INFLUENCE OF THE DESERT ON LIFE. 10g 
Deer and peccary are abundant in deserts in Sonora in which the only 
available supply of open water is to be found in the cacti. The endurance 
of the camel is well known, and some of the best authenticated evidence 
upon the matter comes from Australia. The camels of the Tietkins 
party in 1891 and 1892 made a march of 537 miles in 34 days without a 
drink. These animals take water every day when a supply is available, 
but it is their capacity for accommodation that has made them such a 
potent factor in transportation in the deserts of Asia, Africa, and Aus- 
tralia. Other animals, including the common domestic sheep, are also 
capable of making such changes in their habits that they may go for 
weeks without a drink. 
Man and his most constant companion on the desert in America, 
the horse, are comparatively poorly equipped against the rigors of the 
desert. A horseman may go from the morning of one day until some 
hour of the next in midsummer and neither he nor his horse will incur 
serious danger: experiences of this kind are numerous. If the traveler is 
afoot, abstinence from water from sunrise to sunset is a serious inconven- 
ience to him, and if he continues his journey, the following morning his 
sufferings may so disturb his mental balance that he may be unable to 
follow a trail, and by the evening of that day, if he has not come to some- 
thing drinkable, he may not recognize the friendly stream in his way; 
instances are not unknown in which sufferers from thirst have forded 
streams waist deep to wander out on the dry plain to a grisly death. 
Some estimate may be made of the actual amount necessary from 
the fact that a worker at the Desert Laboratory during the course of an 
ordinary day in May, at Tucson, consumed 16 pints of water. A horse 
would have used rs or 20 gallons in the same time. A walk of 3 or 4 
miles was taken, but no special muscular effort beyond this was involved. 
A march across the desert in midsummer would increase this quantity by 
half. Under such circumstances, a canteen of less capacity than a gallon 
is a toy, and one of real usefulness should contain at least twice that 
amount. The most notable example of endurance of thirst is that of a 
Mexican prospector hunting for a ‘“‘lost mine’’ near the old Camino del 
Diablo, or trail from Sonora to Yuma, who made camp safely after being 
out for eight days with a supply sufficient forone. This experience is not 
likely to be duplicated soon, although it is reported that Indians often 
go as long as four days without water. (W J McGee, Desert Thirst as a 
Disease, Interstate Medical Journal, 1906, vol. 13, No. 3, 1906.) 
The experience of the field expeditions from the Desert Laboratory 
demonstrates that saline or alkaline waters which contain as much as one- 
fourth of 1 per cent of salts may be used for periods of many days without 
serious discomfort, but if the proportion be increased to one-third of 1 
per cent only hardened travelers may use it, while water which contains 
as much as one-half of 1 per cent is inimical to health and comfort, 
