328 MEMORIAL OF JOSEPH HENRY. 



Hydrometric Experiment. A novel project for the rectification 

 of spirits by the simple process of static separation of the alcohol 

 and water by the stress of their specific gravities when exposed in 

 long columns, produced in 1854 a considerable sensation. It was 

 alleged in various publications by those interested in the new enter- 

 prise, that the coercitive compression exerted by the water in a 

 long hydrostatic column greatly accelerated the displacement and 

 separation induced by gravitation, and that only a few hours were 

 necessary to complete the process, if the depth of the liquid were 

 sufficiently great.* 



A patent was obtained : affidavits and samples fully attested the 

 wonderful efficiency of the process; and only the co-operation of 

 confiding capitalists was required, to realize fabulous profits, and 

 effect a manufacturing and commercial revolution. 



Simply in the interests of truth, Henry undertook the careful 

 investigation of this surprising pretension. One of the towers of 

 the Smithsonian Building supplied a convenient well for the experi- 

 ment, easily accessible throughout its height. "A series of stout 

 iron tubes of about an inch and a half internal diameter formed 

 the column; the total length of which was one hundred and six 

 feet. Four stop-cocks were provided ; one at the bottom, one about 

 four feet from the top, and the other two to the intermediate space 

 equally divided or nearly so." Very careful hydrometer and ther- 

 mometer registers were made at increasing intervals of time, the 

 last being that of nearly half a year: a portion of the reserved 

 liquor being simultaneously tested. The result stated, is: "There 

 is not the slightest indication of any difference of density between 

 the original liquor and that from the top or bottom of the column, 

 after the lapse of hours, days, weeks, or months. The fluid at the 

 bottom of the tube it must be remembered was for five months 

 exposed to the pressure of a column of fluid at least one hundred 

 feet high." f 



* An incidental remark in Gmelin's "Handbook of Chemistry" seemed to give 

 some color of plausibility to the scheme. "Brandy kept in casks is said to con- 

 tain a greater proportion of spirit in the upper, and of water in the lower part." 

 Gmelin's Handbook, Translated by Henry Watts, London, 1841, part i. sect. 4, 

 vol. i. p. 112. 



t Proceed. Am. Assoc. Providence, Aug. 1855, pp. 142, 143. 



