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TALCUM. 
Talc. 
A native li3^drous magnesium silicate, official under the same name 
in the German Pharmacopoeia. The German Pharmacopoeia contains 
a dusting powder Pulvis salic^dicus cum Talco consisting of salic^dic 
acid, starch, and talc; some of the commercial talcum powders contain i 
talc and boracic acid. 
Properties. — Talc occurs as a grayish-green solid with waxy luster, j 
or a white or pale gray powder. It feels greas}" to the touch, hence il 
it is popularh^ called soapstone. It is used as a dusting powder, and 
in some pill masses. 
TALCUM PURIFICATUM. 
Puri fled Talc. 
Talcum purified treatment with hydrochloric acid. Used in the i 
pharmacopoeial method of preparing certain official waters of volatile 
oils. 
The same preparation is to be found in the National Formulaiw. 
THYMOLIS lODIDUM. 
Thymol Iodide. 
{Ariatol.) 
(Ceib.cH3.O3Tb.oi)., * : 
Official in the French Pharmacopoeia as Diiodothymol. Variouslv 
known as aristol, annidctUn^ and thyrnotoL ' 
Chemistry. — Chemically it is dithymol-diiodide. It is obtained by 
the condensation of two molecules of thymol (a methylisopropydphe- 
nol) and the introduction into its phenolic group of two atoms of 
iodine: 
CH3 
CII3 
i 
CH3 
1 
1 
c 
1 
c 
1 
c 
/\ 
HC CH 
II 1 
HC C 
. 
G GH 
IL 1 
HC COH 
II 1 
HC COI 
IOC CH 
\/ 
\/ 
\/ 
G 
c 
c 
I I i 
C3H, C3H, C3II, 
Thymol Dithymol-diiodidc (Thymolis 
lodidum) 
Character. — A bright, chocolate-colored or reddish-yellow, bulky 
powder, almost tasteless, and having a slight aromatic odor. 
Solubility. — Insoluble in water and glycerin, soluble with difficulty 
in alcohol, readily soluble in fatty oils and in ether, vaseline, chloro- 
form, and collodion. 
