xii. a, 2 Brill and Parker: Philippine Coconut Oil 99 



and ethylene alcohols; and by acetylacetone with diazobenzene 

 sulphonic acid. Tests were given by the free fatty acids of 

 coconut oil, by formaldehyde, acetaldehyde, and paraldehyde 

 with both reagents, but the four samples of glycerol responded 

 negatively. 



Color reactions were given by various alcohols, aldehydes, and 

 acids with diazo-benzene sulphonic acid and with fuchsin- 

 sulphurous acid. As these compounds are Kahlbaum chemically 

 pure products, it hardly seems plausible to assert that the com- 

 pounds reacting to give the color could be aldehydes present as 

 impurities. 



In Table II are recorded some data on coconut oils in the pos- 

 session of the Bureau of Science. 



An examination of the records of Table II reveals some in- 

 teresting relationships, namely, Nos. 38 and 44, with low acid- 

 ity, both show rancidity when tested by their organoleptic 

 properties ; on the other hand, Nos. 13, 22, 26, 34, 36, 39, 46, and 

 47 show relatively high acid values compared with that of fresh 

 oil (usually about 0.2 per cent calculated as oleic), but are free 

 from rancid odors. These results indicate that the acidity of 

 coconut oil is not a measurement of the rancidity. 



Samples 2, 5, 7, 8, 9, 10, 11, 32, 37, 38, and 45 have a rancid 

 odor, but do not restore the color to decolorized fuchsin, while 

 the color is restored by samples 26, 28, 33, 40, and 41, which 

 do not possess a rancid odor. The existence of no relationship 

 between the restoration of the color of fuchsin and the odor of 

 the oil is indicated by these results. The results with diazo- 

 benzene sulphonic acid are equally interesting. Oils with rancid 

 odors which do not give a color are Nos. 1, 3, 8, 9, 10, 38, and 45, 

 and those giving a color but not possessing a rancid odor are Nos. 

 26, 28, 36, 39, 40, 41, and 42. 



If the color with these two reagents arises from the same 

 cause, it is impossible to explain the formation of color products 

 with decolorized fuchsin in the case of samples 1, 3, and 33 and 

 the absence of color of these samples with diazobenzene sulphonic 

 acid, or the color given by Nos. 2, 5, 7, 11, 32, 36, 37, 39, and 42 

 with diazobenzene sulphonic acid and the absence of color with 

 decolorized fuchsin. Diazobenzene sulphonic acid is considered 

 a more sensitive reagent for the detection of aldehydes than is 

 fuchsin. This explains why color resulted with diazobenzene 

 sulphonic acid, but not with fuchsin, the latter results, but does 

 not explain the preceding results. Oils which agree in all re- 

 spects in the so-called rancidity tests are Nos. 17, 18, 19, 

 and 27, which possess no rancid odors, no high acidity, and do 



