336 Memorias de la Sociedad Científica 
which requires a variable period, according to the altitude and 
the individual, the respirations are not nearly so much increased 
in frequence during rest, but the depth of breathing becomes 
habitu»lly greater. This is shown by the large spirometrical 
records of these who live at great elevations and the increased 
size of the chest in children and in resident adults. This is fur- 
ther shown by the necessity of the climatic change to supply 
the usual, if not augmented, demand for oxygen, Which is to 
meet an increased combustion or change of tissues. The inerea- 
sed exhalation of carbonic acid is due to the chest expan- 
sion. (2)” 
“And lower air temperature, as well as the increased chest 
measúrements in those invalids who are not so far advanced 
in disease but that the affected lung tissue can be returned to 
use (an effect noted in the writer's cases, as well as in those of 
C. T. Williams, Weber, and others), are in perfect accord with 
the habitual use of more air for all the purposes of living in 
high altitudes.” 
“The heart and lungs, having a reciprocal relation to each 
other, are both proportionalety more active. In imperfect res- 
piratory states, or incipient phthisis, the impeded circulation 
feels the “boom,” so to speak, especially in those portions of 
the body which were the least active before, namely, in the 
lung periphery and capillary system generally. The results is 
a more perfect circulation of the blood and oxygenation of 
healthy tisues 'as wel as of carbonaceous and effete materials. 
The supply and waste are more completely attended to and the 
sewer work of the respiratory system, especially, is a cleaner 
and more finished process. Not only this much, but there is a 
change in the relative density of the air in the lungs, due to 
this increased actvity and to the fact that the air breathed is 
rarefied. There is a pneumatic differentiation as the inventors 
call it, going on all the time and this is better than any spas- 
g odic or artificial effect.” 
