140 
BULLETIN OF THE BUREAU OF FISHERIES 
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o O SPECIMEN *5 
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A- —A SPECIMEN *6 
• or ▲ DEAD 
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3 6 7 8 9 10 
20 21 22 23 24 23 26 
-Graph showing the records of the two specimens in experiment No. 20 
(2 parts per 1,000). Compare records of controls (fig. 16) 
Experiment No. 20 ( 2.0 parts per thousand). — The rate of flow of water was 124 
cubic centimeters per minute and that of liquor solution (1 : 9) 2.5 cubic centimeters 
per minute. The pH of the solution in the experimental chamber was from 6.8 to 
7.2. Liquor was started dripping into the mixing chamber on February 28 at 12.30 
p. m. On the preceding two days both specimens were open most of the time, but 
after the liquor was started both remained closed more and more of the time until 
finally they gaped open 
and steadily ceased activ- 
ity. (Fig. 17.) Specimen 
No. 5 averaged, from 
March 1 to 15, when it 
started gaping, 12.93 hours 
per day open and was 
finally dead on the 25th, 
following 24 days of treat- 
ment with the solution. 
Specimen No. 6 also died 
after 24 days of treatment 
and during the period from March 1 to 20 remained open an average of only 9.9 hours 
per day. Compare the records of the two control specimens. (Fig. 16.) 
Experiments Nos. 22 and 23 {March 12 to April 11, 1930). — During this series 
the temperature of the water was 14° to 17° C., except for certain short intervals 
when the heater was out of order, until April 1 when it was no longer heated and the 
temperature varied from 8° to 12° C. The pH of the water was 7.7 to 7.9. The stock 
liquor solution consisted of 1 part pure liquor to 9 parts sea water. 
Experiment No. 23 
(0.67 parts per thou- 
sand.) — Water entered 
the mixing chamber at 
the rate of 136 cubic 
centimeters per min- 
ute, and liquor solution 
(1 : 9) at the rate of 
0.9 cubic centimeters 
per minute. The pH 
of the solution in the ex- 
perimental tank varied 
from 7.1 to 7.5. 
Both specimens Nos. 1 and 2 (fig. 18) were open about 23 hours per day before 
liquor was started dripping into the mixing chamber on March 13 at 10.30 a. m. 
Then both oysters showed marked disturbances. From March 14 until April 2 
specimen No. 1 averaged 16.21 hours per day open. From April 3 to 10 the specimen 
was gaping wide and making infrequent movements, at the end of which time death 
occurred after 28 days of treatment. Specimen No. 2 did not die during the period 
of the experiment, but averaged only 14.49 hours per day open from March 14 to 
April 11, during the 29 days of treatment. 
The control specimens behaved in a strikingly different manner. (Fig. 19.) 
From March 14 until the experiment was stopped (29 days) specimen No. 3 was 
Figure 18— Graph of records of specimens in experiment No. 23 (0.67 part per 1,000). 
There is considerable fluctuation in the curves, and only one of the specimens died 
before the test was discontinued. Compare with the records of the control oysters 
