STREAM POLLUTION 
425 
action of heavy metals on fishes and other aquatic organisms. Two general statements concerning 
the lethality of lead may be given here. Other references follow under the several salts of lead. 
Carpenter (1927) believes that as little as 0.33 p. p. m. of lead may be lethal to fresh-water fishes, 
and Billing, Healey, and Smith (1926) found that 4 p. p. m. of colloidal lead retarded the growth of 
young plaice. 
Lead acetate, Pb(C 2 H 3 0 2 )2. Sugar of lead 
Rushton (1922), 10 p. p. m. in stream water killed yearling trout; Carpenter (1925), 5 p. p. m. 
in distilled water killed minnows, Leuciscus phoxinus, in 4—16 hours, and 10 p. p. m. in distilled 
water, if renewed every other day, killed goldfish in 12 days. 
Lead nitrate, Pb(N0 3 ) 2 
Rushton (1922), 10 p. p. m. in stream water killed trout in 2 hours 15 minutes; Carpenter (1925), 
250 p. p. m. in distilled water killed goldfish in 4-5 days and minnows, Leucisus phoxinus, in 2-3 
hours; Dilling and Healey (1926), 1.6 p. p. m. retards growth of tadpoles and 3.3 p. p. m. lethal 
for tadpoles in tap water; Carpenter (1930), 165 p. p. m. in distilled water, if given sufficient exposure 
will kill steel-colored minnow, Notropis whipplii; common shiner, Notropis cornutus; blunt-nosed 
minnow, Hyborhynchus notatus; silver-mouthed minnow, Ericymba buccata; sucker-mouthed minnow, 
Phenacobius mirabilis; creek chub, Semotilus atromaculatus ; stoneroller, Campostoma anomalum; 
common sucker, Catostomus commersonii; chub sucker, Eriomyzon sucetta; Johnny darter, Boleosoma 
nigrum; fan-tailed darter, Etheostoma jlabellare; log perch, Percina caprodes; and bluegill, Lepomis 
pallidus; M. M. E., 100 p. p. m. in hard water fatal to goldfish, Carassius auratus, in 80 hours; 10 
p. p. m. in hard water, without apparent injury to goldfish, in 96 hours’ exposure. 
Lead sulphate, PbSCh 
Carpenter (1925), 25 p. p. m. in distilled water killed goldfish, Carassius auratus, in 4 days, 
and minnows, Leuciscus phoxinus, in 2—3 hours. 
Lithium chloride, LiCl 
Found in some mineral springs. Powers (1917), 3,750 p. p. m. in distilled water killed goldfish 
in 22-27 hours. 
Magnesium chloride, MgCl 2 
A component of various waste waters from oil wells, and some industrial wastes. Garrey (1916), 
476 p. p. m. in distilled water killed straw-colored minnow, Notropis blennius, in 4-6 days; Powers 
(1917), 6,757 p. p. m. in distilled water killed goldfish in from 78 hours to 21 days; Wiebe, Burr, and 
Faubion (1934), 5,000 p. p. m. in distilled water killed golden shiner, Notemigonus crysoleucas, 
in 96 hours. 
Magnesium nitrate, Mg(N0 3 ) 2 
Powers (1917), 12,500 p. p. m. killed goldfish in 14-16 hours. 
Mercuric chloride, HgCl 2 . Corrosive sublimate 
Weigelt, Saare, and Schwab (1885), 500 p. p. m. in tap water killed large trout in 54 minutes; 
Carpenter (1927), 13.6 p. p. m. in distilled water killed minnow, Leuciscus phoxinus, in 42 minutes. 
Methyl alcohol, CH 3 OH 
A solvent in many industrial operations. Weigelt, Saare, and Schwab (1885), a 2-hour exposure 
to 10,000 p. p. m. in tap water was tolerated by trout without apparent injury; Powers (1917), 
250 p. p. m. in distilled water killed goldfish in 1 1-15 hours. 
Methyl mercaptan, CH 3 SH 
A highly toxic constituent of sulphite paper pulp waste. Cole (1935a), 1 p. p. m. in lake water 
killed white bass, Roccus chrysops, in 1 hour, 45 minutes, or less; yellow perch ( Perea jlavescens), 
largemouth black bass ( Micropterus salmoides), smallmouth black bass ( Micropterus dolomieu), 
and bluegill ( Lepomis pallidus), in 6-8 hours; and rock bass ( Ambloplites rupestris) , in 11 hours. 
