286 SIE JOHN LUBBOCK ON ANTS, BEES, AND WASPS. 



place altogether at the surface of the liquids, so that it is not ne- 

 cessary to use any large quantity. I poured them into shallow 

 glass cells ahout | inch deej), which I put, asbefore, over the ants. 

 If now they were affected mainly by the chemical rays, it must 

 appear to them to be dark under these solutions. This, however, 

 was not the case. The solutions seemed to make no difference 

 to them. I also tried quinine and uranium glass with the same 

 effect. 



In order to ascertain what colours were transmitted by these 

 several media, I then tested them with the spectroscope, and 

 with the following results : — 



The violet glass transmitted violet, blue, some green and yellow to about the luie 

 D in the spectrum or a trifle beyond. 

 „ „ (double) transmitted violet and blue with tinge of red. 



most of blue, and about to line " a." 

 green, yellow, and red to about line " 0." 

 green and some yellow, 

 the spectrum from red end to about half- 

 way between " F " and " S." 

 from red to end of green about " F." 

 red with a touch of orange, 

 only red, 

 purple „ „ a little violet, a little yellow, orange, and 



red. 



Amm. sulph. of copper (blue) transmitted violet and blue only. 



Chloride of copper ... (green) „ green, an edging of blue, and faint 



yellow with an edging of orange. 



Saffron „ every thing except violet and blue. 



Pnchromate of potash (orange) „ red, orange, yellow, and very little 



green. 

 ,, I'^sry pa e 1 ^ ^^^^ orange, yellow, and green. 



Fuchsine (carmine) „ red only. 



Solution of carmine .. „ „ n 



Solution of iodine „ „ red, orange, and a very little-yellow. 



But though the ants so markedly avoided the violet glass, still, 

 as might be expected, the violet glass certainly had some effect, 

 because if it was put over the nest alone, the ants preferred being 

 under it to being under the plain glass only. 



I then compared the violet glass with a solution of ammonio- 

 siilphate of copper, which is very similar, though perhaps a little 

 more violet, and arranged the depth of the fluid so as to make it 

 as nearly as possible of the same depth of colour as the glass. 



