266 BOTANICAL GAZETTE [october 



up the experiment the cork is placed on the stem of the carnation by 

 opening the cork at the split and inserting the stem. The flower or 

 bud and the long tube are put into the nozzle of the bottle and the 

 cork forced in until the whole apparatus is air-tight. The free end of 

 the calcium chlorid tube is placed into a dish (h) of water or (with 

 gases highly soluble in water) mercury; both pinchcocks (e and g) 

 are opened; and suction applied to the tube / until the liquid rises 

 to the small portion of the calcium chlorid tube, at which time pinch- 

 cock g is closed. The desired quantity of gas which is now poured 

 into the wide end of the calcium chlorid tube rises to the top of the 

 liquid. A one-holed rubber stopper, furnished with a tube and 

 attached to a column of the same liquid as is contained in the dish, 

 is now inserted into the free end of the calcium chlorid tube (d), and 

 the pressure of the column allowed to force the liquid to the inner end 

 of the long tube. This forces the gas into the end of the bottle 

 farthest from the flower and allows a gradual distribution by diffu- 

 sion. For ethylene and illuminating gas water was always used as 

 the forcing liquid. 



In determining the toxic limits of illuminating gas and ethylene, 

 20-liter carboys were used; while smaller bottles were employed in 

 some of the earlier experiments with these gases, as well as with all 

 the determinations of the least toxic gases. The question of the 

 effect of corking a bud or flower in a closed chamber of this kind 

 naturally arises, and suggests a criticism upon the method. It was 

 found that flowers opened without any apparent injury when corked 

 in flasks of only one liter capacity. In all checks and in all cases 

 where the concentration of the injurious gas was below the toxic limit, 

 the flowers bloomed normally while yet in the bottles. To avoid 

 undue rise of temperature within the chambers basket-covered car- 

 boys were used. The experiments were carried on in the laboratory 

 greenhouse during the months of May to September. The tempera- 

 ture in the experiments reported varied from 2o°-28°, and within this 

 range no noticeable variation in toxicity appeared. 



Two varieties of carnations were used — the Boston Market and 

 the pink Lawson. The two varieties vary so little in their sensitive- 

 ness and reaction to ethylene and illuminating gas that a description 

 of the responses of one applies equally well to the other. 



