6 TECHNICAL BULLETIN 2 3 8, U. S. DEPT. OF AGRICULTURE 
pigs in 6 days ; 20 milligrams killed a rabbit in 4 days and another 
in 0 days, and 40 milligrams in 4 days. Unfortunately, however, 
the body weights of the animals are not reported, so that calcula- 
tions of results in the customary terms of milligrams per kilogram 
can not be made. A dog received 100 milligrams subcutaneously 
(11 milligrams per kilogram), which caused posterior paralysis and 
loss of appetite for 10 days, although the animal survived. 
Table 1. — Toxicity of thallous salts administered orally to dogs, as determined 
hy Sivai7i and Bateman {IJ^l) 
Salt used 
Days until death, after doses (in milligrams per 
kilo of body weight) were given of— 
13 
17 
19 
20 
26 
45 
Thallous acetate (TlCjHiOj) 
8 
9, 15 
Thallous nitrate (TIN Us).. 
15 
4 
Thallous sulphate (TljSOi) 
12 
Oral administration to dogs gave the results listed in Table 1. 
The minimum lethal dose can not be determined from these data, 
since all test animals died, but it appears to be less than 13 milli- 
grams per kilo. 
The authors conclude that thallium is more toxic than lead, being 
about as potent as arsenic. The administration of 200 milligrams 
to a dog over a period of 13 days produced the same effect as when 
administered in 4 days, from which the authors conclude that there 
is no tolerance for thallium, but a cumulation of action. 
The first symptom noted by Swain and Bateman after admin- 
istration of thallium was lack of coordination in locomotion, local- 
ized in the hind legs of the quadrupeds. Trembling, great dilatation 
of the pupils, emesis, congestion of the gastrointestinal tract, in- 
creasing albuminuria, increased urinary volume, and alopecia were 
noted in most animals; dogs also show^ed a marked increase in the 
flow of tears and of bile. A blue line appeared upon the gum mar- 
gins. Finally respiratory distress developed to cause death by 
asphyxia. There was no indication of heart failure, toads' hearts 
continuing to beat for some time after the respiration ceased. Some 
lesions of the kidneys were noted after 200 milligrams (17 milligrams 
per kilo) were given, but they were not considered sufficiently severe 
to cause death, and the suggestion is offered that thallium may favor 
the production of uremic poisoning. Nephritis was established. 
Herfs (5, 86) in 1924 lauded thallium highly; he claimed that 70 
milligrams of thallium per kilo killed rats in 2 days and that smaller 
doses killed in 8 to 14 days, by action upon the central nervous 
system. House mice w^ere killed by 2 or 3 grains of thallium-treated 
wheat; 10 mice consumed 262 of 400 kernels of normal wheat and 
304 of 400 treated kernels. Cataract was not observed. 
In perfusing isolated frog hearts by the Straub method, 0.03 to 
0.05 milligram of thallium sulphate caused stoppage of the heart in 
diastole in 10 to 15 minutes {23). The action was antagonized by 
the addition of calcium to the perfusion solution. Retardation of 
growth of rats and other warm-olooded animals by thallium is due 
