208 
Relation of Moisture in Air 
[April, 
our midland country, from Minnesota southwardly, are the 
healthiest regions of the United States ; and where, together 
with the dry atmosphere, some uniformity of temperature 
exists, as in Mexico, — where the height above the level of 
the sea reduces the sensible heat of the air which is usually 
found in that latitude to a comfortable one, — there we have 
the acknowledged climate of utmost healthfulness. Going 
into more torrid lands, the dryness of the air alleviates the 
heat of the deserts of Arabia, and of Africa, of Peru, and 
Bolivia, where the temperature rises at times to iio° or even 
120° in the shade. I have the assertion of a friend that on 
a hot day, with the thermometer nearly ioo°, he has known 
the wind on the Arabian Desert to be searchingly cold, when 
everything was shrivelling up for want of moisture. My 
attention was called by Dr. j. S. Billings to the following 
extract of his Report on the Hygiene of the U.S. Army in 
3:875 : — “ Description of military posts, Fort Yuma, Cali- 
fornia. Reports of Asst. -Surgeons Lauderdale and Ross, 
U.S. A. After describing the locality of the post, near the 
junction of the Giler and Colorado Rivers, they say : — 
‘ The heat increases rapidly from the latter part of May, 
and in June, July, August, and September may be said to 
be intense. . . . During the months of April, May, and 
June no rain falls ; then, with the thermometer at 105°, the 
perspiration is scarcely seen upon the skin, and it becomes 
dry and hard, and the hair crispy, and furniture falls to 
pieces, . . . ink dries so rapidly upon the pen that it re- 
quires washing off every few minutes. ... A No, 2. Faber’s 
pencil leaves no more trace on paper than a piece of anthra- 
cite, and it is necessary to keep one immersed in water 
while using one that has been standing in water some time. 
Newspapers require to be handled with care ; if rudely 
handled they break. Twelve pound boxes of soap, when 
re-weighed, gave but ten pounds. Hams had lost 12 per 
cent and rice 2 per cent of original weight. Eggs that have 
been on hand for a few weeks lose their watery contents 
by evaporation ; the remainder is tough and hard ; this 
has probably led to the story that our hens lay hard boiled 
eggs. 
“ 4 The mercury gained its highest point last summer on 
the 2nd day of July, when for two hours it stood at 113 0 in 
the shade. All metallic bodies were hot to the touch ; my 
watch felt like a hot boiled egg in my pocket. . . . 
“ ‘ This post, although not the most southerly, is the 
hottest military post in the United States: the highest 
temperature recorded on our books since 1850, when the 
