340 READINGS IN BIOLOGICAL SCIENCE 



THE DEATH OF WALTER REED 



The master detective in this story, Major Walter Reed, died of acute 

 appendicitis on November 23, 1902, in Washington. It is good to know 

 that before he died he saw the great city of Havana delivered from her 

 ancient foe, and the way made clear for the saving of his own beloved 

 country from a great plague. 



THE SEQUEL TO THE TALE 



The heroism of Walter Reed's little band of scientists and volunteers has 

 run like a golden thread through all the later work done in connection with 

 this disease. The search for the real cause of yellow fever continued even 

 after its chief carrier had been discovered. Fortunately, certain kinds of 

 monkeys were found to be susceptible to yellow fever, so it became un- 

 necessary to use human beings as subjects for experiment. However, the 

 search for the virus proved to be so dangerous that valuable lives were 

 lost until 193 1, when a yellow fever vaccine was perfected. 



Campaigns against the Aedes aegypti mosquito were so successful in 

 eliminating yellow fever from the centers where it had once been a major 

 cause of death that the manner of its spread came to be regarded as "one 

 of the best examples of a closed argument" in the entire history of medi- 

 cine. However, experiments in West Africa have proved that yellow fever 

 can be transmitted by mosquitoes other than Aedes aegypti, and within 

 the past few years the disease has been discovered in rural and jungle areas 

 in South America where no Aedes aegypti mosquitoes can be found. 



The knowledge that yellow fever is caused by a filterable virus and can 

 be vaccinated against, together with the proof that in certain localities it 

 is spread by carriers other than the Aedes aegypti, is being used by workers 

 today in their efforts to realize that noble vision which came to Walter 

 Reed just before the clock struck midnight on New Year's Eve in 1900 

 — the complete conquest of yellow fever in the 20th century. 



MENTAL DISEASE A CHALLENGE * 



WINFRED OVERHOLSER 



Mental disorder is a subject which merits the attention of every intelli- 

 gent citizen, for it constitutes to-day one of the largest and most pressing 

 social problems. It is important from the medical, public health, social and 

 economic points of view. Very nearly one half of the hospital beds of the 

 entire country are devoted to the care of mental diseases. At the beginning 



* Reprinted by permission of the Scientific Monthly, American Association for the 

 Advancement of Science. Copyright 1938. 



