EUDESMIN AND ITS DERIVATIVES. 461 
(needles), and then again from ethyl acetate until no change 
in the melting point could be observed. The colourless, 
rectangular plates melted at 163°. 
0°1302 gave 0°0840 AgCl. Cl = 15°8 
Co2HesOeCle requires Cl = 15°5 per cent. 
This compound is stable to bromine in carbon disulphide 
solution, and dissolves in sulphuric acid to a red solution 
which very quickly becomes dirty brown red and then 
slowly dark green and green blue, finally the solution 
becomes almost colourless and a black precipitate is 
produced. 
DIBROMEUDESMIN, (CONSTITUTION SIMILAR TO THAT SHOWN 
ABOVE FOR DICHLOREUDESMIN). 
A solution of bromine (12 gr.) in acetic acid (55 ccm.) was 
added in the course of five minutes to eudesmin (5 gr.) in 
acetic acid (25 ccm.) any rise of temperature being checked 
by cooling in running water. After a further five minutes 
a dilute solution of sodium sulphite was added and the 
crystalline precipitate collected and recrystallised from 
ethyl acetate. Although this solvent was found to be the 
most satisfactory for the crystallisation of large amounts of 
this bromo derivative, yet, when it is used a slight pink 
tint of the crystals cannot be removed, and, for analysis, 
a portion was crystallised from glacial acetic acid and so . 
obtained in the form of colourless prismatic needles which 
melt at 172°. 
0°1778 gave 0°1233 AgBr. Br = 29°5 
Co2HoxOsBre requires Br = 29°4 per cent. 
This compound always crystallises in needles and is very 
sparingly soluble in most organic solvents, readily, however, 
in chloroform. Its specific rotation was accordingly 
determined in this solvent. 
0°9182 made up to 25 ccm. with chloroform gave 
lal» Gije = + 69°4° 
