BISULPHIDE OF CARBON. 213 



2. The greater number were under the violet 



glass and bisulphide. 

 2.30 „ „ „ 



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? »> )? 



"• ?5 J5 JJ 



October 18. 



7 A.M. „ „ „ 



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. Most of the ants were under the saffron. 



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 



