FERMENTED AND DISTILLED LIQUORS. 91 



(h) DETECTION OF ABRASTOL. 



(1) Sinabaldi's method.* 



Make 50 cc of the sample alkaline with a few drops of ammonia and extract with 

 10 cc of amyl alcohol (ethyl alcohol is added if an emulsion be formed). Decant 

 the amyl alcohol, filter if turbid, and evaporate to dryness. Add to the residue 2 cc 

 of a mixture of equal parts of strong nitric acid and water, heat on the water bath 

 until half of the water is evaporated, and transfer to a test tube with the addition of 

 1 cc of water. Add about 0.2 gram of ferrous sulphate and an excess of ammonia, 

 drop by drop, with constant shaking. If the resultant precipitate be of a reddish 

 color, dissolve it in a few drops of sulphuric acid, and add ferrous sulphate and 

 ammonia as before. As soon as a dark-colored or greenish precipitate has been 

 obtained, introduce 5 cc of alcohol, dissolve the precipitate in sulphuric acid, and 

 shake the fluid well and filter. In the absence of abrastol this method gives a color- 

 less or light-yellow liquid, while a red color is produced in the presence of 0.01 gram 

 of abrastol. 



(2) Sangte-Ferrre b method. 



Boil 200 cc of wine with 8 cc of concentrated hydrochloric acid for one hour in a flask 

 with reflux condenser attached. Abrastol is thus converted into beta-naphthol and 

 is detected as directed under (g) . 



(i) BORIC ACID. 



Boric acid is a normal constituent of wine and its qualitative detection in wine is 

 therefore of little value unless a very heavy reaction is obtained. For methods of 

 detection and estimation, see page 110. 



(j) DETECTION OF FLUORIDS. 



(1) Firxt method. 



Heat to boiling about 100 grams of wine, made slightly alkaline with ammonium 

 carbonate and precipitate the fluorin with 2 or 3 cc of an approximately 10 per 

 cent solution of calcium chlorid. Continue the boiling for five minutes, separ- 

 ate the precipitate by filtration, wash with a little water, dry, and ignite in a 

 platinum crucible. Add 1 cc of strong sulphuric acid, cover the crucible with 

 a watch glass coated with paraffin or wax, with a character marked through the wax 

 so as to permit the watch glass to be etched at some point, and heat on a water bath 

 for an hour at a temperature of from 75 to 80 C. One milligram can be readily 

 detected by this method. The delicacy of the method is impaired by the presence 

 of a small amount of silica in the ash of the wine. 



(2) Second method. 



If it is desired, the preceding method may be varied by mixing a small amount of 

 precipitated silica with the precipitated calcium fluorid and placing it in a crucible 

 covered by a watch glass which is not coated with paraffin, and to which a drop of 

 water is suspended on the underside. Add 1 cc of concentrated sulphuric acid to the 

 crucible, and heat for an hour at the temperature of 70 or 80 C. The silicon fluorid 

 which is formed is decomposed by the water, leaving a gelatinous deposit of silica, 

 while a ring is frequently etched at the circumference of the drop of water. Any 

 fluosilicates and llnoborates present will also be indicated by this reaction. 



MOD. Sri.. 1M:', [ I] . 7, M-J. o Neviere and Hubert, Mon. Sci., 1895 [A], 9, 324. 



1 cunil>. ivmi. i.v.i:;. 1 17, y:5. 



