PRINCIPLES AND PRACTICE OF AGRICULTURAL ANALYSIS.

A MANUAL FOR THE EXAMINATION OF SOILS, FERTILIZERS, AND AGRICULTURAL PRODUCTS.

FOR THE USE OF ANALYSTS, TEACHERS, AND STUDENTS OF AGRICULTURAL CHEMISTRY.

VOLUME III.

AGRICULTURAL PRODUCTS.

BY HARVEY W. WILEY,

Chemist of the U. S. Department of Agriculture..

EASTON, PA. Chemical Publishing Co. 1897.

COPYRIGHT, 1897, By Harvey W. Wiley.

PREFACE TO VOLUME THIRD.

The concluding volume of the Principles and Practice of Agricultural Analysis has been written in harmony with the plan adopted at the commencement of the first volume. In it an effort has been made to place the analyst or student en rapport with all the best methods of studying the composition of agricultural products. During the progress of the work the author has frequently been asked why some special method in each case has not been designated as the proper one to be used. To do this would be a radical departure from the fundamental idea of the work; viz., to rely on the good judgment and experience of the chemist. It is not likely that the author’s judgment in such matters is better than that of the analyst using the book, and, except for beginning students pursuing a course of laboratory instruction, a biased judgment is little better than none at all. For student’s work in the laboratory or classroom it is probable that a volume of selected methods based on the present work may be prepared later on, but this possible future need has not been allowed to change the purpose of the author as expressed in the preface of the second volume “to present to the busy worker a broad view of a great subject.” For the courtesy and patience of the publishers, for the uniformly commendatory notices of the reviewers of volumes one and two, and for the personal encouraging expressions of his professional brethren the author is sincerely grateful. He finds in this cordial reception of his book a grateful compensation for long years of labor. The plates of the first edition of the three volumes have been destroyed in order to insure a re-writing of the second edition when it shall be demanded, in order to keep it abreast of the rapid progress in the field of agricultural chemical analysis.

Washington, D. C., Beginning of January, 1897.

TABLE OF CONTENTS OF VOLUME THIRD.

PART FIRST.

SAMPLING, DRYING, INCINERATION AND EXTRACTIONS.

Introduction, pp. 1-3.—Methods of study; Scope of the work; Limitations of work; General manipulations.

Methods of Sampling, pp. 3-13.—Vegetable substances; Animal substances; Preserving samples; Collecting samples; Grinding samples; Grinding apparatus.

Drying Organic Bodies, pp. 13-36.—Volatile bodies; Drying ovens; Air baths; Drying in vacuum; Electric drying ovens; Steam coil apparatus; Drying in hydrogen; Drying in tubes; Drying viscous liquids; General principles of drying.

Incineration, pp. 36-40.—Principles of incineration; Products of combustion; Purpose and conduct of incineration; German ash method; Courtonne’s muffle.

Extraction of Organic Bodies, pp. 40-57.—Object of extraction; Solvents; Methods of extraction; Extraction by digestion; Extraction by percolation; Apparatus for extraction; Knorr’s extraction apparatus; Soxhlet’s extraction apparatus; Compact extraction apparatus; Recovery of solvents; Authorities cited in Part First.

PART SECOND.

SUGARS AND STARCHES.

Introduction, pp. 58-62.—Carbohydrates; Nomenclature; Preparation of pure sugar; Classification of methods of analysis.

Analysis by Density of Solution, pp. 63-72.—Principles of the method; Pyknometers; Calculating volume of pyknometers; Hydrostatic balance; Areometric method; Correction for temperature; Brix hydrometer; Comparison of brix and baumé degrees; Errors due to impurities.

Estimation of Sugars with Polarized Light, pp. 74-120.—Optical properties of sugars; Polarized light; Nicol prism; Polariscope; Kinds of polariscopes; Character of light; Description of polarizing instruments: Laurent polariscope; Polariscope lamps; Soleil-Ventzke polariscope; Half Shadow polariscope; Triple field polariscope; Setting the polariscope; Control observation tube; Quartz plates; Correcting quartz plates; Application of quartz plates; Sugar flasks; Preparing sugar solutions for polarization; Alumina cream; Errors due to lead solutions; Double polarization; Mercuric compounds; Bone-black; Inversion of sugar; Clerget’s method; Influence of strength of solution; Calculation of results; Method of Lindet; Use of invertase; Activity of invertase; Inversion by yeast; Determination of sucrose; Determination of raffinose; Specific rotatory power; Calculating specific rotatory power; Variations in specific rotatory power; Gyrodynatic data; Birotation.

Chemical Methods of Estimating Sugar, pp. 120-149.—General principles; Classification of methods; Reduction of mercuric salts; Sachsse’s solution; Volumetric copper methods; Action of copper solution on dextrose; Fehling’s solution; List of copper solutions; Volumetric laboratory method; Filtering tubes; Correction of errors; Permanganate process; Modified permanganate method; Specific gravity of cuprous oxid; Soldaini’s process; Relation of reducing sugar to quantity of suboxid; Factors for different sugars; Pavy’s process; Peska’s process; Method of Allein and Gaud; Method of Gerrard; Sidersky’s modification; Titration of excess of copper.

Gravimetric Copper Methods, pp. 149-170.—General principles; Laboratory copper method; Halle method; Allihn’s method; Meissl’s method; Determination of invert sugar; Estimation of milk sugar; Determination of maltose; Preparation of levulose; Estimation of levulose.

Miscellaneous Methods of Sugar Analysis, pp. 171-196; Phenylhydrazin; Molecular weights of carbohydrates; Birotation; Estimation of pentosans; Determination of furfurol; Method of Tollens; Method of Stone; Method of Chalmot; Method of Krug; Precipitation with pyrogalol; Precipitation with phloroglucin; Fermentation methods; Estimating alcohol; Estimating carbon dioxid; Precipitation with earthy bases; Barium saccharate; Strontium saccharate; Calcium saccharate; Qualitive tests; Optical tests; Cobaltous nitrate test; The Dextrose group; Tests for levulose; Tests for galactose; Tests for invert sugar; Compounds with phenylhydrazin; Detection of sugars by means of furfurol; Bacterial action on sugars.

Determination of Starch, pp. 196-226.—Constitution of starch; Separation of starch; Methods of separation; Separation with diastase; Separation in an autoclave; Principles of analysis; Estimation of water; Estimation of ash; Estimation of nitrogen; Hydrolysis with acids; Factors for calculation; Polarization of starch; Solution at high pressure; Method of Hibbard; Precipitation with barium hydroxid; Disturbing bodies in starch determinations; Colorimetric estimation of starch; Fixation of iodin; Identification of starches; Vogel’s table; Muter’s table; Blyth’s classification; Preparation of starches for the microscope; Mounting in canada balsam; Description of typical starches; Authorities cited in Part Second.

PART THIRD.

SEPARATION AND DETERMINATION OF CARBOHYDRATES IN CRUDE OR MANUFACTURED AGRICULTURAL PRODUCTS.

Sugars in Vegetable Juices, pp. 227-253.—Introduction; Sugar in the sap of trees; Sugar in sugar canes; Weighing pipettes; Gravimeter; Reducing sugars in juices; Preservation of juices; Direct estimation of sugar; Cutting or shredding canes; Methods of analysis; Drying and extracting; Examination of bagasse; Fiber in canes; Sugar beets; Estimation of sugar in sugar beets; Machines for pulping beets; Instantaneous diffusion; Pellet’s process; Alcohol digestion; Extraction with alcohol; Determination of sugar in mother beets; Determination of sugars without weighing; Continuous observation tube.

Analysis of Sirups and Massecuites, pp. 254-264.—Specific gravity; Determination of water; Determination of ash; Determination of reducing sugars; Estimation of minute quantities of invert sugar; Soldaini’s gravimetric method; Weighing the copper as oxid; Analyses for factory control.

Separation of Carbohydrates in Mixtures, pp. 264-292.—Occurrence of sugars; Optical methods; Optical neutrality of invert sugar; Separation of sucrose and invert sugar; Separation of sucrose and raffinose; Determination of levulose; Formula for calculating levulose; Separation of sucrose from dextrose; Estimation of lactose in milk; Error due to volume of precipitate; Separation of sucrose, levulose and dextrose; Sieben’s method; Wiechmann’s method; Copper carbonate method; Winter’s process; Separation with lead oxid; Analysis of commercial glucose and grape sugar; Fermentation method; Oxidation method; Removal of dextrose by copper acetate; Separation of dextrin with alcohol.

Carbohydrates in Milk, pp. 293-298.—Copper tartrate method; The official method; The copper cyanid process; Separation of sugars in evaporated milks; Method of Bigelow and McElroy.

Separation and Determination of Starch and Fiber, pp. 298-306.—Occurrence; Separation of starch; Dry amyliferous bodies; Indirect method of determining water; Removal of oils and sugars; Preparation of diastase; Estimation of starch in potatoes; Constitution of cellulose; Fiber in cellulose; Official method; Separation of cellulose: Solubility of cellulose; Qualitive reactions for cellulose; Rare carbohydrates; Authorities cited in Part Third.

PART FOURTH.

FATS AND OILS.

General Principles, pp. 309-316.—Nomenclature; Composition; Principal glycerids; Presses for extraction; Solvents; Freeing extracts of petroleum; Freeing fats of moisture; Sampling and drying for analysis; Estimation of water.

Physical Properties of Fats and Oils, pp. 317-350.—Specific gravity; Balance for determining specific gravity; Expression of specific gravity; Coefficient of expansion of oils; Densities of common fats and oils; Melting point; Determination in capillary tube; Determination by spheroidal state; Solidifying point; Temperature of crystallization; Refractive power; Refractive index; Abbe’s refractometer; Pulfrich’s refractometer; Refractive indices of common oils; Oleorefractometer; Butyrorefractometer; Range of application of the butyrorefractometer; Viscosity; Torsion viscosimeter; Microscopic appearance; Preparation of fat crystals; Observation of fat crystals with polarized light; Spectroscopic examination of oils; Critical temperature; Polarization; Turbidity temperature.

Chemical Properties of Fats and Oils, pp. 351-406.—Solubility in alcohol; Coloration produced by oxidants; Nitric acid coloration; Phosphomolybdic acid coloration; Picric acid coloration; Silver nitrate coloration; Stannic bromid coloration; Auric chlorid coloration; Thermal reactions; Heat of sulfuric saponification; Maumené’s process; Method of Richmond; Relative maumené figure; Heat of bromination; Method of Hehner and Mitchell; Author’s method; Haloid addition numbers; Hübl number; Character of chemical reaction; Solution in carbon tetrachlorid; Estimation of the iodin number; Use of iodin monochlorid; Preservation of the hübl reagent; Bromin addition number; Method of Hehner; Halogen absorption by fat acids; Saponification; Saponification in an open dish; Saponification under pressure; Saponification in the cold; Saponification value; Saponification equivalent; Acetyl value; Determination of volatile fat acids; Removal of the alcohol; Determination of soluble and insoluble fat acids; Formulas for calculation; Determination of free fat acids; Identification of oils and fats; Nature of fat acids; Separation of glycerids; Separation with lime; Separation with lead salts; Separation of arachidic acid; Detection of peanut oil; Bechi’s test; Milliau’s test; Detection of sesamé oil; Sulfur chlorid reaction; Detection of cholesterin and phytosterin; Absorption of oxygen; Elaidin reactions; Authorities cited in Part Fourth.

PART FIFTH.

SEPARATION AND ESTIMATION OF BODIES CONTAINING NITROGEN.

Introduction and Definitions, pp. 410-418.—Nature of nitrogenous bodies; Classification of proteids; Albuminoids; Other forms of nitrogen; Occurrence of nitrates.

Qualitive Tests for Nitrogenous Bodies, pp. 418-422.—Nitric acid; Amid nitrogen; Ammoniacal nitrogen; Proteid nitrogen; Qualitive tests for albumni; Qualitive tests for peptones and albuminates; Action of polarized light on albumins; Alkaloidal nitrogen.

Estimation of Nitrogenous Bodies in Agricultural Products, pp. 423-432.—Total nitrogen; Ammoniacal nitrogen; Amid nitrogen; Sachsse’s method; Preparation of asparagin; Estimation of asparagin and glutamin; Cholin and betain; Lecithin; Factors for calculating results; Estimation of alkaloidal nitrogen.

Separation of Proteid Bodies in Vegetable Products, pp. 432-448.—Preliminary treatment; Character of proteids; Separation of gluten; Extraction with water; Action of water on composition of proteids; Extraction with dilute salt solution; Separation of bodies soluble in water; Separation of the globulins; Proteids soluble in dilute alcohol; Solvent action of acids and alkalies; Method of extraction; Methods of drying separated proteids; Determination of ash; Determination of carbon and hydrogen; Estimation of nitrogen; Determination of sulfur; Dialysis.

Separation and Estimation of Nitrogenous Bodies in Animal Products, pp. 448-462.—Preparation of sample; Extraction of muscular tissues; Composition of meat extracts; Analysis of meat extracts; Use of phosphotungstic acid; Separation of albumoses and peptones; Estimation of gelatin; Estimation of nitrogen in flesh bases; Treatment of residue insoluble in alcohol; Pancreas peptone; Albumose peptone; Authorities cited in Part Fifth.

PART SIXTH.

DAIRY PRODUCTS.

Milk, pp. 464-512.—Composition of milk; Alterability of milk; Effects of boiling on milk; Micro-organisms of milk; Sampling milk; Scovell’s milk sampler; Preserving milk for analysis; Freezing point; Electric conductivity; Viscosity; Acidity and alkalinity; Determination of acidity; Opacity; Creamometry; Specific gravity; Lactometry; Quévenne lactometer; Lactometer of the New York Board of Health; Density of sour milk; Density of milk serum; Total solids; Formulas for calculating total solids; Determination of ash; Estimation of fat; Fat globules; Number of fat globules; Counting globules; Classification of methods of analysis; Dry extraction methods; Official methods; Variations of extraction methods; Gypsum method; Estimation of fat in malted milk; Comparison of fat methods; Wet extraction methods; Solution in acid; Solution in alkali; Method of Short; Method of Thörner; Liebermann’s method; Densimetric methods; Areometric methods; Lactobutyrometer; Volumetric methods of fat analysis; Method of Patrick; The lactocrite; Modification of Lindström; Babcock’s method; Method of Leffmann and Beam; Method of Gerber; Proteid bodies in milk; Estimation of total proteid matter; Copper sulfate as a reagent; Precipitation by ammonium sulfate; Precipitation by tannic acid; Separation of casein from albumin; Estimation of casein; Factors for calculation; Separation of casein; Separation of casein with carbon dioxid; Separation of albumin; Separation of globulin; Precipitants of milk proteids; Precipitation by dialysis; Carbohydrates in milk; Dextrinoid body in milk; Amyloid bodies in milk.

Butter, pp. 512-523.—General principles of analysis; Appearance of melted butter; Microscopic examination; Refractive power; Estimation of water, fat, casein, ash and salt; Volatile and soluble acids; Relative proportion of glycerids; Saponification value; Reichert number; Reichert-Meissl method; Elimination of sulfurous acid; Errors due to poor glass; Molecular weight of butter; Substitutes for and adulterants of butter; Butter colors.

Cheese and Koumiss, pp. 524-536.—Composition of cheese; Manufacture of cheese; Official methods of analysis; Process of Mueller; Separation of fat from cheese; Filled cheese; Separation of nitrogenous bodies; Preparation of koumiss; Determination of carbon dioxid; Acidity; Estimation of alcohol; Proteids in koumiss; Separation by porous porcelain; Separation by precipitation with alum; Separation with mercury salts; Determination of water and ash; Composition of koumiss; Authorities cited in Part Sixth.

PART SEVENTH.

MISCELLANEOUS AGRICULTURAL PRODUCTS.

Cereals and Cereal Foods, pp. 541-545.— Classification; General methods of analysis; Composition and analysis of bread; Determination of alum in bread; Chemical changes produced by baking.

Fodders, Grasses, and Ensilage, pp. 545-547.—General principles of analysis; Organic acids in ensilage; Changes due to fermentation; Alcohol in ensilage; Comparative values of dry fodder and ensilage.

Flesh Products, pp. 547-555.—Names of meats; Sampling; General methods of analysis; Examination of nitrogenous bodies; Fractional analysis of meats; Starch in meats; Detection of horse flesh.

Methods of Digestion, pp. 555-564.—Artificial digestion; Amylolytic ferments; Aliphalytic ferments; Proteolytic ferments; Pepsin and pancreatin; Digestion in pancreas extract; Artificial digestion of cheese; Natural digestion; Digestibility of pentosans.

Preserved Meats, pp. 565-566.—Methods of examination; Estimation of fat; Meat preservatives.

Determination of Nutritive Values, pp. 566-576.—Nutritive value of foods; Comparative value of food constituents; Nutritive ratio; Calorimetric analysis of foods; Combustion in oxygen; Bomb calorimeter; Manipulation and calculation; Computing the calories of combustion; Calorimetric equivalents; Distinction between butter and oleomargarin.

Fruits, Melons and Vegetables, pp. 577-582.— Preparation of samples; Separation of carbohydrates; Examination of the fresh matter; Examination of fruit and vegetable juices; Separation of pectin; Determination of free acid; Composition of fruits; Composition of ash of fruits; Dried fruits; Zinc in evaporated fruits; Composition of melons.

Tea and Coffee, pp. 582-588.—Special points in analysis; Estimation of caffein; Iodin method; Spencer’s method; Separation of chlorophyll; Determination of proteid nitrogen; Carbohydrates of coffee; Estimation of galactan; Revised factors for pentosans; Use of roentgen rays.

Tannins and Allied Bodies, pp. 588-596.— Occurrence and composition; Detection and estimation; Precipitation with metallic salts; The gelatin method; The hide powder method; Permanganate gelatin method; Permanganate hide powder method; Preparation of infusion.

Tobacco, pp. 596-610.—Fermented and unfermented tobacco; Acid and basic constituents; Composition of ash; Composition of tobacco; Estimation of water; Estimation of nitric acid; Estimation of sulfuric and hydrochloric acids; Estimation of oxalic, malic and citric acids; Estimation of acetic acid; Estimation of pectic acid; Estimation of tannic acid; Estimation of starch and sugar; Estimation of ammonia; Estimation of nicotin; Polarization method of Popovici; Estimation of amid nitrogen; Fractional extraction; Burning qualities; Artificial smoker.

Fermented Beverages, pp. 610-641.— Description; Important constituents; Specific gravity; Determination of alcohol; Distilling apparatus; Specific gravity of the distillate; Hydrostatic plummet; Calculating results; Table giving percentage of alcohol by weight and volume; Determination of percentage of alcohol by means of vapor temperature; Improved ebullioscope; Indirect determination of extract; Determination of total acids; Determination in a vacuum; Estimation of water; Total acidity; Volatile acids; Tartaric acid; Tartaric, malic and succinic acids; Polarizing bodies in fermented beverages; Reducing sugars; Polarization of wines and beers; Application of analytical methods; Estimation of carbohydrates; Determination of glycerol; Coloring matters; Determination of ash; Determination of potash; Sulfurous acid; Salicylic acid; Detection of gum and dextrin; Determination of nitrogen; Substitutes for hops; Bouquet of fermented and distilled liquors; Authorities cited in Part Seventh; Index.

ILLUSTRATIONS TO VOLUME THIRD.

Page.

Figure 1. Mill for grinding dry samples 7

” 2. Comminutor for green samples 9

” 3. Rasp for sugar beets 10

” 4. Dreef grinding apparatus 11

” 5. Water jacket drying oven 14

” 6. Thermostat for Steam-Bath 15

” 7. Spencer’s drying oven 17

” 8. Electric vacuum drying oven 19

” 9. Steam coil drying oven 21

” 10. Carr’s vacuum drying oven 22

” 10. (Bis.) vacuum oven open 23

” 11. Apparatus for drying in a current of hydrogen 25

” 12. Caldwell’s hydrogen drying apparatus 27

” 13. Liebig’s ente 28

” 14. Drying apparatus used at the Halle Station 29

” 15. Wrampelmayer’s oven 30

” 16. Ulsch drying oven 31

” 17. Courtoune muffle 39

” 18. Knorr’s extraction apparatus 45

” 19. Extraction flask 46

” 20. Extraction tube 46

” 21. Extraction siphon tube 46

” 22. Soxhlet extraction apparatus 48

” 23. Compact condensing apparatus 49

” 24. Improved compact extraction apparatus 51

” 25. Knorr’s apparatus for recovering solvents 54

” 26. Apparatus for recovering solvents from open dishes 55

” 27. Common forms of pyknometers 63

” 28. Bath for pyknometers 66

” 29. Aereometers, pyknometers and hydrostatic balance 68

” 30. Hydrostatic balance 69

” 31. Course of rays of light in a nicol 77

” 32. Theory of the nicol 78

” 33. Laurent lamp 83

” 34. Lamp for producing constant monochromatic flame 85

” 35. Field of vision of a Laurent polariscope 86

” 36. Laurent polariscope 88

” 37. Tint polariscope 89

” 38. Double compensating shadow polariscope 91

” 39. Triple shadow polariscope 92

” 40. Apparatus for producing a triple shadow 92

” 41. Control observation tube 95

” 42. Apparatus for the volumetric estimation

of reducing sugars 131

” 43. Apparatus for the electrolytic deposition of copper 151

” 44. Apparatus for filtering copper suboxid 154

” 45. Apparatus for reducing copper suboxid 154

” 46. Distilling apparatus for pentoses 179

” 47. Autoclave for starch analysis 199

” 47. (Bis). Maercker’s hydrolyzing apparatus for starch 204

” 48. Maranta starch × 350 to face 220

” 49. Potato starch × 350

” 50. Ginger starch × 350

” 51. Sago starch × 350

” 52. Pea starch × 350

” 53. Bean starch × 350

” 54. Wheat starch × 350

” 55. Barley starch × 350

” 56. Rye starch × 350

” 57. Oat starch × 350

” 58. Indian corn starch × 350

” 59. Rice starch × 350

” 60. Cassava starch × 150

” 61. Indian corn starch × 150

” 62. Laboratory cane mill 230

” 63. Weighing pipette 231

” 64. Gird’s gravimeter 233

” 65. Machine for cutting canes 236

” 66. Cane cutting mill 237

” 67. Apparatus for pulping beets 243

” 68. Apparatus for cold diffusion 245

” 69. Sickel-Soxhlet extractor 247

” 70. Scheibler’s extraction tube 248

” 71. Battery for alcoholic digestion 250

” 72. Rasp for sampling mother beets 251

” 73. Hand press for beet analysis 251

” 74. Perforating rasp 252

” 75. Tube for continuous observation 253

” 75. (Bis). Chandler and Rickett’s Polariscope 266

” 76. Apparatus for polarimetric observations

at low temperatures 267

” 77. Construction of desiccating tube 268

” 78. Apparatus for polarizing at high temperatures 269

” 79. Oil press 312

” 80. Apparatus for fractional distillation

of petroleum ether 314

” 81. Section showing construction of a funnel

for hot filtration 316

” 82. Balance and Westphal sinker 318

” 83. Melting point tubes 322

” 84. Apparatus for the determination of melting point 324

” 85. Apparatus for determining crystallizing point 327

” 86. Abbe’s refractometer 329

” 87. Charging position of refractometer 330

” 88. Prism of Pulfrich’s refractometer 331

” 89. Pulfrich’s new refractometer 332

” 90. Heating apparatus for Pulfrich’s refractometer 333

” 91. Spectrometer attachment 333

” 92. Oleorefractometer 335

” 93. Section showing construction of oleorefractometer 335

” 94. Butyrorefractometer 339

” 95. Doolittle’s viscosimeter 343

” 96. Lard crystals × 65 to face 348

” 97. Refined lard crystals × 65

” 98. Apparatus for determining rise of temperature

with sulfuric acid 358

” 99. Apparatus for determining heat of bromination 362

” 100. Olein tube 374

” 101. Apparatus for saponifying under pressure 380

” 102. Apparatus for the distillation of volatile acids 388

” 103. Apparatus for amid nitrogen 425

” 104. Sachsse’s eudiometer 425

” 105. Dialyzing apparatus 447

” 106. Scovell’s milk sampling tube 470

” 107. Lactoscope, lactometer, and creamometer 474

” 108. Areometric fat apparatus 493

” 109. Babcock’s butyrometer and acid measure 500

” 110. Gerber’s butyrometers 502

” 111. Gerber’s centrifugal 503

” 112. Thermometer for butyrorefractometer 515

” 113. Apparatus for determining carbon dioxid in koumiss 533

” 114. Cuts of mutton 548

” 115. Cuts of beef 548

” 116. Cuts of pork 548

” 117. Bath for artificial digestion 559

” 118. Bag for collecting feces 563

” 119. Fecal bag attachment 563

” 120. Hempel and Atwater’s calorimeter 570

” 121. Apparatus for acetic acid 603

” 122. Apparatus for smoking 610

” 123. Metal distilling apparatus 613

” 124. Distilling apparatus 614

” 125. Improved ebullioscope 623

VOLUME THIRD.

AGRICULTURAL PRODUCTS.