Scientific American Supplement No. 275

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I make a distinction here as is seen, between the action through being
present, and the action of real ferments, but it is not my intention to
approve or disapprove of the different opinions expressed on this subject.
I make use of these expressions only to explain more clearly the phenomena
I have to speak of, for it is our duty to bear in mind that the real
ferments only act after a longer or shorter period of development, while,
on the other hand, the effects through presence are immediate.

I now return to the embryous membrane. Various causes increase or decrease
the action of this tissue, but it may be said in general that all the
agents that kill the embryous membrane will also kill the cerealine. This
was the reason why I at first attributed the production of dark bread
exclusively to the latter ferment, but it was easy to observe that during
the baking, decompositions resulted at over 158 deg. Fah., while the cerealine
was still coagulated, and that bread containing bran, submitted to 212 deg. of
heat, became liquefied in water at 104 deg.. It was now easy to determine
that dark flours, from which the cerealine had been removed by repeated
washings, still produced dark bread. It was at this time, in remembering
my experiences with organic bodies, I determined the properties of the
insoluble tissue, deprived of the soluble cerealine, with analogous
properties, but distinguished not alone by its solid organization and state
of insolubility, but also by its resistance to heat, which acts as on
yeast. There exists, in reality, I repeat, a resemblance between the
embryous membrane and the yeast; they have the same immediate composition;
they are destroyed by the same poisons, deadened by the same temperatures,
annihilated by the same agents, propagated in an analogous manner, and
it might be said that the organic tissues endowed with life are only an
agglomeration of fixed cells of ferments. At all events, when the blades of
the embryous membrane, prepared as already stated, are exposed to a water
bath at 212 deg., this tissue, in contact with the diluted starch, produces
the same decomposition; the contact, however, should continue two or three
hours in place of one. If, instead of placing these membranes in the water
bath, they are enveloped in two pounds of dough, and this dough put in the
oven, after the baking the washed membranes produce the same results, which
especially proves that this membrane can support a temperature of 212 deg. Fah.
without disorganization. We shall refer to this property in speaking of the
phenomena of panification.

CEREALINE.--The cells composing the embryous membrane contain, as already
stated, the cerealine, but after the germination they contain cerealine and
diastase, that is to say, a portion of the cerealine changed into diastase,
with which it has the greatest analogy. It is known how difficult it is to
isolate and study albuminous substances. The following is the method of
obtaining and studying cerealine. Take the raw embryous membrane, prepared
as stated, steep it for an hour in spirits of wine diluted with twice its
volume of water, and renew this liquid several times until the dextrine,
glucose, coloring matters, etc., have been completely removed. The
membranes should now be pressed and cast into a quantity of water
sufficient to make a fluid paste of them, squeeze out the mixture,
filter the liquid obtained, and this liquid will contain the cerealine
sufficiently pure to be studied in its effects. Its principal properties
are: The liquid evaporated at a low temperature produces an amorphous,
rough mass nearly colorless, and almost entirely soluble in distilled
water; this solution coagulates between 158 deg. and 167 deg. Fah., and the
coagulum is insoluble in acids and weak alkalies; the solution is
precipitated by all diluted acids, by phosphoric acid at all the degrees of
hydration, and even by a current of carbonic acid. All these precipitates
redissolve with an excess of acid, sulphuric acid excepted. Concentrated
sulphuric acid forms an insoluble downy white precipitate, and the
concentrated vegetable acids, with the exception of tannic acid, do not
determine any precipitate. Cerealine coagulated by an acid redissolves in
an excess of the same acid, but it has become dead and has no more action
on the starch. The alkalies do not form any precipitate, but they kill the
cerealine as if it had been precipitated The neutral rennet does not make
any precipitate in a solution of cerealine--5 centigrammes of dry cerealine
transform in twenty-five minutes 10 grammes of starch, reduced to a paste
by 100 grammes of water at 113 deg. Fah. It will be seen that cerealine has a
grand analogy with albumen and legumine, but it is distinguished from them
by the action of the rennet, of the heat of acids, alcohol, and above all
by its property of transforming the starch into glucose and dextrine.

It may be said that some albuminous substances have this property, but it
must be borne in mind that these bodies, like gluten, for example, only
possess it after the commencement of the decomposition. The albuminous
matter approaching nearest to cerealine is the diastase, for it is only a
transformation of the cerealine during the germination, the proof of which
may be had in analyzing the embryous membrane, which shows more diastase
and less cerealine in proportion to the advancement of the germination: it
differs, however, from the diastase by the action of heat, alcohol, etc.
It is seen that in every case the cerealine and the embryous membrane
act together, and in an analogous manner; we shall shortly examine their
effects on the digestion and in the phenomena of panification.

PHOSPHATE OF CALCIUM.--Mr. Payen was the first to make the observation
that the greatest amount of phosphate of chalk is found in the teguments
adjoining the farinaceous or floury mass. This observation is important
from two points of view; in the first place, it shows us that this mineral
aliment, necessary to the life of animals, is rejected from ordinary bread;
and in the next place, it brings a new proof that phosphate of chalk is
found, and ought to be found, in everyplace where there are membranes
susceptible of exercising vital functions among animals as well as
vegetables.

Phosphate of chalk is not in reality (as I wished to prove in another work)
a plastic matter suitable for forming bones, for the bones of infants are
three times more solid than those of old men, which contain three times
as much of it. The quantity of phosphate of chalk necessary to the
constitution of animals is in proportion to the temperature of those
animals, and often in the inverse ratio of the weight of their bones, for
vegetables, although they have no bones, require phosphate of chalk. This
is because this salt is the natural stimulant of living membranes, and the
bony tissue is only a depot of phosphate of chalk, analogous to the adipose
tissue, the fat of which is absorbed when the alimentation coming from the
exterior becomes insufficient. Now, as we know all the parts constituting
the berry of wheat, it will be easy to explain the phenomena of
panification, and to conclude from the present moment that it is not
indifferent to reject from the bread this embryous membrane where the
agents of digestion are found, viz., the phosphoric bodies and the
phosphate of chalk.

* * * * *

THE ORIGIN OF NEW PROCESS MILLING.

The following article was written by Albert Hoppin, editor of the
_Northwestern Miller_, at the request of Special Agent Chas. W. Johnson,
and forms a part of his report to the census bureau on the manufacturing
industries of Minneapolis.

"The development of the milling industry in this city has been so
intimately connected with the growth and prosperity of the city itself,
that the steps by which the art of milling has reached its present high
state of perfection are worthy of note, especially as Minneapolis may
rightly claim the honor of having brought the improvements, which have
within the last decade so thoroughly revolutionized the art of making
flour, first into public notice, and of having contributed the largest
share of capital and inventive skill to their full development. So much is
this the case that the cluster of mills around the Falls of St. Anthony is
to-day looked upon as the head-center of the milling industry not only of
this country, but of the world. An exception to this broad statement may
possibly be made in favor of the city of Buda Pest, in Austro-Hungary, from
the leading mills in which the millers in this country have obtained many
valuable ideas. To the credit of American millers and millwrights it must,
however, be said that they have in all cases improved upon the information
they have thus obtained.

"To rightly understand the change that has taken place in milling methods
during the last ten years, it is necessary to compare the old way with the
new, and to observe wherein they differ. From the days of Oliver Evans, the
first American mechanic to make any improvement in milling machinery, until
1870, there was, if we may except some grain cleaning or smut machines,
no very strongly marked advance in milling machinery or in the methods of
manufacturing flour. It is true that the reel covered with finely-woven
silk bolting cloth had taken the place of the muslin or woolen covered hand
sieve, and that the old granite millstones have given place to the French
burr; but these did not affect the essential parts of the _modus operandi_,
although the quality of the product was, no doubt, materially improved. The
processes employed in all the mills in the United States ten years ago were
identical, or very nearly so, with those in use in the Brandywine Mills in
Evans's day. They were very simple, and may be divided into two distinct
operations.

"First. Grinding (literally) the wheat.

"Second. Bolting or separating the flour or interior portion of the berry
from the outer husk, or bran. It may seem to some a rash assertion, but
this primitive way of making flour is still in vogue in over one-half of
the mills of the United States. This does not, however, affect the truth of
the statement that the greater part of the flour now made in this country
is made on an entirely different and vastly-improved system, which has come
to be known to the trade as the new process.

"In looking for a reason for the sudden activity and spirit of progress
which had its culmination in the new process, the character of the
wheat raised in the different sections of the Union must be taken into
consideration. Wheat may be divided into two classes, spring and winter,
the latter generally being more starchy and easily pulverized, and at the
same time having a very tough bran or husk, which does not readily crumble
or cut to pieces in the process of grinding. It was with this wheat that
the mills of the country had chiefly to do, and the defects of the old
system of milling were not then so apparent. With the settlement of
Minnesota, and the development of its capacities as a wheat-growing State,
a new factor in the milling problem was introduced, which for a time bid
fair to ruin every miller who undertook to solve it. The wheat raised in
this State was, from the climatic conditions, a spring wheat, hard in
structure and having a thin, tender, and friable bran. In milling this
wheat, if an attempt was made to grind it as fine as was then customary to
grind winter wheat, the bran was ground almost as fine as the flour, and
passed as readily through the meshes of the bolting reels or sieves,
rendering the flour dark, specky, and altogether unfit to enter the Eastern
markets in competition with flour from the winter wheat sections. On the
other hand, if the grinding was not so fine as to break up the bran,
the interior of the berry being harder to pulverize, was not rendered
sufficiently fine, and there remained after the flour was bolted out a
large percentage of shorts or middlings, which, while containing the
strongest and best flour in the berry, were so full of dirt and impurities
as to render them unfit for any further grinding except for the very lowest
grade of flour, technically known as 'red dog.' The flour produced from
the first grinding was also more or less specky and discolored, and, in
everything but strength, inferior to that made from winter wheat, while the
'yield' was so small, or, in other words, the amount of wheat which it took
to make a barrel of flour was so large, that milling in Minnesota and other
spring wheat sections was anything but profitable.

"The problem which ten years since confronted the millers of this city was
how to obtain from the wheat which they had to grind a white, clear flour,
and to so increase the yield as to leave some margin for profit. The first
step in the solution of this problem was the invention by E. N. La Croix
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.
Ostrander, since deceased, the founder and for a number of years the editor
of the _North-Western Miller_, a trade newspaper. The new ideas were for a
time vigorously combated by the millers, but their worth was so plain that
they were soon adopted, not only in Minneapolis, but by progressive millers
throughout the country. The truth was the 'new process' in its entirety,
which may be summarized in four steps--first, grinding or, more properly,
granulating the berry; second, bolting or separating the 'chop' or meal
into first flour, middlings, and bran; third, purifying the middlings,
fourth, regrinding and rebolting the middlings to produce the higher grade,
or 'patent' flour. This higher grade flour drove the best winter wheat
flours out of the Eastern markets, and placed milling in Minnesota upon a
firm basis. The development of the 'new process' cannot be claimed by any
one man. Hundreds of millers all over the country have contributed to its
advance, but the millers of Minneapolis have always taken the lead.

"Within the past two or three years what may be distinctively called the
'new process' has, in the mills of Minneapolis and some few other leading
mills in the country, been giving place to a new system, or rather, a
refinement of the processes above described. This latest system is known to
the trade as the 'gradual reduction' or high-grinding system, as the 'new
process' is the medium high-grinding system, and the old way is the low or
close grinding system. In using the gradual reduction in making flour the
millstones are abandoned, except for finishing some of the inferior grades
of flour, and the work is done by means of grooved and plain rollers, made
of chilled iron or porcelain. In some cases disks of chilled iron, suitably
furrowed, are used, and in others concave mills, consisting of a cylinder
running against a concave plate. In Minneapolis the chilled iron rolls take
the precedence of all other means.

"The system of gradual reduction is much more complicated than either of
those which preceded it; but the results obtained are a marked advance over
the 'new process.' The percentage of high-grade flour is increased, several
grades of different degrees of excellence being produced, and the yield
is also greater from a given quantity of wheat. The system consists in
reducing the wheat to flour, not at one operation, as in the old system,
nor in two grindings, as in the 'new process,' but in several successive
reductions, four, five, or six, as the case may be. The wheat is first
passed through a pair of corrugated chilled iron rollers, which merely
split it open along the crease of the berry, liberating the dirt which lies
in the crease so that it can be removed by bolting. A very small percentage
of low-grade flour is also made in this reduction. After passing through
what is technically called a 'scalping reel' to remove the dirt and flour,
the broken wheat is passed through a second set of corrugated rollers, by
which it is further broken up, and then passes through a second separating
reel, which removes the flour and middlings. This operation is repeated
successively until the flour portion of the berry is entirely removed from
the bran, the necessary separation being made after each reduction. The
middlings from the several reductions are passed through the purifiers,
and, after being purified, are reduced to flour by successive reductions
on smooth iron or porcelain rollers. In some cases, as stated above, iron
disks and concave mills are substituted for the roller mill, but the
operation is substantially the same. One of the principal objects sought to
be attained by this high-grinding system is to avoid all abrasion of the
bran, another is to take out the dirt in the crease of the berry at the
beginning of the process, and still another to thoroughly free the bran
from flour, so as to obtain as large a yield as possible. Incidental to the
improved methods of milling, as now practiced in this country, is a marked
improvement in the cleaning of the grain and preparing it for flouring. The
earliest grain-cleaning machine was the 'smutter,' the office of which was
to break the smut balls, and scour the outside of the bran to remove any
adhering dust, the scouring machine being too harsh in its action, breaking
the kernels of wheat, and so scratching and weakening the bran that it
broke up readily in the grinding. The scouring process was therefore
lessened, and was followed by brush machines, which brushed the dirt,
loosened up and left by the scourer, from the berry. Other machines for
removing the fuzzy and germ ends of the berry have also been introduced,
and everything possible is done to free the grain from extraneous
impurities before the process of reduction is commenced. In all the minor
details of the mill there has been the same marked change, until the modern
merchant mill of to-day no more resembles that of twenty-five years ago
than does the modern cotton mill the old-fashioned distaff. The change has
extended into the winter wheat sections, and no mill in the United States
can hope to hold its place in the markets unless it is provided with the
many improvements in machinery and processes which have resulted from the
experiments begun in this city only ten years since, and which have
made the name of Minneapolis and the products of her many mills famous
throughout the world. The relative merits of the flour made by the new
process and the old have been warmly discussed, but the general verdict
of the great body of consumers is that the patent or new process flour is
better in every way for bread making purposes, being clearer, whiter, more
evenly granulated, and possessing more strength. Careful chemical analysis
has confirmed this. As between winter and spring wheat flours made by the
new process and gradual reduction systems, it maybe remarked that the
former contain more starch and are whiter in color, while the latter,
having more gluten, excel in strength. In milling all varieties of wheat,
whether winter or spring, the new processes are in every way superior to
the old, and, in aiding their inception and development, the millers of
Minneapolis have conferred a lasting benefit on the country.

"Minneapolis, Minn., December 1, 1880."

THE MILLING STRUCTURES AND MACHINERY.

Mr. Johnson added the following, showing the present status of the milling
industry in Minneapolis:

"The description of the process of the manufacture of flour so well
given above, conveys no idea of the extent and magnitude of the milling
structures, machinery, and buildings employed in the business. Many of the
leading millers and millwrights have personally visited and studied the
best mills in England, France, Hungary, and Germany, and are as familiar
with their theory, methods, and construction as of their own, and no
expense or labor has been spared in introducing the most approved features
of the improvements in the foreign mills. Experimenting is constantly going
on, and the path behind the successful millers is strewn with the wrecks of
failures. A very large proportion of the machinery is imported, though the
American machinists are fast outstripping their European rivals in the
quality and efficiency of the machinery needed for the new mills constantly
going up.

"There are twenty-eight of these mills now constructed and at work,
operating an equivalent of 412 runs of stone, consuming over sixteen
million bushels of wheat, and manufacturing over three million barrels of
flour annually. Their capacities range from 250 to 1,500 barrels of flour
per day. Great as these capacities are, there is now one in process of
construction, the Pillsbury A Mill, which at the beginning of the harvest
of 1881 will have a capacity of 4,000 barrels daily. The Washburn A Mill,
whose capacity is now 1,500 barrels, is being enlarged to make 8,500
barrels a day, and the Crown Roller Mill, owned by Christian Bros. & Co.,
is also being enlarged to produce 3,000 barrels a day. The largest mill in
Europe has a daily capacity of but 2,800 barrels, and no European mill is
fitted with the exquisite perfection of machinery and apparatus to be found
in the mills of this city.

"The buildings are mainly built of blue limestone, found so abundant in the
quarries of this city, range and line work, and rest on the solid ledge.
The earlier built mills are severely plain, but the newer ones are greatly
improved by the taste of the architect, and are imposing and beautiful in
appearance."

DIRECT FOREIGN TRADE.

The flour of Minneapolis, holding so high a rank in the markets of the
world, is always in active demand, especially the best grades, and brings
from $1.00 to $1.60 per barrel more than flour of the best qualities of
southern, eastern, or foreign wheat. During the year nearly a million
barrels were shipped direct to European and other foreign ports, on through
bills of lading, and drawn for by banks here having special foreign
exchange arrangements, at sight, on the day of shipment. This trade
is constantly increasing, and the amount of flour handled by eastern
commission men is decreasing in proportion.

* * * * *

Referring to the foregoing, the following letter from Mr. Geo. T. Smith to
the editor of the _London Miller_ is of interest:

SIR: I find published in the _North-western Miller_ of December 24, 1880,
extracts from an article on the origin of new process milling, prepared by
Albert Hoppin, Esq., editor of the above-named journal, for the use of one
of the statistical divisions of the United States census, which is so at
variance, in at least one important particular, with the facts set forth in
the paper read by me before the British and Irish millers, at their meeting
in May last, that I think I ought to take notice of its statements, more
especially as the _North-Western Miller_ has quite a circulation on this
side of the water.

As stated in the paper read by me above-mentioned, I was engaged in
February, 1871, by Mr. Christian, who was then operating the "big," or
Washburn Mill at Minneapolis, to take charge of the stones in that mill. At
this time Mr. Christian was very much interested in the improvement of the
quality of his flour, which in common with the flour of Minneapolis mills,
without exception, was very poor indeed. For some time previous to this I
had insisted to him most strenuously that the beginning of any improvement
must be found in smooth, true, and well balanced stones, and it was because
he was at last convinced that my ideas were at least worthy of a practical
test I was placed in charge of his mill. Nearly two months were consumed in
truing and smoothing the stone, as all millers in the mill had struck
at once when they became acquainted with the character of the changes I
proposed to make.

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