SUGAR.— Strength or Liquors. 893
Liquor No. 1 is then poured into the tube, * andallowed to soak through the sugar slowly till it runsaway into the vacuum bottle colourless, or verynearly so. Then this liquor is just sucked out, andthe sugar left is rinsed successively by No. 2, No. 3,and finally by absolute alcohol. By sucking drywarm air through the tube the sugar can be speedilydried, and then weighed; but it is much quickerand better to transfer it to a 100 c.c. flask, dissolve,clarify, and “ polarize ” it. The results are veryconstant if no great variations of temperature haveoccurred since the liquors were saturated, and if thesugar under examination has been well air-dried forsome time before being washed. Though constantand reliable for good “beet” sugars and nearly all“ canes,” the results are altogether fallacious whenobtained from low beets (second and third runnings),because in these, which have been crystallized veryslowly, many of the salts are in combination withsugar in the form of crystallized compounds whichare not dissolved by the liquors, but which, whendissolved in water in the process of refining, cannotbe recrystallized in the time at command. More-over, the method assumes that all the sugar whichis in solution in the adhering molasses will pass intothe final residue of molasses, or that all the impuri-ties which interfere with the crystallization of thesugar will remain intact and undiminished, althoughit is certain that some of the worst of them (such asthe gummy bodies) will be removed from the solutionby the animal charcoal or other purifying substancesor processes.
Stammer, a very careful chemist and practicalsugar maker, states that according to his experiencethe actual out-turn in refining beet sugar differs butvery little from that calculated on the French system.Weinrich, Weiler, and Schultz —the latter fromthe experimental work of years in a refinery—cometo the conclusion that in practice the out-turn inrefined sugar equals the total sugar, less the totalsolid impurities (soluble) X 2. This applies tobeet sugars only.
Strength of Liquors .—Among the constantly recur-ring operations of a sugar factory or refinery,none comes round so often as the making a roughdetermination of the strength of syrups, &c., byhelp of some sort of specific - gravity float. Thealmost universally used Beaume’s float is graduatedthus:—The point to which it sinks in pure water ismarked, and then that in which it stands whenimmersed in a solution of 15 parts of pure, dry,common salt in 85 parts of water. The spacebetween is divided into 15 equal parts or degrees,and the scale so made continued on to thirty ormore similar and equal divisions. This scale isthus purely arbitrary, and needs the use of a table
* ScHEUU.Eii himself first pours absolute alcohol into thesugar, and allows it to stand some time to take up the waterof the molasses, to prevent the dilution of solution No. 1 tosuch an extent that it could dissolve any of the crystallizedsugar. It is, however, in every way better to suck dry, andif possible, warm air through the tube and its contents tillthe greater part of the water is removed. .In this way oneavoids the danger of precipitating more sugar from the mo-lasses (by the alcohol), and so obtaining results too high.
to reduce its readings to percentages of sugar—orrather of apparent sugar — since very few sugarliquors so tested consist of pure sugar and water,and the other soluble solids likewise raise the specificgravity. In the absence of a table it is sufficient tomultiply the degree Beaume by X'8, in order to findvery nearly the apparent sugar contents.
Degree,
Heamui.
Per cent,.apparent.Sugar byWeight.
SpecificGravity ofthe Solution.
Degree,
Beaume.
Per cent,apparent.Sugar byWeight.
SpecificGravity ofthe Solution.
0
0-00
1-0000
26
47-73
1-2203
0-5
0-90
•0035
26-5
48-68
•2255
1
1-80
•0070
27
49-63
•2308
1'5
2-69
•0105
27-5
50-59
•2361
2
3-59
*0141
28
51-55
•2414
2-5
4-49
• OL 77
28-5
52-51
2468
3
5-39
•0213
29
53-47
•2522
3*5
6*29
*0249
29-5
54-44
-2576
4
7-19
*0286
30
55 47
•2632
4‘5
8-09
*0323
30-5
56-37
•2687
5
9*00
•0360
31
57-34
•2743
5-5
9-90
■0397
31-5
58*32
•2800
6
10-80
*0435
32
59-29
*2857
6-5
11-70
*0473
32-5
60-27
•2915
7
12-61
•0511
33
61-25
•2973
7-5
13-51
•0549
33-5
62-23
•3032
8
14-42
■0588
34
63-22
■3091
8'5
15-32
•0627
34-5
64*21
■ 315 L
9
16'23
•0667
35
65-20
1-3211
9-5
17*14
•0706
35-5
66-19
•3272
10
18-05
•0746
36
67-19
•3333
10-5
18-96
•0787
36*5
68-19
■3395
11
19-87
■0827
37
69-19
■3458
11-5
20*78
•0868
37-5
70-20
•3521
12
21-69
•0900
38
71‘20
•3585
12*5
22-60
•0951
38-5
72-22
•3649
13
23*52
•0992
39
73*23
•3714
13-5
24'43
•1034
39-5
74-25
•3780
14
25-35
■1077
40
75*27
■3846
14-5
26-27
•1120
40-5
76-29
•3913
15
27-19
•1163
41
77*32
■3981
15‘5
28*10
•1206
41-5
78-35
•4049
16
29-03
•1250
42
79-39
•4118
16-5
29-95
•1294
42-5
80-43
•4187
17
30-87
•1339
43
81-47
•4267
17-5
31-79
•1383
43-5
82-51
•4328
18
32*72
•1429
44
83 56
•4400
18*5
33-65
■1474
44-5
84-62
•4472
19
34*58
1520
45
85-68
•4545
19-5
35*50
•1566
45*5
86-74
•4619
20
36*44
•1613
46
87-81
•4694
20*5
37-37
•1660
46-5
88-88
•4769
21
38-30
•1707
47
89-96
■4845
21-5
39-24
•1755
47-5
91-03
•4922
22
40-17
•1803
48
92-12
•5000
22*5
41*11
•1852
48-5
93-21
•5079
23
42-05
•1901
49
94-30
•5158
23-5
42-99
•1950
49-5
95.40
•5238
24
43-94
•2000
50
96-51
•5319
24'5
44-88
•2050
50-5
97-62
■5401
25
45-83
•2101
51
98-73
•5184
25*5
46-78
•2152
51-5
99-85
•5568
A very convenient and instructive method ofcomparing one juice or one syrup with another is todetermine in each case, first, the specific gravity(and hence the quantity of soluble solids, supposingthey all had the same density as sugar in solution),and then the real quantity of sugar present. Thepercentage of sugar contained in 100 parts apparentsolids may be called the “ apparent purity coeffi-cient ” of that juice or syrup, and serves better thanany other number as a means of comparison of onewith another. Of course the real “total solids" maybe determined, and the real purity coefficients found;