of a
discovery. An early experimenter was at first "delighted with the white,
waxy substance that glowed so charmingly in the dark of his laboratory,"
but later wrote, "I am not making it any more for much harm may come of
it."

Robert Boyle wrote in 1680 of phosphorus, "It shone so briskly and lookt
so oddly that the sight was extreamly pleasing, having in it a mixture
of strangeness, beauty and frightfulness."

These words describe almost exactly the impressions of eye witnesses of
the first atom bomb test at Alamagordo, New Mexico, July 16, 1945.

For the next two and three-quarters centuries the chemists had much fun
and some fame discovering new elements. Frequently there was a long
interval between discovery and recognition. Thus Scheele made chlorine
in 1774 by the action of "black manganese" (manganese dioxide) on
concentrated muriatic acid (hydrochloric acid), but it was not
recognized as an element till the work of Davy in 1810.

Occasionally the development of a new technique would lead to the "easy"
discovery of a whole group of new elements. Thus Davy, starting in 1807,
applied the method of electrolysis, using a development of Volta's pile
as a source of current; in a short time he discovered aluminum, barium,
boron, calcium, magnesium, potassium, sodium, and strontium.

The invention of the spectroscope by Bunsen and Kirchhoff in 1859
provided a new tool which could establish the purity of substances
already known and lead to the discovery of others. Thus, helium was
discovered in the sun's spectrum by Jansen and isolated from uranite by
Ramsay in 1895.

The discovery of radioactivity by Becquerel in 1896 (touched off by
Roentgen's discovery of x rays the year before) gave an even more
sensitive method of detecting the presence or absence of certain kinds
of matter. It is well known that Pierre and Marie Curie used this
new-found radioactivity to identify the new elements polonium and
radium. Compounds of these new elements were obtained by patient
fractional recrystallization of their salts.

The "explanation" of radioactivity led to the discovery of isotopes by
Rutherford and Soddy in 1914, and with this discovery a revision of our
idea of elements became necessary. Since Boyle, it had been assumed that
all atoms of the individual elements were identical and unlike any
others, and could not be changed into anything simpler. Now it became
evident that the atoms of radioactive elements were const