2 1 8 Pennington — A Chemico-PJiysiological 



The air current was maintained steadily for three weeks. 

 At the expiration of this time the absorption bulb was 

 removed, the acid transferred to a round-bottomed flask, 

 rendered alkaline with potassium hydrate, and distilled. 

 The volatilized substances were collected in a large quan- 

 tity of distilled water which was afterward examined for 

 trimethylamine, and also for ammonia, but none could be 

 found. This experiment was repeated three times, and in 

 no case did the amine result. From one experiment the 

 culture solution was poured off through a filter, then dis- 

 tilled, in order to determine whether the amine remained 

 dissolved in the water in spite of the air current. The 

 result was the same — no amine was present. 



Having proved that trimethylamine is not given off from 

 the cells when they are exposed to light, the next step was 

 to determine whether it is given off if the plant be kept in 

 darkness. 



Accordingly the culture flask was covered by an opaque 

 screen and the gas collected as before. At the expiration 

 of twenty-four hours the plant was de-starched. This cul- 

 ture, starch free, remained in good condition, so far as the 

 morphology of the cells indicated, for seven days. At the 

 end of this time the absorption bulb was removed, its con- 

 tents made alkaline and distilled as before. The method 

 used for the separation and estimation of this amine was 

 that described by Fleck,* which is based upon the solubility 

 of trimethylamine sulphate in cold absolute alcohol, ammo- 

 nium sulphate being under such conditions perfectly insolu- 

 ble. The amine is weighed in the form of its sulphate 

 (CH 3 ) 3 N. H 2 S0 4 . 



From the culture solution which had been maintained in 

 darkness, very appreciable quantities of the amine were 

 obtained, and the merest trace of ammonia. 



It was mentioned above that trimethylamine began to 

 come off almost immediately upon removing the plant 

 from water, and that it was completely expelled by drying 

 * Journ. Am. Chem. Soc, Vol. i8, p. 670. 



