with which patients and
others volunteer the statement that they can breathe deeper, confirms
the opinion that the depth of respiration is increased; more bulk of
air being taken in to give to the lungs an equivalent amount of
oxygen, greater depth of breathing must needs follow. The increased
chest development and the necessarily greater use of the respiratory
muscles makes it tolerably certain that they are strengthened.

"_Appetite and Assimilation._--'In most cases there is a transient or
permanent increase of appetite and assimilation of nourishment.'

"There is certainly direct evidence of the former to be found in
Colorado, but as change of scene and air produce it almost
everywhere, where the general conditions are not unfavorable to
health, and notably so at the seashore, and also on shipboard when
the depressing effects of seasickness are absent or passed away, it
is doubtful how far this may be taken as a special effect of
altitude, except through the increased oxygenation produced by both
sea and mountain air. It would appear that in those with whom
Colorado agrees there is a greater consumption of meat, a good
appetite, and probably an increased one. That there is also an
increased assimilation of nourishment may be inferred from an
increased appetite without dyspepsia, in fact the improvement that
usually takes place in dyspeptic conditions, during residence in
Colorado, is a good evidence of increased or, at least, more perfect
assimilation.

"_Nourishment._--'From this follows an improved formation of blood
and nourishment of the organs.' The general vigour of the circulation
with the ruddier colour, which has been dwelt upon, would show that
the improved quality of the blood must be due not only to the causes
previously pointed out, more oxygen absorbed, etc., but also to the
more perfect conversion of food into blood; all this will likewise
apply to the better nourishment of the organs which can be inferred
from similar grounds.

"_Sleep_ 'is usually improved.' This appears to be the case in
Colorado in healthy persons, and in those invalids with whom the
climate agrees; during their first few weeks of residence there is
more or less tendency to nap, though between times they may be
particularly wide awake. Later it would seem that less sleep is
needed to sustain health, though it is especially profound. As
regards the individual, the temperament probably largely influences
this matter. The torp