63 63 63 64 64 65 65 66 Bosworth & Wood.... Buffalo Cereal Company. Chapin & Co...... Cypher's Incubator Company. Dayton Milling Company. D. A. de Lima & Co.. Fall Creek Milling Company. Albert A. Keene........ Henry Neff....... Oneonta Milling Company. R. C. Rathborne.... Ross Brothers Company. W. H. Small & Co.... J. E. Soper & Co.... 66 66 66 67 67 67 67 67 68 68 68 69 69 69 Microscopical examination-Continued. Histological features of some cattle-food constituents-Continued. ILLUSTRATIONS. PLATE I. Fig. 1.-Seed coat of charlock. Fig. 2.-Cross cells of seed coat of rye. Fig. 3.-Cross cells of seed coat of wheat. Fig. 4.-Aleuron layer of wheat. Fig. 5.—Epidermal layer of seed coat of common pigweed. Fig. 6.-Epidermal layer of seed coat of rough pigweed. II. Fig. 1.-Epidermal layer of seed coat of cottonseed. Fig. 2.-Palisade layer of seed coat of cottonseed. Fig. 3.-Perisperm layer of seed coat of cottonseed. Fig. 4.—Seed coat of wild bergamot. Fig. 5.-Sclerenchymatous cells from seed coat of flaxseed. Fig. 6. Pigment cells of flaxseed.... III. Fig. 1.—Epidermal layer of sorrel seed. Fig. 2.—Epidermal layer of IV. Fig. 1.-Epidermal layer of seed coat of cow herb. Fig. 2.-Beaded Fig. 6. 86 86 V. Transverse sections of seeds of species of genus Plantagoa. a On Plates V and VI the name Decaisne is by mistake printed "Ducaisne." 6 395 COMMERCIAL FEEDING STUFFS OF THE UNITED STATES: THEIR CHEMICAL AND MICROSCOPICAL EXAMINATION. INTRODUCTION. Extensive investigations on commercial feeding stuffs have been conducted by a number of experiment stations, in connection with the enforcement of the feeding-stuff laws in the various States. These laws, however, usually require a guaranty as to fat and protein only, and consequently the examinations by the stations have been in most cases limited to these two constituents. In a few cases determinations have also been made by the stations of ash, crude fiber, and nitrogen-free extract by difference, but practically ro attempt has been made to determine any of the various carbohydrates that constitute the so-called nitrogen-free extract. From a scientific as well as practical point of view a more complete analysis seemed desirable, as such data would give a better idea of the true composition of a stock food, and thus make possible a fairer comparison of the relative feeding values of the different varieties. In addition to the chemical analyses, a microscopical examination of the stock foods was made by B. J. Howard, chief of the microchemical laboratory, and his report is appended. CHEMICAL EXAMINATION. COLLECTION OF SAMPLES. During the spring of 1904, arrangements were made with the experiment stations of New York and Massachusetts whereby their representatives sent samples of the various stock foods collected by them to this Bureau. Several hundred samples were sent and upon receipt were carefully bottled and corked. If they contained an excessive amount of moisture, they were dried in bulk before being bottled. A small amount of the original sample was reserved for microscopical examination, the remainder being ground fine, passed through a sieve with circular holes 1 millimeter in diameter, and rebottled. METHODS OF ANALYSIS. In the analysis of these foods, the following determinations were made: Moisture, ash, ether extract, crude protein, crude fiber, starch, sucrose, reducing sugars, and pentosans. The methods used for moisture, ash, ether extract, crude protein, and crude fiber are the official methods of the Association of Official Agricultural Chemists.a The methods for pentosans and starch are those provisionally adopted by this association, and the methods for determining sucrose and reducing sugars those used by the miscellaneous laboratory for determining these constituents in most cattle foods and forage crops. These methods are as follows: DETERMINATION OF PENTOSANS. (1) PURIFICATION OF PHLOROGLUCOL. Heat in a beaker about 300 cc of hydrochloric acid (specific gravity 1.06) and 11 grams of phloroglucol added in small quantities at a time, stirring constantly until it has almost entirely dissolved. Some impurities may resist solution, but it is unnecessary to dissolve them. Pour the hot solution into a sufficient quantity of the same hydrochloric acid (cold) to make the volume 1,500 cc. Allow it to stand at least over nightbetter several days-to allow the diresorcol to crystallize out, and filter immediately before using. The solution may turn yellow, but this does not interfere with its usefulness. In using it, add the volume containing the required amount to the distillate. (2) DETERMINATION. Place a quantity of the material, chosen so that the weight of phloroglucid obtained shall not exceed 0.300 grams, in a flask, together with 100 cc of 12 per cent hydrochloric acid (specific gravity, 1.06) and several pieces of recently heated pumice stone; place the flask upon a wire gauze, connect it with a condenser and apply heat, rather gently at first, and so regulate as to distil over 30 cc in about ten minutes, the distillate passing through a small filter paper. Replace the 30 cc driven over by a like quantity of the dilute acid, added by means of a separatory funnel in such a manner as to wash down the particles adhering to the sides of the flask, and continue the process until the distillate amounts to 360 cc. To the complete distillate gradually add a quantity of phloroglucol (purified if necessary) dissolved in 12 per cent hydrochloric acid, and thoroughly stir the resulting mixture. The amount of phloroglucol used should be about double that of the furfural expected. The solution first turns yellow, then green, and very soon an amorphous greenish precipitate appears, which grows rapidly darker, until it finally becomes almost black. Make the solution up to 400 cc with 12 per cent hydrochloric acid and allow to stand over night. Filter the amorphous black precipitate into a tared gooch crucible through an asbestos felt, wash carefully with 150 cc of water in such a way that the water is not entirely removed from the crucible until the very last. Then dry for four hours at the temperature of boiling water, cool and weigh in a weighing bottle, the increase in weight being reckoned as phloroglucid. To calculate the furfural, pentoses, or pentosans from the phloroglucid, use the following formulas: For weight of phloroglucid (a) under 0.03 gram: Furfural =(a+0.0052)×0.5170 Pentoses = (a+0.0052)X1.0170 a U. S. Dept. Agr., Bureau of Chemistry, Bul. 107, p. 57. |