FISH OIL AS ADHESIVE IN ARSENATE-OF-LEAD SPEAYS / 
In the Dukes Park area 7 plots were selected, each containing 
l 2 / 9 acres. The same adhesives were used here as in the Watchung 
Ridge plots, with the exception of the proprietary miscible oil. 
Another area of seven 1-acre plots, containing a mixed growth, was 
selected in Saugus, Mass., and in these plots the same adhesives were 
used as in the Watchung Ridge area, except the proprietary miscible 
oil and the soap. A small area was selected in Melrose Highlands, 
Mass., for experiments with the proprietary miscible oil. 
The lead oleate, so called, was a combination in paste form of lead 
oleate and lead arsenate. As it contained in all but 13.53 per cent of 
arsenic oxide, 50 pounds of it was required to equal the poison 
strength of 25 pounds of ordinary powdered arsenate of lead, since 
the latter contains about twice the percentage of arsenic oxide. 
The season of 1924 was an excellent one for testing the adhesive 
qualities of different substances, the rainfall on the plots in both New 
Jersey and Massachusetts being above normal. After the spraying 
was finished and the materials thoroughly dried, representative col- 
Fig. 2. — Diagram of plots at Watchung Ridge, Somerville, N. J., used in 1924 for tests of adhesives 
in arsenate-of-lead sprays 
lections of the foliage were made from each of the plots. After each 
moderate or heavy rain another collection of foliage from each of the 
plots was made, care being taken to select samples which were not 
blotchy or oversprayed and which were located in the open where 
they would be subjected to the full force of the rain during the season. 
The amount of spray material washed off was estimated by compar- 
ing it with the foliage taken from the plot shortly after the poison 
was applied. The same method was continued throughout the season. 
Careful examinations of the foliage were also made to note if any 
injury had taken place. The following year plots were sprayed with 
arsenate of lead mixtures both with and without an adhesive, collec- 
tions of the foliage were made at different periods during the season, 
and chemical examinations of the spray remaining on the foliage 
made. The results of these tests showed that they did not differ 
very materially from those made by comparison during the season 
of 1924. 
