149 
solution containing 0000012 per cem does already not show the 
two faint bands but a dark band which is dissolved into three 
when using a still more diluted solution (0‘0000062 g per eem), 
of which the darkest is situated in front of the F line, the second, 
fainter one past that line, and the third, faintest, in the neighbour- 
hood of the k line. 
The study of the bixin spectrum will no doubt fascilitate the 
examination of foodstuffs adulterated (dyed) by it. 
The alkaline salts of bixin. 
The alkaline salts were already twice the subjeet of investiga- 
tions. Eitti found that bixin may form two series of salts, the 
first eontain one atom of metal. the others two. This author obtai- 
ned the metalie compounds by the action of sodium carbonate 
or potassium carbonate on the alcoholie solution of bixin. Zwick, 
who repeated the experiments of the former observer eould not 
get by this method any crystals, he obtained them however by a 
different method, namely by acting upon a bixin solution (prepared 
by using a 120/, alcohol) with a solution of potassium hydroxide. 
The composition of the potassium salt corresponds to the formula 
Css Hz, K, O, + 2H,0. Zwick states that his method does not always 
lead to a crystalline product but he is unable to describe the con- 
ditions which are necessary for obtaining them. 
We have found that the preparation of the monobasie salts does 
not present any difficulties if the following conditions are ob- 
served: 0:23 & of metalic sodium are dissolved in 75 em of 700) 
alcohol and the solution mixed with a suspension of 45 & of bixin 
in 75 cem alcohol of the same strength. The whole ıs heated on 
the water bath until a clear solution results, and quickly filtered. 
In the filtrate very soon the formation of glittering erystals takes 
place. These were filtered off, washed with a little alcohol, reery- 
stallized from 70°/, alcohol and dryed at 300 Drying at a higher 
temperature is not advisable, the substance absorbs oxygen and 
alters its dark copper red colour, turning orange. 
Analysis: 
03040 g subst. gave 0:‘0481 & Na, SO, 
found theory Cs; H;3 O, Na 
Na: 5:120), 4.87%), 
The potassium salt may be obtained under the same conditions 
