A report of the computation of tables, to be used with the hydrometer recently adopted for use in the United States custom-houses / made under the superintendence of A.D. Bache, by R.S. McCulloh.

  • Alexander Dallas Bache
Date:
1851
Catalogue details

Licence: Public Domain Mark

Credit: A report of the computation of tables, to be used with the hydrometer recently adopted for use in the United States custom-houses / made under the superintendence of A.D. Bache, by R.S. McCulloh. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    r 9 [28] •eption of Jamaica spvits, the densities of all the alcoholic liquors of com- nerce are not appreciably affected by the flavoring substances they con- iin; or, in other words, that, for alcoholonietric purposes, we may con- ider spirituous liquors to be simple mixtures of alcohol and water. This act, though generally asserted and admitted, appears to have depended leretofore upon a few unpublished and isolated results, or to have been nnceded to authority rather than established by thorough investigations, t, therefore, demanded experimentsd confirmation, especially as it is ma- ; arial to the accuracy of the alcoholometric tables, which are based upon 1 he hypothesis that the density of a spirituous liquor depends only upon ae water and alcohol it contains, or that the effects of any impurities are aappreciable. At my request, Mr. Weightman, of the firm of Powers & Weightman, ccompiished manufacturing chemists of Philadelphia, undertook to pre- •are for me alcohol of the greatest possible degree of concentration. I igret to say, however, that he did not succeed in making it of the specific -ravity 0.793S at 60° Fahr., water being unity, the result obtained by fr. Drinkwater. (See page 488, Sen. Doc. No. 50, 30th Cong., 1st ses- 'on ) It was my purpose to have endeavored, by careful experiments, 1 determine the specific gravity of alcohol concentrated to a maximum, .ad by chemical reactions and analyses ascertained to be as pure as can I 3 made; but for this investigation my official duties at the mint did not ; .low me sufficient time. The subject, however, is one of scientific im- ■•Drrance only; for the question, what constitutes the true density of any •libstance, is one which can only be approximately determined; and it is, ■^erefore, more exact to assume an arbitrary standard, such as Tralles’ ■^3ohol,of the density 0.7939, at 60° Fahr., than to employ a natural one, ihich might be in error, however carefully sought. If ever the true den- :■ vy of pure alcohol should be more exactly determined, it cannot differ . i>m that of Tralles by an amount which can be practically appreciated ■ commercial purposes; and, for scientific ends, it will be easy, in any -stance, to apply a small and suitable correction. :: The hydrometer to be used with the manual of tables is the thermo- loholometer, (a combination of the alcoholometer of Tralles with a r.i ihrenheit’s thermometer,) made by J. G. Greiner, jr., of Berlin—a speci- i. in of which is herewith sent to you. One hundred of these instruments :•! ve been imported from Germany. They are of exquisite workmanship n every respect; for the careful and thorough verification to which I have bjected them, (see chapter III of this report,) has shown them to be as '1 act as they are beautiful, 'd’hese instruments are now ready for de- r cry to the custom-house officers, together with the manuals, which I iv‘ Id subject to your order. The opinion which I formerly expressed, that glass is the only proper ■H terial for the manufacture of hydrometers, I may here repeat; the dif- enee being that they are broken by blows which indent and destroy ; accuracy of those of metal. The latter corrode, and cannot be kept ' 1 an; they are also far more expensive. On the score of economy alone, government should employ glass instruments. The hydrometers iin- 'r ted from Berlin cost six dollars each; and for Dycas’s hydrometer de by Fisher, the price has been, 1 believe, about twenty five dollars! ,ptiT the same instrument made in Liverpool by the patentee, the cost in s country has been fifty dollars. A single careless blow will destroy