d to spring,--"I was right," said the
great physician; "this is reason suspended, not reason lost. Your wife
will recover; but--"

"But what?"

"Give me your arm as I walk homeward, and I will tell you the conclusion
to which I have come."

I rose, the old man leaned on me, and we went down the valley along the
craggy ridges of the winding creek. The woodland on the opposite bank
was vocal with the chirp and croak and chatter of Australian birds,--all
mirthful, all songless, save that sweetest of warblers, which some early
irreverent emigrant degraded to the name of magpie, but whose note is
sweeter than the nightingale's, and trills through the lucent air with
a distinct ecstatic melody of joy that dominates all the discords, so
ravishing the sense, that, while it sings, the ear scarcely heeds the
scream of the parrots.

(1) Creek is the name given by Australian colonists to precarious water
Courses and tributary streams.

CHAPTER LXXI.

"You may remember," said Julius Faber, "Sir Humphry Davy's eloquent
description of the effect produced on him by the inhalation of nitrous
oxide. He states that he began to lose the perception of external
things; trains of vivid visible images rapidly passed through his mind,
and were connected with words in such a manner as to produce perceptions
perfectly novel. 'I existed,' he said, 'in a world of newly-connected
and newly-modified ideas.' When he recovered, he exclaimed: 'Nothing
exists but thoughts; the universe is composed of impressions, ideas,
pleasures, and pains!'

"Now observe, that thus a cultivator of positive science, endowed with
one of the healthiest of human brains, is, by the inhalation of a gas,
abstracted from all external life,--enters into a new world, which
consists of images he himself creates and animates so vividly that, on
waking, he resolves the universe itself into thoughts."

"Well," said I, "but what inference do you draw from that voluntary
experiment, applicable to the malady of which you bid me hope the cure?"

"Simply this: that the effect produced on a healthful brain by the
nitrous oxide may be produced also by moral causes operating on the
blood, or on the nerves. There is a degree of mental excitement in which
ideas are more vivid than sensations, and then the world of external
things gives way to the world within the brain.(1) But this, though a
suspension of that reason which comprehends accuracy of judgment, is
no more a perma