January of 1920 came, and the river was frozen over. The flowing oxygen
was solid enough for men and horses to walk on. There they went in
beaten paths, warm water trudging along on cold! Jean had always been
amazed by such miracles, but their potency was doubled for her now, and
they kept her from breaking her heart.
Twice a week she and the dog tramped up the ice to the post-office,
always with the hope of not hearing from Marvin. Any letter from him
would mean that he had found a new girl. She ought to be hoping for such
a letter, but somehow her wicked heart declined to hope.
In her little laboratory she was perfectly free to risk her neck with
any experiment she chose. And considering that she had got the oxygen
from potassium chlorate, and that Horatio had barely missed passing out
by chlorine before he met his death by other forces, she found herself
wishing to see chlorine.
She read that it was usually a green gas, though it could be liquefied
and stored in steel tanks. She read that it combines with sodium to make
table-salt, though how a green gas could come to look so sparkling white
she did not understand. At first she thought she would coax it out of
salt, but having no electric battery she had to abandon that plan.
It was like fluorine and bromine, curious things of which she knew
nothing. It was also like iodine, with which people paint themselves on
the slightest provocation, though she suspected that soap and water will
ordinarily do as well. It was furthermore related in some mysterious way
to a heavy metal called manganese. She had not the faintest suspicion
that manganese conceals twenty-five charges of electricity, or that its
two undiscovered relatives conceal forty-three and seventy-five
respectively. But her book gave her to understand that chlorine can
easily be extracted from manganese chloride.
So she asked Ojeeg, who was now become so respectable that he was
carrying the mail, to bring her from the Soo a little manganese dioxide.
She wrote the magical words for him on a piece of birch bark, and next
time he not only brought the stuff to her in the clearing, but stood by
and watched her mix it with hydrochloric acid, heat it, and collect the
chlorine in a bottle.
They sniffed it and understood perfectly why it choked soldiers to
death. And long after Ojeeg left her, she stood pondering that greenish
yellow mist through its glass prison. It seemed incredible that human
beings would deliberately roll that death along the ground to fill the
nostrils of other human beings. But it had been done, and when the
madness again seized on men it would be done again. But there in her
silent retreat among life-giving wintry airs she determined that no son
of hers should ever be compelled to breathe chlorine.