342 
whole product of the chemical reaction which takes place when two 
or more salts in solution are added together. In the majority of cases 
the mixture was a solution of sodium or potassium sulphate, with an 
insoluble metallic salt, either copper, zinc, or iron. The remarks upon 
the effect of the different preparations are designed as an aid to those 
who may wish to make further trials with them. 
In order to get more definite ideas as to the preventive effects of the 
various preparations, six grades were established. These were arbi¬ 
trarily chosen as follows: Grade 1, in which were placed all rows in 
which the injury to the foliage amounted to from 1 to 15 per cent; grade 
2, from 16 to 30 per cent; grade 3, from 31 to 50 per cent; grade 4, 
from 51 to 70 per cent; grade 5, from 71 to 85 per cent; grade 6, from 
86 to 100 per cent. The grade in which each row was placed was 
decided on after a careful examination and comparison by Prof. Beach 
and myself. It is believed that the comparative injury done by the 
disease upon the different rows is for all practical purposes shown as 
faithfully in this way as it could have been if every seedling had been 
counted and its condition tabulated. The grading was done twice, 
once on September 2 and again on October 13. 
Under the description of each preparation there is given a compari¬ 
son of each treated row with the two adjacent untreated ones. In order 
to make a fair comparison the average of the two untreated rows was 
taken, and with this the treated row was compared. 
Mixtures and solutions tested .—In the twenty-five mixtures described 
below, where not otherwise stated the ingredients were each dissolved 
separately in 1 quart of water and thoroughly mixed together. The 
mixture was then made up to 1 gallon, and 1 quart of this was applied 
to each row of 130-150 seedlings on each of the following dates: (1) 
June 3-5, (2) June 14 and 15, (3) July 6, (4) July 20, (5) August 1, (6) 
August 15. 
NO. 1.—BASIC CUPRIC ACETATE MIXTURE. 
(Rows 1 and l 1 .) 
11.90 grams of copper acetate (basic refined powder). 
Wet up to a thick paste and allowed to stand 24 hours or more before mixing in 1 
gallon of water. 
Chemical notes.— This refined powder is evidently a tribasic acetate, and, according 
to Watts' Dictionary of Chemistry, new edition, vol. i, p. 10, has the formula 2CuO, 
Cu A' 2 2aq. = 3CuO, Ac 2 0, Ac 2 02aq.=:2(H0, CuA')Cu(OII) 2 . The basic acetate has 
been used previously (see Div. of Veg. Path. Bull. No. 3, pp. 11 and 65. Also 
Beucker, Georges. <Prog. Agr. et Vit., Dec. 7, 1890, pp. 510-516.) 
Remarks .—This mixture is easier to prepare, covers the foliage as well, and 
adheres as well as aminoniacal solution. It proved more effective in retarding the 
progress of the disease and was not injurious. The treated rows were £and 2 grades 
better than adjacent untreated rows on September 2, and and 1 on October 13. 
(The number first mentioned, denoting superiority, refers to the original row (1); 
the second to the duplicate row (l 1 ).) 
