ith promise." (_Letters_, II, 123.) The words _Pulvis et Umbra_ mean
literally "dust and shadow": the phrase, however, is quoted from
Horace "pulvis et umbra sumus"--_we are dust and ashes_. It forms the
text of one of Stevenson's familiar discourses on Death, like _Aes
Triplex_.

[Note 1: _Find them change with every climate_, etc. For some striking
illustrations of this, see Sudermann's drama, _Die Ehre_ (Honour).]

[Note 2: NH3 and H2O. The first is the chemical formula for ammonia:
the second, for water.]

[Note 3: _That way madness lies. King Lear_, III, 4, 21.]

[Note 4: _A pediculous malady ... locomotory_. Stevenson was fond of
strange words. "Pediculous" means covered with lice, lousy.]

[Note 5: _The heart of his mystery. Hamlet_, Act III, Sc. 2, "you
would pluck out the heart of my mystery." Mystery here means "secret,"
as in I. _Cor_. XIII, "Behold, I tell you a mystery."]

[Note 6: _The thought of duty_. Kant said, "Two things fill the mind
with ever new and increasing admiration and awe, the oftener and the
more steadily we reflect on them: _the starry heavens above and the
moral law within_." (Conclusion to the _Practical Reason_--_Kritik der
praktischen Vernunft_, 1788.)]

[Note 7: _Assiniboia ... Calumet_. Assinibioia is a district of
Canada, just west of Manitoba. _Calumet_ is the pipe of peace, used by
North American Indians when solemnizing treaties etc. Its stem is over
two feet long, heavily decorated with feathers etc.]

[Note 8: _Drowns her child in the sacred river_. The sacred river of
India is the Ganges; before British control, children were often
sacrificed there by drowning to appease the angry divinity.]

[Note 9: _The touch of pity_. "No beast so fierce but knows some touch
of pity." _Richard III_, Act I, Sc. 2, vs. 71. _This ennobled lemur_.
A lemur is a nocturnal animal, something like a monkey.]

[Note 10: _A new doctrine_. Evolution. Darwin's _Origin of Species_
was published in 1859. Many ardent Christians believe in its general
principles to-day; but at first it was bitterly attacked by orthodox
and conservative critics. A Princeton professor cried, "Darwinism is
Atheism!"]

[Note 11: _Cultus_. Stevenson liked this word. _The swarming ant_.
"The ants are a people not strong, yet they prepare their meat in the
summer."--_Proverbs_, XXX. 25. For a wonderful description of an ant
battle, see Thoreau's _Walden_.]

[Note 12: _Everest_. Mount Everest in the Himalayas, is the