Diseases op the Potato. 321 



" Oxalic acid seems to have a tendency * * * to reduce 

 the percentage of scab. 



" By the use of ammonium sulphate and probably muriate and 

 sulphate of jDotash, Ivainit and common salt in connection with dis- 

 solved phosphate rock, dissolved bone, or dissolved bone black, soils 

 which now tend to produce scabby tubers, would probably become 

 less favorable to the disease. It is possible that a rational system of 

 rotation of crops which would include no heets or other root crops, 

 and perhaps no cabbages, would also help to alleviate the condition 

 in such soils." 



21 



