320 ARCH E. COLE 



The apparatus consisted of a bell jar (A) inserted in the jar B, which 

 was partially filled with water. Jar A was connected at its top with a 

 gas (commercial nitrogen or carbon dioxide) tank (D). Suspended 

 from the top of jar (A) were two wire baskets (C), containing yellow 

 phosphorus, which would remove any oxygen in the gas withdrawn 

 from the tank (D) and collected in jar (A) over the water in jar (B). 

 Pyrogallol could not be used to remove the oxygen on account of the 

 fact that carbon dioxide was used for some of the experiments. 



Samples of gas could be withdrawn from jar A into the collecting tube 

 F of a Hemple gas pipette (P) , which was used to measure the amount 

 of oxygen present. When the phosphorus had removed all the oxygen 

 from the gas in the jar A, the gas could then be led out through the 

 tube E, into the small bottle G. This bottle contained water in which 

 cuprous chloride was dissolved. The water took out phosphorus 

 pentoxide fumes, formed by the union of phosphorus and oxygen in 

 jar A, and the cuprous chloride took up any oxygen which the water 

 might contain, being changed in this process to cupric chloride. From 

 jar G the deoxygenated gas could be led through tube / into one side 

 of an H-shaped experimental chamber (K). The connection of the 

 two tubes of this chamber was about 1 cm. from the lower end. A 

 pocket was thus formed at the bottom of each tube. Tube J led from 

 the other side of the H-shaped chamber to the exterior and opened 

 beneath the surface of water, being thus sealed. 



The aqueous extract of the organism, and the indicator (guaiacum 

 or benzidine) could be placed in separate pockets of the chamber. 

 The deoxygenated gas could be then led through the chamber (rather 

 rapidly at first) which would wash out all the air. Later, the flow 

 could be decreased and continued for any desired length of time, thus 

 removing by diffusion any oxygen dissolved in either the extract or the 

 indicator. It was assumed that all the oxygen would be removed by 

 this method after a continuous flow of the deoxygenated gas of from 

 two to three hours. At the end of that time the chamber could be 

 tipped on a horizontal axis and the indicator poured into the solution 

 to be tested. In this way a reaction could be obtained in the absence 

 of molecular oxygen. 



In order that an aqueous extract of an organism could be made in 

 the absence of oxygen, the experimental tube was provided with a 

 grinding apparatus, which consisted of a glass pestle (N) working 

 through a stuffing box (0) at the upper end of the chamber against 

 small piece's of broken glass in the bottom of the tube. Extracts of 

 organisms could thus be made in any stage of an experiment. 



This same apparatus (fig. 2) was used in the experiments with plant 

 remains found in the mud at the bottom of the lake, except that the 

 experimental chamber was inclosed with a covering of black paper 

 which shut out the light and thus insured against the production of 

 oxygen by a photosynthetic process. 



