60 



MINNESOTA BOTANICAL STUDIES. 



Table III. 

 .4 cc. of ether in 3000 cc. of air. 

 .4 cc. of chloroform in 2000 cc. of air 

 .4 cc. of carbon bisulphide in 2000 cc. ot air. 

 I. cc. of alcohol in 2000 cc. of air. 

 .2 cc. of ammonia in 2000 cc. of air. 



I. 



II. 

 III. 

 IV. 



V. 

 VI. Control. 



From the above tables it will be seen that a very small amount 

 of carbon bisulphide or ammonia vapors is very injurious to 

 young seedlings, while ether, chloroform and alcohol vapors 

 in minute quantities are not injurious when the plant is not 

 subjected to their prolonged action. On the contrary, small 

 amounts of ether and chloroform vapors seem to accelerate 

 growth. 



3. The Influence of Gase.s and Vapors upon Growing 



Shoots. 



A. Gases. — Nitrous oxide and oxygen were used in these 

 experiments in the following quantities: 25 per cent., 50 per 

 cent, and 100 per cent. The plants were kept under the bell 

 jars for twenty days. 



