50 ANALYSIS AND ADULTERATIONS OF BUTTER. 



Practically therefore it is impossible, by even scientifically 

 conducted methods of adulteration, to evade detection by 



"We think it proper, however, here to mention the fact, that 

 there is one fat which might perhaps be used to adulterate 

 butter, which contains, according to our analysis, an equally 

 low percentage of insoluble fatty acids, namely, cocoanut oil. 

 All other fats examined, animal or vegetable, as the fat of 

 mutton, beef, or pork, palm oil, cocoa butter, olive and 

 other oils, yield the normal percentage of 95*5 per cent., 

 or figures closely approaching it. 



DESCRIPTION OF THE METHOD. 



The small beaker containing the pure butter-fat obtained 

 by filtration as described, is weighed, and a quantity approach- 

 ing three or four grammes is taken out by means of a dry glass 

 rod, and transferred into an evaporating dish. The rod is 

 put into the dish, the beaker again weighed, and the quantity 

 of butter-fat taken thus ascertained by difference. The dish 

 should be a deep one, about five or six inches in diameter, and 

 well glazed, one with glazed edges being preferable. The fat 

 is then fused on the water bath, and about 50 c,c. of alcohol 

 of about 85 per cent, are added. Methylated spirit may be 

 used, provided it be free from resinous matter, which it so 

 frequently contains. As soon as the alcohol gets warm, 

 the butter-fat easily dissolves, especially when gently 

 stirred with the glass rod, forming a clear yellow solu- 

 tion. Whether the whole of the fat be dissolved or not, 

 a small bit of pure caustic potash or soda, weighing about 

 one or two grammes, is now added and agitated in the liquid, 

 in which it but slowly dissolves, care being taken not to allow 

 the alcohol to be heated to its boiling point, as loss by spurting 

 would be inevitable. Sauonification proceeds rapidly, and is, 



