[Vol. 2 



534 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



Crocker and Knight ('08), in their work on the question of 

 injury by illuminating gas ami its constituents, concluded that 

 " there is much evidence that indicates that the toxic limits of 

 illuminating gas upon these flowers [carnations] is determined 

 by the ethylene it contains." They used a small greenhouse 

 of 1.69 cubic meters' capacity in which they placed potted 

 plants for varying intervals, specified amounts of gas being 

 introduced. The buds were easily injured but the vegetation 

 was apparently not affected even after an exposure of about 

 72 hours, during which 10 liters of gas had been introduced, 2 

 or 4 liters at a time. The method was therefore somewhat 

 different from the one employed by the author, in which the 

 plants were placed in an atmosphere saturated with illuminat- 

 ing gas, but for a much shorter period. The underlying cause 

 of the effect in both cases, however, is probably the same. 



The etherization of plants as a practical process has been in 

 operation for many decades, especially as a means of hasten- 

 ing the activities of plants, particularly of bringing them into 

 bloom earlier. Some experimental work has also been done, as 

 we have seen, on the effect of such treatment (though in most 

 cases only when the anesthetics were in solution) upon the 

 exosmosis of non-electrolytes, as determined by various 

 methods, from plant or animal cells. It is interesting, there- 

 fore, to observe the exosmotic phenomena of electrolytes when 

 the plants are anesthetized under various conditions. 



To determine whether the amount of substance excreted cor- 

 responded to the conductivity readings, the water in the turn- 

 biers was evaporated and the residue weighed. The following 

 are the results : 



Total wt. of substance from illuminating gas-treated 



cultures (Nos. 33, 35, 37, 39, 41, and 43) 0.1514 grams 



Total wt. of substance from ether-treated cultures (Nos. 



45, 47, 49, 51, 53, and 55) 0.0674 grams 



Total wt. of substance from the 12 controls 0.1077 grams 



Total wt. of substance from G controls, therefore 0.0538 grams 



We may obtain a rough basis for estimating this residue in 

 terms of NaCl by comparing the figures just given with the 

 data on a previous page which gave the corresponding spe- 

 cific conductivitv values for some values of x on the Wheat- 



