STREAM POLLUTION 
415 
Table 11. — Survivals of 850 goldfish in various concentrations of salts of 8 metals found in industrial 
wastes 1 — Continued 
Specific con- 
pH 
ductivity 
Concen- 
Parts 
mhoXlO-* 
Substance 
tration 
per 
Diluent 
at, zo 
Ay. 
Survival time 1 
Constituent of— 
ratio by 
weight 
mil- 
water 
lion 
Water 
Solu- 
tion 
Water 
Solu- 
tion 
3 1:1.000 
1, 000 
do 
7.7 
6.4 
594 
1,307 
2 to 10 hours 
Do 
3 1:10,000 
3 1:100,000 
3 1:1, 000, 000 
1:1,000 
1:10,000 
100 
do 
7. 7 
6.7 
594 
649 
OO 
Do 
10 
...do 
7. 7 
7.4 
594 
598 
CO 
Do 
1 
...do 
7.7 
7.6 
594 
600 
CO 
Wire and tin- 
plate mills 
wastes. 
Ferric chloride 
Do 
1,000 
100 
Very soft.. . . 
do 
6.2 
6.2 
2. 4 
3.4 
<50 
<50 
2, 156 
334 
1 hour to 1 hour 10 
minutes. 
1 hour to 1 hour 20 
minutes. 
Do 
1:10, 000 
1:100, 000 
3 1:1,000 
100 
Hard 
7.8 
5.5 
647 
700 
00 
Do. 
10 
Very soft... . 
6.2 
5.0 
<50 
678 
<50 
00 
1,000 
100 
Hard 
7.8 
6.4 
2, 500 
2 to 3 hours 
Mining and 
■ smelting 
wastes. 
Do 
3 1:10,000 
3 1:100, 000 
do 
7.8 
6.8 
678 
775 
80 hours to “> 
Do 
10 
1 
.. do 
7.8 
7. 4 
678 
678 
CO 
Do 
3 1:1, 000, 000 
1:1,000 
...do 
7.8 
7.5 
678 
673 
CD 
Nickelous chloride 
1,000 
Very soft.. 
6.3 
6.3 
<50 
1,876 
6 hours to 18 hours 
30 minutes. 
Do 
1:1,000 
1,000 
100 
Hard 
7.8 
7.4 
647 
2, 218 
253 
12 to 18 hours 
Electroplating 
wastes. 
Do... 
1:10,000 
Very soft 
6.3 
6.3 
<50 
19 hours 25 minutes 
to 50 hours 25 min- 
utes. 
Do 
1:100.000 
10 
do 
6.5 
6.5 
<50 
95 
200 to 210 hours 
1: 1, 000 
1, 000 
Very soft 
6. 4 
3. 5 
<50 
647 
2, 380 
1 hour to 1 hour 30 
Brass industries 
wastes. 
Do. 
1:1,000 
1,000 
1,000 
100 
Hard 
7.8 
3.8 
1,609 
1,538 
780 
minutes. 
4 to 5 hours 
3 1:1,000 
do 
7.8 
7.2 
678 
1 to 4 hours 
Mining and 
smelting 
wastes. 
Do 
3 1:10,000 
3 1:100,000 
3 1:1, 000, 000 
do 
7.8 
7.6 
678 
Do 
10 
do 
7.8 
7.6 
678 
678 
CO 
Do.. _ 
1 
do 
7.8 
7.6 
678 
678 
CD 
1 Experimental conditions as in table 8. 
3 Minimal and maximal survival times as found in these experiments. Infinity sign indicates survival greater than 4 days 
without any apparent injury to the fish. 
3 Initial volume of 3 liters per fish replaced by constant flow apparatus at rate of 1 liter per hour. 
Another hazard from wastes containing compounds of various metals is the 
cumulative effect. Even though precipitated out, compounds carrying these metals, 
as long as they remain in the stream, on the bank, or on the floor of the stream, are 
subject to re-solution if conditions in the waters change (in many cases only slightly), 
and to ingestion by fish and other aquatic animals during feeding. 
The case of lead salts will suffice for example. Carpenter in a series of papers 
(1924, 1925, 1926, 1927, and 1930) has shown that the lethal action of lead compounds 
on fishes in cases where the more soluble lead salts are present is due to the precipita- 
tion of mucus and proteins in and on the gills by the lead ion, and that the absorption 
and, therefore, the internal poisoning of fishes by lead compounds under these condi- 
tions is negligible during moderately short exposures. This conclusion has been con- 
firmed by Behrens (1925) using a very delicate test (the radio-activity of an isotope 
of lead) which demonstrated the distribution of lead throughout the body of the fish. 
However, the writer in long-time experiments in which goldfish were kept in 
glass containers, the bottoms of which were covered with finely powdered lead ore 
(lead sulphide, which is very insoluble in water), found cumulative effects which 
resulted in the death of fish after 61 days of such exposure, although there were no 
casualties in the controls carried under identical conditions except for the presence 
of lead ore. Although these experiments which are being followed further do not in 
themselves prove that the cumulative action was that of lead alone or of lead in con- 
junction with some other substance (i. e., traces of other substances in the ore may 
