838 



FOODS AND FOOD ADULTERANTS. 



separated was well washed with boiling water, dissolved in absolute alcohol, and fil- 

 tered. On cooling, crystals of pure cerin separated. These had a fusing point of 

 67 C. (Brodie says 78 C.), and were soluble in six parts of boiling alcohol. Brodie's 

 analysis with chromate of lead gives for the formula, C M H 6 4O4=carbon, 78.98 per 

 cent; hydrogen, 13.12 per cent; oxygen, 7.90 per cent. Cerotic ether can be made 

 by dissolving the acid in absolute alcohol and passing hydrochloric acid gas through 

 the solution. It has the appearance of a soft wax, and fuses at 59 C. Cerolein, 

 that portion which is soluble in cold alcohol, is a soft, greasy body, soluble in ether, 

 chloroform, and benzine; fuses at 81.5 C., renders the alcoholic solution alkaline, 

 and is not easily saponified. It has a strong balsamic odor, and seems to contain 

 the odoriferous portion of the wax. 



Specific gravity. This is obtained by diluting alcohol until a drop of the wax, pre- 

 viously melted and cooled on glass, would float indifferently in it. By taking the 

 specific gravity of the alcohol that of the wax was found. The average gravity of 

 five samples of pure wax was 0.9547. Melting point was determined by several 

 methods : First, by placing a drop previously melted and cooled on glass or any smooth 

 surface on a volume of mercury and gradually heating by means of a steam or water 

 bath ; the instant the wax was seen to liquefy the temperature indicated by a ther- 

 mometer previously placed in the mercury was noted. Second, by means of a thin 

 glass tube, drawn out to a small opening, the finger was placed over the large end and 

 the small end dipped just below the surface of the melted wax, removed, and the thin 

 cap allowed to thoroughly cool. The tube was then partially filled with water, say 

 from 1 to 3 cc, according to the diameter and size of the lower opening. This tube 

 thus prepared was fastened to a thermometer by means of two rubber bands, so that 

 the cap of wax and the thermometer bulb were on the same level. This was placed 

 in a water bath and gradually raised to the temperature. Care was taken to have 

 the water level of the tube above that of the bath (but not so much above that the 

 pressure would break the cap of wax) until it was thoroughly fused. It was found 

 that a tube one-quarter inch in diameter gave the best results when 2.5 cc. of water 

 were placed in it and the water level kept 1.5 inches above that in the bath. When 

 the water in the tube was seen to lower the thermometer was read. A third method 

 was by means of a thin tube drawn out to a long point and filled with melted wax. 

 When cold the point was broken off and the tube fastened to a thermometer, the same 

 as in the previous case. The whole was so placed in cold water that the wax was 

 about an inch below the surface. The water was now gradually heated until the 

 pressure of the water forced the wax up in the tube. This was the time to read 

 the thermometer. The last method was to dip a thermometer bulb in melted wax 

 and remove, care being taken that the thermometer bulb should not be too cold, 

 else too thick a coating would be formed. After this thin film of wax was thoroughly 

 cooled, the thermometer was suspended in water and gradually heated until the wax 

 became transparent and liquid and then the thermometer read. 



The average fusing point of pure wax (5 samples) was found by these four methods 

 to be 62.6 C. 



