424 
BULLETIN OF BUREAU OF FISHERIES 
Ferrous sulphate, FeS 04 . Green vitriol or copperas 
Waters from mines containing pyrites; in pickle liquor from industrial plants cleaning iron plate 
or wire. Weigelt, Saare, and Schwab (1885), 2,721 p. p. m. in tap water killed trout and California 
salmon in 31-66 minutes; Clark and Adams (1913), 2.9 p. p. m. in distilled water killed shiners, 
carp, and suckers in 4-24 hours; Carpenter (1927), 315 p. p. in. in distilled water killed minnows, 
Leuciscus phoxinus, in about 3 hours; M. M. E., 1,000 p. p. m. in hard water killed goldfish, Car 
assius auratus, in 2-10 hours, 100 p. p. m. in hard water apparently not harmful to goldfish in a 
96-hour exposure. 
Gallic acid, C 6 H 2 (COOH)(QH) 3 
Dye wastes; tannery wastes; some chemical wastes. Penny and Adams (1863), 143 p. p. m 
killed goldfish and minnows. 
Glycerol, (CH,OH) 2 CHOH. Glycerine 
Soap factories. Weigelt, Saare, and Schwab (1885), tench survived 16-hour exposure at 8° C. 
to 100,000 p. p. m. in tap water without apparent effect. 
Hydrochloric acid, HC1. Muriatic acid 
In effluents from many chemical processes. Weigelt, Saare, and Schwab (1885), 1,000 p. p. m. 
in tap water caused trout to overturn helpless in 2-5 minutes; Wells (1915a), 3.6 p. p. m. in distilled 
water killed green sunfish, Lepomis cyanellus , in 48 hours. Standing Committee on Rivers Pollu- 
tion (1924), 200 p. p. m. in distilled water produced general collapse in perch and roach; M. M. E., 
166 p. p. m. in hard water killed goldfish, Carassius auratus, in 4-7 hours; 157 p. p. m. in hard water 
apparently did not injure goldfish in over 100 hours’ exposure; 56 p. p. m. in soft water killed clado- 
cerans, Daphnia magna, in 17—72 hours. 
Hydrogen sulphide, H 2 S 
Produced by decomposition of many types of organic effluents, both municipal and industrial, 
and occurs in many trade wastes, chemical wastes, and gas wastes. This gas which readily dis- 
solves in Water is not only harmful in itself but in its decomposition may produce colloidal sulphur, 
which is also a pollution hazard. Weigelt, Saare, and Schwab (1885), a 3-hour exposure to 100 
p. p. m. in tap water was fatal to tench, Tinea vulgaris, 8 days later, and 10 p. p. m. in tap water 
caused trout to float on back in 15 minutes; Shelford (1917), 4. 9-5. 3 p. p. m. in tap water killed 
orange-spotted sunfish, Lepomis humilis, in 1 hour; Belding (1929), 0.086 p. p. m. lethal for brook 
trout, Salvelinus fontinalis, 3.8 p. p. m. for the sucker, Catostomus commersonii, 4.3 p. p. m. for 
aquarium goldfish, Carassius auratus, and 6.3 p. p. m. for carp, Cyprinus carpio; M. M. E., 10 
p. p. m. in hard water killed goldfish, Carassius auratus, in 96 hours or less, 5 p. p. m. killed some 
goldfish in 200 hours, and 1 p. p. m. in soft water killed cladocerans, Daphnia magna, in 72 hours or 
less. 
Iodine, I 2 
Rarely found free in stream water, 
and goldfish. 
Penny and Adams (1863), 28.5 p. p. m. killed minnows 
Iron, Fe 2 
See various ferric and ferrous compounds. 
Lactic acid, CH 3 CH(OH)COOH 
A component of various dairy industries wastes. M. M. E., 654 p. p. m., in hard water killed 
goldfish, Carassius auratus, in 6-43 hours, but 430 p. p. m. in hard water apparently was not harmful 
to goldfish in exposures of over 100 hours; 170 p. p. m. in soft water killed cladocerans, Dapghnia 
magna, in 26-72 hours. 
Lead, Pb 2 
Compounds of this metal are found in many industrial wastes and in effluents from various 
mining and ore milling operations. These compounds are highly toxic as has been discussed under 
