CONTROL OF GRAPE-BERRY MOTH. 19 
The lime was slaked to a smooth paste with 18 ounces of water. 
The arsenic acid was diluted with the remaining 16 ounces of water 
and the diluted acid added to the lime paste a little at a time. The 
paste was stirred vigorously during the mixing. With each addi- 
tion of acid the lime had a tendency to granulate, but continued 
stirring restored the smooth pasty condition. A sample of the final 
paste was analyzed by the United States Bureau of Chemistry under 
miscellaneous laboratory No. 24714 as follows : 
Moisture 69. 7 
Total CaO (as received) 15.08 
Total As 2 5 (as received) 12.04 
Water soluble As 2 B .02 
5 grams samples in 1,000 c. c. C0 2 free water ; equivalent to 2 pounds to 
50 gallons. Free lime calculated as calcium hydroxid Ca(OH)2 4.4 per cent. 
Paste made according to this formula was used on grapes in 1918 
at the rate of 4 pounds to 50 gallons of water. Grape-berry moth 
infestation failed to develop in numbers sufficient for the desired 
comparisons in any one of the four vineyards in which these ma- 
terials were used. The spreading qualities and effects on grape 
foliage, however, are important. The arsenicals were applied either 
in Bordeaux 2-2-50 or with stone lime 2 pounds to 50 gallons added 
to the mixture. In all cases resin fish-oil soap at the rate of 1 
pound to 50 gallons was also added. The paste made from sodium 
arsenate spread equally as well as the commercial arsenate of cal- 
cium powder or arsenate of lead powder. The paste made from ar- 
senic acid failed to spread as well and when dry it was not a smooth, 
even coating such as is desired. In no case could foliage injury be 
attributed directly to the use of either of the home-made arsenate of 
calcium pastes. 
Spreaders and Adhesives. 
Because of the partial failure of arsenate of lead and Bordeaux 
to spread over or " wet " the individual grapes in the grape clusters, 
various materials have been added to these to facilitate the spreading 
process. 
The qualities desired in such a spreader are (1) quick- wetting 
power, (2) adhesive power when dry, and (3) that it be easily pre- 
pared for use. In addition, a material to be suitable must be com- 
patible with Bordeaux mixture and arsenicals and also be compara- 
tively cheap. 
Former investigations 1 had shown that some form of soap was 
the most practical material for the purpose. When these investiga- 
tions were undertaken various soaps were recommended by differ- 
1 Isely, Dwight, op. cit. 
