50 TECHNICAL DRUG STUDIES. 



eeminormal alcoholic potash and heat the mixture for at least three hours over a direct 

 flame with a reflux condenser. The excess of potassium hydroxid is determined with 

 seminormal hydrochloric acid. A blank with the alcoholic potash should be run. 



Stearic acid Boil 1 gram of the wax for several minutes with 15 cc of 80 per cent 

 alcohol, allow to cool to between 18 and 20 C., filter into a 200 cc cylinder, and dilute 

 filtrate with water to about 200 cc. If stearic acid is present, it separates into flakes 

 and collects at the surface. The test is sensitive to 1 per cent. If from 7 to 8 per cent 

 are present, a thick, creamy mixture results. 



Resin. Method I: Keep at the boiling point for about one minute a mixture of 5 

 grams of the wax and 20 to 25 cc of nitric acid (specific gravity, 1.32 to 1.33), dilute with 

 an equal volume of water and render slightly alkaline with ammonium hydroxid. 

 The solution decanted from the separated wax in the absence of resin is of a yellowish 

 color, while its presence produces a more or less intense reddish-brown coloration. 



Method II: Heat 1 gram of wax for a few minutes with 25 cc of 50 per cent alcohol 

 (alcohol of this strength will not extract stearic acid if present); cool and filter; evapo- 

 rate the filtrate to dryness on a water bath and add 5 cc acetic anhydrid. Heat to 

 boiling, cool, and then carefully allow sulphuric acid (specific gravity, 1.53), to flow 

 into the solution. The presence of the minutest quantity of resin will develop a fine 

 violet (fugitive) color. 



Detection and estimation of paraffin. The following method is the only one by which 

 paraffin can be detected with certainty: Melt from 2 to 5 grams of the wax in a porce- 

 lain dish, then add an equal weight of finely powdered potassium hydroxid, continue 

 heating for a few moments with thorough stirring. Cool and powder the hard mass, 

 and mix the resulting powder with three times as much potash lime as wax used, 

 then introduce this mixture into a thick-walled tube, immerse in an oil bath, and 

 heat to about 250 C. for from three to four hours. After cooling, finally powder the 

 tube with'its contents, place the mass in a Soxhlet apparatus, and extract with petro- 

 leum ether for several hours. The petroleum ether is evaporated and the residue 

 dried at 110 C. and weighed. By this treatment the esters are converted into 

 alcohols, and these alcohols on heating with potash lime are in turn converted into 

 their respective acids, while the hydrocarbons present are not affected and are 

 extracted with petroleum ether. Pure beeswax contains naturally from 12.5 to 14 

 per cent of hydrocarbons, and any adulteration with paraffin or allied bodies will 

 increase this percentage. 



TJie Henriques a cold saponification method. This method was 

 found very satisfactory. The wax is dissolved in high-boiling-point 

 (100 to 150 C.) petroleum ether, alcoholic potassium hydroxid is 

 added in excess, and the whole, after being warmed on the water 

 bath, is allowed to stand twenty-four hours, when the excess of 

 potassium hydroxid is titrated with seminormal hydrochloric acid, 

 phenolphthalein being used as indicator. 



The methods of the United States Pharmacopeia for testing bees- 

 wax are on the whole unsatisfactory. The carbonization of wax with 

 sulphuric acid for detecting paraffin is unwieldy, disagreeable, and 

 unreliable. Small amounts of paraffin can not be detected with any 

 degree of certainty by this method. Again, the method for saponi- 

 fying beeswax by heating on the water bath for one-half hour with 

 alcoholic potassium hydroxid is uncertain. 



oZts. angew. Chem., 1895, 81: 721 ; (Abst.) Analyst, 1896, 21: 192. 



