FOOD AND FOOD ADULTERANTS. 



sent both tho chloroform and ammoniacal liquid will be colorless. In presence of 

 quassiin tho ammouia will be colored a bright yellow. 



The chloroform residues from camomiles, calnmba, colocynth, cocculus, and chi- 

 retta do not give any similar reactions with bromine and ammonia. The ether residue 

 from chiretta gives a straw-yellow coloration, gradually changing to a dull purplish 

 brown, but the fact that no such reaction yielded by the chloroform solution of 

 the drug renders confusion with quassia impossible. Picric acid yields a solution in 

 chloroform which is but slightly colored compared with the deep-yellow liquid pro- 

 duced on subsequent agitation with ammouia; but if its presence be suspected it 

 can be readily and completely removed by agitating the chloroformic solution with 

 soda or ammonia, and separating the alkaline liquid before employing bromine. 



With a view of ascertaining how far the foregoing reactions of quassiiu were 

 likely to be of service in practice I added to one liter of a mild beer, which had been 

 previously proved to yield no bitter principle to chloroform after treatment with ace- 

 tate of lead, sufficient infusion of quassia to make a perceptible difference in the 

 flavor. The liquid was concentrated, precipitated Avith neutral lead acetate, the 

 filtrate treated with sulphuretted hydrogen, and the refiltered liquid further concen- 

 trated and agitated with chloroform. On evaporating the chloroform a residue was 

 obtained which had an intensely bitter taste, and yielded a solution which gave a 

 white precipitate with tanuiu, but did not reduce ammouio-nitrate of silver. The 

 residue gave no color on warming with concentrated sulphuric acid, but gave a \vell- 

 developed mahogany-brown color with ferric chloride. By tho bromine and am- 

 monia test it gave a strong yellow coloration. 



The amount of residue obtained would have sufficed to obtain all these reactions 

 several times, so that it may be considered established that quassia can be detected with 

 certainty and facility in a moderate quantity of beer containing it. 



The employment of chiretta as a hop substitute has been repeatedly recorded by 

 previous observers, but no tests are given for it by Dragendorff or others who have 

 worked on the subject. I found it in quantity in two hop substitutes I recently ex- 

 amined, and suspect its presence in a third. The active principle (chiratiu, C-.HiJ >, , i 

 is intensely bitter, sparingly soluble in cold water, rather more so in hot, and is 

 readily dissolved by alcohol and ether, the latter sol vent readily removing it from its 

 aqueous solution. Ou the other hand, chloroform removes but little bitter principle 

 from an aqueous infusion of chiretta. Chiratin is a neutral substance, decomposed 

 by dilute acids into ophelic acid and chiratogeuin. It does not reduce Fehling's so- 

 lution, gives a copious precipitate with tannin, and is not precipitated by neutral 

 lead acetate. The reaction of the other residue from infusion of chirelta with bro- 

 mine and ammonia has already been described. 



It is evident that our knowledge of the chemistry of the vegetable bitters availa- 

 ble as hop substitutes is very incomplete, and it is only by its further study we can 

 hope to fully solve tho problem of their detection in beer. But I believe we can 

 already distinguish with certainty and facility between "hops" and " not hops," 

 and that ought to suffice in many cases. When we examine butter we are content 

 to define the admixture as " foreign fat," and we make no attempt to specify the 

 exact nature or origin of the foreign fat employed. I submit that wo are fully able 

 to take a similar position with respect to hops and hop substitutes. 



The following are some of the remarks made in the discussion of this 

 paper : z 



Dr. Adams said that ho worked on the question of hop substitutes some ten or 

 twelve years ago, and he found no difficulty in distinguishing between the, bitter of 

 hop and the substitutes used for it. The method ho found most useful \v:is the pie 

 cipitation by subacetate of lead, and there was no dilliculty at all with the ordinary 

 bitters such as quassia, ealmnha, gentian, eliiretta, and worm wood, all remaining in 



7 /</,/., ]). II I. 



