STREAM POLLUTION 
423 
Cresylic acid, a mixture of isomeric cresols and xylenols 
Mine floatation wastes; sheep and cattle dips. M. M. E., 0.1 p. p. m. in hard water killed gold- 
fish, Carassius auratus, in 5 days and 1 p. p. m. in 6-48 hours; 0.1 p. p. m. in soft water killed 
cladocerans Daphnia magna, in 72 hours. 
Cupric chloride, CuCl2 
Powers (1917), 0.0188 p. p. m. in distilled water killed goldfish in 3 hours 30 minutes to 7 hours; 
Carpenter (1927), 672 p. p. m. in distilled water killed the minnow, Leuciscus phoxinus, in 82 minutes. 
Cupric nitrate, Cu(N03)2 
Dilling and Healey (1926), 0.0188 p. p. m. in tap water killed many tadpoles and interfered 
with the development of those which survived. 
Cupric sulphate, CuSOi. Blue vitriol 
Because of the wide use of this compound in both industry and in aquatic investigations, and 
because of the variation in limits of lethality copper sulphate as given by many writers, owing to 
differences in water, in carbonate content, and in associated substances, a larger number of refer- 
ences have been included for copper sulphate than for most compounds in this list. Penny and 
Adams (1863), 10 p. p. m. fatal to goldfish and minnows, but 5 p. p. m. under the conditions of their 
tests were not lethal to these fishes; Moore and Kellerman (1905), 0.143 p. p. m. in hatchery water 
(Cold Spring Harbor, N. Y.), maximum strength tolerated by brook trout, and 0.33 p. p. m. maxi- 
mum for carp and suckers, 0.4 p. p. m. for catfish, 0.5 p.p. m. for goldfish, 1.33 p.p. m. for sunfish, 2 p. p. m. 
for black bass; Carpenter (1927), 399 p. p. m. in distilled water killed minnows, Leuciscus phoxinus, 
in 62 minutes; Catt (1934), 0.5 p. p. m. in lake water not lethal to white perch and yellow perch in 
15 hours, but 1 p. p. m. in lake water killed white and yellow perch in 1 to 10 hours; M. M. E., 2 
p. p. m. in hard water killed goldfish, Carassius auratus, in 24—96 hours; catfish, Ameiurus nebulosus, 
in 96-200 hours; 1 p. p. m., some goldfish in 72 hours; 1.25 p. p. m., the amphipods, Gammarus 
fasciatus and Eucrangonyx gracilis, in 17-20 hours; 10 p. p. m., the isopod, Mancasellus macrourus, 
in 16-48 hours; 1 p. p. m. in distilled water killed cladocerans, Daphnia magna, in 15 minutes to 2 
hours, and 0.25 p. p. m. in distilled water in 30 minutes to 3 hours. 
Ethyl alcohol, C2H5OH 
Fermented organic wastes, particularly fruit pulps, brewery and distillery wastes. Weigelt, 
Saare, and Schwab (1885), a 2-hour exposure to 10,000 p. p. m. in tap water survived by tench, 
Tinea vulgaris, without injury; Powers (1917), 250 p. p. m. in distilled water killed goldfish in 6-11 
hours. 
Ethyl amine, C 2 H 6 NH2 
Gas wastes. Shelford (1917). 400-800 p. p. m. in tap water killed orange-spotted sunfish, 
Lepomis humilis, in 1 hour. 
Ferric chloride, FeCB 
Dye industries; some ore milling operations; various chemical wastes. Powers (1917), 9 
p. p. m. in distilled water killed goldfish in 20 hours; Carpenter (1927), 270 p. p. m. in distilled water 
killed minnows, Leuciscus phoxinus, in 90 minutes; M. M. E., 100 p. p. m. in very soft water killed 
goldfish, Carassius auratus, in 1 hour to 1 hour 30 minutes, but same quantity of ferric chloride in 
hard water was not detrimental to goldfish in a 96-hour exposure. 
Ferric potassium sulphate, FeK(SO.s) 2 . Ferric alum 
Dye mordant; calico printing. Weigelt, Saare, and Schwab (1885), 1 minute exposure to 
10,000 p. p. m. not fatal to tench. 
Ferric sulphate, Fe 2 (S0 4 )3 
Chemical industries; as a coagulant for sewage precipitation. Clark and Adams (1913), 
0.716 p. p. m. in distilled water killed shiners, carp, and suckers in 12-24 hours. 
