343 
No. 2.— COPPER BORATE MIXTURE. 
(Rows 2 and 2 l .) 
14.90 grams cupric sulphate (CuS0 4 , 5H 2 0). 
16.39 grams sodium borate (borax) (Na 2 B 4 0 7 , 10H 2 O). 
1 gallon of water. 
Chemical notes .—The borate has probably the formula (Cu 2 H)B0 3 + h aq., which 
on being decomposed by the water becomes CuB0 2 . 3CuHO -f- £ aq. (see Watts’ 
Dictionary of Chemistry, old ed., 1863, p. 643). The substance was used as a dried 
precipitate by Lodeman,* but it was first proposed in its present form by W. T. 
Swinglo and used for rust of wheat.t The reaction would be represented by the 
following formula: CuS0 4 , 5H 2 0 -f- Na 2 B 4 O 7 ,10 H 2 0 = CuB 4 0? -f- Na 2 S0 4 4- 15H 2 0. It 
is therefore sprayed upon the plant in the form of a copper borate and a sodium 
sulphate. 
Remarks .—This mixture is more difficult to prepare and does not cover the foliage 
as well, but adheres better than ammoniacal solution. It proved more effective in 
retarding the disease and was not injurious. The treated rows were 1 and 2 grades 
better than adjacent untreated rows on September 2, and and 1 on October 13. It is 
one of the most promising mixtures as regards efficacy, and might be tried stronger. 
NO. 3.— COPPER BASIC CARBONATE MIXTURE. 
(Rows 3 and 3 1 .) 
14.90 grams cupric sulphate (CuS0 4 , 5H 2 0). 
14.90 grams sodium carbonate (Na 2 C0 3 -f- 10H 2 O). 
1 gallon of water. 
Chemical notes .—This precipitate when first formed probably has the following 
formula: CuC0 3 , Cu0 2 H 2 , H 2 0, but it rapidly becomes CuC0 3 , Cu0 2 H 2 (see Watts’ 
Dictionary 1888, p. 698). It is the mixture previously known as the “Masson” 
mixture and is identical with the first compound formed in the preparation of modi¬ 
fied eau celeste. The reaction is expressed as follows: CuS0 4 , 5H 2 0 + Na 2 C0 3 , 
10H 2 O = CuCO;! -f- Na 2 S0 4 -f- 15H 2 0. The preparation, therefore, reaches the plant 
in the form of a copper carbonate and a sodium sulphate combined. 
Remarks .—This mixture is more difficult to prepare than the ammoniacal solution, 
but it covers the foliage and adheres about as well. It proved more effective in 
retarding the progress of the disease and was not injurious. The treated rows were 
1 and 2 grades better than adjacent untreated rows on September 2, and 3 and 2 on 
October 13. It is one of the most promising of the new fungicides as regards efficacy 
and should be tried stronger. 
No. 4.—AMMONIACAL COPPER CARBONATE SOLUTION. 
(Rows 4 and 4 1 .) 
7.03 grams cupric basic carbonate (copper carbonate) (2 CuO, C0 2 (0H) 2 ). 
50 c. c. of water. 
150 c. c. of aqua ammonia, 26 per cent (stronger water of ammonia) (NH 4 HO.) 
1 gallon of water. 
The carbonate is wet up in the small quantity of water to a thin paste, and after 
a few minutes the ammonia is added and the solution thus formed made up to 1 
gallon. 
Chemical notes— The reactions for this fungicide, which is the ammoniacal solution 
as ordinarily used, with the addition of more ammonia than common, have been pub¬ 
lished by F. D. Chester in the Journal of Mycology, vol. vi, p. 23. A large quantity 
of ammonia was found necessary to a complete solution of the carbonate, but it was 
highly injurious. 
* Lodeman, E. G. N. Y. Cornell Agr. Exp. Sta., Bull. No. 35, pp. 327, 331. 
t Jour, of My col., vol. vu, No. 3, May, 1893, p.201. 
23192—No. 4-2 
