188 FOODS AND FOOD ADULTERANTS. 



mustard hulls, yellow corn, cracker dust, charcoal, and mineral matter 

 have been detected by their characteristic appearances. The presence 

 of pepper husks and charcoal is generally known by the immensely in- 

 creased proportion of black particles in the field, as appears in Fig. 43, 

 Plate XVII. A careful sorting of the coarser particles tin der a low power 

 of the dissecting microscope and selection, for example, of the shining 

 white grains of rice or yellow particles of corn from the more oily pepper 

 cells, enables us to examine the starches separately with plain and polar- 

 ized light. The appearance of the true pepper powder and one in 

 which rice starch is present is given in Plate XXII, Figs. 43 and 44. 

 Pepper starch is so much smaller than any other which we meet with, 

 that it is not easily confused with it. Fig. 65, Plate XXVIII, gives an 

 idea of its size as compared with others. With the dissecting micro- 

 scope it is also convenient to go over the pepper powder and pick out 

 any other class of suspicious particles for examination with higher power. 

 With a little practice it soon becomes easy to tell an adulterated speci- 

 men even with a cursory examination with a lower power or a hand lens. 

 In this way, in our experience, one or two foreign substances have been 

 found which have not been identified, but which were evidently parts 

 of the husks or coverings of some seed or fruit. The shell of the cocoa- 

 nut, as has been said , has not been met with as an adulterant, but it is 

 not at all difficult to identify, as its structure, with its innumerable 

 stone cells and fibrous tissue, is very characteristic after treatment witli 

 Schulze's reagent. 



The microscopic examination thus gives very certain indications of 

 the quality of peppers, although frequently the eye with out aid will 

 detect a fictitious appearance. The chemical examination, on the other 

 hand, as will be shown, serves as a reliable means of confirmation in 

 many instances, and gives evidence of the quantity as well as kind of 

 the adulteration. A considerable amount of information has been ac- 

 cumulated in regard to the proximate composition of peppers. Fliick- 

 iger quotes authorities for the statement that black pepper contains 

 from 1.6 to 2.2 per cent, of volatile oil, of the character of a terpeue and 

 optically active; also a nitrogenous substance known as piperine to 

 the extent of 2 to 8 per cent. Husemann and Hilger* give reference to 

 papers byjseveral investigators (seebiobligraphy), and describes piperine 

 as soluble in alcohol, and less so in ether. This substance, which is 

 characteristic, will be found, therefore, in the ether extract of the spice, 

 together with the volatile oil. 



Blyth has made an examination of several peppers, and gives results 

 which are useful for reference. 



Die Pflanzenstoffe, B. 2, S. 486. 



