460 Proceedings Columbia Biochemical Association XApril-july 



A study of the diffusibility of these substances through rubber 

 and collodion membranes indicates that they are not true lipo- 

 chromes. They diffuse readily from alcohol to alcohol, but do not 

 diffuse from alcohol to ether or ether to alcohol. An alcohol- 

 water System causes a precipitation of the chromes in the bag. This 

 precipitate may be redissolved in alcohol. 



The reactions of these pigments with various reagents are sug- 

 gestive. They are all decolorized by strong acids, and oxidizing 

 and reducing agents. Their behavior to alkalis is highly specific. 

 The yellow chrome is not altered at all by alkalis. The two orange 

 colors react in totally different ways. The orange of the aurococcus 

 is turned to yellow and regains its orange tinge on neutralization ; 

 that of the S. aurantiaca is turned to a pink. The red chrome is un- 

 affected, and the white is not a distinct pigment. Dilute acid 

 changes the aurantiaca chrome to yellow and leaves the other un- 

 affected. Conc. sulphuric acid turns the evaporated residues of all 

 the pigments to dirty bluish or greenish, This is a characteristic 

 lipochrome reaction. 



A hint as to the relationship of these organisms may be obtained 

 from the reactions of their pigments. Yellow is the stable color re- 

 curring in all the forms and is apparently basic for the group. The 

 chrome of 5. aurantiaca is related both to the yellow and 

 red, and may form a connecting link between them, while the 

 orange of the aurococcus is related to the yellow on the one band and 

 grades into the white on the other. It might be surmised, from the 

 pigment relations of the group, that the yellow micrococci are most 

 primitive, leading up on the one band by way of the aurococci to 

 the albococci and Streptococci, and on the other by the yellow sar- 

 cinae and S. aurantiaca to the red-pigment forms. 



124. The effect of selenium Compounds upon catalase and 

 other enzymes. Victor E. Levine. The Compounds of selenium 

 employed were selenium dioxid (selenious acid), selenic acid, so- 

 dium selenite, sodium selenate and potassium selenocyanate. The 

 effect upon catalase was determined as f ollows : Healthy normal 

 dogs were bled to death from a femoral artery, under local cocaine 

 anaesthesia. Weighed amounts of defibrinated blood and tissues 

 were ground with sand in a mortar, treated with 40 c.c. of dist. 



