842 FOODS AND FOOD ADULTERANTS. 



specific gravity in the literature at my command. According to Malaguti,* ozokerite 

 consists of a mixture of two bodies similar to paraffin, one of which has a specific 

 gravity of 0.957 and melts at 90, while the other constituent, with a specific gravity 

 of 0.945, melts in the neighborhood of 75. Preliminary determination showed that the 

 specific gravity of wax (0.965 to 0.969) and commercial paraffin (0.869 to 0.877) lie wide 

 enough apart to enable quantitative determinations to be made on mixtures from 

 the specific gravity. Pure, that is to say, paraffin-free beeswax should sink in alcohol 

 of 0.961 specific gravity (33 per cent by volume Tralles or 15.8 Baum6, or 27.27 per 

 cent by weight). If it floats in alcohol of this strength it is very likely adulterated 

 with paraffin. 



In the manufacture of candles, when using solid fat acids, paraffin up to 20 per cent 

 is always added, and on the other hand, when manufacturing paraffin candles, stearic 

 acid is always added. As, according to the text-books, the specific gravity of pure 

 stearic acid is 0.956. it occurred to me that candles could be investigated by deter- 

 mination of specific gravity, but investigation has shown the contrary. The reason 

 for this is that under the name stearic acid, in the technical sense, is not found the 

 pure aeid, but a mixture of various bodies, different in composition and physical 

 properties according to the source of the original fat. This mass consists in part of 

 neutral bodies. Stearic acid made from tallow by lime gave the following specific 

 gravity : 



No. 1:0.954 No. 2: 0.962 No. 3: 0.958 



With other samples, made by means of sulphuric acid, subsequent determinations gave 

 0.892. 



DETERMINATION OP THE SPECIFIC GRAVITY OF WAXES, ETC.t 



Place in an accurately marked 50 cc. flask a weighed rod of the wax, about 1 to 1.5 

 cm long by 0.5 cm diameter, and allow water to flow into the flask from a bu- 

 rette till the water level reaches the mark. Fifty cc minus the burette reading 

 represent the volume occupied by the wax. The rod should be made to lie flat on 

 the bottom of the flask, so that the incoming water will force its ends against the 

 sides and prevent the end from rising above the mark. 



DETERMINATION OF PARAFFIN IN BEKSWAX.t 



A wax mixed with paraffin is found in the trade under the name of "purified wax." 

 The following method was tried on some of this product : 100 grams were heated 

 with 30 grams concentrated sulphuric acid to 177 for between fifteen and twenty 

 minutes, 100 cc. of water then added, and the whole allowed to cool. On the surface 

 was now found a layer of paraffin, which weighed 80 grams. On repeating the exper- 

 iment with a mixture of 20 parts of wax and 80 parts of paraffin, the same result was 

 obtained. Paraffin alone treated in the same way remained unaltered. Carbonized 

 particles adhering to the paraffin can be detached by remelting. Paraffin on cooling 

 contracts so strongly that the surface becomes concave; wax retains its horizontal 

 surface. 



Dieterich gives a table of the specific gravity of various mixtures ot wax and 

 paraffin. 



Sedua || tests wax for paraffin by shaving off thin layers of wax, covering them with 

 twenty times their weight of ether, aud allowing them to stand half a day. Paraffin 

 dissolves, but very little wax goes into solution. The ether is decanted, evaporated, 

 and the residue weighed. Five-sixths of the weight is calculated as paraffin. 



* Annal. de chim et de phys., 4, 63, 390. 



t A. Gawalowski, Oel u. Fettiudustrie ; Chem. Centralblatt, 1890, 11, 502. 

 t A. W. Miller in Zeit. des osterr. Apoth. Vereina, 1875, p. 49 ; abs. Fres. Zeit. f. a. 

 Chem., 1875, 200. 



$ Wagner's Jahresber, 1H82, 1028. 



|| Das Wachs und seine technische Verwendnng, 15. 



