
 CO 
 CO 
 
 OS 
 
 CS 
 
 o 
 
 00 
 
 o 
 
 o 
 
 o 
 
 •qey 
 
 CO 
 
 CO 
 
 CD 
 
 1» 
 
 Os 
 
 CO 
 
 <D 
 
 00 
 
 OS 
 
 CD 
 lO 
 
 
 o 
 
 CO 
 OS 
 
 ^ 
 
 ■9flOoni£) 
 
 OO 
 
 CO 
 
 
 CO 
 CO 
 CO 
 
 o 
 
 CO 
 
 CO 
 
 lb 
 
 CO 
 
 C3S 
 CO 
 
 o 
 
 CO 
 
 OS 
 
 eg 
 
 co 
 
 CM 
 
 o 
 
 CO 
 
 
 CO 
 
 CO 
 CO 
 
 
 
 CO 
 
 CO 
 CO 
 
 CO 
 
 OS 
 
 pq 
 
 CO 
 
 CO 
 CO 
 
 CO 
 CO 
 
 CO 
 
 OS 
 
 •«OICJ'EZfJB|Oc[ 
 
 o 
 
 CO 
 CO 
 
 o 
 
 CO 
 
 
 CD 
 
 CO 
 
 CD 
 
 o 
 
 OS 
 
 lb 
 
 o 
 
 OO 
 
 o 
 
 CD 
 
 CO 
 
 o 
 
 CO 
 
 •xua 
 
 OD 
 
 o 
 
 CO 
 
 CO 
 
 CO 
 
 CO 
 
 o 
 
 OD 
 00 
 
 o 
 
 00 
 
 CD 
 
 00 
 
 CO 
 CO 
 
 lb 
 
 CO 
 
 o 
 
 o 
 
 OO 
 
 OO 
 00 
 
 CO 
 
 •jaqtanjii 
 
 OS 
 
 CO 
 
 o 
 
 ■^ 
 
 
 CO 
 
 
 VO 
 
 CO 
 
 t- 
 
 tH 
 
 00 
 
 OS 
 
 
 -s^. 
 
 
 
 
 
 
 
 
 
 
 _ 
 
 
 
 
 
 '>ioiivoa.aa(j 
 
 
 
 
As yet no satisfactory metb.od of utilizing the molasses has been found. 
 Osmosis has proved impracticable, as the impurities are doubtless so closely 
 combined with the sugar that they do not diffuse any sooner than it does ; and, 
 further, the osmosis of cane sugar molasses goes on too slowly to give good results 
 in practical working. 
 
 Experiments made in Java with newly invented methods of sugar extraction 
 from molasses, which had proved successful with beet-molasses, failed. The high 
 content of reducing sugar was an insurmountable obstacle. The quantity of 
 molasses used for fodder is also too insignificant to deserve special mention. 
 
 The question of the use of molasses as fuel also presents difficulties, even 
 when mixed with bagasse, for at low temperature it forms a voluminous mass of 
 coal, which chokes up the grate, and at an elevated temperature the Ume and 
 alkali of the molasses combine with the silica from the bagasse, forming a kind of 
 glass which covers the grate bars, and prevents the free access of air. 
 
 For very large factories it will pay to build a special molasses furnace, as is 
 used in several cane-growing countries. This has no grate, the air enters under 
 the fuel through holes made in the walls. The molasses is poured on an iron 
 plate before the furnace, where it dries, and from whence it is shovelled into the 
 furnace. The fire is started with a little fire-wood at the outset, and once being 
 lit it is kept burning with the dried molasses. The combustion goes on perfectly, 
 the ash is fine and well-nigh free from carbon. Its great advantage is its being very 
 rich ia potash, of which constituent it contains as much as 352. Therefore it may 
 be used by glassmakers, soapmakers, or as a fertilizer. 
 
 This is such an important item, that even if the quantity of molasses is 
 too smaU to be able to feed a boiler regularly, it wUl pay to burn the molasses for 
 the sake of its ash only. 
 
 Some estates use the molasses as a fertilizer, or in order to break up rooky 
 subsoil. The molasses get sour and soften a hard subsoil, thus permitting its 
 being tilled. In other places molasses are simply poured over the earth on the 
 banks as manure. SeUing the molasses to arrack distillers is perhaps the most 
 • economical way of disposing of them ; fermenting and distilling them at the 
 factory itself is not possible in Java, because of the prohibitive excise regulations. 
 The question of what to do with the molasses is therefore stiU an open one, 
 and the only way many sugar manufacturers have of getting rid of this trouble- 
 some by-product is to throw it into the nearest stream. 
 
PART m. 
 
 Chemicals used in Ca^'e SraAB MAH-uTACTtrBE. 
 
 1. Lime. 
 
 Lime being the only clarifying agent in cane sugar manufacture, it is evident 
 that great care should be taken always to use the purest and best available, and 
 it is better to spend a little more money to procure a pure brand than to use a 
 cheap bat impure lime, as the difference in expense is so trifling that it cannot 
 enter into comparison with the heavy losses occasioned by the use of bad lime. 
 
 Factories working with the defecation process usually purchase the 600 or 
 700 cwts. of lime which they annually require ; and only few of them burn it 
 themselves from limestone or fossil coral in small kilns heated with wood. During 
 this process the carbonate of lime, which forms the principal part of the limestone, 
 becomes decomposed into qmcklime, which remains in the kiln, and carbonic acid, 
 which escapes. In factories using the carbonatation process, which requires 
 large quantities of lime, it is burned in specially constructed furnaces with coke 
 as fuel, and the gas passing off is utilized for saturation. In this case the 
 limestone is broken into pieces, mixed with coke, and thrown in at the open end 
 of the furnace, when the coke, in burning, forms carbonic acid, and by its heat 
 decomposes the limestone into lime and carbonic acid. A suction pipe, fitted in 
 the upper end of the furnace, and connected with a pump, draws ofl the carbonic 
 acid, the resulting vacuum is again occupied by the air flowing in at the grate, 
 by which means draught and combustion are maintained. Attention should be 
 paid to prevent any holes in the furnace by which air can penetrate, other than 
 the openings under the grate, as in this case the carbonic acid becomes diluted 
 with air, and combustion is retarded. The gas drawn off from the furnace 
 undergoes washing and cooling before being pumped ofi to the saturation tanks, 
 because proper carbonatation requires a pure and cold carbonic acid in order to 
 prevent any impurities being carried into the juice, and to keep the temperature 
 from rising above 140° F. 
 
 From time to time the quicklime is removed from the furnace by a door 
 under the grate, and allowed to cool, after which it is used in the factory as milk 
 of lime. The best method of slaking lime is by pouring water over it in large 
 brick tanks, and allowing both constituents to combine there, taking care to use 
 a sufficient quantity of water for the slaked Hme, after the action has ceased, to 
 be covered by about an inch of water. This .method is much better than allowing 
 the lime to be slaked by the humidity of the atmosphere, because hard lumps 
 remain unslaked, and, moreover, the lime also attracts carbonic acid from the air 
 and becomes inactive, which is avoided by its being kept under water. 
 
77 
 
 Before being used, tte slaked lime is diluted with water to 20° Beaume, 
 strained through an iron strainer, and is then ready for use. The limestone 
 selected should combine a high degree of purity with rapid combustion. The 
 crystalline lime spars are very pure, but require a large amount of fuel, and 
 therefore a soft limestone or fossU coral is to be preferred, if obtainable. 
 
 A description of a complete a,nalysis of Kme or limestone may be found in 
 any handbook of analytical chemistry, but a rapid qualitative method for 
 analyzing any kind of lime or limestone may perhaps not be out of place here. 
 
 Pour dilute hydjochloric acid on five grams of an average sample of the 
 finely powdered limestone ; this dissolves with emission of gas bubbles, leaving 
 only a few flakes of insoluble matter. The filtered solution is boiled in 
 order to drive off the carbonic acid, next, a few com. of nitric acid are added, and 
 the mixture rendered alkaline with ammonia. Iron oxide, alumina, silica, and 
 phosphate of lime are thrown down (the total amount of these possibly also not 
 exceeding a few flakes) which settle rapidly. Should the liquid become quite 
 opaque, the limestone should be rejected. 
 
 Lime may be analyzed in the following way. Water being poured on five 
 grams of the lime, the latter should swell, become hot, and quickly form a 
 voluminous mass, which contains only a few or no hard particles. If the lime 
 becomes slaked slowly or not at all, this may be in consequence of its not being 
 burned enough, or being burned " dead" owing to too high a temperature or to 
 impurities which have combined with it. 
 
 The moist slaked lime should dissolve completely and without effervescence 
 in dilute hydrochloric acid. Efiervescenoe indicates the presence of carbonic 
 acid, it either not having been completely expelled or again attracted from the 
 atmosphere ; in case the Hme dissolves slowly without effervescence it is burned 
 dead, while sand, clay, and similar impurities remain undissolved. The solution 
 is filtered, boiled, a few drops of nitric acid added, and then treated in the same 
 way as described for the examination of limestone. If it is also decided to 
 ascertain the presence of gypsum, a dilute solution of the lime or limestone in 
 hydrochloric acid is tested with a solution of chloride of barium, which yields a 
 white precipitate with the sulphate of the gypsum. For this test dilute solutions 
 are required, as concentrated hydrochloric acid also precipitates barytes from its 
 solutions, which precipitate, however, becomes dissolved on dilution, which the 
 sulphate of barium does not. 
 
 As magnesia is a very troublesome constituent when occurring in Hme used 
 for clarification, it is advisable to examine every fresh parcel by the following 
 quick method as to the magnesia contained. 
 
 One gram of the lime is dissolved in 10 com. of hot water, adding by drops 
 dilute hydrochloric acid untU nearly all the lime is dissolved, the liquid being still 
 neutral or sKghtly alkaline. If by accident this point has been passed, causing 
 the acid reaction to predominate, a little more of the lime should be thrown in, in 
 order to restore the neutral or alkaline reaction. The solution is next to be boiled 
 and filtered, and ammonia added to the filtrate. If the lime is pure the filtrate 
 
78 
 
 remains clear, but if magnesia is present white gelatinous hydroxide falls down. 
 Under the conditions here described, lime containing one per cent, of magnesia 
 yields a distinct gelatinous separation. When the precipitate is more than just 
 visible, the lime contains more than one per cent, of magnesia, and should not be 
 used for clarification. Great care must be taken that the filtered liquid is not 
 acid, because in that case, as has been shown above, the magnesia remains 
 partially or entirely in solution after the ammonia has been added. The liquid 
 should be boiled before filtering, to drive out all the carbonic acid, for if the latter 
 remained in the liquid, it would form carbonate of ammonia, which precipitates 
 carbonate of lime, and thus might cause us to assume the presence of magnesia, 
 even in pure lime. 
 
 In testing for magnesia in limestone, two grams of the finely-powdered stone 
 are boiled with 10 c.cm. of water and so much dilute hydrochloric acid, that the 
 liquid shall be neutral and contain only a very small quantity of the stone still 
 unaffected by the acid ; a few com. of lime water are added to throw down oxide 
 of iron and alumina, which are occasionally present ; the mixture is then filtered 
 and the filtrate treated with ammonia. 
 
 In doubtful cases the test with phosphate of soda after the removal of the 
 lime by oxalate of ammonia is, of course, to be preferred, but if it is desired to 
 ascertain very quickly whether a parcel of lime or limestone may be used, the 
 above described tests will render good service. 
 
 2. Phosphoric Add. 
 
 The phosphoric acid used in sugar manufacture is met with in commerce 
 either as free acid in solution or as a paste in the form of acid phosphate of Kme. 
 The first generally contains 35 to 40^ of free anhydrous phosphoric acid and 
 scarcely any acid in combination, while the acid phosphate contains 25 to 30^ of 
 free acid and about 10^ of acid neutralized by lime. The amount of free acid is 
 easily determined by titration with normal test solution of soda, in which case it 
 should be borne in mind that, using phenolphthalein as an indicator, every c.cm. 
 of the test solution neutralizes 35'5 mgr. of P2O5. Both preparations should 
 also be tested for sulphuric acid, the amount of which should be as small as 
 possible, as the gypsum dissolves in the juice and deposits itself on the tubes of 
 the evaporators in the form of a hard incrustation. 
 
 Both the free acid and the acid salt may be used, though for the purpose of 
 neutralization the pure acid is to be preferred, while the acid lime salt, on the 
 contrary, is preferable in cases where a heavy precipitate is wanted to cause 
 subsidence of a juice that does not easily settle, as with the same quantity of acid 
 more precipitate is thrown down by the acid lime salt than by the pure acid. If 
 necessary, both preparations can be made in the factory itself from the double 
 superphosphate commonly used for manuring, which is much better material for 
 making it than bones and sulphuric acid. 
 
 When making the acid lime salt, the double superphosphate is extracted with 
 as little water as possible, to prevent the gypsum from becoming dissolved, and 
 the solution is then diluted to the proper density. 
 
79 
 
 By boiling tie concentrated solution with the calculated quantity of sulphoric 
 acid, and allowing the gypsum to crystallize, the free acid can be prepared, but 
 this operation is too troublesome to be performed in a sugar factory, and should 
 be left to the chemical manufacturer. 
 
 S. Sulphurous Acid. 
 
 The best way of making sulphurous acid is by burning sulphur in an iron 
 oven, allowing fi-ee access of air. Either air may be conducted over the burning 
 sulphur, or a steam jet may be applied in the chimney by which the vapours pass 
 off, which causes a current of fresh air to pass over the burning sulphur. The 
 sulphurous acid is cooled by a stream of cold water flowing round the escape pipe ; 
 it then runs through lead or cast-iron tubes, and is admitted into the saturation 
 tanks by lead pipes, opened or closed by india-rubber check-valves. 
 
 In order to prevent formation of sulphuric acid during the combustion, the air 
 that passes over the sulphur should be previously dried, for if it be moist, sulphuric 
 acid is produced, which quickly corrodes the iron oven or the tubes. This drying 
 is effected by compelling the air to pass through a long box or tube, filled with 
 quicklime. When the sulphurous acid is once formed it may be drawn off by a 
 steam injector without fear of further oxidation. How dangerous it is to bum 
 the sulphur in moist air may be seen from an analysis of incrustations found in a 
 sulphur oven, which had only been a fortnight in use, and into which moist air 
 had been introduced for burning the sulphur : — 
 
 Sulphate of iron 68-30 
 
 Sulphuret of iron 1"10 
 
 Free sulphuric acid l'2o 
 
 Sulphur 20-77 
 
 Insoluble in hydrochl. acid 1-26 
 
 "Water 6-64 
 
 Undetermined 0-68 
 
 100-00 
 
PART IV. 
 
 TABLES, 
 
 1. Formula and Table for adjusting the Bagasse Turner for Three Roller Milk, 
 having Boilers of 26 in. to 32 in. diameter. 
 
 When the position of the rollers has been settled, so that they will crush the 
 quantity of cane corresponding with the capacity of the factory, the proper 
 adjusting of the bagasse turner may be determined, -which should properly be 
 curred in a logarithmical spiral, for which may be substituted an arc of a circle, 
 owing to the relatively small length of the turner. The construction of this is 
 made easy by the following table, in which — 
 
 E = radius of the circle of which the trash turner is an arc. 
 
 S = distance between head and feed rollers. 
 
 D = diameter of the rollers. 
 
 Angle a = constant angle of spiral. 
 
 
 For a 
 
 Distance S op 2 to 4 Inches. 
 
 
 D. 
 
 Diameter 
 
 of the Boilers 
 
 in inches. 
 
 D. 
 
 Diameter 
 
 of the EollerB 
 
 in mm. 
 
 Angle 1*. 
 
 R. 
 
 In Inches. 
 
 E. 
 In mm. 
 
 26 
 
 660 
 
 83° — 81° 
 
 13if-13ii 
 
 345 — 352 
 
 27 
 
 686 
 
 83° — 81° 
 
 14A-14t% 
 
 360 — 365 
 
 28 
 
 712 
 
 83° 30' — 81° 30' 
 
 14ii-14i| 
 
 370 — 378 
 
 29 
 
 738 
 
 83° 30' — 81° SO' 
 
 15,V-15tV 
 
 385 — 392 
 
 30 
 
 762 
 
 84° — 82° 
 
 15if-15if 
 
 395 — 404 
 
 31 
 
 788 
 
 84° — 82° 
 
 16TV-16T^e 
 
 409 — 416 
 
 32 
 
 814 
 
 84° 30' — 83° 
 
 161^-17 
 
 423 — 430 
 
 In this table the greatest angles concur with the lowest values for S, and the 
 lowest figures for E with the lowest for S. 
 
 The construction is eSeoted as follows : — 
 
 Draw the exact position of the rollers to scale, join the centres of the head 
 and feed rollers, draw the angle a (generally = 83°), beginning at the point A, 
 causing angle H A B to be 83°. Now draw A perpendicular to A B and H 
 perpendicular to A 0, when wiU be the centre of the circle, having the radius 
 A C := E, of which the trash turner is an arc. 
 
81 
 
 2. Table allowing the Solubility of Sucrose in Water, from (f to lOOP, according 
 
 to A. Hwzfdd* 
 
 
 Per cent. 
 
 
 Per cent. 
 
 
 Per cent. 
 
 Temp. 
 
 of Snoroae. 
 
 Temp. 
 
 of Sucrose. 
 
 Temp. 
 
 of Sucrose. 
 
 
 
 . . . . 64-18 
 
 20 . 
 
 . . . 67-09 
 
 40 .. 
 
 . . 70-42 
 
 1 
 
 . . . 64-30 
 
 21 . 
 
 . . . 67-25 
 
 41 .. 
 
 . . 70-60 
 
 2 
 
 . . . 64-45 
 
 22 . 
 
 . . . 67-41 
 
 42 .. 
 
 . . 70-78 
 
 3 
 
 . . . 64-59 
 
 23 . 
 
 ... 67-57 
 
 43 .. 
 
 . . 70-96 
 
 4 
 
 . . . 64-73 
 
 24 . 
 
 . . . 67-73 
 
 44 .. 
 
 . . 71-14 
 
 
 
 . . . 64-87 
 
 25 . 
 
 67-89 
 
 45 .. 
 
 .. 71-32 
 
 6 
 
 . . . 6501 
 
 26 . 
 
 . . . 68-05 
 
 46 .. 
 
 . . 71-50 
 
 7 
 
 ... 65-15 
 
 27 . 
 
 . . 68-21 
 
 47 .. 
 
 .. 71-68 
 
 8 
 
 . . . 65-29 
 
 28 . 
 
 . . . 68-37 
 
 48 .. 
 
 .. 71-87 
 
 9 
 
 . . . 65-43 
 
 29 . 
 
 . . . 68-53 
 
 49 .. 
 
 . . 7206 
 
 10 
 
 . . . 65-58 
 
 30 . 
 
 . . . 68-70 
 
 50 .. 
 
 . . 72-25 
 
 11 
 
 . . . 65-73 
 
 31 . 
 
 . . . 68-87 
 
 61 .. 
 
 . . 72-44 
 
 12 
 
 . . . 65-88 
 
 32 . 
 
 . . . 69-04 
 
 52 .. 
 
 . . 72-63 
 
 13 
 
 . . . 66-03 
 
 33 . 
 
 . . . 69-21 
 
 53 .. 
 
 . . 72-82 
 
 14 
 
 . . . 66-18 
 
 34 . 
 
 . . . 69-38 
 
 54 .. 
 
 .. 73-01 
 
 15 
 
 . . . 66-33 
 
 35 . 
 
 . . . 69-55 
 
 55 .. 
 
 . . 73-20 
 
 16 
 
 . . . 66-48 
 
 36 . 
 
 ... 69-72 
 
 56 .. 
 
 . . 73-39 
 
 17 
 
 . . . 66-63 
 
 37 . 
 
 . . . 69-89 
 
 57 .. 
 
 . . 73-58 
 
 18 
 
 . . . 66-78 
 
 38 . 
 
 , . . 70-06 
 
 58' .. 
 
 . . 73-78 
 
 19 
 
 . . . 66-93 
 
 39 . 
 
 . . . 70-24 
 
 59 . 
 
 . . 73-98 
 
 • Zeitsolirift f. d. EUbenzuokerindustrie, 1892, page 181. 
 
82 
 
 Tabk showing the Solubility of Sucrose in Water, from CP to 100', acccording 
 to A. Herzfdd. — Continued. 
 
 
 Per cent. 
 
 Temp. 
 
 of Bucrose 
 
 60 
 
 ... 74-18 
 
 61 
 
 . . . 74-38 
 
 62 
 
 . . . 74-58 
 
 63 
 
 . . . 74-78 
 
 64 
 
 . . . 74-98 
 
 65 
 
 ... 75-18 
 
 66 
 
 . . . 75-38 
 
 67 
 
 . . . 75-59 
 
 68 
 
 ... 75-80 
 
 69 
 
 . . . 76-01 
 
 70 
 
 . . . 76-22 
 
 71 
 
 . . . 76-43 
 
 72 
 
 . . . 76-64 
 
 73 
 
 . . . 76-85 
 
 
 Per cent. 
 
 Temp. 
 
 of Sucrose 
 
 74 .. . 
 
 77-06 
 
 75 ... 
 
 77-27 
 
 76 .. 
 
 77-48 
 
 77 ... 
 
 77-70 
 
 78 ... 
 
 77-92 
 
 79 ... 
 
 78-14 
 
 80 ... 
 
 78-36 
 
 81 ... 
 
 78-58 
 
 82 ... 
 
 78-80 
 
 83 ... 
 
 79-02 
 
 84 ... 
 
 79-24 
 
 85 ... 
 
 79-46 
 
 86 ... 
 
 79-69 
 
 87 ... 
 
 79-92 
 
 ubility: y 
 
 = 84-183 
 
 
 Per cent. 
 
 emp. 
 
 of Sucrose 
 
 88 .. 
 
 . . 80-15 
 
 89 .. 
 
 . . 80-38 
 
 90 .. 
 
 . . 80-61 
 
 91 .. 
 
 . . 80-84 
 
 92 
 
 . . 81-07 
 
 93 .. 
 
 .. 81-30 
 
 94 .. 
 
 . . 81-53 
 
 95 .. 
 
 .. 81-77 
 
 96 .. 
 
 . . 82-01 
 
 97 .. 
 
 . . 82-25 
 
 98 .. 
 
 . 82-49 
 
 99 .. 
 
 . . 82-73 
 
 00 .. 
 
 .. 82-79 
 
 Q-eueral formula for tlie solubility : y = 84-1835 X 0-13477 x X 0-0005307 x^ 
 :per cent, of sugar and x = temp, in degrees 0. 
 
 3. Table showing the Specific Gravity of Milk of Lime according to 
 Lunge and Blattner. 
 
 Degrees 
 Beaume. 
 
 Grrams of Weight of 
 CaO in 1 litre of 
 1 Litre. Milk of Lime. 
 Sr. 
 
 Degrees 
 Beaume. 
 
 G-rams of 
 CaO in 
 1 Litre. 
 
 Weight of 
 
 1 Litre of 
 
 Milk of Lime 
 
 Gr. 
 
 1 . 
 
 7-6 ... 
 
 1007 
 
 16 .. 
 
 .. 159 
 
 ... 1125 
 
 2 . 
 
 .. 16-5 ... 
 
 1014 
 
 17 .. 
 
 . . 170 
 
 . . . 1134 
 
 3 . 
 
 . . 26 
 
 1022 
 
 18 .. 
 
 .. 181 
 
 . . . 1142 
 
 4 . 
 
 . . 36 
 
 1029 
 
 19 .. 
 
 .. 193 
 
 ... 1152 
 
 5 . 
 
 . . 46 
 
 1037 
 
 20 .. 
 
 .. 206 
 
 ... 1162 
 
 6 . 
 
 . . 56 
 
 1045 
 
 21 .. 
 
 .. 218 
 
 ... 1171 
 
 7 . 
 
 . . 65 
 
 1052 
 
 22 .. 
 
 .. 229 
 
 , . . 1180 
 
 8 . 
 
 75 ... 
 
 1060 
 
 23 .. 
 
 .. 242 
 
 . . . 1190 
 
 9 . 
 
 . . 84 
 
 1067 
 
 24 .. 
 
 .. 255 
 
 1200 
 
 10 . 
 
 . . 94 
 
 1075 
 
 25 .. 
 
 .. 268 
 
 ... 1210 
 
 11 . 
 
 .. 104 
 
 1083 
 
 26 .. 
 
 .. 281 
 
 . . . 1220 
 
 12 . 
 
 .. 115 
 
 1091 
 
 27 .. 
 
 .. 295 
 
 . . . 1231 
 
 13 . 
 
 .. 126 
 
 1110 
 
 28 .. 
 
 .. 309 
 
 . . 1241 
 
 14 . 
 
 . . 137 
 
 1108 
 
 29 .. 
 
 .. 324 
 
 . . . 1252 
 
 15 . 
 
 .. 14S 
 
 1116 
 
 30 .. 
 
 .. 339 
 
 . . . 1263 
 
83 
 
 k. .Specific Gravity of Soda Solutiom at S8° C. (82-!fF.J 
 
 Percentage 
 of Sods. 
 
 Specific gravity 
 
 of a percentage of 
 
 Na^O. NaOH. 
 
 1 .. 
 
 . 1-012 . 
 
 
 009 
 
 2 .. 
 
 . 1-027 , 
 
 
 020 
 
 3 .. 
 
 . 1-040 . 
 
 
 032 
 
 4 .. 
 
 . 1-055 . 
 
 
 043 
 
 5 .. 
 
 . 1-071 . 
 
 
 056 
 
 6 .. 
 
 . 1-086 . 
 
 
 067 
 
 7 .. 
 
 . 1-111 . 
 
 
 078 
 
 ' 8 ,. 
 
 . 1-116 . 
 
 
 089 
 
 9 .. 
 
 . 1-129 . 
 
 
 100 
 
 10 .. 
 
 .. 1-142 . 
 
 
 112 
 
 11 .. 
 
 .. 1-158 . 
 
 
 123 
 
 12 .. 
 
 .. 1-172 . 
 
 
 133 
 
 13 .. 
 
 . 1-187 . 
 
 
 145 
 
 14 .. 
 
 . 1-200 . 
 
 
 156 
 
 15 .. 
 
 . 1-215 . 
 
 
 167 
 
 16 .. 
 
 . 1-230 . 
 
 
 178 
 
 17 .. 
 
 . 1-241 . 
 
 
 184 
 
 18 .. 
 
 . 1-254 . 
 
 
 198 
 
 19 .. 
 
 . 1-266 . 
 
 
 209 
 
 20 .. 
 
 . 1-281 . 
 
 
 221 
 
 21 .. 
 
 . 1-269 . 
 
 
 234 
 
 22 .. 
 
 . 1-311 . 
 
 
 243 
 
 23 .. 
 
 . 1-325 . 
 
 
 254 
 
 24 .. 
 
 .. 1-337 . 
 
 
 265 
 
 25 .. 
 
 . 1-351 . 
 
 
 275 
 
 26 .. 
 
 . 1-365 . 
 
 
 286 
 
 27 .. 
 
 . 1-374 . 
 
 
 296 
 
 28 .. 
 
 . 1-391 . 
 
 
 306 
 
 29 .. 
 
 . 1-416 . 
 
 
 317 
 
 30 .. 
 
 . 1-420 . 
 
 
 328 
 
 It is self-evident that the above figures 
 only the substances mentioned, hence only 
 
 Percentage 
 of Soda. 
 
 Specific gravity 
 
 of a percentage of 
 
 Na^O. NaOH. 
 
 31 ... 1 
 
 434 .... 1-339 
 
 32 ... 
 
 
 446 ... 
 
 1-347 
 
 33 ... 
 
 
 458 ... 
 
 1-359 
 
 34 ... 
 
 
 471 ... 
 
 1-370 
 
 35 ... 
 
 
 484 ... 
 
 1-380 
 
 36 ... 
 
 
 496 ... 
 
 1-391 
 
 37 ... 
 
 
 511 ... 
 
 1-401 
 
 38 ... 
 
 
 526 ... 
 
 1-411 
 
 39 
 
 
 539 ... 
 
 1-422 
 
 40 ... 
 
 
 554 ... 
 
 1-433 
 
 41 ... 
 
 
 566 ... 
 
 1-443 
 
 42 ... 
 
 
 579 ... 
 
 1-452 
 
 43 .. 
 
 
 593 ... 
 
 1-464 
 
 44 ... 
 
 
 606 ... 
 
 1-474 
 
 45 ... 
 
 
 617 ... 
 
 . 1-484 
 
 46 ... 
 
 
 -632 . . . 
 
 . 1-495 
 
 47 ... 
 
 
 645 ... 
 
 . 1-503 
 
 48 ... 
 
 
 -658 . . . 
 
 . lol4 
 
 49 ... 
 
 
 673 ... 
 
 1-524 
 
 50 ... 
 
 
 .685 . . . 
 
 1-535 
 
 51 ... 
 
 
 700 ... 
 
 . 1-545 
 
 52 ... 
 
 
 -714 . . . 
 
 1-555 
 
 53 ... 
 
 
 725 ... 
 
 . 1-565 
 
 54 ... 
 
 
 740 ... 
 
 1-575 
 
 55 ... 
 
 
 755 ... 
 
 1-586 
 
 56 ... 
 
 
 770 .. 
 
 1-596 
 
 57 ... 
 
 
 780 ... 
 
 1-606 
 
 58 ... 
 
 
 795 ... 
 
 1-617 
 
 59 ... 
 
 
 -810 . . . 
 
 1-628 
 
 60 ... 
 
 1-825 . . . 
 
 1-638 
 
 are only exact for solutions containing 
 
 for pure soIl 
 
 ition 
 
 s. 
 
 
 Specific Qrai-ity of Solution of Carbonate of Soda at S8^ C. 
 (82-5° F.J according to Schiff. 
 
 Specific 
 gravity. 
 
 1-0038 . 
 
 Percentage of the 
 Solution of 
 Na^COs. 
 
 10 HaO. IfajCOa. 
 
 1 .... 0-370 
 
 Specific 
 gravity. 
 
 1-0191 . 
 
 Percentage of the 
 Solution of 
 NaaOOj. 
 10 HjO. Na>CO 
 
 5 .. 1-853 
 
 1-0076 . 
 
 . .. 2 .... 0-741 
 
 1-0231 . 
 
 6 .... 2-223 
 
 1-0114 . 
 
 3 .... 1-112 
 
 1-0270 . 
 
 . .. 7 .... 2-594 
 
 1-0153 . 
 
 4 ... 1-482 
 
 1-0309 . 
 
 . . . 8 .... 2-965 
 
84 
 
 Specific Gravity of Solution of Carbonate of Soda at 28° G. 
 f8S'5°F.J according to Schiff. — Continued. 
 
 Percentage of the 
 Solution of 
 
 Specific NaaCOa. 
 
 gravity. 10 H2O. Sbl^CO^. 
 
 1-0348 ... 9 .... 3-335 
 
 1-0388 .... 10 .... 3-706 
 
 1-0428 .... 11 .... 4-076 
 
 1-0468 .... 12 .... 4-447 
 
 1-0508 .... 13 .... 4-817 
 
 1-0548 . . 14 .... 5-188 
 
 1-0588 15 5-558 
 
 1-0628 .... 16 ... 5-929 
 
 1-0668 .... 17 .... 6-299 
 
 1-0708 ... 18 6-670 
 
 1-0748 .... 19 .... 7-041 
 
 1-0789 .... 20 .... 7-412 
 
 1-0830 .... 21 .... 7-782 
 
 1-0871 .... 22 .... 8-153 
 
 1-0912 .... 23 .... 8-523 
 
 1-0953 . . 24 .... 8-894 
 
 1-0994 25 .. 9-264 
 
 1-1035 .... 26 .... 9-635 
 
 1-1076 .... 27 . .' . 10-006 
 
 1-1117 .... 28 .... 10-376 
 
 1-1158 .... 29 .... 10-746 
 
 Specific 
 gravity. 
 1-1200 ... 
 
 1-1242 ... 
 
 1-1284 ... 
 
 1-1326 .. 
 
 1-1368 . . . 
 
 1-1410 ... 
 
 1-1452 . . . 
 
 1-1494 ... 
 
 1-1536 ... 
 
 1-1578 ... 
 
 1-1620 ... 
 
 1-1662 . . . 
 
 1-1704 . . . 
 
 1-1746 ... 
 
 1-1788 ... 
 
 1-1830 . . . 
 
 1-1873 ... 
 
 1-1916 ... 
 
 1-1959 . . . 
 
 1-2002 . . . 
 
 1-2045 ... 
 
 PercentD 
 Solut 
 Na,03. 
 10 HjO. 
 30 . . . . 
 
 ge of the 
 ion of 
 
 Ifa^OOs. 
 11-118 
 
 31 ... 
 
 11-488 
 
 32 . , . 
 
 11-859 
 
 33 ... 
 
 12-230 
 
 34 ... 
 
 12-600 
 
 35 ... 
 
 12-971 
 
 36 ... 
 
 13-341 
 
 37 ... 
 
 13-712 
 
 38 ... 
 
 14-082 
 
 39 ... 
 
 14-463 
 
 40 ... 
 
 14-824 
 
 41 ... 
 
 15-195 
 
 42 ... 
 
 15-566 
 
 43 ... 
 
 15-936 
 
 44 ... 
 
 16-307 
 
 45 ... 
 
 16-677 
 
 46 ... 
 
 17-048 
 
 47 ... 
 
 . 17-418 
 
 48 ... 
 
 17-789 
 
 49 ... 
 
 18-159 
 
 50 ... 
 
 18-530 
 
 6. Specific Gravity of pure Solution of Phosphoric Acid at S8° 0. 
 C82-5° F.J 
 
 Specific 
 
 Gravity. 
 
 Percentage of the 
 Solution of 
 
 H3PO,. P,0,. 
 
 Specific 
 Gravity. 
 
 Percentage of the 
 Solution of 
 H3PO,. P,0,. 
 
 1-0024 . . 
 
 .. 1 .... 0-726 
 
 1-0781 . . . 
 
 14 .... 10-164 
 
 1-0079 . 
 
 .. 2 .... 1-452 
 
 1-0844 . . . 
 
 15 
 
 
 10-890 
 
 1-0134 .. 
 
 3 .... 2-178 
 
 1-0907 ... 
 
 16 
 
 
 11-616 
 
 1-0190 .. 
 
 .. 4 ... 2-904 
 
 1-0970 ... 
 
 17 
 
 
 12-342 
 
 1-0246 .. 
 
 .. 5 .... 3-630 
 
 1-1032 . , . 
 
 18 
 
 
 13-068 
 
 1-0303 .. 
 
 6 4-356 
 
 1-1097 ... 
 
 19 
 
 
 13-794 
 
 1-0360 .. 
 
 7 .... 5-082 
 
 1-1163 ... 
 
 20 
 
 
 14-620 
 
 1-0419 . . 
 
 .. 8 .... 5-808 
 
 1-1208 .. 
 
 21 
 
 
 15-246 
 
 1-0478 .. 
 
 9 .... 6-534 
 
 1-1296 . . . 
 
 22 
 
 
 15-972 
 
 1-0537 .. 
 
 .. 10 .... 7-260 
 
 1-1364 . . . 
 
 23 
 
 
 16-698 
 
 1-0597 .. 
 
 .. 11 .... 7-986 
 
 1-1432 ... 
 
 24 
 
 
 17-424 
 
 1-0658 .. 
 
 . . 12 .... 8-712 
 
 1-1601 ... 
 
 26 
 
 
 18-160 
 
 1-0719 ., 
 
 . 13 .... 9-438 
 
 1-1571 ... 
 
 26 
 
 
 18-876 
 
85 
 
 Specific Gravity of pure Solution of Phosphoric 
 {82-5° F.)— Continued. 
 
 Specific 
 Gravity, 
 
 H3 P0>. 
 
 Percentage of the 
 Solution of 
 
 ■1641 . 
 
 ... 27 
 
 
 •1712 
 
 . .. 28 
 
 
 ■1784 . 
 
 . .. 29 
 
 
 •1856 . 
 
 ... 30 
 
 
 •1928 . 
 
 ... 31 
 
 
 •2000 
 
 ... 32 
 
 
 •2073 . 
 
 ... 33 
 
 
 •2148 . 
 
 ... 34 
 
 
 •2224 . 
 
 . .. 35 
 
 
 •2298 . 
 
 ... 36 
 
 
 ■2375 . 
 
 . .. 37 
 
 
 •2453 . 
 
 ... 38 
 
 
 •2532 . 
 
 . .. 39 
 
 
 •2611 
 
 ... 40 
 
 
 •2698 . 
 
 ... 41 
 
 
 •2772 . 
 
 . .. 42 
 
 
 •2854 . 
 
 . .. 43 
 
 
 19^602 
 20^328 
 21^054 
 21-780 
 22-506 
 23-232 
 23-958 
 24-664 
 25-410 
 26^136 
 26^862 
 27^588 
 28^314 
 29^040 
 29^766 
 30-492 
 31-218 
 
 SpeciHc 
 Gravity. 
 
 ■2936 
 ■3018 
 -3102 
 ■3186 
 ■3273 
 ■3358 
 ■3445 
 ■3532 
 ■3620 
 ■3718 
 ■3808 
 ■3899 
 ■3980 
 ■4072 
 ■4165 
 ■4259 
 •4353 
 
 Acid at 28 
 
 ° 0. 
 
 Percentage of the 
 Solution of 
 H3 PO:. P, 0,. 
 . . 44 .... 31^944 
 
 . . 45 . . 
 
 . . 32^670 
 
 . . 46 . . 
 
 . . 33-496 
 
 . . 47 . . 
 
 . . 34-222 
 
 . . 48 . . 
 
 . . 34-948 
 
 . . 49 . . 
 
 . . 35^674 
 
 . . 50 . . 
 
 . , 36-400 
 
 . 51 
 
 . . 37-126 
 
 . . 52 . . 
 
 . . 37^852 
 
 . . 53 . . 
 
 . . 38^578 
 
 . 54 .. 
 
 . . 39^304 
 
 . 55 .. 
 
 . , 40-030 
 
 . . 56 . . 
 
 . . 40-756 
 
 . . 67 . . 
 
 .. 41-482 
 
 . . 58 . . 
 
 . . 42-208 
 
 . . 59 . . 
 
 . . 42-934 
 
 . 60 .. 
 
 . . 43-660 
 
 7. Relation hetweeii degrees Celsius and Fahrenheit, 
 N degrees C. = 32 + A degrees P. 
 N degrees F. = | (N-32) degrees 0. 
 
 c. 
 
 F. 
 
 C. 
 
 F. 
 
 C. 
 
 F. 
 
 c. 
 
 P. 
 
 . 
 
 32- 
 
 15 . 
 
 59- 
 
 30 . 
 
 86^ 
 
 45 
 
 . 113- 
 
 1 . 
 
 33^8 
 
 16 . 
 
 60^8 
 
 31 . 
 
 87^8 
 
 46 
 
 . 114-8 
 
 2 . 
 
 35-6 
 
 17 . 
 
 62^6 
 
 32 . 
 
 89^6 
 
 47 
 
 116-6 
 
 3 . 
 
 37^4 
 
 18 . 
 
 64-4 
 
 33 . 
 
 9Vi 
 
 48 
 
 . 118-4 
 
 4 . 
 
 392 
 
 19 . 
 
 66-2 
 
 34 , 
 
 93^2 
 
 49 
 
 . 120-2 
 
 5 . 
 
 41- 
 
 20 . 
 
 68- 
 
 35 . 
 
 95^ 
 
 50 
 
 . 122- 
 
 6 . 
 
 42-8 
 
 21 . 
 
 69-8 
 
 36 . 
 
 96-8 
 
 51 
 
 123-8 
 
 7 . 
 
 44^6 
 
 22 . 
 
 71-6 
 
 37 . 
 
 98-6 
 
 52 
 
 . 125-6 
 
 8 . 
 
 46^4 
 
 23 . 
 
 73-4 
 
 38 
 
 . 100^4 
 
 53 
 
 . 127-4 
 
 9 . 
 
 48^2 
 
 24 . 
 
 75-2 
 
 39 . 
 
 . 102-2 
 
 54 
 
 . 129-2 
 
 10 . 
 
 50^ 
 
 25 . 
 
 77- 
 
 40 . 
 
 . 104- 
 
 55 
 
 . 131- 
 
 11 . 
 
 5P8 
 
 26 . 
 
 78^8 
 
 41 . 
 
 . 105-8 
 
 86 
 
 . 132-8 
 
 12 
 
 53-6 
 
 27 . 
 
 80-6 
 
 42 . 
 
 . 107-6 
 
 57 
 
 . 134-6 
 
 13 .. 
 
 55-4 
 
 28 . 
 
 82^4 
 
 43 . 
 
 . 109-4 
 
 58 
 
 . 136-4 
 
 14 .. 
 
 57-2 
 
 29 . 
 
 84^2 
 
 44 . 
 
 . 111-2 
 
 59 
 
 . 138-2 
 
 6a 
 
86 
 
 Relation between degrees Celsius and Fahrenheit. — Continued. 
 
 c. 
 
 P. 
 
 C. 
 
 F. 
 
 C. 
 
 F. 
 
 c. 
 
 F. 
 
 60 . 
 
 . 140' 
 
 71 . 
 
 . 159-8 
 
 82 . 
 
 179-6 
 
 93 . 
 
 . 199-4 
 
 61 . 
 
 . 141-8 
 
 72 . 
 
 . 161-6 
 
 83 . 
 
 181-4 
 
 94 . 
 
 . 201-2 
 
 62 . 
 
 . 143-6 
 
 73 . 
 
 . 163-4 
 
 84 . 
 
 183-2 
 
 95 . 
 
 . 203- 
 
 63 . 
 
 . 145-4 
 
 74 . 
 
 . 165-2 
 
 85 . 
 
 185- 
 
 96 . 
 
 . 204-8 
 
 64 . 
 
 . 147-2 
 
 75 . 
 
 . 167- 
 
 86 . 
 
 186-8 
 
 97 . 
 
 . 206-6 
 
 65 . 
 
 . 149- 
 
 76 . 
 
 . 168-8 
 
 87 . 
 
 188-6 
 
 98 . 
 
 . 208-4 
 
 66 . 
 
 . 150-8 
 
 77 . 
 
 . 170-6 
 
 88 . 
 
 190-4 
 
 99 . 
 
 . 210-2 
 
 67 . 
 
 . 152-6 
 
 78 . 
 
 . 172-4 
 
 89 . 
 
 192-2 
 
 100 . 
 
 . 212- 
 
 68 . 
 
 . 154-4 
 
 79 . 
 
 . 174-2 
 
 90 . 
 
 194- 
 
 
 
 69 . 
 
 . 156-2 
 
 80 . 
 
 . 176- 
 
 91 . 
 
 195-8 
 
 
 
 70 . 
 
 . 158- 
 
 81 . 
 
 . 177-8 
 
 92 . 
 
 197-6 
 
 
 
INDEX. 
 
 PAOB 
 
 Acetic Acid 7 10 
 
 Acids, Organic, 9 ; Action on Sucrose, 5 ; on Dextrose 7 
 
 Adjusting of the Bagasse Turner, 80 ; Table and Formula for 80 
 
 Advantages of Carbonatation, 37 ; of Crystallization in Movement, 56 ; of 
 
 DifEusion 21 
 
 Agents of Clarification gy 
 
 Albumen jU 
 
 Alkalies, 5 ; Action on Dextrose, 7 ; on Levulose, 8 ; on Sucrose 5 
 
 Analysis of Cane Ash, 12 ; of Defecated Juice, 26 ; of Scums, 25 ; of Masae-cuite, 50, 
 51, 57, 58; of MillJuice, 24, 3t; of Molasses, 63; of Molasses, Masse-cuite, 65, 
 
 of Press-cakes 34. 
 
 Apoglucinic Acid 7 
 
 Apparatus for Crystallization in Movement 55 
 
 Ash Analysis j2 
 
 Asparagine 10 
 
 Aspartic Acid 1q 
 
 Bagasse, Loss of Sugar in 17, 80 
 
 Bagasse Turner 16 
 
 Barytes 39 
 
 BoUing Grain, 47 ; Smooth 53 
 
 Burning Lime 76 
 
 Butyric Acid Fermentation 6 
 
 Cane-crusher 16 
 
 Oine-cutteT 16 
 
 Cane-shredder 16 
 
 Cane-wax 11 
 
 Ciuamel 4 
 
 Oirbonatation, 33 ; Single, 3S ; Double, 36 ; Advantages 37 
 
 Oarbonatation Boxes 36 
 
 Carbonated Juice 35 
 
 Carbonate of Sodium, 39 ; Table showing its Specific Gravity 83 
 
 Carbonic Acid 33 
 
 Cell Wall, DifEusion through it 20 
 
 Centrifugals 59 
 
 Chloride of Aluminium 39 
 
 Chloride of Calcium 39 
 
 Chloride of Zino 39 
 
 Circulation in the Yacnum Pan 43 
 
11. INDEX. 
 
 PAGE 
 
 Citric Acid 59 
 
 Clarification of Mill Juice, 25, 67 ; of Syrup, 45 ; of Molaasea 62 
 
 Clarified Juice 28 
 
 Gleaning Triple Effet 44 
 
 Colouring Matter of the Cane 10 
 
 Condensed Steam, 43 ; Examination 44 
 
 Constituents of the Cane 13 
 
 Copperwall 42 
 
 Covering with Clairce ; with Steam ; with Water 59 
 
 Crystallization in Movement, 55 ; Advantages, 56 ; Apparatus 65 
 
 Crystallization of After-products 62 
 
 Curing of First Sugar ; of Seconds • 54 
 
 Cutters (Cane) .. .. 16 
 
 Cutting the Pan \. 49 
 
 Cuttings used for Seed 3 
 
 Decomposition of Dextrose, 7 ; of Glucinic Acid, 7 ; of Sucrose 4 
 
 Defecation 25 
 
 Defecation Fans 28 
 
 Defecated Juice 29 
 
 Deming's Apparatus 29 
 
 Dextrose, Preparation, 6 ; Melting Point, 6 ; Solubility, 6 ; Polarization, 6 ; 
 
 Decomposition hy Heat, 7 ; hy Alkalies, 7 ; by Acids 7 
 
 Difference in Constitution of Juice crushed by mills of different power 14 
 
 Diffusion 19 
 
 Diffusion Juice 21 
 
 Dilution on Diffusion, 21 ; on Maceration 22 
 
 Distribution of the Constituents of the Cane 13 
 
 Drawing Molasses in First Masse-cuites 51 
 
 Drying of Sugar 60 
 
 Elimination of Juice, 20 ; of Molasses, 62 ; of Syrup 45 
 
 Evaporation in Vacuo, 42 ; during Clarification 47 
 
 Examination of Limestone, 76; of Lime 77 
 
 Exhausted Molasses 69 
 
 Extraction of the Juice 15 
 
 Extraction of Sugar from Molasses , 63 
 
 False Grain 49, 54, 59 
 
 Ferments, Action on Dextrose, 8 ; on Molasses, 62 ; on Sucrose , . 6 
 
 Fibre (Cane) 11 
 
 Fibrovascular Bundles IS 
 
 Filters, Juice, 39; Scum 41 
 
 Filter-press 41 
 
 Filter-press Cakes, Analysis 34 
 
 Filtration 39 
 
INBEX. 
 
 Fletcher Pan 28 
 
 Formic Acid , r 
 
 Formula for the Proper Adjusting of the Bagasse Turner 80 
 
 Froth Fermentation gg 
 
 Fuel, Molasses as yg 
 
 Grlucosasone g g 
 
 Glucose, 9 ; Determination ^ 
 
 Q-lucinate of lime 34 
 
 Gluoinio Acid 7 
 
 Glycolic Acid 9 
 
 Grain, Boiling to.. 47 
 
 Guanine jg 
 
 Harvesting of the Gane 3 
 
 Heat, Action on Dextrose, 7 ; Levulose, 8 ; Sucrose 4 
 
 History of the Sugar Cane 1 
 
 Humus Substances 5 
 
 Hydrosulphurous Acid 38 
 
 Inversion of Sucrose, hy Acids, S ; hy Ferments, 6 ; by Heat 4 
 
 Invert Sugar g 
 
 Juice Filters 39 
 
 Lactic Acid g 
 
 Lactic Acid Fermentation 6 
 
 Leuconostoc Mesenterio'ides 6 
 
 Levulosan • • 4, 8 
 
 Levulose, 8 ; Solubility, 8 ; Polarization, 8 ; Decomposition by Heat, 8 ; by 
 
 Alkalies 8 
 
 Lime, 76 ; Burning, 76 ; Slaking, 76 ; Examination 77 
 
 Lime Furnace 76 
 
 Limestone, Examination 76 
 
 Loss of Sugar in Bagasse, 17 ; in Filter-press Cakes, 34 ; in Molasses 69 
 
 Maceration, 17; Begulating the 18 
 
 Magnesia, 77 : Detection in Lime, 77 ; in Limestone 78 
 
 MaUc Acid S, 9 
 
 Masse-cuite, 49 ; Analysis 60, 51 
 
 Maturity of the Cane 3 
 
 Melassinic Acid .. 7 
 
 Melting of Second Sugars 67 
 
 Milk of Lime, Table of Specific Gravity 82 
 
 Mills 15 
 
 Molasses, 61 ; Analysis, 63, 71, 72, 73, 74 ; Use 75 
 
IT. INDEX. 
 
 PAGE 
 
 Origin of the Cane 1 
 
 Osmosis 67, 75 
 
 Peotine 11,29 
 
 Phosphate of Calcium 25 
 
 Phosphoric Acid 37, 78 
 
 Planting Sugar Cane 3 
 
 Polarization of Sucrose, i ; of Dextrose, 6 ; of Levulose, 8 ; of Invert Sugar . . 9 
 
 Pressing Scum Filter Cates 41 
 
 Propagation of the Sugar Cane 2 
 
 Protoplasm 13 
 
 Pug Mill 60 
 
 Saccharates 5 
 
 Saccharinio Acid 7 
 
 Sack Sugar 67 
 
 Salts, 5 ; Combination with Sugar, 6 ; Action on Sucrose 6 
 
 Saturation with Carbonic Acid, 34 ; and with Sulphurous Acid 36 
 
 Scum 25, S3 
 
 Scum Filters 41 
 
 Seed of Sugar Cane 3 
 
 Skimming Clarified Juice, 28 ; Molasses 63 
 
 Slaking Lime 76 
 
 Soda, 38 ; Table of Specific Gravity 83 
 
 Sodium, Carbonate of, 39 ; Table of Specific Gravity 83 
 
 Solubility of Sucrose, 4 ; Dextrose, 6 ; Levulose 8 
 
 Sourness of Syrup 46 
 
 Steam, Covering with 59 
 
 Steaming of the Vacuum Pan 49 
 
 Subsiding of Clarified Juice, 27 ; of Syrup 45 
 
 Subsiding Tanks 28 
 
 Succinic Acid 9 
 
 Sucrose Solubility, 4 ; Crystal, 4 ; Specific Gravity, 4 ; Polarization, 4 ; Melting 
 Point, 4 ; Decomposition by Acids, 4 ; by Alkalies, 5 ; by Salts, 6 ; Com- 
 bination with Salts, 5 ; Decomposition by Ferments . . . . , 6 
 
 Sulphur 79 
 
 Sulphurous Acid 38, 79 
 
 Superheat Clarification 29 
 
 Syrup Clarification, 45 ; Elimination 45 
 
 Table for the proper Adjusting of the Bagasse Turner for Three EoUer Mills .... 80 
 
 Table showing the Solubility of Sucrose in Water 81 
 
 Table showing the Specific Gravity of Milk of Lime 82 
 
 Table showing the Specific Gravity of Soda Solutions 83 
 
 Table for the Specific Gravity of Carbonate of Soda 83 
 
 Table for the Specific Gravity of Phosphoric Acid 84 
 
INDEX. V. 
 
 FAOE 
 
 Table showing the Relation between Degrees Celsius and Fahrenheit 85 
 
 Tannic Acid 10 
 
 Tartaric Acid 9 
 
 Temperature of Carbonatation, 35 ; of First Masse-cuitea, 49 ; of After-Products 
 
 Masse-cuites 66 
 
 Tempering, on Defecation, 26 ; on Carbonatation , 33 
 
 Trash Turner 15, 80 
 
 Triple EfEet 43 
 
 Yacuoles, Juice in 13 
 
 Vacuum Pan 47 
 
 Water, amount in First Masse-cuites 50 
 
 Water, in the Centrifugals, Covering with 59 
 
 Wax 11 
 
 Xanthine 1" 
 
 Xylan H 
 
 Yaryan Apparatus *5 
 
 Teast, Action on Sucrose, 6 ; on Dextrose 8 
 
■._?*- 
 
 
 ttr 
 
 ; ■'tt ^ 111