Materials and Formulas. 145 



When the crystals are dissolved and the liquid has cooled, add 



Ammonia (22 Beaume) 1| pints. 



Water, to make 25 gallons. 



This fungicide has a caustic action upon foliage and cannot 

 be recommended with safety. According to Professor Chester, 

 " the probable reactions taking place in the preparation of the 

 eau celeste are : l 



1. 3[CuSO 4 , 5H 2 O] + 4NH 4 HO 



normal copper sulphate ammonia 



= CuSO 4 , 2Cu(OH) 2 + 2(NH 4 ) 2 , SO 4 + 15 H 2 O. 



basic copper 

 sulphate 



2. CuS0 4 , 2 Cu(OH) 2 + 2(NH 4 ) 2 , SO 4 + 8 NH 4 HO 



In excess. 



= 3(CuSO 4 , 4 NH 3 , H 2 O) + 9 H 2 0." 



ammonium copper sulphate 



Nevertheless, the fungicide is not a safe one to use. 2 

 EMULSIONS. Of the insecticides which kill by contact there 

 are none more effective than those which are composed of emul- 

 sion of soap solutions and such penetrating liquids as mineral 

 oils. The kerosene emulsions are the best known and most 

 generally used. (See under KEROSENE.) But the following 

 liquids have been recommended 3 as suitable substitutes for this 

 oil. The percentages of the amounts to use in the emulsions 

 are given for comparison : 



Benzine emulsion, containing from 0.5 to 2.0 per cent. 



Kerosene emulsion, containing from 0.5 to 2.0 per cent. 



" Nitro benzina " emulsion, containing from . . 0.5 to 0.75 per cent. 

 Bisulphide of carbon emulsion, containing from 0.5 to 0.75 per cent. 



The general method of procedure for preparing these emul- 

 sions is as follows : 



" Active principle (oils, etc.) 0.5 to 1.0 per cent. 



Soft soap 0.5 to 2.0 per cent. 



Water of preparation 1.0 to 3.0 per cent. 



Water of dilution 99.0 to 97.0 per cent." 



1 Del. Agrie. Exp. Sta. kik Ann. Kept. 1891, 68. 



2 Perret, in Jour. (VAg. Prat. 188T, June 23, 878, says that the precipitate 

 first formed when ammonia is added to a copper sulphate solution is a hydrated 

 oxide of copper (oxide de cuivre hydrat-j). The clear liquid contains the sulphate of 

 ammonia, which has a tendency to injure foliage. 



3 Ad. Targioni Tozzetti," Mostra di Sostanze e di Emulsion! Insetticide," 1891, 17. 



L 



