132 METHODS OF ANALYSIS [Chap. 



liquids is complete. Draw off as much as possible of the ether-fat solution (usually 

 0.5-0.8 cc. will be left) into a weighed flask through a small, rapid filter. The flask 

 should be weighed with a similar one as a counterpoise. Again extract the liquid 

 remaining in the tube, this time with 15 cc. each of ether and petroleum ether, shake 

 vigorously half a minute with each, and allow to settle. Proceed as above, wash- 

 ing the tip of the spigot and the filter with a few cc. of a mixture of equal parts of 

 the 2 ethers (previously mixed and free from deposited water). For absolutely 

 exact results the extraction must be repeated. This third extraction usually yields 

 not more than about 1 mg. of fat, if the previous ether-fat solutions have been 

 drawn off closely, or an amount averaging about 0.02% on a 4 gram charge. Evapo- 

 rate the ether slowly on a steam bath, then dry the fat in a boiling water oven until 

 the loss in weight ceases. Test the purity of the fat by dissolving in a little petro- 

 leum ether. Should a residue remain, wash the fat out completely with petroleum 

 ether, dry the residue, weigh, and deduct the weight. 



30 PARAFFIN IN CONFECTIONERY.-TENTATIVE. 



Add to the ether extract in the flask, as above obtained, 10 cc. of 95% alcohol 

 and 2 cc. of sodium hydroxid solution (1 to 1), connect the flask with a reflux con- 

 denser, and heat for an hour on the water bath, or until saponification is complete. 

 Remove the condenser and allow the flask to remain on the bath until the alcohol 

 is evaporated and the residue is dry. Dissolve the residue as completely as pos- 

 sible in about 40 cc. of water and heat on the bath, shaking frequently. Wash into 

 a separatory funnel, cool, and extract with 4 successive portions of petroleum ether, 

 which are collected in a tared flask or capsule. Evaporate the petroleum ether 

 and dry in the oven to constant weight. 



Any phytosterol or cholesterol present in the fat would be extracted with the 

 paraffin. The amount is so insignificant that it may be disregarded generally. 

 The character of the final residue should, however, be confirmed by determining 

 its melting point, specific gravity, and refractive index. 



31 ALCOHOL IN SmUPS USED IN CONFECTIONERY ("BRANDY DROPS").— TENTATIVE. 



Collect in a beaker the sirup from a sufficient number of pieces to yield 30-50 

 grams of sirup. Strain the sirup into a tared beaker and weigh. Introduce the 

 sirup into a 250-300 cc. distilling flask, dilute with half its volume of water, attach 

 the flask to a vertical condenser and distil almost 50 cc, or as much of the liquid as 

 possible without causing charring. Foaming may be prevented by adding a little 

 tannin, or a piece of paraffin about the size of a pea, to the contents of the distil- 

 lation flask. Cool the distillate, make up to volume with water, mix well, and 

 ascertain the specific gravity of the liquid by means of a pycnometer, and obtain 

 the corresponding weight of alcohol in the 50 cc. of distillate from XVI, 5. Cal- 

 culate the per cent by weight of alcohol in the candy filling. 



32 COLORING MATTER.— TENTATIVE, 

 Proceed as directed under XI. 



33 METALS.— TENTATIVE. 

 Proceed as directed under XII. 



