Sandsten : INFLUENCE OF GASES AXD VAPORS UPON GROWTH. 



63 



TABLE V. 



I. 20 per cent, of gas. 



II. 50 per cent, of gas. 



III. 100 per cent, of gas. 



IV. Control. 



a. Nitrous oxide. 



b. Oxygen. 



Exposed to gas ten days. 



It is to be regretted that the root system could not be meas- 

 ured and examined during the experiments without injuring the 

 plants to such an extent as to make the experiment useless. 

 The table does not show anything in favor of the plants treated. 

 The only conclusion that can be drawn is that these gases have 

 no perceptible influence on Narcissus bulbs. 



Ammonia. Vapors of this reagent are not injurious to the 

 resting bulb when the amount of vapor present does not exceed 

 one part in 5000 of air. Ariscema trtphyllum, Narcissus, Cro- 

 cus, Freesia and Tulip bulbs were exposed to an atmosphere 

 containing one part of ammonia in 5000 of air for ten days 

 without injuring the growing qualities of the bulb. 



