Plate 3. — Influence of increasing amounts of 

 quicklime and potassium hydrate on grey speck dis- 

 ease. — The plants in the pots at the very left in each 

 photograph received only PNK. — KOH was added to 

 all pots, except those shown at the left in each photo- 

 graph, top row: 6 g, middle row: 12 g, bottom row: 

 18 g. — CaO was added to all pots, except the first two 

 from the left, in each photograph, as follows, 3: 15 g, 



4: 30 g, and 5: 45 p. 



