New York AGRICULTURAL EXPERIMENT STATION. 481 
Paris green or other arsenicals which are recommended against 
the insects, may be combined with Bordeaux mixture, but not 
with the ammoniacal solution of copper carbonate. 
Ammonical solution of copper carbonate.-—The formula usually 
given for making this solution is as follows: Dissolve five ounces 
of copper carbonate in three pints of ammonia of 26° strength. 
When ready to apply, dilute with water so as to make fifty gal- 
lons. The undiluted solution may be preserved for some time in 
tightly closed vessels. 
Penny finds”’ that the use of the strong undiluted ammonia in 
dissolving the copper is wasteful and unsafe. He recommends 
the following method of making the solution. “To one volume 
of 26° Beaumé ammonia (the strong ammonia of commerce) add 
from seven to eight volumes of water. Then add copper car- 
bonate, best in successive quantities, until a large portion remains 
undissolved. The mixture should be vigorously agitated during 
the solution and finally allowed to subside, and the clear liquid 
poured off from the undissolved salt. A second portion should 
then be made by treating the residue of the former lot with more 
ammonia diluted as before, then with the addition of fresh cop- 
per carbonate, in every case with vigorous stirring or agitation. 
The method of making in successive lots will result in a richer 
solution of copper, at least unless an unwarranted length of time 
be taken.” He finds that much less ammonia is required to dis- 
solve a given amount of copper carbonate in this way than ac- 
cording to the method formerly followed of adding the strong, 
undiluted ammonia directly to the copper carbonate. 
CHLOROSIS OR YELLOW LEAF. 
The name is applied to a grape disease in which the foliage turns 
yellow, later becoming brown. It is common in some parts of the 
State. 
26 Del. Agr. Exp. Sta. Bul. 22. 
