192 FOODS AND FOOD ADULTERANTS. 



of sugar oil tlie ash free organic matter of the pepper, while all the 

 adulterants gave less than 30 per cent., with the exception of those 

 which are starchy, as flours and meals. 



Kottger repeated this determination, showing that some other sub- 

 stances besides starch were inverted by the acid, and obtained the fol- 

 lowing results : 



Black pepper sugar equivalent 57.2 to 60.3 



White pepper sugar equivalent 59.6 to 74.4 



The Lampoug pepper gave only 41.70. Such great variations he con- 

 siders fatal to the method as a means of detecting adulterations. His 

 conclusions seem not entirely justified, as a review of Leuz's figures will 

 sho w. 



Lenz in his paper affirms that any extract determination is useless, 

 as with various adulterants the results may be very close to actual 

 pepper. Petroleum ether he shows to be unreliable, the amount of ex- 

 tract depending on the kind of extraction apparatus used. There cer- 

 tainly should be no difficulty of purely manipulative detail of this de- 

 scription, for if sufficient time is given the solvent will work the same 

 under all conditions, but not less than twenty hours' continuous extrac- 

 tion should be allowed, and it is not fair to generalize on an analysis 

 where the extraction was continued less than that time, the poor re- 

 sults being due only to a probable faultily manner of manipulation, as 

 we have met with no such trouble. 



Lenz's conclusions seem hardly just, and while there may be cases 

 where adulterants would not be detected by an extract determination, 

 in the majority it is a great assistance. Lenz also refers to the method 

 of separation of the powdered particles of pepper adulterants by means 

 of liquids of certain specific gravities, and pronounces it usuitable. He 

 prefers the treatment with iodine solution and the selection of the par- 

 ticles not blued for examination under the microscope as adulterants. 

 We have found it perfectly simple and desirable to use the method of 

 separation with sieves, and to examine the coarse powder, with or with- 

 out treatment, under the microscope, when, with a little experience, it 

 is easy to distinguish and recognize the source of particles not pepper 

 after a careful examination with high powers. 



He also casts doubt upon the value of an ash determination, and 

 owing to the great variations which be finds quoted as possible, recom- 

 mends calculating all results on an ash free basis. He, however, admits 

 that a carefully and properly cleaned pepper-corn will not usually con- 

 tain more than 6 per cent., and his strictures, therefore, do not seem to 

 be consistent. He places reliance only on the process of his own inven- 

 tion, determinations of sugar corresponding to the starch and other in- 

 vertible substances, with supplementary determinations of water and 

 ash and microscopic examination. His results were as follows : 



