







iq2o] LANGDON & GAILEY— CARBON MONOXIDE 235 



The appearance of C0 2 and the lowering of the oxygen content 

 when the unmutilated plants were kept in the dark for some time 

 were shown by the following experiments. Twelve whole plants 

 were gathered from the same bed, precaution being taken to avoid 

 in any way disrupting the gas cavity. The gas from 6 of them 

 was analyzed at once and showed an average of 15 per cent of 

 oxygen, 3 . 2 per cent of carbon monoxide, and no carbon dioxide. 

 The other 6 plants were placed intact in the dark boxes, and after 

 being anchored out in the tidal currents for 6 days showed the 

 following average gas composition: oxygen 4.7 per cent, carbon 

 monoxide 2.9 per cent, and carbon dioxide 0.5 per cent. There 

 was therefore a marked decrease in the oxygen content, and an 

 appearance of carbon dioxide which is practically never present 

 in the kelp when freshly collected, while there was practically 

 the same carbon monoxide content. 



The substitution of gases other than air for those normally 

 present was next undertaken. As a result of more than 40 care- 

 fully made experiments, in which nitrogen was substituted for the 



* 



kelp gas, it can be stated confidently that no carbon monoxide was 

 formed, either in the light or in the dark, either when fronds were 

 present or when they had been removed, or at any intermediate 

 time between the initial filling and the 8-10 days before decay had 

 become so pronounced that observations could no longer be made. 

 It should be remarked that a small percentage of carbon dioxide 

 was generally formed, even though there was no oxygen present. 



The nitrogen was prepared in three ways. One method was 

 by heating a mixture of concentrated aqueous solution of sodium 

 nitrite and ammonium chloride. The products other than nitro- 

 gen from this reaction are sodium chloride and water. The first 

 few liters of gas evolved were discarded and the remainder showed 

 no oxygen. The gas was washed through strong sodium hydroxide 

 solution. The second method of preparing ik nitrogen" was to 

 absorb the oxygen from the air by means of alkaline pyrogallol. 

 That the failure of the plant to produce carbon monoxide was not 

 due to a trace of some unknown impurity, introduced into the 

 nitrogen as chemically prepared and purified, was made certain by 

 the use of nitrogen obtained by the fractional distillation of liquid 





