Method. — A small quantity of wheat that had been 

 soaked in water for about twelve hours was sealed in a bottle 

 containing C0 2 gas. The method of charging the bottle with 

 C0 2 was the same as that employed in Experiment 4. 



Result. — The grain failed to germinate, but swelled to 

 an unusual size before it died. 



Inference. — Germinating wheat is asphyxiated by C0 2 

 because of the absence of chlorophyll in the plumule. 



Experiment 8. — To demonstrate the effects of an atmo- 

 sphere of nitrogen upon wet wheat. 



Method. — The apparatus and methods employed were 

 similar to those outlined in Experiment 5. In this instance 

 soaked wheat was used instead of dry grain. 



Result. — Germination proceeded slightly, just sufficient 

 to show the development of the radicle and plumule. Growth 

 ceased abruptly and the grain died. No chlorophyll was 

 formed in the plumule. 



Inference. — Free oxygen is essential to the development 

 of a germinating seed, and also to the development of 

 chlorophyll. 



Simple Method of Testing Air-tight Bottles. 



Completely immerse the sealed bottle in water that is 

 a little warmer than the atmosphere. The air within the 

 bottle expands, and should the bottle leak, silvery-looking 

 air-bubbles will mark the position of the aperture. 



Concluding Remarks. 



1. Vermin may be destroyed in properly-enclosed wheat 

 stacks by the use of C0 2 or nitrogen gas without damage to 

 the germinating qualities of the grain. 



2. Perfectly ripe, dry grain can be safely stored from 

 harvest time until the time for seeding in an atmosphere rich 

 in C0 2 gas. 



3. Excess of C0 2 gas and nitrogen prevents the develop- 

 ment of weevil from eggs within a properly-heated stack. 



4. Any ordinary barn properly lined with asbestos sheets 

 will serve as a suitable storehouse or gas-envelope. 



5. The C0 2 gas- can be generated by pouring dilute 

 hydrochloric acid on chips of marble or limestone. 



6. The gas should be introduced near the top at one end 

 of the stack, and the outlet pipe for- the displaced air should 

 be inserted near the bottom of the stack at the other end. 



7. The escaping air should be tested with a little lime- 

 water. When the escaping air causes the lime-water to turn 



