98 The Philippine Journal of Science 1917 



and of diazobenzene sulphonic acid with a few organic acids, 

 alcohols, and aldehydes. 



Table I. — Color reactions of organic acids, aldehydes, and alcohols. 



Name of compound. 



Result with fuchsin-sulphur- 

 ous acid. 



Result with diazobenzene 

 sulphonic acid. 



Formic acid 



None 



Slightly violet. 



Reddish violet. 



Yellow. 



Cherry red. 



Yellow. 



Slightly violet after short 



time. 

 Reddish violet. 

 Deep violet directly. 

 None. 



Do. 

 Deep violet after short time. 

 Violet. 

 Violet (good). 



Do. 



Do. 

 None. 



Do. 



Do. 



Do. 

 Faintly violet. 



Do. 



Do. 

 Violet. 

 Faintly violet. 



Do. 

 None. 

 Red. 

 Yellow red. 



Acetic acid 





P • 'd 



















None 



Violet _ 







Oxalic acid - 



do 



do 



Free fatty acids from coconut oil » 



















Glycerol (old; slightly colored) 



Glycerol (old; air passed through 



do 















































* This coconut oil gave no test with the reagents before saponification. 



The compounds used for the color tests were Kahlbaum pro- 

 ducts. A study of the results indicates that the tests are 

 not due to the presence of aldehydes, since identical reactions 

 occurred with other compounds. 14 Color reactions were given 

 by acetic, propionic, butyric, valeric, stearic, and glycollic acids; 

 by ethyl, butyl (normal), isobutyl, butyl (tertiary), amyl, heptyl, 

 and ethylene alcohols; and by acetyacetone with the fuchsin- 

 sulphurous acid reagent. Positive or confusing tests were given 

 by acetic, butyric, stearic, oleic, glycollic, and malonic acids ; 

 by ethyl, butyl (normal), isobutyl (tertiary), amyl (normal), 



14 A more thorough investigation of the property of organic compounds 

 to give color with these reagents is now under way in this laboratory. 



