CHAPTER XVII. Ill 



to maintain life in human beings. A man can do without food for a 

 considerable period. Three to four days' fast is not necessarily fatal 

 or even harmful. It is claimed that men have endured fasts of con- 

 siderable periods. There is fair authentication of fasts exceeding forty 

 days. The body can endure no such deprivation of moisture, or any- 

 thing like it. The needs of the body in this respect vary with exposure 

 and exercise. Heat, dryness and work together make a heavy drain 

 on the liquid of the system. If this drain is not supplied, the entire 

 body suffers. One of the striking effects of lack of water is derange- 

 ment of the nerves and mind. The extreme sufferer becomes idiotic 

 or insane. The importance of liquid to the system is shown by the 

 injection into the veins of a saline solution, when an extraordinary 

 drain threatens or has produced collapse. In the case of severe loss of 

 blood by wounds, the recovery of system-tone by this procedure is 

 surprising. 



In a climate like ours, the water supply must never be neglected. 

 Many springs are of a small capacity. The marking of springs 

 on the forest map should indicate the amount of water delivered. For 

 springs the number of gallons or fractions of gallons delivered per 

 minute is the most convenient measure, and one comprehensible to the 

 largest number. A spring sufficient for one household might scantily 

 sustain two, and fail entirely for three households. A mountain spring 

 sufficient for one man only in the twenty-four hours may exist, but I 

 do not know of it. All the springs and streams, however, have their 

 limits of capacity in what life they can sustain. Most of them are 

 large enough to leave this question unimportant for our patrol. There 

 are a number of springs and water holes the capacity of which is 

 insufficient for twenty men with horses and pack train. Consequently 

 a patrol route and time card fixed upon certain springs for camps might 

 be perfect for two or three men, but destructive and impossible for a 

 large force. 



A military expedition from Suakim, on the Red Sea, in pursuit of 

 certain Bedouin tribes, lost nearly all its animals and was obliged to 

 retreat from the African Desert, simply because the water holes relied 

 on could not fill fast enough to supply the men and animals. 



Dalton's experiments show that man requires in the temperate 

 zone an average of fifty-two fluid ounces of water for his health and 

 vigor per diem. 



Care is required in bringing animals up to a water supply so as to 

 prevent their rushing in and spoiling the water. Of course this acci- 



