22 



THE AMEKICAN MONTHLY 



[February, 



Only fresh butter should be exam- 

 ined for comparison, for butter that 

 is old develops different crystals of 

 salt, and becomes strongly active upon 

 the polarized ray, owing to the forma- 

 tion of acids. In old butter, we find the 

 field full of branching crystals of salt 

 (fig. 5), and the cubes of salt instead 



Fig. 5. — Salt-crystals from old butter. 



of being clean cut with smooth edges, 

 are rough and jagged. With the po- 

 lariscope and selenite, when the field 

 is red, innumerable spots and blotches 

 of bright blue, many of them of con- 

 siderable size, will be seen, and ex- 

 tremely minute acicular, colorless 

 crystals, with an increased amount of 

 the granular matter present. 



If any adulteration has been ef- 

 fected, it will be detected by its ap- 

 pearance, in addition to the above de- 

 scribed characteristics. An excess 

 of brine, or salt, is sometimes pur- 

 posely added, but unless the excess 

 of brine be considerable it is probably 

 not a wilful adulteration, but the re- 

 sult of imperfect w^orking. 



The chief adulteration of butter 

 now practised is undoubtedly the ad- 

 mixture of lard, producing the article 

 called "suene," and sometimes "but- 

 terine." This product, when freshly 

 made, is indistinguishable by taste or 

 smell from the best pure butter, and 

 in cold weather it keeps in this con- 

 dition for a considerable time. Deal- 

 ers and manufacturers claim to be 

 able to distinguish this from pure 

 butter by " the grain," as they call it. 

 The tryer, when withdrawn from a 

 tub of butter, has a " velvety feel " 

 and a peculiar soft look, while from 

 suene it has a " grainy feel " and look, 

 and from oleomargarine a "waxy 

 feel " and " greasy " appearance, they 



say. This difference is not readily 

 perceptible to a tyro, but is highly 

 probable in view of the structure re- 

 vealed by the microscope in the sev- 

 eral articles. 



Under the microscope with a i-inch 

 objective, suene is seen to have a 

 spotted appearance, quite different 

 from that of pure butter; and the 

 darker spots are balls of very fine 

 needle-like crystals radiating from a 

 central core, resembling miniature 

 chestnut burs; these occur singly and 

 in clusters, mixed with the oil-glob- 

 ules of the butter and with the cubi- 

 cal crystals of salt, and some separate 

 needle-like crystals (fig. 6). 





•0 



Fig. 6. — Suene. 



These balls of crystals are marga- 

 rine or stearine, and represent the 

 quantity of lard present in the sample; 

 for pure lard is wholly composed of 

 these crystals with a little water. The 

 amount of aggregated and free crys- 

 tals present, as found by a ^-inch 

 objective, therefore gives a nearly ac- 

 curate measure of the amount of lard 

 in a given sample of suene. 



This adulteration is not, probably, 

 injurious to health, but few people 

 will relish the idea of buying lard at 

 the price of butter; yet in all the large 

 cities immense quantities of this su- 

 ene are manufactured under various 

 names. In Chicago about twenty fac- 

 tories are said to be in full operation. 



Lard-crystals polarize beautifully, 

 and the lard mixed with butter is 

 readily seen when the polariscope is 

 used, the balls of crystals showing a 

 dark centre with very bright edges, 

 and the separate needles showing 

 brightly. 



Oleomargarine, like suene, when 

 fresh, closely resembles butter in taste 



