520 



Gleanings in Bee Culture 



m@D°a}D ©®cp[p®©^®Di]d]®[ii]©(i 



PURITY TESTS FOR BEESWAX. 



II. — Physical Tests. 



BY WM. P. HUNGER. 



Continued from last issue. 



The chemical methods given in the ]irevi- 

 ous article are used more frequently to as- 

 certain the nature of an adulterant than 

 they are merely to test for the presence of 

 an adult-erant. The most common cominer- 

 cial method for detecting the presence of the 

 ordinary adulterants in beeswax is the "ti- 

 ter test," first proposed by Dalican in 1868, 

 and which depends on two facts. The first 

 fact is that, as a substance changes from the 

 liquid to solid, heat is given off. This may 

 be easily proven by introducing the bulb of 

 a previously warmed thermometer into the 

 wax when melted to a thin flu- 

 id, and allowing the dish and 

 charge to cool slowly. The fall 

 of temperature will be quite 

 regular at first, but abruptly 

 mercury will cease to fall; and 

 if the mass was superfused, that 

 is, cooled below its freezing- 

 point, the mercury will rai)idly 

 rise to indicate the true freezing- 

 jioint of the wax, the temper- 

 ature will remain at that i)oint 

 for some little time and then 

 begin to fall regularly until 

 room temperature is reached. 

 As the rate of radiation from the 

 dish and charge was continu- 

 ous and decreasing, heat must 

 have been obtained from the 

 only source jiossible, the charge 

 itself, to maintain the constant 

 temperature. If the thermom- 

 eter was read every fifteen sec- 

 onds, and the readings plotted, 

 a curve such as shown in Fig. 

 1 would be obtained. In the 

 figure the horizontal lines rep- 

 resent an increase of 5° F., from 

 the bottom up, and the vertical 

 lines an increase of two minutes 

 from the left. The maximum 

 point A in Fig. 1, reached in 

 the short rise after the mercury 

 first ceased to fall, is the solidi- 

 fication temperature, or "titer." 



The second fact is that, while 

 the titer is always the same for 

 the same i)ure wax or fat, the 

 addition of even a small propor- 

 tion of another fat or wax to the 

 pure fat or wax will cause a de- 

 pression of the titer, the amount 

 of depression varying with the 

 mixture. Fig. 2 shows the 

 curve for beeswax-paraffin com- 

 l^ounds, the horizontal lines in- 

 dicating differences in temper- 



op- 



/eo 



/T'O 



/60 



/SO 



/^O 



/SO 



/20 



/JO 



ature as in Fig. 1, and the vertical lines in- 

 dicating differences of 10 per cent paraffin 

 in the mixtures. 



An inspection of Fig. 2 would lead one to 

 suppose that, by using wax of higher titer 

 than beeswax, a mixtvire could be made 

 which would have the same titer as beeswax. 

 Carnauba wax, Chinese insect wax, and 

 some few others have a higher titer than 

 beeswax, and can be so used; but as these 

 waxes would alter the specific gravity and 

 other projjerties of the beeswax, a third sub- 

 stance would have to be added as corrector, ' 

 which third substance would be detected by 

 the chemical tests already given. Further- 

 more, if a cooling curve is plotted for each 

 saniple on which the titer is taken, a little 

 experience will enable one to detect such a 

 mixture by the abnormal form of the curve. 



To make a titer test, take a test-tube 



Z ^ <s B /o /a. /i^ /6 /8 ^o 

 7~/'/ne /// Afi/jutes 



F/'g.7~^Coo/j/?Q Curve of 



Bee^ wax 



