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126
Dec 24th 1844
Experiments made in Phid on tenacity of water.
My Frend, Mr. Eckfelt of the United States Mint, kindly offered to assist me in making some experiments on the tenacity of water.  Two discs of copper were prepared under the superintendance of Mr. E.  These were circular and flat; the one two inches in diameter, and the other one inch.  They were experimented with in succession by being suspended and [[word crossed out]] cone [[/word crossed out]] horizontally from one end of one of the delicate balances of the mint, and counter poised by a weight in the opposite scale.  The water employed was distilled, and the room was kept [[word crossed out]] of [[/word crossed out]] at the temperature of 65°.  The following were the results:
                                          grams
Pure distilled water, one inch disc       41.52
         "      "     two inch  "        165.30
These are deduced from the means of a number of experiments.
Saturated solution of Neusor soap with the one inch disc                                 grams
                                          25.46
Capillary Weight measure
The specific gravity of the water saturated with soap, was not increased more than 1/1000 or one 1/10 of a percent.
[[image]] Cotton placed on a ring 3 inches in diameter, broke with a weight 8 grams. In another exp. the weight of cotton was 11 gms.
Each disc was elevated as follows: The one inch about 3 divisions of a scale .065 of an inch.  The two inch about 1 1/2 of the same. The water which adhered to the disc after separation in each case was 3/4th of a grain. [[end page]]
[[start page]]127
Dec 24 1844 | Tenacity of water
[image] When a soap film was placed across the mouth of a glass funnel, it was not at any point in a state of equilibrium, but moved up towards the apex of the curve.  The cause of this is easily understood, the attraction on account of the greater inclination of the film on one side, rather than on the other, caused the motion. [[line across page]]
Called the same morning at the Cornelius', the lamp manufacturers, was shown the experiment which he had instituted at my request some months before, namely, the sinking [[word crossed out]] of silver into copper.  I had asked him on a former visit whether he ever found the silver from plated copper to disappear in heating it.  The answer was "yes, it evaporates." does it not, said I, sink into the copper. He made the experiment and found the result which I had anticipated. To remove the copper, he first used a galvanic battery, the copper being placed on the pole which would cause solution, but afterwards, he found that the silvered surface could be restored by dipping the plate into the soldering liquid, mureate of zinc. He showed me a piece of plated copper uniformly covered with silver, which he heated at one end over the forge until the silver disappeared, and the surface exhibited the appearance of copper, this was then dipped into the zinc liquid and the silver again appeared.  Mr. C. informed me that the [[word crossed out]] knowledge of this process would a few years ago have saved him many hundred dollars in the course of a year.  Articles of plated metal [[word crossed out]] were often spoiled by the disappearance of the silver as he supposed by evaporization.  The fact is not now of as much consequence, since the plating process is carried on in his establishment by means of the galvenic process. [[end of page]]