MALT LIQUORS. 303 



SALICYLIC ACID IN SAMPLES EXAMINED BY THIS DIVISION. 



Out of thirty two samples analyzed by this Division I found seven to 

 contain salicylic acid in sufficient quantities to admit of qualitative 

 proof, or nearly one fourth of the entire number analyzed. The serial 

 numbers of these beers corresponding to those in the large table on page 

 282 are as follows: 4S01-3-5-G-1 7-23-25. These were all bottled beers, 

 one being an imported (Kaiser) beer. None was found in any of the draft 

 beers. Of the nineteen samples of American bottled beers, six contained 

 salicylic acid, or nearly one third. These included the product of some 

 of the largest breweries in the country, beers that are used to a very large 

 extent all over the United States. Whether the acid is added in the 

 breweries where the beer is made, or whether it is used by the local 

 bottlers, I am unable to decide. In one case I found it in the beer sold 

 here under the brand of a large Western brewery, and sent direct to 

 the same brewery for another sample, which gave no test for the acid ; 

 unfortunately I cannot be sure in this case that the firm in question did 

 not know the purpose for which the sample was intended. 



DETECTION AND ESTIMATION OF SALICYLIC ACID. 



Fortunately we have a particularly delicate and characteristic test for. 

 this substance, by means of which its presence can be detected in the 

 minute quantity of 1 part to 100,000. This is the well-known charac- 

 teristic violet color it gives with ferric salts. The test can sometimes 

 be applied directly in the case of very clear beers, but in most samples 

 it is obscured, either by the original color of the solution, or by the color 

 produced by the combination of the iron with other constituents of the 

 liquid. There are various procedures given for the separation of the 

 salicylic acid from these constituents, so as to apply the test to it when 

 in a pure state. Bias l has investigated various methods, including the 

 previous precipitation of the beer with lead acetate, and the removal o* 

 the excess of lead with sulphuric acid ; 2 shaking out the acidified solu- 

 tion with ether, evaporation of the ether and testing of the residue; 

 treatment with bone-black, washing out the latter with alcohol and ap- 

 plying the test to the alcoholic solution; none of which methods, ho 

 thinks, gives so good results as the application of the test to the urine 

 of a person who has drank some of the beer in question. By this 

 peculiar method of making the human body a medium of separation, ho 

 claims to make the test five times as delicate as where it is applied 

 directly to the beer. Borntrager 3 arrived at similar conclusions, and I 

 can testify myself to its superior delicacy to the direct application to the 

 beer. Muter 4 was probably the first to use dialysis for the separation, 

 also recommended by Aubry. 5 Portele 6 precipitates the tannin, &c., by 

 a solution of gelatine and shakes up the filtrate with ether. Weigert 7 uses 



1 Jour. prak. Chem., 19, 43. 6 Zeit. Anal. Chem. 1880, 105. 



2 E. Robinet, Compt., rend. 84, 1321. 6 Weiulanbe 1879, 389. 



3 Zeit. Anal. Chem. 1881, 87. 7 Zeit. Anal. Chem. 1880, 45. 

 'The Analyst 1, 193. 



