His own poems and compositions were shown
to him, but he could not he persuaded that they were his production.
Afterwards, however, he began once more to compose verses; which had so
striking a resemblance to his former writings that he at length became
convinced of his being the author of them.--_From the Doctor._
* * * * *
READING COINS IN THE DARK.
(_From Sir David Brewster's Letters on Natural Magic_.)
Among the numerous experiments with which science astonishes and
sometimes even strikes terror into the ignorant, there is none more
calculated to produce this effect than that of displaying to the eye
in absolute darkness the legend or inscription upon a coin. To do this,
take a silver coin, (I have always used an old one,) and after polishing
the surface as much as possible, make the parts of it which are raised
rough by the action of an acid, the parts not raised, or those which
are to be rendered darkest, retaining their polish. If the coin thus
prepared is placed upon a mass of red hot iron, and removed into a dark
room, the inscription upon it will become less luminous than the rest,
so that it may be distinctly read by the spectator.
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