1847.] United States Coinage. 73 



areas. The silver crystalizes as it is deposited upon the plan- 

 chet; and afterwards, when it is struck with the die, some of the 

 crystalline surface will remain, which may be distinctly seen by 

 aid of the microscope. This is the lact with the Palmyra emis- 

 sion, or the Williams counterfeit; which, in other respects, are 

 quite good imitations of Mexican dollars. 



Inspection of the workmanship is also important. Straggling 

 letters, an eagle with an open mouth, or some defect in this par- 

 ticular, is so common that inspection alone will lead to suspicion. 

 So perfect are our coins at present, that it has become an impor- 

 tant safeguard to the metallic currency. 



Dimensions. — Comparison with a true piece may often detect 

 an impostor. It is, however, more likely to be too thick than too 

 large; as it is more difficult to adjust the latter than the former. 



2. Smell. Copper and its alloy with silver and German sil- 

 ver, when warmed by friction, gives off an odor; whereas, genu- 

 ine silver coin does not. It is a test of limited application. 



. 3. Hearing, or sound. This test is the one which is too much 

 relied upon, though it is not without its value. German silver 

 has a sharper ring than the true coin. Sometimes a counterfeit, 

 ■ especially the older counterfeit dollars, which were usually a 

 plated pewter, gave a very dull, flat sound. The test is performed 

 by balancing the suspected piece upon the finger and gently 

 striking it with another. But a genuine coin may, for certain 

 reasons, give a suspicious sound; and hence, it is valuable only 

 for raising suspicions, which shall lead to a more perfect test. 



4. Feeling. The touch is often tried upon coin as a test of 

 genuineness. Thus, it is well known that German silver, pewter 

 and tin feel smooth and greasy; and that real well washed silver 

 does not. Practice, undoubtedly, will so far improve the percep- 

 tibility of this sense that it may be useful. Still, this and the 

 foregoing, except the first, are comparatively unimportant. 



Mechanical tests. — Among these, we may enumerate filing, 

 cutting and weighing. Both filing and cutting have two objects 

 in view; the determination of the metal beneath the surface, and 

 the hardness of the piece. As we have before stated, hardness is 

 an important quality; and it is the same for all simple bodies: 

 that is, each substance has its own hardness; and this is deter- 

 mined by the resistance which is overcome in the mechanical 

 process which may be resorted to to impress or remove a part of 

 it. It requires experience, and at the same time a comparison of 

 it with the hardness of the genuine coin. In filing, a deep, nar- 

 row cut is made, sufliciently deep and wide to disclose the inte- 

 rior of the metal. 



The most important of the mechanical tests, however, is weigh- 

 ing, or counterpoising it with a piece of the same denomination. 



