58 
TALCUM. 
Tale. 
A native hydrous magnesium silicate, official under the same name 
in the German Pharmacopoeia. The German Pharmacopoeia contains 
a dusting powder Pulvis salicylicus cum Talco consisting of salicylic 
acid, starch, and talc; some of the commercial talcum powders contain 
talc and boracic acid. 
Properties. — -Talc occurs as a grayish-green solid with waxy luster, 
or a white or pale gray powder. It feels greasy to the touch, hence 
it is popularly called soapstone. It is used as a dusting powder, and 
in some pill masses. 
TALCUM PURIFICATUM. 
Purified Tale. 
Talcum purified by treatment with hydrochloric acid. Used in the 
pharmacopceial method of preparing certain official waters of volatile 
oils. 
The same preparation is to be found in the National Formulary. 
THYMOLIS IODIDUM. 
Thymol Iodide. 
( Aristol .) 
(C 6 H 2 .CH 3 .C 3 H 7 .OI) 2 
Official in the French Pharmacopoeia as Diiodothymol. Variously 
known as aristol , annidalin , and thymotol. 
Chemistry. — Chemically it is dithymol-diiodide. It is obtained by 
the condensation of two molecules of thymol (a methylisopropylphe- 
nol) and the introduction into its phenolic group of two atoms of 
iodine: 
ch 3 
ch 3 
ch 3 
c 
c 
c 
/S 
/\ 
HC CH 
HC C- 
1! 1 
C CH 
HC COH 
II 1 
HC COl 
IOC CH 
\/ 
\/ 
w 
C 
c 
C 
c 3 h 7 < li c 3 h ; 
Thymol Dithymol-diiodide (Thymolis 
Iodidum) 
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 fatt} r oils and in ether, vaseline, chloro- 
form, and collodion. 
