FISH OIL AS ADHESIVE IN ARSENATE-OF-LEAD SPRAYS 6 
INGREDIENTS AND QUANTITIES RESULTS 
feer-of- Paris:::::: 3 £ounds}W "«*! T dislodged. 
Flour 3 pounds 1 D 
Glue 3 pounds/ 
Flour 3 pounds) Dq 
Gelatine 3 pounds/ 
Casein 3 pounds 1 Spread well; better than those mentioned 
Hydrated lime 3 pounds/ above. 
HvdrXd lime::::::: ! JZndsK-** 1 fairi y ™* «■«& dMod « ed - 
PrS-ume.\-::::: l 3l>o^} s p^ d fair 'y we »; rather easi, y dislod « ed - 
Soap powder 3 pounds 1 ^ 
Casein 3 pounds/ 
Plaster of Paris 6 pounds] 
Casein 6 pounds > Do. 
Hydrated lime 6 pounds J 
Linseed oil 3 gallons. Spread well; not easily dislodged. 
In these tests it was found that the most promising materials for 
adhesives were casein, lime being added to bring it into solution, and 
linseed oil. 
IN 1922 
In 1922 both of these adhesives were given further tests, together 
with another which might prove of value. Woodland trees, such as 
birch, cherry, maple, and oak, were sprayed with these materials and 
examined frequently during the summer, the amount of spray 
washed off, if any, being noted. The rainfall during the summer of 
1922 was excessive in the section where these experiments were 
conducted. From June 7 to September 20, when the last examination 
of the foliage was made, a total of 18.71 inches of rain had fallen. 
As in 1921, the quantity specified of the adhesive taken was in each 
case mixed with 100 gallons of water and 634 pounds of arsenate of 
lead. The ingredients and quantities taken for these tests were as 
follows : 
Linseed oil 1 gallon. 
Linseed oil 2 quarts. 
Linseed oil 1 quart. 
Casein (proprietary) M pound. 
Gum Arabic It?„„v, %/ ^ i 
Potassium dichromate j Each % P ound ' 
The examination of «fche foliage on September 20 showed that the 
greater part of the spray in the plot treated with the largest propor- 
tion of linseed oil still remained on the foliage, but slightly less of 
the spray remained on the foliage in the other two plots on which 
linseed oil was used. In the plot on which casein was used only 
slight traces of the spray could be found on the foliage on September 
20, whereas in that treated with gum arabic more spray could be seen 
than in the plot last mentioned but much less than in those treated 
with linseed oil. 
IN 1923 
As linseed oil proved the best adhesive of any tried in 1921 and 
1922, it was decided in 1923 to try other vegetable oils and an animal 
oil, to find, if possible, one that would prove to be a good adhesive 
but much less expensive than linseed oil. 
