4 TECHNICAL BULLETIN 2 3 8, U. S. DEPT. OF AGRICULTURE 
The quantitative method of determination as furnished by the 
German company is as follows: 
About 1 g:ram of paste or 2 grains of grain is weighed and intimately mixed 
with 15 to 20 grams of sodium carbonate (anhydrous) in a 70 c. c. porcelain 
crucible. 
Heat for ly^ hours just under fusion temperature. Cool and transfer contents 
of crucible to a boaker or Erlomeyer flask containing 50 c. c. of water. Wash 
the crucible thoroughly with dilute hydrochloric acid and add the washings 
to the flask. When all the sodium carbonate has been decomposed with hydro- 
chloric acid, a large excess is added (about 20 to 25 c. c.) and the liquid heated 
to boiling. Potassium chlorate is added slowly until probably 2 grams has 
been added and the liquid smells strongly of chlorine. 
Evaporate till salt separates, add more w'ater (150 c. c), and evaporate 
again. Be sure that no free chlorine is in the liquid. Cool and add 10 to 
15 c. c. of N/10 sodium thiosulphate and 1 gram of potassium iodide. Let 
stand 5 minutes and titrate the thiosulphate with N/10 iodine solution. 
Calculation : 
40,000: 508 = No. c,c, NajSjOs.S HjOia;^ rp, 
— . , . f i — . X 1 00 = per cent 1 IjbOi 
Weight of sample m grams 
This method gives good results and requires no particular skill to operate, 
ACTION OF THALLIUM ON BACTERIA 
Buschke and Jacobson {^3) reported in 1922 that thallium has a 
strong oligodynamic action on Bacillus coli, typhoid and dysentery 
bacteria, streptococci, and staphylococci, but not on molds. When 
a piece of metallic thallium is placed in the center of an agar plate 
containing viable organisms, a clear zone of dead bacteria is pro- 
duced over an area 7 to 14 millimeters in diameter. This action 
disappears when air is removed, but returns upon reexposure, a 
result suggesting that air oxidizes Tl to TLO, which dissolves to 
form TIOH (^i). Concentrations of thallium acetate or carbonate 
as strong as 1:1,000 (1,0(X) milligrams per liter) are required to 
inhibit the growth of Bacillus coli. 
The cost and the scarcity of metallic thallium prevent commercial 
application of this property. 
ACTION OF THALLIUM SALTS ON ANIMALS 
GENERAL ACTION 
Lamy (P^), who was working upon thallium in France at the time 
Crookes discovered it in England, offered milk containing 5 grams of 
thallium sulphate to two young puppies; they drank only a small 
quantity, then refused to drink the remainder. In spite of every 
effort to save them, both died in four days. Six ducks, two hens, and 
a dog consumed a portion of the milk solution. During the day 
the dog became restless, salivated, and refused food; during the 
night, constipation and respiratory distress developed. The hind 
limbs of the dog and the legs of the ducks and hens became paralyzed. 
All animals died or were moribund 64 hours after taking the milk 
thus treated. Ten milligrams of thallium sulphate killed another 
dog in 40 hours, with manifestation of the same symptoms. 
Grandeau {80) found in 1863 that 1 gram of thallium sulphate 
killed a dog in five days with all the symptoms of lead poisoning, 
whereas in another dog 1.5 grams of lead acetate caused emesis, but 
