3io 



E. NEWTON HARVEY. 



TABLE III. 



EFFECT OF VARIOUS COMBINATIONS OF THE SALTS OF SEA WATER. 



The most interesting point brought out in the above table is 

 the independence of these bacteria of a balanced medium. The 

 bacteria live and phosphoresce in pure NaCl without the addition 

 of any bivalent ions. This is true even when the solution is 

 changed three times to remove the last traces of Ca in the bacteria. 

 KC1 is also relatively non-toxic, although more so that NaCl. 

 CaCl2 and MgCl2 are very toxic when alone. All combinations 

 of NaCl with the other ions of sea water sustain the bacteria well 

 except that they are neutral media and hence the phosphorescence 

 is dimmed after 24 hours. That pure NaCl should have so little 

 effect on light production is astonishing when we consider its 

 poisonous effect on other marine organisms and tissues, partic- 

 ularly on ciliated cells. 



The effect of the alcohols (Table IV.) on light production is very 

 similar to their effect on other life processes: they exert an inhibit- 

 ing or anaesthetic action which is perfectly reversible. If alcohol 

 solutions containing bacteria which have stopped emitting light 

 are diluted with sea water, light production again begins. As 

 with other tissues the higher the alcohol in the series the greater 

 anaesthetic power it has. 



The effect of a number of other substances was studied in a 

 very rough way namely, by adding a small quantity of the 

 substance to a sea water emulsion of the bacteria in test tubes 

 and then shaking the tubes. With toluol, benzol, ether, chloro- 

 form, carbon disulphide, carbon tetrachloride and ethyl butyrate 



