1908] CROCKER AND KNIGHT—CARNATIONS 275 
contains, it does not follow that such is the case with all parts of 
plants or even with the flowers of all plants. It would be interesting 
to know the effects and toxic limits of illuminating gas and its con- 
stituents upon various double as well as single flowers. Similar 
data for the foliage of various plants such as Coleus, which is supposed 
to be especially sensitive to illuminating gas, would likewise be of 
interest, 
5. Summary 
1. The flowers of the carnation are extremely sensitive to traces 
of illuminating gas in the air. 
2. With the Boston Market and pink Lawson three days’ Papeete 
'0 1 part in 40,000 kills the young buds and prevents the opening 
of those already showing the petals. The buds of medium age are 
considerably more resistant. 
3- In the same varieties 1 part in 80,000 causes the closing of the 
open flowers upon twelve hours’ exposure. 
4. This injury takes place directly on the bud or flower exposed 
and not indirectly through absorption by the roots. 
5- No chemical test is delicate enough to detect the least trace 
of illuminating gas that will cause serious injury to carnations. 
6. The “sleep” of the carnation is probably often caused by traces 
of illuminating gas in the air. F 
7- Ethylene is even more fatal to the flowers of the carnation. 
_ 8. Three days’ exposure to 1 part in 1,000,000 prevents the open- 
ng of buds just showing the petals. : 
9. Twelve hours’ exposure to 1 part in 2,000,000 causes the closing 
of flowers already open. ; 
‘S. There is much evidence that indicates that the toxic limit of 
inating 8as upon these flowers is determined by the ethylene it 
Contains, 
THE University oF CHICAGO 
LITERATURE CITED 
 GIRARDIN, —, Einfluss des Leuchtgases auf die Promenaden und Strassen- 
- Jahresber, Agrikultur. '7:199-200. 1864. Ss 
: Vincuow, R., Einfluss des Leuchtgases auf die Baumvegetation. Jahresber. 
Agrikultur, 13-15:237. 1870-72. 
