CHEMICAL CHANGES OCCURRING IN OYSTERS. 15 



They were then washed for about 5 minutes by means of water from 

 a 1^-inch hose, the oysters being constantly stirred about with a 

 wooden paddle. They were then drained and packed for shipment. 

 This represents regular commercial practice in this particular oyster- 

 house. 



Experiment 5. — This experiment was conducted in a plant which 

 uses the old method of washing, but in which the oysters are sub- 

 jected to the action of water in a tank, with occasional agitation by 

 means of a paddle, for 20 or 30 minutes, then drained upon a skim- 

 mer. Seven gallons of oysters were placed in the tank and treated 

 as already described. 



Experiment 7 . — This experiment was run in a tank, but, instead of 

 air agitation, the oysters were stirred constantly by means of a large 

 metal paddle. They were drained, measured, and replaced in the 

 tank at such intervals that the period of washing between measure- 

 ments was 10 minutes. Samples were taken before washing was 

 begun, and each time the oysters were measured. Washing was con- 

 tinued until the oysters began to lose markedly in volume, which 

 was observed after 50 minutes of washing. 



Experiment 8. — This experiment was conducted in the same man- 

 ner as Experiment 7, except that it was done in a different oyster- 

 house and that the regular air-agitation method was used. 



Experiment 9. — The object of this experiment was to determine 

 whether or not oysters lose appreciably in volume on account of 

 repeated handling and measurement as done in the preceding experi- 

 ments. Six gallons of drained oysters were placed in one tank and 

 washed for 30 minutes by the regular method, with air agitation. 

 Seven gallons of the same stock were washed in the adjoining tank 

 with air agitation, but were drained and measured at 10-minute 

 intervals, as in the foregoing experiment. 



Experiment 10. — Having shown that handling oysters during wash- 

 ing has a marked effect in decreasing the osmotic distention and 

 increasing the actual loss of substance, it was decided to run an 

 experiment to compare the volumes and chemical composition of 

 oysters washed and handled under conditions identical except for the 

 time of washing. This experiment was also designed to find out 

 what the maximum of osmotic distention would be. Five gallons 

 of drained oysters were placed in each of three adjoining tanks and 

 washed with the regular water current and air agitation, Tank A 

 for 30 minutes, Tank B for 60 minutes, and Tank C for 90 minutes. 

 A representative sample of the whole lot was taken before the wash- 

 ing was begun, and from each tank at the expiration of its period of 

 washing. 



Experiment 11. — This experiment was made under regular ship- 

 ping conditions, and was simply a measurement and analysis of 



