24
ALCOHOL.
these effects being greatest with 54 per cent, of alcohol and 46 of water, and thence decreasing with a greater proportion of water. For alcohol which contains 90 per cent,of water this condensation amounts to 1-94 per cent, of the volume: for 80 per cent.,2-87; for 70 per cent., 3-44; for to per cent., 3-73 ; for 40 per cent., 3-44; for 30 percent. 2-72; for 20 per cent., 1-72; for 10 per cent., 0-72. Hence, to estimate thequantity of alcohol in any spirit it is necessary that the specific gravity be ascertainedfor each determinate proportion of alcohol and water that are mixed together. Whenthis is done, we may, by means of an areometer constructed for liquids lighter thanwater, determine the strength of the spirit, either by a scale of specific gravities or by anarbitrary graduation corresponding to certain commercial objects, and thus we may de-termine the per centage of alcohol in whiskey or brandy of any strength or purity. Anareometer intended for this use has been called an alcoholmeter, in particular when thescale of it is so graduated that, instead of the specific gravity, it indicates immediatelythe per centage of anhydrous alcohol in a given weight or volume of the liquid. Thescale graduated according to the per centage of pure alcohol by weight, constitutes thealcoholmeter of Richter; and that by the per centage in volume, the alcoholmeter ofTralles ancl Gay Lussac .
As liquors are sold in general by the measure, not by the weight, it is convenient,therefore, to know the alcoholic content of the mixtures in the per centage by volume.Tralles has constructed new tables upon the principles of those of Gilpin, in which theproportion is given by volume, and anhydrous alcohol is assumed for the basis; which,at 60° Fahr., has a specific gravity of 0-7939 compared with water at its maximumdensitj r , or a specific gravity of 0-7946 compared with water of the temperature of 60°Fahr. Gilpin's alcohol of 0-825 contains 92-6 percent, by volume of anhydrous alcohol.
The following table exhibits the per centage of anhydrous alcohol by volume, at atemperature of 60° Fahr., in correspondence with the specific gravities of the spirits,water being considered at 60° Fahr. to have a specific gravity of 0-9991.
Alcoholmetrical Table of Tralles.
Alcohol in 100measures ofspirit.
Specific gravityat 60° Fahr.
Difference ofthe sp. gr.
Alcohol in 100measures ofspirit.
Specific gravityat 00° Fahr.
Difference ofthe sp. gr.
0
9991
51
9315
20
i ■
9976
15
52
9295
20
2
9961
15
53
9275
20
3
9947
14
54
9254
21
.4
9933
14
55
9234
20
5
9919
14
56
9213
21
6
9906
13
57
9192
21
7
9893
13
58
9170
22
8
9881
12
59
9148
22
9
9869
12
60
9126
22
10
9857
12
61
9104
22
11
9845
12
62
9082
22
12
9834
11
63
9059
23
13
9823
11
64
9036
23
14
9812
11
65
9013
23
15
9802
10
66
8989
24
16
9791
11
67
8965
24
17
9781
10
68
8941
24
18
9771
10
69
8917
24
19
9761
10
70
8892
25
20
9751
10
71
8867
25
21
9741
10
72
8842
25
22
9731
10
73
8817
25
23
9720
11
74
8791
26
24
9710
10
75
8765
26
25
9700
10
76
8739
26
26
9689
11
77
8712
27
27
9679
10
78
8685
27
28
9668
11
79
8658
27
29
9657
11
80
8631
27
30
9646
11
81
8603
28
31
9634
12
82
8575
28
32
9622
12
83
8547
22
33
9609
13
84
8518 ’
29