Glass ^ Book / 5 T3 nu. Concerning Wheat and its Mill Products . BY . . G. L. TELLER. / PRODUCTS OF CERTAIN SMALL. MILLS. With the adoption of roller milling machinery into flour mills the pro-: cesses of flour manufacture and the products themselves have undergone " a radical change from what existed under the old system of mill-stone milling. A more complete separation of the bran from the flour material is made, and the germ or portion of the kernal which produces the sprout, finds its way not into the flour as before, but into the offal. In nearly all mills the flour is divided into two or more qualities and in many mills the offal is divided into two products which are of very different nature and which consequently have different food values. While among flouring mills, each differs from nearly every other in details of construction and arrangement ; they are all essentially the same in that the bran is separated from the interior of the grain, and this interior is reduced to flour by repeated crushing between rollers followed and inter- mingled with numerous separations by suitably arranged bolting machines of various kinds. The details of this process must be left to the miller. The farmer has to do only with the material which he takes to the mill and the products which he takes away or which are sent to him in those sec- tions where wheat is not grown. All of these products in considerable quantities find their way into various parts of this State. They differ in price and have different merits for various purposes. With the above points in mind and also for the purpose of learning something more definite concerning the chemical nature of different parts of 'the wheat grain, which are separated with some distinctness in flour milling, a series of investigations has been in progress during the last three or more years. They have given some results and promise more in the future. Among other things undertaken, three separate test runs of wheat have been made at two different mills. The parts of the mill in use were cleaned as thoroughly as possible of material which it contained from pre- vious work, and a like cleaning was made at the end of each run. The 62 ARKANSAS AGRICULTURAL EXPERIMENT STATION. wheat used and the resulting products were accurately weighed. Small samples of each were taken and submitted to the usual methods of food analysis. Complete ash analyses were made of the wheat and pro- ducts of the third test run. An attempt was also made to separate the products containing nitrogen (crude protein) into different classes based upon an extensive study of this subject recently made by Dr. Osborne at the Connecticut State Experiment Station. The germ of the wheat has in some instances been collected, carefully separated from all foreign matter and submitted to partial analysis. The first milling trial was made in a long process roller mill (7 breaks) grinding about 40 bushels per hour. The other two trials were made in a four break mill, grinding about seven bushels per hour and using the plansifter method of bolting. De- tailed results of these trial runs and results of some of the analyses made are given below. In all of these trials winter wheat grown in Washington County, Ark., was used. In the first trial was a mixture of several small lots brought in during the day by farmers. In the third trial a uniform lot of Fulcaster wheat of fair quality, slightly affected with weavil, was used. That used in the second trial was a red wheat, variety not known. WHEAT MILLING TRIAL No. 1. -MADE JANUARY 2. 1894. Weight uncleaned wheat, 7,000 pounds. Products. Weight Per Cent of Pounds. Uncleaned Wheat. Patent Flour 848 12. 11 Straight Flour 3.964 5 6 - 6 3 Low Grade Flour 250 3.55 Bran i> 6 3° 2 3-37 Tail of Mill (ship stuff) 174 2 -4% 6,872 98.14 1.1 Screenings 7° Loss (dust, etc.) 5° -7 CONCERNING WHEAT AND ITS MILL PRODUCTS. 63 TABLE SHOWING FOOD CONSTITUENTS IN PRODUCTS OF MILLING TRIAL No. 1 Figures show pounds of food material in each 100 pounds of product. Patent Flour. Straight Flour. Low Grade Flour. Ship Stuff. Bran. Whole Wheat. Pure Germ. Water 13-75 ■33 •17 1.05 9.69 75- 01 100.00 I39O •47 .26 i- 2 5 10.37 73-75 100.00 13.22 .90 •74 1.70 12.88 70.56 100.00 12.25 3.I2 3-55 4.80 16.36 5902 100.00 12.85 5.80 6.I4 5.20 I5-56 54 45 IOO.OO 13.90 2.I5 2.I7 2.15 12.31 63-32 IOO.OO 6 80 Ash 4.65 Crude Fiber Fat 14 38 36.OO 36.55 IOO.OO Crude Proteids* Carbohydrates Total Nitrogen 1.70 1.65 05 1.82 1.72 .10 2.26 2.20 .06 2.87 2.68 .19 2-73 2.51 .22 2.l6 I.98 .18 6-34 *Crude proteids in these analyses represent the nitrogen found, multiplied by 5.70, this factor being the result of the average amount of nitrogen found in the proteids of the wheat kernal hy Dr. Osborne as given in the report of the Connecticut Agricultural Experiment Station for 1893, pp. 177-179. For wheat grain this factor gives a far more accurate result than does the factor 6.25, which has heretofore been in general use. WHEAT MILLING TRIAL NO. 2— MADE MARCH 15. 1894. Weight uncleaned wheat, 3,000 pounds. Products. Weight Per Cent of Pounds. Uncleaned Wheat. Patent Flour 529.5 1 7.65 Straight Flour 1,510.5 5°-35 Low Grade Flour 69 5 2.32 Shorts 33° I -io Dust Room Contents 24.5 .82 Bran 723 o 24.10 Screenings 81.0 2.70 Sample Cleaned Wheat 1.5 .05 Loss 27.5 .91 3,000.0 100.00 64 ARKANSAS AGRICULTURAL EXPERIMENT STATION. TABLE SHOWING FOOD CONSTITUENTS IN PRODUCTS OF MILLING TRIAL NO. 2. Figures show pounds of food material in each ioo pounds of product. Patent Flour. Straight Flour. Low Grade. Dust Room. Ship Stuff. Bran. Wheat Cleaned. Water I4.05 .26 •17 •93 8.49 76.10 100.00 I4.O4 •35 .22 1.27 9.80 74-32 100.00 I3.9O •78 •54 1.80 13- 79 69.19 100.00 I3.04 2.8l 6.06 3 15 12.65 62.29 100.00 13 5° I 21 •98 2.5O I4.82 66.99 IOO OO 12-55 5-8 5 6.51 4.80 16.30 53-99 100.00 13 70 I.85 2.03 I.85 II.40 69.17 lOO.OO Ash Crude Fiber Fat Crude Proteids* Total Nitrogen 1.49 1.72 2.42 2.22 2.60 2.86 2.00 Weight uncleaned wheat, Products. * Crude proteids equal nitrogen multiplied by 5.70. See under Milling Trial No. 1. WHEAT MILLING TRIAL No. 3.— MADE NOVEMBER 30, 1894. ,000 pounds. Weight Pounds. Patent Flour 774 Straight Flour 1,260 Low Grade Flour 116 Dust Room Contents 35 Ship Stuff 34 Bran 714 Screenings. Tailings Loss 2,933 55 Per Cent of Uncleaned Wheat. 25.80 42 00 3-87 1. 17 23.80 97-77 1.83 ■33 .07 TABLE SHOWING FOOD CONSTITUENTS IN PRODUCTS OF MILLING TRIAL No. 3. Figures show pounds of food material in each 100 pounds of products. Patent Flour. Straight Flour. Low Grade. Dust Room. Water I4.OO •31 .18 .85 8.78 75-88 IOO 00 13.98 .40 .26 1.00 9.98 74-88 lOO.OO 13.90 .70 •47 i-75 12.14 71.04 100.00 I3-05 2 50 4.4I 3-65 12-37 64.O2 lOO.OO Ash Crude Fiber Fat Crude Proteids* Total Nitrogen i-54 i-75 2.13 2.17 Ship Stuff. Bran. 12.50 I2.6o 3.08 5- 2 5 3-07 6.5I 4-75 5.OO 15^5 I5-56 60.75 55- 10 100.00 100.00 2.78 2-73 13.80 1.62 2.50 1.90 II. 17 69.11 100.00 1.96 *Crude Proteids represent the nitrogen multiplied by 5.70 as indicated in note under results of Milling Trial No. 1. CONCERNING WHEAT AND ITS MILL PRODUCTS. 65 The dust room contents mentioned above consists largely of fhe outer portion of the bran mixed with a little material which would otherwise have made flour. A sample of this material was sifted to remove the flour particles and the residue, consisting of the material which millers call 4i bees wings" was analyzed. The results are given below in connection with the analysis of screenings from milling No. 3. TABLE SHOWING COMPOSITION OF SCREENINGS AND SIFTED DUST. Water. Ash. Crude Fiber. Fat. Crude Pro- teids. Carbohy- drates. Sifted Dust 6.25 Screenings 12.70 2.25 2-57 19.77 3-55 .78 2.5O S-i3 12.03 65.82 66.65 The analysis shows this wheat screenings to be a valuable article of food for stock and such is the usual case with this offal. A short discus- sion of the food value of ship stuff and bran is given in Bulletin No. 30 of this station, page 158, and is in accordance with what the above analyses teach. As that bulletin is probably in the hands of most of the readers of this one, the discussion need not be repeated here. In the smaller mills these articles are usually run together and sold simply as bran, but they are kept separate in larger mills, and that which is sold as ship stuff will usu- ally cost about $i. 00 per ton more than the bran. The relative compo- sition of these two articles differs in the output of different mills, but in general the ship stuff has an increased food value corresponding in a meas- ure with the increase in price. CLASSIFICATION OF FLOURS. Since the details of flour manufacture differ so greatly in different mills it is apparent that the products from all mills will not be of uniform quality. So, too, the wheat used, its condition when milled, the condi- tion of the mill and other things tend to vary the quality of the output from the same mill at different times. These variations are often recog- nized by purchasers of the flour, and on the other hand, flour is probably often blamed for being poor when the difficulty lies wholly or in part with the user of it, as when it is not adapted to the special details of bread baking habitually practiced by that person. Nearly all mills sell their flour under special brands or trade names. Often these are registered under government laws and can be used by other millers only at their peril. Each miller will have as many of these 66 ARKANSAS AGRICULTURAL EXPERIMENT STATION. trade names as he has qualities of flour. If the flour sold under the same name were always of uniform quality, purchasers might be guided mate- rially by them, but for reasons indicated above, these qualities are not always uniform. There is little doubt, however, that the mill brand fur- nishes the most reliable guide which purchasers of small quantities of flour have for judging of the quality of the article which they wish to purchase. There are means at the disposal of large consumers of flour which enable them to judge quite accurately of the quality of the article they are buying. Such means are, comparison of color, capacity to take up water, accurately conducted baking tests which may be readily applied to small quantities of many samples of flour, and other means, the details of which cannot be given here. These methods are resorted to by professional bakers and others, the amounts of whose purchase justify the expenditure of the time and labor and the purchase of the necessary apparatus. In large market centers, such as St. Louis, Chicago and Philadelphia, the flour which is bought or sold by local dealers is often submitted before the transfer to inspection by authorized flour inspectors. These report upon the average weight and condition of the separate packages and their contents, and the terms of the sale are arranged accordingly. A quite thoroughly organized inspection is carried on in St. Louis under the direction of the Merchants' Exchange. Here, when inspected, the packages of flour are stamped with the brand of the flour inspector, which mark indicates the date of inspection, the weight of the package, the condition of the contents as to soundness or unsoundness, and may in- dicate its quality or grade. Quality or grade are indicated by names adopted by the Board of Flour Inspectors in much the same way as trade names are adopted by a mill owner. The names of the grades of the St. Louis Merchants' Exchange Board of Flour Inspectors are : Patent, Extra Fancy, Fancy, Choice, Family. The first named indicates the whitest and highest quality, the last indicates the darkest and lowest grade of flour. The other names indicate intermediate grades corresponding to the posi- tions which the names occupy in the above list. As a guide for the use of the various deputy flour inspectors the Board of Flour Inspectors prepares a series of standard grades to be used for comparing with the flour which is being inspected. Many of the millers of St. Louis and vicinity also obtain samples of these standards and gauge the qualities which they produce by them. To provide against changes which flour undergoes with age, fresh standards are prepared at intervals of two or three months. CONCERNING WHEAT AND ITS MILL PRODUCTS. 67 Market quotations from St. Louis, Memphis and Little Rock state prices for all or part of the above grades of flour and use those terms for designating the different qualities of flour upon the market. Other cities, like Philadelphia, Baltimore and Boston, use different names for their standard grades, and some cities in which inspection is carried on use none whatever. Flour inspection in the various cities is for the most part under the control of merchants who have organized and established the system for their mutual protection. There is every reason for believing that it is a most effectual means of protecting both buyer and seller. More than a suggestion as to the value of an efficient system of flour inspection, where- by the actual quality of any flour in the market may be known to the con- sumer, or purchaser of small quantities, cannot be given here. There are reasons for believing that such a system would be of material benefit to all who have anything whatever to do with this article. COMPOSITION OF FLOURS. An examination of preceding tables of analyses show that the highest proportion of carbohydrates is found in the whiter flours. In a perfectly ripened, unsprouted wheat these carbohydrates consist almost entirely of starch. The low grade flours contain much less carbohydrates than the patent flours. The analyses also show an increase of fat, ash and fiber in the lower grades of flour. A very marked variation in the amount of crude proteids also occurs. Further examinations, the results of which are not given in the preceding tables, show the different groups of proteids, which together make the total proteids to differ very markedly in their relative proportions in these different grades. The proteids which are considered of most importance in wheat flours are those which constitute what is known as gluten. Gluten is an elastic semitransparent mass of material which remains when flour is carefully washed with water in such a way as to remove the large quantities of starch and other matters which always occur with it. If a few spoonfuls of flour are mixed with water to a moderately stiff dough and allowed to stand for an hour in a saucer or other convenient dish the threads of gluten may be readily seen by pulling the mass apart with the fingers. If the mass of dough be placed in a strong cotton or linen cloth and worked between the thumb and fingers in a quantity of water until a fresh supply of water does not become milky from separated starch after a few minutes working, nearly pure gluten will remain in the cloth and its nature can then be readily seen. 68 ARKANSAS AGRICULTURAL EXPERIMENT STATION. It is this gluten which gives wheat flour its peculiar value for bread making purposes. The carbonic acid gas which is formed by the growth of yeast in a mass of bread dough, or which is set free from baking powder when it is wet with water, or from baking soda when it is wet with sour milk, accumulates itself in numerous small pockets which it forms in the dough. These pockets are formed because of the presence of this tenacious gluten which is so elastic as to permit the gas to force it aside without breaking it and yet so compact as to prevent the escape of the gas. The walls of the pockets formed retain their places when the bread or cake is baked, giving a light porous loaf very different from that of bread made from corn flour. Corn contains no gluten. The gluten of different flours differs not only in amount but in quality. Bakers like a flour containing much of a very strong gluten. Such flours will take large quantities of water and make more bread to a given weight of flour. Consumers of baker's bread and those who bake their own flours do not want water from this source. They want bread. However, most all who use light bread wish a light porous loaf, and to obtain this a flour must be used which contains a sufficient amount of a good quality of gluten. They also want a bread which will retain moisture well, which will be light in color and which will be agreeable* to the taste. These qualities they cannot get by the use of a very low grade of flour. In many instances they probably cannot get all of them by the use of a very high grade, because such flours are made from the more starchy portion of the grain and are deficient in gluten. Flour from hard spring wheat contains much gluten of a high quality -and is much sought after by some bakers, who use it either alone or to mix with other flours. There does not seem to be reasons for believing that flours from soft winter wheat produced in this section of country are so •deficient in gluten as to make them in any way inferior for general use. This is especially true since much of the bread consumed in this State is •used in the form of warm biscuit, for the making of which flours from soft wheat are even more suitable than from hard wheat. Lower grades of flour can also be used for the making of warm bread than for the making of the so-called light bread. The most suitable use for human food to which very low grades of flour can be put is to the making of griddle cakes for which purpose they seem even superior to the better qualities of flour. It is a common opinion of many that the highest priced article of any kind will prove most economical in the long run. This is not necessarily true of wheat flours. High priced flours are preferable to some because of CONCERNING WHEAT AND ITS MILL PRODUCTS. 69 their very white color. The medium grades of flour will contain more gluten and yet do not partake in a very large degree of those objectionable qualities found in a very low grade. Different individuals differ in their tastes and some will prefer the flavor of a lower grade to that of the highest. There is unquestionably a difference in the amount of waste which will occur from breads made of different qualities of flour, and this difference will vary for the same flour according to the tastes of consumers of the bread. In general the lower grades of flour from the same wheat will contain the highest proportion of gluten. This increase of gluten is, however, less than the increase of crude proteids. There has been a common prac- tice of pronouncing food containing a large proportion of proteids to be superior foods ; that is, foods supplying a greater amount of nutriment. In the case at least of different flours from the same wheat there are other matters which come in direct opposition to this. As bearing directly on this point the following extract is quoted from a valuable paper on the chemistry of wheat and flour published by Lawes & Gilbert, of England, in 1857: "It is also well known that the poorer classes almost invariably prefer the whiter bread ; and among some of them who work the hardest, and who consequently would soonest appreciate a difference in nutritive quality (navvies, for example), it is distinctly stated, that their preference for the whiter bread is founded on the fact, that the browner passes through them too rapidly; consequently, before their systems have extracted from it as much nutritious matter as it ought to yield them." The authors of this sentence attribute the facts stated to the mechani- cal action of the hard, branny particles upon the intestines. In those days milling was entirely done by the use of millstones, and a much larger pro- portion of bran found its way into the flours than occurs with the roller process now in use. An examination of the tables of analyses does not show a large proportion of crude fiber even in the lowest grades of flour and yet there are some reasons for believing that this laxative influence possessed by low grade flours in those days still occurs. The proteids not gluten are much more abundant in the bran than in the flours, and the laxa- tive effect of bran-mash fed to horses and other animals which consume such coarse fodders as hay, can hardly be attributed to the hard, branny particles, because bran contains not more than one-fifth as much crude fiber as the average hay, and that which it does contain is not less easily softened by moistening than that which is contained in the hay. It would seem, there- fore, that the laxative effect of bran and low grade flours is due rather to the kind of proteids which they contain than to the mechanical action of their branny particles. 70 ARKANSAS AGRICULTURAL EXPERIMENT STATION. This laxative action of bran and low grade flours may be made to serve a useful purpose as a food for some, and finely ground whole wheat meal, or graham flour, may be especially useful for that purpose and for giving a change of food as well as for supplying a larger proportion of bone forming material, which it contains as ash. Where bread forms a very large proportion of the food this special value of the ash constituents, especially for growing children, may be great. Where considerable quan- tities of other foods, such as vegetables, milk and meat, are consumed, the bone material will be supplied in sufficient quantities even when the very whitest qualities of flour are used. Among other foods, peas, beans and oatmeal are especially rich in bone forming material. THE FERTILIZER ELEMENTS CONTAINED IN WHEAT. The ash of wheat is made up chiefly of the phosphates of potash, magnesia and lime. The results of a complete series of analyses of the ash of the products obtained in the third milling trial is given in Part 2 of this Bulletin, and the percentage of all the ash ingredients of each ash is there shown. For the purpose of illustrating here some important points, the absolute weight, in pounds, of the phosphoric acid, potash, magnesia and lime computed for the entire weight obtained of each of the mill products, and of a corresponding amount of the cleaned wheat, are given in the table below. The weight of total nitrogen occurring in each is also given. TABLE SHOWING WEIGHT OF CHIEF ASH CONSTITUENTS OF WHEAT AND ITS PRODUCTS. Patent Flour, lbs. 774- 2-399 I-I53 •924 .105 •139 II.92 Phosphoric Acid Potash Magnesia Straight Flour. Low Grade. Dust Room. Ship Stuff. Bran. Wheat. lbs. lbs. lbs. lbs. lbs. lbs. I26o. Il6. 35- 34- 714. 2933- 5.040 .812 •875 I.O44 37342 47-5H 2.486 I.830 .322 .287 ■431 .262 .076 ■037 •437 .270 •i>3 .031 ■570 •293 .138 .029 19.720 IO.527 5-512 ■933 24 715 14 112 6.286 1-473 2205 2.47 .76 •945 19.50 57-48 It will be seen from the above that of the valuable fertilizing elements which occur in wheat there are found in those mill products which are used CONCERNING WHEAT AND ITS MILL PRODUCTS. 71 for stock food, about seven-eighths of the entire phosphoric acid, eleven- fourteenths of the potash and three-eighths of the total, nitrogon. The total value of these three fertilizing elements, based upon prices at which they can be obtained in market centers of this State, is $7.50 for the 50 bushels of wheat. Almost one-half of this value of fertilizing elements is found in the bran and other offal. As has been pointed out in previous bulletins of this division of the Experiment Station, little of these fertilizing elements are retained by the animal to which the food is fed. If the bran be recov- ered from the mill to which the wheat is taken, fed to stock and the result- ing manure carefully saved, nearly one-half of the soil fertility which would otherwise be lost in the selling of the wheat will be preserved and the live- stock will have the benefit of a most excellent concentrated food. Readers are here reminded, however, that this is only one argument concerning a method of practice, a discussion of which does not come under the scope of this publication. It may be further pointed out in this connection that Lawes and Gilbert in England, have found as partial results of an extensive experiment on wheat, grown under different methods of manuring and for many years in succession on the same soil, that the average amount of straw which will produce 50 bushels of wheat is about 5,000 pounds. They found further that this straw will contain an average of 7.6 pounds of phosphoric acid, 21.5 pounds of nitrogen, and 44.8 pounds of potash. These, valued at the same prices as in the preceding paragraph, would show the fertilizing elements in the straw to be worth $4.53, or about three-fifths of the value of tbe fertilizing elements in the 50 bushels of wheat which the straw would produce. The straw itself contains fertilizing elements greater in value than are those contained in the flour of the wheat. One of the greatest needs of many of the soils of this State is more vegetable matter, and straw applied to the soil has a value beyond that due to the presence of the most important fertilizing elements which it contains. In those sections where wheat is produced the straw should be preserved and made to assist in maintaining the fertility of the soil. The finding of zinc in the ash of this wheat may be mentioned as a point of special interest. The amount found would equal about 1 pound of pure zinc to each 500 bushels of wheat. So far as it has been possible to learn, this small amount of zinc has no special influence upon the growth of the plant nor is it in any way injurious to animals or human beings eating the grain. It is found most abundantly in the ash of the outer portions of the grain and is present in the flour ash in much less quantities than in the 72 ARKANSAS AGRICULTURAL EXPERIMENT STATION. ash of the bran. In the ripened wheat it seems to have been transferred almost completely from the straw to the grain. Zinc was also found in oats, clover hay and corn cut before tasseling. All of these were produced upon soil in the vicinity of that producing the wheat which was used in the mill- ing trial. An examination of the first 6 inches of this soil showed it to contain about i pound of zinc to each 1,000 pounds of earth. Zinc has been previously found in the ash of many plants and of some animals in Europe. Its presence in considerable quantities in drinking water has produced no noticeable injury to those using it for many years. LOSS DURING THE SPROUTING OF WHEAT. While everybody recognizes that wheat is injured by sprouting, as when in shock, the amount of loss which occurs is not generally understood. In an experiment for a purpose pointed out in Part 2 of this Bulletin, equal weights of the same wheat were sprouted, under uniform and most favor- able conditions, for different lengths of time varying by intervals of twenty- four hours each. Each sample at the close of its sprouting period was carefully air dried and later the absolute amounts of dry matter in each and in the original wheat were determined. This was necessary to give a uniform basis of computation, as otherwise accidental variations in the amount of moisture may have given misleading results. In the following table is given the amount of wheat which would remain from 100 bushels of the original wheat after it had sprouted for the number of hours shown in the first column of the table and had then been dried till it contained the same amount of moisture which was present before it was wetted for the sprouting. The number of bushels lost from each 100 bushels of the original wheat is also indicated. TABLE SHOWING LOSS OF WEIGHT UNDERGONE BY WHEAT SPROUTING FOR DIFFERENT LENGTHS OF TIME. „,. „ ., Part? Remaining of Parts Lost of Time Sprouted. Each 1QQ Parts> Each 1QQ p arts> 24 hours 98 5 1.5 48 hours 97.5 2.5 72 hours 94.1 5-9 99 hours 93-3 6.7 120 hours 89.9 10. 1 144 hours 88.2 11.8 At the end of the sixth sprouting period two of the more advanced grains were beginning to burst their first leaf and a large number of other CONCERNING WHEAT AND ITS MILL PRODUCTS. 73 grains were not far behind in the sprouting stage. The most advanced kernals were, however, not beyond the stage where wheat shocks begin to turn green from the sprouting grain. It was endeavored to carry on this experiment under such conditions that the entire amount of wheat was given the best possible conditions for its sprouting. It is probable that the sprouting of the entire mass of wheat in shock does not generally occur, but it is apparent from the foregoing results that there is a decided loss in the weight of the harvest when wheat is allowed to sprout for a very short time only, and the amount of loss for a given length of time will be dependent upon the amount of wheat affected. Aside from the loss in weight which occurs in the sprouting of wheat, marked chemical changes are brought about which decrease greatly the value of the article for bread baking purposes, and probably also as a food for stock. The importance of protecting the wheat by proper stacking or storing in barns as soon as possible after it is ripe and dry is great. The expense of stacking will often be small as compared with losses which may occur by attempting to wait till a machine can be procured for the purpose of threshing direct from the shock. It is possible that the lack of profit to the farmer is often brought about through the many small losses of this character which might be pre- vented. Successful manufacturers, merchants and others make it a point to look after the apparently unimportant details of their business with the greatest of care and to insure against loss, whether by fire, wind or rain, is almost universally acknowledged to be a sound business principle. G. L. Teller, Station Chemist. Part 2 of this Bulletin contains a record of certain investigations con- cerning wheat and its mill products, the results of which have either been briefly stated for the use of the farmer in Part i, or are not yet sufficiently developed to be adapted to their needs. These investigations are, how- ever, of more or less importance to experiment station workers and others engaged in scientific studies, and that they may be accessible to such they are grouped together and published in a limited edition of a few hundred copies only. Parties desiring a copy of the same may obtain it by writing for Bulletin No. 42, Part 2. Part 2 of this Bulletin treats of the following subjects : A Complete Ash Analysis of Wheat and its Mill Products. Alumina a Constituent of the Ash of Certain Wheat. Zinc a Constituent of the Ash of Some Arkansas Farm Plants. Studies Concerning the Proteids of Wheat and a Method for their Quantitative Separation. COMPOSITION OF THE ASH OF A WHEAT AND ITS MILL, PRODUCTS. The following series* of ash analyses was made for the purpose of obtaining some further information concerning the distribution of various ash ingredients in the wheat grain and in the different products of modern flouring mills. The samples examined are those of the milling trial No. 3, of which detailed results are given in Part i of this bulletin. The figures given in the table indicate in per cent of total ash, the amount of each constituent named. Patent Flour. Straight Flour. Low Grade. Dust Room. Ship Stuff. Bran. Wheat. 2-33 .41 •47 38.50 0.00 5-59 4-39 48.05 .16 1.28 •15 .26 36.31 O.OO 5.65 6.44 49-32 •52 .04 99-97 •5° .12 • 2 5 32.27 0.00 4-5i 9-33 .00 1-34 .04 •30 30.85 0.00 3-53 12.90 49-94 •58 .49 .18 •37 28.03 O.OO 2.8o 13-27 54.62 .00 •97 .07 .27 28.19 0.00 2.50 14.76 52.81 .10 .01 .27 99-95 1,04 .1 1 .27 29.70 O.OO ^?.IO Magnesia I3-23 52.14 .22 Phosphoric acid •OI Zinc oxid -46 •36 .24 100.08 Sum 99.90 99.94 IOO.I2 IOO.06 Per cent total ash in each •3i .40 .70 2.50 3.08 5- 2 5 1.62 The ashes for these analyses were prepared in a Fletcher's muffle furnace No. 5, heated by an ordinary Fletcher's gas cooking burner. The *The results of a somewhat similar series of ash analyses by Dempwolf are given in Annalen der Chemie und Pharmacie, Bd. 149, pp. 343, 350. 1869. 76 ARKANSAS AGRICULTURAL EXPERIMENT STATION. platinum dishes in which the material was burned are capable of holding about fifty grams of the pulverized material each. The muffle is just large enough for two of these dishes. As the material in the dishes decreased sufficiently in bulk 25 grams of fresh material was added and this was continued till enough had been taken to produce a sufficient amount of ash. The burning was then continued till the ash was of a very light gray color. Care was taken in each instance that the temperature of the muffle in its hottest place should not rise above a gentle redness. The dishes were protected from the bottom of the muffle by a thick sheet of asbestos cloth. The ash thus produced did not fuse and was perfectly loose and free. The small amount of unburned carbon was determined and deducted from the crude ash to give the pure ash upon which all computations are based. No carbonic acid was found. The analyses of ash were all made by me per- sonally with as much care as could be commanded. It has been suggested that the absence of sodium and chlorine in these ashes may be due to their having been volatilized during the burning. This error is possible. However, it could not well be prevented. Attempts were made to extract the charred mass with dilute acetic acid as soon as all volatile matter was driven off but the char was a porous, very hard mass, which could be pulverized only with great difficulty and which could not be well extracted otherwise, so that the probabilities of error by this method seemed much greater than by direct burning. The method is, too, essen- tially that used by Lawes & Gilbert in the preparing of the considerable number of wheat ashes which they have had analyzed, except that they were not required to add the unburned material in parts. Among the variations in composition in the ash from different parts of the wheat grain the most noticeable are the very marked increase in the proportion of potash and lime toward the interior of the grain and the still greater decrease in the proportion of magnesia in the same direction, that is, from the bran to the whitest flour. The presence of zinc will be dis- cussed later. It was present only in very minute quantities in the ash of the flour. The amounts could not be determined in the patent and low grade flours for the want of more material. The variation in the amount of sulphuric anhydrid present was to be expected. It indicates nothing special. Any sulphates present may easily have been reduced and the sulphur volatilized in the burning of the ash. Sulphur is alwa)s present as one of the essential elements of the proteids, and would, under suitable conditions, have been converted into sulphates during the burning. The presence or absence of sulphur in the ash is CONCERNING WHEAT AND ITS MILL PRODUCTS. 77 probably largely dependent upon the relative proportion of the strong bases and the phosphoric acid in the material burned. A determination of the total sulphur in each material was made by fusing 2 grams of the substance with a sufficient amount of nitrate of potash and potassium hydrate in which the absence of sulphur in weighable quantities had been verified. PER CENT OF SULPHUR IN WHEAT AND ITS MILL PRODUCTS. Patent Flour. Straight Flour. Low Grade Flour. Dust Room Contents. Ship Stuff. Bran. Wheat. .09 .IO .16 •15 •17 .21 •13 ALUMINA IN THE ASH OF WHEAT. The finding of alumina in the ash of plants has been often mentioned but it has been attributed to possible clay or dust adhering to the surface of the material from which the ash was obtained. Wanklyn* and Cooper report alumina to be a usual constituent of wheat flours. They attribute the presence of a pirt of it to the wearing down of the millstones. This could not have been a source of the material in these mill products, as the wheat was crushed entirely by iron rollers and an examination of the amounts of alumina found in the mill products and in the whole grain in- dicate that it is no more foreign to the true ash than any of the other con- stituents named. To bring further proof on this point, 100 grams of the unground wheat was carefully washed with distilled water, and after drying, was burned without being pulverized. The same amounts of both alumina and zinc were found as in the wheat which had not been washed. It seems a little remarkable that the zinc should have accumulated to the greatest extent in the ash of the bran while the alumina and silica should have reached their largest proportion in the ash of the finer flours. Alumina is found to be of frequent occurrence in the mineral waters of this State. t To ascertain as to whether alumina will be present in the ash of wheat grown on a very sandy soil, a sample of wheat was obtained through the kindness of Dr. Palmer, of Grayling, Mich., where it had grown upon the Jack Pine Plains. The wheat was thoroughly washed, pulverized and burned and treated for alumina as in the other instances, but none was found. * Bread analysis, p. 24. {Arkansas Geological Survey. Report for 1896, Vol. 1. 78 ARKANSAS AGRICULTURAL EXPERIMENT STATION. In all these analyses the phosphates of iron and alumina were sepa- rated from the remainder of the ash by the use of acetate of sodium or ammonium, acetic acid and the temperature of boiling water. To remove other phosphates which were carried down from the concentrated solutions they were dissolved in acid and reprecipitated. These phosphates were then weighed in a platinum crucible in which the filter on which they were collected had been burned. They were then dissolved in the smallest possible quantity of hydrochloric acid, and the solution made to ioo c. c. 10 c. c. of this solution was placed in a Nesslerising cylinder containing one cubic centimeter of strong nitric acid. Two cubic centimeters of ammonium sulphocyanid of the usual reagent strength was added and the contents of the cylinder made to the 50 or 100 c. c. mark. Other Ness- lerising tubes were filled in like manner, except that in place of the solu- tion to be analyzed different quantities of a solution of ferric chloride con- taining .0001 grams of iron to each cubic centimeter were used. By carefully comparing tints in the different cylinders, the number of one- tenth milligrams of iron in the 10 c. c. of solution compared may be readily ascertained.! This has been found to be a very ready and satisfac- tory method of estimating the small quantities of iron contained in these ashes. The alumina was computed from the aluminum phosphate found by difference. The presence of the alumina was also verified by the usual qualitative methods. OCCURRENCE OF ZINC IN THE ASH OF SOME PLANTS. Certain ash elements are found in all plants and are essential to their development. Other elements which are only occasionally present in soils may be taken up by plants growing on them though they may have no effect upon the growth of the plant. Among these are manganese, copper, zinc and even arsenic. Their presence is a matter of interest and their general distribution seems a question worthy of some attention. Animals and human beings using the plants for food may accumulate the metals in their system and the discovery of their presence by those unacquainted with their frequent occurrence might lead to various complications, such as the apparent proof of supposed criminal poisoning when none had really occurred. The finding of zinc in this wheat was quite unexpected. Though the . section of country in which the wheat was grown shows to the most casual JBread analysis. Wanklyn and Cooper, p. 34. CONCERNING WHEAT AND ITS MILL PRODUCTS. 79 observer, characteristics in common with some regions in Southern Mis- souri, where zinc is obtained in abundance, zinc has never been found in paying quantities in this vicinity. The history of the wheat was sought out and a sample of the first 6 inches of soil in the field in which it was grown was obtained. This surface soil is, when dry, of a light mouse color. In quality it is a clay loam containing when taken from the field, a few gravel stones of considerable size. The deep subsoil is heavy clay of yellow or reddish yellow color. The sifted air dry soil yielded to hydrochloric acid .42 per cent of zinc oxide, equal to 7.8 pounds of metallic zinc per ton. Two samples of wheat grown on opposite sides of this first field were taken soon after they were cut in the summer of 1895. The ash of one was found to contain .30 per cent of zinc oxide and of the other .12 per cent, the latter being only one-half of that found in the ash of the wheat milled. Among the mill products of this latter wheat it was found most abundantly in the contents of the dust room which is made up largely of the outermost coat of the bran. The next greatest quantity was found in the ash of the ship stuff and the least in the ash of the flour. No zinc oxide whatever was found in the ash of 100 grams of the straw from one of the above wheats and none in the ash from 50 grams of the other straw. Red clover growing on the field which produced the wheat in 1894 showed .004 g. zinc oxide in the 7.449 g. of a very pure ash from 115 g. of the entire plant. This corresponds to .06 per cent of zinc oxide in the ash of the clover. Corn fodder cut from an adjacent field before tasseling and when about 3 feet high, showed .0065 grams of zinc oxide in the 8.670 g. of ash from 90 g. of the air dry fodder. This corresponds to .07 per cent of zinc oxide in the ash of the corn fodder. This ash was, however, a little dark and contained a little carbon, the amount of which was not determined. A sample of ripe oats grown on a field not far away contained .12 per cent of zinc oxide in the 2.840 g. of a very light gray ash from 100 g. of the grain. Here again no zinc was found in the straw. It would seem, there- fore, that as the plant ripens the zinc is transferred to the outer portion of the grain produced. Frequent mention has been made of the presence of zinc in a small plant ( Viola calminaria) which grows in the vicinity of zinc mines in Europe. It is written 1 that the growth of this plant has been taken as an indication of the presence of zinc and that when made to grow upon a soil which contains no zinc it undergoes a change of form and color. Lechar- tier and Bellamy, 2 of France, investigated the presence of zinc in the ash of 1. Encyclopedic Chetnique, t. x., p. 97, and Annates Agronontiques, t. x., p. 478. 2. Comtes Rendus, t. x. LXXXIV. No. 15, p. 687. 80 ARKANSAS AGRICULTURAL EXPERIMENT STATION. certain plants, animals, and their products. They found it in notable quantities in the livers of two men of different occupations and dying of different diseases. They also found it in veal, beef, the eggs of poultry and in the grain of wheat, barley, maize, harcot beans and winter vetch. They also examined for it the sugar beet, the stems of corn and green clover and were not satisfied of the presence of zinc in these. In their determin- ation of zinc, as well as in those made here, care was taken that the zinc could not come from any other source than the material examined. The presence of zinc in considerable quantities in many plants has been verified by Sachs and by still others. Ant. Beaumann 3 has grown various plants in solutions containing salts of zinc and all mineral matters necessary for the development of the plant. He found that when the zinc present did not exceed one milligram per liter of water, the plants grew very well and that the zinc was absolutely inoffensive. When the amount of zinc was increased to about five milli- grams per liter it became a poison and the plants soon perished. When solutions of either sulphate or carbonate of zinc were so strong as to de- stroy plants having their roots in them they had no evil effect when added to a soil upon which similar plants were growing. This is attributed to the precipitation of the zinc from solution by the presence of certain of the soil ingredients, thus rendering it much less capable of entering the roots of the plant. This author attributes the injurious action of the zinc to its attacking the chlorophyll. He also cites the experiments of M. Raulin, in which it was found that the presence of a small quantity of zinc had a decided beneficial influence upon the growth of black mould {asper- gillus niger). This plant contains no chlorophyll. So far as known the presence of zinc in plants exerts no influence upon animals consuming them, and it is stated upon the authority of E. Mylins 4 that water of a certain public well of Europe which contains .007 grams of zinc oxide per liter has been used for drinking purposes for more than a century without any perceptible injury to man or beast. 3. Die Landszuirtschaftichen Versuchsstationen, XXX. volume ler. fascicule. Abstract in Annates Agronomiques, t. x., p. 478. 4. Chemical News, vol. XLII, p. 49. CONCERNING WHEAT AND ITS MILL PRODUCTS. 81 THE QUANTITATIVE SEPARATION OF WHEAT PROTEIDS. Extensive investigations have been made and much has been written* by various experimenters concerning the presence of amides in plants, especially young and immature ones, and concerning the formation of amides during the sprouting of seeds and of their later transformation into proteids in the growing seedling. Extensive investigations have also been made concerning the character and composition of proteids in plants, especially in mature grains and seeds, but so far as known no efforts have been made to study the relative formation and decomposition of such pro- teids which normally take place in seeds during their development and germination, nor does any extensive investigation seem to have been made concerning the relative proportion of different proteids in like grains or seeds of different characteristics such as often occur in plants of the same species when grown under different conditions as to soil, climate, seasons, etc. While such knowledge concerning the proteids of any agricultural plant gives promise of being of ultimate value to the science of agriculture it seems likely that a knowledge of the kind indicated concerning the proteids of wheat will be of special value because of the probable close association of these variations with the milling qualities of the grain and the consequent value for baking purposes of the flours produced. It seems probable that the relative proportions of the different proteids may bear close relations to well recognized characters of the grains. The nature and amount of gluten contained in wheat flour frequently gives important information concerning the quality of that flour. It also gives some information concerning the value of a wheat for flouring pur- poses and more or less use has been made of knowledge concerning it in selecting varieties of wheat for growing in special localities. The mechan- ical methods of separating gluten which are now extensively used are acknowledged to be very imperfect and unsatisfactory and it seems that a a short but definite chemical method of ascertaining the amount of gluten in wheat or flour will be of great value to the chemist in his examination of those articles. The important work of Osborne and Voorhees in the Connecticut Ex- periment Station has given definite information concerning the kinds of * For review and bibliography concerning studies on Asparagin up to 1879 see paper by M. Campus Annales Agronomiques, t. V. p., 578. 82 ARKANSAS AGRICULTURAL EXPERIMENT STATION. proteids in sound mature wheat. Accepting for the most part their classifi- cation of these proteids an effort has been made to perfect a ready method of quantitative separation for the purpose of obtaining such information as has been indicated, including a method for the determination of gluten. The matter did not prove as simple as it at first seemed, and it is hardly possible in this report of progress to go beyond a description of the pro- posed method of analysis, giving in connection therewith the more impor- tant analytical data which led to the selection of the method of analysis and, by way of illustration, the results of a few proximate analyses of the proteids of a few different wheats and flours. In as much as the following work is based almost entirely upon the characteristics of wheat proteids described by Osborne and Voorhees, and as a record of their work may not be readily accessible to all readers, the names and descriptions of these proteids as given by them in the Report of the Connecticut Agricultural Experiment Station for 1893, (p. 175, 185) are here repeated. With exceptions hereafter noted the presence in wheat and flour of proteids having the characteristics described by them have been frequently verified in the laboratory here, though no effort has been made to show their identity in composition. "I. Gliadin is the proteid which is readily dissolved from wheat flour and from gluten by hot dilute alcohol. * * * In absolute alcohol gliadin is entirely insoluble, but dissolves on adding water, the solubility increasing on adding water up to a certain point and then diminishing. "II. Glutenin. Characteristics of a proteid which can be dissolved only in dilute acids or alkalies are necessarily very few in number. * * * * It (is) probable that glutenin is slightly soluble in water and alcohol, especially if these are warmed. "III. Edeslin, a globulin belonging to the vegetable vitellins, soluble in saline •solutions, precipitated therefrom by dilution and also by saturation with magnesium sul- phate or ammonium sulphate, but not by saturation with sodium chloride. Partly pre- cipitated by boiling but not coagulated at temperatures below ioo . "IV, Leucosin, an albumin coagulating at52°; unlike animal albumin in being precipitated on saturating its solution with sodium chloride or magnesium sulphate. It is not precipitated on completely removing salts by dyalysis in distilled water. "V. A proteose, precipitated (after removing the globulin by dyalysis and the albumin by coagulation) by saturating the solution with sodium chloride, or by adding 20 per cent of sodium chloride and acidifying with acetic acid. "VI. The solution filtered from the solution just described (V.) still contained a proteose-like-body which was not obtainable in a pure state. "The results obtained by us and described at length in our paper*, lead to the con- clusion that no ferment action is involved in the formation of gluten; that but two pro- teid substances are contained in the gluten, the gliadin and ihe glutenin, and that these exist in the wheat kernel in the same form as in the gluten, except that in the latter they are combined with water in an amount equal to about twice the weight of the water-free proteids." *Am. Chem. Jour., 15, 392, 471. CONCERNING WHEAT AND ITS MILL PRODUCTS. 83 An examination of the characteristics of these proteids as described above, and more fully in the publication cited, led to the belief that all nongluten nitrogen will be dissolved from wheat meal by thoroughly ex- tracting with 10 per cent salt solution, and that the gluten nitrogen will remain undissolved. The first method attempted for the separation of these two classes of proteids was to place two grams of the material in a 500 c. c. Kjeldahl flask, mix thoroughly by shaking with a small quantity of 10 per cent salt solution, then adding the remainder of 100 c. c. of the liquid. The con- tents of the flask were shaken at intervals for three hours and then filtered on a 10 c. m. filter of good quality, washing four times with 25 c. c. of salt solution each time. The filter and contents were then carefully re- turned to the flask and the nitrogen in them determined by the usual Gunning modification of the Kjeldahl method. Duplicates agreed closely. The results were, however, unsatisfactory as appears from the following : Different strengths of salt solution were used on a sample of straight flour containing 1.82 per cent of total nitrogen, with results as indicated below. Per cent in sal solution 15 10 5 2^ 2 \]/ 2 1 ^ Per cent nitrogen • 1.56 1.50 1.43 1.33 1.30 1.29 1.29 1.30 Similar results were obtained on another sample of flour. Comparison was made on a complete series of mill products by using a 10 per cent and a 1 per cent salt solution. The per cent nitrogen in each residue, based on the original 2 g. of substance is shown. Patent Flour. Straight Hour. Low Grade. Dust Room. Ship Stuff. Bran. Wheat. 10% salt solution I % salt solution 1.28 I.07 i-45 1-25 I.92 I.77 I.49 1-43 I.9I I.78 I.63 I.60 1-34 Difference .21 .20 •15 .06 •13 •03 •17 A further trial was made in which each of another series of mill products was washed fifteen times with a 1 per cent salt solution. The comparison with the results from washing four times, using the same strength of salt solution is shown in the next table. Figures show per cent nitrogen in undissolved residue based on weight taken for analysis. 84 ARKANSAS AGRICULTURAL EXPERIMENT STATION. Patent Flour. Straight Hour. Low Grade. Dust Room. Ship Stuff Bran. 1. 6l •94 Wheat. Washed four tim p s Was; ed fifteen times.. .91 1.28 .98 I.52 1.19 I.42 .87 I.56 •94 i-39 •95 Difference .24 •3° •33 •55 .62 .67 •44 The filtrate at the end of the fifteenth washing still showed the presence of proteids. This last trial seems to indicate that a considerable quantity of the gluten of flour is removed by continued washing and that the same will occur to a considerable extent in the mechanical washing out of crude gluten. The long time required for this washing may have brought about some change in the form of proteids such as would tend to make the insol- uble more soluble. Perfectly concordant though not so marked results were obtained by less protracted washing. The foregoing method of separating the gluten from the nongluten having been found subject to such serious objections, the following method, which it was believed would obviate the difficulty to a considerable extent, was substituted for it. Two grams of the material to be examined are put into a 200 c. c. graduated flask and after mixing thoroughly with a 10 per cent salt solution the flask is filled to the neck with the same liquid. The contents of each flask are then shaken at intervals of ten minutes for one hour. At the end of this time the flask is filled to the mark, the contents well mixed and the whole is allowed to remain quiet for two hours. At the end of this time the supernatent liquid in the flask is filtered through a dry filter into a dry flask. If the filtrate is not perfectly clear the first portion is refiltered through the same filter. When sufficient clear filtrate has been collected exactly 100 c. c, measured in a pipette, are run into a 500 c. c. Kjeldahl digestion flask of the usual pear shaped form with long neck. To this solution 20 c. c. of the usual sulphuric acid used for Kjeldahl work are added. The contents of the flask are brought to a gentle boil and when the water has been driven off and the acid has quit foaming, the sulphate of potash is added and the digestion completed. Results obtained by this method agree quite closely with those of the preceding method when using the same strengh ot salt solution and washing four times. The amount of nitrogen obtained in the above process is computed to per cent on one gram of substance. If our hypothesis be true that the CONCERNING WHEAT AND ITS MILL PRODUCTS. 85 salt soluble nitrogen compounds correspond to those not gluten, and those only, the difference between the per cent of nitrogen in the salt extract and the per cent of total nitrogen in the sample will give the per cent of nitrogen which is present in those proteids which together form gluten, and this per cent of nitrogen multiplied by 5.7 will give the theoretical amount of gluten in the material examined. Numerous estimates of gluten in different grades of flours and wheat meal have been made by the above described chemical method, and on corresponding samples by determining the amount of nitrogen in crude gluten washed out by the usual mechanical process. The mechanical washing out of the gluten has been done entirely by Mr. Moore with great care. The amount of gluten found by the above described chemical method is higher, and in the lower grades of flour much higher than by the usual mechanical method followed by a nitrogen determination. That is, by computing the true gluten from the nitrogen contents of the crude gluten obtained. The proportion of impurities in the crude gluten, especially that from low grade flours is also large, so that decidedly erro- neous results would be obtained by the mechanical method unless the crude gluten be submitted to analysis and the impurities determined. When considering the large amount of time and labor involved this is de- cidedly objectionable. Furthermore, the question still remains, does this give the true gluten in the sample examined? It will be shown later that the chemical method proposed above gives results which are decidedly too low, making the error for the gluten obtained by the mechanical method still greater than appeared from the above comparison. The cause of the error can be better explained and more readily understood after a con- sideration of the next topic. DETERMINATION OF THE GLIADIN. An attempt has been made to separate the gliadin of wheat by a quantitative method which can be readily applied to various samples. After some more or less unsatisfactory attempts the following* has been found a more or less ready means of this separation or at least a ready means by which all proteids soluble in hot 75 per cent alcohol can be extracted. One gram of the material to be examined is put into a 500 c. c. Kjeldahl digestion flask. 100 c. c. of 75 per cent alcohol, free from *Since the method here described has been in use, the second edition of Chemistry and Analysis of Wheat, Flour, etc., by William Jago, has been received. In it (p. 78Q) he describes a method for determin- ing proteids soluble in alcohol, which perhaps requires a little less labor than the one proposed in the text, but it is quite certain from comparisons made that results for gliadin obtained in that way will be much too low. 86 ARKANSAS AGRICULTURAL EXPERIMENT STATION. nitrogen compounds, are added and after shaking thoroughly the flask is placed upright upon a suitable sized ring of an ordinary water bath. 1 The one used here contains holes for eight flasks. The water bath is heated so as to keep the temperature of the alcohol just below its boiling point. The contents of the flasks are shaken at intervals during the first hour. They are then allowed to remain quiet for one hour, after which the hot, clear liquid can be decanted onto a 10 c. m. filter of good quality. 25 c. c. of hot alcohol are then added to the residue and it is again placed upon the flask for ten minutes before filtering. This is repeated six times. It has been thought best in some instances to completely remove all alcohol from the flask after the last washing and the adding of the well drained filter. This may be readily done by placing the flask on or within the water bath and driving out the vapor by the assistance of a syringe bulb connected with a glass tube or by connecting the glass tube with an ordinary Rich- ards' air blast. The presence of the alcohol has sometimes given trouble during the subsequent digestion in removing a large part of the acid by volatilization of the resulting compound. After the alcohol has been removed the nitrogen is determined in the usual way, care being taken that all particles adhering to the neck of the flask are washed down by the acid and digested. It is necessary in this instance to determine the nitrogen in the filters used and deduct it from the results. The difference between the total nitrogen and the nitrogen thus obtained gives the per cent of nitrogen in the alcohol extract. This also includes amides as will be shown later. A more ready method of obtaining the nitrogen contents of the alco- hol extract is to collect the filtrate directly into a Kjeldahl flask. Place the flask on a sand bath and properly adjust it to a Leibig condenser. The greater part of the alcohol can thus be distilled off in a short time without fear of accident. The last portion of the liquid may be readily removed by placing the flask on a boiling water bath and inserting into the neck a glass tube connected with a filter pump or air blast. By using one of these for each of two flasks a single water jet is made to do double duty. The neck of the flask connected with the blast should be allowed to drop nearly to the horizontal. After evaporating to dryness the nitrogen is determined in the usual way. Osborne and Voorhees suggest, as already noted, that it is possible that glutenin is slightly soluble in hot water and alcohol. There is always a greater or less cloudiness to the liquid when the alcohol extract, obtained as described^above, becomes cold. Among mill products this increases CONCERNING WHEAT AND ITS MILL PRODUCTS. 87 gradually from the finest flours to the bran. Pure germ, when extracted with hot alcohol, gave an extract which was very clouded, though the amount of proteid in solution by no means equaled the amount of gliadin which has been found in an equal amount of cold, perfectly clear, alcohol solution. It is possible that a proteid having this characteristic may exist in the germ. The general characteristics of this portion of the grain differ so greatly from the remainder that it seems quite possible that the proteids of the two portions should differ. A sample of the pure handpicked germ when submitted to the methods for separation of proteids which have been described above gave the following results: The total proteids (NX5.7) were 37.55 percent. Those soluble in salt solution were 15.33 per cent and those soluble in hot 75 per cent alcohol were 2.85 per cent. Another sample of germ contained 36.02 per cent of total proteids. The ether extracts in the two samples were 13.85 and 14.38 per cent respectively. THE PROTEOSE. On comparing the use of a 10 per cent and the use of a 1 per cent salt in the methods described for the determination of the salt extract it was found that, as indicated by the first method, there was a notably larger extract by the 1 per cent than by the 10 per cent salt solution, and a much greater decrease was found when a 20 per cent solution of salt was used. Thus a sample of low grade flour gave the following results : One per cent salt extract contained .66 per cent nitrogen, 10 per cent salt extract contained .48 per cent nitrogen, 20 per cent salt extract contained .20 per cent nitrogen to each gram of material extracted. With the hope of finding the true cause of this feature of the ques- tion a considerable quantity of perfectly clear 1 per cent salt extract of wheat meal was obtained. To this a sufficient quantity of dry salt was added to make a 10 per cent solution. A considerable precipitate was produced and this was found to be largely soluble in 75 per cent alcohol in a clear solution of which proteids were readily detected. If the proteids, or a portion of them, which are soluble in salt solu- tion are insoluble in alcohol they should be precipitated by the addition of alcohol. When 50 c. c. of the clear, filtered 1 per cent salt extract were mixed with sufficient strong alcohol to make the resulting mixture contain about 75 per cent, a considerable white flocculent precipitate was produced, which soon settled, giving a supernatent clear liquid. This filtered rapidly and gave a perfectly clear filtrate. The rapidity of flocculation of OS ARKANSAS AGRICULTURAL EXPERIMENT STATION. the precipitate was increased somewhat on heating. The concentrated filtrate gave strong biuret reaction. In like manner a marked biuret re- action for proteids was obtained by concentrating ioo c. c. of alcohol filtrate when the added alcohol was such as to make 90 per cent of alcohol in the mixture. In following out this line of investigation, a solution was made by mixing 100 grams of wheat meal with 500 c. c. of 1 per cent salt solution, shaking at intervals for one hour and filtering at the end of three hours. The proteids insoluble in 75 per cent alcohol were precipitated from 40 c. c. of this perfectly clear filtrate by adding alcohol to make a mixture of the desired strength. An aliquot portion of the resulting clear alcoholic fil- trate, corresponding to 20 c. c. of the original salt solution, was evapo- rated to dryness in a Kjeldahl flask and a determination made of the amount of nitrogen. Similar nitrogen determinations were made when a 10 per cent, and later a 15 per cent salt solution was used for extracting like quantities of the same wheat. In this manner is found the number of milligrams of nitrogen in the nitrogen compounds soluble in alcohol from 20 c. c. of the salt solutions of the various strengths. Determinations of the total nitrogen contents of each of these salt solutions was also made and computed to milligrams in each 20 c. c. of solution. The results of both of these series of determinations are shown below. Alcohol Soluble Total Nitrogen. Nitrogen, m. g. m. g. I per cent salt solution 19.48 9.7 10 per cent salt solution 18.6 8.8 15 per cent salt solution 16.2 7.6 It was found later that a part of this alcohol soluble nitrogen is from amides, but the amount of amides in the wheat was by no means sufficient to account for the whole of the nitrogen thus obtained, and furthermore, abundant indications of proteids were found in each case by suitably con- centrating the alcoholic filtrate and applying the biuret test. A further comparison of the extracts made by 1 per cent and by 10 per cent salt solutions was made as follows : Salt extracts were made in 200 c. c. measuring flasks as already described, except that four grams of the material were used so that 50 c. c. of the extract would correspond to one gram of the sample. This quantity of extract was mixed with 250 c. c. of strong alcohol and allowed to stand over night. Nitrogen was then determined in both the filtrates and the precipitates with the following results : CONCERNING WHEAT AND ITS MILL PRODUCTS. 89 Precipitated by Alcohol. Per Cent Nitrogen. I per cent salt solution 21 10 per cent salt solution 23 Soluble in Alcohol. I percent salt solution .42 10 per cent salt solution 27 A similar trial on a sample of ship stuff gave results as follows: Precipitated by Alcohol. Per Cent Nitrogen. 1 per cent salt solution 31 10 per cent salt solution 31 It seems clear that the difference in amounts of nitrogen compounds removed from wheat by i per cent and by 10 per cent salt solutions is due to such as are soluble in 75 per cent alcohol. Filtering hot did not ma- terially affect the results. A strong alcoholic solution of wheat proteids was made by mixing the meal with cold 75 per cent alcohol. On pouring this clear extract into 1 per cent salt solution a precipitate was produced which, when filtered off, gave a perfectly clear filtrate. Proteid in considerable quantity was detected in this liquid by various reactions. Furthermore, the liquid was found to give the reactions characteristic of proteoses: Not coagu- lated by heat ; a precipitate with nitric acid which disappears on warm- ing; a like reaction with potassium ferrocyanide and acetic acid; precipi- tation by 20 per cent sodium chloride and acetic acid. Authorities* also state that proteoses are precipitated by alcohol. Either this proteid is somewhat soluble in alcohol or it is the result of the decomposition of a proteid which is soluble in that liquid brought about by mixing with the 1 per cent salt solution. If it be the latter, what is the explanation of the alcohol soluble portion of the salt extract ? When the a'cohol solution of this proteid is concentrated it also exhibits the properties of proteoses mentioned. When this alcohol solution of the salt extract is concentrated somewhat it exhibits the character of gliadin solutions in alcohol in that it is precipitated either by the addition of water or of strong alcohol. A sample of fresh gluten was treated with hot 75 per cent alcohol and 10 c. c. of a resulting concentrated extract were poured into 90 c. c. of 1 per cent salt solution and a precipitate formed. This on the following morning was filtered off and, by sprinkling a little pure, fine animal charcoal on the wet filter, a perfectly clear filtrate was obtained. This filtrate con- tained a proteid exhibiting the same proteose reactions mentioned above. *Chittenden, Digestive Proteolysis, p. 62; Hammarsten, Physiological Chemistry, p. 26. 90 ARKANSAS AGRICULTURAL EXPERIMENT STATION. Some months previous a sample of gliadin had been prepared, at least nearly pure, by precipitating the concentrated 75 per cent alcohol solution with absolute alcohol, and washing well with alcohol and ether, after which it was dried in vacuum over sulphuric acid. A 75 per cent alcohol solution of this was prepared, which, when poured into a con- siderable quantity of 1 per cent salt extract gave the usual precipitate. A clear filtrate, obtained without the use of animal charcoal again exhibited the proteose reactions. On a succeeding page (p. 95) is given a series of results obtained on about twenty samples of different wheats and parts of wheat in which it is shown that when like amounts of wheat or its mill products are treated under the same conditions with equal amounts of 1 per cent salt solution, the amount of alcohol soluble proteid removed from the wheat in the 1 per cent salt solution is practically identical. Many results, which it is thought unnecessary to give, show that the same would have been true if 10 per cent salt solution had been used, except that the quantity thus extracted would have been less. There is a great variation in the amounts of the other nitrogen compounds contained in these various samples. The only reasonable explanation of these facts seems to be that an alcohol soluble proteid which is slightly soluble in 1 per cent and less in 10 per cent salt solution exists in considerable quantities in the wheat. It seems evident that this proteid is gliadin and it appears from the behavior described that gliadin is not changed when it is dissolved in salt solution but that it remains gliadin. With the exception of being readily soluble in 75 per cent alcohol and but slightly soluble in weak salt solutions, it possesses what have been set aside as the characteristic reactions of proteoses. Apparently it was this body which was found by Osborne and Voorhees in their salt extracts and was designated by them as a proteose and a proteose-like body under captions V. and VI. In its alcohol solution (75 per cent) gliadin has not been found to exhibit the reactions of proteoses with common salt. The addition of large quantities of salt in bulk to such a solution was found not to cloud it in the least either with or without acetic acid. When salt in solution is added a precipitate will be produced but in such cases it seems to be attributable, in part at least, to the dilution of the alcohol with water. It has been pointed out by the authors named above that gliadin is soluble in considerable quantities in pure water but is precipitated from such solution by the addition of a very small quantity of salt. The ex- periments recorded above show that the precipitation is not complete. CONCERNING WHEAT AND ITS MILL PRODUCTS. 91 This solubility of gliadin in salt solutions accounts for the fact that when flour is treated directly with large quantities of salt solution no gluten is formed. It also has an important bearing upon the determination of gluten in wheat or flour by the usual mechanical method of washing away the starch and weighing the residue. Twelve grams of Porter's "standard" flour, from spring wheat, was made into a dough with 10 c. c. of i per cent salt solution and allowed to stand for one hour. It was then tied in a linen cloth and worked between the fingers in one liter of the same salt solution for one hour. It having been found impossible to obtain a clear filtrate from the solution direct it was heated nearly to the boiling point. One hundred and seventy-five c. c. of a nearly clear filtrate from this were evaporated to about 30 c. c. and enough strong alcohol added to make the mixture contain 75 per cent. Ten c. c. of perfectly clear filtrate from this showed much cloudiness on adding a few drops of a solution of phospho-wolframic acid which cloudiness precipitated on standing. The remainder of the alcoholic solution when concentrated gave in repeated trials distinct biuret reaction for proteids,* the same rose color being exhibited as when gliadin is treated. It has been already pointed out that the so-called true gluten ob- tained by mechanical washing away of the starch and computing the re- maining proteids from the nitrogen contents of the crude gluten obtained gives results which are much too low when compared with the sum of the gliadin and glutenin in the sample examined. The explanation is here apparent. An indefinite amount of gliadin is dissolved and washed away. In view of this fact the mechanical method of determining gluten in wheat and flour is even more unsatisfactory than has formerly been thought. EDESTIN AND LEUCOSIN. If a perfectly clear 1 per cent salt solution extract of wheat be heated slowly to about 50 c. a cloudiness will begin to appear and if the liquid be kept at about 60 for some time a considerable quantity of flocculent pre- cipitate separates out. If this be filtered off and to the perfectly clear filtrate alcohol be added a still further precipitate occurs, which is less than when alcohol is added to the unfiltered solution. According to the descriptions of edestin and leucosin given by Osborne and Voorhees this is what would be expected if these two proteids are in the alcohol precipitate *The delicacy of the biuret reaction for this proteid may be increased by using a very small quantity (2 c. c.) of the concentrated solution, an equal amount of the strongest caustic potash solution, and, after adding the few drops of copper sulphate, adding aiso about one cubic centimeter of strong alcohol. After shaking the mixture gently the color will be concentrated in the clear alcohol which rises to the top. 92 ARKANSAS AGRICULTURAL EXPERIMENT STATION. of the silt extract. It is difficult to determine what strength of alco- hol will produce complete precipitation of these proteids. From a con- siderable number of trials, the details of which it seems unnecessary to give here, it is believed that a strength of 75 per cent alcohol produces at least nearly complete precipitation, but it does not appear safe to stop short of that strength. It is not safe to increase the strength to 90 per cent for fear of precipitating the gliadin. The readiness with which these proteids can be separated from the liquid in which they are precipitated, suggests that they might be collected in a Gooch crucible, washed, dried and weighed in bulk. The precipita- tion from so large a bulk of liquid would seem to leave them quite pure. At least part of the precipitate caused by alcohol will not be redissolved when the alcohol is decanted and an excess of 1 per cent salt solution added. This change in solubility may be accompanied by a slight change in composition. AMIDES. To ascertain concerning the solubility of amides in 75 per cent alcohol 200 m. g. of asparagin (pure. E. Merck) were dissolved in 50 c. c. of 1 per cent salt solution. This solution was mixed with the usual amount of strong alcohol used for precipitating proteids from a like quantity of solution. A slight precipitate occurred which seemed to become more crys- taline on boiling. The liquid was allowed to cool thoroughly before filter- ing. The filtrate was collected in a Kjeldahl flask and the alcohol removed by boiling and evaporation on a water bath. A considerable quantity of asparagin crystals remained. On determining the nitrogen in the usual manner, a quantity was found equal to that contained in 25.7 c. c. of -^ ammonium hydrate. This is much in excess of the total nitrogen ob- tained from any sample of wheat examined. Allantoin,* another amide of wheat, is also soluble in alcohol. The amides, then, may be assigned to the alcohol solution, whether from the salt solution or from the original sample. In attempting to make a complete separation of the proteids of wheat based upon the amount of nitrogen found, a determination and location of the amides present is important. To that end it is assumed that in the sound, mature wheat all nonproteid nitrogen exists in the form of amides. The "official method" for the determination of the albuminoid nitro- gen has been found deficient for wheat in this respect: It directs, "If the * Watts' Dictionary of Chemistry, Vol. i. 1893. CONCERNING WHEAT AND ITS .MILL PRODUCTS. 93 substance examined consists of seed of any kind, add a few cubic centi- meters of a solution of (potash) alum just before adding the cupric hydrate and mix well by stirring." The following results with and without alum were obtained on a sample of wheat meal. Per Cent Albuminoid Nitrogen. Copper hydrate and o c. c. alum solution 1. 53 Copper hydrate and 5 c. c. alum solution 1.37 Copper hydrate and 10 c. c. alum solution 1.35 Copper hydrate and 15 c. c. alum solution 1.35 Copper hydrate and 20 c. c. alum solution 1. 32 The depth of blue color in the filtrate increased directly with the amount of alum used. That with no alum was almost colorless and that with 20 c. c. of alum had a strong blue tint. When no alum was used the filtrate showed but slight turbidity with a solution of phospho-wolframic acid while the others showed abundant precipitates. As suggested by P. P. Deherain,* phospho-wolframic acid was tried as a precipitant for the proteids, conducting the remainder of the experi- ment as when copper hydrate is used. In a few instances results were obtained which are fairly concordant with those given by the copper hydrate method. Generally, however, in wheat meals and flours the liquid filters badly and it was found almost impossible to obtain a clear filtrate. In later work it was found that when a solution of phospho- wolframic acid is added to a salt extract made as has been described, a precipitate occurs, which, when left over night, gives a clear supernatent fluid which filters readily and leaves a perfectly clear filtrate. On collect- ing this (50 or 100 c. c. with a few cubic centimeters of washings) in a Kjeldahl flask and adding 20 c. c. of concentrated sulphuric acid the water can be readily boiled off, especially if the flask be protected from the naked flame with a thin sheet of asbestos. When the acid ceases to foam it is cooled slightly, sulphate of potash added and the nitrogen determina- tion completed in the usual way. After adding the sulphate the time re- quired for the digestion is but a few minutes. The readiness with which the water may be driven off and the di- gestion completed in this way makes it preferable to determine the nitro- gen in the filtrate when the albuminoid nitrogen is precipitated by copper hydrate as in the official method. The difference between the nitrogen found and the total nitrogen of the sample gives the amount of albuminoid nitrogen with equal accuracy, while the time of digestion is much shortened, *Traite de Chimie Agricole, p. 267. 94 ARKANSAS AGRICULTURAL EXPERIMENT STATION. the danger of breakage is lessened and the necessity for making a correc- tion for the nitrogen in the filters is prevented. The only requirements are that the water and reagents shall be free from an appreciable quantity of ammonia or other nitrogen compounds, and this is equally essential in all Kjeldahl work. AMOUNT OF GLIADIN IN SALT EXTRACTS OF WHEATS AND FLOURS. The results of a separation of the nitrogen compounds in the i per cent extract of a considerable number of samples of wheat, flour, etc., are given below. The separation has been made by the above methods. Precipitation of edestin and leucosin in alcohol of 75-80 per cent strength ; determination of the amide or nonproteid nitrogen in the filtrate after precipitating with phospho-wolframic acid ; estimating the soluble gliadin nitrogen by difference. A systematic arrangement of details of procedure are given on a subsequent page. CONCERNING WHEAT AND ITS MILL PRODUCTS. 95 TABLE SHOWING NITROGEN OF COMPOUNDS SOLUBLE IN ONE PER CENT SODIUM CHLORIDE SOLUTION. Figures show nitrogen in each compound in per cent of one gram of substance examined. ARKANSAS MILL PRODUCTS. Kind of Material. Patent Flour Straight Flour Low Grade Flour Ship Stuff Bran Sifted Dust (outer bran). porter's flours. c , sl « c c V £ o 5 c £ U V r. a at •0 .- is v v a ife H W^ " < •41 .11 •03 •43 •13 •03 •54 .21 •°5 •7i ■31 .10 1. 00 .48 • 2 3 •5° .16 .20 c o ■3 - ~Z o .27 .27 .28 •30 .29 .14 Souvenir (extra patent) 0000 Boss Flour (patent) . Standard Flour (straight) Strong Bakers' Flour Red Dog (low grade) .46 .46 •5° .68 •97 .11 •05 .11 •05 •15 .06 •30 .09 •45 .25 ■30 •3° .29 .29 .27 WINTER WHEATS. Red, Arkansas Red, Arkansas (harvest '94). Currell, Kansas Zimmerman, Kansas White Wheat, Canada Oregon White •72 •3i •5 2 .19 •7i •3° .68 .26 •5° .22 .49 .20 SPRING WHEATS. .12 .IO .09 .12 .07 .07 .29 •23 .29 •30 .21 .22 Red Wheat, South Dakota Red Fife, North Dakota Red Fife, Minnesota .81 •35 .60 •25 .64 .28 • 17 .09 .II .29 .26 •25 An examination of the table will show that when the sum of the ni- trogen of the amides and of the alcohol precipitate is subtracted from the total nitrogen of the salt solution the difference is practically a constant for sixteen different samples of wheat and mill products. The average for these sixteen samples is .28 per cent of nitrogen for one gram of material. This nitrogen is from the gliadin soluble in 1 per cent salt solution under the 96 ARKANSAS AGRICULTURAL EXPERIMENT STATION. conditions of the experiment. Four results vary to a considerable extent from the average of the other sixteen. Of these, one is the sifted dust room contents which consists of the outermost portion of the bran. The nitrogen here obtained is .14 per cent. The nitrogen in the direct alcohol extract of this sample was .36 per cent. Of this, .20 per cent should be credited to amides. The difference, or .16 per cent, represents that from the total gliadin in the material, and shows why a greater amount was not extracted by the salt solution. That gliadin is contained in the alcohol extract from this sample was verified by suitable reactions. Two other samples showing an unusually low difference are white wheats, each of which contains a very low per cent of gliadin. The remaining irregular sample is an Arkansas red wheat of the harvest of 1894. These include all samples which have been examined in this way. The mean difference for all samples, excluding dust, is .27 percent. The foregoing results seem to justify the proposing of a method for the determination of the gluten in wheat and flour based upon the sub- traction of a constant factor from the nitrogen found in a 1 per cent salt solution, which otherwise represents the nongluten nitrogen contained in the material. One per cent salt solution is preferable to a 10 per cent solution, in that it is more satisfactory in certain points of manipulation. Based upon the work done, the provisional factor of .27 per cent is pro- posed. The results indicate that another might be more applicable to a certain class of wheat. The work done is not sufficient to give definite conclusions on that point. The results of the foregoing work may be summed up in the following : METHODS FOR QUANTITATIVE DETERMINATION OF WHEAT PROTEIDS. Total Nitrogen. The Gunning modification of the Kjeldahl method has been used throughout this work. More concordant results have been obtained with one gram of material than with two grams. Nongluten Nitrogen. Put five grams of the material to be examined into a 250 c. c. measuring flask. Add about 15 c. c. of a 1 per cent so- lution of sodium chloride and shake thoroughly. To the resulting homo- geneous mass add enough of the same solution to fill the flask nearly to the neck. Shake the contents of the flask at intervals of ten minutes during one hour. Fill to the mark with salt solution, mix thoroughly and let stand for two hours. Decant the liquid onto a 12^ c. m. dry filter of good quality, leaving the greater bulk of the solid material in the flask. The filtrate will be clouded, but if refiltered through the same filter into a CONCERNING WHEAT AND ITS MILL PRODUCTS. 97 clean flask it will generally be perfectly clear. Determine the nitrogen in 50 c. c. of this extract, noting precautions on page 93. From the per cent of nitrogen thus obtained subtract .27 per cent as corresponding to the ni- trogen obtained from the gliadin soluble in 1 per cent salt solution un- der the conditions prescribed above. The remaining per cent of nitrogen is that corresponding to the nongluten nitrogen in the sample examined. Gluten Nitrogen. This is the difference between total nitrogen and the nongluten nitrogen as obtained above. The gluten nitrogen may also be found by subtracting the sum of the edestin, leucosin and amide nitrogen from the per cent of total nitrogen. Edestin and Leucosin Nitrogen. To 50 c. c. of the clear salt extract, obtained as described above, add, in a Kjeldahl digestion flask of 500 c. c. capacity, 250 c. c. of pure 94 per cent alcohol (188 per cent proof, redistilled). Mix thoroughly and allow to stand over night. Collect the precipitate on a filter (10 c. m.) of good quality, return to the flask and determine the nitrogen, making proper correction for the nitrogen in the filter. If desired, these two proteids may be separated by coagulating the leucosin at 60 c. and precipitating the edestin by adding alcohol to 50 c. c. of the clear filtrate as before. The nitrogen in each precipitate may then be determined. Amide Nitrogen. Precipitate all proteids from 100 c. c. of the clear salt extract obtained as above by adding 10 c. c. of a 10 per cent solu- tion of phospho-wolframic acid, made by dissolving the pure soiid in distilled water. Allow to settle before filtering and determine the nitro- gen in the clear filtrate. (See page 93.) In case of bran, and per- haps immature or sprouted wheat, it may be necessary to add a somewhat larger quantity of the acid solution to produce complete precipitation of the proteids. In such cases the filtrate should be tested by the addition of a few cubic centimeters of the acid. Gliadin Nitrogen. Extract one gram of the material with hot 75 per cent alcohol as described on page 85. From the per cent of nitrogen dissolved by the alcohol subtract the per cent of amide nitrogen. The difference will be the gliadin nitrogen. Glutenin Nitrogen. The difference between the gluten nitrogen and the gliadin nitrogen gives the glutenin nitrogen. Proteids. The amount of the various proteids may be found by mul- tiplying the per cent of the corresponding nitrogen obtained by 5.7. This factor is deduced from the average nitrogen contents of the proteids 98 ARKANSAS AGRICULTURAL EXPERIMENT STATION. of wheat as found in a large number of analyses made by Osborne and Voorhees. It undoubtedly approximates much nearer the truth than the factor 6.25. Wheat for the above work should be ground so that the endosperm shall pass through a sieve having circular holes of J4 millimeter in diameter. The bran of the grain, being in thin flakes will be sufficiently fine if made to pass through a sieve with circular holes one milimeter in diameter and the work of pulverizing will be greatly lessened. The resulting parts must be thoroughly mixed. The error due to the presence of the undissolved meal in the measuring flask used for the determination of the salt extract is so small that it may generally be neglected. If desired, the flask may be readily remarked for the work by adding to the usual weight of meal in the flask exactly 250 c. c. of the salt extract. In this case care must be taken to wet the meal thoroughly with not more than 25 c. c. of the liquid, after which the remainder of the meal may be added. SEPARATION OF THE PROTEIDS OF CERTAIN WHEATS AND FLOURS. Following the plan of separation outlined above a proximate analysis has been made of the nitrogen compounds of certain flours and other mill products and of a few samples of wheat grown in different sections of the country. They are given mainly to illustrate the variations in the relative amounts of the different proteids. That this variation may be more clearly seen, one of the tables shows the nitrogen of the proteids in per •cent of the total nitrogen of the sample. The extension of such anylitical ■work to a large number of samples of wheats and flours of different •characters is necessary before definite conclusions can be drawn as to the relation which the different proteids have to those characteristics, and inas- much as it is a new field of labor, the outcome of such work cannot be do retold. It has been frequently stated that bran contains no gluten. In the analysis of the sample of bran shown in the table both gluten proteids are shown to be present in considerable quantity. A portion of this gliadin is from adhering endosperm. However, the pure sifted dust, which con- sists of the outermost portion of the grain, contains a small amount of gliadin. The explanation of the formation of gluten by Dr. Osborne in- dicates that the presence of the gluten proteids in bran and the nonforma- tion of gluten in the usual mechanical method of separation are perfectly CONCERNING WHEAT AND ITS MILL PRODUCTS. 99 consistent. The true explanation seems to be that the woody fiber of the bran prevents the uniting of the gluten particles into the gluten mass characteristic of flour and wheat meal. The variation of the nitrogen compounds among different mill products from the same mill are interesting. Among these the gradual in- crease of amides, of edestin and leucosin and of glutenin from the finest flour to the bran and the corresponding gradual decrease of gliadin are worthy of note. In the series of mill products of which the analyses of the ashes were made, all were from the same wheat. It is pretty certain that those in this series of analyses are not all from the same wheat, which accounts for certain minor variations. All were taken from the mill at the same time and were of recent grinding. As between the patent flours from winter and from spring wheat the equal amounts of gliadin and the great difference in the amounts of glutenin are suggestive. There may also be a hidden meaning in the very low proportion of gliadin found in the two samples of white wheat examined. A knowledge concerning this and other matters relating to this subject may give information which will be useful in the blending of wheats and flours to improve the quality of the latter. This is now prac- ticed to some extent by bakers and millers upon their knowledge of the general physical characters of the material and it is believed by many to be attended with good results. 100 ARKANSAS AGRICULTURAL EXPERIMENT STATION. TABLE SHOWING NITROGEN OF NITROGEN COMPOUNDS OF WHEAT IN PER CENT OF TOTAL NITROGEN PRESENT. ARKANSAS MILL PRODUCTS. Kind of Substance. Patent Flour Straight Flour Low Grade Flour Ship Stuff Bran Sifted Dust Z M 3 O 8.1 8.6 ii. 8 17.2 26.3 26.5 .2Z O O 64.2 S4-o 5°-5 46.2 23-7 11. 8 2fr O 27.7 47-4 37-7 36.6 50.0 61.7 ££ ,c c V> 3 an 6.4 7.0 9-5 13.0 17.8 11.8 < 1.7 1.6 2-3 4.2 8-5 14.7 porter's flours. Souvenir 0000 Boss Flour Standard Flour Strong Bakers' Flour Red Dog 7.8 7-4 9-3 14.7 26.3 92.2 92.6 90.7 85-3 73-7 5°-7 51.8 5i-3 45-5 27-5 4i-5 40.8 39-4 39-8 46.2 5-4 5-i 6.6 "•3 16.9 2.4 2-3 2.7 3-4 9.4 WINTER WHEATS. Red, Arkansas Red, Arkansas (1894) Currell, Kansas Zimmerman, Kansas ... White Wheat, Canada Oregon White Wheat.. 17-3 13.2 16.7 16.5 20.6 18.7 82.7 86.8 83-3 83-5 79-4 81.3 48.4 45-7 43-2 42.4 34-o 34-7 34-3 41. 1 40.1 41. 1 45-4 46.5 12-5 8-7 11. 4 "•3 15.6 13-9 4.8 4-5 3-4 5-2 5.0 4-9 SPRING WHEATS. Red Wheat, South Dakota Red Fife, Minnesota Red Fife, North Dakota.... 15-5 18. 1 17.4 S4-5 81.9 82.6 42.6 37-9 36 4 42.0 440 46.8 10.4 13.0 12.8 5.0 4.6 CONCERNING WHEAT AND ITS MILL PRODUCTS. 101 TABLE SHOWING PER CENTS OF PROTEIDS IN WHEATS AND FLOURS. ARKANSAS MILL PRODUCTS. Kind of Material. Patent Flour Straight Flour Low Grade Flour Ship Stuff Bran Sifted Dust ids. c a a B s •S £ a ■a u S - 3 .2 3 u O O 9.86 9.06 6-33 2-73 10.66 9-75 5-76 3-99 12.54 11.06 6-33 4-73 13-57 11.23 6.27 4.96 15-39 "•34 3.65 7.69 7-75 5-7o .91 4-79 •63 •74 1.20 1.77 2.74 .91 porter's flours. Souvenir 0000 Boss Flour Standard Flour , Strong Bakers' Flour Red Dog 11.69 10.77 12.43 11. 51 12.86 11.69 15.16 12.94 15.16 11.17 1 5-93 6.44 6.16 6.90 4.16 WINTER WHEATS. Red Wheat, Arkansas Red Wheat, Arkansas (1894) Currell, Kansas Zimmerman, Kansas White Wheat, Canada Oregon White Wheat 14.14 12.48 I5-05 13-17 8.04 8.21 4.84 5-°7 5.08 6.04 7.01 11.69 6.84 4.85 10.83 5-70 5-13 12.54 6.50 6.04 1 1. 00 5-59 5-41 6.38 2.74 3- 6 4 6.67 2.85 3.82 .63 •63 .86 1. 71 2.57 1.77 1.08 1. 71 1.48 i- 2 5 1. 14 SPRING WHEATS. Red Wheat, South Dakota Red Fife. Minnesota Red Fife, North Dakota 19.15 l6.I9 8.I5 12.31 IO.O9 4.67 ; II. 12 9.18 4-05 8.04 5-42 S- l 3 2.00 1.60 1-43 ACKNOWLEDGMENTS. Thanks are due the following for samples of wheat and flour' for this work: The L. C. Porter Milling Company, Winona, Minn.; Prof. E. A. Burnett, Brookings, S. D. ; Prof. C. B. Waldron, Fargo, N. D. ; Mr. Robert Dawson, Paris, Ont. ; Prof. C. C. Georgeson, Manhattan, Kas. ; Prof. H. T. French, Corvalhs, Ore., and Mr. Andrew Boss, St. Anthony 102 ARKANSAS AGRICULTURAL EXPERIMENT STATION. Park, Minn. Through the kindness of the late Fayetteville Milling Com- pany and of Mr. B. F. Johnson and his son, the data of the various test runs recorded in this bulletin and the various samples of mill products used for analysis, have been procured. The large amount of analytical and other routine labor which have resulted in that portion of the bulletin relating to the separation of the proteids of wheat, and the making of certain analyses recorded in Part L, have been greatly facilitated by the earnest cooperation of Mr. J. F. Moore, who has faithfully performed all duties assigned to him. G. L. Teller. Chemical Laboratory, Arkansas Experiment Station. CONCERNING WHEAT AND ITS MILL PRODUCTS. 103 APPENDIX. Since the foregoing pages were sent to press an effort has been made to determine whether or not the proteose bodies found by Dr. Osborne 1 in the water or salt solution extracts of oats, rye and barley, and by Drs. Chittenden and Osborne 2 in similar extracts of maize, may be attributable to characteristics of the alcohol soluble proteids of those grains, such as have been pointed out as belonging to the gliadin of wheat. To that end extracts of each were made with 75 per cent alcohol and with a 1 per cent salt solution. Of each clear filtered salt solution extract 25 c. c. were mixed with 125 c. c. of 94 per cent alcohol. The resulting precipitates were filtered off and the clear filtrates were each found to possess the following reac- tions in common with solutions prepared from wheat in like manner : A precipitate upon dilution either with water or with absolute alcohol. A precipitate or cloud with phospho-wolframic acid, which precipitate dis- solves on warming and reappears on cooling. Nitric acid does not pro- duce a precipitate in such dilute solutions. Of each alcohol extract 25 c. c. were mixed with 125 c. c. of 1 per cent salt solution. A clear filtrate from the resulting mixture gave in each case reactions for proteids. The resulting precipitates dissolved more or less completely on warming and reappeared on cooling. With nitric acid this solution from wheat gave a cloud which quickly disappeared on warm- ing. With the rye solution no change was seen* until the liquid was cooled with ice. A dense cloud then appeared while a similar tube of the liquid without the acid remained perfectly clear. The cloud disappeared on adding strong alcohol as well as on warming. In the solution from barley a similar but less marked cloud was obtained on cooling with ice. No pre- cipitate with nitric acid was obtained in these dilute solutions from either corn or oats. Certain other reagents gave, in each case, precipitates which dissolved on warming and reappeared on cooling. A nearly clear water solution obtained by mixing the 75 per cent alcohol extract of corn with a large 1. Conn. Exp. Sta. Reports, 1890 and 1894. 2. Amer. Chem. Jour. Vols. XIII and XIV. 104 ARKANSAS AGRICULTURAL EXPERIMENT STATION. excess of water, gave a precipitate with nitric acid which did not dissolve, but increased on warming. When, however, a quantity of strong alcohol was added to the liquid the precipitate immediatelv dissolved. With each grain, including wheat, the clear alcohol extract of the meal gave precipitates in the cold with phospho-wolframic acid and with tannic acid, each being in solution in 75 per cent alcohol. In each instance the precipitate dissolved on warming and reappeared on cooling. A similar precipitate was given with nitric acid and the liquid became more or less yellow on boiling. As shown above, the compounds of these proteids with nitric acid are very soluble in dilute alcohol. With phospho-wolframic acid the cloud which at first dissolved reappeared when the liquid was kept near its boiling point for a short time. In the alcohol extract of corn the precipitate with tannic acid is slight, even with much reagent. It is very readily seen if the strong solution of proteid be diluted with an equal bulk of 75 per cent alcohol, sufficient reagent added and the whole cooled with ice. These facts, in connection with certain others pointed out on previous pages of this bulletin, support the belief that the proteose bodies which have been found in the water or dilute salt extracts of these various grains are really the alcohol soluble proteids, small quantities of which have been carried into solution and exhibit their characteristics unchanged. Further- more, these alcohol soluble proteids are seen to possess certain properties which have been thought to be characteristic of proteoses. • G. L. Teller. Fayetteville, Ark., October 3, 1896. 3. Physiological Chemistry, Charles, (1884) p. 117. Physiological Chemistry, Ha'mmarsten, Mandel, (1893) p. 25. Dige.tive Proteolysis, Chittenden, (1894) p. 62. Watts' Dictionary of Chemistry, (1894) Vol. IV, p. 331.