516 FIXED OILS, FATS AND WAXES 



Description. Lard is a uniform, soft, white, homogeneous, fatty 

 substance melting at about 38 and having at 15 a specific gravity 

 of about 0-934: to 0-938. Odour slight, fatty, but not rancid or 

 otherwise disagreeable ; entirely soluble in ether. Acid value not 

 over 1-2; saponification value 192 to 198; iodine value 62 to 63; 

 unsaponifiable matter not over 0-5 per cent. ; refractive index at 60 

 14530 to 14550. 



Constituents. Lard consists of about 40 per cent, of stearin and 

 palmitin mixed with about 60 per cent, of olein, but these proportions 

 are subject to a little variation, and with them both melting-point 

 and specific gravity. 



Adulterants. Lard is liable to contain common salt, which is 

 often added to preserve it for domestic use ; it may be tested for 

 chlorides by boiling with water, cooling, filtering the aqueous liquid, 

 and adding silver nitrate and nitric acid. Starch, which might be 

 added to give it a whiter appearance, could also be detected in the 

 filtrate by solution of iodine. Sesame oil may be detected by the 

 test detailed under ' Olive Oil ' ( p. 510). 



But the most frequent adulterant of lard is cotton-seed oil, which 

 has been found in American lard, large quantities of which are 

 imported. It may be detected by the tests described under ' Olive 

 Oil ' and by a rise in the iodine number which should not exceed 60. 

 It should be noted that lard obtained from hogs fed upon cotton cake 

 may give a positive result with Halphen's test. 



BEESWAX 



(Cera flava ; Cera alba) 



Source, &C. Beeswax is the wax separated from the honeycomb 

 of the hive bee, Apis mellifica, Linne, and possibly other species of 

 Apis (Phylum Arthropoda, Class Insecta, Order Hymenoptera). 



Wax is a material secreted by the bee on the under surface of its 

 body, and employed to form the walls of the cells of the honeycomb. 

 After the separation of the honey the residual wax is purified by 

 melting with water, separating, and straining ; it then forms the 

 yellow wax of commerce. White wax is obtained by exposing thin 

 bands of yellow wax for several weeks to the action of air and sunlight, 

 occasionally watering it, and if necessary remelting, to promote the 

 bleaching by exposing fresh surfaces to these influences. Yellow 

 wax is also largely bleached by chemical means, such as the action of 

 chromic acid. 



Wax is imported from Jamaica, California, Chili, Egypt, Syria, 

 Madagascar, Morocco, &c. 



