THE ARGENTINE ANT : DISTEIBUTION AND CONTROL. 



19 



The Xickels siriip^ was then drained from- its jar and was found 

 to weigh 160 grams. The jar and crystals were then weighed, the 

 crystals dissolved out of the jar, and the weight of the jar subtracted 

 from the total weight of the jar and crystals. It was found that 333 

 grams of sugar crystals were present. 



Grams. 



Weight of sirup when first made .- 660. 23 



Weiglit of sirup remaining + sugar crystals 493. 00 



Water p'assed off by evaporation 167. 23 



The 660.23 grams of sirup contained 1.333 grams of sodium arsenite with a 



poison content of 0.202 per cent. 



The 160 grams of sirup remaining contained 1.333 grams of sodium arsenite. 



The poison content was now 0.836 per cent. 



The sirup with tartaric acid had a small precipitation. As the 

 Brix had been raised 7.4 per cent through evaporation, the poison 

 content was very slightly 

 raised. This sirup now 

 weighed 043.35 grams, the 

 color and sweetness being still 

 quite stable. 



Immediately after prepar- 

 ing these two sirups, April 

 23, 1914, 2 fruit jars of each, 

 containing 1^ gills of sirup 

 apiece (without honey) , were 

 set out along heavy ant trails 

 in the Horticultural Hall. 

 Absolutely clean and odorless 

 sponges were used. 



For the first 4 days the ants 

 showed a preference for the 

 old type of sirup (without 

 the tartaric acid) but for the 

 next 21 days they showed no 

 preference. Then one jar of 

 the old sirup was abandoned. 

 This proved to be partially decomposed. On moving to another spot 

 it was attended for 10 days more, then abandoned completely. Thus 

 for a total of 35 days this jar attracted the ants. Seven days later 

 the other jar of this sirup was abandoned and no matter where placed 

 neither jar had any attraction for the ants. 



1 Figure 3 shows the small quantity of sirup that still remained, as well as the large 

 bulk of sugar crystals which had formed in the jar. The jar containing the acidified 

 sirup is placed at the side for comparison. 



Fig. 2. — Comparison of the improved sirup (right) 

 with the Nickels sirup (left), showing the amount 

 of sirup left in each and the amount of sugar in 

 the Nickels sirup, (Original.) 



