118 THE MICROSCOPE. Aug. 



Microscopical Characteristics of Oatmeal. 



By M. a. DEROS, 



PARIS. 

 [From Le 3Iicrogrophe Preparateur.] 



[Ill a series of articles on "tlie Adulteration of Alimen- 

 tary and Industrial Matters," i:)ublished in recent num- 

 bers of this valuable periodical is a good description of 

 the microscopical characteristics of oatmeal.] 



In oats we arrive at corn provided with polyhedral 

 granulated starch. This character renders the mixture 

 of oatmeal with other meals very easy to recognize. 

 These adulterations after all are very rare. As starch 

 forms more than 80 p. c. of the total volume of the meal 

 it is always relatively easy to find some of the suspected 

 granules in the preparations. 



The starch grains of oats are often agglomerated and 

 in small ovoid masses, measuring from 50 to 60 microns 

 in their largest diameter. If these agglomerations are 

 examined with care, the starch grains are distinguished 

 very neatly and closely laid against each other, which 

 gives them a polyhedral form. These granules pre- 

 sent pretty clear angles. They are irregular and very 

 small, for their diameter varies from 3 to 9 microns ; 

 the average being 5 microns. The hilum is not visible and 

 the concentric layers are scarcely distinguishable. The 

 opening generally happens from the exterior to the inte- 

 rior, but here that character is without importance. 



In polarized light on a dark field, the oat starch is 

 scarcely visible. In lighting the field, it is impossible to 

 obtain the black cross of which we have spoken a propos 

 of wheat. Treated with potash, oatmeal presents a 

 characteristic appearance. The gluten cells, not so large 

 as those of wheat, are arranged in one row only. The al- 

 bumenoid matter they contain is in very small grains. 

 These cells do not present a blue coloration after treat- 

 ment with ether. 



