112 



Journal of Agricultural Research 



Vol. VI, No. 3 



Table VIII. — Amount of stearic acid in the insoluble acids of palm oil 



o Average. 



* Molecular weight of the several precipitates, 284.38. 



The stearic acid obtained from the insoluble acids of butter fat by the 

 method described ranges from 7 to 22 per cent, which is considerably in 

 excess of the amount generally credited to the product. The prevaiHng 

 opinion was supported undoubtedly by the fact that only a small amount 

 of precipitate is obtainable by the Hehner and Mitchell (3) method, as 

 shown by several investigators. 



The amount of s'^earic acid appears to be affected by the feed the animal 

 receives. Samples 9, 10, and 11, averaging 16.67 P^^ cent, were from 

 cows fed beef tallow; samples 17, 18, and 19, averaging 14.48 per cent, 

 were from those fed palm oil; while samples 4 to 8, 14 to 16, 20 and 21, 

 averaging 8.70 per cent, were from those fed a ration low in fat. It is 

 probable that the individuality of the animal and period of lactation 

 also affect the composition. The entire matter of the effect of food as 

 well as other influences upon the chemical character of butter fat is now 

 being further studied. 



The stearic acid (8.91 per cent) recovered from the insoluble acids of 

 palm oil exceeded the amount usually reported. 



SUMMARY 



The results of the determinations of stearic acid in the insoluble acids 

 of butter fat by the method proposed show a higher percentage of stearic 

 acid than has been generally reported. The facts that the results are 

 concordant and that the molecular weight determinations of the crys- 

 tallized product secured by the proposed method agree closely with the 

 theoretical molecular weight leave no doubt as to the identity and 

 approximate purity of the stearic acid. 



