2 94 American Quarterly Microscopical Journal. 



OLEOMARGARINE AND BUTTER. 



BY THOMAS TAYLOR. 



{Received July 2d, i8jg.) 



In making inYCstigations \vith the Yiew of distinguishing 

 oleomargarine from butter, I submit the specimens to the follow- 

 ing tests : I. Specimens of each are placed on glass slides, and 

 subjected to a uniform heat on a marble slab. The oleomargarine 

 will melt first. Oleomargarine as manufactured and sold contains 

 a large amount of fatty, star-like crystals and Yery small dark- 

 brown, nitrogenous bodies, Yarying in size from one to U\o 

 thousandths of an inch. The star-shaped crystals Yary in diameter 

 from t\vo to Ayc thousandths of an inch. If oleomargarine is 

 boiled and rapidly cooled by the use of ice-water, a solid portion 

 will form at the bottom of the Yessel containing it, while an oily 

 portion will remain aboYe. The latter, when Yiewed under 

 the microscope, with powers of from one to three hundred 

 diameters, will appear like pure, unboiled butter. No fatty 

 crystals will be seen. The only indications of oleomargarine will 

 be the presence of the few dark-brown, nitrogenous bodies which 

 are always present in more or less abundance in oleomargarine. 

 The solid portions of the boiled oleomargarine tested in the same 

 way will rcYeal a mass of stellate and feathery crystals, coYering 

 the entire field. These crystals Yary in diameter from two to fiYC 

 thousandths of an inch. 



Sometimes small portions of animal tissue and CYen blood- 

 vessels are seen in oleomargarine, indicating that the latter has not 

 been carefully prepared. If a portion of pure butter is boiled and 

 allowed to cool in the manner described above, a solid portion 

 will appear at the bottom with the oily portion floating upon it. 

 Separate the two parts and examine them as before. The oily 

 portion will appear as a mass of stellate crystal forms or starry 

 crystallized fat. Very few oil globules will be observed. According 

 to my observations, the oily portion of boiled butter differs very 

 materially, in appearance, from that of boiled oleomargarine. 



The solid portion of boiled butter contains all the salt used 

 in its manufacture. When viewed through the microscope it 

 appears very cloudy, and full of stellate crystals. Boiled but- 

 ter retains its buttery odor. Oleomargarine when boiled has 

 a fatty odor. Heating or boiling tends to increase the size of 



