Nov. 27,1916 Nicotine-Sulphate and Fish-Oil-Soap Sprays 
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EXPERIMENTAL WORK 
GROUP I 
The effectiveness of the sprays containing nicotine sulphate in the 
ratio of 1 to 630 with various amounts of soap to 50 gallons of solution 
is represented by the efficiency curve for this group in figure 1. The 
curve begins with 1 pound of soap to 50 gallons of spray, at 75 per cent 
efficiency. It gradually rises with the increased amounts of soap in 
the formulae to 90.8 per cent, which is the efficacy of 4 pounds of soap 
plus 50 gallons of a i-to-630 Solution of nicotine sulphate. The solutions 
containing greater concentrations of soap than the above lose effective¬ 
ness, and the curve drops to 85.3 per cent at 6 pounds and to 80.1 per 
cent for the formula which contained 7 pounds of soap. 
The degree of wetting of the solutions in group 1 is shown by a curve 
in figure 1. This is based on the arbitrary comparative values in the 
column at the right. The wetting power of the formula containing 
1 pound of soap to 50 gallons of i-to-630 nicotine solution is 103, the 
curve then rises to 193 for the formula containing 3 pounds of soap. 
A sudden increase in the wetting power takes place at this point, the 
curve going to 615 for 4 pounds, 628 for 5 pounds, 743 for 6 pounds, and 
750 for 7 pounds of soap to the 50 gallons of i-to-630 nicotine-sulphate 
solution. 
GROUP 4 
Group 4 is one of eight formulae for fish-oil-soap solutions at ratios 
between 2 and 8 pounds to 50 gallons of water. The efficiency curve 
for group 4 is given in figure 1. The efficacy of a solution of 2 pounds of 
fish-oil soap to 50 gallons of water is 36.3 per cent. From this the curve 
rises to 73.7 per cent for a solution which contained 6 pounds of soap to 
50 gallons. Greater concentration of the solutions gave but slight 
increase in the effectiveness, as is shown by the curve, which remains 
only a fraction above 75 per cent for the solutions containing 7 and 8 
pounds of soap. 
The wetting-power curve of the solutions in group 4 is shown in figure 1. 
The curve begins at 307 for the solution containing 2 pounds of soap and 
rises gradually to 363 for 3 pounds of soap. From this point the wetting 
power being greatly increased by further additions of soap, the curve 
rises to 645 for 4 pounds and 1,067 f° r 5 pounds of soap. Further con¬ 
centration of the solutions increased the wetting power very little, a 
solution of 8 pounds of soap having the wetting value of 1,112. 
DISCUSSION OR GROUPS I AND 4 
The results of these experiments indicate (i) that the addition of 
nicotine sulphate to fish-oil-soap solutions decidedly increases their 
effectiveness in destroying aphids; (2) that the efficiency of nicotine 
