McKeniiey — Oyi Luminous Bacteria. 223 



The Effect of Ether. 



One c.c. of ether added to a luminous culture of Bacillus phosphor es- 

 rfiis at once destroys luminescence. This elfect is, however, as much 

 physical as physiological, for the ether spreads as a thin film over the 

 surface of the culture and excludes free oxygen. 



To ascertain the physiological etfoct of the ether, it was used both in 

 water solution and in vapor form. To good luminous bouillon cultures 

 10^ ether water was added in suflicient amount to make \'/c ether in the 

 culture. In all such cases the light was at once extinguished. After 2 

 to 3 hours, however, the cultures were as brightly luminous as ever. 

 When 5^ ether water is added in sufHcient amount to have .5^ ether in 

 the culture, luminescence does not cease or only after from 30 to 15 

 minutes and then the culture rarely remains dark for about an 

 hour. The light return is in all probability due to the evaporation of 

 the ether. While .5^^ of ether in the culture may then at times cause 

 narcosis, as much as Ifo is to be considered as about the minimum 

 amount needed to regularly produce narcosis. 



In order to determine whether all or only some of the activities of the 

 organism were held in abeyance, the eflfect of the prolonged action of 

 ether was investigated. To good luminous cultures 5^ other water was 

 added in sufficient amount to make .5^ ether in the culture. The cul- 

 ture thus treated was placed together with an open dish of 5^ ether 

 water under a large bell-jar. The size of the bell-glass insured a suf- 

 ficient quantity of free oxj'gen and at the same time retained the ether 

 vapor. In the course of 15 to 35 minutes light was no longer evident in 

 the cultures and they remained dark while under observation which 

 lasted, in some cases 3 days, in others 1 week. The growth in the cul- 

 tures was meanwhile luxuriant. It is noteworthy however, that a sur- 

 face film was rarely formed and that the growth was quite evenly dis- 

 tributed throughout the liquid medium. Further the red discoloration 

 and consequent rich production of the lower fatty acids, appeared much 

 later than in untreated cultures. Usually the red color and the fatty 

 acids appeared in from 4 to 5 days after inoculation. In the cultures 

 thus treated with ether this condition did not appear until 1 week or 

 10 days after inoculation. 



Since the photobacteria showed themselves capable of some adaptation 

 to high temperatures, the thought occured that perhaps there might be 

 a similar adaptability to ether. From cultures which had been exposed 

 to the effects of ether as above described for 24 hours, transfers were 

 made to fresh media [B) and to these 5 cultures .ofc ether added and the 

 daughter cultures placed with the parents under the bell-glass together 

 with the open dish of ether water. The growth in the B cultures was 

 luxuriant but no light was produced. After 24 hours growth of the B 

 cultures under ether influence, transfers were made to a third set (C) of 

 media. The growth in C cultures was good and after 24 hours the cul- 

 tures were markedly luminescent. Transfers were made to a further 

 set (D) of media and these too in 24 hours exhibited not only luxuriant 



