CLIMATE IN THE CURE OF CONSUMPTION. 427 
Clear, Fair, and Cloudy Days.— We now come to the consideration of 
our last general point, that is, to an investigation of the number of clear, fair, 
and cloudy days; or, in other words, to a consideration of the amount of sun- 
shine. 
As to the direct effect upon health produced by light and sunshine, we are 
still in ignorance. Whether the blood is made to course more rapidly, and the 
nerves transmit impulses more readily, under the influence of the solar ray is not 
iknown. It is well known that the actinic rays have a powerful chemical effect 
upon vegetation ; but whether or not they have a like influence upon the human 
economy is unknown. 
Without attempting to refine, there are certain broad and positive effects in 
the cure of phthisis attributable to sunshine. The experience of the profession is 
fittingly expressed by the words of Dr. Austin Flint: "I would rank exercise 
and out-of-door life far above any known remedies for the cure of the disease." 
In the table which we present, and which is a mean of daily observations for 
a period of five years, a cloudy day is one in which the heavens are from seven- 
tenths to entirely obscured by clouds; a fair day is one in which the heavens are 
from four to seven-tenths clouded ; all else are classed as clear days. From this 
it will be seen, that for our purposes clear and fair days may be classed as one, 
and may be put into juxtaposition with the cloudy days. Consulting these tables, 
it will be seen, that in Denver the mean number of cloudy days in a year is only 
one-half of what it is in either Augusta or Jacksonville, that it is less than a half 
of what it is in St. Paul, and that it is slightly less than what it is in Los Angeles. 
To put this fact in another way, it is seen, that in Denver there is only about 
one-eighth of the entire year when an invalid would be kept in "the house on 
account of the weather ; in Jacksonville and Augusta he would be confined to 
the house, for the same reason, one quarter of the year; in St. Paul he would be 
kept in-doors between a third and a quarter of the time ; while in Boston he would 
have to be housed a good third of the time. 
Admitting, then, the force of Dr. Flint's statement, our tables show that 
there is no place in this whole country, where it is possible for the invalid to 
enjoy so much fresh air and sunshine, as in the Rocky Mountains. For three 
hundred and twenty days out of every three hundred and sixty -five it is possible 
to roam at large, and to breathe in health. 
We feel, that, so far, our tables have shown that the Rocky Mountains 
furnish climatic conditions of elevation, humidity, precipitation, temperature, 
winds, and sunshine, which recommend them as a resort for phthisical invalids 
superior to anything to be found in this country. 
Observations by Seasons. — Having arrived at these general conclusions, 
the writer wishes to call attention very briefly to their accuracy and importance 
as applied to the different seasons of the year. He wishes to lay stress upon the 
evidence, which goes to show that Colorado and New Mexico furnish favorable 
resorts for phthisical invalids during the winter and spring, — the very seasons 
.that are most trying in the east, the seasons that they are obliged to avoid, and 
