700 



I'KOThX'TION ArJAINST DISEASES. 



Fig. 298. — Oaks uear a manufacturing town, the foliage damaged h\ acid fumes, 

 photographed August, 1882.* 



Fig. 299.— Same oaks' photographed July, 1888, several years' cumulative injury 

 having killed the trees.* 



* From Crooiiian Lecture by Marshall Wartl (_ri(Ir p. (J?!), 



