10 



ADULTERATED DRUGS AND CHEMICALS. 



COCHINEAL. 



AVAILABILITY OF THE PURE PRODUCT. 



it seems that the cochineal industry is grossly involved in adultera- 

 tion, and, according to some dealers, irretrievably lost to this practice. 

 They contend that it is almost impossible to purchase a pure article on 

 the open market, but an investigation shows that this contention is not 

 well founded. In fact, the pure product is so easily secured that adul- 

 terated cochineal would be placed under the fraudulent form of 

 adulteration if it were not well known that the consumer virtually 

 knows only the silvered or commonly adulterated variety. The object 

 of the work done on cochineal was to ascertain, not the extent of the 

 adulteration, but how difficult it is to obtain the pure article. It was 

 soon found that pure cochineal was readily available when demanded. 

 A number of samples examined gave the following results: 



Analyses of cochineal. 



Nos. 3 and 156 represent goods delivered to the Bureau of Chem- 

 istry without specification. No. 159 was sent with the belief that it 

 was adulterated. Nos. 157, 158, and 165 were delivered as pure goods, 

 and an examination proved such to be the case. On account of the 

 high price, the variable quality, and the customary adulteration of 

 cochineal, suitable methods for readily determining its quality are very 

 desirable. 



METHODS OF ANALYSIS. 



The per cent of ash is a fair index in determining the purity of cochi- 

 neal, but this factor can easily be circumvented by the addition of 

 starch, mixing exhausted material with the pure article, or molding 

 paste into small grains to resemble closely the outlines of the insects 

 themselves. The ash of normal cochineal should never exceed 6 per 

 cent. 



The most reliable procedure to determine the quality of cochineal 

 is to estimate the amount of carmine either oolorimetrically or by one 

 of the oxidation methods. J. Ijowontlml's" well-known method for 



"Xtsrli. anal. Chen... 1S77, 1(J: 179. 



