40 OLIVK OIL AND ITS ST HS'I ITTTES. 



acid. Allen" confirms the statement of Yalenta. but suggests that the 

 solubility of an oil is greatly increased by a high percentage of free 

 acids. The strength of acetic acid used, according to this author, may 

 vary considerably without greatly affecting the solubility. Hurst, '' on 

 the other hand, finds that rape and colza oils are completely dissolved 

 by glacial acetic acid and gives the temperature turbidity of from 7-"> 

 to '.'.) . Thomson and Ballantyne ( ' have also studied this question and 

 find that Valenta's statement holds good only when acetic acid of spe- 

 cific gravity 1.05fte is employed; if ah acid of specific gravity l.o.M^ 

 is u>ed rape oil is completely soluble. 



In working in this laboratory upon Valenta's test with acid of 4 .W.5 

 per cent strength it was found that rape oil and mustard oil both dis- 

 solve completely at a temperature of 120 C., although at a very 

 slightly reduced temperature the oils are again partly precipitated. 

 Olive oil is readily soluble at 120, but precipitates again upon a slight 

 reduction of temperature. Mixtures composed of 20 per cent and 40 

 per cent of rape oil with olive oil and similar mixtures of mustard 

 oil showed no distinction from pure olive oil in respect to solubility. 

 Hence as a means of detecting rape oil, and especially mixtures of the 

 same with olive oils, this test must be considered of little value. 



SUNFLOWER OIL. 



Sunflower oil has a mild taste and pleasant odor, and the cold drawn 

 oil is said to be used in some sections of Europe for culinary purposes. '' 

 The physical and chemical characteristics of this oil are so widely dif- 

 ferent from those of olive oil that additions of even relatively small 

 amounts to olive oil would be sufficient to make the values of the latter 

 abnormal. The compiled results of the analyses of sunflower oil are 

 given in Table XXIX. 



Jour. Soc. Clu'in. hid., is.sii, :: lit), 2S2. 

 ''Jour. Soc. Chein. Ind., 1887, (J: .. 

 c Jour. Soc. Chen. . Iml., 1H<)1, 10: '2:\:\. 

 ^Jour. Soc. Chein. Ind., 1892, 11: p. 470. 



