148 THE ROYAL SOCIETY OF CANADA 



organism. Seaweed and sea water are sufficient nutriment for 

 vigorous growth of the red organism and in all probability this microbe 

 is a sea water organism, which can adapt itself to growth in strong 

 brine, and resist for a considerable period dessication brought about 

 by evaporation of water under a tropical sun accompanied by warm 

 winds. 



On page 142 mention was made of the statement of a salt manu- 

 facturer in Turks Islands that in salt stored from three to six months 

 the red colour disappeared. Sterilized bottles were sent and samples 

 of salt were received from this manufacturer in May, 1922, one of 

 which was labelled ''old crystals, gathered in 1921," and another 

 ''old, old crystals, gathered in 1919-1920." Crystals from each of 

 these samples were transferred to the following media and incubated 

 at 37° C.:— 



A. 16 per cent, salt codfish agar. 



B. 16 per cent, brine with filter paper half in and half out of the 

 liquid. 



C. Codfish slopes in 16 per cent, brine. 



D. Halibut slopes in 16 per cent, brine. 



E. Irish moss in 14 per cent, brine, sterilized. 



F. Irish moss in 14 per cent, brine, not sterilized. 



After five weeks' incubation, at the above temperature, all tubes 

 were distinctly red. These results justify the conclusion that the 

 manufacturer's assertion is not warranted by the experimental 

 evidence, for even the oldest salt proved to be infected with the red 

 organism, which developed well on suitable media at optimum 

 temperature. 



Further, this experiment confirms our results on the viability 

 of the red organism, as shown by the long duration of life in old dried 

 out cultures (see page 133), and makes it necessary to take such 

 measures as will destroy the red organism in tropical salts. 



11. Remedial Measures. 



The most important point arising out of these experiments is the 

 fact that tropical or solar salts carry the red organism, and so long 

 as they are used in their present form red colouration of fish is bound 

 to follow. 



Curing establishments that use this salt, or have been using it, 

 have their tanks, floors, storage places, puncheons, kench racks, 

 carrying boxes, utensils, etc., impregnated or inoculated with the red 

 organism. 



