12 THE RUBBER INDUSTRY 



Rivers Beni, Purtis, and Jurua, and the Acre division 

 of Brazilian territory, there is little doubt that the 

 average of 99 inches is applicable equally to those 

 sections of Bolivia and Brazil, and may be taken 

 approximately as the basis generally in the Amazon 

 Valley. The maximum rainfall recorded in 1911 was 

 4*70 inches in twenty-four hours, at Porto Velho. At 

 the same place the average for five years, from July i, 

 1907, to June 30, 1912, was I03'96 inches. 



The moist heat prevalent throughout the Amazon 

 Valley is conducive to the many climatic diseases 

 common to tropical zones. Mosquitoes, flies, and many 

 other insects, constitute a pest and cause of infection 

 difficult to resist. Malaria, blackwater fever, and 

 similar forms of illness, are constantly in evidence. 

 Beri-beri and dysentery are common evils. Yellow 

 fever has been stamped out of Para, and the necessary 

 sanitary measures have been taken to eradicate this 

 plague from Manaos, where it has been endemic for 

 many years past. Except in the more populous centres, 

 such as Para, Manaos, Iquitos, and a few other places, 

 it is a practical impossibility to grapple with the 

 question of sanitation in the Amazon Valley. With 

 a scanty population scattered over an enormous area, 

 there is probably less than one inhabitant to the square 

 mile ; and to establish any effective system of medical 

 assistance, dispensaries or hospitals, is out of the ques- 

 tion under existing conditions. Something can be 

 done to improve the welfare of the dwellers in the 

 various small towns and villages, but this can be carried 

 out only at a very heavy cost, and will require years of 

 steady effort to achieve. To go farther, and attempt 



