Method of detecting the Presence of Lead in Spiritous Liquors
The presence of lead may be detected in spiritous liquors, as stated on pages 70 and 86. The cordial called shrub frequently exhibits vestiges of copper. This contamination, I have been informed, is accidental, and originates from the metallic vessels employed in the manufacture of the liquor.
Method of Ascertaining the Quantity of Alcohol in Different Kinds of Spiritous Liquors
The quantity of real alcohol in any spiritous liquors may readily be ascertained by simple distillation, which process separates the alcohol from the water and foreign matters contained in the liquor. Put any quantity of brandy, rum, or malt spirit diluted with about one-fourth its bulk of water, into a retort fitted to a capacious receiver, and distil with a gentle heat. The strongest spirit distils over first into the receiver, and the strength of the obtained products decreases, till at last it contains so much water as no longer to be inflammable by the approach of a lighted taper, when held in a spoon over a candle (see p. 160.) If the process be continued, the distilled product becomes milky, scarcely spiritous to the smell, and of an acidulous taste. The distilling operation may then be discontinued. If the first, fourth or third part of the distilled product has been set apart, it will be found a moderately strong alcohol, and the remainder one more diluted. If the whole distilled spirit be mixed with perfectly dry subcarbonate of potash, the alcohol will float at the top of the potash, as stated, p. 161; it will separate into two distinct fluids. If the decanted alcohol be redistilled carefully with a very gentle heat, over a small portion of dry quick lime, or muriate of lime, it will be obtained extremely pure, and of a specific gravity of about 825, at 60° of temperature. Its flavour will vary according to the kind of spiritous liquor from which it is obtained.
Table exhibiting the Per Centage of Alcohol (of 825 specific gravity) contained in various kinds of spiritous Liquors.101
| Proportion of | |
| Alcohol per Cent. | |
| by Measure. | |
| Brandy, Cogniac, average proportion of 4 samples | 52,75 |
| Ditto, Bourdeaux, ditto ditto | 54,50 |
| Ditto, Cette | 53,00 |
| Ditto, Naples, average of 3 samples | 53,25 |
| Ditto, Spanish average of 6 samples | 52,28 |
| Rum | 53,68 |
| Ditto, Leeward, average of 9 samples | 53,00 |
| Scotch Whiskey, average of 6 samples | 53,50 |
| Irish Ditto, average of 4 samples | 54,25 |
| Arrack, Batavia | 49,50 |
| Dutch Geneva | 52,25 |
| Gin (Hodges’s,102) 3 samples, procured from retail dealers | 48,25 |
| Ditto (Ditto,)102 procured from the manufacturer | 52,35 |
Footnotes
88 George III. c. xxviii. May 1818—“An Act for establishing the use of Sikes’s hydrometer in ascertaining the strength of spirit, instead of Clark’s hydrometer.”
89 Sixteen and a half per cent. proof, according to Sikes’s hydrometer.
90 30 Geo. III c. 37, § 31.
91 According to Clarke’s hydrometer.
92 Observations on Malted and Unmalted Corn, connected with Brewing and Distilling, p. 167; and Shannon on Brewing and Distilling, p. 232, 233.
93 Water.
94 This operation forms part of the business of the so-called brewers’ druggists. It forms the article in their Price Currents, called Spirit Flavour.
Wine lees are imported in this country for that purpose: they pay the same duty as foreign wines.
95 Observations on Malted and Unmalted Corn, connected with Brewing and Distilling, p. 167.
96 Apicius Redivivus, 2d edition, p. 480.
97 Clark’s hydrometer.
98 30 Geo. III. c. 37, § 6.
99 Shannon on Brewing and Distilling, p. 198.
100 Ibid. p. 199.
101 Repository of Arts, p. 350, Dec. 1819.
102 Own experiment.