[Footnote 1: Royal Institution of Great Britain.]
[Footnote 2: _Comptes Rendus_ of the French Academy of Sciences.]
[Footnote 3: It is often desirable to make one of the apertures twice
the diameter of the rest; it causes a greater intensity to be given
to one image, and that facilitates the calculation of time, while it
furnishes points for the comparison of the movements of the lower limbs
with those of the arms.]
[Footnote 4: Ang. Guerout, in _La Lumiere Electrique_.]
[Footnote 5: Abbe Moigno, in his treatise on telegraphy, assigns the
date of 1838 to this publication; but Mr. Zetsche (_d.c._) gives it
as 1811. We shall consider the latter as the true date; for, in 1838,
there was no reason for publishing Soemmering's memoir, and especially
for proposing improvements in his apparatus.]
[Footnote 6: Abstract of a paper read before the New York Academy of
Sciences.]
[Footnote 7: Trans. Am. Med. Ass'n, 1880.]
[Footnote 8: In foetal syphilis it is assumed that the spermatozoa
may be the carriers of the disease; but no microscropist has yet
described a separate species of spermatozoon for such cases.]
[Footnote 9: "The Philosophy of Mystery," London, 1841; cited by
Hammond in his work on "Insanity."]
[Footnote 10: See articles by Dr. Hammond in this journal for 1865
and in the "Journal of Psychological Medicine" for 1869, also his
"Sleep and its Derangements," Philadelphia, 1872, and his "Treatise on
Insanity," New York, 1883.]
[Footnote 11: Yung, "Le sommeil normal et pathologique," Paris, 1883.]
[Footnote 12: "Leçons sur l'appareil vaso-moteur," t. ii., p. 154.]
[Footnote 13: "Principles of Psychology," vol. i., pp. 88, 89.]
[Footnote 14: "Les causes du sommeil," "Revue scientifique," t. xix.]
[Footnote 15: Yung, _op. cit._]
[Footnote 16: Magnetic iron and pyrites in basic rocks; tin stone in
granite and porphyry.]
[Footnote 17: Ancient authors report cases of this kind.]
[Footnote 18: The largest bronze statue of modern times is the
"Bavaria" in Munich, which is 20 meters high and weighs 80 tons. It
consists of 12 pieces and cost about a quarter of a million dollars.]
[Footnote 19: When a bronze is remelted six times the percentage of
tin is reduced to half the original (Dumas). The evaporation of the
metal can be shown by holding a cold plate on it while melted. Tin is
immediately deposited on it.]
[Footnote 20: They usually made a copper and zinc alloy, but it is
possible that they also understood the art of embedding the casting in
zinc ore (calamine) and heating strongly, whereby the surface of the
metal was "cemented" and colored.]
[Footnote 21: On examining a broken surface of an antique mirror, it
will be seen that only the outside is white. It is probable that the
finished mirror was embedded in some arsenical substance and heated,
which cemented and colored the surface.]
[Footnote 22: Uchatius makes his famous hard bronze by cooling and
hydraulic pressure. Bronzes with 8 to 12 per cent. of tin are most
benefited by this process. Bronzes with very little tin in them are but
little affected by chilling and hammering (Riche). Alloys that are hard
already, such as bronzes rich in tin and phosphorus, become too brittle
and useless by repeated hammering.]
[Footnote 23: When a cast sheet of inelastic bronze or brass is
hammered or rolled, it "feathers."]
[Footnote 24: The Romans preferred to put in some bronze that had been
repeatedly cast.]
[Footnote 25: One piece was scarcely scratched by feldspar, another
by quartz. The Greek and Roman weapons in the Berlin Museum were
tested as to hardness by Dr. Von Dechend at the suggestion of the
Director-General, Von Schone. All of them were scratched by fluorspar;
there were no hard bronzes among them. If the races of _classical_
antiquity were not acquainted with hard bronze, it is easy to see why
they soon began to use iron, in contrast with the Semitic-Hamitic
races.]
[Footnote 26: Excrements were also much used by the alchemists and
pharmacists of the middle ages.]
[Transcriber's Note: