347 
NO. 13.— CUPRIC SULPHATE, AMMONIA, ANI) SOAP MIXTURE (SOAP EAU CELESTE). 
(Rows 13 and 13'.) 
14.90 grams cupric sulphate (CuSO,, 5H 2 0). 
0.75 c. c. aqua ammonia 26 per cent (NH 4 HO). 
44.70 grams palm soap. 
1 gallon of water. 
The cupric sulphate was dissolved in water and the ammonia added to it. The soap 
previously dissolved in warm water was then added and the whole mixture churned 
until a heavy foam was formed. 
Chemical notes .—Palm soap was used as being the most available, hut other kinds 
of soap answer the purpose perfectly. This mixture is remarkable in its jiroperty 
of spreading over the foliage. The waxy cuticle of the pear leaves in no way pre¬ 
vents a complete coating from being formed. It is of indefinite composition and too 
complex to he determined. 
Remarks .—Although more difficult of preparation than ammoniacal solution, this 
covers the foliage and adheres to it in a manner unsurpassed by any mixture yet 
employed, to my knowledge. It proved much more effective in retarding the progress 
of the disease and was not in the least injurious. It was tested upon the foliage of 
hearing pear trees and showed remarkable efficacy in checking leaf-blight. It was 
also used upon plum and horse-chestnut seedlings without the least injurious effect. 
Upon grape foliage it proved somewhat injurious. The treated rows of pear seedlings 
were 1£ and 1 grades better than adjacent untreated rows on September 2, and 2 and 
2 better on October 13. It is the most promising of all the 25 preparations employed. 
It is believed that the subject of soap mixtures is worthy of more extended investi¬ 
gation than it has hitherto received. 
No. 14.— CUPRIC OXYCHLORIDE MIXTURE (FORM A). 
(Rows 14 and 14 1 .) 
14.90 grams cupric sulphate (CuS0 4 , 5H 2 0). 
29.80 grams chloride of lime (CaOChX $)• 
1 gallon of water. 
Chemical notes .—A sooty black precipitate, often with a brownish tinge, formed 
best when both cupric sulphate and chloride of lime are in concentrated solution. 
The proportions of lime and sulphate are highly important. The addition of a small 
amount produces a green precipitate (No. 15), while the addition of a greater portion 
causes it to turn to a sooty black color on standing. Free chlorine seems to be given 
oft' in the reaction. No cupric sulphate was detectable in the supernatant fluid. I 
was not able to determine the composition of this compound and believe little is . 
known of it further than that it is probably an oxychloride. 
Remarks .—This mixture is more difficult to prepare and apply than ammoniacal 
solution, spreads as well, but does not adhere nearly as well. It proved less effective 
in retarding the progress of the disease and was very injurious to the foliage, scorch¬ 
ing it severely and necessitating a dilution to 2 gallons. The treated rows were ^ 
and 14 grades better than untreated adjacent rows on September 2, and 0 and £ better 
on October 13. It is a mixture with nothing to recommend it. 
No. 15.— CUPRIC OXYCHLORIDE MIXTURE (FORM R, TRIBASIC). 
(Rows 15 and 15'.) 
14.90 grams cupric sulphate (CuS0 4 , 5H 2 0). 
21.28 grams chloride of lime (CaOCl 2 ) (?). 
2 gallons of water. 
Chemical notes .—This form of the oxide, according to Prescott and Johnson ( l. c.) } 
is known in commerce as “ Brunswick green/’ and is used as a pigment. No cupric 
sulphate was in excess in the supernatant fluid. In Watts’Dictionary, edition of 
1889, p. 260, it is stated that Brunswick green has the formula CuCl 2 , 3CuO, 4H 2 0. 
Remarks .—This mixture is identical in method of preparation with No. 14, and 
