16 BULLETIN 740, U. S. DEPARTMENT OF AGRICULTURE. 



oysters before and after washing with the regular water current and 

 air agitation for 30 minutes. 



Experiment 12. — This experiment is of the same nature as the 

 preceding one, simply measurement and analysis of a commercial 

 shipment before and after washing with regular water current and 

 air agitation. 



Experiment 13. — This experiment was carried out in the same 

 manner as was Experiment 12, except that enough dairy salt was 

 added to the wash water to make the salinity of the solution 2.53 

 per cent. The water over the beds where the oysters were grown 

 varied from 2.48 to 2.70 per cent salinity, so no osmosis should take 

 place. The object of this experiment was to test the correctness of 

 the belief commonly held that all the salt must be washed out of 

 oysters to have them "keep." It has been observed since the 

 beginning of the industry that oysters tended to spoil if the salt was 

 not washed out to below the point where it could be tasted in the 

 water; hence the spoiling was connected with the salinity. This 

 phenomenon appears to be merely a coincidence, due to the fact 

 that the putrefactive bacteria are washed out at about the same rate 

 as is the salt. 



Experiment 14- — The oysters in this experiment were washed upon 

 a skimmer with a hose for 10 minutes, and were stirred constantly 

 with a paddle. 



Experiment 15. — In this experiment the oysters were washed in a 

 regular agitation tank by the regular method, except that instead of 

 being constantly agitated by a current of air they were stirred every 

 5 minutes with a large metal paddle. Thus, the oysters were affected 

 by a constant stream of cold water from the bottom of the tank, and 

 were thoroughly agitated six times during the experiment. 



