of the machine which has since been called the purifier, which removed the
dirt and light impurities from the refuse middlings in the same manner that
dust and chaff are removed from wheat by a fanning mill. The middlings thus
purified were then reground, and the result was a much whiter and cleaner
flour than it had been possible to obtain under the old process of low
close grinding. This flour was called 'patent' or 'fancy,' and at once took
a high position in the market. The first machine built by La Croix was
immediately improved by George T. Smith, and has since then been the
subject of numberless variations, changes, and improvements; and over the
principles embodied in its construction there has been fought one of the
longest and most bitter battles recorded in the annals of patent litigation
in this country. The purifier is to-day the most important machine in use
in the manufacture of flour in this country, and may with propriety be
called the corner-stone of new process milling. The earliest experiments in
its use in this country were made in what was then known as the 'big mill'
in this city, owned by Washburn, Stephens & Co., and now known as the
Washburn Mill B.

"The next step in the development of the new process, also originating
in Minneapolis, was the abandonment of the old system of cracking the
millstone, and substituting in its stead the use of smooth surfaces on the
millstones, thus in a large measure doing away with the abrasion of the
bran, and raising the quality of the flour produced at the first grinding.
So far as we know, Mr. E. R. Stephens, a Minneapolis miller, then employed
in the mill owned by Messrs. Pillsbury, Crocker & Fish, and now a member of
the prominent milling firm of Freeman & Stephens, River Falls, Wisconsin,
was the first to venture on this innovation. He also first practiced the
widening of the furrows in the millstones and increasing their number, thus
adding largely to the amount of middlings made at the first grinding, and
raising the percentage of patent flour. He was warmly supported by Amasa K.