UNIVERSITY OF ILLINOIS library Class. 2>.(o Book MS 1 Volume Ja 09-20M / r V A PRACTICAL TREATISE ON PURE FERTILIZERS. Digitized by the Internet Archive in 2019 with funding from University of Illinois Urbana-Champaign Alternates https://archive.org/details/practicaltreatis00morf_1 A PRACTICAL TREATISE ON 3 ’ Jj / J PURE FERTILIZERS AND THE > > ) j J j 3 y y y y > y y : y y CHEMICAL CONVERSION ROCK GUANOS, MARLSTONES, COPROLITES, AND THE CRUDE PHOSPHATES OF LIME AND ALUMINA GENERALLY, INTO VARIOUS VALUABLE PRODUCTS. BY CAMPBELL MORFIT, M.D., F.C.S., FORMERLY PROFESSOR.OF APPLIED CHEMISTRY IN THE UNIVERSITY OF MARYLAND. With Twenty-Eight Illustrative Plates , or Construction Plans , drawn to Scale Measurements. LONDON: TRUBNER & CO., 6o, PATERNOSTER ROW, 1873- [All rights reserved.] AK'&l c c < C c . c < c < c c r f ' (I c C c t « C r * < « c r c C T. RICHARDS, 37, GREAT QUEEN STREET, W.C '-D'-rrs PREFACE. in c* c\i 3 E) O CV< This treatise is founded upon the special studies and large professional experience of the author in the technology of the mineral phosphates of lime and alumina. All of its teachings are submitted, there¬ fore, as practical knowledge, setting forth the subject systematically, in its most improved relations to science and econo¬ mics. The illustrations, which, with few ex¬ ceptions, are new, have been drawn large to a scale and as actual construction-plans, so that they may be fully expressive with¬ out long descriptions. Their creditable style ■4 VI PREFACE. is due to the draughting skill of Mr. H. Herbert Lewis, a talented mechanical engineer, who worked out the author’s original designs. London, November nth, 1872. TABLE OF CONTENTS. CHAPTER I. PAGE The General Relations of the Subject - - 1-6 CHAPTER II. The Raw Materials.— Comparative Solubility of the Crude Phosphates. Bone-black ; Bone-ash ; Apatite; Phosphorite ; Spanish Phosphorite; Welsh Phosphorite; German Phosphorite; Russian Phosphorite ; Austrian Phosphorite; Copro- lites ; Wicken Coprolites ; Calais Coprolites ; Rossa or Guaymas Guano ; Sombrero Guano ; St. Martin’s Phos¬ phate ; Marlstones; South Carolina Phosphate ; French Phosphate; Cooperite or Navasa Guano ; Orchila Guano. —Analytical table of the comparative composition of the crude or natural phosphates of Lime.—Sulphuric acid; Brown oil of vitriol; Chamber acids; Table of strengths.—Hydrochloric acid ; Table of strength.—Crude ammonia liquor from coal-gas and bone-black works.— Table of the supply and value of nitrogenous wastes.— Woollen refuse ; Leather clippings ; Dried blood ; Dried flesh ; Carne cozida ; Greaves or cracklings ; Human excrements ; Sewage ; Suggestions for the conversion of the latter into ammonia salts ; Morris and Penny’s pro¬ cess ; J. Berger Spence’s and Dunn’s process.—Sulphate Vlll CONTENTS. of ammonia ; Chloride of ammonium.—Sulphate of po- tassa; Chloride of potassium.—Carbonate of potassa ; Salt of tartar ; Pearl ash.—Lime ; Carbonate of lime ; Chalk ; Whiting ; Hydrated sulphate of lime.—Nitrate of soda - 7-66 CHAPTER III. Chemical Data in Connection with the Raw Materials of Artificial Fertilizers. Tri- or bone-phosphate of lime ; Di- or neutral-phosphate of lime ; Bi- or superphosphate of lime ; Precipitated phos¬ phate of lime ; Colombian phosphate of lime ; Sulphite of calcium phosphate.—Phosphate of magnesia.—Car¬ bonate of lime ; Organate of lime ; Sulphate of lime.— Fluoride of calcium ; Chloride of calcium.—Oxide of iron ; Phosphate of iron.—Oxide of aluminium ; Phos¬ phate of alumina.—Organic matters.—Silica and sand. —Water ----- 67-91 CHAPTER IV. The Grinding and Sifting Apparatus. Burr-stone mills ; Roller-mill ; Chasers ; Revolving sifter ; Blake’s crusher ; Howel-Hannay’s centrifugal mill - 92-107 CHAPTER V. The Plant. Steam-boiler and engine ; Roasting furnace ; Platform and its accessories ; Elevator ; Lift; Acid reservoir ; Mixer ; Stone digestion vats ; Solution vats ; Syphon ; Monte- jus; Precipitation vat ; Drying kiln ; Wash vat; Evapo- CONTENTS. IX rating pan ; Mixing machines ; Carr’s disintegrator ; Poole and Hunt’s mixer - 108-146 CHAPTER VI. The Arrangement of the Factory Plant - -147-152 CHAPTER VII. The Rationale of the Processes for Refining the Crude Phosphates of Lime. Diagram of the progressive operations and their effects - 153-161 CHAPTER VIII. The Manufacture of Precipitated Phosphate of Lime. * First fractional treatment or purge for the removal of car¬ bonate of lime ; Second fractional digestion for the solu¬ tion of the tri-phosphate of lime constituent ; the vacuo- precipitation vats ; the ammonia-generator ; Air-pump ; Filtration in vacuo ; Reclamation of the ammonia-preci¬ pitant for repeated use indefinitely ; Utilization of the purge liquor ----- i62 : 202 CHAPTER IX. The Manufacture of Colombian Phosphate of Lime. First process : The use of whiting as precipitant ; Horizontal sieve ; Composition of the product ; the utilization of the mother-liquor or wash. Second process : The.use of iron and aluminium impurities of the mineral, as precipi- - 203-225 tant X CONTENTS. CHAPTER X. The Manufacture of Di-Phosphate of Lime. Morfit’s process (A) : Porcelain-lined vat ; Morfit’s process (B) ; J. Thomas Way’s process ; Ernest Deligny’s pro¬ cess ; Way’s chloro-phosphate of lime and the method of making it - - - - - 226-276 CHAPTER XI. The Method of Reclaiming the Chloride of Calcium Mother-Liquor in Profitable Forms. As pure chloride of calcium ; as chloride of ammonium and hydrated sulphate of lime by means of sulphate of ammo¬ nia or gas-liquor; by means of sulphate of potassa as chloride of potassium ; by means of phosphate of soda ------ 277-287 CHAPTER XII. The Principles of the Super-Phosphating Processes. The maximum yield by pure tri-phosphate of lime ; the falla¬ cies of the usual methods ; the maximum yield by bone- ash ; by coprolites and marlstones ; Analyses - 288-297 CHAPTER XIII. The Manufacture of Pure “ Super-Phosppiate”. Composition of the products from pure tri- and di-phosphates of lime - -29S-302 CONTENTS. xi CHAPTER XIV. The Manufacture of Pure and Wholly Soluble Bi- Phosphate of Lime. The turbine ; the vacuo-leaching vat - - -303-314 CHAPTER XV. The Manufacture of “ Commercial Super-Phosphate”. Composition of the product from various crude bases.—The wells - - - - - -315-326 CHAPTER XVI. The Manufacture of Horsford-Liebig’s and other Phospfiatic Baking-Powders. The process of manufacture ; the directions for use ; Brown or bran bread ; Bread for gouty patients ; Confectioner’s cakes ; White bread.—The steam evaporating-pan - 327-338 CHAPTER XVII. Gerland’s Sulphite of Calcium-Phosphate. Its composition, properties, and manufacture ; Its uses as a fertilizer; as a disinfectant.—The chemical analysis of the product - ~ 339”3 CHAPTER XVIII. The Chemical Treatment of “Redonda Guano” and “Alta Vela Guano” and Mineral Phosphates of Alumina and Iron generally, for Conversion into Fertilizers. Redonda guano ; Alta Vela crust; A. B. R. phosphate rock ; Analytical table of their comparative composition and value ; Method for converting them into potential ferti¬ lizers ; Digestion vats of stone - 360-377 Xll CONTENTS. CHAPTER XIX. The Mineral Phosphates of Alumina and Iron as Raw Material for the Manufacture of Alum and other Useful Products. Peter Spence’s process for making alum, sulphate of alumina, crude phosphoric acid and phosphates ; J. Berger Spence’s and Peter Dunn’s processes for removing am¬ monia from illuminating gas ; for the manufacture of phosphates of ammonia and lime.— Townsend’s pro¬ cess ------ 378-392 CHAPTER XX. The Mineral Phosphates of Alumina and Iron as Raw Material for Defecating Sewage. Their application in purifying and utilizing town sewage ; Forbes’s processes; Price’s processes; Morfit’s “mother- water” as substitute for Alta Vela and Redonda guanos ; comparative composition of the sewage precipitates ob¬ tained by the use of the “mother-liquor” and sulphuric solution of Alta Vela guano - 393-401 CHAPTER XXI. The Profitable Utilization of the Phosphat-Alumina Precipitate from Sewage as Raw Material for Various Products. For the reclamation of its nitrogenous matter as material for the manufacture of ammonia salts ; as raw material for the manufacture of alum and pure phosphates of alumina and lime ; as aluminate of soda or ready saponifier and common salt.—Phosphate of alumina in the manufacture of sugar ; in dyeing ; as a glaze for pottery - - 402-418 CONTENTS . xm CHAPTER XXII. Special Fertilizers and their Preparations. The physical and chemical structure of soils.—Normal ferti¬ lizer ; Universal Dunger ; Fertilizer for cereal crops; for leguminous plants ; for gramineous crops ; for sugar ; for root crops - - 419-431 CHAPTER XXIII. Formulae for the Chemical Analysis of Phosphatic Materials and Products. The chemical and ethical principles involved.—Instructions for the full analysis of bone-ash and mineral phosphates of lime ; of mineral phosphates of alumina and iron ; of “commercial superphosphate”; of compound ferti¬ lizers ------ 432-484 CHAPTER XXIV. The Commercial Valuation of Crude and Refined Fertilizing Materials - - -485-510 CHAPTER XXV. The Mode of Usin6 Hydrometers and Thermo¬ meters - - ■ “ - 5 II " 5 I 9 CHAPTER XXVI. Acid and Water-Proof Cements and Paints - 520-530 Index -531-546 ERRATA. Page 35.—In the heading of the table, rend “ SO for “SO.” ,, 74.—In the sixth line from the top, read “ O for “ O.” ,, 95.—In the sixth line from the bottom, read “f”for “A” ,, 101.—At the bottom line, read “fig. 3,” for “ fig. 1.” ,, in. —At the eighth line from the top, read “d,” for “o.” ,, 116.—At the fifteenth line from the top, read “g,” for “d.” ,, 120.—At the seventeenth line from the top, read “a a,” for “a A.” ,, 120.—At the twenty-second line from the top, read “ af for “A.” ,, 191.—At the seventeenth line from the top, read for ,, 192.—At the eighteenth line from the top, read “ r,” for “x.” ,, 254.—At the last line, read “bone-ash f for “bone.” A LIST OF THE ENGRAVED PLATES OR CONSTRUCTION PLANS. PLATE 1. ROLLER MILL 2 . REVOLVING SIEVE 3. BLAKE’S CRUSHER 4. HOWEL’S CENTRIFUGAL MILL 5. PLATFORM, LIFT, AND ELEVATOR 6. DETAILS OF LIFT AND ELEVATOR 7. MIXER 8. DIGESTER OR SOLUTION VAT 9. TROLLEY FOR BRINGING UP CARBOYS 10. MONTE-JUS 11. PRECIPITATION VAT ... 12 . DRYING KILN 13. EVAPORATING PAN 14 . ) > CARR’S MIXING MACHINE 15 - ) PAGE ... 5 ... 20 - 35 ... 50 ... 65 ... 80 98 ... no ... 123 ... J40 ... 155 ... 175 ... 195 16. 17- 18. 19 - ground PLAN OF A FACTORY ARRANGEMEN 1 245 BATTERY OF PRECIPITATION VATS, WITH AMMONIA- ( 2& 5 GENERATOR ... ... ... ... | 2 85 VACUUM FILTER, WITH AIR-PUMP AND MONTE-JUS ... 305 XVI A LIST OF PLATES . PLATE 20 . HORIZONTAL SIFTING AND STRAINING MACHINE • • • PAGE 330 21. PUG-MIXER... • • • • • • • • 350 22. SOLUTION VAT COMBINED WITH VACUUM FILTER • • • 370 23 - DRAINERS ... • • • • • • • • • 395 24. SUPER-PHOSPHATE WELLS OR PITS • • • • • • 420 25. FILTERING STANDS • • • • • • • • • 440 26. | ) APPARATUS FOR THE TREATMENT OF MINERAL Phos- 1 f 460 27. j ) PHATES OF ALUMINA • • • • • • ... 1 [480 28. DOUBLE-PAN FOR MAKING ACID-PROOF PAINT ... CEMENT • • • AND 500 X PURE FERTILI Z ERS CHAPTER I. THE GENERAL RELATIONS OF THE SUBJECT. The fructification of soils has its natural pabulum, undoubtedly, in the sewage of cities, towns, and habitations ; and it is de¬ sirable, both as respects agricultural inte¬ rests and the public hygiene, that thoroughly efficient means should be devised for uti¬ lizing this resource judiciously. Until this is done, the food required by growing crops must be supplied through the media of arti¬ ficial fertilizers. The manufacture of these products has become, consequently, an enter¬ prise of great magnitude, which is daily extending its area; so that abundant sup¬ plies of the basis-material are indispens¬ able. Fortunately, the beneficence of Nature 2 PURE FERTILIZERS. vouchsafes to us vast deposits of this basis- material, which she has distributed through¬ out the surface of the globe in the form of mineral phosphates, and as a temporary sub¬ stitute; for .sev/age, while our enterprise and skill may .remain at fault in managing the latter with a perfect facility. # These mineral phosphates consist of the various kinds of “ Rock Guano,” Coprolites, the fossils of Marlbeds, and the minerals Apatite and Phosphorite. The chief and valuable constituent of them is bone-phosphate of lime. In some few in¬ stances, phosphate of alumina is the prevail¬ ing constituent. All of these varieties of the mineral phos¬ phates differ from the typical phosphate of lime, which is bone-ash, in having a very dense, compact physical structure, owing to the peculiar state of aggregation of their che¬ mical elements. These elements vary with the kind of mineral phosphate, but besides tri-phosphate of lime, are commonly water, * Their geological distribution is explained fully in an interesting paper by W. J. T. Dyer and A. H. Church, at pp. 159-185, vol. ii of Practice with Science. THE GENERAL RELATIONS. 3 organic matter, silica, sulphate lime, carbon¬ ate lime, together with aluminium and iron oxides and phosphates. Some of them have only a secondary value as agricultural powers, while the others are objectionable, because they dilute the mass unprofitably. In an¬ other, and far more serious sense, however, their presence impairs the usefulness of the raw mineral ; for the latter, even when powdered finely, is by their cementing action rendered rather passive to decomposing in¬ fluences, and consequently a slow fertilizer. I say slow, because I do not share the opinion of many sagacious chemists, that phosphates of alumina and iron are without fertilizing effect ; nor yet that it is indispen¬ sable to change the chemical structure of the' mineral phosphate of lime in order to give it action as a manure. They have inertia in those respects undoubtedly ; but it is my be¬ lief that the need of phosphoric acid by the growing crops is so great as to give them the energy to draw it from the most difficult source if none easier should be accessible. At the same time the strain which is thus put upon the assimilating powers of the 4 PURE FERTILIZERS . plant must weaken its constitution and im¬ pair the quantity as well as the quality of the harvest. Upon the ground of expediency, therefore, and to economize time, labour, and money, this fault of the mineral phosphates should be corrected by a proper chemical treatment, preliminary to their application to soils. That is, they must not only be finely powdered, but converted into forms which are promptly sensitive to the solvent action of aqueous so¬ lutions of carbonic and organic acids, very dilute acetic acid, ammoniacal and potassic salts, and of the corresponding influences of the soil and plants as exerted during the progress of vegetation. The usual method of destroying the iner¬ tia, or passive condition of mineral phos¬ phates, is to act upon them with sulphuric acid which should convert their tri-phosphate of lime into soluble bi-phosphate. This plan is perfectly sound in principle ; but, on ac¬ count of the slovenly mode of carrying it out generally practised, variable quantities of the raw phosphate remain undecomposed, and, as a consequence, proportional amounts of free sulphuric acid are introduced. J/O/i I'l 1 on the Man u fact are of Fertilizers. ROLLER MILL. FRONT ELEVATION. 7 0 I- .- . I ■ ■ ~t~i—TnT i SCALE OF FEET f— 5 —f- 8 =±= 9 =i= =1 Specially designed for DT Morfits Work oil Fertilizer's. Yii lcent Brooks, Day &,Son, Lith. Flaite 1 Truhner & C?, 60, Paternoster Row. THE GENERAL RELATIONS. 5 Here, then, consequently, are a profligate waste of two materials, a want of uniformity in the product, and a wide extent of dilution, by reason of the sulphate of lime which is formed, to say nothing of the disadvantage of the free sulphuric acid. What is wanted, then, are methods, simple and economical, for changing not merely the physical constitution of the mineral phos¬ phates, but also their chemical temperament, and in such a manner as to convert them into fertilizers at once concentrated and potential. These latter qualities are important, more es¬ pecially on the score of package and freight or transportation charges in extensive coun¬ tries, like the United States of America, where distribution of the products is mostly in small lots, to the interior of scattered and often remote districts. In such cases, the necessary or desirable dilution may be done by the farmer himself, and with suitable as well as inexpensive materials which abound at his door, and thus save him needless out¬ lay. The chemical mind has been very active in suggesting ways of accomplishing the needed 6 PURE FERTILIZERS. improvement. Treatment in furnaces with fluxes, and boiling in pans with salts of dif¬ ferent kinds, in order to render the phospho¬ ric acid constituent soluble, are the methods most commonly met with in books. The use of acids of several kinds, and in varied manner, also constitutes the substance of many recorded processes. But, in most cases, the chemical agent em¬ ployed is either itself an undesirable element to import into the fertilizer, or the mode of use is expensive, by reason of the agent not producing incidentally some tangible result to repay fully its cost. Then, too, there is the bulkiness of the raw phosphate, which renders the usual methods both troublesome and defective in economy. No plan of instruction is equal to the che¬ mical agricultural and commercial require¬ ments of the case which does not remedy these deficiencies. This consideration, there¬ fore, is held paramount in the processes of the following chapters. Self-compensating throughout, they will deliver the products in the most valuable forms with the least pos¬ sible manufacturing expense and waste. CHAPTER II. THE RAW MATERIALS. The raw materials involved in the manufac¬ ture of artificial fertilizers are the animal and mineral phosphates of lime, sulphuric acid, hydrochloric acid, crude ammonia liquor, sulphate of ammonia, chloride of ammonium, sulphate of potassa, chloride of potassium, carbonate of potassa, lime, and nitrate of soda. The sources of the chief class, that is the phosphates, are all natural, the several indi¬ viduals being bone-black, bone-ash, apatite, phosphorite, coprolites, marl-stones, and the “ rock guanos". Bone-Black. This material, known also by the title of “ Animal Charcoal", is made by calcining 8 PURE FERTILIZERS. bones in a manner to drive off all the volatile matters except carbon, which is left with the phosphate of lime. This residue thus formed, when ground to powder, is sold to sugar re¬ finers for decolorizing their solutions. After having been used and “ revived ” several times, its bleaching power has become exhausted, and then it is sold either as a manure or for conversion into “ superphosphate\ It con¬ tains a large amount of organic matter, more particularly when blood has been associated with it in the decolorizing or refining opera¬ tion. Bone-Ash. This is a greyish-white powder obtained by calcining raw-bones, in open vessels, so as to get rid of the moisture, organic matter, and carbon ; as these associates would interfere with the economy and convenience of trans¬ portation from distant countries where cattle abound and are killed for their hides, tallow, and bones. The supplies come mostly from the La Plata Districts of South America, and the Baltic, Mediterranean, and Black Sea ports, where the process of manufacture is conducted so wastefully that the valuable THE RAW MATERIALS. 9 ammonia distillate does not receive any con¬ sideration. The tri- or bone-phosphate of lime in this ash, as well as in the bone-black, is pecu¬ liarly sensitive to the assimilating action of growing crops. For example, one part of its phosphate is soluble in 6800 parts of car¬ bonic water, according to Warrington’s ex¬ periments; and this solubility is even greater when alkaline salts are present. Both the bone-black and bone-ash are such superior fertilizers for direct application to the soil, that it would be profligate to use them as raw material for conversion into “ superphosphate”. So great and growing is the demand for these two materials, that their market price has advanced twenty per cent, within the last few years. Apatite. This is a hard mineral, sometimes crystal¬ lized and at others foliated or conchoidal, which is found generally in thin seams in crystalline or volcanic rocks. It varies in colour from light green to iron-stone red. The principal localities are Norway, Sweden, IO PURE FERTILIZERS. Switzerland, Bohemia, Saxony, Bavaria, Canada, New York, and New Jersey. In order to obtain a fair average sample, it is necessary to grind an entire ton, owing to the difficulty of excluding foreign minerals in mining it. According to Voelcker, the Norway apatite is always free from fluoride of calcium, which is present, usually, in the other varieties. The Canadian apatite is crystallized, crys¬ talline, granular, and massive, and of a sea- green, olive green, greyish, or reddish colour. It abounds, according to T. S. Hunt, in the Laurentian limestones of North Elmsley and North Burgess, where it forms numerous beds eight to twenty-four inches thick and about ten feet broad. The closely cemented structure of this mineral, even when finely powdered, makes it unsuited, in an economical sense, for direct application to soils. It must be previously converted into precipitated phosphate or su¬ perphosphate, for which purposes it is most eligible on account of its high content of lime phosphate and low proportion of waste con¬ stituents. THE RAW MATERIALS. 11 The commercial supply of apatite is limited, owing to the difficult accessibility of its sources. Phosphorite . The best qualities of this material are found at Estramadura in Spain, and Amberg in Bavaria. In both of these localities it abounds, but does not reach foreign markets in any quantity, because of the great expense of mining labour, and of the difficulties of inland transportation at the sources. It derives its name from its property of be¬ coming phosphorescent when heated. It is found in thick beds flanked with apa¬ tite and quartz. It is fibrous in structure, of a light yellow colour, and very hard, as well as difficult to powder. It is a very superior raw material for conversion into refined phos¬ phates ; and to this preparatory treatment it should be subjected in order to render it a prompt and economical fertilizer. Welsh Phosphorite . The phosphatic beds at Cwmgwnnen in the Lower Silurian series of North Wales has an 12 PURE FERTILIZERS. area, according to W. J. T. Dyer and A. H. Church, of four miles long by a width of eighty yards and a thickness of fifteen inches. It is worked by adit levels driven in from the hill side, which it intersects almost vertically. German Phosphorite. Recent geological surveys have revealed very extensive deposits of this mineral in the districts of Staffel, Limburg, Hinterland, Wetzlar, Oberlahn, Unterlahn, the borders of the river Lahn and Dill, and other portions of the right basin of the Rhine. “ It lies, generally, in diabase and shale overlapped or underlaid by lower and middle Devonian and by diluvial beds. The whole region is full of seams, beds and veins of black, red, and brown hematites.” On account of its immense mass, the mine¬ ral of the Staffel and Limburg beds can only be mined by blasting. It is an amorphous solid, of a brownish-yellow or fawn-grey colour, with a splintery fracture; but there are two varieties, one of which is friable and the other is soft. Though it contains some calcium fluoride THE RAW MATERIALS. 13 and carbonate, alumina, and oxide of iron, it is, nevertheless, a good raw material for re¬ fining purposes, and should be subjected to this preparatory treatment instead of being applied, in its natural powdered state, to the soil. The analysis, by Fresenius, in the table at page 30, represents a selected sample, doubt¬ less ; for that which forms a deposit of about four thousand German acres, near the Lahn river in Nassau, is several per cent, less rich. Its composition, according to Voelcker, is as follows :— Moisture - 0*3 6 Water of combination - 1*85 Phosphoric acid (= 3CaO, FO 5 65*19) - 29-86 Lime - 42*31 Magnesia - 0*30 Sulphuric acid - 0*65 Carbonic acid - 2'86 Oxide of iron - 4*43 Alumina and loss in analysis - - 6-33 Insoluble siliceous matter - 1 rc>5 IOO'OO Russian and A ustnan Phosphorite. The great phosphorite zone in Russia occupies an area of 20,000 square versts: 14 PURE FERTILIZERS. extending from the Volga, near Simbirsk, into the Desna district of Smolensk; and thence, after a real or apparent break, into the government of Grodno. Grewingk’s ana¬ lysis gives the following composition for the mineral:— Organic matter and constitutional water Moisture or accidental water Silica - Fluorid of calcium Proto-carbonate of iron Carbonate of magnesia Oxide of iron Alumina - Phosphate of alumina Tri-phosphate of lime Potassa - Soda - Sulphuric acid 4702 0910 42-965 3'535 3-847 I'6o2 0-922 5-027 1-874 32-950 0-751 0-593 0-076 99-754 Further southward, on the Zanks, on the Dniester, in Russian Podolia, and in the Bukowina, there are also deposits of phos¬ phorite, which Schwachofer describes as very rich on the average. The composition of the nodular portions resembles that of apatite. THE RAW MATERIALS. 15 Coprolites. True coprolites are not fossil excrements, as has been supposed, but worn and rounded fragments of fossil bones of a peculiar organ¬ ization. They are found in the green sand and crag of the lower chalk formation and adjoining strata. The false coprolites, as those of Suffolk, are a mixture of fossilized excrements, fish¬ bones, rolled stones, etc., forming beds in the more recent tertiary strata between the coral¬ line crag and the London clay. The coast of Suffolk and Cambridgeshire, England, are extensive localities for these phosphatic materials. They are also found abundantly in France and Germany, and to a small extent in Canada. Owing to the fluoride of calcium which they contain, hydrofluoric acid is evolved during the process of superphosphating them, and waste as well as discomfort ensue conse¬ quently. The presence of a large amount of carbonate of lime involves, also, a waste of acid ; to say nothing of the considerable pro¬ portion of alumina and oxide of iron, which not only are profligate constituents as regards PURE FERTILIZERS. 16 the consumption of the acid, but the means of rendering the “superphosphate’’ perma¬ nently damp. These circumstances, and the fact that their valueless constituents will di¬ lute the product to an extreme degree, reduce the coprolites to an inferior rank as a raw material, for the manufacture of refined phos¬ phate products. Nevertheless, they are em¬ ployed extensively for the purpose in Great Britain,—perhaps on account of their regular abundance and low price. They do not make “superphosphate” of good quality by the usual processes; nor are they so profitable for the methods of this treatise as even the “ South Carolina Phosphate”; and those in¬ ferior kinds of coprolites known as the “Wicken Coprolites” from Cambridgeshire and Bedfordshire; and “Calais Coprolites” from the Pas de Calais in France. Either of the two latter is to be obtained abundantly at a low price, and the following analyses will show their composition. The samples were obtained from a trustworthy source, and re¬ present fairly the average character of the respective deposits. They may be considered as typical members of the class of low grades of mineral phosphates of lime. THE RAW MATERIALS. 17 WICKEN COPROLITES. ( Morfit.) COPROLITES FROM PAS DE CALAIS. ( Morfit and B. IV. Gerland.) Moisture - - - 1 ‘66 Loss by ignition - 2*97 Silica, sand, & pyrites 24*46 Fluoride of calcium - 2*02 Sulphate of lime - 1*53 Carbonate of lime - 10*16 Lime (as silicate and organate) - - 6* 40 Tri-phosphate of lime. 35*66 Oxide of iron - 7*56 Alumina - - 4*07 Phosphoric acid 2*67 r T 4'3° Moisture o*6io Sand, pyrites, etc., in¬ soluble in PI Cl. ' - 33 ' 34 ° Silicic acid 1*490 Fluoride calcium 2*100 Sulphate of lime 2-487 Carbonate of lime - 1 1*360 Lime as silicate, etc. 7-360 Tri-phosphate lime 29-150 Tri-phosphate mag¬ nesia - - - 2-552 Oxides of iron, 2 , iii Alumina, 2*730 Phospho. acid, 5*700 99-16 100-990 A’ossa or Guaymas Guano. This is a very superior rock guano from Rossa Island, 28-3 north latitude, and 110-46 west longitude, near Guaymas, in the Gulf of California. It contains a portion of its phos¬ phate of lime in a di- or neutral state, and is almost wholly free from constituents which would waste acid. It is in hard lumps, but c 1 8 PURE FERTILIZERS. can be reduced to fine powder without diffi¬ culty ; and in this latter form is well suited for mixing with highly ammoniacal manures. For the purposes of this treatise, it may be considered almost a pure material, as the foreign matters are all excluded, by the action of the hydrochloric acid, in the very first stage of the refining processes. The analysis in the table represents a sample which I examined several years ago ; but, though the deposit is large, none has yet been brought into this market. Sombrero Guano . This is a rock guano constituting the entire structure of one of the Windward Islands in the Carribean Sea, called Sombrero. It is most probably a bone breccia ; as pieces of bone are found occasionally in the mass. It is not very hard, and forms a light yellow brown powder. I was the first to recognise the agricultural value of this mineral phosphate, and give it professional support when it was the object of great prejudice. The following analyses by Voelcker, of cargoes imported in 1871, show THE RAW MATERIALS . J 9 that notwithstanding a greater dampness, owing to being mined now below the level of the sea, it reaches the market in quality as good as that of the earlier importations which are represented by my figures in the analytical table at pages 30, 31. 1 2 3 4 5 6 7 8 Water and Organic > matters j 2-99 5-08 9*42 9-19 5-49 9-52 689 21 *20 Phosphoric ^ acid ) 32-32 30-84 30-98 30-84 32-86 30-48 3 1 ’ 16 27’82 Lime - Magnesia, 45*96 47-65 44-98 44-33 45-83 44 77 45-18 35-72 Ox. iron, f Carbonic ( II 21 15-48 13-53 I 4-59 H '57 14-14 I 5-45 14-56 acid, etc. J Sand & Silica 7-52 ’95 1 -19 i-o 5 1-25 1 -09 1.32 •70 IOO 'OO 100-00 IOO'OO IOO’OO IOO’OO 100 00 IOO’OO 100-00 There is one portion of the island which gives a mineral of the following composition, according to analysis by Evans and Jones ; but none of it has yet been mined for market. Moisture and water of combination - 6*01 Silica - icrio Carbonate of lime - - 4*43 Phosphate oflime - - 43*35 Phosphate of alumina - - 30’20 Alkaline salts - - 591 10000 C 2 20 PURE FERTILIZERS. St. Martin's Phosphate. This mineral is from the island of St. Martin’s, but has not been sent forward in any large quantity. The following analysis by Voelcker shows the composition of what may be considered an inferior sample. Water and loss on heating - 8 66 Carbonic acid - - II'S 7 Phosphoric acid - - - 2476 Lime - - - 45 4 i Alumina, ox. iron, and magnesia - 677 Insoluble silicates - 3*23 IOO'OO South Carolina Phosphate. This material comes from the neighbour¬ hood of the Ashley river, South Carolina, United States of America. It is in the form of hard nodules called Marlstones. The fish beds from which it is obtained are forty to fifty miles in extent. It maybe ground with¬ out difficulty, and forms a powder sometimes of an olive-grey shade, at others of a brown¬ ish-buff colour, and soluble in acids. Of all the mineral phosphates of lime which Revolving Sieve _ side and end elevation. TIIE RAW MATERIALS. 2 I arc available, in abundant and regular supply , these marlstones are among those best suited for the purpose of this treatise. Their ratio of carbonate and organate of lime is not un- profitably large where hydrochloric acid is cheap; and the solution of the iron and alumina constituents may be kept down in considerable degree by skilful manipulation. The remaining associates of the phosphate of lime constituent are merely valueless and not diluents or promoters of waste of acid. Their proportion of phosphate of lime, though only a moderate average, is thus really present in profitable degree. Another advantage is that the material may be bought at a comparatively lower price than minerals of the same class. The composition of that kind of “ South Carolina Phosphate” which gives a fawn- coloured powder, and as imported in 1870-1, is shown by the analytical table at pages 5 °> 31 • Another variety, whose powder is olive- greyish in colour, and now coming forward (1872) in greater or lesser quantity, has the following chemical constitution, according to 22 PURE FERTILIZERS . the full analysis of a sample from a recent cargo:— “SOUTH CAROLINA PHOSPHATE.” ( Morfit and B. IV. Gerland.) Moisture - - III Organic matter tm - 134 Insoluble, silica, sand, etc. - - 1156 Pyrites - - 1*24 Silica, dissolved by HC 1 . - - •86 Fluoride calcium - - 2-62 Sulphate lime «- 4*ii Carbonate lime - 14-02 Lime, as organate, silicate, aluminate 9*i 1 Tri-phosphate lime - - 42-13 Tri-phosphate magnesia - - 4*43 Oxide iron - I 83 s Alumina - - 2-0 7 l 8-39 Phosphoric acid 4*49 > IOO-92 A third variety of this phosphate is now being brought forward also, from Williman’s Island, Prince Williams parish, Beaufort County, S.C., formed by inlets on the eastern coast, about fifteen miles from the Atlantic Ocean. It comprises nearly 1600 acres, with a bed of phosphate running throughout, THE RAW MATERIALS. 23 which latter has been calculated to yield 10,000,000 tons. Dr. A. Voelcker, who examined this phos¬ phate, has reported that a careful and detailed analysis of the finely ground sample (un¬ washed) taken from the bulk at the Stores yielded the following results :— Moisture - - - -1*91 *Organic matter and water of combination 4/05 Phosphoric acid - 26*23 Magnesia - *24 Lime - 3978 Potash - ‘20 Soda - - - ‘63 Chloride of sodium - - ‘05 Sulphuric acid - 2*50 Oxide of iron - - 185 Alumina and a little fluorine - - 4^64 Insoluble silicious matter & soluble silica 1531 Carbonic acid - 2*60 10000 *Containing nitrogen Equal to ammonia •09 •11 “The presence of traces of nitrogenous or¬ ganic matter in this material appears to indi¬ cate its organic origin.” 24 PURE FERTILIZERS . “ Williman’s Island Guano resembles near¬ est in character the Cambridgeshire Copro- lites.” French Phosphate. This is most probably a species of bone breccia, for, though of rocky character, fossil bones are found with it in some of the open¬ ings. It extends over a wide area of the depart¬ ments of the Lot and Garonne, the Lot and the Aveyron in France, where it is found in detached veins and small pockets underlying the grey limestone on the highest plateaux of the mountains between the rivers Lot and Aveyron. The solid veins run generally from eastward to westward ; and the loose boulders are found embedded in a ferruginous looking clay and sand. It gives a light fawn coloured powder. The following analyses by Voelcker of several of the cargoes of 1871 show that it is a very high quality of mineral phos¬ phate. THE RAW MATERIALS . 25 Components. “Topaz.” “Denia.” “Maria.” “Rifle.” “Ar- mand Ma¬ rianne.” “ Philo- mene.” “ Hana- ton.” Water and loss 7 by heating ) 3-45 315 4-10 4*29 6-03 4*94 2*23 Phosphoric acid 36 07 36-64 33 *°5 34-89 33 - 8 o 34-90 37-60 Lime . 48-43 48 65 48 -46 47 09 48-25 49-62 46 52 Alumina and ' oxide of iron, magnesia, 9-56 9-04 12*40 II ‘02 9-24 8 89 13-04 carbonic acid, etc. Insoluble sili- cious matter J 2-49 2*52 1 ’99 2*71 268 1-65 •61 100*00 IOO OO 100 00 IOO 00 I OO'OO I OO'OO I OO’OO Navasa Guano or Coopcrite. The island which furnishes this mineral is on the coast of Hayti, in latitude 78 deg. 25 min. N., and longitude 75 deg. 2 min. W. As sent into the market by the proprietors, it is in brown lumps which give a powder like that of hematite. The very large proportion of iron and aluminium compounds, which it contains, distinguishes it from all other mineral phosphates of lime; and owing to this and other characteristic features I gave it, some years ago, the name of Cooperite, after the enterprising Captain of the Com¬ mercial Marine who first brought it into notice. 26 PURE FERTILIZERS . My analysis in the table at pages 30, 31 represents its composition at that time; and it is uncertain whether the quality has since improved. Those cargoes which arrive now are very variable in their degree of moisture; and there is also a want of uniformity in the quantitative relation of the phosphoric acid constituent. The annexed analyses represent the com¬ position of a superior and an inferior sample; so that the mean of the two may be accepted as the present average quality of the mineral. In my recent refining experiments on a large scale, I obtained from it about fifty-five per cent, of precipitated phosphate of lime in¬ dependent of the iron and alumina with which it was associated. The difficulty of prevent¬ ing the solution of a large portion of the oxide iron and alumina along with the phos¬ phate lime is the only objection to this raw material for superphosphating purposes, as it is cheap and in abundant supply. At the same time, the precipitated product which I obtained from it by my processes was of good quality and gave a “ superphosphate” THE RAW MATERIALS . 2/ much superior in every respect to that which any raw phosphate material, except bone-ash, could be made to yield. NAVASA GUANO OR COOPERITE. (Morfit and B. W. Gerland.) 1 2 Moisture - - 3-94 - 3 *i 3 Organic matter and loss by ignition - S '°7 - 5-32 Sand, silica, etc. mm - 4‘43 - 4‘37 Fluoride calcium - - U27 - 1-40 Sulphate lime - - i'og - I ‘2 I Lime, as organate, silicate, aluminate - 4-80 - I I * 12 Carbonate lime - - 4’63 - 652 Tri-phosphate lime m j 5 5'62 f 45 ' 5 2 Tri-phosphate magnesia - t 1 S3 Oxide iron - Alumina - > 19-86 - 22-24 Phosphoric acid - j 10071 99'86 Ovchila Guano. This material is best known in the United States market. It is brought from Orchila, an island in the Carribean Sea, lat. 11 deg, 50 min. N., and long. 66 deg. 14 min. W., and belonging to Venezuela. Its natural form is that of a rather damp, fawn-coloured 28 PURE " FERTILIZERS . powder. Its loose texture is advantageous for its direct application to the soil; but the pro- Note.— Charles P. Williams (Chemical News, xxiv, 306; and Journal of the Chemical Society , x, 269, 1872) has re¬ ported some very interesting results of a course of experi¬ ments upon the comparative solubility of several crude phosphates of lime. Care was observed to separate the dissolved phosphate of lime from any foreign associates in the liquor, so that its amount might be determined exactly. Molybdate of ammonia was the re-agent employed. Ac¬ cording to that Chemist:— One part of finely ground bone, containing 5678 per cent, of tri-phosphate of lime, dissolved in 5‘698 parts of water saturated with carbonic acid gas. One part of finely ground South Carolina Phosphate, con¬ taining 57*89 per cent, of tri-phosphate of lime, dis¬ solved in 6*983 parts of water saturated with carbonic acid gas. One part of finely ground Orchila Guano, containing 49*67 per cent, of tri-phosphate of lime, dissolved in 8*009 parts of water saturated with carbonic acid gas. One part of finely ground Bone-Ash, containing-per cent, of tri-phosphate of lime, dissolved in 8*029 parts of water saturated with carbonic acid gas. One part of levigated Apatite from Canada, containing 89*27 per cent, of tri-phosphate of lime, dissolved in 140*840 parts of water saturated with carbonic acid gas. One part of ground Apatite from Canada, containing 89*27 per cent, of tri-pnosphate of lime, dissolved in 222*222 parts of water saturated with carbonic acid gas. THE RAW MATERIALS. 2 9 portion of phosphate of lime which it contains renders its money value comparatively small. As this latter is associated with a very large amount of carbonate lime and other profligate components, the guano is not well suited for refining purposes. The analytical figures in the annexed table represent a sample which I obtained direct from the proprietor’s agent. The foregoing examples may be considered the commercial representatives of their class of materials ; for, with few exceptions, they are all now in the market. It is only the comparative expense of mining and trans¬ portation that makes any exceptional in¬ stances, and even those will disappear as soon as the contingencies of supply and de¬ mand may justify the bringing forward of present reserves. It is to be hoped, however, that in the meantime new and even cheaper sources, in rich abundance, may be found and developed; for, as phosphate of lime is the basis of crops, and bountiful harvests cheapen bread, which forms the staff of life, such incidents would erow as well a humanitarian influence in the o grandest and most practical sense. PURE FERTILIZERS . o o Analytical Table of the Comparative Crude Phosphates Rossa Gu- Apatite Apatite Phospho- Phospho- ano from from from rite from rite from Components. the Gulf of Canada. Norway. Spain. Germany. California. (Frese- (Morfit.) (T.S.Hunt.) (Voelcker.) (Ogston.) nius.) Bone or tri-phosphate ) lime and magnesia \ 53‘°8 91’20 90-74 8068 74^4 Neutral or diphosphate ) 18*03 lime - - - J Carbonate lime - — — — 4*26 3-43 Lime, with organic acids, silica, and > alumina - - ) — 4’59 1-83 i -34 Fluoride calcium — 7 - 6 o — •II 526 Chloride calcium — 78 1'61 — — Phosphate alumina - — — r66 — — Phosphate iron - — — — — Oxide aluminium 0’25 — traces 1 roS Oxide iron 0-15 — — ■ ‘ 5 o 6-42 Sulphate lime 8‘io — •— — — Potassa salts } *30 — — — 0-58 Soda salts - — — — 0-52 Organic matters 9 So — — — — Water, constitutional- f 3 62 Water, accidental — o -43 *20 2-45 Carbon - — — — — — Sand and silica - 6*20 0-90 r64 12-34 ob 99-53 100-48 100 67 99-93 100-55 THE RAW MATERIALS . 3i Composition of the Natural, of Lime. Bone-Ash from South America. (Morfit.) Bone-Black from Sugar Refineries. (Morfit.) Sombrero Guano. (Morfit.) True Coprolites, Cambridge. (Way.) False Coprolites, Suffolk. (Herepath). Marlstones or South Carolina Phosphate. (Morfit.) Cooperite or Navasa Guano. (Morfit.) Orchila Guano. (Morfit.) 703I 58-IO 67*06 57-09 5 5'49 52-21 46'80 45-84 IO '82 8-8o 5'34 I 3-27 I 3-40 1-92 1961 f 14*32 79 — 6-97 3 ‘ 4 i — ) 10-37 274 — — — 4'33 r 43 — — — — — — — i-66 — — • - — — 362 5*57 5*12 6-78 _ — i *95 178 i*6i 3"20 : 889 11-^6 — 3 'i 3 2 - 14 •80 11-62 •60 i — 1*10 traces traces / 37O — — •86 •80 70 — 1-02 — \ 1 t •61 •65 — — — t *20 •80 •49 f 1 ) — — — traces — 1 5*36 ) 8"oo 602 6-93 ' 8-6o — - 4‘°5 l 6-26 — — — ; 8-42 3'52 1 3-05 4'74 12-54 J 19-50 — — — — — — 9‘20 4-00 •68 6-93 12-45 13-96 4-50 1-24 100-34 99-80 ioo‘o8 99-98 9977 100-43 100 67 10026 32 PURE FERTILIZERS. Sulphuric Acid. S 0 3 . HO = 49. The composition of this acid in its pure state is as follows :— Dry sulphuric acid (S 0 3 ) - 40'00, or per cent. 81*63 Water of constitution (HO) 9*00 „ 18*37 Chemical equivalent - 49*00 „ 1 OO’OO The range and strength of affinities which pertain to this acid render it the most im¬ portant and useful chemical agent in the arts. There are very few salts of other acids which it will not decompose. Moreover, it is cheap and abundant. Sulphuric acid is met with in commerce of two strengths, the first being known as Oil of Vitriol having a specific gravity of 1*846, and the second, called Brown Oil of Vitriol , with a specific gravity of 1*700. This latter is the acid as it comes from the leaden chambers in which it is made. By subsequent concentra¬ tion in platinum or glass vessels it becomes Oil of Vitriol or Monohydrated Sulphuric Acid (S 0 3 HO). The brown or chamber acid has the formula S 0 3 HO + HO approximately. There are yet THE RAW MATERIALS. 33 weaker acids known in the factories but not met with in commerce and having respectively the specific gravity 1*450, 1*350, 1*250. Oil of vitriol is a transparent, colourless liquid of oily consistence which freezes at 29 deg. below o deg. F., and boils at 620 deg. F. It distils then without being decomposed, the fumes given off being those of dry sul¬ phuric acid (S 0 3 ). Sulphuric acid has a great affinity for water, and when one is added to the other so much heat is evolved that great care must be ob¬ served in mixing them. The dry acid (S 0 3 ) is not known in com¬ merce, and both the oil of vitriol and brown acid are solutions of dry acid in water, of dif¬ ferent strengths. The latter is much more economical than the former for manufacturing purposes, as all the expense of concentration is saved, strong acid not being required. There are thirteen carboys to the ton. In the manufacture of fertilizers, the con¬ sumption of sulphuric acid is so great that the cost of the carboys which contain it and the expense of transporting them are import¬ ant elements of consideration. It is advis- D 34 PURE FERTILIZERS. able, therefore, to manufacture the acid on the spot or else to locate the manure works in the immediate neighbourhood of a sulphuric acid factory. As differences of strength are due to degree of concentration, the weaker the acid the less expensive will be its use. One pound of oil of vitriol of specific gravity 1*846 is practically equivalent to :— 1*26 lbs. of brown sulphuric acid of sp. gravity, 1700 176 „ chamber „ „ 1*450 2 20 ,, „ „ ,, 1 '350 2 9 ^ ff » )> y> 1250 Every per cent, or pound of tri- or bone- phosphate of lime requires practically for its decomposition into soluble bi-phosphate of lime :— 0*64 lbs. of concentrated oil of vitriol of sp. gr., 1-846 0-82 „ brown „ „ 1 -700 1'14 » chamber sulphuric acid „ i’450 r 4 2 „ „ „ „ 1-350 r8 7 »» » „ „ 1*250 For the decomposition of each per cent, or pound of carbonate and organate of lime, there would be wasted / MORFll on the Manufacture of Fertilizers. \ E A Plate 3 Blakes Crusher _ Front Elevation 8c Plan. FIG. 3 CZ 3 CZ> o O o 0 o J o°o 0 n° n 0 „ 0 A c = o°o 0 o 0 0 0 r ° ° =>:o 0 o O o 0 o 0 o 0 o 0 o 0 o 0 o 0 o°o°o 0 o 0 o= 0 ° 0 ° G °°o 0 o 0 o 0 >; c ( r o " o0 ° °o 0 o°o 0 n 0 ° ° o O 0 o 0 o 0 o 0 o 0 o 0 o°o 0 o 0 ° ° ° ° o o°o :o 0 o 0 o 0 o 0 oW!° 0 o 0 o 0 o 0 o 0 o 0 o 0 o 0 o 0 I o0 ° 0o0 0 0 0 0 0 0 o C —.—, _ " — 3 CD cZ> r~:> , —. — ^ O • ° ° 0 CD o o / 4 - t 7 k SCALE l FEET a dally designed for D r Morfits Work’ aa fertilizers. Vincent Brooks. Day &.Soi\, Lath. Truhner & C°,6C, PaternosterRov THE RAW MATERIALS. 35 0*98 lbs. of concentrated oil of vitriol of sp. gr., r846 126 176 2-20 2-91 yy yy yy yy yy brown chamber sulphuric acid V ff yy ff yy yy yy 1700 1-450 I ' 35 ° 1 250 Urcs Table of the Quantity of Concentrated (SO HO) and Dry Sulphuric Acid (SO) in 100 parts of Dilute Acid at different densities. Specific Gravity. Liquid Acid in 100 . Dry Acid in 100 . Specific Gravity. Liquid Acid in 100 . Dry Acid in 100 . Specific Gravity. Liquid Acid in 100 . Dry Acid in IOO. I ’8460 100 81*54 1 ’55°3 66 53-82 1 ‘2334 32 26-09 I ’8438 99 80-72 I 5390 65 53*0° 1 -2260 31 25-28 1-8415 98 79-90 1-5280 64 52-18 1-2184 30 24-46 i ’8391. 97 79 09 i'5 I 7° 63 5i*37 1 *2108 29 2365 I *8366 96 78-28 1 -5066 62 5o-55 I -2032 28 22-83 I -8340 95 77-46 1 -4960 61 49 74 1-1956 27 22 OI I-8288 94 76-45 1 -4860 60 48 92 1-1876 26 21 ’20 I '8235 93 75 83 1 -4760 59 48-11 I -1792 25 20-38 i -8181 92 75 02 1 -4660 58 47-29 I -1706 24 I9-57 1 -8026 91 74-20 1 -4560 57 46:48 I -1626 23 18-75 1 -8070 90 73'39 1 -4460 56 45 "66 1-1549 22 17-94 1 -7986 89 72-57 1-4360 55 44'85 1-1480 21 I7-I2 1 -7901 88 7i75 1 -4265 54 44*03 I -1410 20 16-31 1-7815 87 70-94 1 -4170 53 43-22 1-1330 19 15-49 1 7728 86 7012 1 -4073 52 42 -40 I -1246 18 14-68 1 -7640 85 69-31 1-3977 5i 41-58 1-1165 17 1.3-86 1 7540 84 68-49 1-3884 50 40-77 I • 1090 16 l'3-05 i75 2 5 83 67-68 1-3788 49 39-96 i '1019 15 12-23 1 * 73*5 82 66-86 1-3697 48 3914 1 *0951 u II- 4 I 1 -7200 81 66*05 1 -3612 47 3872 1 -0887 13 io’6o 1 -7080 80 65 23 i-353o 46 377I 1 0809 12 9-78 1 -6972 79 64-42 1 '3440 45 36-69 1 -0743 11 8 97 1 - 686 o 78 63 60 1-33+5 44 35-88 1 0682 10 815 1 6744 77 6278 1-3255 43 35-o6 1 -0614 9 7-34 1 -6624 76 61-97 1 *3 l6 5 42 34-25 1 -0544 8 6-52 1 -6500 75 61-15 r -3080 4i 33-43 1-0477 7 57i 1-6415 74 60 34 1 -2999 40 3261 1-0405 6 4 89 1 6321 73 59-52 1-2913 39 31-80 1 0336 5 4-08 1 -6204 72 58-71 1 -2826 38 30-98 1 -0268 4 326 1 6090 7 1 57 89 1 -2740 37 30-17 1 0206 3 2-44 1 5975 70 57 ‘o 8 1-2654 36 2935 1*0140 2 1-63 1 -5868 69 56-26 1-2572 35 28-54 1 0074 1 081 1-5760 68 55'45 1 -2490 34 27-72 1 -5648 67 54 6 3 1 -2409 33 26-91 _ | D 2 36 PURE FERTILIZERS . Hydrochloric Acid. H C 1 = 36 * 5. In a pure gaseous state, it has the following composition :— Chlorine (Cl) - - 35‘5, or per cent. - 97*26 Hydrogen (H) - -1*0 „ - 2*74 Chemical equivalent - 36*5 „ - ioo*oo Hydrochloric acid is rarely found free except in certain mineral waters and volcanic exhalations. It is diffused, however, in nature to a wide extent, as chloride of sodium and other chlorides or hydrochlo¬ rates. Commercial hydrochloric acid is a solution of dry acid in water, and as made, direct, from chloride of sodium, it has the specific gravity 1*170 to 1*247. That which is found in com¬ merce, however, rarely has a greater strength than specific gravity 1*170. This latter is, in Great Britain and France, a by-product of the soda manufacture obtained by condensing the vapours, from the decomposing furnaces, in Gossages coke towers ; and may be bought there to any extent at 12 to 15 shillings per ton. THE RAW MATERIALS . 37 A factory for fertilizers should form a part of every soda-works, in order that the large incidental product of hydrochloric acid may be utilized advantageously on the spot. Chemically considered, one equivalent of dry or gaseous hydrochloric acid (HC1=36*5) is equivalent to one equivalent of dry sul¬ phuric acid (SO 3 = 40). Therefore, as the commercial hydrochloric acid of specific gravity 1*170 contains 34*25 per cent, of gaseous acid (HC 1 ), one pound of it is equiva¬ lent to 0*46 pounds of concentrated oil of vitriol of specific gravity 1*846 or 0*58 pounds of brown oil of vitriol of specific gravity 1*700. For the same reason, every 1*0 carbonate of lime would require for its decomposition 2*13 of hydrochloric acid (1*170) and form i*ii of dry chloride calcium (CaCl). So also, every 1*0 of tri-phosphate lime needs for its solution 1*37 of this hydro¬ chloric acid; and there is produced 071 of dry chloride calcium (CaCl). As hydrochloric acid, whether weak or strong, always gives off fumes, at even or¬ dinary temperatures, it is necessary to be careful in manipulating with it. The reser- 38 PURE FERTILIZERS. voir which is to hold it and the pipes which are to convey it must be closed, consequently, and lined with stearic pitch, gutta-percha, or caoutchouc. Ures Table showing the per cent, of Gaseous or Dry Acids in Hydrochloric Acid of different densities at 62° F. Specific Gravity. Gaseous Acid (HC1). Specific Gravity. Gaseous Acid (HC1). Specific Gravity. Gaseous Acid (HC1). Specific Gravity. Gaseous Acid (HC1) 1-2000 40-777 i-i575 30-582 I-IOOO 20-388 1*0497 IO-I94 1*1982 40-369 1-1494 30-174 1-0980 19-980 1-0477 9-786 1*1964 39-961 i-i473 29*767 1-0960 19-572 1-0457 9-379 I * 1946 39-554 1-1452 29-359 1-0939 19-165 1-0437 8-971 IT928 39-146 1-1431 28-951 1*0919 18-757 1-0417 8-563 I-I 9 IO 38738 1-1410 28-544 1-0899 18-349 1-0397 8-155 1-1893 38-330 1*1389 28-136 1-0879 17-941 1-0377 7-747 I-I875 37-923 1-1369 27-728 1-0859 I7-534 1-0357 7-340 I-I857 37716 I-I349 27-321 1-0838 17-126 1-0337 6-932 1*1846 37-108 1-1328 26-913 1-0813 16-718 1-0318 6524 I-l822 36-700 1-1308 26-505 1-0798 16*310 1-0298 6116 1-1802 36*292 1-1287 26*098 1-0778 15-902 1-0279 5-709 1-1782 35-884 1-1267 25-690 1-0758 I5’494 1-0259 5'3oi 1-1762 35-476 1-1247 25-282 1*0738 15-087 1-0239 4-895 1*1741 35-068 1-1226 24-874 1-0718 14-679 1-0220 4.486 1-1721 34-660 i-1206 24-466 1-0697 14-271 I -02IO 4-078 1-1701 34-252 1-1185 24-058 1*0677 13-683 roiSo 3*670 i-i68i 33-845 1-1164 23-650 1-0657 I3'456 1*0160 3-262 1-1661 33*457 i'ii43 23*242 1-0637 13-049 1-0140 2-854 1-1641 33-029 i-i 123 22-834 1-0617 12-641 I "0120 2*447 1*1620 32*621 1 • 1102 22-426 I‘0597 12-233 i-oioo 2-039 I-I599 32-2I3 1-1082 22-019 1-0577 11-825 I *0080 1-631 1-1578 31-805 1-1061 2 I- 6 i 1 I "°557 11-418 I *0060 1-124 rI 557 31’398 1-1041 2 I -203 i-o537 IIOIO I '0040 0-816 1*1537 30-990 1 -1020 20-796 1-0517 10*602 I -0020 0-408 THE RAW MATERIALS. 39 Crude Ammonia Liquor. The most common form of this material is “gas liquor \ one of the products incident to the destructive distillation of bituminous coal in the manufacture of illuminating gas. It is formed also, and largely, as a secondary product, in the manufacture of animal char¬ coal from bones, and in the destructive distillation of bituminous schists, refuse oil¬ cake, woollen waste, leather clippings, and nitrogenous, organic matters generally. Theoretically, every 14 per cent, of nitro¬ gen in the raw material should give 17 per cent, of ammonia; but, owing to various difficulties and complexities in the mechani¬ cal, as well as chemical, circumstances of the practical conversion, the actual results do not approach this estimate. When the raw material contains sulphur, as in the case of coal, then the liquor distilled from it will hold the ammonia, principally as carbonate, but associated with sulphide, sul¬ phate, chloride, and ferrocyanide. As ob¬ tained from other sources, it is almost wholly a solution of carbonate of ammonia. 40 PURE FERTILIZERS. The coal-gas liquor, which is in fact a solution of crude ammonium salts, comes over with tar, and is condensed in the hydraulic main ; but the tar forms a separate stratum, and the two may be separated readily by decantation or drawing off from the containing cistern or well. The volume of tar is greater, generally, by 20 per cent, than that of the ammonia liquor. In the manufacture of gas from coal, as much as 60 per cent, of the ammonia, it is said, remains with the gas ; but, according to Wright, one ton of good Newcastle coal will yield, nevertheless, ten gallons of liquor weighing 100 pounds. Pockston names 11 to 13 imperial gallons as the usual product from a ton of good coal. Clegg states that the amount of ammo- niacal product varies with the temperature at which the destructive distillation of the coal is effected. Very high heat diminishes the product by converting a portion of the am¬ monia into cyanogen. Nevertheless, the usual amount of liquor obtained from one ton of Newcastle coal is ten imperial gallons, equivalent to 3-3J ounces of dry caustic am- THE RAW MATERIALS. 4i monia, or a total of 30 to 32J ounces. In addition, the gas retains so much more as to raise the actual yield of dry ammonia gas from one ton of Newcastle coal to six pounds avoirdupois. The liquor from boghead and cannel coals yields less ammonia, generally, than that from the bituminous coals. Berger Spence and Peter Dunn (chapter xix) propose to abstract all the ammonia re¬ tained in the gas by passing it through the crude phosphoric acid liquor obtained in the chemical treatment of mineral phosphates of alumina (chapter xix). The gas would be thus purified by the formation, simultane¬ ously, of phosphate ammonia—a very valu¬ able product. To make caustic ammonia from gas-liquor, it is only necessary to add lime (with some chloride of iron) to the latter in the propor¬ tion of five per cent, of its weight, and then to distil. The gaseous distillate passing over is to be received in water, which at 50° F. condenses 670 to 780 times its volume of am- moniacal gas. The strength of crude ammoniacal liquor varies with its source. It is sold usually by 4 ^ PURE FERTILIZERS . the ton at one shilling for every degree it may show by Twaddel s hydrometer, and each degree of this instrument represents 0*47 dry ammonia gas. Owing to the liquor being a mixture of several different ammonium salts, this mode of estimating the strength is very rough. A better, but yet only approximately correct method, would be to take a weighed measure of the liquor, neutralize it with pure hydro¬ chloric acid, evaporate it to dryness, and weigh the residue. In this manner I ob¬ tained two and three quarter ounces of solid chloride of ammonium from 16 fluid ounces of the liquor of a private gas-works. Assays of liquor from other works showed, in like manner, an average of nine per cent, of chlo¬ ride, or, say three per cent, of dry caustic ammonia. According to Knapp, one imperial gallon, or, say ten pounds, of gas-liquor yield, by distillation to hydrochloric acid, 31 to 39 ounces of solid chloride of ammonium, equi¬ valent to an average of 17*50 per cent. Barreswill, an eminent French chemist, states that 2000 litres of gas-liquor give 100 THE RAW MATERIALS . 43 kilogrammes of sulphate of ammonia, or in the proportion of 5 per cent, of the weight, which is equal to ij per cent, of dry caustic ammonia. English manufacturers of fertilizers report to me that 1000 gallons of gas-liquor, weigh¬ ing, say, io'ooo pounds, produce an average of ten hundredweight of sulphate of ammo¬ nia; that is, about 10 per cent., equivalent to 2*50 per cent, of dry caustic ammonia. The average strength of English gas- liquor, therefore, to be deduced from these data, is, in round numbers, 3 per cent, of dry caustic ammonia, or sixty pounds and up¬ wards per ton. Some idea of the extent to which this liquor is produced may be obtained by con¬ sidering the fact that the amount of coal con¬ sumed for gas in London alone, is nearly one and a half millions of tons yearly. And, as every city, town, hamlet, railway station, factory, and large farm establishment, will, sooner or later, have its gas-works, this source of ammonia-supply will become even richer than at present. In addition, however, to gas-liquor, there 44 PURE FERTILIZERS. are other abundant sources of ammonia, and notably the manufacture of bone-black from bones, in which it also distils over as a crude liquor. According to Kamrodt, the nitrogen is as follows, in the various waste products of commerce:— Horn - 15 to 17 per cent. Feathers - 17 a Bristles - 9 to 10 yy Hide cuttings - 4*5 to 5 yy Old shoes 6 to 7 yy Good woollen rags - 13 to 16 yy Inferior woollen rags - 10 to 12 yy Ox, cow, and calves’ hair - 15 to 17 yj Dried ox blood - 15 to 17 yy Sheep’s wool - 16 to 17 yy Shoddy - - 7 to 9 yy Wool. The destructive distillation of wool is an¬ other source of ammonia. Wool, when fresh, contains, according to Scherer, 13 to 16 per cent, of water. On exposure to air, 6 to 7 per cent, of this water passes away by evapo¬ ration ; and the wool, thus dried, yields by calcination, 3-23 of ash. The ultimate com¬ position of wool is— THE RAW MATERIALS. 45 Carbon - 50'65 Hydrogen 7*03 Nitrogen - - 1771 Oxygen, sulphur, etc. 24-61 I OCT OO The following table of the present supply and market values of the several kinds of woollen waste in England, is made from data furnished to me by Mr. W. G. Etchelss, Huddersfield :— Kind of Woollen Waste. I. Willy dust 3 * » 4. Cutters’ flocks - 5. Shoddy - - 18s. to 6. New woollen rags or cut -} tings 3 7. Old woollen rags or cut- ) tings 3 Present Market Price in England per ton. Probable amount of Supply annually in Great Britain. £ s. d. OIOO 10,000 tons O O 0 — 0 0 hH O — O O 1,000 tons I O 0 10,000 „ 10 and ) upwards 3 Any quantity 4 and ) upwards 3 Any quantity Leather Clippings. The almost unlimited supply of this waste material, which abounds everywhere, and 46 PURE FERTILIZERS. may be collected at a nominal cost, renders it a very suitable basis for an ammonia process by destructive distillation. The quantity of nitrogen which it contains is always large, but varies more or less with the kind of leather waste. Dried Blood . In the extensive slaughter-houses of the United States of America, as well as in the abattoirs of France, the blood of the animals which are killed for food is either dried or solidified by coagulation, and thus econo¬ mised for market. Its condensed form and richness in nitrogen render it a most valu¬ able nitrogenous material for fertilizing pur¬ poses or the production of ammoniacal salts. Dried Flesh. In countries where cattle, sheep, and hogs abound and are killed for their hides and tallow and the flesh is boiled for extract of meat, there is a fibrinous residue which, when dried, becomes a most advantageous nitrogenous material for all the purposes of this treatise. The supply of it is very large. THE RAW MATERIALS. 47 Human Excrements. This source alone, if properly utilized, would supply the larger part of all the am¬ monia salts that are required by mankind. The dejecta of each person amount per day to 4J- lbs. ; and these dejecta, comprising 3 lbs. of urine and 20 oz. of solid faeces, contain the average of 150 grains of nitro¬ gen, which is equivalent, in that element, to 6000 grains or nearly a pound of wheat flour. Two hundred pounds of wheat flour are con¬ sidered a liberal annual apportionment to each person. All this wealth of fertilizing matter might be economised by such a municipal regulation as would compel the inhabitants of towns or cities to construct their privies with box-recep¬ tacles and a automatic, hopper arrangement, by which the dejecta would become mixed with dry earth as they fell. The deodorizing and absorbent properties of the dry earth would render the mixture easy to be handled and removed for further drying in heated air- currents. Thus prepared and powdered, it would then be ready for combustion with 48 PURE FERTILIZERS. soda lime, according to the methods sug¬ gested at p. 53. In this manner, all the contained nitrogen would be eliminated as ammonia distillate, to be condensed into ammoniacal salt by means of sulphuric, hydrochloric, or crude phos¬ phoric acid. The solid residuum or calx would consist of sand, soda, and carbonate of lime, together with phosphate of lime or phosphate of soda. If the latter is present, it will have been formed from the phosphate of lime element of the faeces, by interaction with the soda under the fluxing influence of the high heat employed for the combustion. Indeed, the chemical and mechanical conditions of the combustion might be arranged so as to insure the total conversion of the phosphate of lime into phosphate of soda. The solid residue would then yield this latter as an aqueous solution by simple leeching with water. The phosphate of soda thus isolated, is a most valuable liquor for economising the wash or mother liquor in chapter xi. By merely mixing the two, an exchange of bases would take place, and pure phosphate of lime would THE RAW MATERIALS. 49 precipitate, leaving chloride of sodium or common salt in solution. On the other hand, if the combustion should be managed so as to preserve intact the phosphate of lime element, then the soda may be washed out by means of water and evaporated to dryness for repeated use an in¬ definite number of times. The remainder of the solid residuum is in itself a valuable mineral manure, or it may be dried, powdered, and substituted advan¬ tageously, for earth, as the drying and de¬ odorizing material to be used in the privies. Sewage. Several of the processes now in use for the defecation of town sewage render the latter a valuable source of ammonia. The precipitate thus produced carries down the suspended organic matter of the sewage ; and this latter may be then isolated by merely dissolving the earthy portion of the precipitate in hydrochlo¬ ric or sulphuric acid. The organic matter, on being dried carefully, is a most potential form of nitrogen, for direct use as a fertilizing agent, as it contains the equivalent of about 7 per 50 PURE FERTILIZERS . cent, of ammonia, associated with valuable humus matters. It forms, also, a most con¬ centrated material for combustion with soda- lime, to produce ammonia salts by Morris and Penny’s process, described at p. 53; provided always that it is wholly or nearly free from sand and silica. At the same time, the decanted liquor being a hydrochloric or sulphuric solution of the de¬ fecating elements of the original material, is ready for purifying a fresh portion of sewage, as in the first instance; and thus it may be made to serve for an indefinite number of repetitions of the process. The establishment, in this manner, of an independence of any possible failure in the supply of the Alta Vela, Redonda, or other of the mineral phosphate materials employed in the purification of sewage, is an important consideration, and invests the process with a capacity for emi¬ nent utility and economy. The ammoniacal salts are such necessary aids to profitable agriculture, that every means should be promoted to increase the supply of them. As a stimulus to enterprise in this direction, I have exposed the fore- ENTR ORFTI on ike Manufacture okFciiilizers. FIG. I FIG. 2 FI G. 3 FIG. 4 . 7 FIG SCALE OF FEET FIG. C k I — I J d ~ I—1 '~~ I — 1 I— — i ± Plate 4. Centrifugal Mill_General View & Details aediar i>. MarnCs Work or Fertilizer Vincent Brooks, Lav&San, Lith. runner ,b0 Paternoster 3 THE RAW MATERIALS. 5i going details, and set forth in Chapter xi a simple and practicable process for reclaiming the ammonia of gas-liquor wherever the latter may be found. The comparative abundance and cheapness of the several kinds of woollen and leather waste deserve the most serious consideration in this connection. I have long given the subject such study as my leisure would per¬ mit, and the plan for converting these ma¬ terials into ammonia, which would be most likely to succeed, is one assimilating in cha¬ racter to the analytical method of estimating the amount of nitrogen in organic bodies by combustion with soda-lime. The principle upon which such a process would be founded is safe and well-established, and consists in the property which nitro¬ genous organic bodies have of giving off the whole of their nitrogen in the form of ammonia, when strongly heated with hydrated alkalies. The soda-lime employed may be reclaimed an indefinite number of times ; so that the expense on this item would be at the lowest possible point. But there are mechanical difficulties which beset the necessary arrange- 52 PURE FERTILIZERS. ment for effecting a progressive combustion on a large scale. My present idea is to use iron retorts, like those for making coal-gas, but longer, and with suitable valve-cocks for safety, and tube-attachments to convey away the gas and intercept the fluid portion of the distillate. The mixture of waste and soda-lime having been put into a series of retorts, the whole are to be closed and made air-tight at the joints by means of fire-lute. As it would cause a too sudden and free flow of distillate to put fire under the retort throughout its entire length at once, the heating would have to be restricted at the commencement to the first twelve inches of the front or mouth por¬ tion of the retort, and pushed forward gradu¬ ally as the current of gas from the preceding part begins to slacken. It is necessary that a good fire should en¬ velope the top of the retort as well as the bottom. Indeed, it is the arrangement of the heating appliances, so as to produce a pro¬ gressive and perfect combustion of a large quantity of waste in each retort, that presents the chief obstacle to the installation of an THE RAW MATERIALS. 53 economical and ready-working process upon the basis which I have suggested. As the obstacle is not by any means insurmountable, I hope that it may soon have solution by some competent mind and hand. Richard Morris and Mulgrave Daniel Penny, manufacturing chemists of Yorkshire, England, obtained a patent recently for a process in this direction, which they describe as follows:— “The process is for treating shoddy and other animal waste to obtain ammonia and salts of ammonia therefrom. “We decompose the shoddy, or it may be leather cuttings, horn piths, or such-like animal waste, in clay or iron retorts, heated to a cherry red ; and we admit jets of steam into the retorts. Retorts like those used for the manufacture of coal-gas, and similarly set in a furnace may be employed. “The gases and vapours from these retorts are passed into a main, as in the manufacture of coal-gas, where tar and ammoniacal water are deposited. From the main, the gases and vapours pass into the retorts containing the alkaline matter. “ Lime is the material we commonly em¬ ploy. The lime retorts are similar, but of 54 PURE FERTILIZERS. greater length, say twenty feet or thereabout. They are heated to a white-heat. The gases and vapours are passed in succession through the lime retorts (six retorts are a convenient number to employ), and then they are caused to enter an absorbing tower where the am¬ monia formed is absorbed by acid, by prefer¬ ence sulphuric acid. The water and the tar which condense in the main, and the acid in the absorbing vessel, contain all the ammonia. “The acid is drawn off from the absorbing vessel from time to time, and saturated by distilling ammonia into it from the water of the main. Finally, the saturated solution is evaporated to the point of crystallization. “The gas, of which the quantity is large, is collected in gasometers, and it may be em¬ ployed for the purposes of heating and light¬ ing. An exhauster may advantageously be employed to draw the gas and vapour from the retorts, as is usual in the manufacture of gas. The shoddy, or animal-matter retorts, are re-charged in succession, as soon as it is found that the material in them is spent, and the residue is useful as animal charcoal or as manure. The lime retorts are also re-charged from time to time, whenever the lime is found to have become clogged with deposit and spent; the gas and vapour are caused to pass THE RAW MATERIALS. 55 first into the lime retort which has been longest charged, and last into that which has been most recently replenished. Sometimes we charge the last retort of the series with soda-lime or with caustic soda, in place of with lime, and so get a most perfect conver¬ sion of the nitrogen of the animal matter into ammonia. We purify the sulphate and other salt of ammonia by crystallization in the usual way, and from this ammonia salt caustic ammonia may be obtained by heating with lime, as is well understood.” Sulphate of Ammonia. NH 3 , S 0 3 , HO =66. This salt, when pure, is composed of— Ammonia (NH 3 ) - - 17*0, or per cent., 2575 Sulphuric acid (S 0 3 ) - - 40'0 „ 6o'62 Water of constitution (HO) - 9*0 „ 1 3*^3 Chemical equivalent - - 66*o „ iocroo This is the neutral sulphate obtained on a large scale from the water of condensation, produced in the distillation of coal for gener¬ ating illuminating gas, and in the calcina¬ tion of bones for making bone-black or bone- ash. It is manufactured, also, from stale urine and other animal matters. It is in 56 PURE FERTILIZERS. crystals, which are colourless when pure, but dirty grey or brownish when crude. The crystals are six-sided prisms, with correspond¬ ing pyramidal tops, and have a specific gravity of 175. They are very soluble in cold water, but insoluble in alcohol, and have a bitter, piquant taste. Sulphate of ammonia melts at 284° F., but resists decomposition up to 356° F. Beyond the latter degree it loses ammonia, becomes firstly bi-sulphate, and changes finally into nitrogen, water, and bi-sulphate of ammonia, which sublimes. This salt is the means by which I change the chloride of calcium of hydrochloric solu¬ tions of mineral phosphates of lime, into chloride of ammonia and sulphate of lime ; so as to reclaim the hydrochloric acid profit¬ ably, and, at the same time, to free the preci¬ pitated phosphate of lime from any hygro¬ scopic or humid tendency. Each (ro) per cent, or pound of this neu¬ tral sulphate of ammonia is equivalent to 1-32 neutral sulphate of potassa. For each pound (ro) of carbonate or or- ganate of lime that may have been dissolved THE RAW MATERIALS . 57 out of the mineral phosphate by hydrochloric acid (2*13), there will be required 1*32 pounds of sulphate of ammonia, and the products would be— 172 lbs. of hydrated sulph. of lime (CaO, S 0 3 , 2HO) ; 1*07 lbs. of dry chloride of ammonium (NH 3 , HC1). Chloride of Ammonium, or Hydrochlorate of Ammonia. NH 3 , HC1=53'5- When pure, its composition is— Ammonia (NH*) - - iyo, or per cent, 3178 Hydrochloric acid (HC 1 ) 363 „ 68 22 Chemical equivalent - 5 3 ’ 5 » IOO'OO This salt crystallizes in needles, which are soluble in water and alcohol. It is always anhydrous, and sublimes unaltered at a tem¬ perature just below redness. It is commonly called Sal Ammoniac. Specific gravity, 1-45 to 1 '50. Its per cent, of ammonia is much higher than that of the sulphate (2575), and on this account, as well as for other good reasons, it is to be preferred for fertilizing purposes. 53 PURE FERTILIZERS . Sulphate of Potassa. KO, S 0 3 = 87 ‘o. Its composition, when pure, is as follows : - Potassa (KO) - - - 47*00, or per cent., 54*00 Sulphuric acid (SO 3 ) - 40*00 ,, 46*00 Chemical equivalent - 87*00 „ 100*00 This is a neutral salt in the form of colour¬ less hard crystals, which are very soluble in cold or hot water, and resist decomposition at even high temperatures. Its specific gravity in the anhydrous state is 2’625 ; but it varies from 2’623 to 2‘656 in the ordinary com¬ mercial article. It is used alone or in conjunction with sulphate of ammonia for economising the chlo¬ ride of calcium wash liquor in the processes of this treatise, by precipitating the lime as sulphate and forming chloride of potassium. But it is in no sense as advantageous for that purpose as the sulphate of ammonia. Each per cent, (ro) or pound of carbonate and organate of lime which has been decom¬ posed and dissolved by hydrochloric acid (2*13) from the raw mineral, requires 174 THE RAW MATERIALS . 59 pounds of this neutral sulphate of potassa, and forms— 1*72 lbs. of hydrated sulph.of lime (CaO, S 0 3 , 2HO) ; 1*49 lbs. of dry chloride of potassium (KC 1 ). This salt is a secondary or reclaimed product in the clarification of oils and in many other manufacturing processes. Dark coloured crystals cost less than the bright, and are sufficiently pure for this process. It is also sent to market largely from the natural deposits at Stassfurt, in Prussia, and in this form is known commercially as kainit; which contains, as an average, 23 to 25 per cent, of sulphate of potassa, associated with 14 to 28 per cent, of magnesia salts and 30 to 48 per cent, of chloride of sodium. Chloride of Potassium . KC 1 = 74 ’ 5 . Its composition is— Potassium (K) - 39-0, or percent, 52 , 35=KO, 63*1 Chlorine (Cl) - 35-5 „ 47^5 Chemical equiv. - 743 ,, IOO'OO This is an anhydrous salt which crystallizes in cubes or rectangular prisms, and dissolves 6o pur it fertilizers. in about two and a half times its weight of cold water. It volatilizes at a red heat with¬ out decomposing. Specific gravity i'95o. Carbonate of Potassa. KO, C0 2 =69’o. When pure and ignited its composition is : Potassa (KO) - - 47*00, or per cent., 68* n Carbonic acid - - 22*oo „ 31*89 Chemical equivalent - 69*00 „ 100*00 As found in commerce, however, it is a more or less impure salt under the names of salt of tartar and pearl ash , and contains about 16 per cent, of water of crystallization. The first is in the form of a coarse granu¬ lated powder, insoluble in alcohol, but very soluble in water and even deliquescent. It fuses at a red heat without decomposing. Salt of tartar is refined pearl-ash, obtained by dissolving the latter in water, and leaving it to repose. The clear liquor contains all the caustic and carbonate of potassa, with some portion of the other soluble salts of the pearl- ash, and rests upon a sediment of insoluble impurities. The liquor being then drawn off and concentrated by evaporation, drops a fur- THE RAW MATERIALS. 61 ther portion of its foreign salts, from which it must be decanted. Thus largely freed from impurities it is finally evaporated to syrup and stirred into dry granular salt of tartar. It is employed in the processes which will be described for the mineral phosphates of alumina ; and would answer the required pur¬ poses in its crude form of pearlash. Lime. CaO=28. The composition of caustic lime when pure is— Calcium (Ca) - - 20*0, or per cent, 71*42 Oxygen (O) - 8*o „ 28*58 Chemical equivalent - 28*0 „ 100*00 It is largely diffused in nature as carbonate and sulphate, and forms the basis of lime¬ stones, chalk, the various kinds of marbles, calcareous spars, gypsum and many other minerals. Caustic lime is obtained by calcining lime¬ stone or other carbonate of lime in suitable kilns. In this way the carbonic acid is driven off and lime remains in a “quick” or caustic state mixed with more or less of magnesia, 62 PURE FERTILIZERS . alumina, oxide of iron, silica, and the other impurities of the original raw material. These vary in quantity from 5 to 30 per cent, according to the kind of raw material ; and when the lime is to be employed in chemical equivalent proportion, the amount of foreign matters must be predetermined by analysis and excepted in the calculation. Any excess above five per cent, of impurities takes it out of the class of good lime for the processes of this treatise. Lime is in lumps, sometimes white and at others grey, very alkaline, and has such an affinity for water and carbonic acid that it must be kept in closed barrels protected from exposure to air. It is very soluble in acids, and forms salts with them. Hot water dis¬ solves it less readily and in less quantity than cold water, which latter takes it up in the proportion of one part of lime to every 730 parts of water. Specific gravity 2*3 to 3’o. When quick-lime is sprinkled to saturation with water it soon begins to give off hissing sounds, developes great heat and thick vapours of volatilized water, and finally en¬ larges its volume into a fine powder or THE RAW MATERIALS. 63 mass of slaked lime , which is a hydrate of lime=CaO, HO. In slaking the lime with half its weight of water, the temperature rises to 500°. The longer it takes to fall to powder after the drenching with water for slakening it, the more impure it is. A good rich lime is never longer than three to five minutes in answer¬ ing favourably to this test. If the quantity of water is then further in¬ creased so as to give a liquid character to the mixture, the product is milk of lime. This milk must be strained through a fine sieve of galvanized wire cloth. One equivalent of anhydrous lime(CaO=28) corresponds with one equivalent of dry hydro¬ chloric acid (HC1=36 , 5) or one equivalent of dry sulphuric acid (S 0 3 = 4 o). Carbonate of Lime. This substance is noted in another place as to its more scientific relations; so that it only remains to mention it here in its practical bearings upon the processes about to be described. The form employed is that commonly 6 4 PURE FERTILIZERS. known as whiting. It is prepared from cticilk, a white earthy mineral which may be considered, practically, as pure carbonate of lime. That is, its impurities are in small pro¬ portion, and mostly mechanical, and easily removed. It is the elimination of these latter which changes the chalk into whiting. According to Schweitzer s analysis, the chalk of Brighton (Sussex) cliff is composed of— Carbonate of lime - 98'5 7 Carbonate of magnesia - •38 Phosphate of lime •II Oxide of iron ‘OS Oxide of manganese *06 Alumina •l6 Silica - •64 100-00 The process consists in grinding the chalk, diffusing the powder in a large volume of water, and leaving to repose only so long as may be necessary for the subsidence of the heavy particles. The liquor, holding in sus¬ pension all of the finer portion, is to be drawn off into a vat and allowed to settle. When this has been accomplished, the supernatant water is to be drawn to waste through taps, ' -■ LIBRARV OF THt UNIVERSITY of lime 3 3CaO. P0 5 84‘O — 72-o( = 156) 53^5 — 46-15 (=100) Di- or Neu-1 tral - phos- > phateoflime ) 2CaO. P0 5 + HO 5 6- 9 72- ( = 137) 40-87 6-57 52-56( = ioo ) Bi - phosphate ^ of lime ) CaO. P0 5 + 2H0 28* 18 72 - (=Il8) 2373 15-26 61 -oi [— 100) Tri- or Bone-Phosphate of Lime. 3 CaO, po 5 =156. This is the most common form, being widely diffused in nature as the earthy CHEMICAL DATA. 69 structure of bones and the basis of mineral phosphates, such as apatite, phosphorite, coprolites, rock guanos, marlstones, and the like. It is also a component of ammoniacal guanos ; and the chief constituent of bone- black and bone-ashes. When associated with gelatine and other organic matters in its natural condition of ground bone, it breaks up in the soil under atmospheric influences into forms which are not only soluble but very assimilable by the growing crops. In the state of bone-black it is scarcely less soluble in the soil ; and in the form of bone- ash falls only a few degrees in rank of solu¬ bility below the bone-black. Weak acids dissolve it readily; and those of greater strength not only dissolve it but convert it into super-phosphate by abstracting two equivalents of its lime. In like manner, the presence of acetic acid, carbonic acid, chloride of ammonium, certain potassic salts, and chloride of sodium, causes it to split into more soluble phosphatic salts or states; and it is in this manner drawn up by growing crops into the vegetal circulation. 70 PURE FERTILIZERS . It may be prepared artificially from an aqueous solution of chloride of calcium by the addition of an aqueous solution of basic phosphate of soda ; or on a large scale by precipitating a hydrochloric acid solution of bone-phosphate of lime, or even of bone- ash, with pure ammonia. Strictly considered, however, this preci¬ pitate from the latter solutions is rather a mixture of several phosphates of lime, all quite prompt to assume solubility under the conditions existing in soils. When freshly precipitated from an acid solution, phosphate of lime is white and in¬ soluble in water, but peculiarly sensitive to the solvent action of water containing only a small quantity of ammonia or carbonic acid. This action, though gradual, is constant, and extends even to the precipitated phos¬ phate in a dry state. As existing in rock guanos or minerals, tri-phosphate of lime is not only cemented closely by associate ingredients, but has naturally a physical temperament which ren¬ ders it obstinate to the action of solvents CHEMICAL DATA. 7i under the ordinary conditions pertaining to the soil. These natural forms are conse¬ quently so very slow as fertilizers per se that chemical treatment must be practised to render them soluble previous to their applica¬ tion. This is particularly necessary when they are accompanied with fluoride of calcium, silicate of lime, alumina, phosphate of alu¬ mina, oxide and phosphate of iron. Di- or Neutral-Phosphate of Lime. 2 CaO, HO, PO s = 137. This phosphate exists in many mineral waters, but is rarely found in nature to any extent. The only two instances in my know¬ ledge are, that of the Colombian guano from Maracaibo, of which the stock has been ex¬ hausted long since ; and another rock-phos¬ phate from Rossa Island near Guaymas in the Gulf of California. It has been formed in nature, as it may be in the laboratory, by the gradual action of water, and particularly of water containing ammonia or alkali, upon bone-phosphate lime in a fresh state as exist¬ ing in bird dung or ammoniacal guanos. It 72 PURE FERTILIZERS . may be precipitated, too, from acid solutions ; and at the same time some bi-phosphate of lime is produced. As prepared artificially by adding an aque¬ ous solution of ordinary phosphate of soda to an aqueous solution of chloride of calcium, it is a white precipitate only slightly soluble in water, but very easily soluble in acids, and readily taken up by water containing carbonic acid, ammonia, ammoniacal or even potassic salts. Some little of it is formed in my process for manufacturing Colombian Phosphate , as described in Chapter ix; and the methods, described in Chapter x, produce it nearly pure. Guanos or artificial manures, which may contain their phosphatic element in the state of neutral phosphate of lime, will prove to be very active and potential fertilizers. Chemically considered, it is the best possi¬ ble material for conversion into “ superphos¬ phate”. The economy of sulphuric acid and the very high degree of soluble phosphate thus obtained will be great advantages to both producer and planter. CHEMICAL DATA . 73 Bi-phosphate of Lime. CaO, 2 HO, P 0 5 =i 18. This phosphate exists, naturally, only in small quantities, as a component of certain mineral waters and organic products. It is prepared artificially by acting on the tri-basic or bone phosphate of lime with di¬ lute sulphuric acid, which takes away two equivalents of lime, and, with two double equivalents of water, forms hydrated sulphate of lime; leaving the phosphoric acid with one equivalent of lime and two equivalents of water, as bi-phosphate. To make the decomposition perfectly intel¬ ligible, it is only necessary to formulate it as follows:— One equivalent of (CaO.2HO.PO5) Bi-phosphate of Lime. CaO. CaO. CaO. P0 5 ; 2SO3.2HO. 4HO. Two equivalents of ((2)Ca0.S03.2PI0.) Sulphate of lime. 74 PURE FERTILIZERS . The ascending lines represent the soluble product, and the descending lines indicate the insoluble one. As bone-phosphate of lime consists of three equivalents of lime (CaO, 28 x 3=84) and one equivalent of phosphoric acid (P, 32 4- O, 40= 72), it follows that every equivalent = 156 when acted on by oil of vitriol or mono- hydrated sulphuric acid diluted with four equivalents of water (2) S 0 3 HO (=98) + 4HO (=36)= 134, will yield— 1. Bi-phosphate of lime (CaO (28) 2HO (18) P 0 5 (72) = 118 parts by weight 2. Sulphate of lime (2) CaO (56) 4HO (36) 2SO3 (80) = 172 parts by weight As much heat is generated during the chemical reaction, an excess of water must be added to provide for loss by evaporation. Taking this circumstance into consideration, then, by adding together the original items of the formula, the proof of the latter is made evident, thus :— One equivalent of bone-phosphate of lime= 156 by weight. Two equiv. of mono-hydrated sulphuric acid = 98 „ Two double equivalents of water of dilution^ 36 „ Total 290 CHEMICAL DATA. 75 Converted into— One equivalent of bi-phosphate of lime = 118 by weight. Two equivalents of sulphate of lime = 172 „ Total - - 290 This salt is very soluble in water, and its aqueous solution when evaporated to syrupy consistence crystallizes in pearly scales, which are deliquescent. These scales, if heated too long, even moderately, assume in part an allo- tropic condition, which is somewhat insoluble. By igneous fusion it wholly loses its property of solubility. Of all the phosphates of lime this is the favourite one for agricultural purposes, on account of its great solubility and consequent fertilizing energy. I believe, however, that the phosphate prepared by precipitation from acid solutions of animal or mineral bone- phosphates, and named by me Gelatinous or Colombian phosphate of lime, is sufficiently potential for producing an active and rich vegetation at much less cost than the super¬ phosphate. Indeed, it is more than probable that this latter is changed into the former by the carbonic acid and other chemical in- 76 PURE FERTILIZERS . fluences of the soil before it has had time to exert much action by reason of its direct solubility when Arst applied. If this does not take place, then much of the bi-phosphate would be lost by reason of its solubility; for the rain would wash down into the subsoil all that might not be absorbed by the plants immediately after its application. This por¬ tion would be nearly the whole, as it is not rational to suppose that the vegetal absorp¬ tion could be instantaneous as to the total of any fertilizing element. If there should be any carbonate of lime, alumina, oxide of iron, or powdered mineral phosphate mixed with the pure bi-phosphate, as in the ordinary commercial “ superphos¬ phate”, the soluble phosphate of the latter is apt to become insoluble even in the bags, on account of the formation of di- and tri-phos¬ phate. When this occurs, the “ superphos¬ phate” is said, in trade parlance, to “go back". Precipitated Phosphate of Lime. This salt is said to be of the same chemical composition as the bone-phosphate, but with CHEMICAL DATA. 77 the addition of quasi-constitutional water in proportion varying from four to six equiva¬ lents. It may have the formula 3CaO, P 0 5 + 4HO, or sCaO, P 0 5 + 6HO, accord¬ ing to the manner in which it may be dried ; but most of this water can be expelled by kiln-drying. Practically considered, the cir¬ cumstances of its preparation influence also its composition. It is prepared always by precipitation with alkalies or alkaline earths, from solutions of the tri-or neutral-phosphate of lime in acids. My opinion is, that the precipitate com¬ prises all of the several phosphates, varying in proportion with the state of dilution and temperature of the solution and the kind and quantity of precipitant employed ; for I have certainly observed, that in its fresh pulpy state, it is not only very soluble in acetic and weak acids, but even splits into soluble forms under the action of water con¬ taining carbonic acid, ammonia, chloride of sodium, and many other saline matters. Very probably the carbonic acid of the soil may convert it gradually into bi-phosphate, di¬ phosphate, and carbonate of lime. 73 PURE FERTILIZERS . In its dry state it is scarcely less sensitive, and these properties give assurance that under the chemical influences of the soil it will prove as potential in fertilizing as the bi¬ phosphate, and at much less expense. In¬ deed, the bi-phosphate is first reduced, doubt¬ less to the state of precipitated phosphate, soon after it has been applied to the soil and the growing crops assimilate it in that form through the subsequent influence of carbonic acid and saline associates. It is on account of the composite nature and the tender properties above noted, that I have not given it a place in the preceding chemical table, and prefer to distinguish it by the title of Colombian phosphate of lime , when it is thrown clown by whiting, and Pre¬ cipitated phosphate when ammonia is the precipitant. Sulphite of Calcium-Phosphate . This is a product of the action of sulphur¬ ous acid upon tri-phosphate of lime, and its chemical and practical relations are given in chapter xvii. CHEMICAL DATA. 79 Phosphate of Magnosia . The chemical equivalent of magnesium is 12*o, and it forms tri-, di-, and bi-phosphates, corresponding in composition with the simi¬ lar salts of lime, thus :— Tri-phosphate or 3MgO, P 0 S ; Di-phosphate or 2MgO, P 0 5 , HO ; Bi-phosphate or MgO, P 0 5 , 2HO. For all practical purposes, this salt may be considered as phosphate of lime, since it as¬ similates to the latter sufficiently, in chemical and agricultural relations, to justify the union of them under one head. Moreover, it is rarely present to any large extent in mineral phosphates of lime. Carbonate of Lime. CaO, C 0 2 , = 50’oo. Oxide of calcium (CaO) - 28-00, or per cent. 56-00 Carbonic acid (CO2) - 22*00 „ 44*00 Chemical equivalent - 50*00 „ 100*00 In nature, the more common forms of this chemical salt are the different kinds of chalk, calcareous spars, marbles, and limestones. It is very widely diffused, being an element 8o PURE FERTILIZERS. of most of the river, spring, and other waters. It also enters into the composition of mani¬ fold other substances to a greater or lesser degree. When pure, it is perfectly white. On being calcined at a red heat in an open furnace it gives off its carbonic acid and be¬ comes caustic or quicklime (CaO). Carbonate of lime is insoluble in water, unless the latter should contain free carbonic acid. With this latter it forms bi-carbonate of lime, which is soluble. Carbonate of lime is also soluble in acids. It is almost an in¬ variable constituent of rock guanos or other phosphatic materials, but it does not impart any value to the latter. On the contrary, until the discovery of my new methods for the treatment of these rock guanos, it was a real pest, in that it consumed acid to extend the weight and dilute the strength of the fer¬ tilizer from those materials without forming any compensating product. According to Warrington, when carbonate of lime is present with phosphate of lime, as in mineral phosphates especially, it way¬ lays the atmospheric influences of the soil and monopolizes their action by its greater MOR FIT on the Manufacture of Fertilizers i -r B _ i i_ 1 -U=t J 1 [ 1 .... !L 1 1 L [ ] 1 M ■ ir DETAILS OF ELEVATOR LIFT & PLATFORM £ = 1 * - Plate 6. l n _ • ii 11 ii FRONT ELEVATION . 0 1 fc==t= SCALE OF FEET 6 7 8 -I I- - 9 10 -U it— r 77 =b 7 2 =i=: j'i i4 Feet -i-1 Trtibner & C° 60, Paternoster Row. Vincent Brocks, Day&San, Lith. Specially designed for Df Morfit's Work on Ferttlizers. CHEMICAL DATA Si chemical sensibility under the circumstances. Therefore the fertilizing action of the phos¬ phate associate remains dormant . until the carbonate has been decomposed by the car¬ bonic acid of the soil. When the raw mineral phosphate is to be converted into precipitated phosphate or superphosphate, this carbonate of lime con¬ stituent is the first to seize and appropriate the earlier additions of hydrochloric or sul¬ phuric acid. In this way 2*13 of hydrochloric acid (1*17) or I'oo oil of vitriol (1*846) would be con¬ sumed by each per cent, of carbonate of lime. The profitless product thus imported into the resulting fertilizer would be 1*29 hydro¬ chlorate of lime in the first case, and 1*72 of hydrated sulphate of lime in the second in¬ stance, according as one or other of these acids may have been used as the solvent. Hydrochlorate of lime (chloride of calcium) is not only an unprofitable element itself, in this connection, but also a deteriorating pre¬ sence, which renders the fertilizer product G 82 PURE FERTILIZERS. hygroscopic, and depresses the content of soluble bi-phosphate. So, also, the hydrated sulphate of lime thus forced into the fertilizer product crowds out soluble bi-phosphate, and renders im¬ practicable any high strength of the latter. Organate of Lime. In making a chemical analysis of a mineral phosphate or “ rock guano”, and after appor¬ tioning the lime according to its well-known chemical affinities, there is frequently a resi¬ due which, in our present state of know¬ ledge, cannot be allotted confidently to any associate element. I assume, therefore, until I can inform my¬ self better, that it exists naturally in combi¬ nation with the organic acids, and probably the silicic acid and alumina which may be present. Be that as it may, for all the practical pur¬ poses of this treatise, organate of lime is to be considered as carbonate of lime, and treated with acids accordingly, in the manufacture of fertilizers. CHEMICAL DATA. 83 Sulphate of Lime. CaO, S 0 3 , 2I IO=86'o. Oxide of calcium (CaO) - 28*0, or per cent., 32^56 Sulphuric acid (S 0 3 ) - - 40^0 „ 46'51 Water of constitution (2HO) i8'0 „ 20'93 Chemical equivalent - - 86 0 „ iocroo This substance is known in nature as Gypsum when amorphous or crystalline, and as Selinite or Alabaster if crystallized. It is white in the first, and colourless in the second form. It is soluble to the ex¬ tent of three parts in 1000 of water, but in¬ soluble even in dilute alcohol. Boiling hy- drochloric acid dissolves it more freely, and so also does a solution of common salt. By calcination at 212 0 to 300° F., it loses its water and becomes Plaster of Paris. Its presence in rock guanos neither adds to, nor detracts from, the value of the latter. Though it does not waste acid, it dilutes the mother-material without improving its value. The economy of the raw mineral would be better for its absence. 8 4 PURE FERTILIZERS. Fluoride of Calcium. CaFl = 39. Calcium (Ca) - - 20'0, or per cent. - 51*29 Fluorine (FI) - - 19-0 „ 48*71 Chemical equivalent - 39'0 „ ioo*oo Is known as Fluor Spar, and found gene¬ rally associated in nature with other minerals. It is also present in bones, to a small extent. Coprolites contain it, as also do some of the Phosphorites and Apatites. In its natural state it is yellowish, green¬ ish, or violet, and crystallized or crystalline. When heated, it becomes phosphorescent, and fuses at high degrees of temperature. Superheated steam decomposes it into lime and hydrofluoric acid. So, also, when fused with alkaline hydrates or carbonates, it is readily decomposed. It is itself used as a flux in the smelting of ores. It is nearly insoluble in water, but dissolves in very strong hydrochloric acid. When acted on by sulphuric acid it gives off noxious vapours of hydrofluoric acid, and it is on this account that mineral phosphates which con¬ tain much of fluoride of calcium are not a CHEMICAL DATA . 85 favourite material for superphosphating pur¬ poses. It also wastes acid in the usual mode of operating, but in the new processes herein described that defect may be lessened by careful manipulation in the digesting opera¬ tion. Every per cent, of fluoride of calcium would waste 273 of hydrochloric acid of specific gravity 1*17, or 1*28 of oil of vitriol of 1*846. Chloride of Calcium. Ca Cl = 55*5. Calcium (Ca) - - 20*0, or per cent. - 3603 Chlorine (Cl) - - 35*5 » 63*97 Chemical equivalent -55*5 „ iocroo Chloride of calcium is a constituent of numerous river, spring, and well waters, as also of many mineral substances. When pure, it is white, and so very soluble in water that it is one of the most deliquescent sub¬ stances known. By igneous fusion it is per¬ fectly dried; but, on exposure afterwards, soon absorbs moisture. It is also soluble in alcohol. Its presence gives a tendency to humidity to those substances which contain it. Solutions of chloride of calcium are de- 86 PURE FERTILIZERS. composed by solutions of alkaline carbonates or sulphates. With the first, carbonate of lime is precipitated, and alkaline chloride forms in solution. With the latter, sulphate of lime is precipitated, while alkaline chlo¬ ride remains in solution. This is effected by a double exchange of bases, as, for example, with sulphate of potassa, thus :— In solution. KC 1 . = Chloride of potassium. Ca CL + KO SO. As precipitate. CaO, S 0 3 = .Sulphate of lime. This property is taken advantage of in the new and original formulae of Chapters ix, x, and xi, for recovering (in the profitable forrk of ammonium or potassium chloride) the hy/ drochloric acid used for making the solution of the raw phosphate. Under other circum¬ stances, the use of this acid in the manufac- CHEMICAL DATA . 37 ture of superphosphate would be less favour¬ able to the economy of the product and also fatal to its perfect dryness. Oxide of Iron. Fe 2 0 3 = 8 o*o. As existing in mineral phosphate, it is most probably sesqui-oxide. Two equivalents of iron (Fe 2 ) - 56-0, or per cent., JO'OO ’ Three „ oxygen ( 0 3 ), 24.0 „ 30*00 Chemical equivalent - 80 0 „ 10000 In its mineral state it has only a feeble affinity for acids. Being thus passive, most of it is left undissolved, when mineral phos¬ phates which may contain it are treated in the cold with acids. Oxide of iron as well as alumina are profit¬ less constituents of mineral phosphates, both as to freight, expense, and fertilizing action. They not only waste acid but form objection¬ able compounds when the mineral is being converted into “ superphosphate.” Phosphate of Iron. Fe 2 , 0 3 , P 0 5 = 152*0. As associated with the other elements of mineral phosphates, it is possibly in the state 88 PURE FERTILIZERS . of phosphate of sesqui-oxide; and anhydrous. But, when freshly precipitated from acid so¬ lutions, it takes up four equivalents of water (4HO) and becomes hydrated. In this latter form, it differs from the anhydrous phosphate in important particulars ; for it is then soluble in water containing carbonic acid, and also in weak acids, with certain exceptions. The hy¬ drated, when heated to redness, becomes an¬ hydrous, and then it is only partly taken up even by strong acids in the cold. The freshly precipitated phosphate of iron, as above, has considerable fertilizing energy, more particularly when associated with ammo- niacal and potassa salts, as these promote its solubility, and the assimilation of its phos¬ phoric acid by the growing crops. Oxide of Aluminium. Al 2 , 0 3 = 51*4. In its mineral state it is generally anhy¬ drous, and not very sensitive to the action of acids in the cold. When freshly precipitated it becomes quite soluble, and even water, con¬ taining carbonic acid, takes up a portion. In this condition it is also completely soluble in solutions of caustic potassa or soda. CHEMICAL DATA. 89 When mineral phosphates which may con¬ tain alumina are treated with sulphuric acid, the product is more or less damp, unless this property should be corrected by the means prescribed in Chapters vm and ix. It is also a diluting constituent of the raw mineral without countervailing advantages. Phosphate of Alumina. Al 2 , (),, P 0 5 . The composition of the phosphate of alu¬ mina as it exists in the mineral phosphates, is even more doubtful than that of the phos¬ phate of iron constituent. In its natural hard state it is dissolved only slowly by the strong acids and the aqueous solutions of caustic potassa and soda. When precipitated from its solutions in acids, it is white, gelatinous, very soluble in acids, and more or less so in water containing carbonic acid and saline matters. When the precipitate is dried in the air, or by only moderate heat, these latter pro¬ perties remain unimpaired. In this latter condition it is serviceable for fertilization, upon the reasoning which has been noted for phosphate of iron, but in a greater degree. 90 PURE FERTILIZERS . Its formula, then, is probably Al 2 , 0 3 , PO s , 9H0 = 204*40, but it becomes anhydrous by ignition. The practical mode of converting phosphates of iron and alumina into fertilizers is described for redonda guano in Chapter XVIII. Organic Matter . This constituent of mineral phosphates is partly soluble and partly insoluble in acids. Most generally it contains little or no nitro¬ gen. In all cases it remains with the pro¬ ducts when the raw phosphates are converted into fertilizers by the processes described in this treatise. The action of the acids may modify its nature slightly, but the soluble portion goes with the precipitated phosphate, and the other forms part of the insoluble residue of the mineral. When the raw phos¬ phates are treated directly with sulphuric acid for their conversion into “ superphos¬ phate/’ the presence of organic matters' im¬ pedes the action of the acid in some degree, and also promotes its waste. In other re¬ spects it is merely an unprofitable diluting associate of the valuable components of the mineral. CHEMICAL DATA. Qi Silica and Sand . These form the part of mineral phosphates which is insoluble in either water or acids. They do not waste acids ; but are, neverthe¬ less, wholly valueless in themselves, being inert diluents of the raw material. Water. Is nearly always present in mineral phos¬ phates as an accidental or constitutional ele¬ ment. It is not in the way, chemically con¬ sidered, but swells, unprofitably, the bulk of the mineral and its cost of transportation. CHAPTER IV. THE GRINDING APPARATUS. In all extensive works the factory plant should comprise a grinding apparatus. But as such an arrangement involves the neces¬ sity of much space and a large amount of steam power, it is more economical, for mo¬ derate operations, to have the raw mineral powdered outside by a regular grinder. The business of the latter being a distinct branch of trade, I will devote a special chapter to the best means of practising it ifKConnection with hard mineral substances. The usual machines for reducing the mi¬ neral phosphates to fine powder, are either French burr stone mills of the ordinary pat¬ tern, or cast-iron rollers like a mortar mill. The first are employed by certain manufac¬ turers for grinding coprolites. If the raw mineral should be in large lumps, it would THE GRINDING APPARATUS. 93 have to be passed previously through a pair of iron cracker-rollers, in order to break it into smaller pieces, as a preparation for the mill. The Roller Mill. Much less expensive and more generally used are the cast-iron rollers. A mill of this construction, with rollers of eight feet dia¬ meter, will grind 200 tons of mineral phos¬ phate per week of days and nights. The steam-power required to drive it is equivalent to that of eight horses, and three or four labourers suffice to attend it. It is all-important that the rollers should be heavy ; and the pan may either revolve or be fixed. Some manufacturers prefer the fixed pan ; but the other arrangement is adopted most generally. Plate 1 shows a front elevation of a mill of this latter con¬ struction, set firmly upon a foundation t of mason work. The pan is b t and the crush¬ ing rollers are a d , carried by the cross shafts c c, bolted together in the middle. These cross shafts have the clips g g on them to keep the rollers a a in place. The pan b is 94 PURE FERTILIZERS. carried by a vertical spindle dd' resting in the footstep ft. The frame-work consists of the cast-iron uprights e e , the top entablature f and the endstay li. The arrangement for motion comprises the shaft / and its plummet blocks m m, the driving pulley k, the bevel pinion n , and the circular rack o , fixed to the pan. The rollers turn round on a fixed axis by the revolution of the pan, and the mineral is kept under them by means of the scrapers. Some engineers construct these mills so that the grinding and sifting may go on si¬ multaneously in the same machine. Then the plan b, as shown in the drawing, must be made with a false bottom, upon which the rollers are to run. This false bot¬ tom is placed at a distance from thq real bot¬ tom so as to form a chamber beneath for the collection of the sifted material, which passes through the fine holes with which the bottom is cullendered for the purpose. Or the pan may have only one bottom, and that cullendered, so that the material as fast as ground will sift through, and can be col¬ lected underneath by means of a shoot or otherwise. THE GRINDING APPARATUS . 95 When there is no such appendage to the mill, the sifting must be done by a separate instrument, as it is necessary to have the powder of uniform fineness in order that the subsequent chemical treatment may be facili¬ tated. The Sifter. This implement, shown in side and end elevation by Plate 2, consists of a strong tim¬ ber support carrying in the interior the two inclined and revolving cylinders of wooden frame-work, shown by the dotted lines at a a and b b'. Stretching over the circumference of the cylinders is ftne galvanized iron-wire cloth. The two sieves are connected by means of the shoot c ) and derive motion from the pulleys d and e. The two cylinders being set in mo¬ tion by steam-power, the mineral to be sifted is then thrown into the end d of the upper one, by a man standing on the platform, b , formed by the framing of the machine. The finer portion finds its way through the meshes and falls into the shoot c, which conducts it into the end of the lower cylinder b. The coarser portions which will not pass through g6 PURE FERTILIZERS. the meshes* are ejected at the end a of the top cylinder, the meshes of which should be coarser than those of the lower one. In like manner, when the finer portion of the upper cylinder falls into the lower one, that part which is fine enough passes through the gauze, while the portion that is too coarse finds its way out at the end b'. It would seem, from the practical experi¬ ence of manufacturers, that the most work to be got out of rollers even as large as eight feet diameter, is tons of powdered mineral per hour. With all these open mills there is an un¬ avoidable loss of powder, which escapes as fine dust, to the extent of several or more per cent., in many cases, according to its density. I feel confident, therefore, that better pro¬ gress and economy would be realised by the substitution of a different arrangement; or, in other words, by combining the powdering and mixing portions of the plant into one consisting of a Blake’s crusher and a Howel- Hannay mill. A sifting machine will be un¬ necessary, then, and all the loss by escaping dust would be prevented. THE GRINDING APPARATUS . 97 A crusher is necessary to reduce the mineral only when it is in very hard lumps of size larger than an inch or two square. At all times, however, it will expedite the work of the IIowel-Hannay mill, and economize the wear and tear of the machine to feed it with mineral of the size of inch cubes. Both of the above-named machines are American inventions, but can be obtained in England. The Blake crusher is made at the Soho Foundry, Leeds, and is used extensively in this country. The Howel-Hannay mill will not only reduce the mineral to fine powder, but serve also, and even better, for powdering the finished fertilizer as it comes from the drying kiln. Blakes Crusher. This machine is shown by Plate 3, in which fig. 1 represents a front elevation; and fig. 2 a plan of the entire machine. The circle d is a section of the fly-wheel shaft, and the dotted circle e is a section of the eccentric. A pitman on rod f connects the eccentric with the toggles gg, which have their bearings forming an elbow or toggle- 11 9 8 PURE FERTILIZERS. joint. There is a fixed jaw h, against which the stones are crushed ; and this is bedded in zinc against the end of the frame and held back to its place by cheeks i that fit in re¬ cesses of the interior of the frame on each side. There is also a movable jaw j, which is supported by the round bar of iron k passing freely through it and forming the pivot upon which it vibrates. An india- rubber spring l is compressed by the forward movement of the jaw, and aids its return. The frame a (see plan, fig. 2), which receives and supports all the other partA is cast in one piece, with feet to stand upoij the floor or upon timbers. These feet are provided with holes for bolts by which it may be fastened down if desired ; but this is unnecessary, as its own weight gives it all the requisite stability. The fly-wheels bb are on a shaft which has its bearings on the frame, and which is formed into an eccentric between these bearings. The pulley c on the same shaft receives a belt from a steam engine or other power. Every revolution of the eccentric causes the lower end of the movable jaw to advance MOR, SCALE OF FEET. i-I : :-i ,3 3 = Plate 7 : i- —! Triibucr &■ C: ,60. Pairr . &. n T }\cw. M OR FI T on the Manufacture- of Fertilizers. i>i .eciall'^ defii&iedforDTMoiiifs ‘A'ork -'n i H ertiuz^i Trubner &. C?,6Q,Pat£!iTiDSterRow. Vi; i‘ :ent Brooks , .D a.y &.bcn Lithi THE GRINDING APPARATUS . 99 towards the fixed jaw about a quarter of an inch and return. Hence, if a stone be dropped in between the convergent faces of the jaws, it will be broken by the next suc¬ ceeding bite; the fragments will then fall down lower and be broken again, and so on until they are small enough to pass out at the bottom. The readiness with which the hardest stones yield at once to the influence of this gentle and quiet movement, and melt down into small fragments, surprises and astonishes every one who witnesses the opera¬ tion of the machine. It will be seen that the distance between the jaws at the bottom limits the size of the fragments. The distance, and consequently the size of the fragments, may be regulated at pleasure. A variation to the extent of five- eighths of an inch may be made by turning the screw-nut m, which raises and lowers the wedge n, and moves the toggle-block o forward or back. Further variation may be made by substituting for the toggles gg, or either of them, others that are longer or shorter ; extra toggles of different lengths being fur¬ nished for this purpose. n 2 TOO PURE FERTILIZERS. This machine is made of several sizes. Each size will break any stone, one end of which can be entered into the opening be¬ tween the jaws at the top. The size of the machine is designated by the size of the opening ; thus, if the width of the jaws be io in., and the distance between them at the top 7 in., the size is called io by 7. The following table shows the several sizes of machines which are offered for sale ; the product per hour of each size/ of fine road metal from the hardest materials, when run with a speed of 250—the power required to perform its duty,—the whole weight of each size, and the weight of the heaviest piece when separated for transportation. Size. Product per Hour. Power required. Total Weight. Weight of Frame. Price Nett. On Wheels. cubic yds. Horse cwts. qrs. lbs. cwts. qrs. lbs £ s. d. £ s. d. 6 by 4 2£ 3 6 O O 18 O O 75 0 O 80 0 O 10 „ 7 3 4 78 O O 37 2 O 140 0 O 147 IO O IS » 7 4 * 6 108 O O 54 O O 180 0 O 190 0 O 20 „ 9 6 8 156 O O 74 O O 240 0 0 255 0 O 24 f 5 12 8 12 376 O O 80 0 O 350 0 O — I he whole length of the machines (accord- THE GRINDING APPARATUS. IOI ing to size) is from 4 to 10 feet ; the height being 5 to 8 feet; and the width 3 to 5 feet. The machines may be driven by any power less than that given in the table, and yield a product per hour proportionally. These machines may be set in one minute, to give the product any size from 2 inches, for road metal to fine gravel. The product of these machines per hour, in cubic yards of fragments, will vary consider¬ ably with the character of the stone broken. Stone that is “ granular ” in its fracture, like granite and most kinds of sandstone, will pass through more rapidly than that which is more compact in its structure. The kind of stone being the same, the product per hour will be in proportion to the width of the jaws, the distance between them at the bottom, and the speed. The proper speed is 200 to 250 revolutions per minute, and to make good road metal from hard compact stone the jaws should be set from id to inches apart at the bottom. For softer and granular stone they may be set wider. These machines can be fitted with a screen, as shown by fig. 1, when it is required 102 PURE FERTILIZERS. to assort the crushed stone into different sizes. The TIowell-Hanncty Mill . The mineral, having been reduced to the size of gravel by the crushers, is next to be subjected to the action of one of these centri¬ fugal mills, constructed upon the principle of reducing quartz, stones, fossils, and other re¬ fractory substances of a similar kind to fine powder by percussion—that is to say, by the sudden check of the momentum of a body moving at great velocity. To this end a closed circular chamber is provided, and set in either a vertical or horizontal plane. On a shaft in the centre of this chamber is mounted a plate or disc with arms projecting therefrom towards the inner periphery of the chamber, and this periphery, against which the material to be operated upon is intended to be dashed with great violence, is furnished with ribbed or angular surfaces. The material to be crushed is fed in at one side of the chamber (at the centre thereof) by a hopper, and when crushed it is discharged through an opening on the other side, the rapid rotation of the THE GRINDING APPARATUS. 103 arms on the central shaft while dashing the material against the ribbed or angular sur¬ faces of the chamber, causing also a current of air to carry off the powdered material at the discharge opening. A general view and details of this implement are shown by Plate 4, in which figs. 1 and 2 represent the side and end elevations of the improved machine. Fig. 3 is a plan of the same ; fig. 4 a side elevation of the machine, with one end of the crushing cylinder removed to show the con¬ struction of its parts ; fig. 5 is a plan of the interior surface of the cylinder ; fig. 6 is a modification of the same ; and fig. 7 repre¬ sents a section through the arms in the line x x of fig. 4. a a are two supporting beams, on which are erected four upright standards b, two on either side, connected together at top by beams c, these being in turn connected and braced together by cross rails d, on which are secured bearings e, in which is supported a revolving shaft f. On one end of this shaft is mounted an armed disc G, and on the other a driving pulley h. The disc G is enclosed by a casing 1, consisting of a cylinder j, and end-caps or covers k and k 1 . In the arrange- 104 PURE FERTILIZERS . ment represented in the drawing the cylinder j is armed on its interior with ribs, which may be either of a triangular form, as shown in figs. 4 and 5, or formed of pyramidal teeth, as shown in fig. 6, or they may be made in any other suitable form. Instead of teeth the inner surface of the cylinder may be left smooth, but the inventor prefers to use the teeth. The casing 1 thus constructed is firmly and permanently secured to the frame of the machine by means of screw bolts a and nuts b. On the end k next the frame of the machine, and at its centre, is cut an opening, through which the shaft f passes, whilst in the outer end k 1 of the cylinder, and at its centre is cut another circular opening d, but of larger size, for the purpose of feeding the machine with the quartz or other material to be pulverized, for which purpose a hopper of suitable shape and dimensions is attached to the machine. At or near the inner periphery of the cylinder there is cut through the inner end or disc k of the casing 1 another opening, to which is secured a carrying tube l, through which is forced by the current of air engen¬ dered by the rotation of the arms, the pul- THE GRINDING APPARATUS. 105 verized quartz or other substance as fast as produced, and by it conducted wherever de¬ sired ; or the spout may be let into the cylinder direct if deemed expedient. In this instance the arms, for the purpose of strength and to lighten as much as possible their weight, are represented as being cast on a disc g, which tapers from the shaft f out¬ wards, but if desired they may be cast on a hub, or in any other suitable manner con¬ sistent with strength, and they may either be made straight or curved. The disc on which they are cast (when a disc is used) may also be made in any suitable form consistent with the purpose for which it is intended to be used. On the inner surface of the cylinder ribs or teeth are formed, having the plane of their face set at right angles to the direction of the quartz or other substance as it is projected from the beaters or arms, under which circumstances they may either be made to run straight across the cylinder, as in fig. 5, or be cut somewhat of the form represented in fig. 6, so that the whole momentum of the quartz or other substance may be checked at once. As to the arms themselves, they may PURE FERTILIZERS . io5 be set at such angle to the shaft, and made in such form, curved or straight, as may be found best adapted for the most perfect execution of their work. In order to make the casing of the arms perfectly tight and strong, the ends or caps k k 1 are made to fit tightly over its ends, and the whole is then bolted firmly to the frame, and if deemed expedient for this purpose, a strip of lead, india-rubber, or other suitable material may be inserted between them. The operation of the machine is substan¬ tially as follows. The quartz or other mate¬ rial, broken to a suitable size, is fed in by hand, or by means of a hopper, through the open¬ ing in the outer cap k, when it is driven with great force and velocity by the arms or beater c of the disc G against the cylinder j, toothed or otherwise, and there reduced to powder, such parts as may not have been completely pulverized rebounding back, and being again projected by the arms against the cylinder until perfectly reduced. The pulverized ma¬ terial is carried and discharged by the cur¬ rent of air engendered by the rotation of the arms (or by other means suitably arranged THE GRINDING APPARATUS. io 7 for that purpose) through the tube l, and by it conducted wherever desired. If required, the cylinder j may be made to rotate to in¬ crease the speed in the opposite direction to the arms, in which event the machine would require to be suitably constructed for that purpose. It may be driven by a number 19 pulley. The frame of the machine is repre¬ sented as being made of wood, but it may be of iron. The rest of the machine is made of iron, the face of the arms and teeth being chilled. To render this machine effective, it must be rotated with great velocity, say from one to two thousand revolutions per minute, ac¬ cording to the diameter of the machine; and for this purpose a power of twelve to fifteen horses is required. The cost of a machine complete is from ^80 to ^*100. CHAPTER V. THE PLANT. A plant for the manufacture of fertilizers comprises numerous pieces, each of which should be constructed and arranged with a view to durability and facile management. Manual labour being a capricious, and time an important element of cost in evolving the products, this consideration is indispens¬ able to the economy of their manufacture. In other words, the apparatus must be made throughout of the best materials and workmanship, so as to save oft-recurring out¬ lay for repairs, and also be as nearly auto¬ matic as possible in order that it may move by steam-power, and do work quickly with the least possible personal attention. The pieces about to be described are those of general utility, and which constitute the actual requirements of a proper equipment. THE PLANT . 109 The supplementary apparatus pertaining to special processes will be set forth in their proper places. The Steam Boiler and Engine. The power of these implements must be according to the amount of work which they are to do. In all cases, however, it is much more economical and convenient to have them rather above than below the exact ca¬ pacity which may be required. The expense of a large boiler is very much less, propor¬ tionally, than that of a small one. Boiler power of 40 to 60 horses is a none too liberal allowance for a large factory which may require much steam for other purposes besides driving the engine. Even for a manu¬ factory of moderate extent the boiler should be of 25 horse-power, and the engine of 12 to 15 horse-power. In all cases, a smoke-consuming arrange¬ ment should be attached, so as to facilitate the burning of the fine and cheap coal dust. The Roasting Furnace . This is a reverberatory furnace with a I IO PURE FERTILIZERS. broad bed for roasting those mineral phos¬ phates which may contain sulphur, pyrites, and much organic matter. Its position is shown at p on the ground-plan, plate 16. The preparation of the raw phosphate in this manner economises acid and saves time as well as labour in the subsequent operations. A furnace, 16 feet long and 13^ feet broad, with an arch of the mean height of 2 feet from the bed, will have the capacity for roasting three tons of raw mineral at each charge; and four to six charges may be com¬ pleted in twenty-four hours. The Platform and its Accessories . This arrangement is shown by Plates 5, 6, and 7, and comprises a platform, an elevator, a lift, an acid reservoir, and a mixer. In the drawings, which are actual construc¬ tion plans to a scale, the side walls of the buildings are shown at a a, and the roof at b, c being a floor for the convenience of the workmen. The platform is seen at d, and is a strong- timber work supporting the acid reservoir v and the mixer b , in connection with the ele- M0RF1T on the Manufacture of Fertilizers. Digester or Solution Vat »* Plate 8. ELEV AT I 0 N. Fl G 2 Scale of Feet 9 Teel Fic3. =4 fc. irff a t 1 N o CO I tr o u. ui _i o CO dE I « Triihner& C°6Q, Paternoster Row. VlricentBrooks, Day&Son Lith. Specially designed for D r Morfit's Work on Fertilizers THE PLANT. 11 r vator a a a and the cage u, which brings up the carboys of acid to the reservoir. The vertical guides for this lift are shown by 11 f, and the gearing to hoist it by w w. The gearing x works the elevator, and the main shafting y hung to the roof of the building drives all the machinery. The platform o should be enclosed by a strong railing to prevent accidents ; and com¬ munication between the ground floor, it, and the floor c, must be established by means of a stairway with broad steps. The Elevator. This is to carry the powdered mineral from the floor to the mixer b. It is an endless flexible belt a a passing over a pulley at each extremity. A screw arrangement is for in¬ creasing the tension of the band in case this latter should become slack. Motion is com¬ municated by the counter shaft x driven from pulley on main shaft y. The belt being put in motion, dips up the powder from the floor beneath by means of the galvanized iron scoops or cups n n n , which, as they return downwards, drop it into I 12 PURE FERTILIZERS. the hopper of the mixer b, where it meets the diluted acid, issuing in a graduated stream at \ the same time from the reservoir v. At this moment the powder and liquid are thoroughly intermingled by the revolving spindle of the mixer and its blades preliminary to passing down by gravitation through the shoot c into the stone vats beneath. The Lift. The lift is for hoisting the carboys of acid to the tank or reservoir v. It is fixed to the rear of the platform, and consists of two cages u u, sliding between strong vertical guides t t ty and worked by the gearing w w , driven direct from pulley or main shaft y. While one is taking up the full carboys, the other is carrying down the empties. The reducing gear w w serves to diminish the speed and increase the power derived from the main shaft; and there are three pulleys, one narrow and fast, and the other two broad and loose, driven from the main shaft by one open and one cross belt. By shifting the position of these belts, so that THE PLANT. 113 one or the other is upon the narrow pulley, the motion is reversed. The whole of this driving arrangement is fixed conveniently to beams carried by the roof of the factory building. When dilute acid is to be used, it must be first emptied into a reservoir in the ground beneath, and thence pumped up by means of a pump constructed of lead and gutta-percha. This more convenient mode of hoisting is less applicable to strong sulphuric acid, which should be raised in carboys. So also hydrochloric acid, on account of its corrosive qualities, must be raised in car¬ boys or by means of the monte jus. The Acid Reservoir. This is a tank for holding the charge of acid which may be required for an operation. It consists of a wooden case v, lined with lead for sulphuric acid, and coated, inside and outside, with stearic pitch for hydrochloric acid. Such linings are necessary as protec¬ tion against the corrosive action of the acids. There should be two adjoining. The tops of the reservoir are level with the cage u at its i P URE EER TIL IZER S. 114 highest point,, so that when the lift brings up the carboys they may be moved readily on top of v. Then they are turned over, with their necks in the charging hole, so as to avoid any escape of fumes. As soon as a carboy is emptied, it must give place to a full one, until the reservoir is charged. The acid is drawn from the reservoir by means of a stone-ware tap. A suitable one, with bracket for fixing it in any convenient posi¬ tion, is made by Barnett, of Hoxton, Lon¬ don, and shown by figs. 1 and 2. The tall stem a is a pipe of lead or hard vul¬ canite connected with the acid reservoir, for the passage of the acid ; but a glass or vul¬ canite ball d, upon which a regulated pressure TIIE PLANT. 115 is applied by means of the screw and handle c, lessens or stops the flow, as required. By turning the handle so as to loosen the screw, the pressure of the acid forces up the ball d, and the liquid passes through the outlet f. In like manner by screwing down the ball, the outlet is closed. The packing e is made of felt. The body b of the tap may be made of lead, vulcanite, or stoneware, according as the tap is intended for the use of sulphuric or hydrochloric acid. This form of tap is not only cleanly and convenient, but very much less liable to be¬ come loose than any other kind. It were better to avoid the use of metallic nails in the construction of this reservoir, on which account the joints should be dovetailed and fastened with marine glue. The planks should be an inch and a half thick, and to give strength to the whole it must be bound with wrought-iron hoops or bands held tight by a coupling-screw arrangement at the ends. The Mixer . This is a wooden box, painted inside and 1 2 PURE FERTILIZERS . 116 outside with the protecting pitch already mentioned. It is shown in place by b , Plates 5 and 6. A sectional view of its details is presented by Plate 7, and the description which follows will be in connection with this latter drawing. The sides of the box are f f, and fitting into the top of this box is the hopper e, which receives the powdered mineral as it falls from the scoop cups c of the elevator. The acid enters the mixer at the base of the hopper e, through the wooden pipe t, coated internally with the protecting pitch just prescribed, and connected with the reservoir. The fast and loose pulleys l, drive the spindle d, which carries the blades. The spindle g, of the mixer, is made of very hard and tough wood, and has four blades h h, passing through it. They are set at right angles to each other and at an angle with the axis of the spindle, as shown at h h'. By this means they move like a screw, and force the mixed mass through the pass¬ age 1, into the collecting-box, whence it passes through the shoots n n, into the vats or receptacles beneath. This collecting-box THE PLANT. 117 may be omitted, and then the wet mass will fall d irectly from the mixer into the vats. The number of diverging shoots should cor¬ respond with the number of vats to be fed, and each one must lead into its special vat or receptacle. The passage from the hopper to the mixer is seen at m ; and a semi-circular wooden valve p, working on a spindle r, closes the open¬ ings of the shoots at will. These are better shown in fig. 3 (Plate 7), which is a plan of the collecting-box, with its top removed to expose the valves pppp; of which two (p p) are represented as closed, and two (p p) as open. All the parts should be covered with a protecting coating of the stearic pitch. The Digester or Solution Vat. The next implement to be installed is the stone vat in which the raw mineral is to be acted upon by the hydrochloric acid. It is shown by Plate 8 as constructed of flag¬ stones ; but any other material will answer which is proof against the action of acids. It is placed on the ground in advance of the elevator, and should constitute one of a row or scries of ten. h8 PURE FERTILIZERS. The drawing shows the whole arrangement in front, elevation and details. The form is that of a square box a, mounted upon a support of mason-work b, which rises from the ground about 18 inches. Each of the ends and sides, as well as the bottom, must be of an entire piece of stone without crack or fault. The bottom piece is large enough to cover the whole sur¬ face of the support b, which extends 16 inches beyond the circumference of the vat, in order to form a broad base c. The bottom piece c, is to be thicker than the sides and ends b c , and these latter are set into the former by means of a nicely- fitting groove cut around at about 12 inches from the circumference. In like manner, the ends are adjusted to the side-pieces by means of similar grooves in proper places. The front and back sides c c\ are 4 inches larger than the ends, in order to be grooved for receiving these latter. All the joints are first sealed with Portland cement or plaster of Paris, and then covered with a layer of stearic pitch. The whole is held firmly to¬ gether by the strong iron bands d d , with screw-nut ends e c. THE PLANT. 119 The bottom stone is 7 feet 8 inches square. The side and the end pieces have each a height of 4 feet ; but the length of the former is 5 feet 4 inches, while that of the latter is only 5 feet. This gives a clear ca¬ pacity of about 100 cubic feet to the vat, which is sufficient for the treatment of one ton of raw mineral and upwards at each operation. Surrounding the vat proper, and built up 2 feet from the base c, is a brick wall d, forming an enclosure of 4 inches diameter throughout, to act as a hot-air chamber e. This brick enclosure is to be capped with a thick flag-stone f, laid level, and kept firmly in place by means of cement and iron screw- bolts set into the brick-work. In the air-chamber, and surrounding the stone vat, is a circuit of iron tubes ff, for the circulation of a current of steam, in order that heat may be applied during the process of digestion. These tubes should be coated on the outside with a thick priming of oxide of iron paint, and then with a layer of stearic pitch io prevent rusting. Each vat is fitted with a cover made of cast 120 PURE FERTILIZERS. iron plate and protected with paint and pitch, as just mentioned. 'To facilitate its move¬ ment it is hung upon pulleys, as shown by g, h, i, with the handle of the chain in reach of the workman, and high enough to allow convenient stirring of the contents of the vat as may be necessary. At the rear of the wall and coinciding with the top f of the air-chamber, there is a strong wooden platform g, to facilitate the stirring of the contents of the vat and removing re¬ fuse matter. The surrounding hot-air chamber of the vat may be dispensed with, and the whole structure reduced to a simple stone box by incurring some extra expense in the first in¬ stance for platinum heating tubes a a, figs, i and 3 of the Plate. They should dip directly into the contents of the vat, and are therefore adjusted by a screw-coupling attachment gg } to the steam-fed pipe and is condensed by dilute sulphuric acid contained in a suitable vessel or receiver, as shown by d' y Plate 17. Coincidently, the material in the hopper again fills the space UR E PER TIL IZER S. powdered mineral phosphate of lime with dilute oil of vitriol, allowing it to dry and then powdering it. Assuming that no earth, ground plaster, or other material has been added to promote the drying of the product, and also that bone-ash or the best available “ Rock Guano” has been employed as the basis material, then, with the most careful manipulation, it is not possible to produce a “ superphosphate” of greater percentage strength than is expressed by the following analytical table :— (2) Bi-phosphate of lime (CaO, 2HO, P 0 5 ) - 32*00 Hydrated sulphate of lime (CaO, S 0 3 , 2HO) - 58*00 Undesirable foreign matters - - 1000 Total - 10000 Most generally, however, a more abundant material is employed, such as coprolites or marlstones, and these cannot be relied on for a higher uniform average of tri-phosphate of lime than 52 to 55 per cent. They contain, moreover, 12 to 15 per cent, of carbonate of lime. Hence, the product which represents the most of the superphosphate in the market 5 U PERPH OS PH A TING PROCESSES. 293 can have, at best, only the impoverished composition, per cent., shown by the follow¬ ing table :— (3) Bi-phosphate of lime (CaO, 2HO, PO.) - 26-50 Hydrated sulphate of lime (CaO, S 0 3 , 2HO) - 54/50 Foreign and undesirable matters - - 19 00 100 00 I have assumed in these calculations that no excess of acid or water has been used to prevent the “going back" of the bi-phos¬ phate into an insoluble form or to add weight ; that no foreign matter has been mixed in to promote the drying of the pro¬ duct ; and that the manipulations have been skilful throughout, so as to assure a per¬ fect conversion of the whole of the tri-phos¬ phate element into soluble bi-phosphate. I have also excluded from consideration all fluoride of calcium, which is generally present in mineral phosphates of lime to an extent varying from one to ten per cent., and would reduce, consequently, the ratio of bi-phos- phate in the product by raising that of the sulphate. I do this to give to the usual pro- 294 P LIRE PER TIL IZERS. cess and its products the most favourable ex¬ position that is possible. Yet, with all these concessions, its defects show forth most glaringly to reproach the manufacturer and to awaken the suspicion of the farmer or planter. It rarely happens that a superphosphate reaches the planter in such a pure state. It is most generally degraded either through fradulent design or unscientific and careless manipulation, to such an extent that com¬ mercial samples seldom answer to a higher test than twenty per cent., and often fall as low as fifteen to ten per cent, of bi-phosphate. These figures refer to actual bi-phosphate (CaO, 2HO, P 0 5 ), and not to their equivalent in tri-phosphate (3CaO, P 0 5 ). I make this explanation because it is the custom in the English market to offer and sell “ super¬ phosphate" upon this false expression of its real strength. When it is remembered that 1*00 of tri-phosphate of lime represents only 075 of soluble bi-phosphate, it becomes ap¬ parent, at once, that this deception is large in measure and unjustifiable. Evidence could not be more conclusive SUPERPHOSPHA TING PROCESSES. 295 than that which has been just noted against the defects of the methods in general use for making “ superphosphate”. It proves them to be alike discreditable to the manufacturer and unfair to his customers. Even supposing that the commercial product is always free from any designed or unintentional adultera¬ tion, and has uniformly the composition of the exemplar (3) on page 293, it is still an imposition, to a large extent, upon the credu¬ lity and confidence of the planter. Fertilizers are manufactured almost always in great commercial centres, and the custom¬ ers for them live often in distant parts not unfrequently remote from convenient chan¬ nels of transportation ; consequently the pack¬ age and freight charges upon a manure be¬ come important items for consideration. Sulphate of lime is a material common to every locality at trifling cost, and silica, sand, alumina, and oxide of iron are natural parts of every soil. Yet these form at least three- fourths of the “ commercial superphosphate” in question ; and the purchaser of every hundred pounds is compelled to pay for the packing and transportation of all that larger 29 6 PURE FERTILIZERS. worthless portion, in order to obtain the 20 to 25 per cent, of valuable bi-phosphate. To remove these great defects and to im¬ prove the advantages of the “ superphos¬ phate ” to both producer and planter, I worked out upon a scientific basis the prac¬ tical methods, described minutely in Chap¬ ters xiii and xiv. In my earlier efforts towards the construc¬ tion of these processes, I cleared away first only the carbonate of lime from the raw mineral by means of hydrochloric acid. This preliminary treatment, however, while it re¬ duced very materially the bulk and weight of the diluting influence, still left in the residue all of the sand, most of the organic matter, and much of the iron and aluminium com¬ pounds. Consequently, when sulphuric acid was added, subsequently, to convert the phosphate of lime constituent, it became not only more or less wasted, but caused a ten¬ dency to dampness in the resulting super¬ phosphate. Moreover, although the product was of very much higher quality than could be made from the mineral in its original crude 5 UPERPH OS PITA TING PR OCESS ES. 297 state, it retained a large enough proportion of foreign matters to keep down its character to that of “ commercial superphosphate”. These circumstances led then to the plan of treating the mineral phosphate with hy¬ drochloric acid and certain precipitants, so as to eliminate all the profligate elements. The cheap hydrochloric acid is made to do well the dirty work that is generally done badly by sulphuric acid ; and a pure tri- or di-phosphate of lime basis or “ superphos¬ phate” is evolved by self-compensating means, from even inferior mineral; so that all the subsequent operations of conversion are thus simplified and rendered economical to the utmost degree. CHAPTER XIII. ON THE MANUFACTURE OF PURE “ SUPER¬ PHOSPHATE” OF LIME. The precipitated phosphates or the Colom¬ bian phosphate of Chapters viii, ix, and x, are to be employed as the basis material. The use of either one of them simplifies the manipulation to the utmost, and reduces the expense of labour, time, and acid to the most economical degree. At the same time, the product is eminently superior both in quality and appearance. To convert it into “ superphosphate", it is only necessary to pass the well-washed precipitate through a mixing mill with the requisite proportion of sulphuric acid, and to lead the mixture into an enclosure where it may remain to ripen and dry. For this pur¬ pose, the precipitate in its wet pulpy state may be made to fall directly from the vat SUPERPHOSPHATE OF IHME. 299 into the pug-mixer (Plate 21), by means of an inclined gutter or shoot, a stream of acid being arranged to enter at the same time into the hopper of the mill while the latter is in operation. The pulpy mass and acid are made thus to mingle thoroughly. The enclosures into which the mixture is received are simply vats of mason-work, as presented by Plate 24. When the mass has remained in these enclosures several days it will have set hard into pure “ superphos¬ phate”, which is a mixture of bi-phosphate and sulphate of lime, and contains, in this instance, more of the former than can be pro¬ duced from any other known material. Every ro of dry tri-phosphate of lime re¬ quires O'Si of brown oil of vitriol for its con¬ version into soluble bi-phosphate. No re¬ gard need be paid to the small amount of di-phosphate which is present in the pulp ; for, although this requires less acid than the tri-phosphate, there are always some iron and alumina associates to make a compensation- balance in this connection. When the “ superphosphate” has become dry it is to be shovelled out, dashed to 3 °o P UK E FER TIL 1 ZER S. granular powder by means of one of Carr’s Disintegrators, and packed in bags for market. The pure state of this pulpy phosphate, and its loose texture, manifest their great advantage throughout this treatment. The composition of the product will be approximately as follows per cent. :— Soluble bi-phosphate of lime - - 39*00 Hydrated sulphate of lime - - 55‘00 Water - - - roo Sand and silica - '50 Iron and aluminium oxides and phosphates - 4*50 IOO’00 Its content of soluble bi-phosphate is equi¬ valent to 51*00 of pure tri-phosphate of lime. If the phosphate basis has been precipi¬ tated with due care, it will be free from iron and aluminium compounds and produce an equally pure superphosphate. Indeed, the di-phosphate, as made by my processes, can only contain those impurities by accident ; and, for that reason, and because it re¬ quires only half of the usual quantity of SUPERPHOSPHATE OF LIME. 301 oil of vitriol for its conversion, it is a prime basis-material for “superphosphate", in every sense. Assuming that the di-phosphate of lime is pure and de-hydrated, then every 100 lbs. will require 50 lbs. of brown oil of vitriol, with some water of dilution ; and form 160 lbs. of pure “superphosphate", having the following composition, approximately, per cent. Soluble bi-phosphate of lime (CaO, 2HO, P 0 5 ) 57-00 Hydrated sulphate of lime (CaO, S 0 3 2HO) - 41 00 Water, accidental - roo Sand and silica - - - roo Iron and aluminium oxides and phosphates - traces lOO’OO The manipulations are the same as have just been described, and the product, which is white, sets and dries very promptly. Its content of soluble bi-phosphate is equiva¬ lent to 75 per cent, of pure tri-phosphate of lime. Owing to the concentrated nature of di¬ phosphate of lime and its great potentiality as a fertilizer, it is eminently suitable for 302 PURE FERTILIZERS. direct application to the soil; and I have mentioned it as a basis-material for pure superphosphate, rather as an item of instruc¬ tion than with a view to recommend its use in that connection. It is almost too valuable for that purpose. CHAPTER XIV. - ON THE MANUFACTURE OF PURE AND WHOLLY SOLUBLE BI-PHOSPHATE OF LIME. The basis-material for this product is either the precipitated or Colombian phosphate of Chapters vm, ix, and x. It is to be taken in its wet pulpy state, after a good washing, directly from the precipitation vat, and led through a shoot to a broad box at the bottom of the elevator (Plates 5, 6, and 7), instead of into the pug-mixer (Plate 21), as was just pre¬ viously directed for the manufacture of pure “ superphosphate ”. In this instance, also, a weaker acid than the brown oil of vitriol may be used, as the resulting superphosphate need not be dry for the subsequent operation. Indeed, a certain amount of fluidity is even desirable. The chamber acid of 1*450 will answer. This contains, in one hundred parts by weight, 304 P URE PER TIL IZER S. 57*0 oil of vitriol (S0 3 , HO) of specific gravity 1*845, or 46*48 (SO,) of dry sulphuric acid. The use of this weak acid will be a great economy when the manure factory has a sulphuric acid work annexed, for all the expense of concentrating it by evaporation to commercial strength for exportation is thus saved. The sulphuric acid is to be raised to the reservoir v (Plates 5 and 6), near the mixer b (Plates 5, 6, and 7), by means of the lift u. It may be delivered, also, to the mixer direct from a reservoir below, by means of a leaden pump, with the mouth of its delivery-tubes so adjusted as to let drop the acid in as gradual flow as may be required. Every pound of dry tri-phosphate of lime requires 51*28 pounds of dry sulphuric acid (SO 3 ) for its decomposition, and this propor¬ tion is represented by 1 * 11 pounds of the dilute acid of specific gravity 1*450. The mass of pulpy phosphate having been brought by a gutter from the precipitation vat to the base of the elevator, is then to be carried up the belt and cups a a n n (Plates 5 and 6) to the mixer. As the pulp falls into . O) !> o 0 MORFIT on the Manufacture of'Fertilizers. Trubiier& C?.60,Paiemos«rRow- ViiieentBroakB. Day &.San, Lith. Specially designed for D r Morfits Work an. Ferniizers. BI-PHOSPHATE OP LIME . 305 the mixer a stream of acid should enter, so that the two may meet. Chemical action be¬ gins at once, and the decomposition of the phosphate goes on and becomes complete when the mass, after having fallen into the cylindrical vat (figs. 1, 2, 3, 4, Plate 22) be¬ neath, is stirred and heated at short inter¬ vals, during ten or twelve hours. If the contents of the vat should tend to stiffen, they must be thinned by the addition of water, for a certain fluidity is necessary. Without it the motion of the stirrer would be difficult, and the decomposition of the tri-phosphate might not be thorough. The mass consists, now, of liquid bi-phos- phate of lime holding a little sulphate in aqueous solution, and a solid which is wholly hydrated sulphate of lime. By repose, the latter will settle with most of the former resting upon it as a clear supernatant liquor. This liquor is to be drawn off through the cocks of the vat, or by means of a syphon, into the basin portion of the kiln. Plowever, as the mass retains yet a con¬ siderable portion of liquor, it must be washed x 306 P URE PER TIL IZER S. by the addition of fresh water. The liquor, instead of being drawn off as before, is allowed this time to percolate downwards through the mass into the lower chamber of the vat. To facilitate this process of dis¬ placement, the lower chamber is to be ex¬ hausted of air by means of the air-pump, for which there is a coupling-screw connection in the vat at m. The vacuum thus produced in the lower chamber causes the liquor to filter through rapidly from above. The washing is to be repeated once or even twice. The mass is then clean and ready to be pushed out by the motion of the stirrers through the holes and shoots / /, and wheeled away for sale as a cheap substitute for ground plaster. The wash-waters are to be run into the basin part of the kiln with the previous strong liquor, and heated until a film of crystals begins to form. At this stage, there must be great care to moderate the fire; for I have observed that the bi-phosphate of lime, when evaporated beyond the consistence of a wet crystalline mass, is apt to assume in part an allotropic condition which is com- BI-PHOSPHATE OF LIME. 3o; paratively insoluble. The heat must be stopped, therefore, when the liquor reaches the above-noted point. At this stage, also, it should receive its requisite proportion of drier. If, during the evaporation, there have been given off any white vapours of sulphuric acid, then the drier should be the Colombian phosphate, as it will thus neu¬ tralize the excess of sulphuric acid and add to the value of the product. Five to ten per cent, are to be added, and well stirred in to make a thorough mixture. The whole is then transferred to the basin of the kiln, where it is left to dry at a very moderate heat, not exceeding 180° to 200° Fahrenheit. If there is no excess of sulphuric acid in the bi-phosphate, then the best drier is the hydrated sulphate of lime, which is deposited from the chloride of calcium or mother- liquor, treated in Chapter xi. It may be added in its pulpy or moist state to the bi¬ phosphate, and the whole must be mixed thoroughly by raking. When there is any tendency to cake on the bottom or sides of the kiln, the mass must be kept detached by means of a hoe. The x 2 3°8 PURE FERTILIZERS. mass, when dry, is to be dashed into a granu¬ lar powder by means of Carr’s Disintegrator, previous to being packed into barrels for market. The product thus obtained is a mixture of 90 to 95 per cent, of pure soluble bi-phos¬ phate of lime with 10 to 5 per cent, of which¬ ever drier may have been used. Formerly, I used finely-powdered mineral phosphate of lime as the drier; but I have observed more recently that this substance is apt to reduce the bi-phosphate partly into di- and tri-phosphates, more particularly when there is no free sulphuric acid present. The chemical interaction which sets up this change is promoted by the incidental water of the mixture. Indeed, it is the undecom¬ posed portion of tri-phosphate of lime, which exists almost invariably in the ordinary com¬ mercial superphosphates, that causes the bi¬ phosphate portion to “go back", according to trade language, or become insoluble directly in water. Although the lift elevator and vacuum vats comprise a convenient arrangement for the manufacture of soluble bi-phosphate, they BI-PHOSPHATE OF LIME. 309 are not indispensable implements. A much simpler plant may be made to answer with such an easy material as the “superphos¬ phate", prepared as directed in Chapter xm. This material may be leeched of its solu¬ ble bi-phosphate portion by simply boiling it with water in the wash-vat for half an hour. Then, by repose, it divides into an upper stratum of liquor, which is aqueous bi-phos¬ phate of lime, and a lower deposit of solid hydrated sulphate of lime. The former is drawn off from the latter into the evapo¬ rating pan and reduced to a crystalline mass, as directed at p. 306. The solid residue in the vat is transferred afterwards to the stands (Plate 23), and allowed to drain. These draining stands are made of wood, and consist of a funnel- portion a , perforated with holes throughout its lower circumference, and supported by the frame-work c. They must be lined with a very coarse blanket or straw to prevent the choking of the holes with the solid matter. As the liquor percolates through, it is caught in the troughs b, which conduct it into a reservoir. PURE FERTILIZERS. 3io When all the strong liquor which it re¬ tained has passed through, hot water is to be poured upon the contents of each filter, and allowed to run through. This washing is to be repeated a second time, in like manner, and the united wash-liquors or drainings are then to be reduced with the previous strong liquor in the evaporating pan. The residual matter of the filters is the same as the exhausted matter of the cylindri¬ cal vats ; or, in other words, hydrated sul¬ phate of lime. It is far superior to ground plaster for dressing clover lands ; but must be thrown out as waste where there is no market for it. The “ superphosphate” and bi-phosphate of this process, unlike the bi¬ phosphate products of other methods of manufacture, do not “go back ” into tri- and di-phosphate after having been put into packages. It may be as well to note here that it has occurred recently to my mind, that the tur¬ bines used in sugar manufactories might serve well for separating the liquor from the solid portion of the superphosphate in the preparation of soluble bi-phosphate by this BI-PHOSPHA TE OF LIME. 311 process. It may be that the solid portion is too fine for this operation ; but, be that as it may, the suggestion is worth a practical trial. The saving of space, time, and labour, by this means, if it can be substituted for those prescribed, would be very great indeed. One thing is certain, that it would answer well for drying the precipitate of the wash- liquor; for there the deposit is coarse crystal¬ lized sulphate of lime, which will allow its liquor to go through the holes of the turbine without passing them itself. I, therefore, will describe this machine. It consists of an iron cage a a (fig. 6), placed in the centre of an enveloping case b b, of cast-iron, and attached to the base of a central and vertical axis c c, to which a cog d e/ communicates a motion of 1200 revolutions a minute. The walls of the cage are a fine cullender of very solid metal, and into this receptacle the stuff to be dried or cleared of liquor is to be placed. The machine being then set in motion, the very rapid volation drives the stuff against the walls, and sends the liquid portion through the fine holes. The solid is then to be removed for a new charge. So, 3 12 PURE FERTILIZERS. also, is the liquor to be drawn out of the jacket when it has accumulated sufficiently. The machine must be well dried always, when it is not in use, in order to prevent its becoming rusted. BI-PHOSPHATE OF LIME . 3 1 3 It is the utilization of the centrifugal force which constitutes the principle of this ma¬ chine and its mode of operation. The solution vat, with vacuum filter com¬ bined (PI. 22), which has been noted, is a cast- iron cylinder ff, lined with lead or coated with stearic pitch, raised upon a brick-work found¬ ation 0, and held firmly in place by the beams i i, bolted to the floor c. The perforated diaphragm, which converts it into a filter, is in segments k k , supported, first, by means of a strong ledge b b, running around the inner circumference a a , of the vat ; and, secondly, by a central column d, fastened to the bottom c } as shown by the cross section and plan views, figs, 2 and 3. This column carries at its upper surface the wooden footstep e for the end f of the shaft of the stirrer, and also a flange to sup¬ port the central portion of the segments gggg. These segments are cast with ribs on their upper face as rests for a plate simi¬ larly cullendered and coated. The interven¬ ing space between this double diaphragm is to be filled with clean coarse gravel or a blanket of loose texture as a filtering medium. 3i4 PURE FERTILIZERS. Fig. 4 gives an enlarged view of the stirrer, which is of wrought iron and covered with lead. Branch pipes s s s t leading from the steam-feeder rr, serve for heating the contents of the vat to facilitate solution ; and they enter from the outside to prevent inter¬ ference with the arms b b b of the stirrer. CHAPTER XV. THE MANUFACTURE OF COMMERCIAL SUPER¬ PHOSPHATE OF LIME. The usual rough and ready method of pre¬ paring this fertilizer is to make a mound about two feet high and six or eight feet in diameter, with a given weight of powdered coprolites, rock guano, marlstones, or other crude phosphate of lime ; then to shovel out the centre, so as to form a bowl with a rim or circumference ten or twelve inches thick, and fill the hollow with an equal weight of brown oil of vitriol previously diluted with water. This preparation being completed, the powder removed from the centre to form the bowl is put back by degrees; that is, by shovelfuls at a time, until all has been added. By means of a hoe, the mass is mixed next into a paste, and incorporated, finally, with 3i 6 PURE FERTILIZERS . the dry portion constituting the sides or walls of the bowl. It is left then for several days ; and, at the end of that time, if it should not be dry, it is to be treated with a sufficient quantity of ground gypsum, pow¬ dered mineral phosphate, sawdust, peat, or kindred powder to bring it into a dry state. Finally, it is broken down to a granular powder, by means of one of Carr’s Disinte¬ grators, and packed in bags or casks for market. This slovenly and unscientific mode of proceeding gives a product which has the important defects of very variable composi¬ tion, great dampness when iron and alumi¬ nium compounds are present, and excessive sulphuric acidity. The sulphuric acid, although in very large excess, by acting upon the lime in this man¬ ner, causes the sulphate of lime which it forms, to envelope that portion of the bone- phosphate of lime immediately beneath the outer surface of the particles of raw material, and make a coating sufficiently hard to pre¬ vent the further penetration of the acid. Thus a thorough contact of the acid with CO MATE R CIA L S UPERPHOSPHA TE. 31 7 every particle of the mass becomes impossi¬ ble, and the consequence is, that the acid does its work imperfectly. Moreover, the quantity of water of dilution necessary to moisten the mass sufficiently is in excess of the proportion which the chemi¬ cal constitution of the products demands, and this excess must be dried out, subsequently, by the use of absorbent powders which add to the expense of the fertilizer as well as to its already attenuated state, agriculturally considered, without imparting any counter¬ vailing advantages. When operating in open pits the evolution of vapours is discomforting always to the workmen ; and if coprolites or other raw ma¬ terial containing fluoride of calcium, should be under treatment, the emanations during the chemical action are positively injurious to health. In a commercial sense, too, it is desirable to give the product as high a fertilizing strength as possible, for manures are gene¬ rally distributed from grand manufacturing centres into remote and scattered corners of country often not very accessible by means of PURE FERTILIZERS. 318 railways or other less convenient means of transportation. A concentrated fertilizer will cost much less for packages, packing and freight, than one of low grade, and is proportionally more economical to the planter, who can temper it as may be required, or according to his own judgment, at the moment of using it, and with dry earth, peat, or ground plaster. One or other of these materials is always ready at hand in every district of land, and costs little or nothing, comparatively. To get rid of all the defects just specified, and to operate on large quantities of material economically as to time and labour, the work must be done by machinery. The chief im¬ plements for the purpose are an elevator and mixer, such as have been described in Chap¬ ter v, at pages 111-115. The acid reservoir, as well as the mixing box, should be pro¬ tected by a lining of thin sheet-lead. The acid may be mounted from a reservoir or trough below, by means of a lead pump, or in carboys, by means of a lift. A given weight of the crude phosphate of lime mate¬ rial in fine powder having been dumped on COMMER CIA L S UPERPHOSPHA TE. 319 the ground behind the mixing platform, is drawn up by the cups of the elevator, as ex¬ plained heretofore at page 112, and dropped gradually into the mixer, the stirrer of which is now set in motion. When the powder is being added, the acid must fall upon it with the proper amount of water of dilution, so that all may go through the mixing operation simultane¬ ously, as well as continuously, but in small charges at a time. To this end, the flow of acid from the reservoir or the pump, as well as that of the water from the hydrant, must be regulated accordingly, by means of feed¬ pipes and cocks of suitable bores. The en¬ trance of the acid and water in this manner causes a generation of heat, which assists the chemical action of the former upon the pow¬ dered phosphate very materially. The mass drops from the mixer in a moist state, and is conducted into a reception vat by means of an inclined tube, according to the manner described in a previous chapter. These receptacles or wells should be of stone or brick-work, with walls at least twelve inches thick, to give strength for resisting the 320 PURE FERTILIZERS. internal pressure of their contents. Twelve feet high and eight feet square, are very proper dimensions for them. They should have a wooden roof covered with felt cloth or paper boards, which have been saturated with stearic pitch. Plate 24 will give the idea of a series of eight of these wells under one roof gg- To the latter is fitted, by means of a coupling- joint, the tube a leading into the chimney hearth, for conveying away the noxious vapours generated within the vat. To prevent the escape of these vapours into the factory, the joints of this roof must all be kept tight. There must be also an opening d d , for the end of the inclined tube through which the mixed mass passes into the wells. The entrance to each vat is fitted with a very strong wooden door, about two inches thick, well steadied against the wall, as shown by be when the wells are about to be filled ; for, otherwise, the semi-fluid mass of the interior might press it down and cause great inconvenience and loss. o Th is prop arrangement c must be movable, COMMERCIAL SUPERPHOSPHA TE. 321 so that the doors can be put aside when the wells are to be emptied. Brown oil of vitriol of specific gravity 1700 is the kind of acid to be used. The total required will depend upon the composi¬ tion of the raw phosphate material, which must have been determined previously by chemical analysis. This once known, it is only necessary to weigh out the acid in the ratio of 1*21 pounds to every per cent, of carbonate and of o*8i pound to every per cent, of bone-phosphate of lime in the raw phosphatic material. A further quantity, equal to about eight to ten per cent, of the whole weight of the mineral may be added as an excess to provide for contingencies, through the presence of fluoride of calcium and iron and aluminium oxides and phos¬ phates. Many manufacturers who make their own acid use a weight of the latter equal to that of the raw mineral, but this great excess does not benefit the product. The water of constitution required for the products from each per cent, of carbonate of lime and each per cent, of bone-phosphate of PURE FERTILIZERS . 322 lime is 0*36 and 0*12 respectively. But the heat of chemical action always dissipates a large quantity, and provision against that waste must be made by using an excess of the equivalent proportion. As, however, the brown oil of vitriol contains already a con¬ siderable quantity, it will not be necessary to make this excess greater than 20 to 30 lbs. for every 100 pounds of this same brown oil of vitriol which may be employed. In that case, there will be no unnecessary delay in the drying of the contents of the wells. The mixture of powdered phosphate, acid, and water, will reach the wells in such a state of inter-action, that it will be found, within ten days, a hard mass of thoroughly decomposed raw material, consisting of bi-phosphate of lime, sulphate of lime, and the insoluble matters of the crude phosphate mineral. The per cent, of bi-phosphate will depend upon the per cent, of bone-phosphate which the raw matter contained. The presence of a large quantity of alumina in the latter may give rise to humidity in the product conse¬ quent upon the formation of sulphate of alumina. COMMERCIAL S UPERPHOSPHA TE. 323 At the proper time, the doors which close the openings are to be removed, and the dry mass is then shovelled out and reduced to powder by a Carr disintegrator or Howel- Hannay mill, and packed for market. It is indispensable to the economy of this method that the raw phosphate material shall be as free from carbonate of lime and fluoride of calcium as possible ; for this method, unlike the processes of the previous chapters, fails to afford a compensating pro¬ duct for the acid wasted by those compo¬ nents. If bone-ash has been the basis-material, the ^xoduct from 100 pounds will amount to 1 75 pounds, always provided that no excess of water or absorbent powders, as driers, have been used. This mixed product or “superphosphate”, as it is called, commer¬ cially, will be made up as follows :— Bi-phosphate of lime - 53 ‘ 00 Sulphate of lime—from carbonate - ipoo\ 1 c 97 ff „ „ tri-phosphate SO'OO ) Silica, organic matters, accidental water, etc say Total amount of product - 175 *° 0 324 PURE FERTILIZERS. This “ superphosphate” will have the com¬ position, per cent., noted at p. 292, Chapter XII. It is not possible to make a greater strength of bi-phosphate in this way, except with cer¬ tain kinds of apatite, phosphorite, and rock guanos, which contain a very high per cent, of bone-phosphate of lime with very little of other than organic matters. In such cases, there is little or no dilution or degradation of the product by inert mate¬ rials. But even with pure bone-phosphate of lime only 75*64 pounds of bi-phosphate (CaO, 2HO, P 0 5 ) can be obtained from 100 pounds of the former by this process ; and, at the same time, 110*25 hydrated sulphate of lime (CaO, S 0 3 , 2HO) are produced. Consequently, its maximum product per cent, would be only as given at pages 289 and 300, Chapter xn. It must be remarked, that either on ac¬ count of inferior mineral or bad manipula¬ tion, the admixture of absorbent powders or fraudulent practices, there is rarely more than 25 per cent, of bi-phosphate of lime at best, in commercial superphosphate. More COMME R CIA L S UPER P HO SP HA TE. 325 frequently, it falls to ten per cent., and even lower. In corroboration, here is the calculated composition per cent, of the best possible “ commercial superphosphate” that could be made with “ South Carolina phosphate”:— Bi-phosphate of lime (CaO, 2HO, P 0 5 ) - 25*38 Hydrated sulphate of lime (CaO, S 0 3 2HO) - 52-82 Iron oxide and alumina - 5 ' 7 ^ Organic matter - - - 5*14 Sand and silica - 8*92 Water - - - - 1*96 100-00 This analysis represents a product of only 155 6 pounds from 100 pounds of raw mine¬ ral ; that is of the rarest purity; but in prac¬ tice it would be so much larger from the presence of driers, excess of water and acid, as to depress the quality of the “ superphos¬ phate" at least twenty per cent. In Great Britain, generally, the analytical report upon a sample gives its equivalent value in tri- or bone-phosphate as the real content, seemingly, of the bi-phosphate. Thus, a sample of superphosphate from 326 PURE FERTILIZERS . bone-ash containing only 31 per cent, of actual bi-phosphate will be sold as having the richness of 41*00 per cent.; these latter figures expressing the amount of tri- or bone- phosphate of lime to which the former are equivalent. CHAPTER XVI. horsford’s baking powder This modern substitute for yeast, in the manufacture of bread, originated with Eben. N. Horsford, Professor of Applied Chemis¬ try in Harvard University, of the United States of America; but it is known in Great Britain and on the Continent as the Liebig- Horsford Baking Powder. It is a mixture of pure bi-phosphate of lime (CaO, 2HO, P 0 5 ) and bi-carbonate of soda (NaO, 2C0 2 ), in chemical equivalent proportions. To make the acid element, it is necessary to have a very pure tri-basic or bone-phos¬ phate of lime. This is to be prepared by dissolving bone-ash in a clean wooden vat, with quite pure and dilute hydrochloric acid, allowing to settle well, drawing off the clear liquor into a clean wooden vat, and then 328 PURE FERTILIZERS. adding pure aqua ammoniae until there is no further precipitation, or rather until the mix¬ ture blues a piece of red litmus paper dipped into it. After repose, the clear supernatant liquor or aqueous solution of chloride of am¬ monium is to be drawn off, evaporated to dryness as crude crystalline ammoniacal chloride, and barreled for market. The resi¬ due is then treated with water, stirred, al¬ lowed to repose, and the clear liquor drawn off as before, and mixed and evaporated with the previous liquor. A second washing, with a fresh addition of water, is now necessary to remove the last traces of ammoniacal salt, and this wash-water must also follow the course of the preceding two into the evapo¬ rating pan. The precipitate is next transferred to a series of filters, and there allowed to drain well. These filters are shown by Plate 25: a being the wooden support, c the coarse linen filtering cloths, and b the wooden pail for receiving the filtrate. Assuming that the bone-ash under treat¬ ment contains a liberal proportion of bone- phosphate and carbonate of lime—that is, HORSFORD'S BAKING POWDER . 329 72 4- 9 = 81—then the quantity of pure hydro¬ chloric acid (specific gravity 1*170) required for the solution of every hundred pounds of ash would be 118 pounds. Should the acid be weaker than specific gravity 1*170, a pro¬ portionally greater quantity must be used. It will be more convenient and economical to make each and every operation with 1*39 tons of bone-ash, so that the amount of pre¬ cipitate shall equal very closely one ton of tri-basic phosphate of lime. The washed and drained precipitate from the 1*39 tons of bone-ash, is then to be trans¬ ferred to a clean wooden circular vat, fitted with a wooden stirrer. This vat does not need any cover, nor yet to be coated with re¬ sisting paint, but is to be fitted with a “blow- up" or open steam-tube. Brown oil of vitriol of specific gravity 1*700, and made from sul¬ phur, so as to be free of arsenic, is now to be poured upon the precipitate in a thin stream during constant stirring. It must be diluted previously with its weight of water, or, if more convenient, this proportion of water may be mixed instead with the precipitate in the vat. The necessary quantity of brown 330 PURE FERTILIZERS. acid (1700) for the precipitate, which is equi¬ valent to one ton of pure dry tri-phosphate of lime, will be sixteen hundred - weight. After all the acid is in, and the mixture has been well stirred, it is to be left for a week or ten days, care being observed to rouse it in the interval by frequent stirrings. The sulphuric acid abstracts two equivalents of the lime to form sulphate of lime, and leaves the remaining equivalent in combination with the whole of the phosphoric acid as soluble bi-phosphate. At the end of this time, the decomposition will have been complete, and clean water is then to be added, in order to thin out the mass. To promote this end, the stirrer must be put in motion. The whole is now left to repose, in order that the clean liquor may rise to the top. This is an aqueous solution of bi-phosphate of lime, with a little sulphate. All the rest of the sulphate of lime remains as insoluble matter. It, however, yet retains some of the soluble phosphate, which must be washed out with fresh water in the manner just described. This wash-water, when drawn off, is to be mixed with the first or previous liquor. M 0 R.F 1 T on the Manufacture, of 'Fertilizers. c Cl 0 6G z o f- < > Ul uJ I I »-• z !u < ^ Ou U. o UJ J < Ok CO 1 I g&» I rribner Sc C°, 60, Paternoster Row. Viixent Brooks, Day &.Son, Lith. Specially designed for D r Morfit's Work, on Fertilizer s HORSFORD'S BAKING POWDER. 33 i To remove all suspended matter the mixed liquors must now be strained through a filter-cloth of sufficient fineness, or allowed a day’s repose, in order that it may settle clean. The clear runnings are then to be evaporated in shallow enamel-lined iron pans, to a thick syrupy liquor, at which stage sufficient wheat- flour is to be stirred in to convert it into a dry powder. These pans a (fig. 7), arc made of large size and superior quality, by T. and G. Clark and Co., Wolverhampton. They can be set in brick-work, over a naked fire ; but the drawing represents one with a cast- iron jacket b, so that it may be heated with steam. The price of the latter, with fitti ngs, is /"5 : i° for one of 25 gallons capacity; 33 2 PURE FERTILIZERS . £11 for one of 50 gallons capacity; and £21 for one of 100 gallons capacity. It is necessary that the powder shall be perfectly dry when cold, because any con¬ tained moisture would cause it to act prema¬ turely upon the bi-carbonate of soda with which it is next to be mixed. The powder would thus become stale, as it were; or, in other words, inert, as a yeast substitute. The proportion of bi-carbonate of soda to be mixed with the bi-phosphate of lime is 0'965 pound for every per cent, or pound of bone- or tri-phosphate of lime represented by the acid powder of bi-phosphate of lime. To the ton, therefore, produced, as just di¬ rected, there must be added eighteen hundred¬ weight and three-quarters of bi-carbonate of soda. Complete mixture of the two powders must be made by means of a Howel mill, kept well clean, interiorily, for the purpose. The baking-powder is then ready to be packed in glass bottles with cork stoppers, containing in their centre a wooden measure for holding sufficient powder to produce the rising of two pounds of fine white flour. This sufficient quantity is one ounce. The HORSFORD'S BAKING POWDER. 333 form of this stopper is shown by fig. 8, in which b represents the cork exterior, and a the interior wooden measure. This arrange¬ ment is not only convenient for packing, but also for the consumer, who would need, otherwise, a pair of scales to weigh out the proper quantity at each and every baking. The two powders may be packed and sold in separate bottles, to be mixed at the time of use. In such case, the measure- Fig. 8. stopper of the bottle containing the acid powder must have the capacity for exactly one half ounce. On the other hand, the stopper-measure of the other bottle must hold fully one half ounce. In all cases, the measure must be “ struck that is, the con¬ tents are to be level with the top, for which purpose any excess must be scraped off with a knife, so as to leave a smooth flat surface. 334 PURE FERTILIZERS . Directions for Use . The flour having been sifted into a clean wooden bowl, is to be incorporated dry with the mixed powder in the proportion of one ounce for every two pounds of flour. Or, if the acid and alkaline powders are separate, then one half ounce of the first, and rather more by a grain or two of the latter, are to be used to every two pounds of flour. After thoroughly incorporating the whole by means of the hands, and throwing in a little table- salt, sufficient cold water or milk is next added to make a soft and rather thin dough. In the meantime, the pans must be made warm and the oven quite hot. Then, after having kneaded the dough only so much as is necessary to make it perfectly homogene¬ ous, it is to be put into the pans so as to leave about one-fourth of the top space free, and baked immediately. Thorough baking is indispensable to prevent doughiness of the crumb portion of the bread when stale or cold ; and, therefore, the loaves must not be removed from the oven until they are quite brown. HORSFORD'S BAKING POWDER. 335 The pans should be of tin plate and round, about six or seven inches in diameter, and three to three and a half inches in height. The bread as thus made from white flour is light, sweet, and very superior. Care must be taken not to use less than the pre¬ scribed quantity of flour for the bread; other¬ wise, the latter will have a peculiar saline taste. Two pounds of good flour yield from three to three and a quarter pounds of baked bread. The chemical action which takes place in the mixture of flour, baking-powder, and water, is as follows :—the bi-carbonate of soda neutralizes the bi-acid equivalent of the bi-phosphate of lime, and phosphate of soda, with precipitated phosphate of lime, is formed. Carbonic acid, being thus disen¬ gaged as gas at the same instant, rises through the dough, expands it, and makes it light and porous. There is no loss of flour as by the process of raising by yeast. Moreover, the phos¬ phates separated by the bran are thus re¬ stored to the flour. 336 PURE FERTILIZERS. Brown Bread. The ordinary bran-meal, and also the “ whole ground flour”, will make very supe¬ rior bread with this powder, both as to light¬ ness and agreeable taste. A little salt must be added ; and, to prevent doughiness of the crumb part, the proportion of powder must not be less than one ounce of the mixed pow¬ der to two pounds of whole ground flour. Even as much as two and a quarter ounces of mixed powder may be used with four pounds of the flour without imparting any perceptible saline taste to the bread. This bread keeps well, and is far superior to that made from the same flour by any other method of raising. The ordinary bran-bread meal requires, at furthest, only one ounce of mixed powder with two pounds of meal. The precautions directed already, as to the baking, are to be observed more strictly with regard to these brown breads than to those from fine white flour. HORS FORD'S BAKING POWDER. Gout-Bread and Confectioners Cakes. The preceding mixed powder, with a cer¬ tain amount of sesqui-carbonate of ammoniac in place of a portion of the bi-carbonate of soda, becomes an excellent baking-powder for bread suited to gouty patients. Neutral phosphate of ammonia (2NH3, 2HO, TO-, IIO) is thus introduced into the bread, and this salt entering the system, keeps in solu¬ tion the uric acid and urate of ammonia, which are otherwise painful secretions in that disease. At the same time, there is given off a larger amount of carbonic acid than from the soda-powder, and this property adapts it admirably for making sweet cakes. So long as the ratio of carbonate of ammonia is not in excess, the bread and cakes will have only an agreeable taste and wholesome condition. To prepare the powder properly, one hun¬ dred pounds of the dry bi-phosphate of lime are weighed and put into a wooden trough. Assuming that ten pounds of flour are con¬ tained as drier in this hundred of powder, then there are ninety of acid or bi-phosphate of lime to be neutralized. For this purpose z PURE FERTILIZERS, 72 pounds of finely-powdered sesqui-carbo- nate of ammonia (2NH3, 2HO, 3C0 2 ) are to be sifted in, and thoroughly intermixed with the acid powder. In other words, the equi¬ valent proportion of sesqui-carbonate of am¬ monia is o'8o for every per cent, (ro) of pure, anhydrous bi-phosphate of lime. In the same manner three hundred pounds of the acid powder are to be thoroughly in¬ termixed with 275 pounds of bi-carbonate of soda. These two double powders are finally mixed and sifted together, so as to produce an uniform fine powder. The com¬ pound powder thus formed is the baking- powder for gout-bread and sweet cakes. One ounce suffices for two and a half to two and three-quarter pounds of flour. It is to be used in the manner as directed for the soda powder, and the same precautions in baking are to be observed. It is indispensable that all these powders shall be kept dry until after they have been mixed with the flour previous to making the latter into dough. CHAPTER XVII. gerland’s sulphite of tri-phosphate of LIME. The action of sulphurous acid upon tri-phos¬ phate of lime has been studied specially by Dr. B. W. Gerland, who was the first chemist to give it attention ; and to him we are in¬ debted for all of our practical knowledge on this interesting and comparatively novel sub¬ ject. Sulphurous acid in aqueous solution dis¬ solves phosphate of lime with considerable energy; more particularly when the latter is in an artificial precipitated state. The natural mineral forms of it are only less soluble than the artificial, and in proportion to their greater or lesser density of structure. The resulting solutions are perfectly clear, and contain phosphoric acid and lime in the same proportions as the original substance. 340 PURE FERTILIZERS. As sulphite of lime is very largely insolu¬ ble*" in water, even though the latter may be saturated with sulphurous acid, it is evident that this salt cannot have been formed ; and, therefore, the sulphurous acid must have dissolved the phosphate of lime without de¬ composing it. The sulphurous acid thus acts quite otherwise than sulphuric acid, which latter, under corresponding circum¬ stances, would produce sulphate of lime, to¬ gether with bi-phosphate of lime. The relative energy and proportion in which the different forms of tri-phosphate of lime are dissolved by an aqueous solution of sulphurous acid are shown by the follow¬ ing table. The solutions were obtained by suspending the phosphate material in water and passing sulphurous acid gas through the mixture. One thousand cubic centi¬ metres of the solution, made in this manner, were found to contain :— * Gerland’s estimate is, that ioo cubic centimetres of the saturated solution contain 8-996 grammes of sulphur¬ ous acid and 0-258 gramme of lime, which are equivalent to 0*553 gram me of sulphate of lime. SULPHITE OF TRI-PHOSPHATE. 34i Components. Pure Pre¬ cipitated Tri-phos¬ phate of Lime. Bone Ash. Bone Ash. Pieces of Bone. Pieces of Bone. Pieces of Bone. Pieces of Bone. Pieces of Bone. Sulphurous acid grammes. 218*38 grammes. I4I 82 grammes. 159-446 grammes. 36019 grammes. 36*848 grammes. 35-597 grammes. 33-536 grammes. 32 - 55 0 Sulphuric acid 0-70 trace — 1*664 1-748 2-058 I -320 I *185 Lime 101 -79 59^9 5 I '374 20-787 z 9- 2 33 20*496 18-589 I 9 - 35 ° Magnesia — 2-79 2-896 0-582 0-460 trace trace — Phosphoric acid 82 89 47-42 40-093 15-287 i 4 " 5 °S 15-925 15-030 I 4 - 45 I Total 403 -76 251*72 253-809 74-339 72-796 74-076 68- 4 75 67-536 Specific gra- ) vity of the > solution - \ I -3000 at 4 8:2 c F. 1 *1708 at 53 ' 3 °F. i -1881 at 57 -i°r. I -0650 at 6i° F. 1 -0600 at 63° F. 1 '06S0 at 64-2°F. £-0611 at 50 ° F. I -0612 at 4 6-2°F. These results show that in the stronger solutions there is one equivalent of tri-phos¬ phate of lime to six equivalents of sulphur¬ ous acid ; while those which are weaker con¬ tain the latter in the ratio of only five equi¬ valents to one of tri-phosphate. The solutions prepared from bone-ash and bone-dust contain more lime than their con¬ tent of phosphoric acid requires to form tri-phosphate; but the proportion of these is nearly uniform in the bone. The following table shows the composition 342 PURE FERTILIZERS . of the excess of bone-ash which was sepa¬ rated from solution No. 3, after having been washed and dried :— Matters insoluble in hydrochloric acid - 5-42 Sulphurous acid - trace Sulphuric acid - - 0’29 Carbonic acid _ - 0*90 Lime - - 48-25 Magnesia - - trace Phosphoric acid - - 38-59 Moisture and deficiency - 6-55 100*00 The proportion of phosphoric acid to lime is one equivalent to 3'172; whereas the liquor No. 3 held them in the ratio of one to 3-268 ; and, moreover, the latter contained all the magnesia. Although the excess of bone-ash had undergone only this slight chemical change, the pieces were completely disinte¬ grated and reduced to fine powder. These solutions have the odour of sulphur¬ ous acid, but in less degree than an aqueous solution of the gas itself; and, on exposure to air, their surface becomes covered with brilliant crystals. The weaker solutions re- SULPHITE OF TRI-PHOSPHATE. 343 main unchanged, in closed vessels, for an in¬ definite length of time; but the stronger ones require to be kept at temperatures below 64° Fahrenheit, in order to maintain their preservation. Above this degree, the latter decomposes and drops a deposit which in¬ creases, progressively, for days. This de¬ posit is a mixture of sulphite and di- or neutral - phosphate of lime, in which the former predominates. At the same time, the solution becomes richer in phosphoric acid, until finally this and the lime are present in about equal molecular proportions. The same decomposition will take place even during the preparation of the solution, if the temperature is allowed to rise above 64° Fah¬ renheit. When exposed in vacuo, the solutions crystallize into well formed hexagonal pyra¬ mids composed of di- or neutral-phosphate and sulphite of lime with much water of constitution. A mixture of variable proportions of di¬ phosphate and sulphite of lime is also preci¬ pitated from the solutions when the latter are boiled under reduced pressure, diluted with 344 PURE FERTILIZERS. alcohol, or treated with a current of carbonic acid gas. Although solutions of phosphate of lime in sulphurous acids have the strong tendency to form the compounds as just explained, it is remarkable that they lose it when heated rapidly and boiled under atmospheric pres¬ sure. Thus manipulated, they drop their phosphate completely as a definite chemical compound of tri-phosphate of lime with sul¬ phurous acid and water, which corresponds to the formula gCaO, P 0 5 , S 0 2 , 2HO. It is in the form of a crystalline white powder, which settles readily, but is very light when dried. The residual sulphurous acid escapes with the aqueous vapour. This compound differs from other sulphites in not having any greed for the oxygen of the air, as it remains unchanged when wet, dry, or heated. It holds its water up to 284° Fahrenheit, and at higher temperatures; then water is given off with accompanying vapours of sulphur, sulphurous acid, and sulphuric acid. The sulphite of tri-phosphate of lime is neither soluble in, nor acted upon, by cold or SULPHITE OF TRI-PHOSPHATE. 345 boiling water. Dry chlorine and ammonia gases are without effect upon it; and aqueous ammonia affects it only slightly. A mixture of gaseous ammonia and oxygen or air is absorbed gradually by the sulphite, and pro¬ portionately sulphate of lime is formed. Sul¬ phuretted hydrogen turns the sulphites yel¬ low by developing free sulphur. Strong acids decompose it, oxalic acid more slowly and less perfectly, and weaker acids, like the acetic, with little or no energy, unless the air has access. A weak aqueous solution of iodine,—containing*, say I2’69 grammes of iodine to the litre,—dissolves the compound by promoting the oxidation of the sulphurous acid constituent; and this reaction affords a ready means of estimating the same. The sulphite of tri-phosphate of lime has not yet been made in any other way than that just described. Phosphate of lime, when digested with its solution in sulphurous acid, is not changed ; but the contact disposes the latter to form, gradually, sulphite of lime, which becomes mixed with the phosphate. This change progresses to such an extent, within a few days, as to cause a perceptible 346 PURE FERTILIZERS. diminution of the specific gravity of the liquor. Alkalies and alkaline carbonates throw down precipitates from these solutions, which differ from the sulphite of tri-phosphate of lime in both appearance and composition. The Method of Manufacture. The foregoing explanations will render easy the proper understanding of the pre¬ paration of the sulphite of phosphate of lime on a practical scale. Figs. 9 and io show the construction and arrangement of the necessary apparatus for making it at the rate of thirty hundred¬ weight every twenty-four hours. The raw phosphate material is to be placed in the four wooden cisterns or vats cq c 2 c 3 c 4 , and upon a false-bottom b, in order that it may not be washed away. If the bone-ash or phosphate material is finely divided, it yields promptly to the dissolving action of the sulphurous acid which is now to be led into it; but, in order to increase the strength of the solution progressively, it must be pumped repeatedly from these cisterns or SULPHITE OF TRI-PHOSPHATE. 347 ( I I \ 1 34§ PURE FERTILIZERS. J I I SULPHITE OF TRI-PHOSPHATE . 349 vats into the towers about to be described. The pipes ?! p 2 p 3 p 4 , which are fitted seve¬ rally with taps, and, connected with two double-acting pumps a a 2 , serve to produce this circulation, which is to continue until the liquor assumes a density of 12 0 to 15 0 Twaddle. The pumps deliver the liquor at the top of the condensing towers, through the spouts S! s 2 s 3 s 4 . These latter communicate by means of plug-holes with three short spouts Ui u 2 u 3 , placed beneath and at right angles with them. The latter pierce or extend through the sides of the three towers r 1 t 2 t 3 , and allow the liquor to fall upon the sieve d, which promotes its uniform distribution. The towers are built of flag-stone, after the manner of those used for condensing hydro¬ chloric acid, or may be constructed of sheet- lead. Each one is fitted, at some distance above the bottom, with a diaphragm of lath- work e, as a support for the pieces of coke, broken tiles or twigs, with which it is to be filled. The sulphurous acid is without action on these percolating media, and they can be placed readily, so as to facilitate the free / 350 PURE FERTILIZERS. passage of either gas or liquor through their interstices, and, at the same time, produce a wide expanse of surface. The towers are fed at the top with water which, filtrating through the coke, absorbs the gaseous sulphurous acid entering at the same time from the sul¬ phur furnace at f. The water thus acidulated passes out at the bottom of the towers into the wooden cisterns containing the phosphate material. The sulphurous acid is generated as gas by the combustion of sulphur on the re¬ fractory-brick floor of a suitable furnace simi¬ lar to those used in the manufacture of oil of vitriol. Sulphuretted ores may be substi¬ tuted for sulphur; and this means of con¬ centrating them , by roasting , for more econo¬ mical transportation to distant markets or smelting-works , opens a way for the profit¬ able production of the sulphite of tri-phos¬ phate of lime in those remote places where crude phosphate material abounds and sul¬ phuric acid is to be obtained only at a cost which is too great for its employment in the usual processes of manufacturing fertilizers. After the gas has entered the first tower it l ! i s LIBRARY SULPHITE OF TRI-PHOSPHATE. 35i ascends to the top, thence passes into the next, and pursuing a downward course, finally ascends into the third tower, from which the uncondensed portion is conducted off through the draft pipe o, to the chimney, or by means of an aspirator. This coursing of the gas brings it into broad contact with the water, which, in its turn, is sent through the pumps and the system of spouts de¬ scribed already, to the top of the towers, whence it spreads itself over the coke and arrives eventually at the bottom. The liquor in each tower is to be kept separate, in order that the contents of any one may be passed through either of the others, and delivered again into the same cistern after having become intermixed. To this end there is a cross spout v r v 2 v 3 , with plug-holes through which the liquor may be conducted into either of the four-length spouts Wx w 2 w 3 w 4 , each of which communi¬ cates with one of the four wooden cisterns. If a cistern is to be thrown out of opera¬ tion for the purpose of emptying it, re¬ charging it, or otherwise, the tap on its pipe must be turned off. ! 352 PURE FERTILIZERS . When the liquors have reached 12 0 to 15 0 Twaddle, they are to be conducted thence into lead or copper vessels through branch pipes fitted with a tap and connecting severally with the delivery-pipe of the pumps. Here the sulphite-phosphate solution is boiled un¬ til sulphurous acid gas ceases to escape,—an operation that will consume about six to ten hours. While the excess of sulphurous acid is passing off with aqueous vapour, the sul¬ phite-phosphate precipitates. The solution contained five equivalents of sulphurous acid to one of tri-phosphate of lime, and the solid product holds one equiva¬ lent ; therefore, four-fifths of this gas escapes, and must be reclaimed. For this purpose, the boiling vessel is fitted with a cover which connects with a cooling worm so arranged as to allow the condensed water to return to the vessel and the escaping gas to pass into the condensing tower ; for, in open vats, the concentration beyond 15 0 Twaddle wastes both time and sulphurous acid. The sulphite-phosphate settles readily as it forms, and at the end of the boiling is to be collected on a drainer, pressed and dried. SULPHITE OF TRI-PHOSPHATE . 353 It is then ready for market, and has the form of a clean white powder, which neither dirties, tarnishes, nor corrodes, and is, more¬ over, harmless to the taste and touch. Its Disinfecting and Fertilizing Properties. This product is both an effective fertilizer and potent disinfectant. Its insolubility in water and fixedness in air heretofore noted, % would seem to conflict with such a character; but it happens, fortunately for these pur¬ poses, that this stability refers to the action of pure air; for, in a foul atmosphere, the sulphite-phosphate changes gradually into di-phosphate and sulphate of lime, and by this chemical alteration the air is simultane¬ ously disinfected. The more the air is viti¬ ated and the warmer the temperature, the greater will be the energy and rapidity of this reaction. An ounce or two of the pow¬ der distributed in the holds of ships and on the floors of stables, will remove in a few hours the disagreeable odour peculiar to those places, as well as arrest the escape of ammonia; and a daily renewal of this appli¬ cation will keep them sweet permanently. 354 PURE FERTILIZERS. In hospital wards and the chambers of the sick, it is a most useful purifying agent. Animal matter, even if putrid, loses its offensive taint when dusted with the powder or kept in its neighbourhood. Access of air renders its action more decided. The sul¬ phite is always oxidized in these changes, and gives very often an ozone reaction. It is of special value to the farmer for maintaining a pure atmosphere in his stables, piggeries, etc., and, at the same time, for preventing any waste of the ammoniacal emanations from the decomposing dung. Dr. J. Dreschfeld, of Manchester, has re¬ ported a series of careful experiments with this powder as a disinfectant and deodorizer. The results obtained by him were most favourable, even in comparison with those given by well-known rival substances, which were tested at the same time. The oxidation of the sulphite-phosphate takes place when it is sown in the soil, and the decomposition may be expressed by the following formula:— 3CaO, POs, SO 2 , 2HO + O = 2CaO, PO 5 , HO + CaO, S 0 3 , 2HO. SULPHITE OF TRI-PHOSPHATE . 355 The chemical properties of the di- or neutral - phosphate thus formed have been explained already in Chapter hi ; but it has a characteristic energy in fertilizing which must be re-stated here, as it was determined by actual experiment. A portion of the sulphite-product,—say a layer of one inch thickness,—was buried in a stiff' clay soil under a loose cover of the latter. This soil was tested previously for lime and phosphoric acid, by boiling it with hydrochloric acid ; but it did not show any traces of either. After two months—July and August—the sulphite-phosphate was ex¬ humed with care to keep it free of any of the soil, and finally examined. All sulphite had disappeared, and the modified powder was found to consist of— Sulphuric acid - - i 8'59 P er cen t- Phosphoric acid - - 24 58 „ Lime - - - 33‘66 „ In the original substance there were 34 8 per cent, of phosphoric acid for i5'8 per cent, of sulphuric acid; and if no change, or rather assimilation, had taken place, the buried A a 2 / PURE FERTILIZERS. phosphate should have contained 14 per cent, of sulphurous acid for 24*58 per cent, of phosphoric acid: whereas, the analysis shows i 8*59 per cent, of S 0 3 , or an excess of 41 per cent. This excess proves that the moisture of the soil dissolved the newly-formed di¬ phosphate at a quicker rate than that at which it took up the sulphate of lime. In employing the sulphite-phosphate as a fertilizer, it is expedient to mix it with other manurial matters, and more particularly those of organic nature, as its solubility in the soil is thus greatly promoted. The commercial article contains phosphoric acid in proportion equivalent to 70 per cent, of tri-phosphate of lime. Chemical Analysis. The method of analysis is free from diffi¬ culties, and comprises the following steps and manipulations :— 1. Weigh one gramme on a counter¬ balanced watch-glass, and dry in an air- chamber at 248° to 284° Fahrenheit. The loss of weight represents moisture. 2. Take a fresh quantity of one gramme, SULPHITE OF TRI-PHOSPHATE. 357 place it in a glass flask of about 150 c. c. capacity, add boiling- dilute hydrochloric acid, cover the mouth with a funnel, and boil rapidly until all the sulphurous acid is ex¬ pelled. If there should be any insoluble residue it is to be collected on a filter, dried, ignited, and weighed. The filtrate is to be treated, now, with solution of chloride of barium, and the precipitate thus thrown down is to be filtered off and determined. Its amount corresponds with the quantity of sulphuric acid contained in the substance ; for ordinary precaution will prevent any in¬ crease through the oxidation of some of the sulphurous acid during the manipulation. 3. Weigh another gramme of the sulphite- phosphate powder, place it in a beaker glass with some water, and treat it, drop by drop, with a standard solution of iodine. At first, the colour of the iodine disappears rapidly, and the powder loses volume by degrees, until only a few grains remain. From about this point, the decoloration of the iodine liquor proceeds very slowly; but the addition of a few drops of hydrochloric acid will hasten the action to immediate completion. 353 PURE FERTILIZERS. This small quantity of acid has no influence on the result. From the measure of iodine solution consumed, the quantity of sulphur¬ ous acid is to be deduced by calculation. 4. Another fresh gramme of the powder is to be dissolved in a little hydrochloric acid and water, then heated until all the sulphur¬ ous acid is expelled, next neutralized exactly with ammonia, and mixed finally with acet¬ ate of soda. If iron is present it falls now as phosphate, and must be filtered off. The filtrate is to be dosed with oxalate of soda, which precipitates the lime as oxalate in a granular form, and easy to be filtered ; but the whole should stand twelve hours pre¬ vious to filtration. The latter operation is rapid when the liquor is hot at the time of adding the oxalate. 5. From the filtrate, magnesia is to be precipitated by the addition of a large excess of ammonia; and it carries down at the same time some of the phosphoric acid. 6. and lastly. The residual phosphoric acid is to be precipitated from the preceding magnesia filtrate by the addition of an am- moniacal solution of sulphate of magnesia. SULPHITE OF TRI-PHOSPHATE . 359 The following analytical table shows the composition, thus determined, of the several samples of sulphite-phosphate powder noted in the table at p. 341 :— Constituents. I 2 3 4 5 6 Sulphurous acid - I5-58 15-69 1414 1 8*oo 14*440 21-139 Sulphuric acid 0-23 0-84 4-46 274 I-I92 1-704 Phosphoric acid - 34 * 8 o 33*87 31-22 28-69 34'2r5 36547 Lime - 39 89 4076 4023 40 22 40-925 42*313 Magnesia — — trace 0'2I trace 1-184 Sand - — — 046 0 66 — — Water, accidental ,, constitutional o'66 9 08 | 9*24 9-46 1000 9-228 7*ii3 Total IOO ' 2 \ 100 00 100-00 10052 100 -oo 100*00 According to the formula 3CaO, P 0 5 , S 0 2 , 2IIO, the calculated composition of the sul¬ phite-phosphate of lime is,— Sulphurous acid - - . 15-61 Phosphoric acid - - - 34-63 Lime - - - 4098 Water - - 1 GO vj CO 100*00 CHAPTER XVIII. ON THE CHEMICAL TREATMENT OF “ REDONDA GUANO”, “ALTA VELA GUANO”, AND THE MINERAL PHOSPHATES OF ALUMINA AND IRON GENERALLY, FOR THEIR CONVERSION INTO FERTILIZERS. These stony substances, erroneously classi¬ fied in trade as “ Rock Guanos”, were un¬ known until a comparatively recent period. Their obdurate character, in both physical and chemical senses, rendered them at first unsaleable. But time and study improved their character, and now that science has ani¬ mated them with her Promethean fire they enjoy a life of commercial activity. At pre¬ sent, “ Redonda Guano ” and “ Alta Vela Guano ’ are the only representatives in com¬ merce of this class of materials ; but others have been discovered, and will be brought PHOSPHATES OF ALUMINA & IRON. 361 forward, sooner or later, as demand may in¬ crease. Both take their names from the place whence they are brought. The first has its source in Redonda, one of the Leeward Islands, lat. 16 0 55' N., long. 62° 18 W. ; and the second comes from Alta Vela, an island near St. Domingo, in lat. i7°N., long. 17 0 W. The annexed analytical table shows their composition per cent., and also that of seve¬ ral kinds from a source not yet made public, but which has been noted to me by a corre¬ spondent as 11 A. R. B. phosphate rock". Part of the water present is constitutional, and the “Alta Vela Guano” may be con¬ sidered, mineralogically, as Gibbsite. The very much higher ratio of phosphoric acid to the alumina in Redonda Guano and A. R. B., gives them a distinct feature in that respect, and assimilates their formula to that for pyrophosphate of alumina, which is 2AI2, O s , 3 P0 5 , 10IIO (dried at iio°). The instructions about to be noted will apply equally well to all the members of this class. 362 PURE FERTILIZERS . Very little of the “ Redonda” has come forward to this country; but the importation of it into the United States, for the port of Baltimore alone, amounted to 4334 tons during a recent year. The “Alta Vela” is in large supply, owing to the more enter¬ prising management of the business of mining and shipping it. This latter, how¬ ever, although a very useful raw material, is by reason of its lower ratio of phosphoric acid and large proportion of silicious matter, the least valuable of the three; for there is as much acid, labour, and time required to dis¬ solve it as would be necessary for the solu¬ tion of either of the other two. This is an important consideration in making a selec¬ tion for chemical treatment by the processes of this treatise. The precipitate thrown down by milk of lime from the “ mother-liquor ”, which is left by mineral phosphates of lime when treated according to the processes in Chapters ix # * See my patents Nos. 2341, 2344, 2357, of August 6th, 7th, and 8th, 1872. These processes are now leading me to a further improvement which will effect the recovery of PHOSPHATES OF ALUMINA & IRON. 363 and x, is so closely allied in its nature to the Redonda and Alta Vela Guanos, that it may be considered as such for all the pur¬ poses of this treatise. Indeed, it has the great advantage of being rather purer and having a pulpy state, which latter condition renders it soluble instantaneously even in cold and diluted acids. The chemical agents employed in the fol¬ lowing processes are made to do their in¬ tended work in such a manner as not only to add to their original value, but to im¬ prove also the profit on the other mate¬ rials. The proportions of acid given are for the “ Redonda Guano", and must be therefore modified for different phosphates according to the quantity of alumina and iron which they may contain. The larger the propor¬ tion of contained alumina and iron, the greater will be the quantity of acid re¬ quired. the hydrochloric acid, merely by the evaporation of the “ mother-liquor ' to dryness and subsequent ignition of the mass in a suitable furnace. PURE FERTILIZERS. Water - Water of constitution Sand and silica Lime - Magnesia Peroxide of iron Alumina Phosphoric acid Sulphuric acid Chloride of sodium - The quantitative relation per cent, of the alumina to phosphoric acid is as follows :— Phosphoric acid Alumina - or Alumina - Phosphoric acid “A. B. R.” Redonda. Alta Vela. 43-88 I OO'OO 49 ' 9 1 I OO'OO 7 I '20 100-00 “ A. B. R.” Redonda. Alta Vela. 69-50 30-50 67-36 32-64 58-41 41-59 Redonda, by Johnson. Alta Vela, by Voclcker. “A. B. R.” Average. 24-67 4-19 22-55 — I 2'99 — 1-84 27-19 T 95 •56 — — traces — — 6-60 2-79 7-14 21-28 21-98 18-54 43 ' 9 T 00 O CO G\ 42-23 traces — i ‘35 traces — — I OO’OO 100-00 I00-70 PHOSPHATES OF ALUMINA & IRON. 365 To carry out the processes in connection with this mineral, the first step is to reduce it to fine powder by any of the means usually adopted or prescribed in this work. The next is to charge the vat with the necessary quantity of hydrochloric acid of specific gravity 1170. The construction and arrange¬ ment of the vat, and other necessary appara¬ tus, are shown by Plates 26 and 27. The vats are to be mounted upon a brick¬ work support, twelve inches high from the ground, as shown by b, which support must be covered with a flag-stone top c, forming the bottom of the vats a a a. Surrounding the vats and built up to their height, is a brick-work enclosure d, forming a hot-air chamber e, of six inches diameter through¬ out. As supports alike for the chamber and the stone walls of the vats, there should be brick pillars or abutments f f at the corners of the joints and the centres of each vat. The brick enclosure is to be capped with a smooth stone laid very level, and kept tightly in place by iron bolts fixed tightly into the brick-work by means of lead. These bolts are to be screw-cut at the ends 3 66 PURE FERTILIZERS. to the length of two inches, and must pro¬ ject above the stone-work, as shown by^^*. The division stones of the vats are to be cut down at the centre of the top side, so as to form a passage-way eight inches square for accidental overflow from vat to vat, in cases of uprising of the contents from violent chemical action. Each vat is to be provided with a manhole i, projecting through the brick-work, for the removal of its more solid contents or for cleansing it. Also, on the bottom, but in the front of the vat, there is to be a drain- hole j, of four inches diameter, anci fitted with a movable plug of caoutchouc in coni¬ cal form, as shown by fig. 11. Fig. ii. Behind this drain-hole, and in an angular position, resting upon the interior bottom of the vat, is to be a stone covering pierced PHOSPHATES OF ALUMINA & IRON. 367 with many holes and laid over with straw at the commencement of the operation, when it is intended, subsequently, to drain the liquid downwards from the solid portion of the charge. Holes and plugs similar to those just mentioned, but of only two inches diameter, are to be placed along the whole height of each vat, at intervals of twelve inches apart, as shown by l l. These must be fitted by means of iron tubes projecting outwards through the brick-work, and fixed to the stone of the vats by means of a collar and molten lead or sulphur. The cover of each vat is to be in two pieces, the rear part m being fixed. The other portion is movable, but can be fixed as required by means of the bolts and their nuts. The fixed part of this cover must be of cast-iron, an inch thick, so as to be suffi¬ ciently strong to bear the weight of the work¬ man who may be charging the vat. Its under or inner side is to be covered with a thick layer of the pitchy matter from the stearic candle factories, as a protection against the corrosive action of the vapours evolved. 3 68 PURE FERTILIZERS. In this piece the box and passage-way for the stirrer o are to be arranged. All parts of this stirrer are to be of very hard wood or of wrought iron, with arrangement for lifting it out when not in operation, as shown at Plate 26, by means of the chains z z going over a pully at the back. Towards the edge and near the corner, there is to be fitted a tube q, leading to the fire hearth of the factory chimney for conveying away the noxious gases as they may arise in the vat during the operation. These pipes may connect with one larger pipe r, fixed at the back of the vats and leading into the fire. In the opposite corner, about a foot to¬ wards the centre, there must be a hole of six inches diameter for the entry of the acid or the powdered mineral into the vat, as may be required. This should be fitted with a hop¬ per of hard stone r', about twelve inches diameter and six inches deep. The rim should be strong and flat to form a support for the inverted carboys in the act of their being emptied. A simple hopper arrangement, as described, will answer only when the vat is to be PHOSPHATES OF ALUMINA & IRON. 369 charged first with acid and the mineral is to be added afterwards in dry powder. On the other hand, if the powdered mine¬ ral is to be moistened with water previously to falling into the vat, then the hopper must be replaced by the mixer already described at p. 116. To render the vat suitable for general service, the cover should be fitted with both a hopper and mixer. The front part of the cover may be of wrought iron plate, a quarter of an inch thick or less, and pierced around the edge with holes g g for the passage of the bolts gg. It must be lined around the inner edge with an india-rubber washer, as well as coated with stearic pitch on its inner surface, so as to form a tight joint and retain an un¬ corroded surface. The bolts g g and the holes g g allow the cover to be removed and put in place, at will, by the supplementary aid of the screw-nuts gg". It should be remarked that, in default of the cement already noted, the best hydraulic cement is the proper material for making the joints of the vats; but, to further protect B B 370 PURE FERTILIZERS. them against the action of the acid contents, they should be covered over with marine glue, or better, with the pitchy residue ob¬ tained in the distillation of fats (mixed with a little shellac), and to be bought cheaply at the stearic candle manufactories. The mode of preparing this latter is described in Chap¬ ter XXVI. The vats are to be kept warm, when in operation, by means of steam circulating through the iron tubes s s, arranged in the brick chamber. These tubes should be covered with stearic pitch, or some equally good coating, to protect them against the action of acid vapours. In the rear of the vats there must be a wooden platform apparatus t, Plate 27, to facilitate the charging of the vats with the acid. That it may be moved readily from vat to vat, it is mounted on iron wheels. To better explain, however, the operation of the lift, the manner of charging the vats with acid is as follows. The cage w of the lift being lowered to the level of the ground, full carboys are then placed on the trolley or bogey t t, and the whole elevated by means MOR FIT on T R. L_ Fig. I. 4 Plate 22 Fig. IV. • -in.il .' desire J for D r I, OF FEET J£ 6 8 i Truhner& C°,60 Paienusti-L kow PHOSPHATES OF ALUMINA & IRON. 371 of the gearing a', until the tops of t are level with the top of the vats. At this point, the rails on w will coincide with similar ones upon a fixed platform running in the rear of the vats a a a. The trolley t is then ad¬ vanced until it is opposite the vat requiring to be charged, and the carboys emptied into it. The empties arc taken down by the return cages. If the powdered mineral is to be dropped into the acid dry, it is brought up from the ground beneath in the cups v on the endless band u of the elevator, which is carried by strong wooden supports b'. After being emptied from the cups into the hoppers c c , it passes into the vats through the adjustable gutters dd resting one end on the hopper r and the other on supports e r spe¬ cially arranged for the purpose. When the powder is to be moistened with water or acid previously to falling into the vat, it must pass through the mixer instead of the hopper. The proportion of acid will depend upon the quantity and composition of the mineral to be treated. In this instance of “ Redonda 15 B 2 372 PURE FERTILIZERS. Guano”, as a standard, for every ton of that material about half a ton of hydrochloric acid 1*170, or its equivalent in weaker acid, must be taken. The acid is to be raised in car¬ boys and emptied into the vats by means of the lift, as already described in Chapter v, or it can be sent up from a reservoir in the ground by means of a monte-jus, Plate 10, Chapter v. Care must be observed in this manipulation to prevent as much as possible the escape of acid fumes into the factory, for the vats have been designed to promote con¬ venience and comfort in this respect. When the requisite charge of acid is in the vat, the powdered mineral must be mounted by the elevator, and dropped into it from the cups during constant stirring. The manner of gearing this latter for motion is shown at Plate 26. All the mineral having entered the vat, and the mixing being completed, the whole is to be left for twelve hours. At the end of this time about cwt. of commercial oil of vitriol of specific 1*846, or 9^ cwt. of brown oil of vitriol of specific gravity 1*700, are to be added in a thin stream and during con- PHOSPHATES OF ALUMINA & IRON 373 stant stirring. When the acids are added in the succession just named, there is little or no intumescence. Moreover, all hardening of the mass is prevented by adding the sul¬ phuric acid last, and after the preliminary action of the hydrochloric acid. To effect the prompt and perfect solution of the mineral in any other manner was found by me to be very difficult on a practi¬ cal scale. As this treatment causes much chemical action and evolution of vapours, there should be frequent halts in adding the acid. When all the acid is in the vat, the stirring is to be stopped for an hour, and then renewed during five minutes. The mass is to be thus roused again and repeatedly by stirring during the succeeding ten to fifteen hours. On the expiration of this interval, the mass will have become a thick syrupy fluid, which is then to be diluted with water, stirred well, and left to repose. The water of dilution should not be more than half the volume of the acid liquor. To save time in effecting the solution of the mineral, steam should be coursing 374 PURE FERTILIZERS. through the tubes which warm the air- chamber of the digestion vat, as heat pro¬ motes the chemical action very sensibly. If there is any insoluble matter in the mineral, it will now fall to the bottom of the vat, and leave a clear liquor above. This supernatant liquor is a sulphuric-hydrochlo¬ ric solution of the aluminium and iron phos¬ phates, together with more or less of the oxides of aluminium and iron which the mineral may have contained. It is to be drawn off clear through the plug-holes into a wooden vat. The construction and arrangement of this vat have been described already at p. 127. The insoluble matters are to be removed through the manhole at the bottom of the digestion vat, and thrown aside as waste after having been washed once or twice with relays of fresh water. If, however, as in the case of “ Redonda Guano”, the insoluble matter does not exceed several per cent., it may remain, and the next operation can go on in the same or digestion vat; and thus very much time, labour, and expense will be economized. PHOSPHATES OF ALUMINA & IRON. 375 The liquor, while still in the digestion vat, or better, after having been drawn off clear into a second vat, is next to be treated, during constant stirring, with quick-lime previously slaked and made into a smooth milk. This neutralizes the sulphuric acid by forming with it hydrated sulphate of lime. Immediately following the addition of the milk of lime, a sufficient quantity of crude gas-liquor is to be poured in during constant stirring, to throw down all the contents of the liquor that can be thus precipitated. All of the hydrochloric acid becomes neutralized and remains in the solution as chloride of ammonia. Much carbonic and bad smelling gases are evolved during the reaction ; and, therefore, the ammoniacal gas-liquor must be added slowly in an open or well-ventilated apartment. When a red litmus paper, dipped into the liquor, may turn blue, it is a proof that enough of gas-liquor has been added. The precipitate which settles, by repose, from the liquor is a greenish-grey-blue pulp, consisting of aluminium and iron oxides and phosphates, with sulphate of lime and some little sulphuret of iron. 376 PURE FERTILIZERS . For ioo tons of “ Redoncia Guano" there will be required 33 tons of oil of vitriol, 50 tons of hydrochloric acid, 20 tons of quick¬ lime, and 300 tons of gas-liquor of 6° Twaddle. The dried product will be, ap¬ proximately, a mixture of 75 tons of gelatin¬ ous phosphates of alumina and iron, 45 tons of hydrated sulphate of lime, and 25 tons of chloride of ammonium, making a total of 145 tons. The precipitation may be effected wholly by gas-liquor, and in such case the precipi¬ tate would be free from lime or its sulphate; but the difficulty is to find a sufficient quan¬ tity of the gas-liquor in any one locality for large and continuous operations. In all cases the precipitate and its liquor are to be drawn off together into a kiln, evaporated to dryness, and reduced to a granular powder by means of Carr’s disin¬ tegrator. As the mass approaches dryness, the heat must not exceed 200° Fahrenheit; otherwise, it will become too hard and gritty. It is then ready for market as a fertilizer. But to make its agricultural appreciation more assured, it should be mixed with ten per cent, of bi- or di-phosphate of lime. PHOSPHATES OF ALUMINA & IRON 377 It is very doubtful, however, whether the phosphates of alumina, even in their tender pulpy state, will ever sustain an active com¬ petition, as fertilizers, with the phosphates of lime, so long as the supply of the latter does not diminish ; for the preparation of the former is expensive, comparatively, and the actual measure of their agricultural effect has yet to be determined. As raw material, however, for the many other useful products explained in Chapter xxi, they are of prime importance, by reason of their abundant supply and moderate price. CHAPTER XIX. THE MINERAL PHOSPHATES OF ALUMINA AND IRON AS RAW MATERIAL FOR THE MANU¬ FACTURE OF ALUM AND OTHER USEFUL PRODUCTS. The sphere of industrial utility pertaining to this class of substances is a very wide one, thanks to the genius and practical skill of those men of science who have given the subject their special consideration. Many and varied are the products which may be evolved from them profitably by proper che¬ mical treatment. The precipitate obtained from the “ mother- liquor ’ of acid solutions of mineral phos¬ phates of lime, which is left by the processes described in Chapters ix and x, having the same nature as the mineral phosphates of alumina and iron, may take the place of the latter advantageously in all the processes ALUM AND PHOSPHORIC ACID. 379 about to be described. Being pulpy and easily soluble, its use will promote economy of plant and facility of manipulations through¬ out. Alum and Crude Phosphoric Acid ', etc ., etc. The pioneer chemist in these relations of the subject is Mr. Peter Spence, of Manches¬ ter, who has published recently a valuable process. It is set forth in the following description :— “ My invention consists in the use of com¬ pounds of alumina and phosphoric acid, such as are at present obtained in the island of Redonda, near Antigua, in the West Indies, and known under the name of Redonda Phos¬ phate, and which contain a variable portion of iron, and of minerals of similar composi¬ tion obtained in other West India islands and other places. These minerals I propose to utilize by the manufacture of alum, and by obtaining phosphoric acid or compounds thereof as by-products for use as manures or fertilizers, and for other purposes, such pro¬ ducts, when free, or comparatively so, from alumina, being rendered valuable agents for 38o PURE PER TILIZERS. those purposes, especially so as manures or fertilizers. The treatment for the aforesaid purposes of the said minerals may be varied in details, but the following is a description of that which I have found to answer. I take the mineral in pieces as it comes to hand and calcine it in kilns similar to those used for lime, exposing it to a red heat by mixing it with coal or coke ; or I take the mineral as obtained, and grind it so that it will pass through a sieve of, say, twenty meshes to the inch ; but I prefer the former plan, as it facilitates the solution of the mine¬ ral substance, and renders a portion of the iron insoluble by oxidation. The mineral having been prepared by these or by similar means, I place it in leaden vessels and add thereto an equal weight of sulphuric acid of specific gravity i*6 if the mineral contain twenty per cent, of alumina, but only three- fifths of its weight if it contain twelve per cent., and in similar proportions for other degrees of richness. I then apply heat, which I prefer to do by blowing steam into the vessel containing the mixture. The mineral dissolves and the specific gravity rises. I now cautiously reduce by w^ater or weak liquors from subsequent parts of the process (especially the washings of the sediment here- ALUM AND PHOSPHORIC ACID. 381 after to be mentioned), constantly boiling until all is dissolved except the insoluble sediment, and the strength of the liquor becomes 9C0 Twaddle or 1*45 specific gravity. I now pass this liquor into a close leaden vessel and dis¬ til into it vapour containing ammonia ob¬ tained from gas ammoniacal liquor subjected to boiling either by fire or steam injected into the said gas-liquor, and the quantity of the said gas-liquor I use is equal to 600 to 900 gallons to each ton of the mineral, according to its richness. When all the ammonia has been distilled into the mineral liquor I allow it to settle for a few hours and then run off all the clear solution (now at a strength or specific gravity of 1*4, or 8o° Twaddle) into lead-coolers, to crystallize alum, as is well understood; and I allow it to remain in these coolers for some days, with frequent stirring, in order to obtain all the alum possible, and which may be purified by re-crystallization, as well known. I find that when the mineral contains twenty per cent, of alumina, I ob¬ tain about one and a half ton of alum from one ton of the said mineral. The mother- liquors having deposited all the alum that can be obtained, are now chiefly a solution of phosphoric acid with a small quantity of sul¬ phate of alumina, iron, and sulphate or phos- 382 PURE FERTILIZERS. phate of ammonia. This liquid may be used directly as a fertilizing agent; but I prefer to take the said mother-liquors direct from the coolers and add to them dry sawdust or other absorbing agent, just sufficient in quantity to absorb all the said liquors, so that none will run from the sawdust. I now take the sub¬ stance and dry it at a low heat, so as not to char the sawdust, and when dry it forms an artificial manure containing phosphoric acid and ammonia in such quantities and condi¬ tion as to make it a valuable fertilizer. In¬ stead of ammonia gas-liquor, used with the mineral solution to produce alum, salts of potash may be used, either alone or in combi¬ nation with ammonia ; of the former, the chloride of potassium of commerce, or, pre¬ ferably, sulphate of potash; as, although chlo¬ ride of potassium will yield a sufficient pro¬ duct of alum, the fertilizer would, from its use, have a tendency to deliquesce, but sul¬ phate of potash will not have that effect. From the above description, it will be seen that, by my invention, I obtain as a by-pro¬ duct, a large quantity of phosphoric acid; and it has been stated how this may be used as a fertilizing agent ; but, independently of that, it may be applied to the purposes of producing phosphorus in the usual manner, or phos- SULPHATE OF ALUMINA. 383 phoric salts of commerce, as phosphate of soda, by adding the required base thereto, extraneous matters in the mother-liquors be¬ ing separated, if desired, by ordinary pro¬ cesses of precipitation and crystallization. The operations for making alum, above de¬ scribed, leave a sediment of insoluble matters which may be washed, and the washings used for the reduction of the dissolved mineral, as above alluded to. Having thus described and ascertained the nature of my said inven¬ tion, and the manner in which it is to be per¬ formed, I desire it to be understood that I claim the use of such mineral phosphates as aforesaid, for the combined purposes of the production of alum and manures, and other substances, as mentioned.” Sulphate of Alumina. “Redonda Guano”, and other natural phos¬ phates of alumina, have been made the basis for the preparation of sulphate of alumina and phosphate salts, according to the following process by John Berger Spence and Peter Dunn:— “ Our invention consists in a decomposi¬ tion of natural phosphates of alumina, where- 3*4 PURE FERTILIZERS . by we obtain sulphate of alumina and also phosphoric acid or compounds thereof, which afford valuable fertilizing agents, or may be used for other known purposes. “ In carrying out our process, we take the natural phosphate of alumina, and, having broken it (if necessary) into small pieces, place it in a leaden or other suitable vessel and pour sulphuric acid thereon in the proportions of about twelve hundred-weight of sulphuric acid to one ton of phosphate of alumina; but the proportion of sulphuric acid may be in¬ creased or decreased, according to the per¬ centage of alumina contained in the phosphate of alumina. After digestion for a few hours the result will be the formation of sulphate of alumina and phosphoric acid ; and, in order to separate the alumina from the acid, we in¬ troduce ammoniacal water or the products distilled therefrom until the alumina is preci¬ pitated. This substance can then be obtained by running off the supernatant liquor from the precipitated alumina. We then add sul¬ phuric acid to the precipitate in about equal proportions, when sulphate of alumina will be formed. The phosphoric acid thus set free from the alumina may be collected and obtained or combined with any desired base, so as to form salts by any of the known pro¬ cesses for so doing - . PHOSPHATES OF ALUMINA , ETC. 385 “ The above process may be varied by sub¬ stituting alkaline sulphates or sulphurous acid for the sulphuric acid, but in this case sulphite of alumina will be produced, which will, however, be converted into the sulphate by exposure to air, so that it may take up the required proportion of oxygen. “ The process may be varied by the use of soda or potash or their carbonates in the place of ammonia.” Phosphate of Ammonia and Phosphates of Lime. A further contribution to the practical chemistry of the natural phosphates of alu¬ mina has been made recently by John Berger Spence and Peter Dunn, in the following specification :— “Our invention refers to certain methods of treating products arising from the practice of an invention, for which Letters Patent were granted to Peter Spence, dated Ninth June, One thousand eight hundred and seventy, No. 1676. “According to that invention, the substance known by the name Redonda Phosphate and other phosphates of alumina, are used for c c 386 PURE FERTILIZERS. the manufacture of alum, and this having been crystallized there remains a mother- liquor, consisting chiefly of a solution of phosphoric acid ; and our invention refers to certain methods of treating this mother- liquor, in order to obtain substances which may be conveniently and advantageously em¬ ployed as manure. “According to our first process, we take the said mother-liquors and cause them to be absorbed by sawdust or other convenient substance, which will, in like manner, hold them mechanically ; and we then place this material in purifiers of gas-works, or in simi¬ lar apparatus, so that the impure gas shall pass through, or in contact with it, as is now the case when gas is purified by other sub¬ stances, and this operation is continued until all the acid in the said mother-liquor has been neutralized by the ammonia compounds which have existed in the gas. The resulting compound being chiefly phosphate of ammo¬ nia mixed mechanically with the sawdust, is available as a valuable manure, or the phos¬ phate of ammonia may be dissolved out and thus separated from the sawdust. “According to a second process, we distil ammonia compounds from gas ammoniacal water into the said mother-liquor, by which PHOSPHATE OF AMMONIA , ETC. 387 means we obtain a substance which, as be¬ fore, is chiefly phosphate of ammonia. “According to a third mode of treating the said mother-liquors, we use them instead of sulphuric acid, or to replace a part thereof, in the manufacture of superphosphate of lime from the ordinary tri-basic phosphate of lime of commerce; and, by using, say, one-half of such mother-liquors, together with one-half the usual quantity of sulphuric acid, we ob¬ tain a manure much richer in soluble phos¬ phate of lime than by the usual method. “Fourthly. We use the said mother-liquors to produce therefrom precipitated or insoluble phosphate of lime, by adding to such liquors as much lime or carbonate of lime as will produce neutrality, which condition will easily be found by practice, and we thus obtain a compound of considerable value as a manure. “ Fifthly. We obtain from the said mother- liquors a soluble, or partly soluble, phosphate of lime, by calculating the quantity of lime in proportion to the phosphoric acid contained in the solution, so that the result may be a mono-basic phosphate of lime. As a guide for this operation, we may state that when the liquors, after the alum is extracted, are of the specific gravity of 1*4 or 8o u Twaddle, we find that the quantity of dry slacked lime or c c 2 3 88 PURE FERTILIZERS. hydrate of lime required is i lb. for every 15 lbs. of the said mother-liquors ; and we add the said quantity of lime after having boiled the liquors to such an additional strength as will produce a friable compound in suitable condition to be used alone or mixed with other manures. The extent to which the liquors are to be boiled clown to afford this condition will readily be ascer¬ tained by practice. By this process, we find that a considerable portion of the phosphoric acid is combined with the lime in the state of mono-basic or soluble phosphate of lime, which is the more valuble condition as a manure. “ Having thus described and ascertained the nature of our said invention and the man¬ ner in which the same is to be performed, we desire it to be understood that we claim the use of the mother-liquors resulting from the manufacture of alum according to the patented process of the said Peter Spence aforesaid, for the production of manure by the processes substantially above described, that is to say,— “ Firstly. By submitting the said mother- liquors to illuminating gas during the purifi¬ cation thereof. “ Secondly. By distilling gas ammoniacal water into them. TOWNSEND'S PROCESS . 389 “ Thirdly. By using them instead of the sulphuric acid or a portion thereof employed in the manufacture of superphosphate of lime from the ordinary tri-basic phosphate of lime. “ Fourthly. By adding lime or carbonate of lime thereto in such manner as to produce precipitated or insoluble phosphate of lime, “ Fifthly. By adding lime in such quantity as to produce a soluble or mono-basic phos¬ phate of lime.” Townsend's Process . Mr. Joseph Townsend, of Glasgow, has patented, quite recently, a process for the chemical treatment of mineral phosphates of alumina, which is worthy of the best con¬ sideration, as it embraces some novel and very valuable ideas. I have not yet determined its practical economy ; but having previously worked in the same direction, there is little doubt, in my mind, that any defect in that respect, if one may possibly exist, would soon disappear through the improving effect of practical experiment. The author thus describes his invention :— “This method has for its object to utilize 390 PURE FERTILIZERS. and obtain valuable products from phos¬ phates which contain alumina, and which are obtainable, or similar to what are obtainable, from Redonda, in the West Indies. “And in order that the method may be properly understood, I shall proceed to parti¬ cularly describe the various processes com¬ prised in it as applied to a phosphate con¬ taining about 40 per centum of phosphoric acid and 20 per centum of alumina, and it must be understood that when the material operated upon contains other proportions of the ingredients the processes are to be cor¬ respondingly modified. “ By my first process, 50 lbs. of soda or 75 lbs. of potash, are mixed with the phos¬ phate, and heat is by preference applied either by fusion or boiling in about 50 gallons of water. After settling, the supernatant liquor is run off, or it is filtered, and the phosphate of soda or of potash that is formed is sepa¬ rated by crystallizing, or by concentrating and depositing, when the remaining liquor will consist principally of aluminate of soda or of potash. When it is aluminate of potash that is wanted, aluminate of soda may be first formed as described, and the aluminate of potash be subsequently obtained by double decomposition on adding chloride of potas- TOWNSEND'S PROCESS . 39 i sium or carbonate of potash. If alumina is wanted, its deposition from the aluminate of soda or of potash is obtained by injecting or otherwise applying carbonic acid. “ By my second process, 12 lbs. of soda or 18 lbs. of potash and 47 lbs. of lime are added to the phosphate, and by preference heat is applied by boiling, whereby aluminate of soda or potash and phosphate of lime are formed, the former in solution, and the latter as a precipitate. “ By my third process, 47 lbs. of lime are added to the phosphate, and by preference heat is applied by boiling, whereby there is formed a mixture of alumina and phosphate of lime, which can be used as a manure or fertilizer. “ This mode of utilizing the Redonda or similar phosphates containing alumina by adding lime to form a phosphate of lime usable as a fertilizer, is obviously also appli¬ cable, although the alumina, or more or less of it, may have been separated before adding the lime. Thus, if the aluminous phosphate is first treated with sulphuric acid and sul¬ phate of ammonia or of potash, and the alum thereby formed separated, phosphoric acid is set free, and, remaining in the mother-liquors, may have the lime, or, what will in this case PURE FERTILIZERS. 39^ answer as well, its carbonate added to it, and so be converted into phosphate of lime; or alum may be obtained by adding chloride of potassium and sulphate of magnesia, and after it is separated by well-known means the remaining liquors will contain phosphoric acid, which may be precipitated as phosphate of lime, by adding lime or its carbonate, as before. “ By my fourth process, 58 lbs. of lime are added, and cause the formation of a mixture of phosphate and aluminate of lime, also usable as a manure or fertilizer; or aluminate of soda or of potash may be obtained from the mixture by adding 20 lbs. carbonate of soda, or 26 lbs. carbonate of potash, leaving carbonate and phosphate of lime usable as a manure or fertilizer. If phosphoric acid is wanted, nitric, sulphuric, or hydrochloric acid is added to the phosphate of soda or of potash obtained by the process hereinbefore described as my first, which sets free the phosphoric acid, forming at the same time the nitrate, sulphate, or chloride of the alkali of the phosphate, which salt can be separated by well-known means ; or a phosphate of an earth can be obtained by adding to the phos¬ phate of soda or of potash, lime, magnesia, baryta, or strontia, or a soluble salt of any of these earths.” CHAPTER XX. -- THE PHOSPHATES OF ALUMINA AND IRON AS RAW MATERIAL FOR DEFECATING TOWN- SEWAGE. The utilization of town-sewage is that para¬ mount problem of hygiene and economics which finds a practical solution more nearly complete in the use of alumina and iron phosphates and oxides than can be accom¬ plished otherwise. The sewage of towns is a rich fertilizing material, by reason of the nitrogenous or¬ ganic matter which it contains ; but the putrefactive tendency of the latter invests it with unwholesome influences as to the at¬ mosphere and vegetation. It is, at the same time, very bulky, on account of its enormous volume of water of dilution. # In dealing o * The quantity of sewage entering the Thames from 394 PURE FERTILIZERS. with it, consequently, there must be such an adjustment of the public and private interests involved, as will secure the entire separation, in profitable form, of all the foreign matters, whether dissolved or suspended, as well as the deliverance of the effluent water in pota¬ ble condition for mixing with any stream, and by means which will not disturb social convenience or comfort. In other words, the means which are em¬ ployed must be free from engineering diffi¬ culties, very simple as to manipulation, and always under control as to economical supply and management. Therefore, the defecating agent must be from an inexhaustible source near at hand, and such a pliable material that it can be made to do its work over and over again, indefinitely, after having, at each suc¬ cessive operation, previously given up to commerce, agriculture, or the arts, that more valuable portion which is not needed for de- London and its suburbs is computed to be 31,650,000,000 gallons annually; and the proportion of solid constituents varies from to 17 ounces per ton of sewage, according to locality. This includes both the suspended matters and those in solution. MORFI1 on the Ma rtu/mture of Fertilizers. Pl ate ‘23 Draining Vats PERSPECTIVE VIEW 0 7 SCALE -i- o L 9 /ret Specially designed for S r Mo-fit's Work on. Fertilizer s. Vincent Brooks, I) sty VSoii, Lith. Triibrier d C°,6Q. Paternoster Fov DEFECATION OF TOWN-SEWAGE. 395 fecation. However rapidly progressive may be the daily consumption of such an agent, this constant reproduction of supply will fully keep pace with every demand upon it. By adopting Forbes’s process as the initial purifying operation, a long stride may be made towards the accomplishment of the purposes in view. The alumina and iron salts are well known to have the property, in characteristic degree, of separating organic, sulphuretted, and infectious matters from liquors ; and it is only necessary, as Forbes prescribes in the case of sewage, to employ a solution of any mineral phosphate, like “Alta Vela" and “ Redonda Guanos”, in either sul¬ phuric or hydrochloric acid. This solution is made to flow as a thread-like stream into the sewage, and so that it may meet, concurrently, a thin stream of milk of lime. At the moment of contact, the lime neutral¬ izes the acid which holds the alumina and iron oxides or phosphates in solution, and, consequently, these latter, in precipitating as a solid, carry down all the suspended and some of the soluble matters of the sewage. The precipitate is a valuable mixed matter 39 6 PURE FERTILIZERS. which will receive consideration directly; and the clear fluid portion or effluent water retains, of its original impurities, only a portion of saline ammonia and other salts in solution. These must be removed, in great degree at least, by further treatment; and the best course in my judgment is to let the effluent water flow from the precipitate upon beds of peat charcoal. By infiltration through these media it becomes quite or nearly sweet and pure; for the chemico-mechanical pro¬ perties of peat charcoal are peculiarly great for destroying the septicity of liquors and removing any tendency to unwholesomeness. Moreover the peat charcoal accomplishes this result by increasing its own commercial value, as a fertilizer, in degree nearly proportional to the amount of saline impurities which was contained in the infiltrating effluent water. Though I have not yet determined the question, actually, it is my impression that the capacity of the charcoal for abstracting certain saline matters from the effluent sewage waters is so great, that it would serve for a long protracted period as a filter¬ ing medium. DEFECATION OE TOWN-SEWAGE . 39 7 In other words, the effluent water may be passed through peat charcoal in oft repeated fresh currents without producing saturation ; and that when saturated with saline matter it may be revived by calcination in suitable vessels to do its original service over and over again an indefinite number of times. Its ammonia being given off; at the same operation could be reclaimed by simple con¬ densation and sent to market in pure solid form. Such a profitable mode of making the charcoal a self sustaining material on the spot would endow the enterprise of purifying and utilizing sewage with both scientific and practical perfection. No sewage is fit for any process of filtration or irrigation until the sludge has been pre¬ viously separated ; and the mass of antiseptic filtering medium required for the final treat¬ ment or infiltration of the effluent water, will be very materially lessened by using a chemical agent as described for purifying the liquor, in degree at least, while promoting the deposition of the sludge. It is always preferable to use hydrochloric 39§ PURE FERTILIZERS. acid as the solvent for the mineral phosphate in this connection, because sulphuric solutions cause the formation of sulphate of lime, which renders the sewage precipitate unprofitably bulky and weighty. I propose, however, to make the sewage enterprise independent of all natural phos¬ phates of alumina; and, indeed, to liberate it from the contingencies of a precarious supply of any defecating material. To this end only the quantity which may be necessary for the treatment of the first batch of sewage will be required ; and for the purpose, I replace the natural phosphate by a new artifical material which is, in fact, a waste product at present ; being the “ mother-water ” as eliminated by my processes for the precipitation of pure phosphates of lime from hydrochloric solu¬ tions of mineral phosphates of lime described in Chapters ix and x. It consists of alumina, phosphate of alu¬ mina, oxide of iron, and phosphate of iron, in the state of liquor ; and is, qualitatively, a counterpart of the acid solution of Alta Vela or Redonda Guano, but in superior degree as to the quantitative relation of the best consti- D EFECA EION OF TO WN-SEIVA GF. 399 tuents. Being, moreover, a by-product, it saves all the expense and trouble of the acid and manipulation involved in the use of Alta Vela and Redonda Guano ; is always very cheap, and in abundant supply on the spot, and releases the sewage-purification enter¬ prises from all dependence upon the con¬ tingencies incident to an imported material. Being a hydrochloric solution, the sewage precipitate produced by its means has the maximum degree of concentration, as will be seen by comparing the results in the analy¬ tical table given over leaf. The organic matter contains nitrogen in proportion equivalent to to 2 per cent, of ammonia. The figures of the following table prove that sewage precipitate under most favourable conditions cannot contain more than 5 to 10 per cent, of phosphoric acid and ij to 2 per cent, of ammonia. These are the only components of agricultural value, except the organic matters. The ammonia gives a money expression to it of 24s. to 32s. per ton ; and the phosphoric acid associate being combined with alumina and iron is worth only 10s. to 15s., so that the total value 400 PURE FERTILIZERS . COMPONENTS. Sewage pre¬ cipitate ob¬ tained by means of a sulphuric solu¬ tion of Alta Vela Guano. Morfit and B. IV. Gerland. Sewage pre¬ cipitate ob¬ tained by means of the “ mother- water”. Morfit. Moisture 8*6o 7*20 Sand and silica - 38-04 36-49 Organic matter, insoluble - 8'3S 7*l8 Organic matter, soluble in water - 2‘04 2*15 Organic matter, soluble in hy- ) drochloric acid - 3 9*37 9*14 Alkaline and magnesian chlo- ) •90 1*25 rides and sulphates - I Sulphate of lime - 3'iS — Carbonate of lime I2-84 | 570 Lime, combined with organic acids 3-29 Carbonate of magnesia - - ro/ — Peroxide of iron 5'35 Alumina 4*66 V 15-26 30*09 Phosphoric acid 5' 2 5 3 Total - 102*94 99*20 would be only 34s. to 47s. per ton. Hence, it follows that the use of Redonda and Alta Vela Guanos, in the defecation of sewage, becomes a profligate application of them when the precipitate is to be dried and sold as a fertilizer. Greater manurial value would DEFECATION OF TOWN-SEWAGE. 401 be obtained at less cost by the substitution of pure phosphate of lime. The mineral phosphates, as well as the “ mother-water", must, therefore, be emanci¬ pated in more profitable forms, after having done their work of purifying the sewage ; and the practical methods for widening their sphere of industrial utility will be the sub¬ ject of the following chapter. At the same time, it should be remarked that the organic matters, silica, and chemico-mechanical tem¬ perament generally, of the sewage precipitate, render it a superior special manure for clay soils. i) i) CHAPTER XXI. —r-~ THE PROFITABLE UTILIZATION OF THE PHOS- PHAT-ALUMINA PRECIPITATE FROM SEW¬ AGE, AS RAW MATERIAL FOR VARIOUS PRODUCTS. The information about to be set forth refers to the profitable utilization, for sundry pur¬ poses, of the alumina-ferruginous precipitate that is formed, by means of lime acting on solutions of aluminium and iron oxides and phosphates in connection with sewage, for the defecation and deodorization of the latter. It is indifferent whether these are specially prepared solutions of a natural phosphate of alumina and iron in sulphuric acid, like the “Alta Vela Guano”; or the “ mother-liquor ”, which is left when phosphate of lime is separated in a pure state from hydrochloric solutions of mineral phosphate of lime, by the skilfully adjusted addition of lime, chalk, PRECIPITATE FROM SEWAGE . 403 whiting - , oxide of aluminium, oxide of iron, phosphate of alumina, or phosphate of iron as the precipitant. The precipitate thus formed consists of the organic matter which was suspended in the sewage, together with phosphate of alumina, phosphate of iron, oxide of aluminium, oxide of iron, sulphate of lime, and some excess of the lime-precipitant; provided the defecating agent or liquor was a solution of “Alta Vela” or kindred mineral in sulphuric acid. But, if the hydrochloric “ mother-liquor” from mineral phosphate of lime should be substituted for the sulphuric defecating liquor, then the precipitate will not contain any sulphate of lime. Furthermore, the aluminium and iron compounds may be precipitated from the “ mother-liquor" by means of milk of lime, without the intermediation of sewage . But, in such instances, the precipitate will be free from both sulphate of lime and organic matter; that is, the aluminium and iron compounds will be thrown down pure. In each case, however, the precipitate has a pulpy condition, most easily acted upon by D D 2 404 PURE FERTILIZERS . dilute acids and other chemical agents, and is free from all associates which are obstruc¬ tive to the purposes in view. These proper¬ ties give it, therefore, a commercial value very much greater than that of the original mineral whence it was derived, even though the expense of thus improving it may be taken into calculation. Indeed, it is their application to sewage in the first instance, that gives to the mineral phosphates of alu¬ mina and iron their maximum of commercial appreciation. The precipitate formed with sewage is a good manure, qualitatively, by reason of the nitrogen and phosphates which it contains ; —all of these being in potential conditions for promoting vegetation. This effect can be realised, however, only by sowing the pre¬ cipitate in its hydrated state ; for, when dried into a hard powder by heat above 212° Fahrenheit, for greater economy and con¬ venience of transportation, it loses much of the sensitiveness of its chemical tempera¬ ment, and becomes less quickly assimilable by the growing crops. This fact, and the additional circumstance PRECIPITATE FROM SEWAGE. 405 that the alumina and phosphate of alumina which it contains may be turned to better account for various technical purposes, prove, however, that the restriction of this precipi¬ tate to agricultural service, is a waste of its capacity for a wider range of utility. There need not be any sacrifice in this wider application of the nitrogenous organic con¬ tents. The economic applications which I pro¬ pose to give this new material, and the modes of treating it for them severally, are as follows :— Firstly. For the Reclamation of its Nitrogenous Matter as Material for the Manufac¬ ture of Ammonia Salts. The precipitate may be made to give up all its insoluble* organic matter for indepen- * The whole of the nitrogen could be reclaimed as ammonia salt by combustion of the dried precipitate with soda lime, as suggested at pages 51-53- The solid residue would still be a good material, both for the purposes named in page 40S, and for the products noted in this chapter. 406 P URE PER TIL JEERS. dent use as an ammonia material. It is only necessary to draw off the effluent (sewage) water, wash the residue once,' then to treat the pulpy mass by means of a current of steam, and to add hydrochloric acid gradu¬ ally, until the mass is dissolved. A cloudy liquor will be the result; but this liquor, on being drawn off from the vat through a cloth, leaves its suspended matter upon the filter, and runs through as a clear fil¬ trate. The contents of the filter are to be washed with hot-water, pressed and dried carefully in hot-air currents. It consists of the sus¬ pended organic matter of the original sewage and precipitate, together with some sulphate of lime, if a sulphuric solution of “Alta Vela” or other mineral phosphate has been the de¬ fecating agent employed. Being composed of organic and sandy matters in chief, it would be a very advan¬ tageous addendum for rendering clay soils loamy and rich. It might, also, serve as material for the manufacture of ammonia salts, as suggested at page 49. The clear filtrate which has run from it is PRECIPITATE FROM SEWAGE. 407 the counterpart, in a chemical sense, of a solution of “Alta Vela Guano" in sulphuric acid ; excepting- that it has been made with the much cheaper hydrochloric acid, and less expensively as to time, labour, or manufac¬ turing items. In this form it is again ready for treating crude sewage, and, being a purer liquor than a special solution of raw mineral, will produce better results. But a prime advantage which this mode of treatment possesses is, that it will, when re¬ quired, render the great enterprise of sewage purification quite independent of any further supply of mineral phosphate or “ mother - liquor " after that quantity which is consumed for the treatment of the first batch of sewage; for it reclaims the defecating agent over and over again for the repetition of its service an indefinite number of times. In scarcely less important degree, it exerts a valuable indus¬ trial influence by thus liberating the mineral phosphates of alumina and the “ mother- liquor", for an expansive sphere of useful¬ ness. 408 PURE FERTILIZERS. Secondly. As Material for Alum , Pure Phosphates of Alumina , and Pure Phosphates of Lime . The precipitate itself, whether made with or without the intervention of sewage, is, by reason of its comparative purity and great solubility in acids, a most valuable raw mate¬ rial in the manufacture of alum, crude phos¬ phoric acid, pure phosphates of alumina, pure bi-, di-, and tri-phosphate of lime, and pure aluminate of soda as a ready saponifier for making superior soap. It has, also, the capacity for being made to replace silicate of soda as a cheapener of common soaps. All of these products are in great request, though few of them have yet appeared in the market to any large extent, because hitherto an adequate source of them has been wanting. The processes of Peter Spence, John Ber¬ ger Spence, Peter Dunn, and Joseph Towns¬ end, for converting “ Redonda Guano” into alum and crude phosphoric acid, as already set forth, offer means which will apply advan¬ tageously to this precipitate. From this latter PRECIPITATE FROM SEWAGE. 409 all of the phosphates of alumina and lime can be made in pure forms most easily and profitably by direct combination. As a basis of these processes, either the phosphate sewage precipitate or the “ mother- liquor" of mineral phosphates of lime has very great advantages over “Alta Vela” and kindred minerals in all the relations of manu¬ facturing economy and convenience. All that remains to be added in this con¬ nection, therefore, are practical instructions for the elimination of the pure phosphate of alumina constituent, and for the manufacture of aluminate of soda. Thirdly and Fourthly. Aluminate of Soda or Ready Saponifier , and Common Salt. Aluminate of soda may be made either directly from the precipitate or from the solu¬ tion of this latter, when it has been dissolved in hydrochloric acid for the separation of its organic matter, as explained already. Supposing that the clear filtrate which runs through from the organic matter is taken as the basis, then it is only necessary 4 io PURE FERTILIZERS. to bring it to boiling by steam-currents, in wooden vats lined with lead, and then to add soda-ash in just sufficient quantity to neutralize the acid and precipitate all the alumina and phosphate of alumina. This being done, the whole is allowed to rest, but must be kept warm by enamelled tubes, through which there is a continuous circulation of steam. Lime, as milk of lime, may be substituted for soda-ash without difference as to manipu¬ lations. Caution must be observed to add it through a fine sieve, so as to prevent the passage into the liquor of coarse particles and the presence of any great excess in the result¬ ing precipitate. As soon as the precipitate or deposit settles at the bottom of the vat, the clear liquor above is to be drawn off into a pan and evaporated to dryness. This eva¬ porated mass will be common table salt when soda-ash has been employed, and chlo¬ ride of calcium if milk of lime was the preci¬ pitant ; and both have a commercial value. In case the hydrochloric acid may have contained any arsenic, the chloride of sodium product will be similarly contaminated, and PRECIPITATE FROM SEWAGE . 4i 1 the use of the latter must, therefore, be re¬ stricted to the manufacture of soda-ash. The precipitate is next to be washed with several relays of fresh water and heated by steam-currents during each washing. When the first wash-water has been re¬ moved, commercial caustic soda of best quality is to be added to the precipitate in the same vat and during constant ebullition, by means of steam-currents. By prolonged boiling, the alumina and phosphate of alumina become dissolved, while oxide of iron and phosphate of iron, if any are present, will remain as brown in¬ soluble residue. To provide against any ex¬ cess of soda in the solution, it were better that a small portion of the aluminium compounds should be left with this insoluble residue. Sufficient repose must now be allowed, in order that the liquor may settle clear. This liquor is an aqueous solution of aluminate of soda, containing more or less of phosphate of soda with phosphat-aluminate of soda, which latter assimilates to the former in pro¬ perties quite near enough for the practical purposes under explanation. 412 PURE FERTILIZERS. The liquor needs only to be drawn off into a clean pan, and evaporated to the state of a thin syrup, and left to cool, in order that most of the phosphoric acid may crystallize out as phosphate of soda. These crystals, being separated by filtration or draining, are to be washed and dried for market. The “mother-liquor” from which they are drained, on being evaporated to dryness, becomes a “ ready saponifier ’ or crude aluminate of soda. When it has reached the consistence of a mush in this pan, it is to be transferred into other and more shallow pans to cool. Thence it is to be packed in sheet-iron boxes, about two feet square and twelve inches deep, covered with closely-fitting lids. These are to be placed in large furnaces, heated to low red heat, carefully regulated, so as not to destroy the boxes. In about an hour, the moisture will have passed off, and the contents of the boxes will be beautifully white, with a blue tinge, possibly. After cooling, the contents of the boxes are to be emptied into barrels fitted with PRECIPITATE FROM SEWAGE. 4 i 3 tight covers and ground in a mill to coarse powder as soon afterwards as possible. Finally, it is to be packed in paper board boxes, the joints and inner surface of which are to be fastened and coated with a dense aqueous solution of silicate of soda. On drying, this leaves a glass-like surface, which protects the box from the corrosive character of the powder. The saponifier should be made of uniform composition always, so that a box of certain size may contain a sufficient weight to saponify a certain weight of melted fat and of water measured by the same box twice or more times filled. In this manner, weights may be dispensed with, to the great con¬ venience of the million ; for this material will enable every housewife or servant of common intelligence to make her own soap with the kitchen fat. This saponifier is wholly soluble in water, and though the alumina acts the part of an acid to the soda base in this solution, it holds on by such a feeble tenure that it will desert its chemical union upon the slightest provocation. Thus, when the solution is 4 T 4 PURE FERTILIZERS. brought into contact with the melted fat, the latter seizes the soda and water to form soap; which will have a greater hardness than usual, by reason of the diffusion through the paste of the alumina and phosphate of alu¬ mina which are set free during the saponify¬ ing reaction. Even the carbonic acid of the air would decompose it, and therefore the packages must be sealed around the joints of the cover with a narrow strip of paper; then dipped into a hot mixture of resin and pitch, and finally covered, while warm, with an envelope of strong paper to render it hermetically close. Fifthly. Pure Phosphate of Alumina. If it is desired to make pure phosphate of alumina, then, instead of evaporating the previous solution of aluminate and phos- phat-aluminate of soda, it must be treated in the cold with barely enough of sulphuric or hydrochloric acid to neutralize exactly the soda constituents ; for, at that precise point, the alumina and phosphate of alumina will become insoluble and precipitate in a pure PRECIPITATE FROM SEWAGE. 4 i 5 state. After repose, the clear liquor above is to be drawn off, and the precipitate is to be washed thoroughly by several relays of fresh water kept at boiling temperature by cur¬ rents of steam entering the mixture. Finally, it is to be drained on a filter, pressed and analyzed to determine the amount of free alumina which it may contain. It is then ready to be combined with the necessary proportion of phosphoric acid for converting it wholly into phosphate of alumina soluble or otherwise, as may be required. The more alumina which the mineral pre¬ cipitate or “ mother-water" may contain, the greater is its value for these purposes ; and thus, by the proposed treatment, they will acquire an appreciation per pound where they only have it now per ton. Phosphate of Alumina in the Manufacture of Sugar. The great advantages of the aluminium compounds in the manufacture of sugar have been recognized, since a long period, by che¬ mists; but certain objectionable features, per- 416 PURE FERTILIZERS . taining to all except phosphate of alumina, have prevented their application in that art. Until later years there was no source of a large and regular supply of phosphate of alumina at a reasonable price, and hence it was only about i860 that it began to be em¬ ployed. It was first introduced by Reynoso into the manufactory of M. de Alma, in Cuba (Journal de Pharm. et de Chimie , p. 232, vol. ii, 1865). The great practical success there realized with it as a means of effecting the almost absolute defecation of cane-juice, has been confirmed more recently by Domi¬ nique, in France, who has reported his ex¬ perience to The Sugar-Cane of July, 1870, P- 4 i 5 - The phosphate of alumina, dissolved in phosphoric acid, having been poured into the cane-juice, milk of lime is then added. A precipitate of phosphate of alumina ensues, carrying down with it some alumina, all the lime in combined and free states, together with the colouring and nitrogenous matters of the original juice. The latter is thus left pure for concentration, by freezing or heating and PRECIPITATE FROM SEWAGE. 4 i 7 crystallization, as it now contains only sugar and some normal saline associates. The precipitate, on being pressed and dried below 200° Fahrenheit, forms a rich and valuable fertilizer. Phosphate of Alumina in Dyeing. “ M. Collas, of Paris, has succeeded re¬ cently in using phosphates as a mordant in dyeing and calico-printing. To this end, he passes the yarn or the cloth through a weak solution of a phosphate in an acid and after¬ wards through a dye bath or an alkaline bath, by means of which the phosphate is fixed upon the fibre.” (It may be phosphate of lime or phosphate of alumina.) “ The stuff prepared in this manner is ready to be dyed with aniline or other colours. The stuff thus prepared may be passed through a solution of tannin before being dyed or printed. Thus, for instance, in order to dye in dark colours, the yarn or cloth is immersed in a warm and clear de¬ coction of one kilogramme of sumac in four and a half litres of water at 84° to 104° Fah¬ renheit, after which the stuff is wrung out. E E 418 PURE FERTILIZERS . It is then to be immersed in an acid solution of the phosphate of 50° Baume, for twenty or thirty minutes. On being then wrung out and washed, it is ready to be dyed. Purple, especially, yields fine hues. “ In order to dye with insoluble colours, the cloth is immersed in a mixture of gela¬ tinous phosphate with a solution of gelatine in water, at 75 0 to 85° Fahrenheit. “ Cochineal lake may be prepared in this manner by stirring gelatinous phosphate into a filtered decoction of cochineal.” Phosphate of Alumina as a Glaze for Pottery . This salt is in much request by potters, as a glaze, and would find a constant, as well as ready market, if put forward at a reason¬ able price. CHAPTER XXII. ON SPECIAL FERTILIZERS AND THEIR PREPARATION. Practically, the object of fertilizers is to cause small areas of land to produce the crops of very much larger ones, with the least possible amount of labour. Chemically, they are the food of plants and act in a twofold manner: first, by nourishing them directly; and, secondly, by transmuting the inert matters of the soil into forms and conditions which will promote the growth of vegetation. A seed which may be sown, although it is the germ of a crop, has no power to vegetate and ripen, except through the means of ex¬ ternal stimulants. In all the stages of vegetal growth the physical structure of the soil is only less im¬ portant than its chemical composition. It E E 2 420 PURE FERTILIZERS . must be neither too porous, like sand, nor too compact, like clay; but should have a temperament midway between the two. Hence, in many fields it is as necessary as the application of fertilizers, to make an ad¬ justment of this nature by suitable mixture of different kinds of soil. A soil, to be fertile, should contain the following elements :— Sand Clay Gravel = as its mechanical agents. Organic matters con¬ taining humus Nitrates Ammoniacal salts Potassa = as its assimilable and active agents. Soda Lime Magnesia Oxide of iron Oxide of manganese Sulphuric acid Phosphoric acid (partly soluble) Silicic acid (soluble) Chlorine — as its mineral agents. MORFl't Specially dean Truhiier '& Cv.60 Paternoster Row. MORFIT on the Manufacture, of Fertilizers. SUPERPHOSPHATE WELLS FIG. 3 . FIG. 2 . 3 - T ' ~T——1 I- 1 SCALE OF FEET 10 . .15 TO 25 Plate 24 50 3=! FROM & END ELEVATION 8c SECTIONAL PLAN. S*- ;ecMly deai^'tedforDT Mcafit's Work oil Fertilizear^. V3ricea.itBrooks D v \v k Son. Jjith Truhneri CL 60 paternoster Row. SPECIAL FERTILIZERS. 421 In addition, there should be a reserve of rocks and organic matters, from which the decomposing influences of air, time, and the soil, will eliminate the foregoing elements at later periods, as will be necessary to insure a permanent fertility. The mechanical portion serves to facilitate the passage of water through the soil ; and, consequently, to precede its chemical action in the premises. This action consists in ab¬ sorbing and dissolving carbonic acid, ammo¬ nia, and other desirable elements from the air and the soil, and rendering assimilable by these means the elements of the latter, which otherwise would remain inert. Thus it assists, not only directly, but indirectly, in the nutrition of plants, and more particularly in the development of their organic portion. A clay-soil requires, therefore, to be deeply ploughed. The inorganic portion derives its constitu¬ tion from the mineral elements of the soil. By repeated cropping, a soil becomes ex¬ hausted of its fertilizing elements; and they must be restored, therefore, from time to time, by means of deep ploughing, and the application of manures. 422 PURE FERTILIZERS . All plants are not alike, either as to the quality or quantity of their food ; that is, certain species are so far eclectic in this re¬ spect, as to exercise a greater avidity for the kind which is richest in their predominant element. Therefore, each of the great fami¬ lies of plants must be manured according to its peculiar appetite. Thus, for example: nitrogen and phosphates of lime are the pre¬ ferred nutriment of the cereals, including cotton ; nitrogen and potassa are the choice of the leguminous class ; and phosphates, potassa, and nitrogen that of the roots. The gramineous family differs very little from the roots in its appetite. But even though one of these elements may be dominant in distinct or individual crops, the latter cannot attain to a normal or abundant harvest, unless their peculiar food in the soil is associated, in degree at least, with all of the other requisite elements. The fertilizer is to be applied to the soil and intermixed thoroughly with the sur¬ rounding earth from the roots upwards. Its components must be in conditions for acting together within a given time, in order to pro- SPECIAL FERTILIZERS . 423 duce a wholesome growth of the crops. In¬ deed, it is expedient to have a portion of the fertilizer in active forms, so that in the early stage of the development of the plants, the latter may acquire that vigorous constitu¬ tion which will enable its organs to exert all their powers of assimilation and progress to a fruitful maturity. Saline manures, or those directly soluble, are liable to diminish the crops on light soils and dry seasons, more particularly when they may be mixed in injudicious or ex¬ cessive proportions. The more favourable season for applying them, therefore, is a wet one, which will promote their thorough diffu¬ sion through the soil. Keeping in view the foregoing principles, then, the following skeleton formula will re¬ present a fertilizer of just constituent rela¬ tions for general purposes. Phosphoric acid - - 35 'co Potassa - - - 45-00 Ammonia - - - - 20'00 IOO'OO These arc the prime elements of fertiliza- 424 PURE FERTILIZERS. tion ; but, being always accompanied in natural soil or artificial fertilizers with the necessary associate elements of plants, they constitute a complete manure for any crops. The proportion of 250 to 300 lbs. of manure containing these three prime ele¬ ments in the percentage ratio above noted, will suffice to stimulate an acre of ground into the production of an abundant harvest, and leave behind some residue for the suc¬ ceeding year’s crops. From this reserve, however, the predominant element of the harvested crops will have been almost, or nearly, entirely exhausted. This fact must be remembered in the rota¬ tion of crops ; so that in making one kind succeed another, the elementary relations of the subsequent fertilizer may be modified accordingly. In other words, having grown a crop of roots this year on a plot of ground manured with the normal fertilizer, then, if it is desired to prepare that plot the next year for a harvest of cereals, care must be observed to make the fertilizer richer in phosphate; so as to restore the normal condition of the soil which has been disturbed by the peculiar SPECIAL FERTILIZERS. 4^5 exigency of the previous root-crop as to that element. Such are the simple rules which should regulate the composition and application of special fertilizers ; and, if faithfully practised, will, with the divine favour of rain and sun¬ shine, eventuate in successful cultivation and profitable harvests. Normal Fertilizer . Bi-phosphate of lime (CaO, 2HO, P0 5 ) - io'oo Colombian or precipitated phosphate of lime* - 30-00 Chloride of ammonium - 25-00 Chloride of potassium - - - 25-00 Chloride of sodium - 3-00 Sulphate of lime (CaO, S 0 3 , 2IIO) - - 7*00 ioo-oo The above formula will serve for any plant, as it contains the elements of fertiliza¬ tion in very judicious proportions. Never¬ theless, for special crops it may be modified with some advantage, and according to the * The fertilizer must be kept dry always when it con¬ tains precipitated phosphate in association with bi-phos¬ phate, otherwise some of the latter might “go back” into di-phosphate. 426 PURE FERTILIZERS . examples which will be given after the next paragraph. Universal Danger. There is a popular general manure made in Germany by Hosch and Enderich, which has the following composition. It is of a greyish-yellow colour, free from strong odour, and reddens litmus paper. Water - Organic and volatile matters (ammonia, pSo) Soluble bi-phosphate of lime (CaO, 2HO, P 0 5 ) Di- and tri-phosphates of lime Sulphate of potassa Sulphate of lime Sand, silica, etc. - 1472 - 26-81 - 10-13 - 19-48 - 8-46 - 20-40 100-00 Fertilizer for Cereal Crops. In this family, comprising wheat, rye, rice, Indian corn, barley, and cotton, the prevail¬ ing elements of nutrition are nitrogen and phosphate of lime, with a considerable amount of alkaline salts. The normal fertilizer should, therefore, be modified and composed after this formula :— SPECIAL FERTILIZERS. 42 7 Bi-phosphate of lime - 15-00 Precipitated phosphate of lime - 3 5 '°° Chloride of ammonium - 25*00 Chloride of potassium - 18*00 Chloride of sodium - 3 00 Sulphate of lime 4*00 10000 Fertilizer for Leguminous Plants. Beans, peas, and other members of this family of plants contain potassa, nitrogen, and phosphoric acid, as their prevailing ele¬ ments. Therefore, the following formula must be observed in preparing fertilizers such crops :— Chloride of potassium - 40*00 Chloride of ammonium 1 to d 0 Bi-phosphate of lime - iS'oo Precipitated phosphate of lime - 2000 100 00 Fertilizer for Gramineous Plants. For the family of grasses, potassa is the dominant element ; and next in order are nitrogen, lime, and phosphoric acid. Conse¬ quently, a suitable manure should consist of:— 428 PURE FERTILIZERS. Chloride of potassium - 30*00 Chloride of ammonium - 25*00 Sulphate of lime - 18-oo Bi-phosphate of lime - I O'OO Precipitated phosphate of lime - 13-00 Chloride of sodium - 4*oo 10000 Fertilizer for Sugar. Sulphate of potassa - - 35*00 Nitrate of soda - 40-00 Bi-phosphate of lime - 10*00 Precipitated phosphate of lime - 15-00 It is a prevailing idea that alkaline chlo¬ rides should be excluded from fertilizers for sugar because of their deliquescing influence upon sugar, and it is in conformity with this prejudice that the formula has been con¬ structed. But the true and scientific posi¬ tion of the question has been recently set forth by E. Feltz ( Journ . des Fabricants de Sucre , 1870, p. 52), and A. Marschall ( Jour¬ nal of the Chemical Society , 1870, p. 457). The former chemist concludes, from his ob¬ servations, “that uncrystallizable substances, whether invert sugar or those classed as organic non-saccharine bodies, are the true SPECIAL FERTILIZERS . 429 molasses builders, and that they act as such in two ways : 1st. By preventing a sufficient degree of concentration ; and, 2nd. By ren¬ dering a boiled mass so sticky, that even if sugar crystals are formed, they cannot be separated from the syrup.” Marschall obtained results from his expe¬ riments which led to classifying salts as— “ 1st. Negative molasses makers ; 2nd. In¬ different bodies ; and, 3rd. Positive molasses makers. The negative molasses makers, or bodies which diminish the solvent power of water for sugar are, sodic sulphate, nitrate, acetate, butyrate, valerate, and malate; mag- nesic sulphate, nitrate, and chloride ; and calcic chloride and nitrate. “The indifferent bodies which are without influence on the crystallization of sugar are potassic sulphate, nitrate, chloride, valerate, oxalate, and malate ; sodic chloride, carbo¬ nate, oxalate, and citrate, and caustic lime. “Positive molasses makers are potassic car¬ bonate (saline co-efficient 3*8), butyrate (saline co-efficient 0*9), and citrate (saline co-effi¬ cient = o*6). Belaine was shown to be a negative molasses maker.” 430 PURE FERTILIZERS. Haughton Gill (Journal of the Chemical Society , 1871, p. 269) also contributes an in¬ teresting paper on the saline compounds of sugar. Fertilizer for Root Crops. Potatoes, carrots, beets, turnips, and the like, require mostly potassa; next nitrogen ; then lime; and, lastly, phosphoric acid. They must, therefore, be cultivated with this mix¬ ture :— Chloride of potassium - 30*00 Chloride of ammonium - 25*00 Sulphate of lime - 20*00 Bi-phosphate of lime - 10*00 Precipitated phosphate of lime - 15-00 100*00 Nitrate of soda may replace the ammonia- cal salts as the source of nitrogen, but five parts of the former must be taken in place of three of the latter, those being their equi¬ valent proportions. All the other elements of fertilization will be found generally in the soil ; and the plant acquiring full vigour in its early growth from SPECIAL FERTILIZERS . 43 i the fertilizers prescribed, will be able to assimilate whatever additional nutriment it may need from the surrounding sources of the earth and air. In all cases, the land must have been well limed within two or three years, in order to rouse, chemically, its organic matters; but not immediately preceding the application of the fertilizers by many months. For if the lime has not been in the ground long enough to have become wholly carbonate, or com¬ bined otherwise, it would cause a waste of the ammoniacal salts. In connection with this subject, the reader will do well to study the instructive paper of Dr. Aug. Voelcker, F.R.S., “ On the Produc¬ tive Powers of Soils in Relation to the Loss of Plant Food by Drainage", which is pub¬ lished in the Journal of the Chemical So¬ ciety for 1871, p. 276 to 297. CHAPTER XXIII. 9 FORMULAE FOR THE CHEMICAL ANALYSIS OF PHOSPHATIC MATERIALS AND PRODUCTS The phosphates of lime which come under chemical treatment for conversion into fer¬ tilizers have either an animal or mineral origin, but most generally the latter. Mineral phosphates differ in composition with their source and the care employed in preparing them for market. It becomes, therefore, indispensable to a well regulated system of manufacture, that each and every invoice of them which may be intended for conversion into fertilizers shall undergo, pre¬ viously, a full chemical analysis. The full analysis is particularly necessary, in order to distinguish what proportion of the phos¬ phoric acid may belong to alumina, iron, and other bases than lime. A correspondingly rigorous inspection CHEMICA L A NA L \ T S IS. 433 should be practised also in regard to com¬ mercial superphosphates of lime, and indeed all kinds of artificial fertilizers, for the pro¬ tection of the consumer and in the cause of honest trade. The necessity for such an ab¬ solute custom will be seen in the very wide differences in the samples which may come under examination. This great diversity between their pretended and actual composi¬ tion-value, is due either to fraud or unskilful manufacture, and frequently to both. The highest average per cent, of soluble bi-phosphate of lime in commercial samples is 20 to 25 ; but this strength is peculiar to the products of certain manufacturers only. More generally they fall below 20 per cent., and often as far down as 5 to 10, without a corresponding decrease in price. The amount of contained soluble phos¬ phate of lime is often represented, in the analytical report, by the higher figures of bone-phosphate of lime to which it is equiva¬ lent. For example, every per cent, of soluble bi-phosphate of lime in the fertilizer is writ¬ ten as 132, which latter record is a deception, having the effect of misleading the purchaser. F F 434 PURE FERTILIZERS . As a protection against errors of either accident or intention, the following instruc¬ tions in detail are given for the chemical analysis of such materials and products as come under consideration in this treatise. They are arranged to detect and estimate any and every element that is likely to be present. It is merely necessary to add that a certain familiarity with chemical principles and manipulations is indispensable on the part of the operator who may undertake to carry through an analysis. Bone-Ash, and Mineral Phosphates of Lime. All of these substances may be embraced in one general formula. The water used in the analytical operations must have been distilled ; and it is also imperative to have the reagents chemically pure. Previous to commencing the analysis, one or two sheets of blank writing-paper must be folded and stitched in book form, as a laboratory record or legend of the progressive steps of the analysis. The first step is to select a fair average CHEMICAL ANALYSIS, 435 sample of about half a pound of the ash or mineral to be analysed, mix it well, and then reduce wholly to powder about an ounce of it. A clean polished mortar, of iron or steel, is best for this manipulation. i. Accidental Water or Moisture. Fifty grains of this powder are to be weighed upon a delicate balance. Besson, Rue de la Ferronnerie, Paris, makes a very suitable instrument for ordinary work at the low price of ^5. But there is certain necessary supplementary apparatus which, with packing, will increase the cost to about £&. This consists, in part, of two deep watch- glasses, agreeing precisely in weight, so that one shall be a counterpoise of the other. The powder to be weighed is placed in one watch- glass ; while the opposite pan of the balance contains the duplicate glass as a counter¬ poise, together with the required weights. This promotes both a neat and convenient manipulation. The other supplement is a set of fine weights, ranging from 1000 grains to one- hundredth of a grain. The larger ones F F 2 43 ^ PURE FERTILIZERS. should be of gilt brass, and the smaller ones of gilt aluminium. The balance is of brass, and should turn, when fully loaded, with the hundredth of a grain. This degree of deli¬ cacy must be insisted on when giving the order. Fig. 12 shows the form of the balance. The watch-glass a , fig. 13, containing the 50 grains, precisely weighed, is next to be placed on a hot sand-bath c y with an inter¬ vening piece of hollow metal tube b, about two inches high, as a support, and to form a CHEMICAL ANALYSIS. 437 hot-air chamber between the sand and the bottom of the watch-glass. The sand-bath may be a plain or porcelain-lined iron pie dish, containing white sand, and heated by a rig. 13- gas-burner d, on a sliding-holder e, so that it may be lowered or raised at will upon the upright support ff made of iron. Here the powder is allowed to remain over a heat not exceeding 212° Fahrenheit, until it ceases to lose weight; and for determining 43 ^ PURE FERTILIZERS. this point, it must be weighed from time to time, with its counterpoise-glass always in the opposite pan of the balance, until the weight becomes constant. The constant weight shows a loss, and this loss doubled represents the per cent, of accidental water or moisture in the original sample or raw material. If there should be any constituents of the mineral containing constitutional water, such as sulphate of lime or sulphate of ammonia, they will not lose it at the temperature just prescribed. 2. Organic Matter and Constitutional IVater. The weighed residue is next to be trans¬ ferred, carefully, to a platinum crucible, and heated to redness until all volatile matter is expelled. This is known when, after repeated weigh¬ ings from time to time, the weight becomes constant, and a calx free from carbonaceous matter remains. Should any carbonate of lime be present in the raw material, this CHEMICAL ANALYSIS. 439 would lose some of its carbonic acid at the heat prescribed, and thus lead to error. As a preventive, the contents of the cruci¬ ble must be cooled, then moistened with some drops of aqueous solution of carbonate of ammonia, carefully dried, and heated only to dull redness for a few moments, so as to expel the ammonia without its carbonic acid. Restitution of lost carbonic acid being thus made to the lime, the crucible is allowed to cool and then weighed. The weight thus obtained, less that of the crucible, when de¬ ducted from the previous weight, will show a loss, and this difference, multiplied by two, expresses the per cent, of organic matter and constitutional water in the raw material. The residue, or calx, multiplied by two, re¬ presents the total per cent, of fixed or earthy matters, and is to be reserved, as a, for further treatment. Fig. 14 shows the mode of burning off the organic matter. The platinum crucible a is to be closed in the first part of the heating to prevent such a strong draught as might drive off unburned particles. Later, how¬ ever, the cover must be removed, and placed 440 PURE FERTILIZERS . as shown by a , so as to promote access of air. The steel tongs b, of proper form for hand¬ ling the crucible, are shown at the side of the gas-burner support. The trivet c, of plati¬ num wire, which is laid upon the ring g of the support as a rest for the crucible a , is shown by c c\ M0RF1T on the Manufacture of Fertilizers'. Truhrier & C? , 60 , Paternoster Row. Vincent Brocks, D ay &.Scsn, Lith. Specially designed for D r Morfit's Work on Fertilizers. CHEMICAL ANALYSIS. 441 If, in the progress of the analysis, the presence of salts containing constitutional water should be developed,—for example, sulphate of lime,—then the figures for this constituent are to be deducted from the vola¬ tile portion expelled by ignition. The resi¬ due doubled expresses the per cent, of total organic matter in the raw material. The precise figures for constitutional water will be obtained, as directed, a little further on, and in proper places. But, supposing, for example, that 5*8 are found to be, subse¬ quently, the per cent, of sulphate of lime, then, as the constitutional water is 0*2647 for every per cent., this proportion is to be de¬ ducted from the weight of organic matter and constitutional water. The residue ex¬ presses the amount of organic matter in the raw or original material. This constitutional water is not, however, to be formulated as a separate item, for it must be apportioned to the constituents to which it belongs, chemically. The manner of calculating it to its proper affinities will be explained hereafter. 442 PURE FERTILIZERS. with pure hydrochloric acid, covered with a glass dish or a deep watch-glass d, and 3. Sand and Silica; Soluble and Insoluble Organic Matters. Another portion of 50 grains of the pow¬ dered raw or original material is to be placed in a clean beaker glass a , fig. 15, drenched Fig. 15- CHEMICAL ANALYSIS. 443 digested over a gas flame c , until all the soluble matter has been taken up. It should be here noticed whether there is any effervescence on the addition of the hy¬ drochloric acid or any corrosion of the under surface of the glass cover of the beaker, for the first would denote the presence of carbonate of lime, and the latter that of fluoride of calcium. To modify the action of the flame, and to diminish the danger of fracture of the beaker glass, a fine wire gauze of brass or copper should be interposed be¬ tween the former and the latter; or, better still, a sand-bath b may be substituted for the direct flame. In either case, when the solution is complete, the cover is to be re¬ moved and the beaker glass further heated on the sand-bath for the evaporation of its contents to dryness. This expels all excess of acid, and renders the silica insoluble. At this stage, it is to be left to cool; after which, the contents are to be moistened with pure hydrochloric acid and a little water, and again heated on the sand-bath for 15 or 30 minutes. Water being now added for dilution, the liquor is then filtered upon a weighed or 444 PURE FERTILIZERS. counterpoised filter. The filtering operation is shown by figs. 16 and 17 : a being the Fig. 16. paper filter, properly folded; b, the glass fun¬ nel for holding it; c , the wooden support of Fig. 17. the funnel; and the beaker glass, to receive CHEMICAL ANALYSIS. 445 the filtrate or clear liquor passing through the filter. White paper, of a porous but strong texture, is made both in France and Germany, for filtering purposes ; and filters of different sizes may be bought ready cut at any dealers in chemicals and chemical apparatus. The weight of the ash of these filters is generally noted on the package. A counterpoised filter is one which has been weighed, with great precision, against a duplicate; and its use becomes necessary for weighing those precipitates which must be dried instead of being ignited. Con¬ sequently, the duplicate is to be marked al¬ ways, and dried with its original fellow, previous to being put into the opposite scale pan at the time of weighing. When the contents of the beaker have been poured upon the filter, there are still some solid particles adhering to the sides and bottom of the glass. These must be loosened by a feather, and washed out by means of a spritz bottle half filled with water. This spritz bottle, a, fig. 19, is an ordinary six or eight ounce vial, fitted with a cork bored in the centre for the passage of a glass-tube, 446 PURE FERTILIZERS . which must be drawn out fine at one end. By blowing through this tube, the internal air is compressed, and the bottle being dex¬ terously inverted, its water comes out with the force of a strong jet, which may be directed upon any desired point. After the entire contents of the beaker have thus been Fig. 18. Fig. 19. poured and spritzed upon the filter, the latter is allowed to drain. Plot water is then added three or four times, in order to wash out any traces of the solution. Each relay of water must be allowed to pass through the filter before its successor is poured on. The filtrate is b, and the filter is c. The filter c is to be placed first between the folds CHEMICAL ANALYSIS. 447 of bibulous paper, and then on a dish over a hot sand-bath, and there left to dry until it ceases to lose weight. The constant weight doubled, represents the per cent, of insoluble organic matter, sand, and silica, of the origi¬ nal raw material. This having been recorded in the legend, the filter and its contents are then burned to a calx in a platinum crucible. The organic matter is thus destroyed, and the calx being weighed, its weight doubled, less that of the crucible and ash, of the filter, deducted from the previous weight of the dried filter, expresses the per cent, of insolu¬ ble organic matter. The calx, multiplied by two, represents jthe per cent, of sand and silica. The amount of insoluble organic matter deducted from the total organic matter pre¬ viously estimated, gives the per cent, of soluble organic matter. 4 and 5. Sulphate of Lime, and Lime. The filtrate b having been on the hot sand-bath during all the interval, is by this time reduced very much in volume by evapo¬ ration, and thus prepared to receive a dose 448 PURE FERTILIZERS. of alcohol about equal to double its own volume, which must now be added. This will render insoluble and precipitate all the sulphate of lime which the liquor may con¬ tain. After eight to twelve hours of repose, it is to be filtered off and washed, by passing several relays of diluted alcohol through the filter. The filtrate is d, and the filter is e. The latter must be set to dry over a sand- bath. The filtrate D is next to be treated with pure sulphuric acid, added dropwise, until it red¬ dens a piece of blue litmus paper dipped into it. This precipitates all the residual lime, as sulphate of lime. After eight to twelve hours of repose, it is to be filtered off, washed with diluted alcohol, and the filter (say f) dried between the folds of bibulous paper, over a hot sand-bath, as before explained. The contents are then to be carefully transferred from the paper to a platinum crucible, and the filter paper rolled up and laid loosely at the top. Heat from a gas flame is then ap¬ plied, so as to produce a low redness, and when the paper is reduced to ash and the sulphate of lime has been well heated, the CHEMICAL ANALYSIS. 449 crucible and contents are to be weighed. This weight, less that of the crucible and ash of the filter, when doubled, expresses the total of lime, except that existing as sulphate in the original or raw material. This lime is to be apportioned among the phosphoric, carbonic, and organic acids, as will be ex¬ plained in the proper places. The filtrate, say g, is, in the meantime, set upon the hot sand-bath to lose its alcohol by evaporation. While this operation is going on, the filter e, now dry, is to be ignited and weighed after the manner just noted. The nett weight doubled, expresses the per cent, of dry sul¬ phate of lime (CaO, S 0 3 ) in the original material. But as sulphate of lime is na¬ turally hydrated always, it must be recorded with its proper equivalent of constitutional water affixed, which is 0^2647 for every per cent., and makes the formula CaO, SO3, 2HO. All the alcohol having been evaporated from the filtrate, aqua ammoniae is now added to the residual solution until the odour of the reagent is strongly perceptible. After six hours of repose, it is to be filtered 450 PURE FERTILIZERS. and washed with water containing aqua am¬ monia. The long repose is necessary, in order that the phosphate of magnesia may separate completely by crystallization. The filtrate is h, and the filter is j. 6. Phosphoric Acid. The filtrate h contains only the phospho¬ ric acid belonging to lime, and is to be treated at 90° Fahrenheit, first with a solu¬ tion of chloride of ammonium, rendered strongly ammoniacal and carefully stirred. Solution of chloride of magnesium is now to be poured in cautiously until a precipitate or even cloudiness ceases to form. The whole is then left for four or five hours to repose in the cold ; after which it is filtered, and the filter washed with water, rendered ammonia¬ cal ; then dried, finally ignited, and weighed. The precipitate formed is the phosphate of magnesia and ammonia (NH 3 , HO, 2MgO, P 0 5 , 12HO); but, by ignition, it loses its ammonia, and becomes pyro-phosphate of magnesia (2MgO, P 0 5 ). Every per cent, of this latter contains o‘639 per cent, of phos¬ phoric acid. This phosphoric acid belongs, CUE MICA L A NA L ] 'SIS. 451 as before stated, to lime, and must be written in the record as tri- or bone-phosphate of lime. To make this salt, every per cent, of phosphoric acid requires ri66 per cent, of lime = 3CaO, PO-. This proportion of lime is to be deducted from the total lime already estimated. Fresenius and many other chemists pre¬ scribe an allowance of one and three-quarter milligrammes, for every hundred cubic centi¬ metres of the combined filtrate and washings from the ammonia-magnesic-phosphate, to compensate for an equivalent portion re¬ tained obstinately in solution. But Parnell, with whose experience my own agrees, ob¬ serves that such a correction is rendered unnecessary by the presence of an excess of the strongly ammoniacal solution of mag¬ nesium salt. 7. Phosphate of Iron . The contents of the filter j # are to be transferred by means of a platinum spatula * When the alumina or iron is in large proportion it carries down, unavoidably, some of the phosphoric acid G G 2 452 PURE FERTILIZERS. and the spritz bottle to a small beaker, treated with pure hydrochloric acid, and digested on a hot sand-bath, until wholly dissolved. Aqueous solution of pure caustic potassa is then to be added in just sufficient excess to re-dissolve the alumina and phos¬ phate of alumina, which it precipitates at first. Oxide of iron and phosphate of iron with phosphate of magnesia remain undis¬ solved, and are to be filtered off, thoroughly washed with hot water to remove every trace of potassa; then dried, ignited, and weighed as filter k. The filtrate is l. The weight of the calcined filter ic ex¬ presses the quantity of oxide of iron, phos¬ phate of iron, and phosphate of magnesia combined, which the raw material contains. To estimate them separately the calx is to be put into a beaker, and dissolved by the heat of a sand-bath in just sufficient hydrochloric belonging to lime. To prevent this source of error, lam now engaged in experiments by which the manufacturing processes, described at pp. 223 and 241, will be rendered precise analytical methods for separating phosphate of lime from its association with iron and aluminium com¬ pounds. CHEMICAL ANAL YSIS. 453 acid for the purpose. Aqua ammonia is next added, until the liquor blues red litmus paper, and then acetic acid in excess. Oxide of iron and phosphate of magnesia are held in solution, while phosphate of iron precipi¬ tates. This latter is to be filtered off, washed with hot water, dried and ignited, and weighed. The weight doubled, expresses the per cent, of ferric phosphate in the raw ma¬ terial. The composition of this ferric phosphate varies with the temperature of the liquor, its state of dilution, and the strength and pro¬ portion of the aqua ammoniac employed as precipitant. If the quantity is large, its con¬ tent of phosphoric acid must be determined by separation after the manner hereinafter described. 8 . Oxide of Iron. The filtrate from the phosphate of iron— containing the phosphate of magnesia and oxide of iron—is now to be diluted largely with boiling distilled water, treated with aqua ammoniae,/^/ to perfect neutralization, and filtered rapidly. The oxide of iron on 454 PURE FERTILIZERS. the filter is to be washed with hot water, dried, ignited, and weighed. The weight doubled, expresses the per cent, of that ele¬ ment contained in the original raw material. It is indispensable to have the liquor dilute, hot and free from any excess of free ammo¬ nia, so as to prevent the oxide of iron carry¬ ing with it some of the phosphate of mag¬ nesia. 9. Phosphate of Magnesia. The filtrate from the oxide of iron, just mentioned, is to be evaporated to a small volume upon the sand-bath, allowed to cool, then treated with aqua ammoniae in excess , and set aside for ten to twelve hours. At the end of this time, the phosphate of mag¬ nesia will have crystallized out, and is to be filtered off, washed with ammoniated water, dried, ignited, and weighed. The process of ignition drives off the ammonia, and changes it into pyro-phosphate of magnesia (2MgO, P 0 5 ), every per cent, of which contains 0*639 of phosphoric acid. CHEMICAL ANALYSIS. 455 io and 11. Phosphate of Alumina , and A lumina. The filtrate l, which was set aside pre¬ viously, is now to receive attention. It con¬ tains alumina and phosphate of alumina dis¬ solved in caustic potassa. This latter is to be fully neutralized by the addition of hydro¬ chloric acid, which first precipitates and then re-dissolves the aluminium compounds. To throw them down wholly, it is next necessary to add carbonate of ammonia in excess. They are then filtered off, thoroughly washed with hot water, dried, ignited, and weighed. The weight expresses the joint amount of alumina and phosphate of alumina in the raw material, and is to be noted in the record. The next step is to transfer the contents of the platinum crucible to a beaker glass ; add hydrochloric acid ; heat the solution on a sand-bath; and dilute largely with water. This done, a large quantity of solution of citric acid is to be poured in ; and, finally, aqua ammonise, with a slight excess of solu¬ tion of sulphate of magnesia containing chlo- 456 PURE FERTILIZERS. ride of ammonium. The vessel is then covered, and left to repose in a cool place for twenty-four hours ; after which, its contents are to be filtered and washed with dilute ammonia water. The filter contains the phosphoric acid as phosphate of ammonia and magnesia, but mixed with greater or smaller traces of alu¬ mina and basic citrate of magnesia. To re¬ move these, the contents of the filter must be dissolved in hydrochloric acid, treated anew with a very small quantity of solution of citric acid, and re-precipitated by ammonia. After being washed with ammoniacal water, dried, and ignited, it is to be weighed as pyro-phosphate of magnesia (2MgO, P 0 5 ), every per cent, of which contains 0*639 of phosphoric acid. As this portion of phos¬ phoric acid belongs, naturally, to alumina, it must be calculated to the latter, and written down in the table of results as phosphate of alumina. Every 1*0 of phosphoric acid re¬ quires 0*722 of alumina. The proportions of phosphoric acid and alumina thus determined being subtracted from the joint amount previously noted, give CHEMICAL ANALYSIS. 457 the proportion of alumina in the mineral other than that which is combined with phos¬ phoric acid. As only fifty grains of raw material are taken for analysis, the figures of result must be doubled, in order to make them express the per cent. 12. Alkaline Salts. The calx a from the organic matter and constitutional water determined in an earlier stage (page 439) of the process and then placed in reserve, is now to be treated for the separation of alkaline salts and fluoride of calcium. For this purpose it is boiled with an ounce of distilled water, allowed to cool, and then filtered and washed. The filter is m, and the filtrate is N. The filtrate n contains the alkaline salts (with some little sulphate of lime, probably), and is to be evaporated to dryness in a pla¬ tinum capsule on a hot sand bath. Its con¬ stant weight less that of the capsule is then taken and noted in the tabular result as 453 PURE FERTILIZERS. alkaline salts. It must be doubled to ex¬ press the per cent. In rock guanos and mineral phosphates the alkaline salts consist, generally, of chlo¬ ride of sodium with sulphate of soda ; and their proportion is very small. But to de¬ termine whether any potassa is present, as well as to separate it in such case, the direc¬ tions hereinafter given on that point, for ana¬ lysis of superphosphates, must be followed. To determine whether any appreciable quantity of sulphate of lime remains with the alkaline salts, it is only necessary to add very dilute alcohol to the latter, after weigh¬ ing them, which will leave the former undis¬ solved. It can then be separated by filtra¬ tion, dried, ignited, and weighed. Its weight is to be deducted from the previous weight. 13. Fluoride of Calcium . If the presence of fluoride in the raw ma¬ terial was made evident by the corrosion of the glass cover to the beaker, in the earlier treatment for the separation of sand and silica, its quantity is now to be determined by fusing the contents of filter m in a plati- CHE MICA L A NA L VSIS. 459 num crucible with a mixture of six parts of carbonates of potassa and soda and two parts of silicic acid. This operation converts all the fluorine and phosphoric acid into soluble alkaline salts. The mass, when cold, is to be treated with water, which renders liquid the soluble salts. The liquid is to be filtered off, and treated with solution of carbonate of ammonia which precipitates the silica. This latter is to be filtered off, and washed with a dilute solution of carbonate of ammonia. The liquor is now to be treated with hydro¬ chloric acid until it reddens blue litmus paper, and afterwards with a slight excess of solution of chloride of calcium. Fluoride of calcium, together with phosphate of lime, drop from the solution, and this precipitate is to be filtered off, washed with hot water, dried, ignited, and weighed. The calx is now to be placed in a platinum capsule, and heated with sulphuric acid until all the fluorine is expelled as hydrofluoric acid. Care must be observed not to let the heat be sufficiently high to volatilize any of the sul¬ phuric acid. The residue is then digested with hydrochloric acid to dissolve the phos- PURE FERTILIZERS. 460 phate of lime, and afterwards with its own volume of alcohol to precipitate the lime as sulphate. After five or six hours’ repose this latter is to be filtered off, washed with alcohol, dried and weighed. Every ro of dry sulphate of lime contains 0*4117 of lime or oxide of calcium. The filtrate from the sulphate of lime is to be evaporated on a sand bath, for the vola¬ tilization of the alcohol, then treated with a mixture of sulphate of magnesia and chlo¬ ride of ammonium, and finally with an ex¬ cess of aqua ammoniae. After six or eight hours’ repose the phosphoric acid will have separated, wholly, as phosphate of magnesia and ammonia. This latter is to be filtered off, washed with hot water, dried, ignited, and weighed as pyrophosphate of mag¬ nesia. Every roof this latter salt of mag¬ nesia contains 0*639 °f phosphoric acid. The total of lime and phosphoric acid hav¬ ing now been determined, so much of the former must be apportioned, by calculation, to the latter as is necessary to make tri-phos¬ phate of lime, or, in other words, 1*166 of lime to every ro of phosphorie acid. The U #^KVunO(S. NOR FI T on the Manufacture of Fertilizers Specially designed.forKMorfits Work® Fertilizers. Vincent Brooks. Day &. Scm, Lath Triihner & C?.6O,PaiemosterR0w. PJcite SCALE loFeet Battery of Stone Vats and Accessories Front Elevation CHEMICAL ANALYSIS. 461 residue of lime belongs to the fluorine which is expelled, and every ro of CaO makes or is equivalent to 1*40 fluoride of calcium (CaFl). The figures obtained must be doubled to ex¬ press the per centage. 14. Carbonate of Lime. If on the addition of acid to the raw ma¬ terial, there is any effervescence, this action denotes the presence of carbonate of lime. To determine the amount, a separate or new portion of fifty grains of the raw material in fine powder must be taken, and treated in a special apparatus shown by fig. 20, which is drawn one-third smaller than the natural size. It consists of a very light glass flask a, as the vessel for receiving the powder ; a glass pipette b, and a drying tube c, containing chloride of calcium, both of which latter con¬ nect with the former by means of a tightly adjusted cork Ji. The pipette is to be filled with either sulphuric acid or a very strong solution of tartaric acid, by dipping the lower end into the liquor and drawing the latter up into the bulb by placing the 462 PURE FERTILIZERS. mouth at the upper end. This portion is then fitted with a piece of india-rubber tube and one of Mohr’s clamps d, shown enlarged by fig. f. The clamp and india-rubber tube serve to exclude or admit air into the flask as may be required ; it being only necessary to press upon the keys g g with the fingers when it is desired to open the tube, and to remove them when it is to be closed. When the weighed portion of powder has been put into the flask, the latter is to be closed tightly CHEMICAL A HAL VS IS. 4-63 with the cork stopper, and the whole appara¬ tus and contents carefully weighed on the fine balance. This weight having been noted in the record, the acid is then made to flow from the pipette in drops, by pressing the keys of the clamp at short intervals. Carbonic acid having a much feebler che¬ mical affinity than either sulphuric or tar¬ taric acids, is displaced by either of these latter from its combinations, and driven off in the form of gas, as indicated by the effer¬ vescence which takes place ; and if in its escape it should be involved with any me¬ chanically mixed water, this will be arrested by the chloride of calcium as it passes through the drying tube,—that salt being a hygroscopic substance. Nothing but car¬ bonic acid escapes; and after all the acid has been allowed to fall upon the powder, and effervescence has ceased for some ten or twenty minutes, the lips are to be applied to an india-rubber tube temporarily drawn over the end of the exit tube e, and the residual traces of gas drawn out of the apparatus by suction. This india-rubber tube being then removed, the apparatus is to be weighed 464 PURE FERTILIZERS. again. The difference between this second and previous weight shows a loss which ex¬ presses the amount of carbonic acid in the raw material. The carbonic acid is to be calculated to lime (CaO) and in the propor¬ tion of 1*27 lime to every 1.0 of carbonic acid. The equivalents of lime belonging severally to the fluorine and the carbonic and phosphoric acids being now added to¬ gether and deducted from the total of lime previously estimated, may leave a remainder. In that case the remainder is to be set down in the table as Lime with organic and silicic acids , and probably also with alumina. The results are to be arranged in the order shown by the following table. Recapitulation. Moisture - - say O O Organic matters - » 2^0 Sand and silica - 3 '°° Fluoride of calcium » 4-00 Sulphate of lime y> 5-00 Carbonate of lime » 7-00 Lime (with organic and silicic acids) - 2-00 Bone-phosphate of lime >> 58 00 Bone-phosphate of magnesia 3*50 Phosphate of alumina » 5 - 00 CHE MIC A L A NA L YSIS. 465 Phosphate of iron Oxide of aluminium Oxide of iron Alkaline salts say 3’00 2'00 roo 2'00 »> » Total 100*00 The phosphoric acid is thus shown in its individual combinations and not totalized as tri-phosphate of lime, according to the mere¬ tricious style of “ commercial ” chemistry. FORMULA FOR THE CHEMICAL ANALYSIS OF MINERAL PHOSPHATES OF ALUMINA AND IRON. In the preceding formula, instructions have been given for the separation of the alumi¬ nium and iron compounds from those of lime, because there are very few mineral phos¬ phates of lime which do not contain more or less of those compounds. On the other hand, there are certain mineral phosphates of alumina and iron wholly free from lime associates. To ana¬ lyze these, therefore, is a simple process, it being necessary to follow only those parts of the formula already explained, which apply 11 11 466 PURE FERTILIZERS. to their special components. Taking “ Re- donda Guano ’ as a typical specimen, these components are, in their proper order of arrangement, generally as follows :— Water - Organic matter - Sand and silica - Sulphate of lime - Phosphate of alumina Phosphate of iron - - Oxide of aluminium - Oxide of iron - Total a. Water. An average sample of about four ounces having been selected, is to be reduced, wholly, to fine powder in a polished iron or steel mortar. Fifty grains are then to be heated in a platinum crucible on a very hot sand bath, until the weight becomes constant. The loss of weight thus produced expresses, when doubled, the per cent, of water in the mineral. b. Organic Matter. The residue is further heated, but over a CHEMICAL ANALYSIS, 467 gas flame, to redness until it ceases to lose weight. The difference between its constant weight after the heating, and its previous weight, expresses, when doubled, the per cent, of organic matter in the mineral. c. Sand and Silica. The calx is then to be emptied from the crucible into a small beaker glass, drenched with hydrochloric acid, and heated on a sand bath. After an hour, sulphuric acid is to be added very cautiously, for otherwise too violent action may ensue, and cause the ejection of some of the contents of the glass. Enough acid must be added to thin the mass to fluidity. After which, digestion is to be continued until all the soluble matter is taken up, as will be indicated by the liquor having assumed a thick syrupy con¬ sistence without solid residue at the bottom. It is then evaporated to dryness on the sand bath, treated with a few drops of hydro¬ chloric acid and sulphuric acid, and again digested for ten minutes. Hot water being then added to make a thin dilution, the whole is to be stirred and filtered. The n II 2 468 PURE FERTILIZERS . washed, dried, ignited, and weighed filter represents the sand and silica. d. Sulphate of Lime . The filtrate may contain, in rare instances, some small portion of sulphate of lime; therefore its volume must be reduced two- thirds by evaporation on a sand bath ; after which a double volume of alcohol is to be added. If it contains sulphate of lime, this salt will precipitate, and must be filtered off, washed, dried, ignited, and weighed. e. Alumina and Phosphate of Alumina. The'filtrate contains alumina and oxide of iron together with their phosphates, and must be evaporated to expel alcohol. Solu¬ tion of caustic potassa is then added in ex¬ cess, so as to hold in solution the aluminium compounds while it precipitates those of iron. These latter are to be filtered off, washed with hot water, dried, ignited, weighed and set aside as a. The filtrate is now to be treated for the separation and estimation of its alumina, CHEMICAL ANALYSIS. 469 and phosphate of alumina, precisely in the manner described, for filter k, in paragraphs 10 and 11 of the preceding formula. f. Oxide of Iron and Phosphate of Iron. The calx a contains only these two com¬ ponents, and it is to be digested in a beaker glass with sufficient hydrochloric acid to effect its solution. The further treatment is then precisely similar to that described in paragraphs 7 and 8 of the preceding formula. FORMULA FOR THE CHEMICAL ANALYSIS OF COMMERCIAL SUPERPHOSPHATE OF LIME ; AND COMPOUND FERTILIZERS. The commercial superphosphates of lime vary in their composition, according to the skill and integrity which may have been practised in the manufacture of them. Che¬ mical analysis is the only mode of deter¬ mining their value previous to use, and should be made as follows. a. Water. Average the sample fairly, weigh out a portion of 50 grains in a counterpoised 4 ;o PURE FERTILIZERS. watch-glass, and dry over a sand-bath at 200° to 212° Fahrenheit until weight ceases to be lost. The loss which the constant weight indicates, will, when doubled, express the per cent, of accidental water in the sample. b. Bi-Phosphate of Lime. A fresh portion of 50 grains is to be tri¬ turated in a porcelain mortar with distilled water, and poured into a small glass funnel loosely plugged in its stem with cotton-wool. When the liquor has run through into a beaker glass beneath, a fresh relay of cold water is poured on and allowed to infiltrate through as before. In this way the infiltra¬ tion is further repeated thrice with cold, and subsequently several times with boiling water or until all the soluble matter has been displaced or washed out. This will be shown so soon as the filtrate, running through, no longer leaves a decided tache, when a drop has been evaporated to dryness upon a platinum spatula. The use of cold water insures the extraction of any soluble aluminium phosphate that may be present; CHE MICA L ANAL YSIS. 4; 1 for, according to Warrington, hot water would coagulate and keep it back. The filter is a, and must be kept in reserve as the insoluble portion. The filtrate b con¬ tains all the soluble phosphate, together with some little sulphate of lime, and any sul¬ phates of alumina and iron that may have been in the sample. It is to be reduced, by evaporation on a sand-bath, to a small volume, and treated with alcohol for the precipitation of the sul¬ phate of lime. This latter is then to be fil¬ tered off, washed, and added to the reserved filter a, containing the portion of the sample insoluble in water. Lime-water is now to be added to the filtrate c, a little at a time, until precipita¬ tion or cloudiness ceases to be formed. Great care must be observed to restrict the lime as nearly as possible to the exact quan¬ tity, and this is nice manipulation. The better way will be to keep back about one- eighth of the liquid, so that this reserve may be at hand for a readjustment of the neu¬ trality, in case of too much lime-water having been added to the first portion. Very thin 472 PURE FERTILIZERS. milk of lime, strained through a bolting or other fine cloth, may be used instead of lime- water, and with the advantage of producing less volume of liquid ; but, in this case, the manipulation must be more expert, so as to prevent the addition of any excess of lime. This treatment throws down all the phos¬ phoric acid as phosphate of lime, with any alumina and oxide of iron, which may have been present in the solution. The precipi¬ tate is to be filtered off, washed, and noted as d. The filtrate is e. The filter d is to be transferred to a beaker glass, and dissolved in just sufficient hy¬ drochloric acid, by the heat of the sand- bath. A small quantity of water is added, and afterwards a double volume of alcohol. Finally, sulphuric acid is to be added, a drop at a time, until all the lime has precipi¬ tated as sulphate. The sulphate of lime, thus formed, is then filtered off, washed, and thrown away. The filtrate contains all the phosphoric acid with the alumina and iron. It is to be evaporated on a sand-bath for the expulsion of alcohol, and then treated with ammonia to throw down the alumina and ClI'EM 1 CA L A NA L YSIS. 473 iron. Filter, wash well with hot water, and set aside as filter f, containing iron and alu¬ mina. The filtrate now holds only phosphoric acid, and is to be treated precisely as directed in paragraph 6 of the first formula. Every ro of phosphoric acid (P 0 5 ) is equivalent to, or makes, 1*64 of biphosphate of lime (CaO, 2HO, PO s ). If it is only desired to estimate the amount of soluble bi-phosphate which the sample may contain, the analysis here ends. But as this component is often associated in arti¬ ficial mixtures, with precipitated phosphate, bone-phosphate, ammoniacal and alkaline salts, it is proper that the formula should comprise instructions for a thorough analy¬ sis, in the progress of which, any and every probable component may be detected and estimated. c. Alumina and Iron. Therefore, the filter f is to be ignited and weighed. The weight having been recorded, the calx is then dissolved in hydrochloric acid by the aid of the sand-bath, and treated 474 PURE FERTILIZERS. with citric acid, as directed in paragraphs 7 to 11, for the separation of any phosphoric acid which it may contain. The weight of the phosphoric acid deducted from the pre¬ vious total weight of the calx leaves the weight of the aluminium and iron oxides. Both weights must be doubled to express the per cent, relations, and are to be recorded in the table among the soluble constituents of the sample. d. Chloride of Ammonium . The filtrate e having been poured into a platinum capsule of known weight, is to be evaporated to dryness upon or over a sand-bath at a temperature not exceeding 212 0 Fahrenheit. When it ceases to lose weight, its constant weight is to be noted. The crucible and contents are then to be heated over a gas flame, much below redness, until vapours cease to be given off. Chlo¬ ride of ammonium, if any is present, thus volatilizes ; and the capsule being now weighed will show a loss on its previous weight. This loss, doubled, expresses the per cent, of chloride of ammonium in the sample. CHEMICAL ANALYSIS. 475 ee. The residue is now dissolved in water, diluted to a given number of cubic centi¬ metres, and then divided into two equal por¬ tions, G and h. It should be remarked here, that the solution may contain both chlorides and sulphates of the alkalies, together with sulphate of ammonia. f. Sulphate of Ammonia. The portion g must be treated with chlo¬ ride of barium in a careful manner, so as to avoid an excess. The precipitate is then to be filtered off, washed with hot water, dried, ignited, and weighed. Every ro of this cal¬ cined filter of sulphate of baryta (BaO, S 0 3 ) contains 0*34335 of sulphuric acid, and this acid is to be apportioned, as will be explained hereafter. The sulphates having been converted thus into chlorides, are to be evaporated to dry¬ ness, as before, and the constant weight noted. Afterwards, the mass is to be heated, as in the previous instance, to expel any chloride of ammonium that may have been formed from sulphate. It must be weighed, therefore, again, to determine the amount of 476 PURE FERTILIZERS. loss, if any. Every i*o of this loss, being chloride of ammonium, represents 1*257 °f sulphate of ammonia. g. Potassium Chloride . The residue is then dissolved in water, and a little carbonate of soda added to precipi¬ tate any excess of baryta salt that may have been added. The liquor is then filtered and washed. The filter is thrown away ; but the filtrate is to be reduced, by evaporation, to a small volume, treated with a strong solution of neutral chloride of platinum in slight excess, and evaporated in a porcelain capsule nearly to dryness over a water-bath. A mix¬ ture of alcohol, of 80 per cent, strength, and ether, is then added, and the whole left to digest for some fifteen to thirty minutes. The double salt of chloride of platinum and potassium is thus rendered wholly insoluble, and must be filtered off upon a counterpoised filter, dried, and weighed. Every i*o of this salt (KC 1 , Pt, Cb) contains 0*30507 of chlo¬ ride of potassium, and every 1 *o of this latter salt is equivalent to i* 166 of sulphate of potassa, or 0*523 of potassium deducted from CHEMICAL AHA LYSIS. 477 the previous weight (paragraph f) gives the amount of chloride of sodium in the filtrate. To determine whether any of the potassium or sodium may have existed originally as chloride, it is first necessary to test the h portion of the liquor previously noted, with nitrate of silver. If any precipitate falls, it must be filtered off upon a counterpoised paper, washed with hot water, dried, and weighed. Every ro of the chloride of silver thus precipitated contains ’2472 of chlorine, and every ro of chlorine is equivalent to 2*io of chloride of potassium. The chlorine is allotted to potassium, first, because this latter is a stronger base than sodium, though it is possible a part of it may belong really to the latter, if it were known how to deter¬ mine that point and portion under existing circumstances. h. Sulphate of Potassa. If there should be more of potassium than the chlorine requires, this residue was origin¬ ally in the form of sulphate. Therefore, as much of sulphuric acid as it may require to convert it into KO, SO3, must be deducted 478 PURE FERTILIZERS. from the total baryta product of the portion of liquor g. Every ro of potassium needs 1*23 of oxygen and sulphuric acid jointly, to convert it into sulphate of potassa. j. Chloride of Sodium. If the amount of chlorine obtained should be more than sufficient for all the potassium, then the excess is to be calculated to sodium as chloride of sodium. Every ro of chlorine (Cl) is equivalent to 0*6486 of sodium (Na), or 1*648 of chloride of sodium (NaCl). This proportion of chloride of sodium is to be deducted from the total amount of soda salts, previously determined. k. Sulphate of Soda. The remainder of the sulphuric acid should exactly or closely fit the residual amount of chloride of sodium, already determined, as sulphate of soda is most probably the form in which it originally existed in the sample. Every ro of chloride of sodium is equivalent to 0*684 of sulphuric acid, and every ro of this latter makes 1*782 of sulphate of soda. As only 50 grains of the sample were CHEMICAL ANALYSIS. 479 taken for the analysis, and this portion was divided into moieties, for the estimation of the chloride of potassium and sulphates of potassa, soda, and ammonia, the figure results for these latter must be multiplied by four, in order to express the per cent, relations. l. Nitrate of Soda. Though this salt is not comprised in any of my products, it may be a component of other fertilizers, as it is now largely used in their manufacture; and, therefore, a proper formula for chemical analysis should com¬ prise instructions for detecting and esti¬ mating it. Its presence may be determined by leach¬ ing a sample of the fertilizer with water, filtering, and evaporating a few drops of the filtrate to dryness in a platinum crucible. If now, on adding to the dry mass a few drops of sulphuric acid and heating, there should be an appearance or smell of orange-red nitrous fumes, they are proof of the presence of a nitrate, which is most generally nitrate of soda. In that case, then, a fresh portion of 50 grains of the original sample is to be di- 480 PURE FERTILIZERS . gested in a beaker glass and on a hot sand- bath with distilled water. All the soluble matter of the sample will be thus taken up ; and the whole is to be filtered and washed. The filter, being foreign to this determina¬ tion, is to be thrown away. The filtrate is to be treated with thin and smooth milk of lime until this latter ceases to throw down a precipitate. Filter and wash. The filter containing alumina, oxide of iron, and phos¬ phate of lime, is to be thrown away; as all of these matters have been estimated accord¬ ing to the instructions in previous para¬ graphs. There remains nothing in the filtrate but alkaline salts and nitrate of soda, with some sulphate of lime. It is to be evaporated to dryness and constant weight, in a plati¬ num crucible the weight of which has been previously noted, and there is then to be added to the saline mass some pure powdered silica. The silica must be pre¬ viously heated, to insure perfect dryness, and its proportion must be four to six times the supposed weight of the nitrate of soda. The mixture of the two having been made together. v r i i t MOR FIT on the Manufacture, of Fertilizers. Elevator and Digestion Specially Designedfor ulMLrfeWoru on Fertilizers. Plate 27. Vats _ End Elevation. T'l'Ubner & C?,6Q, Paternoster Row. Viitcentbrooks^iiayficDon. Lull. CHE MICA L A NA L \ r SIS. 481 intimate by stirring with a glass rod, the whole is then carefully weighed and its exact weight recorded. The crucible being then covered, is to be heated for one half hour over a gas flame to a redness which is so low as to be only barely visible in the day time. At this temperature the nitric acid of the soda (or potassa) will pass off, while any alka¬ line chlorides or sulphate that may be pre¬ sent remains undecomposed. The crucible and contents being weighed again, when cool, will show a loss which represents the amount of nitric acid expelled. Every 1*0 of this nitric acid (NO s ) is equivalent to 0*5796 of soda (NaO), and represents 1*5796 of nitrate of soda. The result is to be multi¬ plied, of course, by two, in order to make it express the per cent, relations. The portion of the fertilizer soluble in water having been thoroughly analyzed, the next operations must be with the insoluble part which was placed in reserve as filter a, at an early stage of the examination. The quali¬ tative and quantitative steps are one and the same in this formula,—that is, they proceed together. 482 PURE FERTILIZERS. m. Precipitated Phosphate of Lime. The filter a having been perfectly dried, its contents are weighed and then transferred to a beaker glass. Pure concentrated acetic acid of specific gravity 1*05 is next to be added, and the whole left to digest in the cold for half an hour. By this treatment, carbonate and precipitated phosphate of lime are dissolved, while the bone-phosphate of the natural mineral remains nearly un¬ touched, on account of its dense physical structure. The whole is then filtered and washed ; the filter being j and the filtrate k. The filtrate k is treated with a slight ex¬ cess of aqua ammoniae filtered and washed. The filter is then dried, ignited, and weighed. The weight, multiplied by two, expresses the percentage of precipitated phosphate of lime, which may contain, also, some possible trace of free carbonate of lime. n. Carbonate of Lime. The filtrate from the preceding filter is to be treated with oxalate of ammonia, until a precipitate or cloudiness ceases to form. The CHE MICA L A NA L Y SIS. 483 oxalate of lime is then to be filtered off, washed, dried, ignited, and weighed. As oxalate of lime changes into carbonate by ignition, the weight, doubled, represents the per cent, of carbonate of lime in the sample. o. Organic Matter. The filter j having been thoroughly dried at 212° Fahrenheit, its contents are then weighed and afterwards calcined in a plati¬ num crucible. The loss of weight thus produced by igni¬ tion represents the amount of organic matter in the sample. p. Sand and Silica. The remaining calx is now to be treated with hydrochloric acid, and carried through the operations explained at length in para¬ graphs 3, 4, 6, 7, 8, 9, 10, 11, and 13 of the first formula of this chapter. In this manner, each and every one of its probable constitu¬ ents will thus be detected and estimated. The formula just given is made compre¬ hensive, so that it may apply in the first part to commercial superphosphates of lime, and i 1 2 484 PURE FERTILIZERS . in its entireness to any and every fertilizing mixture of artificial manufacture, however complex. The constituents having been separated and quantitatively determined, should be formulated according to the following ar¬ rangement. Recapitulation . Soluble bi-phosphate of lime - Precipitated phosphate of lime Bone- or tri-phosphate of lime Bone-phosphate of magnesia - Chloride of ammonium - Chloride of potassium - Chloride of sodium - Sulphate of ammonia - Sulphate of potassa - Sulphate of soda - Nitrate of soda - Sulphate of alumina - Sulphate of iron - Phosphate of alumina - Carbonate of lime - Lime, with organic and silicic acids and alumina - Fluoride of calcium - Alumina - Oxide of iron - Sand and silica - Organic matter - Water - Total CHAPTER XXIV. ON THE COMMERCIAL VALUATION OF CRUDE AND REFINED FERTILIZING MATERIALS. In computing the value of a fertilizing mate¬ rial there should be a close adjustment of its commercial and agricultural relations. The prime elements of a profitable ferti¬ lizer are nitrogen, phosphate of lime, and potassa. To determine, however, the com¬ mercial and agricultural worth of a fertilizing material, it is necessary to ascertain its pre¬ cise composition and nature by a full chemi¬ cal analysis. The questioning, in this re¬ spect, must be both scientific and conscien¬ tious ; for no mere partial investigation will serve the importance of the subject. Not only must it be learned what constituents are present, but in which forms they exist and with what associates they may be accom¬ panied. 486 PURE FERTILIZERS. In a general sense, the form or state regu¬ lates the agricultural value of a fertilizing element ; but the character of its associates affects, more or less, the computation. Ammonia. Thus, as to azotized matters, those which contain their nitrogen in the form of ammo- niacal salts are the most active; while others, on the contrary, like woollen waste, horn, and leather clippings, which contain it in a com¬ paratively dormant or quiescent state, acquire chemical or fertilizing momentum, so to speak, only by the aid of time and decompo¬ sition. These influences add to the first cost and change the classification or money rank of the material. Here, moreover, sub¬ stances of this kind which are most prone to decomposition, are worth more, proportion¬ ally, than others of their class. Intermediate between these two, is a third form existing as urea, urate, and phosphate, in farm-yard manure, bird guanos, human excrements, and kindred substances ; which, though not active or dormant, are more potential than either. I use this term, potential, to desig- COM ME R CIA L VA L UA TION. 487 nate a great sensitiveness to the assimilating powers of the growing crop, whereby the plant is enabled to take up its nutriment in condition and quantity as may be wanted to produce the highest degree of progressive development with the least possible expendi¬ ture of time and fertilizer. This form of nitrogen being the most valuable, in every sense, should constitute the standard of esti¬ mation ; but, unfortunately, the supply of it is too limited, at present, to justify that posi¬ tion for it. Later, when its source becomes amply extended by the separation of the organic matter from the phosphate-sewage precipitate, as suggested at pp. 397 to 405, it may assume the controlling position in the appreciation of nitrogenous substances. In the meantime, there remain only the ammonium chloride and sulphate as a solid standard of comparison. The abundant and regular production of crude ammonia liquors in the coal-gas and bone-black works, render those salts, already, the most prominent part of the ammonia supply ; and this source not only assumes a progressive increase, but is becoming widened by lateral feeders from the 488 PURE FERTILIZERS . utilization of woollen wastes for the purpose. Not long hence, it will expand into yet larger proportions, when the excrements of mankind are turned into this account or cur¬ rent, after the manner which I have noted at p. 47 ; or the air is exploited for the purpose. With this explanation, therefore, ammonia must be set down at its average value in ammonia salts, which is ^90 per ton or 18s. per unit ; the present market price of ammonium chloride being ^30 per ton, while that of sulphate of ammonia is £22 per ton. Materials containing nitrogen in a dormant or quiescent state are to be rated at a figure so much less as will cover the manufacturing expense of converting that nitrogen into its equivalent of ammo¬ nia salt, with twenty per cent, superadded for profit and contingencies. The unit refers to the ton of 2240 pounds, and is used in accordance with the prevailing British custom, which requires that the com¬ putation shall be made by unit rather than by per cent. Every per cent, of any constituent of a material, when multiplied by twenty, becomes COMMERCIAL VALUATION. 489 a unit. Thus, for example, if a material should contain seventeen per cent, of ammo¬ nia or the equivalent in nitrogen, with the cost of conversion added, it is said to have 17 units of ammonia, although the latter represents in fact 380 pounds of ammonia in the ton of the material. The method of calculating by per cent, is, however, the more rational one, as it gives expression to the actual quantity or propor¬ tion of the valuable constituent of a raw material. On the other hand, the unit method excludes from the computation 240 pounds of the ton, as a concession to trade influence. Phosphates of Lime. Bone-ash or animal phosphate of lime is the typical expression of this material ; and pure apatite and phosphorite may be taken as the best representatives of its mineral condition. Animal Phosphate of Lime. Bone-ash has a peculiarly sensitive tem¬ perament in its chemical relations, and is 490 PURE FERTILIZERS. well suited for immediate potential effect upon soils. It is more uniform in composi¬ tion than any other kindred material, and contains a higher average of actual phosphate of lime. Moreover, in this material there is only an inconsiderable proportion, compara¬ tively, of profligate matters associated with the phosphate of lime constituent. On these accounts it holds a commercial and agricultural position apart from other kinds of its class. The laws of supply and demand regulate, therefore, its market price, which is at present £6 : 15 to £j per ton, or 2s. per unit. This value refers to ash con¬ taining 70 per cent, of tri-phosphate of lime, that being the usual strength. Bone-black and bone-dust are to be esti¬ mated by the above standard, for similar reasons, but according to the proportion of tri-phosphate of lime which they may con¬ tain. At the same time, their content of nitrogenous matter must be taken into con¬ sideration. This is potential in character, and its money value is to be computed, as explained already under ammonia, and added to that of the phosphate constituent. COMMERCIAL VALUATION. 491 Mineral Phosphate of Lime. The mineral phosphates of lime, even of the highest grade, have a dense structure and rocky nature, which give them a chemical, as well as physical temperament, quite distinct from that of bones, bone-ash, or bone-black. Moreover, a greater or lesser quantity of the phosphoric acid which they may contain is combined, almost invariably, with iron and alumina ; whereas, the animal phosphate of lime holds that acid wholly as tri-phosphate of lime. The presence, too, of foreign asso¬ ciates with the lime phosphate element is an important modifying influence in deter¬ mining the commercial value of a mineral phosphate. I restrict my remarks to the commercial value because mineral phosphates in their natural crude state are very slow indeed as direct agricultural agents. The foreign mat¬ ters which they contain exert a cementing action upon the valuable phosphate of lime constituent, and thus impart to this latter an inertia which militates against its fertilizing activity. Though vegetation will draw its 492 PURE FERTILIZERS . nourishment from the most available source, however difficult, its vigour of structure and productive capacity will be more or less feeble if the nutriment should be either de¬ ficient in quantity or obstinate to the atmo¬ spheric and solvent influences of the soil. Plants thrive best when their food is present in assimilable or potential forms ; and, con¬ sequently, time and money are both wasted in sowing fertilizers which may be tough in nature or sluggish in action. The phosphate of lime constituent re¬ quires, therefore, to be separated from its disadvantageous association of foreign mat¬ ters ; and this involves the expense of chemical agents, labour, time, etc. The foreign matters, to say the least, are unprofitable diluents of the phosphate of lime constituent. Indeed, their presence in mine¬ ral phosphates is an injurious influence of important degree. Apart from their cement¬ ing action, they have the disadvantage of importing into the products a humid pro¬ perty and a large degree of dilution, without any compensating advantage whatever, when the crude mineral is treated with acid for COMMER CIA L VA L UA TION. 493 conversion into pure phosphates of lime. They not only waste acid in this manner, but really are barriers to its free action upon the phosphate of lime constituent, as the latter remains intact until the associate matters have been overcome chemically. As promoters of waste and excessive dilu¬ tion, I term these foreign matters profligate elements or associates; and they consist of fluoride of calcium, carbonate of lime, organ- ate and silicate of lime, oxide of iron and alumina, in first degree; and of sand, silica, and organic matter, in secondary importance. Pure tri-phosphate of lime, divested of all associates passive in themselves, or which might paralyze its fertilizing action, is, there¬ fore, the only sound basis for computing the value of a crude phosphate of lime. There is no such standard in Nature, practi¬ cally considered ; but if one should be found, it would be worth double the market value of a mineral containing only 50 per cent, of tri¬ phosphate of lime, plus the cost of the acid, labour, and manufacturing expense which the residual moiety of profligate elements would entail in the conversion of two tons of 494 PURE FERTILIZERS . such crude material into the one ton of pure phosphate. As the per cent, of phosphate of lime falls, that of the profligate associates rises ; and hence the convenience and expense of re¬ fining a crude mineral are dependent upon the prevailing circumstances in this respect; and, correspondingly, the value will progress downwards or upwards in regular arithmeti¬ cal proportion. The medium grades of mineral constitute the major part of the crude phosphate re¬ sources, and, being unsuited for fertilization until they have been chemically prepared, it follows that the basis for computation must be selected from them. And, as seems to me most justifiable, I take one containing 45 per cent, of actual tri-phosphate of lime, the present market value of which is tenpence one farthing per unit, or thirty-eight shillings and sixpence per ton. This kind of mineral phosphate of lime has expression in the Wicken and Calais Coprolites, and the best quality of “ South Carolina Phosphate ’. Taking, then, a crude mineral of 45 per cent, of lime phosphate strength, at its pre- COMMER CIA L VA L UA TI ON. 495 sent market value of £/\. : 5 for 2*20 tons, the only datum that is needed to form a table of the money value of different grades of raw phosphate is the mere expense for chemicals, labour, fuel, etc., which would be consumed for refining that quantity of crude mineral into its equivalent of ro ton of pure or standard phosphate of lime. This would be ^5 : 15, according to my experience, and must be dis¬ tributed, therefore, through all the degrees from 45 to 100 of the scale, in order to ex¬ press a correct graduation of the value. There are, consequently, fifty-five degrees which are to share the amount which is to be apportioned ; and, as the ratio of phosphate may rise degree by degree, in the raw mine¬ ral, each degree will hold not only its original value of tenpence farthing per unit, but an additional one acquired by the saving of the refining expense which, otherwise, would be involved by displacing its equivalent of pro¬ fligate elements. Starting, therefore, at tenpence farthing per unit for a raw mineral containing 45 per cent, of actual tri-phosphate of lime, there must be a progressive advance of one 49^ PURE FERTILIZERS . farthing for each degree, so that when the natural quality of the mineral may have risen to purity, as in some specimens of apatite, it will represent a value of two shillings per unit. In like manner, the scale may be carried downwards by diminishing the valuation, progressively, a farthing for each degree of actual phosphate of lime strength ; but, for manufacturing purpose, the mineral should not have less than twenty-four degrees, in that respect. In other words, mineral phosphates cease to be profitable when they contain less than 24 per cent, of actual phosphate of lime. The following table is founded upon this basis, and refers to the actual per cent, or degree of phosphate of lime , because it is my habit always to distinguish that portion of phosphoric acid thus united from that which may be combined with the oxides of iron and aluminium that are present, and for the simple reason that the latter is, agriculturally, much inferior in value to the former, and should be estimated separately. This explanation is rendered necessary by the fact that analyses of mineral phosphates 497 V COMMERCIAL VALUATION. arc made often in a “ commercial ” style most discreditable to science and the chemical profession. Not only are incongruous con¬ stituents grouped together, in the report, under one head ; but the total of phosphoric acid is expressed most frequently by its equi¬ valent in tri-phosphate of lime, as if there were no other phosphate present: and when, in fact, much of the phosphoric acid is com¬ bined actually and less profitably with alu¬ mina and oxide of iron. Such a presentment implies a character which is unreal, and practises a deception which is mean. Science, in its dignity, is regardless of all interests but those of truth and humanity. Its mission is to serve the good of mankind, and not the profit of an individual or class. The chemist, then, in his professional quality, is a high priest of science, who assumes, as a trust, the obligation of administering its rites with¬ out fear or favour in respect of results or persons ; and, in betraying this confidence, he becomes not only a false prophet, but deposes himself by the act from his sacred office. k x 498 PURE FERTILIZERS. Mor fit's Table of the Vahte of Crude Phosphates of Lime of Different Grades. Per cent, of actual tri¬ phosphate of lime. Per cent, of profligate associates. Value of the raw mineral per unit of tri-phos¬ phate of lime. Per cent, of actual tri¬ phosphate of lime. Per cent, of profligate associates. Value of the raw mineral per unit of tri-phos¬ phate of lime. S. D. F. S. D. F. 45 55 O IO I 73 27 I 5 I 4 6 54 O IO 2 74 26 I 5 2 4 7 53 O 10 3 75 25 I 5 3 4 s 52 O I I 0 76 24 I 6 0 49 5 i 0 I I I 77 23 I 6 1 50 50 O I I 2 78 22 I 6 2 5 i 49 O I I 3 79 21 I 6 3 52 48 I O 0 80 20 I 7 0 53 47 I O I 8 1 19 I 7 1 54 46 I O 2 82 18 I 7 2 55 45 I O 3 83 1 7 I 7 3 56 44 I I 0 84 l6 I 8 0 57 43 I I I 85 15 I 8 1 58 42 I I 2 86 14 I 8 2 59 4 i I I 3 87 x 3 I 8 3 60 40 I 2 0 88 12 I 9 0 61 39 I 2 1 89 11 I 9 1 62 38 I 2 2 90 10 I 9 2 63 37 I 2 3 9 i 9 I 9 3 64 36 I 3 0 92 8 I 10 0 65 35 I 3 1 93 7 I 10 1 66 34 I 3 2 94 6 I 10 2 67 33 I 3 3 95 5 I 10 3 68 32 I 4 0 96 4 I 11 0 69 3 i I 4 1 97 3 I 11 1 70 30 I 4 2 98 2 I 11 2 7 i 29 I 4 3 99 1 I 11 3 72 28 I 5 0 100 0 2 0 0 COMME R CIA L VA L UA TION. 499 Precipitated Phosphate of Lime . This being a pure, or nearly pure, product eliminated from the raw mineral phosphates at great expense, is much more valuable than any corresponding grade of natural phos¬ phate of lime. Being very sensitive to the atmospheric and solvent influences of the soil, it represents the potential condition of its class. In making the preceding table, only the bare expense of materials and manufacture, without margin for profit, was added to the first cost of the raw minerals, in order to fix the value of different grades of natural phosphate. For the reasons above noted, however, and also because there is a great economy secured, as to package and transportation charges, in connection with the pure concentrated artificial product, its value would be fairly computed by adding fifty per cent, to the figures noted in the table for natural phosphates. In other words, pure precipitated phosphate of lime has an actual worth of three shillings, at least, per unit. As it is inexpedient to dry out all its moisture, the presence of water, even to the 5 oo PURE FERTILIZERS . extent of ten per cent., should not be con¬ sidered an impurity to degrade its quality and rating ; which latter, however, refers here to the anhydrous state. Colombian Phosphate of Lime. This form of precipitated phosphate of lime contains more or less di-phosphate, and, consequently, has a higher degree of potenti¬ ality. Its value is, therefore, greater, and will be fairly computed by calculating its total of phosphoric acid to lime, and esti¬ mating the equivalent of tri-phosphate of lime, thus deduced, according to the rule prescribed above for precipitated phosphate, —that is, at three shillings per unit. Di-phosphate of Lime. This phase of phosphate is met with only occasionally in Nature. In such instances, its phosphoric acid must be calculated to lime as tri-phosphate, and the equivalent thus deduced is then to be rated according to the table at p. 498. The artificial product requires a different consideration. By reason of its chemical MOR.Fl T on the Ma nnfartwre of Fertilizers. COMMERCIAL VALUATION. 501 tenderness, it is in the same category for potentiality as the Colombian Phosphate, but in higher degree. Though the cost of its preparation is not greater than that of the Colombian Phosphate, it contains a much larger ratio of phosphoric acid, and, there¬ fore, must be estimated accordingly. The proper way to determine its value will be to calculate its content of phosphoric acid to lime as tri-phosphate, and value its equiva¬ lent of the latter at three shillings per unit. As it contains about six and a half per cent, of constitutional water, and may hold, advantageously, as much more of accidental moisture to insure impalpability of powder, 10 to 15 per cent, of water should not be allowed to disturb the valuation above given. Indeed, a product which does not contain more than 10 per cent, of water and 10 per cent, of foreign matter is pure for all practical purposes. Bi-phospliate of Lime. The processes for making pure precipi¬ tated or di-phosphate of lime are so simple, economical, and advantageous, in all re- 502 PURE FERTILIZERS. spects, that I do not recognize any other materials as a proper basis for the manufac¬ ture of bi- or superphosphate of lime. My views on this point have been set forth already in Chapters xm and xiv. It is only necessary to remark now, that either precipi¬ tated, Colombian, or di-phosphate will yield a “ superphosphate” of the highest possible quality at even a lower cost than the cheapest of crude mineral phosphates when great purity, concentrated form, and economy of packing and transportation are considered. The “superphosphate” of promiscuous composi¬ tion, therefore, as made from mineral phos¬ phates (often carrying 90 per cent, of worth¬ less matter, and even at the best, when pre¬ pared from good bone-ash, never richer than 30*0 per cent, of anhydrous bi-phosphate of lime), is being pushed into merited disrepute by the chemical improvements of the day in connection with this subject. As made from the pure sources, “ super¬ phosphate" will contain nothing but the chemical equivalent proportions of bi-phos¬ phate and sulphate of lime which rightly be¬ long to it. Its value, therefore, will be the COMMERCIAL VALUATION. 503 first cost of the precipitate, plus that of the quantity of sulphuric acid required to convert it into bi-phosphate, with 10 per cent, added for profit. Thus,— 100 tons of pure precipitated phosphate of lime - ^1500 82 „ brown oil of vitriol of specific grav. 1700 287 Manufacturing expenses, profit, etc. - 150 £1937 The product is, quantitatively, 190 tons of “ superphosphate", containing, practically, 39 to 40 per cent, of actual bi-phosphate of lime, or CaO, 2HO, PO 5 . As commercial “ super¬ phosphate", therefore, it is worth, say per ton, or five shillings per unit of actual bi-phosphate of lime. I have estimated the bi-phosphate of lime, with its constitutional water, as part of its formula, and for the reason that this water is an element of its nature, which cannot be alienated without modifying the properties of the original bi-phosphate disadvantageously. Pure Bi-phosphate of Lime. This salt is made from the preceding “superphosphate" by merely leaching it in water and evaporating to crystallization the 504 PURE FERTILIZERS . solution of bi-phosphate thus obtained, ioo tons of precipitated phosphate of lime give 75 tons of pure bi-phosphate, at a cost of ^1987, plus 10 per cent, for manufacturing expense. This makes a total of £ 2200, which, divided by 75, gives ^30 as the value per ton, or six shillings per unit of pure bi-phosphate of lime = CaO, 2HO, P 0 5 . The usual commercial custom is to estimate the anhydrous bi-phosphate as equivalent to tri-phosphate of lime; and, by this means, 0*641 is made to appear as roo per cent. Such a valuation is fictitious, and could not be evolved under a just system of computa¬ tion. My figures will refer, therefore, to the actual bi-phosphate of lime as it exists, naturally, in the “ superphosphate” or pure bi-phosphate of lime, according to the for¬ mula CaO, 2HO, P 0 5 . Di-phosphate requires less acid than the precipitated phosphate of lime for its conver¬ sion into “ superphosphate”, but the product from it is much smaller, and this incident makes the two correspond closely in value as raw material for conversion into superphos¬ phate. But, as the “ superphosphate’’ from COMMER CIA L VA L UA TION. 505 di-phosphate of lime would contain a greater per centage of bi-phosphate than that made with precipitated tri-phosphate, a given weight of a product from the former will be worth more than a corresponding quantity of product from the latter. Degree and de¬ gree, the bi-phosphate from either source has the same value, which is five shillings per unit. But for the obstinate popular prejudice in favour of “super-” or “bi-phosphate”, di¬ phosphate would come into general use as a substitute for them. It is much more econo¬ mical and fully as potential, if not quite as active, in fertilizing effect. Indeed, it is more than probable that most of the bi-phos¬ phate, which may be sown, “goes back ” into di-phosphate long before the growing crop has had time to take it up and assimilate it. Phosphate of Magnesia. This is to be estimated according to its ratio of phosphoric acid and after the rules prescribed for the phosphates of lime, ac¬ cording as it may be in a mineral or arti¬ ficial state. 506 PURE FERTILIZERS. Phosphate of Alumina. This salt, in its natural rocky state has only a commercial value; and, as “Alta Vela Guano” is the sole representative of its class, which comes to market at present in abun¬ dant and regular supply, it must be taken as the standard at the current price of : io per ton of 35 0 phosphate strength, or one shilling per unit of phosphoric acid which it may contain. As the proportion of phospho¬ ric acid may fall, that of the alumina and foreign associates must rise ; and, conse¬ quently, the less valuable becomes the mine¬ ral. Owing to the uncertain composition of the phosphate of alumina as existing in this kind of mineral, the system of computing the value of the latter will be somewhat arbi¬ trary. It may be wholly meta-phosphate of alumina (Al 2 03, 3 P 0 5 ), or a mixture of that and pyro-phosphate (2A1 2 0 3 , 3P0 5 , 10HO), when dried at no°, together with more or less of free alumina. In any case, the greater the presence of alumina, the larger will be the quantity of acid required for the chemical treatment which it must undergo to become COMMERCIAL VAL UA TION. 507 serviceable in agriculture or the arts. There¬ fore, the value of this class of minerals is to be gauged according to the content of alu¬ mina and the composition and cost of the “ Alta Vela Guano” at the present market price or rate. But it is not difficult to make a scale upon this basis, for the presence of a very large quantity of constitutional water in most cases excludes any appreciable amount of foreign or profligate matters. The small margin thus left for the latter constituents is almost wholly filled by silica and oxide of iron. There is, therefore, no disturbing ele¬ ment of calculation, but the variableness of the ratio of alumina to the phosphoric acid. Assuming, then, as a starting-point, that the value of a mineral phosphate of alumina is one shilling per unit, when the ratios of alumina and phosphoric acid are as 33 to 31, and that there are no profligate constituents, for example, as in the “Alta Vela Guano”; then, for every gradation of the former down¬ wards, there will be a proportional rise in the value of the mineral. Thus, it is only neces¬ sary to calculate the actual cost of removing the alumina degree by degree, in order to 508 PURE FERTILIZERS. determine the improvement in value for pro¬ gressively augmenting ratios of phosphoric acid. Mor fit's Table of the Commercial Value of Different Grades of Mineral Phosphate of Alumina. Ratio of alumina. Ratio of phospho¬ ric acid. Value unit per Ratio of alumina. Ratio of phospho¬ ric acid. Value per unit. S. D. F. S. D. F. 22'0 310 I O 0 17-0 3 no I 8 3 2 I 'O 3 no I I 3 1 6-o 3 no I 10 2 20'0 3 no I 3 2 15-° 3 no 2 1 0 I9‘0 3 no I 5 1 I4-0 3 no 2 3 0 l8o 3 no I 7 0 — — - A range has been given to these computa¬ tions which will comprise all the kinds of this mineral now known even by specimens only. As, however, the figures affixed refer exclusively to the phosphate of alumina in its crude state, there remains yet to explain the values of the phases of artificial phos¬ phate of alumina as made in the phosphate- sewage process (Chapters xx and xxi), or other method of precipitation from an acid solution of the raw mineral. Here the same principles come into play as for the precipi- CO AIMER CIA L VA L UA TION. 509 tated phosphate of lime. The original rocky character of the mineral has changed to a soft pulpy condition, most tenderly sensitive to acids, alkalies, and the growing influences of vegetation ; so that, in fact, a new physical nature has been assumed. As, however, the chemical composition of the precipitate will not differ materially from that of the alumina phosphate constituent of the original mineral, the values of the different grades will be fairly expressed by adding twenty-five per cent, to the several degree-computations of the preceding table. Phosphate of Iron. The values of the different grades of this constituent, whether natural or prepared arti¬ ficially, can only be estimated arbitrarily, but may safely be taken at half the rates com¬ puted for phosphate of alumina. In either of the two preceding cases the valuation refers to the purposes of sewage- defecation, the alum manufacture, and agri¬ culture ; for it will be seen in Chapters xvm, xix, xx, and xxi, that both the phosphate of alumina and phosphate of iron are capable of 5 10 PURE FERTILIZERS . many and profitable applications. Indeed, this wide range of practical usefulness makes the commercial appreciation of the phos¬ phates of alumina and iron much greater than their agricultural value. The remaining items pertaining to this subject are chlorides of potassium, sodium, and ammonium ; sulphates of potassa, soda, and lime ; nitrate of potassa and nitrate of soda, each of which has a current value varying with the supply and demand, as may be learned by reference to any market price¬ list of the day. CHAPTER XXV. THE MODE OF USING HYDROMETERS AND THERMOMETERS. A hydrometer is a convenient glass instru¬ ment for measuring the density or specific gravity of fluids. It is often referred to throughout this work; for instance, in speak¬ ing of an acid, the strength is stated as being of so many degrees Baume or Twaddle; that is, it has a specific gravity correspond¬ ing with the degree to which the hydrometer sinks in the liquid. For those liquids lighter or rarer than water, viz., alcohol, ethers, and the like, the scale is graduated differently than for the heavier or more dense, examples of which latter are the acids, saline solutions, and syrups. There are several kinds of hydro¬ meters ; but that called Baume s is the most used, and to this my remarks will refer. 512 PURE FERTILIZERS. The scale for the liquids rarer than water is graduated upwards from o, at the bottom of the stem, as shown by fig. 21. For liquids denser than water, the graduation is reversed, as in fig. 22. As it would be troublesome, and with many impracticable, to estimate the specific gravities of liquids in a scientific way, these little instruments are a great convenience ; for, by taking out a portion of the fluid to be tested, and placing it in a tall glass cylinder (fig- 23), its degree Baume may be ascer- HYDROMETERS & THERMOMETERS. 513 tained by noting the point to which a hydro¬ meter sinks therein. From this datum its specific gravity is deduced by calculation, according to the proper formula on p. 514. For instance, suppose the hydrometer sinks in alcohol to 35 0 , then its specific 5 i 4 PURE FERTILIZERS. gravity is 0*852, and this again can be translated into its absolute spirit strength by comparison with any accurately calculated alcohol table. So, also, if a hydrometer for liquid denser than water sinks in acid to 66°, it denotes that the acid has a specific gravity of 1 ‘846. The presence of foreign matters will cause the hydrometer to give a false indication, but for nearly pure liquids the instrument answers satisfactorily; and, indeed, under all circumstances, it serves very well for noting a progressive increase or diminution in the strength of solutions or other liquids. The temperature of the liquid should be 6o° to 62° Fahrenheit, at the moment of testing it. The following rules, by Pile, in connection with hydrometers, will be found convenient: To convert Baumes degrees into specific gravity numbers . For liquids lighter than water. B° + n 4 = s P ecific gravity. To convert specific gravity numbers into Baumes degrees . For liquids lighter than water. 144 Sp. grav. HYDROMETERS & THERMOMETERS. 515 To convert Baumes degrees into specific gravity numbers. For liquids heavier than water. T 44 -r 144 - b ° = s P ecific s ravit y- To convert specific gravity numbers into BaumTs degrees. For liquids heavier than water. 144-= B°. sp. grav. Eor converting the degrees of Twaddle s hydrometer into specific gravity numbers multiply by 5, and add rooo; thus— Twaddle °8o° X 5 =400 + 1000 = sp. grav. 1-400. For converting specific gravity numbers into the degrees of Tzvaddles hydrometer deduct rooo, and divide by 5 ; thus— Sp. grav. 1*400- 1000 = = Twaddle 8o°. Vulcanite is now substituted, sometimes, for glass, in the manufacture of hydrometer and thermometer scales. Such instruments are much more durable in every respect. They may be purchased at Blaise and Co.’s, No. 67, St. James’s Street, London. Thermometers. The thermometer is an instrument made wholly of glass, when intended for chemical L L 2 5 i6 PURE FERTILIZERS. f»r- 24 - purposes. Fig. 24 shows one with the scale graduated upon porcelain en¬ amelled upon the tube, so that the de¬ grees may be easily read and the in¬ strument readily kept clean. It is a measurer of the variation of tempera¬ ture in bodies.. The principle upon which it is constructed is the change of volume which takes place in bodies when their temperature undergoes an alteration, or, in other words, upon their expansion. In the construction of thermometers, the fluid employed for measuring the change of tempera¬ ture is usually metallic mercury, be¬ cause it expands uniformly and has a very wide interval between its freezing and boiling-points. There are several different thermo- metrical scales, all constructed upon the same principle, but varying in their graduation ; the boiling and freezing- points of each, though corresponding in fact, being represented by different numbers. The Fahrenheit scale is most used HYDROMETERS & THERMOMETERS. 517 in this country; that of Celsius, called the centigrade, in France and the continent generally, except Spain and Germany, where Reaumur’s scale is preferred. In the Fahrenheit thermometer, the inter¬ val between the freezing and boiling-points of water is divided into 180 degrees. The freezing-point is placed at 32°, and hence the boiling-point at 32+180=212°. Reau¬ mur divides the distance between the two extreme points of water into 8o°, and Celsius spaces his thermometer (the Centigrade) into 100 equal intervals, the zero point, as in Reaumur’s, being placed at freezing. The Fahrenheit scale is most convenient, be¬ cause of the lesser value of its divisions; but, as it frequently happens that the manu¬ facturer has no choice in the kind, but is compelled to take such as can be con¬ veniently obtained, I give formulae for con¬ verting the degrees of one into those of the others. In the graduation of the scale it is only necessary to have two fixed determinate tem¬ peratures, and for these the boiling and freezing-points of water are universally 5 i 8 PURE FERTILIZERS. chosen. The scales can be extended beyond either of these points by continuing the graduation. Those degrees below zero or o° have the minus (—) prefixed, to distin¬ guish them from those above: thus 55 0 F. means fifty-five degrees above zero, Fah¬ renheit’s scale ; and —9 0 C., nine degrees be¬ low zero, centigrade scale. The thermome¬ ters for general use, very seldom, however, extend either way beyond the boiling and freezing-points of water, but they are gra¬ duated sometimes to 400° or 6oo°. One of 300° Fahrenheit is cheaper and con¬ venient for general manufacturing purposes. The following rules will be found con¬ venient for converting the degrees of the several scales into each other:— To convert Centigrade into Fahrenheit degrees . Multiply by 9, divide by 5, and add 32 . To convert Centigrade into Reaumur de¬ grees. Multiply by 4, and divide by 5. HYDROMETERS & THERMOMETERS. 519 To convert Reaumur into Fahrenheit de¬ grees. Multiply by 9, divide by 4, and add 32. To convert Reaumur into Centigrade de¬ grees. Multiply by 5, and divide by 4. To convert Fahrenheit into Centigrade degrees. Deduct 32, multiply by 5, and divide by 9. To convert Fahrenheit into Reaumur de¬ grees. Deduct 32, multiply by 4, and divide by 9. CHAPTER XXVI. WATER AND ACID-PROOF CEMENTS AND PAINTS. In the construction of mason-work for che¬ mical purposes, it is necessary that the cement employed shall be not only strong and durable, but proof against the action of water ; and, if possible, also resistant of the action of acids. The following means are the best known for accomplishing those re¬ quirements. Hydraulic Cement . The Portland Cement, as made in London and its vicinity, fulfils all these requirements, except the last, in more eminent degree than any other; and it is best to employ that kind. Without intending to discuss princi- DURABLE CEMENTS AND PAINTS. 521 pies* which regulate the hydraulicity of cements, I will remark that the lime which is to be used for works which are to resist the action of water, must be made of a lime¬ stone containing a certain amount of clay and magnesia with some little manganese and iron. The proportion of these ingre¬ dients combined should bear the relation of 20 to 30 per cent, of the carbonate of lime constituent. In a lime-stone of such a com¬ position the soluble silica, alumina, and magnesia, will be most likely to hold that proportional relation to the lime which seems necessary to a prompt and complete hydrau¬ licity of a cement. If there should be an excess of lime over and above the chemical proportion required to form the triple silicate of lime, alumina and magnesia which constitutes a good hy¬ draulic or water-cement, it would in time be washed out gradually by the water; but the * According to Fremy, aluminate of lime plays a most important part in the hydraulicity of cements; and he has reported the results of his researches on the subject, in the Journal de Pharmacie ct de Chirnie , at p. 20 of vol. 2 for 1865. 522 PURE FERTILIZERS . cement will remain hard, and unimpaired in strength and durability. In the event of there being no excess of lime, the silicate formed by mixing the cement with water will be so closely bound as to its constituents, that it will resist to a considerable degree even the decomposing action of acids. A very good hydraulic cement may be made according to the following formula. The ingredients are—best quality fat lime, 68 to 74J parts by weight ; refractory clay, 27q to 42f; sulphate of lime, 4f to 9*0 ; and boracic acid, 0*105 to 0*401. All the substances are calculated in the anhydrous state. The cements formed be¬ tween these limits vary in the rapidity with which they set, but are of equal quality, and attain, in the course of time, the same degree of hardness. The substances are mixed after being ground to a fine powder. They are then made into bricks with water, and are baked at a white heat. After this, they are reduced to an impalpable powder. This powder, mixed with water, is then used as the cement, either plain or coloured, and can be moulded as required. DURABLE CEMENTS AND PAEVTS. 523 B'dttgers Cement . This is a very good cement for sealing joints. It is made by mixing finely-powdered chalk with an aqueous solution of silicate of soda, of 33 0 Baume, so as to form a stiff mortar. It sets hard in six to ten hours. Sorels Cement . This is a very hard cement, and will serve for sealing the joints of mason-work. It is a hydrated basic oxychloride of magnesium, prepared by mixing calcined magnesia with an aqueous solution of chloride of magne¬ sium of 20° to 30° Baume. The denser the solution, the harder will be the cement. Bituminous Cement , or Stearic Bitch. When the digester vats are built, they may be lined with the preceding cements if intended for solutions of a neutral character. But for operations of an acid nature they must be covered with a cement or paint of thorough protective power against the chemi¬ cal friction of acids. This coating must also 524 PURE FERTILIZERS\ have a high softening-point, more particu¬ larly where heat is to be used in the vessels painted with it. The material fulfilling more nearly than any other all these requirements, is the black pitchy residue obtained in the distillation of fats for the manufacture of stearic candles, and in the refining of ‘'cotton oil foots”. It is black, insoluble in water and acids, and retains its hardness so obstinately, that it is difficult to melt it alone at a temperature be¬ low 300° Fahrenheit. Being a refuse article, its market price is very low. In order to fuse it, a particular apparatus is necessary, as shown by Plate 28. It con¬ sists of a strong jacketed pan a a, made of wrought iron plate, and set in brick-work. This pan is heated by steam, which enters the jacket through the pipe b. The con¬ densed steam runs out through the tube c, which, during the heating, must be kept partly open by means of a cock as a safety- valve. The stirrer d is a wrought iron shaft rest¬ ing in a footstep at the bottom of the pan. Its blades or arms are of two kinds : the DURABLE CEMENTS AND PAINTS. 525 lower ones being a series of loose scrapers of forged iron eee , and c strung upon a rod f. This arrangement insures the scraping of the bottom of the pan and prevents accumulation of lumps of bitumen upon the heated surface of that portion of the metal; while, at the same time, it is a protection against break¬ age, which might happen often, if the blade were more stiff, from the obstinate tenacity with which the pitch adheres to the metal when it is only partly melted. The upper blades gg, are made of a form to produce agitation of the contents of the pan, and also to scrape the sides, so as to keep them clean of adhering pitch. The stirrer is driven by steam, through means of the gearing h, affixed to a beam above. The pan, as shown by the plate, has the capacity for melting five hundredweight of pitch at each operation ; and four meltings may be made in twelve hours. The temperature required to effect the fusion being about 310° Fahrenheit, and, as the generator would have to be heated up to a pressure of sixty-five pounds per square 526 PURE FERTILIZERS. inch, in order to give steam of that degree, it will be safer and more convenient to use a super-heater, as an auxiliary means. This apparatus, of inexpensive form, shown by o, at the side of the pan, consists of a coil made of very thick welded iron tubes k k, and put together by joints. The connections with the generator are shown at and with the pan at n. The whole is set in brick-work, with a furnace beneath, and this latter has a damper- arrangement for the management of the heat, according as steam of a moderately or very high temperature may be required. A little boiled linseed-oil will facilitate the fusion, but the addition of this fluid must be limited to ten per cent, of the pitch, for fear of lessening the hardness of the product. When the whole is fused and has become quite cold, it is to be thinned with spirits of turpentine or petroleum naphtha to such con¬ sistence as may be required. When the pitch is to be used as a cement it must be applied in its hot fluid state, and as thick as possible; for which purpose, con¬ sequently, it should not contain any spirits DURABLE CEMENTS AND PAINTS. 527 of turpentine. It takes several days to dry when mixed with oil alone ; but this objec¬ tion is countervailed by advantages. In this form it covers iron well with a coating which is very adhesive, though not even. To make an even coating, turpentine must be added, so as to thin the cement to the consistency of a paint, which may be applied readily with a brush. As the drying is very rapid, several suc¬ cessive coats may be put on in a day. This latter paint, applied thick and in several coats, is the protecting covering for iron and other vessels, which has been pre¬ scribed throughout this work. It may be made even without the aid of linseed-oil or the super-heater, by means solely of turpen¬ tine and at the ordinary temperature of the atmosphere. Vessels coated with this material will re¬ sist the action of acid liquors at temperatures even beyond 225 0 Fahrenheit. Marine Glue. This cement, which is proof against the action of both water and acids, may be made 528 PURE FERTILIZERS . by heating gently one pound of india-rubber with twelve pounds of coal-tar, mixing thoroughly, and then adding and melting in twenty to twenty-four pounds of powdered shellac. The whole is then to be dipped out, and poured on a slab to cool. When used, it requires to be heated above 250° Fahrenheit. This cement is much more expensive and less advantageous than that made with the*' pitch from fats. Too frequent remelting spoils it. Substitute for Marine Glue. A good water and acid-proof cement may be made by melting together equal parts of gutta-percha and pitch, and casting into sheets or sticks on a plate. It may be made hard or soft by using less or more of gutta¬ percha. Cement to Resist Sulphuric Acid . Take caoutchouc, melt it by a gentle heat, treat with 6 to 8 per cent, by weight of tallow, taking care to keep the mass well stirred ; add dry slaked lime, so as to give DURABLE CEMENTS AND PAINTS. 529 the fluid mass the consistency of soft paste ; and, lastly, stir in 20 per cent, of red lead, whereby the mass which would otherwise remain soft becomes hard and dry. This cement resists, according to Dr. Wagner, boiling sulphuric acid. A solution of caoutchouc, in twice its weight of raw linseed-oil, aided by heating, and the addition thereto of an equal weight of pipe-clay, yields a plastic mass, which also • resists most acids. Cements for Steam-Pipes . A very excellent cement, which is imper¬ meable by air or steam, and very suitable, therefore, for making tight the joints of steam-pipes, is made by kneading together into a perfect mixture the following ingre¬ dients :— Graphite, finely powdered - 3 lbs. Lime, slackened and sifted - ~ 3 „ Sulphate of lime, in fine powder - 8 „ Boiled linseed oil - - 7 „ Artificial Stone. A very excellent stone or cement may be made by melting together 200 pounds of M M 530 PURE FERTILIZERS . l stearic pitch, 20 pounds of sulphur, and barely enough of spirits of turpentine to give it a thin pasty fluidity. At this stage, 50 pounds of finely-powdered lime, 200 pounds of ground plaster, and 25 cubic feet of very fine sand are to be added by degrees, and well stirred into the mixture, after which the mass is to be melted and pressed into bricks. This stone hardens in five to eight days. INDEX. Acid reservoir, the, 113 Alabaster, 83 Alkaline salts, estimation of, in mineral phosphates, 457 Alma, M. de, 416 Alta Vela guano, 50, 161, 223, 237, 246, 360-363, 395, 399, 400, 402, 403, 406, 407, 409 ; analysis of, 364 ; treat¬ ment of for manure, 365 ; replaced by Morfit’s “mother- liquor”, 398 ; valuation of, 506, 507, 508 Alum, from phosphate of alumina, 408 Alumina, estimation of in mineral phosphates, 455 -phosphate of, not without fertilizing effect, 3 ; estimation of in mineral phosphates, 89, 408, 414, 455 ; commercial valuation of, 506, 508 -phosphate, left in mother-liquor when phosphate of lime is precipitated, 378 ; useful for defecation of sewage, 161,402,414; in manufacture of sugar, 415; in dyeing, 417 ; as glaze for pottery, 418 -phosphate of, Peter Spence’s patent for treatment of mineral, 379; also J. Berger Spence and Peter Dunn’s, 383, 385 ; also Townsend’s, 389 ■-and iron, formula for the chemical analysis of mineral phosphates of, 465 Aluminate of soda, a ready saponifier, 409 Aluminium, oxide of, 88 M M 2 532 INDEX . Ammonia, sources of, 44 ; wool, 44; leather clippings, 45 ; dried blood and flesh, 46 ; excreta, 47; sewage, 49, 399, 406 ; atmospheric air, 488 Ammonia, its defects as a precipitant of phosphate of lime, 163 -crude liquor of, production and constitution of, 39; estimates of evolution from coal, 40; separation from gas-liquor, 41-44 ; as an economiser, 284 -generator, the, 176 -hydrochlorate of, 57 -phosphate of, 41 ■-sulphate of, constitution and manufacture, 55, 57 ; use as an economiser, 280, 284 -commercial valuation of, 486, 487, 488, 489 Ammoniacal wash, 197 Ammonium, chloride of, 7, 57; produced from sulphate of ammonia, 280 Animal charcoal, 7 Analysis, “ commercial ”, meretricious character of, 465,496, 497 Analyses of— Apatite, by Hunt, 30 ; by Voelcker, 30 German phosphorite, by Fresenius, 13 Russian phosphorite, by Grewingk, 14 Wicken coprolites, by Morfit, 17 Pas de Calais coprolites, by Morfit and Gerland, 17 Phosphorite, 30 Suffolk and Cambridge coprolites, 30 Sombrero guano, by Voelcker, 19 Ditto, by Evans and Jones, 19 Ditto, by Morfit, 30 St. Martin’s phosphate, by Voelcker, 20 South Carolina phosphate, by Morfit and Gerland, 22,30 Ditto, by Voelcker, 23 INDEX. 533 Analyses of— French phosphorite, by Voelcker, 25 Navasa guano or Cooperite, by Morfit and Gerland, 27, 30 Bone-ash, by Morfit, 30 Bone-black, by Morfit, 30 Guaymas guano, by Morfit, 30 Marlstones, by Morfit, 30 Orchila guano, by Morfit, 30 Rossa guano, by Morfit, 30 Table of comparative composition of crude natural phosphates, 30, 31 Wool, by Scherer, 44 Brighton chalk, by Schweitzer, 64 Tri-, di-, and bi-phosphates of lime, 68 “ Superphosphate”, commercial, 289, 292, 293, 325 ; pure, 300, 301, 323 Gerland’s sulphite of tri-phosphate of lime, 341, 342,359 Redonda guano, by Johnson, 364 Alta Vela guano, by Voelcker, 364 A. B. R. guano, 364 Sewage-precipitate by sulphuric solution of Alta Vela guano, 400 ; by Morfit’s “ mother-water”, 400 Apatite, 2, 7, 290; characteristics and sources of, 9, 10; solubility of, 28 ; analysis of Canadian, 30 A. R. B., a rock phosphate, 361 ; analysis of, 364; treat¬ ment for manure, 365 Artificial stone, 530 Austrian phosphorite, 13 Bahia, nitrate of soda, 66 Baking-powder, Horsford’s, 327 ; directions for use, 334 Baltic, the, 8 534 INDEX . Barreswill on gas-liquor, 42 Baumes hydrometer, 512 Bavaria, 10, 11 Bi-phosphate of lime, 73, 75, 303-314, 502, 503, 504 Bituminous cement, 524 Black Sea, the, 8 Blair, Harrison, 123 Blake’s crusher, 96, 97 ; table of sizes of, 100 Blood, dried, a source of ammonia, 46 “ Blow-up, the”, 229, 234, 241, 242, 244 Bohemia, 10 Boiler, steam, the, 109 Bone-ash, the typical phosphate of lime, 2, 67 ; its sources, 8 ; value as a fertilizer, 9; its solubility, 28; analysis of by Morfit, 31 ; the best material for “superphos¬ phate”, 200 ; but too good for the purpose, 291 ; method of analysis, 434; commercial valuation of, 489 Bone-black, made by calcining bones, 7; value as a ferti¬ lizer, 9 ; analysis of by Morfit, 31 ; ammonia incident to its production, 44 ; its solubility in soil, 69 ; com¬ mercial valuation of, 490 Bottger’s cement, 523 Bone-dust, commercial valuation of, 490 Bread, brown, 336 ; gout and confectioners’ cakes, 337 Brighton chalk, 64 Bristles, ammonia in, 44 Calcium, chloride of, constitution and properties of, 81,85; reaction with sulphate of potassa, 86 ; how utilized, 155, 277, 286 •- fluoride of, 84; estimation of in mineral phos¬ phates, 458 -oxide of, 61 INDEX . 535 Calcium, phosphate, sulphite of, 78 Cambridgeshire coprolites, 15 Canadian apatite, 9, 10; coprolites, 15 Carolina, South, phosphates, 20; analysis of by Morfit and Gerland, 22, and by Voelcker, 23 ; 170, 202, 204, 206, 208, 325 Carr, Thomas, his disintegrator, 133, 244, 376 Celsius’s or centigrade thermometer, 518 Cement for steam-pipes, 529 Cements, water and acid proof, 520, 523, 528, 529, 530 Cereal crops, fertilizer for, 426 Chalk, 64 Charcoal, animal, 7 ; peat, for sewage, 396 Chemical analysis of phosphatic materials and products, formulae for, 432 Chemistry, “commercial ”, style of analytical, 465, 496, 497 Chilian nitre, 66 Chloro-phosphate of lime, Way’s, 263 Church, A. H., 2, 12 Clark’s enamel, 232 Clegg, on ammonia in gas-liquor, 40 Cliff, 127 Collas, M., uses phosphate of alumina for dyeing, 417 Colombian guano or phosphate, 71, 72, 75, 78, 130, 160, 162, 216, 278, 301, 307 ; manufacture of, 203 ; first process, 204 ; the mother-liquor or wash, 221 ; second process, 222 ; formation of, 241, 298 Confectioners’ cakes, 337 Cooperite or Navasa guano, 25, 237 : analysis of, 31 Coprolites, 2; their nature and sources, 15, 16; Wicken and Pas de Calais, analysis by Morfit and Gerland, 17 ; value of, 494 Deligny, 227; his process for di-phosphate of lime, 259-263 536 INDEX. Digester, the, or solution vat, 117 Digestion, first fractional, 165 ; second ditto, 169 Di-phosphate of lime, 70, 72, 226, 227, 238, 501 Disinfectant, sulphite of tri-phosphate of lime as a, 353 Disintegrator, Carr’s, 133, 244, 300, 316, 323 Dominique, his report on phosphate of alumina in the puri¬ fication of sugar, 416 Dreschfeld, Dr. J., experiments with Gerland’s sulphite of tri-phosphate of lime, 354 Drying-kiln, the, 129 Dunger, universal, 426 Dunn, Peter, 41 ; patent for treatment of mineral phos¬ phate of alumina, 383, 385, 408 Dyeing, use of phosphate of alumina in, 417 Dyer, W. J. T., 2, 12 Elevator, the, 111 Engine, the steam, 109 Estremadura phosphorite, 11 Etchelss, W. G., on supply and market values of woollen waste, 45 Evans and Jones, analysis of Sombrero guano, 19 Evaporating-pan, the, 131 Excreta, human, a source of ammonia, 47 Fahrenheit’s thermometer, 517-519 Factory plant, arrangement of, 147 Feathers, ammonia in, 44 Feltz, E., on sugar fertilizers, 428 Fertilizers, normal, 425 ; universal dunger, 426 ; for cereal crops, 426; for leguminous plants, 427 ; for gramine¬ ous plants, 427 ; for sugar, 428 ; for root crops, 430 -compound, formula for analysis of, 469 INDEX. 537 Fertilizing materials, commercial valuation of, 485 Filter vats, 171 Flesh, dried, a source of ammonia, 46 Fluoride of calcium or fluor spar, constitution of, and pre¬ sence in rock guanos, 15, 84; estimation of in mineral phosphates, 458 Forbes’s defecation of sewage by phosphates of alumina and iron, 395 ; should be supplemented by filtration through peat charcoal, 396 Formulae for chemical analyses, 432 ; of phosphates of alumina and iron, 465 ; commercial “superphosphate”, 469; compound fertilizers, 470 French coprolites, 15 : phosphates, 24 Fremy on cements, 521 Fresenius, 13 ; analysis of German phosphates, 30 Furnace, the roasting, 109 Gas-liquor, as a source of ammonia, 40; its extensive pro¬ duction, 43 Generator, the ammonia, 176 Geological distribution of the mineral phosphates, 2 Gerland, Dr. B. W., analyses of Pas de Calais coprolites, 17 ; of South Carolina phosphates, 22 ; of Cooperite or Navasa guano, 27 ; his sulphite of tri-phosphate of lime, 338; method of manufacture, 346; its properties, 353'; and analysis, 356 German phosphates, 11; coprolites, 15 Gibbsite or Alta Vela guano, 361 Glue, marine, 527, 528 Gill, Haughton, on sugar, 430 “Going-back” of commercial “superphosphate”, 293, 308, 310, 505 Gossage’s coke-towers, 36 1 538 INDEX. Gout bread, 337 Gramineous plants, fertilizer for, 427 Grewingk’s analysis of Russian phosphorite, 14 Grinding apparatus, 92; roller mill, 93; sifter, 95 ; Blake’s crusher, 97 ; Howel- Hannay mill, 102 Guaymas guano, 17, 71 Gypsum, 83 Hayti, 25 Henry, Michael, 260 Herepath, analysis of Suffolk coprolites, 31 Horn, ammonia in, 44 Horsford’s baking-powder, 327 Hosch and Enderisch’s universal dunger, 426 Howel-Hannay mill, 97, 102, 323 Hunt, T. S., on apatite, 10; analysis of Canadian apatite, 30 Hydraulic cement, 520 Hydrochloric acid, its constitution and production, 36; Ure’s table of specific gravities, 38; preferred to sul¬ phuric acid for solution of phosphates, 156 Hydrometers, mode of using, 511 Inertia, fertilizing, of certain mineral phosphates, 3 Iron, oxide of, in mineral phosphates, 87, 453 -phosphate of, not without value as manure, 3 ; espe¬ cially when freshly precipitated, 88 ; estimation of in mineral phosphates, 87, 451 ; left in mother-liquor when phosphate of lime has been precipitated, 378 ; conjoined with phosphate of alumina for sewage pre¬ cipitation, 402 -phosphate of, commercial valuation of, 509 Johnson, analysis of Redonda guano, 364 INDEX. 539 Kamrodt, on sources of ammonia, 44 Kiln, the drying - , 129 Knapp, on gas-liquor, 42 La Plata, 8 Leather clippings a source of ammonia, 45 Leguminous plants, fertilizer for, 427 Lerverd, A., et Cie., 127 Liebig-Horsford baking-powder, 327 Lift, the, 112 Limburg and Stafifel phosphorite, 12 Lime, constitution and diffusion of, 61 - carbonate of, its constitution and diffusion, 63, 288 ; disadvantages of in association with phosphate of lime, 79-82 ; estimation of in mineral phosphates, 461 - chloro-phosphate of, 226 ; Way’s process for produc¬ tion of, 263-276 - Colombian phosphate of, 78, 203, 221, 241, 298, 500 - Gerland’s sulphite of tri-phosphate of, 338 ; method of manufacture, 346; its properties, 353; analysis, 356 - mineral phosphates of, method of analyses, 434; valuation of, 491. Table of their value per cent., 498 - organate of, 82 - phosphate of, its three chemical phases, 67 ; tri- or bone-phosphate, 68 ; its solubility in the soil, 69; various characteristics, 70 ; pure rare in Nature, 290 ; errors or tricks in estimation of, 326, 432. Commer¬ cial valuation of, 493-497 - bi-phosphate of, 73 ; favoured by agriculturists, but inferior to precipitated phosphate, 75 ; production of pure and wholly soluble, 303-314. Commercial valua- tion of, 502, 503, 504 1 540 INDEX. Lime, di- or neutral-phosphate of, 70-72 ; manufacture of, 226; ought to have first place among fertilizers, 227 ; Morfit’s process (A), 227 ; and process (B), 238. Commercial valuation of, 501 - precipitated phosphate of, its solubility in the soil, 75 : its production and characteristics, 76-78 : pulpy condition, 157 ; only less potent than Colombian guano, 162 ; eminently suited for conversion into “superphosphate”, 163; but almost too good for the purpose, 302. Valuation of, 499 - precipitated phosphate of, process of manufacture, 164 ; the purge or first fractional digestion, 165 ; the solution or second fractional digestion, 169 ; the pre¬ cipitation and the vacuum filter vats, 171 ; the am¬ monia generator, 176; the ammoniacal wash or mother-liquor, 197 ; the purge-liquor, 199 - sulphite of, 340 - “superphosphate” of, principle of production of, 288; manufacture of commercial, 315-326; delusive analy¬ ses of, 325 - sulphate of, 65 ; constitution and presence in rock guanos, 83 Magnesia, phosphate of, 79; estimation of in mineral phos¬ phates, 454; commercial valuation of, 505 Maracaibo, Colombian guano from, 71 Marl-stones, 2, 7, 20, 30 Marine glue, 527, 528 Marschall, on sugar fertilizers, 429 Martin’s, St., phosphate, 20 Mediterranean, the, 8 Mill, the roller, 93 INDEX. 54 i Mineral phosphates of lime, commercial valuation of, 491, 49 2 -alumina, 3 ; standard for valuation of, 494-495 -commercial valuation of, 508 Mixer, the, 115 ; mixing machines, 132 Monte-jus, the, 125, 169, 372 Morfit’s “ mother-liquor” as substitute for Alta Vela and Redonda guanos, 398 ; comparative composition of several precipitates, 400 - table of the value of crude phosphates of lime, 498 - table of the value of crude phosphates of alumina, 508 Morris and Penny’s ammonia process, 50-55 Mother-liquor or wash and mode of reclaiming its mate¬ rials, 197, 221, 277-287 ; its merits in sewage defeca¬ tion, 223, 235, 243, 378, 398, 402-418 Nassau phosphorite, 13 Navasa guano or Cooperite, 25 ; analysis of by Morfit and Gerland, 27 ; by Morfit, 31, 237 New Jersey, 10 New York, 10 Nitrate of soda, 66 Norway, 9, 10 Ogston, analysis of Spanish phosphate, 30 Oil of vitriol, 32, 321 Orchila guano, 27 ; analysis of by Morfit, 31 Organate of lime, 82 Organic matter in phosphates, 90 542 INDEX. Pan, the evaporating, 131 Paints, water and acid proof, 526 Passive condition of certain mineral phosphates, 3 Pearl-ash, 60 Peat-charcoal, in the defecation of sewage, 396 Penny and Morris’s ammonia process, 50-55 Peru, nitrate of soda from, 66 Phosphate of ammonia, 41 Phosphates, mineral, their wide diffusion in nature, 1 ; their constitution, 2 ; comparative solubility of, 28 ; must be finely powdered, 4; South Carolina, 20; analyses by Morfit and Gerland, 22, and Voelcker, 23 ; St. Martin’s analysis by Voelcker, 20 ; French, 24 ; ana¬ lysed by Voelcker, 25 ; organic matter in, 90 ; sand and silica, 91, 442; water, 91; South Carolina, 164, 166, 170, 202, 204, 208, 494 ; Colombian, 203 Phosphates, super, manufacture of, 288, 298-302, 315-326; delusive analyses of, 325 -of alumina. See Alumina -of lime, analytical tables of, 30, 31. See Lime -of magnesia. See Magnesia -of iron. See Iron -of soda. See Soda Phosphorite, 2, 7 ; characteristics and sources of supply, 11 ; Welsh, 11 ; German, 12; analysis, 13; Russian and Austrian, 13 ; Spanish, 290; analysis of Russian, 14 ; and of Spanish, 30 Phosphoric acid in sewage, 399 ; estimation of in mineral phosphates, 450 Phosphorus, 226 Pile, 514 Pitch, stearic, 113, 231 Plant, the, for manufacture of fertilizers, 108-146; arrange¬ ment of, 147-152; steam-boiler and engine, 109; INDEX. 543 roasting-furnace, 109; platform and accessories, no; elevator, hi; lift, 112; acid reservoir, 113 ; mixer, 115 ; digester or solution vat, 117 ; syphon, 123 ; the monte-jus, 125 ; precipitation vat, 127 ; drying-kiln, 129; wash-vat, 130; evaporating-pan, 131 ; mixing- machines, 132; Carr’s disintegrators, 133-146 ; Poole and Hunt’s mixer, 145 Plaster of Paris, 83 Platform, the, and its accessories, no Pockston on ammonia, 40 Poole and Hunt, Baltimore, their mixer, 145 Portland cement, 521 Potassa, carbonate of, 60 - sulphate of, 58, 282, 283, 284 Potassium, chloride of, 59 Potential, the application of the term in this treatise, 486, 499 Pottery, phosphate of alumina as a glaze for, 418 Precipitation, the, 171 Process, Morfit’s (A), 227 ; and (B), 238 Profligate constituents of mineral phosphates, 493 Purge, the, or first fractional digestion, 165 -liquor, the, 199 Ransome’s artificial stone, 155, 221, 278 Rcdoncla guano, 50, 237, 246, 287, 360, 361, 362, 371, 374, 376, 379. 383, 385. 390, 395, 399, 400, 408 ; analysis of, 364, 466 ; treatment for manure, 365 ; P. Spence’s treatment of, 379; also J. B. Spence and Dunn’s, 383; Townsend’s, 389 ; replaced by Morfit’s “ mother- liquor”, 398; commercial valuation of, 508 Reservoir, the acid, 113 544 INDEX . Reynoso introduces phosphate of alumina to sugar¬ refining - , 416 Roasting-furnace, the, 109 Rock guanos erroneously classified, 360 Roller-mill, the, 93 Reaumur’s thermometer, 519 Root crops, fertilizers for, 430 Rossa or Guaymas guano, 17, 30, 71 Russian phosphorite, 13 Sal ammoniac, 57 Salt, table, 409, 410 Salt of tartar, 60 Salts, alkaline, estimation of in mineral phosphates, 457 Saponifier, a ready, in aluminate of soda, 409; method of use, 413 Saxony, 10 Scherer, on ammonia in wool, 44 Schwachofter, on Russian phosphorite, 14 Selinite, 83 Sewage, the natural means of fertilization, 1 ; a source of ammonia, 47, 406 ; suggested method of treatment, 47-49 ; phosphate of alumina for defecation of, 161 ; Morfit’s “ mother-water” an admirable precipitant of, 223, 237, 402-418; its utilization a paramount problem of hygiene and economics, 1, 393 ; analysis of pre¬ cipitates by Morfit, 400 -of the Thames, 393 Shoddy a source of ammonia, 53 Siebenthal, B. de, 164 Sifter, the, 95 Silver, nitrate of, 220 INDEX. h a r Soda, aluminate of, 409 - nitrate of, 66 - phosphate of, 48 ; as an economiser, 287 Soda-lime, 51, 52 Soil, elements of fertility in, 420 ; variety of fertilizers, 422 Sombrero guano, 18; value first recognised by Morfit, 18 ; analyses by Voelcker, 18, Evans and Jones, 19, and Morfit, 31 SorePs cement, 523 Spanish phosphorite, 290 Spence, John Berger, 41 ; his patent for treatment of phosphate of alumina, 383, 385, 408 -Peter, his process for producing alum from phos¬ phate of alumina, 379, 408 Stassfurt, 59 Steam-boiler and engine, 109 Stearic pitch, 113, 231, 523 Suffolk coprolites, 15 Sugar, phosphate of alumina, use in manufacture of, 415 ; fertilizers for, 428 Sugar-ca?ie , the, cited, 416 Sulphite of calcium phosphate, 78 Stone, artificial, 530 Sulphite of tri-phosphate of lime, Gerland’s, 338 ; method of manufacture, 346; its properties, 353; analysis, 356 Sulphuric acid, its slovenly use in treating mineral phos¬ phates, 4; constitution and manufacture of, 32; tables of specific gravity, 34, 35 Superphosphate of lime, manufacture of, 288, 298, 315, 326; formula for analysis of, 469 Sweden, 9 Switzerland, 10 Syphon, the, 123 N N 546 INDEX. Thames sewage, 393 Thermometers, mode of using, 515 Townsend, Joseph, his conversion of Redonda guano into phosphate of soda, 287 ; his patent for treatment of phosphate of alumina, 389, 408 Turbines, 310 Twaddle’s hydrometer, 515 Universal dunger, 426 Ure, sulphuric acid table, 35 ; hydrochloric acid table, 38 Vacuum filters, the, 171 Valuation of crude and refined fertilizing materials, 485 Vat, cast-iron, 232 Vat, the solution, 117 ; the precipitation, 127; the wash, 130 Vats, the filter, 171 Venezuela, 27 Vitriol, oil of, 32, 321 Voelcker, Dr. Augustus, on apatite, 10; analysis of Ger¬ man phosphorite, 13 ; of Sombrero guano, 18 ; of St. Martin’s phosphate, 20; of South Carolina phosphate, 23 ; of French phosphate, 25 ; of Alta Vela guano, 364; on soils and drainage, 431 Wagner, 529 Wanklyn, analysis of Way’s di-phosphate of lime, 247 Warrington on action of carbonate of lime, 80 ; on coagu¬ lation of alumina salts by hot water, 471 Wash-vat, the, 130 INDEX. 547 Way, J. T., analysis of Cambridge coprolites, 31 ; his pro¬ cess for di-phosphate of lime, 227, 247-259 ; and for chloro-phosphate of lime, 263-276 Welsh phosphorite, 11 Whiting, 64 Wicken coprolites, 16, 17, 494 Williams, Charles P., on solubility of crude phosphates of lime, 28 Williman’s Island, 22 Wool, as a source of ammonia, 44 Woollen waste, 45 Wright, on ammonia, 40 THE END. T. RICHARDS, 37, GREAT QUEEN STREET, LONDON. UNIVERSfTY OF ILLINOIS-URBANA 3 0112 070675266