IRIS LEAF lU.OTCII. 



451 



The ultimate question is how to get rid of the parasite and save the 

 plants. This is a question not easily solved where the pest is an internal 

 parasite, developed outwards from the tissucis. All that I am ahle to 

 suggest is that of spraying with ammoniacal copper carhonate solution, 

 which has been recommended as having been tried with success. Of 

 course one cannot be too careful in the clearing away of diseased leaves, and 

 burning them so as to destroy the conidia and check the spread of the 

 disease. In the case of the allied speci(!S, which attacks Carnations 

 [Gard. CJiron. 1886, p. '244) it is said that spraying with potassium 

 sulphide checks the disease. 



It may be useful to add tliat tlie ammoniacal solution of copper 

 carbonate consists of 



Water 10 gallons 



Carbonates of copper .... 1 ounce 

 Carbonate of anniionia . . .5 ounces 



Mix the carbonate of copper and the carbonate of ammonia and dissolve 

 in about a quart of hot water ; when dissolved add sixteen gallons of cold 

 water. There is also another method of preparation, as well as that of 

 potassium sulphide solution, which may be found in Massee's " Text-book 

 of riant Diseases," p. 37. 



