90 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



an extremely thin membrane, not easily seen except where it becomes 

 thick, and just under the testa in the heart of the crease. It is not of 

 importance from a milling point of view. The testa and tegmen form 

 about 2 per cent, of the grain. 



The embryous membrane is a continuation of the embryo around the 

 endosperm or floury portion of the grain. It is composed of cells which 

 are often erroneously termed gluten cells, but the true gluten cells are 

 scattered through the endosperm. The cells of the embryous mem- 

 brane contain little or no gluten, and as they are a continuation of the 

 embryo, it must be nearly as undesirable to allow them in the finished 

 flour as the germ itself. 



The endosperm is by far the largest portion of the grain, and it is 

 that which is the object of all milling processes to separate from the 

 rest of the wheat and grind to flour. 



It consists of large cells containing the granules of starch and the 

 gluten. At the exterior, nearer the embryous membrane, it is much 

 harder than in the center and contains much more gluten. In all 

 methods of gradual reduction, therefore, the center is of course reduced 

 first, and, being very starchy, is only fit for a low-grade flour, while the 

 richest part of the endosperm, being harder and closely attached to the 

 tough bran coats, is to a certain extent lost, or so contaminated with 

 small pieces of the bran as to injure the color of the flour, furnishing 

 what is known as bakers' grades. 



By the old-fashioned low-milling process, or grinding between stones 

 placed very close together and bolting, it was impossible to obtain a 

 flour entirely free from contamination. The advance to high milling, 

 with stones far apart, allowing the middlings which were produced to 

 be purified before grinding to flour, was a step which made it possible 

 to make from winter wheat an excellent and pure flour. When, how- 

 ever, spring wheat, with its hard and brittle outer coats, became im- 

 portant commercially, it was necessary to resort to the roller methods 

 of milling, which, in conjunction with peculiar purifying machinery, 

 would furnish a flour free from all undesirable impurities. 



This process is so complete that an examination and chemical analy- 

 sis of the products are of great interest, as showing how the different 

 constituents of the grain are divided. It is unnecessary, however, to 

 describe the process itself, long accounts of which can be found in the 

 millers' journals of the day and in the Census of 1880, Yol. Ill, Statistics 

 of Agriculture. It is sufficient merely to know the names of the j)roducts 

 and the portion of the grain from which they come. 



The first series, consisting of seventy-two specimens, is from the mill 

 of 0. A. Pillsbury & Co., Minneapolis, Minn., known as the Pillsbury 

 "A." This mill, it may be of interest to know, is described in the cen- 

 sus report previously mentioned. It uses the " hard spring wheat," which 

 is grown in the JSTorthwest, and its products, therefore, are typical of 

 this particular variety. 



The second partial series is from the mill of Herr & Cissel, in George- 

 town, D. C, and the wheat used at the time the specimens were collected 

 was a mixture of Virginia "Fultz" and " LongberryP Their products 

 arc illustrative, therefore, of the effect of the roller process on Virginia 

 winter wheat. 



The third partial series consists of a few specimens resulting from 

 the milling of Ohio winter wheat by Warder & Barnett, of Springfield, 

 Ohio, by the same methods as the others. 



The Minnesota samples, being more numerous, will be taken up first. 



