9 o 



MICROSCOPICAL DIAGNOSIS. 



of an inch in diameter); they are round or cup-shaped, with flat- 

 tenings here and there, due to the pressure of neighboring grains. 

 The starch grains of tapioca are generally found floating in the 

 field singly, but in the growing root they are found compounded 

 of two, three, or four grains each. A distinct and large circular 

 nucleus is seen in fresh specimens. In dried specimens the nucleus 

 is marked by a distinct star or cross. Tapioca is adulterated with 

 rice, sago, and potato starch. Potato flour is frequently prepared 

 like pearl tapioca, and sold as such. Tapioca is used quite exten- 

 sively in England as an adulterant, but not so much in America. 



Fig. jf. Turmeric Starch. 



These starches, sago and tapioca, are so much changed in the dif- 

 ferent commercial varieties, /. <?., pearl, white, meal, etc., that to be- 

 come well acquainted with them one should examine each variety 

 carefully. An illustration or drawing of these in their fresh state 

 would hardly be of value in identifying the starch grains as we find 

 them in market as an adulterant. 



Turmeric Starch is from the rhizome of Curcuma longa, and 

 is imported principally from Southern Asia. The parenchyma is 

 packed full of starch in angular or roundish masses. Turmeric is 

 used extensively as a coloring material, to give deeper color to 

 the spices which have been adulterated with some of the flours. 

 When a ground spice, as, for example, mustard, contains turmeric, 

 even if not in large quantities, its presence can be detected by expos- 



