MKTHODS <>K ANALYSIS. 41 



SIMPLE TESTS FOR THE DETECTION OF FOOD ADULTERANTS. 



INTRODUCTION. 



Generally speaking, the methods of chemical analysis employed in 

 food laboratories <*an he manipulated only by one wlio has had at leaM 

 the usual college course in chemistry, and ->ome special training in the 

 examination of foods is almost as necessary. Again, mo^t of the 

 apparatus and chemicals necessary are entirely beyond the reach of 

 the home, and the time consumed by the ordinary examination of a 

 food is in itself prohibitive. 



Vet there are some simple tests which serve to point out certain 

 forms of adulteration and can be employed by the careful housewife 

 with the reagents in her medicine closet and the apparatus in her 

 kitchen. The number may be greatly extended by the purchase of a 

 very few articles that m&y be procured for a few cents at any drug- 

 store. In apph r ing these tests, one general rule must always be kept 

 carefully in mind. Every one, whether layman or chemist, must 

 familiarize himself with a reaction before drawing any conclusions 

 from it. For instance, before testing a sample of supposed coffee for 

 starch, the method should be applied to a sample of pure coffee (which 

 can always be procured unground) and to a mixture of pure coffee and 

 starch prepared by the operator. 



Many manufacturers and dealers in foods have the ordinary son-e- 

 so highly developed that by their aid alone they can form an intelli- 

 gent opinion of the nature of a product, or of the character, and 

 sometimes even of the proportion, of adulterants present. This is 

 especially true of such articles as coffee, wine, salad oils, flavoring 

 extracts, butter, and milk. The housewife finds herself constantly 

 submitting her purchases to this test. Her broad experience develop* 

 her senses of taste and smell to a high degree, and her discrimination 

 is often sharper and more accurate than she herself realizes. The 

 manufacturer who has developed his natural senses most highly 

 appreciates best the assistance or collaboration of the chemist, who 

 can often come to his relief when his own powers do not avail. So 

 the housewife, \>y a few simple chemical tests, can broaden her Held 

 of vision and detect many impurities that are not evident to the sen- -. 



There are here given methods adapted to this purpose, which may 

 be applied to milk, butter, coffee, spices, olive oil, vinegar, jams and 

 jellies, and flavoring extracts. In addition to this some general meth- 

 ods for the detection of coloring matter and preservatives will be 

 given. All of the tests here described may be performed with uten- 

 sils found in any well-appointed kitchen. It will be convenient, how-' 

 ever, to secure a small glass funnel, about 3 inches in diameter, since 

 filtration is directed in a number of the methods prescribed. Filter 

 paper can best be prepared for the funnel by cutting a circular piece 



