Jan., 1919] Effects of the Eruption on Vegetation 175 



quence. In the second zone, covering parts of Kodiak and 

 Afognak Islands, the ashfall was so heavy as to do great damage 

 to the smaller plants, but the trees and bushes that protruded 

 were comparatively unaffected. The third zone includes those 

 areas of slighter injury on the mainland. In the fourth zone 

 the trees and bushes were killed but the grass has come back 

 without permanent injury. In the fifth zone not only were the 

 trees killed, but the ashfall was so heavy that the herbage as 

 well was destroyed except where the ground was later cleared. 

 In the sixth zone every vestige of life was consumed by fire, 

 leaving the country absolutely sterile. The areas covered by 

 these zones are shown by the map given herewith. (See page 

 174). It will be observed that they are not concentric belts 

 lying one inside the other, but are to a considerable extent 

 independent, occupying different sectors of the area around the 

 volcano. Because of the geographical peculiarities of the 

 country, moreover, they intergrade very little, at least in those 

 areas so far explored, but are rather sharply separated from 

 each other by definite geographical boundaries. 



OUTLYING AREAS INJURED BY ACID RAINS. 



On account of the unsettled condition of the country affected, 

 and particularly because the interests of the scanty population 

 are not agricultural, the damage to plants at great distances 

 from the volcano was a matter of very much less concern than it 

 would have been in a populous agricultural country. Observa- 

 tions of damage to plants were therefore never recorded at all in 

 many cases, and where published were simply printed as news 

 items in the local papers. The records are, therefore, much 

 scattered and difficult to secure, but it should not be supposed 

 on this account that damage to vegetation in the outermost zone 

 was insignificant in amount. 



At La Touche in Prince William Sound, some 300 miles 

 east of the volcano, Mr. F. R. Van Campen, then super- 

 intendent of the mines, in a private letter, states that following 

 the eruption the rain was so acidulated by the fumes as to cause 

 stinging burns wherever it touched the flesh. He had his 

 chemist analyze this rain and found that the trouble was caused 

 by sulphuric acid which was present in considerable quantity. 

 Unfortunately the analysis giving the precise concentration of 

 the acid has been lost. This acid rain did serious injury to the 



