BISULPHIDE OF CARBON. 213 
2. The greater number were under the violet 
glass and bisulphide. 
2.30 ” 2 ” 
3. Almost all were under the glass and bisulphide. 
The addition of the bisulphide thus caused the violet 
glass to be distinctly preferred to the chlorate of copper. 
I then took a solution of sulphate of nickel, almost 
exactly the same tint as, or a shade paler than, the 
chlorate of copper. 
At 3.45 the ants were under the violet glass and 
bisulphide. 
4. ” > ” 
5. ob) bP) 39 
October 18. 
7 AM. ” ” ” 
8. About half of the ants were under each. 
Here the effect was even more marked. 
T then took some saffron 1 inch in thickness and of 
a deep-yellow colour. 
12.45 The ants were about half under each. 
1. Most of the ants were under the violet glass 
and bisulphide. 
1.15 2 29 9 
2. Most of the ants were under the satfron. 
Here, again, we have the same result. 
I then tried the different-coloured glasses, all of 
which, as I had previously found, are unmistakably 
preferred to the violet. It remained to be seen what 
