EFFECTS OF PULP MILL POLLUTION ON OYSTERS 
131 
chamber (A) separated from the larger one by a wall ( B ), 4.5 centimeters high. 
Baffle plates ( C and O'), approximately equally spaced, divided the chamber incom- 
pletely into several parts. Both sea water 
and liquor solution flowed into chamber A, 
where they were well mixed. The result- 
ing solution flowed over plate B and back 
and forth among the baffle plates, becom- 
ing thoroughly mixed, until it flowed out 
through the tube ( [D ) into the aqarium 
containing the experimental specimens. 
The rate of flow of sea water was fixed 
as shown in Figure 1. Through the tube 
( H) water continuously flowed more rap- 
idly than was necessary into the 10-gallon 
aquarium (/). A large constant-level si- 
phon (J) of celluloid, having a cross-section 
area of about 5 square centimeters, main- 
tained a constant level in the aquarium jar 
in spite of min or variations in the rate of flow of entering water. Glass and rubber 
tubes of 3 to 5 millimeters inside diameter led from the aquarium to the mixing 
chamber (fig. 1, G; fig 3, A) into which the liquor was dripping. 
The experimental and control specimens were contained in 
a tank (fig. 4) consisting of three separate but adjoining compart- 
ments {A, B, O), each having a capacity of about three liters. In 
the front wall of each compartment an overflow space ( D ) was 
cut to allow continuous overflow without passing of the fluids from 
one chamber into another. A tube from a mixing chamber led 
to each of the two end compartments, while another tube led 
from the aquarium jar (fig. 1, I) into the middle compartment. 
The two end chambers contained running mixtures of sea water 
and sulphite liquor in known proportions, while the middle cham- 
ber contained pure, running sea water as a control. 
Fresh oysters were mounted on a plaster of Paris base to 
hold them in a fixed position and at the same time not interfere 
with their natural functions. Two such specimens were placed 
in each of the three experimental compartments. (Fig. 4, A, B, C.) 
Records of the shell movements were kept continuously by 
means of a kymograph. A slender strip of celluloid (fig. 4, E) 
rested upon the shell of each specimen and was movably attached 
at its upper end to a horizontal celluloid lever ( F ). A short wire 
nuiiita o. — juiagiam ui . . 
the mixing chamber at the distal end oi the lever came into contact with the smoked, 
water 1 ’ and Sulphite slowly moving kymograph paper. All six specimens of a series 
oughly mSed before were arranged to write their records on the same paper, 
entering the aquaria. The kymograph carried a paper about 2 meters long and 
see deenptionm text movec i a t a constant rate of about 31 millimeters per hour. Usu- 
ally after the paper had made a complete circuit the drum was slightly lifted and 
another circuit made, the levers writing in between the lines made the first time. 
66424—31 2 
A 8 
3 
\ uL 
\ • 
/ 
\ 
c 1 
i • 
/ 
w 
1 
e 
J 
) 
Figure 2. — Diagram of the dripping chamber from which 
liquor dripped at a constant rate into the mixing cham- 
ber. See text for full description 
