348 
differs from it only in being slightly less injurious to the foliage. It was diluted 2 
gallons. The treated rows were 1£ grades better than adjacent untreated rows on 
September 2, and 1 and 1 better on October 13. The commercially prepared Bruns¬ 
wick green may not possess the injurious qualities to so high a degree as the freshly 
prepared precipitate and is worthy of a trial. 
No. 16.— COPPER SULPHITE MIXTURE. 
(Rows 16 and 16‘.) 
14.90 grams cupric sulphate (CuS0 4 , 5H 2 0). 
37.25 grams sodium hyposulphite (Na 2 S 2 0 3 , 5H 2 0) (U. S. Dispen., 15th ed., 
p. 1330). 
1 gallon of water. 
Chemical notes .—Cupric sulphate is in excess in the supernatant fluid. The pre¬ 
cipitate settles rapidly, is of a dirty greenish-yellow color, and the proportions of the 
ingredients have little to do with the rapidity of subsidence of the precipitate. I am 
uncertain as to its composition. 
Remarks .—This mixture, although scarcely more difficult to prepare than ammo- 
niacal solution, covers the foliage no better, adheres no better, and proved very inju¬ 
rious, even after being diluted to 2 gallons. It was, however, more effective m 
retarding the progress of the disease. The treated rows were 14 and 14 grades bet¬ 
ter than adjacent untreated rows on September 2, and 0 and 2 better on October 13. 
It is doubtful if the mixture can be modified so as to fit it for use. 
No. 17.— FERRIC CHLORIDE AND PHENOL MIXTURE. 
(Rows 17 and 17 l .) 
36.46 grams ferric chloride (Fe 2 Cl 3 -f- H 2 0). 
36.46 grams phenol (CellaOH) (U. S. Dispen., p. 48) (carbolic acid). 
1 gallon of water. 
Chemical notes .—This forms a tar-black solution, emitting fumes of carbolic acid. 
The phenol used was of commercial strength, not crystallized, and equals 20 per 
cent of the crystallized. The percliloride of iron used has a formula of Fe 2 Cl 3 , 
according to Watts, 1865, p. 377, but the amount of Avater was not obtainable. 
Remarks .—This mixture is slightly more difficult of preparation than ammoniacal 
solution, but extremely disagreeable to apply and highly injurious to the foliage. 
Dilution to 2 gallons seems to reduce the injury materially. In retarding the pro¬ 
gress of the disease it proved less effective than ammoniacal solution. The treated 
rows were 1^ and 1| grades better than untreated adjacent rows on September 2, 
and 0 and | better on October 13. It is a mixture altogether too obnoxious to Avar- 
rant further trial. 
NO. 18.— FERROUS FERROCYANIDE MIXTURE. 
(Roavs 18 and 18 1 .) 
22.94 grams ferrous sulphate exsiccatus (FeS0 4 , H 2 0). 
45.88 grams potassium ferrocyanide (K 4 FeCy fi , 3H 2 0). 
1 gallon of water. 
Chemical notes .—A light marine-blue precipitate, which becomes dark Prussian 
blue on exposure to the air. The formula is probably Fe 2 FeCy*, with potassium 
ferrocyanide present (Watts, 1865, p. 334). The chemical reaction would be 
Fe 2 S0 4 , H 2 0 + K 4 FeCy 6 , 3H 2 0 = Fe 2 FeCy 6 + K 4 (S0 4 ) 2 + 4H 2 0. The ferrous ferrocy¬ 
anide is therefore combined in the mixture Avith potassium sulphate. 
Remarks .—This mixture is considerably more difficult of preparation than ammo- 
niacal solution, but covers the foliage as Avell and adheres with remarkable tenacity, 
far surpassing ammoniacal solution in this respect. It proved less .effective in 
retarding the progress of the disease and Avas slightly injurious. The treated toavs 
were 1 and grades better than the adjacent untreated rows on September 2, and 0 
and 2 better on October 13. It is a mixture seemingly possessing little fungicidal 
value. 
