628 POISONS : THEIR EFFECTS AND DETECTION. [§ 794 . 
165°, and the temperature kept up by adding fuming hydrochloric acid 
through the funnel at the rate of from 50 to 60 drops a minute. After 
1J hour all the antimony is in the receiver. The tin can now be dis¬ 
tilled ; for this purpose the tap funnel is filled with a solution of bromine 
in fuming HC1, and 6 c.c. of concentrated sulphuric acid added. Sulphur 
dioxide is now passed through, and the temperature kept constant 
180°-190°. In an hour all tin has distilled over, and the sulphur dioxide 
is displaced by a current of carbon dioxide. 
Antimony compounds dissolved in HC1 (1 : 4) or dilute H 2 S0 4 (1 : 10) 
and treated with a solution of potassium iodide and caesium chloride 
(1 of KI to 3 of CsCl in 10 c.c. water), give the insoluble antimony 
caesium iodide in yellow or garnet-red hexagonal lamellae. This will 
detect a thousandth of a milligramme of antimony in presence of 500 
times its weight of arsenic. 1 Marsh’s test (already described) may, if 
antimony be present, reveal its presence by the character of the stain ; 
practical chemists would not, however, in a special search for antimony 
use Marsh’s test, but proceed in the manner already detailed. 
Antimony in the Urine. —W. Bean and G. A. Freak ( Analyst , 
1919) have improved on a colorimetric method of Schidrowitz and Golds- 
borough ( Analyst , 1911) in the estimation of small quantities in the 
urine of patients treated with intravenous injections of tartar emetic. 
A strip of copper foil about 1-5x10 cm. is made into a coil, and, as in 
the method of Beinsch, boiled in the urine strongly acidified with 
hydrochloric acid—say, to 100 c.c. of urine, 20 c.c. of concentrated 
hydrochloric acid. When deposition is complete, the coil is removed, 
immersed in a beaker of water, and then rapidly transferred to a boiling 
alkaline permanganate solution, consisting of 15 c.c. of 1 per cent. 
KOH, and an amount of potassium permanganate solution (1 c.c. =0-01 
grm. iron) depending on the quantity of antimony on the copper foil. 
The amount of antimony may, with a little experience, be judged 
sufficiently accurately by the appearance and depth of the stain. For 
less than 0-3 mgrm. antimony 0-5 c.c. permanganate is enough, and the 
boiling should not be more than a minute ; for 0*5 mgrm. antimony 1 c.c. 
of permanganate, and for 0-1 mgrm. antimony 2 c.c. of permanganate : 
in these thicker deposits the boiling may extend to five minutes to 
complete decolorisation. I 11 every case there must be no black stain 
remaining on the copper on treatment with hydrochloric acid (1 : 5). 
Should a black stain remain, the foil after washing is again treated 
with permanganate. The antimony in solution is filtered and the 
alkali neutralised with hydrochloric acid and then further acidified, so 
as to provide an excess of 0-2 strong acid. Sulphur dioxide is then passed 
through the solution until saturated ; it is then boiled off, concentrating 
down to 10 c.c. After cooling, 0-5 c.c. of 10 per cent, gum solution is 
1 Georges Deniges, Cornet. Rend., 1901. 
