Materials and Formulas. 139 



crock, or other suitable shelf, and on this the copper carbonate, 

 so that it shall be at the surface of the ammonia when it is 

 poured in. After adding the ammonia, diluted as above, the 

 whole should be allowed to stand covered some time, as over 

 night, and then the un dissolved copper salt may be in great 

 part easily lifted out of the solution. Instead of the shelf a 

 suitable receptacle may be used, as a fine wire sieve. The jar 

 will need nothing but a loose cover, as the loss of ammonia will 

 be slight at that degree of dilution. 



" The clear solution thus obtained, containing from 3 to 4 per 

 cent of ammonia gas, must be diluted as described above, in no 

 case less than 13 or 15 fold, better, for the safety of the plant, 

 20 fold or more. 



" Those directions which recommend so much ammonia (what- 

 ever it may be) to be used as may be necessary to dissolve the 

 copper salt and then to dilute to a given number of gallons, are 

 not only not economical, but absolutely dangerous, inasmuch as 

 it is an uncertainty just how much ammonia may be used in 

 the first instance, and hence uncertain what strength it may 

 have after dilution, when applied to the trees. It should be 

 borne in mind always that if strong ammonia is used it must 

 be diluted from first to last at least 100 fold, and better con- 

 siderably more. 



" The solubility of copper carbonate in ammonium carbonate 

 has been studied but not yet sufficiently for report." 



After the copper carbonate has been dissolved in ammonia 

 water, it should be used by taking as much of the fluid as con- 

 tains 1 ounce of dissolved copper carbonate, and this is then 

 diluted with 9 gallons of water. These proportions should be 

 retained when either larger or smaller quantities of the fungi- 

 cide are desired. 



The ammoniacal solution of copper carbonate possesses some 

 decided advantages. It is a clear solution entirely free from 

 sediment, and can therefore be applied as readily as water. 

 Another favorable point is that it may be used quite freely 

 upon maturing fruit, and also upon flowering plants, without 

 leaving any conspicuous stain. When certain plants require 

 spraying with a fungicide shortly before the crop is harvested, 

 this preparation is an excellent one to use. In efficiency it also 

 ranks high, being clearly surpassed in this respect only by the 



