IOWA ACADEMY OF SCIENCES. 
177 
time, became spotted here and there with small violet 
spots. 
Rice Flour . — There was a better growth and greater pro- 
duction of color on the rice flour than on any of the other 
solid media used. The growth is spreading, dark purple, 
thick at first, and becoming very much wrinkled. 
Blood Serum . — Growth good. 
Egg Albumen . — Coagulated albumen of egg was also 
tested and proved to be excellent as a ‘culture medium. 
Growth very thick and heavy. 
Pigment . — The purple pigment is soluble in alcohol, but 
not in ether, chloroform or xylol. The results obtained by 
^Schneider were checked as follows: The addition of 
ammonia changes the color to a blue or blue-green, as is 
the case when sodium hydrate is added. The addition of 
normal hydrochloric acid decolorizes the solution. When 
the solution is evaporated to dryness and the purple resi- 
due is treated with sulphuric acid a yellow solution is 
formed. 
A strong alcoholic solution when allowed to stand for a 
period of three weeks, tightly corked, was found to have 
lost its purple color and to have become almost trans- 
parent, but with a reddish-brown tinge. This solution, 
when treated with acids and^alkalies, bahaved as did the 
original purple solution. 
♦Die Bedentung der Bakterienfarbstoife. Separatabdruck aus den Arbeiten des 
Bakterial. Instits der Qrossh. Hochschule zu Karlsruhe. 25. 
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