1847.] United States Coinage. 75 



weight of the piece to the true standard, it will be too large, and 

 may be discovered by measurement, and its spuriousness deter- 

 mined by its specific gravity, which will of course be too low. 

 These measures, too, have the advantage of not injuring or de- 

 facing a piece; and none are superior to these in determining the 

 fact of spuriousness or genuineness, though they do not determine 

 composition. For, however they might be suspicious in sound, 

 feel or workmanship, if the size, weight and specific gravity are 

 right, then the coin must be genuine. We might, perhaps, ex- 

 cept an alloy of gold and platina; but we have little to fear, as 

 platina is too rare and expensive to be employed in counterfeit- 

 ing when profit is an object. 



The American eagle counterfeited Avith a gold surface upon 

 silver, will weigh about 179 grains, and have a specific gravity of 

 10.3 to 10.7. The workmanship of such a piece will, of course, 

 be genuine, and its value wall be 50 cents. 



The doubloon of Colombia is counterfeited by gilding in the 

 same way as the old half American dollar piece. The workman- 

 ship will be genuine, but its specific gravity be only 10.3, as 

 above; and the same may be stated of all the spurious gold coin 

 upon a foundation of silver. 



The German silver half dollar pieces of the Watertown emis- 

 sion have a specific gravity of 8.] 9. They contain no silver, and 

 have no value. They are all too light; their actual weight, as 

 •well as specific gravity, being uniformly too low. 



Chemical character. — The relation which bodies sustain to each 

 other are always the same. Thus, the action of acids upon met- 

 als is uniformly one action under the same circumstances. The 

 colors of the solutions produced also are the same for a given 

 metal. Hence, if a coin is subjected to the action of nitric acid 

 it will behave uniformly with it; and its solution, if soluble, will 

 be of a uniform color. For the determination of the fact of 

 genuineness, then, we may rely upon the results of the action of 

 an acid upon it. Gold is unaffected in any one acid; but mix 

 nitric and muriatic together and it dissolves. Silver is soluble in 

 nitric acid alone; and the solution, when the silver is pure, is color- 

 less: but it stains the fingers or skin a blackish brown and cannot be 

 removed by w- ashing. If muriatic acid is added to such a solu- 

 tion it precipitates a gray powder, which becomes purple in sun 

 light or if organic matter is present. Silver coin contains cop- 

 per; and in consequence of the presence of copper the nitric acid 

 solution w'ill be green or greenish. The presence of silver is very 

 well determined by the daik stain upon the skin. The counter- 

 feit coin, if galvanized or plated with silver, will give for an in- 

 stant the same phenomena as the true, especially if new. A 

 darkish stain is first produced, which is formed by the action ot 



