MALT LIQUORS. 305 



to the other .005 grams. These two samples were then subjected to 

 treatment by eight dilt'erent methods, as follows : 



(1) Extracted with chloroform. 



(2) Extracted with ether simply. 



(3) Extracted with ainyl alcohol. 



(4) Extracted with ether after previous precipitation with lead subace- 



tate. 



(5) Extracted with ether after previous precipitation with gelatine. 



((!) Extracted with ether after previous precipitation with ferric chlo- 

 ride. 



(7) Extracted with equal parts of ethylic and petroleum ether. 



(8) Extracted with ether, the solution allowed to evaporate sponta- 



neously, and the residue extracted with benzine. 

 These tests, tried on the beer containing .05 grams to the liter, gave 

 results which ranged them in the followiug order of succession, accord- 

 ing to the strength and brilliancy of the test: 8, 5, 7, 6, 2, 1, 4, 3. In 

 methods 5 and the length of time required to filter the solutions con- 

 stitutes an objection to their use. The same tests applied to the beer 

 containing .005 grams to the liter gave the test only in the case of Nos. 

 8 and 7, the former being the better of the two. The same series of 

 tests were applied to a red wine, with very similar results, so I have 

 adopted method No. 8 in all the work done on beers and wines, and 

 would recommend either that or No. 7, both of which give a perfectly 

 bright, water-clear solution, in which the slightest tinge of violet color- 

 is plainly visible. 



QUANTITATIVE ESTIMATION. 



While the qualitative determination of salicylic acid is so delicate and 

 easy of execution, the quantitative estimation is unfortunately a tedious 

 and unsatisfactory operation, in the small quantities in which it is 

 found. This is an argument in favor of the entire prohibition of its use 

 in foods in preference to the restriction of the quantity to be used. 



The determination may be made by the same method as described 

 above for the qualitative test, simply making the extraction complete. 

 One hundred cubic centimeters of the beer or wine are taken, acidified 

 with a few drops of hydrochloric acid, and extracted with three succes- 

 sive portions of ether of 50cc. each ; these are mixed and the whole 

 allowed to evaporate spontaneously. The residue from this evapora- 

 tion is heated for an hour on the water bath to drive off volatile acids, 

 and treated with loOcc. of pure benzine, which is allowed to stand in 

 contact with the residue for twenty-four hours, when it is drawn off care- 

 fully and the residue again treated with 50cc. of benzine, which is added 

 to the first portion. This 200cc. of benzine is then made up to SOOcc. 

 with absolute alcohol, and titrated directly with a decinormal solution 

 of soda, previously standardized by operating upon a similar mixture. 



