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1920] LAXGDON 6- GAILEY—CARBOX MOXOXIDE 237 



stipe were not put back in their normal habitat, sea water, but 

 were left out in the air. It should be recalled that this plant will 

 withstand a very considerable amount of desiccation and will 

 resume growth when returned to the sea. Sections of stipe filled 

 with air and placed in a warm, dry, dimly lighted attic developed 

 0.7-4.7 per cent of carbon monoxide in 5 days. The oxygen con- 

 tent lowered to about 4 per cent and there appeared 1-2 per cent 

 of carbon dioxide. Similar results were obtained when specimens 

 of air-filled kelp were placed in good daylight (not direct sunlight) 

 or when kept exposed to the air in a dark room. Kelp filled with 

 nitrogen or with hydrogen and allowed to stand (dry) in the air 

 developed no carbon monoxide. On the other hand, under the 

 same conditions, but filled with mixtures of oxygen and hydrogen, 

 or oxygen and nitrogen, carbon monoxide was produced within a 

 few days. 



That carbon monoxide was not formed in dead kelp was shown 

 in the following manner. A number of plants were killed by being 

 placed for 10 minutes in sea water which was maintained at a 

 temperature of 50 C. The stipes, full of air, were corked. Some 

 of them were placed in the sea water in the light and some anchored 

 out in the dark boxes. Another set similarly treated was placed 

 in air, some of them in the light and the remainder in the dark. 

 Analysis of the gas from the various specimens 6 days later showed 

 no carbon monoxide. There had been a slight decrease in the 

 i oxygen content and the formation of 2 or 3 per cent of carbon 



dioxide. Exactly similar results were obtained when the kelp was 

 ' killed by being placed in N/50 Cu S0 4 for 18 hours. 



A series of experiments was started to determine what would 

 happen if kelp were filled with oxygen-free nitrogen or hydrogen 

 to which had been added a small quantity of carbon monoxide. 

 These experiments were not completed, but it became clear that 

 the change, if any, was slight. 



Nereocystis Luetkeana seems to be remarkably well adapted to 

 research on gas exchange of living cells. By the use of the very 

 refined methods of gas analysis which are now available, some 

 very interesting and valuable information might be gained. It is 

 possible that traces of hydrogen or carbon monoxide not revealed 



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