298 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



it is not only easy to detect the presence of foreign matter, but io 

 identify tlie sonrce. In the pecnhar form and properties of the vari- 

 oiis starches we find a great aid, inasmuch as many of the spices con- 

 tain no starch, and tlie presence of any at once shoAvs that some for- 

 eign substance containing it has been added. Other spices contain 

 starcli, but of such distinctive form and character that it is not easily 

 confused with that of adulterants. The elements of which the 

 structure of fhe berry, the bark, the pod, or whatever jDart of the 

 plant may be used as a spice, are composed are also distinctive, and 

 the arrangement of the different kinds of vegetable cells more or less 

 characteristic of each spice and distinct from its adulterants. For 

 all this examination it is of course necessary to have for reference 

 specimens of well-authenticated spices, whole and ground, and of the 

 common starches and adulterants. In our special bulletin an attempt 

 has been made from our own experience and that of others to describe 

 the most characteristic points m the structures which are met with. 



Although the microscope is the most convenient and ready means 

 of determining the character of a ground spice, in all cases of impor- 

 tance, where a question of the sale of adulterated articles is involved, 

 resort for confirmation should be had to chemical analysis. Unfor- 

 tunately, this method of investigation is not as available as the micro- 

 scope, requiring greater facilities and skill, and consuming much 

 longer time. It has not, in addition, received that amount of atten- 

 tion which it should have done, and in consequence the standards of 

 purity are not as well fixed as they should be. 



The results of a study of this side of the subject will be presented 

 in the special bulletin of this division which has been referred to. 



Considering the spices individually as they are met with, both pure 

 and in the trade, there are certain peculiarities which should not be 

 overlooked. 



MUSTARD. 



Mustard, ag sold in the ground state, should be the farina or flour 

 of the black or white mustard seed; that is to say, the flour from the 

 interior of the seed, bolted or separated from the hulls. The two 

 kinds of seed, although derived from plants of the same genus, are 

 somewhat different in their chemical composition. The black seed 

 is much the most pungent, and develops on mixing with water a vola- 

 tile oil which gives this condiment its penetrating character. There 

 is also present in the seed complicated organic substances of a bitter 

 nature, to which is due also some of the peculiar flavor, and while the 

 white seed forms no volatile oil with water, it contains more of this 

 bitter substance. It is, therefore, very common to mix the two in 

 grinding. The sources of the seed are various. In our markets at 

 present there are quoted California black and white, Dutch, Trieste 

 black, and English, the last being the most valuable. 



In the manufacture of the seed into flour for the market two cus- 

 toms have arisen which change the nature of the original substance, 

 and therefore would commonly come under the head of adulteration. 

 One is extremely old, the addition of flour for the purj^ose of making 

 the condiment keep better. This necessitates the restoration of the 

 yellow color by turmeric. Both of these diluents are harmless, but 

 there seems to be no reason for their uae, and it is gradually becom- 

 ing commoner to find mustard free from them in English brands. 



The other custom is the abstraction of the fixed oil by pressure be- 



