/ AS? Is, HOW CROPS GROW. A TREATISE ON THE COMPOSITION, STRUCTURE, AND LIFE OF Til'HE PLANT, FOR ALL STUDENTS F AGRICULTURE. ALL STUDENTS OF AGRICULTURE. WITH NUMEROUS ILLUSTRATIONS AND 1ABLES OF ANALYSES& BY SAMUEL W. JOHNSON, M. A., PROFESSOR OF ANALYTICAL AND AGRICULTURAL CHEMISTRY IN THE SI'VWT/D SCIE.NTIFIC SCHOOL OF YALE COLLEGE; CHEMIST TO THE CCEXO TICUT STATE AGRICULTURAL SOCIETY MEKBEY OF TRI NATIONAL ACADEMY OF SCIENCES. NEW YORK: ORANGE JUDD & COMPANY, 245 BROADWAY. I CHEMICAL I Entered according to Act of Congress, in the yeai 1868, by ORANGE JUDD & CO., At the Clerk's Office of the District Court of the Unit(,d States for the Southern District of New-York. II Lovwoy, SoN & Co., ELECTROTYPERS & STM-.OTYPR.S, 15 Yandewater Street, N. Y. I ol I PREFACE. For the last twelve years it has been the duty of the writer to pronounce a course of lectures annually upon Agricultural Chemistry and Physiology to a class in the Scientific School of Yale College. This volume is a result of studies undertaken in preparing these lectures. It is intended to be one of a series that shall cover the whole subject of the applications of Chemical and Physiological Science to Agricultur%, and is offered to the public in the hope that it will supply a deficiency that has long existed in English literature. The progress of these branches of science during recent years has been very great. Thanks to the activity of numerous English, French, and especially German inivestigators, Agricultural Chemistry has ceased to be the monopoly of speculative minds, and is well based on a foundation of hard work in the study of facts and first principles. Vegetable Physiology has likewise made re:arkable advances, has disencumbered itself of many iseless accumulations, and has achieved much that is of direct bearing on the art of cultivation. The author has endeavored in this work to lay out a groundwork of facts sufficiently complete to reflect a true and well-proportioned image of the nature and needs of the plant, and to serve the student of agriculture for thoroughly preparing himself to comprehend the whole 3 iI - o nOW CROPS GROW. subject of vegetable nutrition, and to estimate accurately how and to what extent the crop depends upon the atmosphere.on the one hand, and the soil on the other, for the elements of its growth. It has been sought to present the subject inductively, to collate and compare, as far as possible, all the facts, and so to describe and discuss the methods of investigation that the conclusions given shall not rest on any individual authority, but that the student may be able to judge himself of their validity and importance. In many cases fulness of detail has been employed, from a conviction that an acquaintance with the sources of information, and with the processes by which a problem is attacked and truth arrived at, is a necessary part of the education of those who are hereafter to be of service in the advancement of agriculture. The Agricultural Schools that are coming into operation should do more than instruct in the general results of Agricultural Science. They should teach the subject so thoroughly that the learner may comprehend at once the deficiencies and the possibilities of our knowledge. Thus we may hope that a company of capable investigators may be raised up, from whose efforts the science and the art may receive new and continual impulses. In preparing the ensuing pages the writer has kept his eye steadily fixed upon the practical aspects of the subject. A multitude of interesting details have been omitted for the sake of comprising within a reasonable space that information which may most immediately serve the agriculturist. It must not, however, be forgotten, that a valuable principle is often arrived at from the study of facts, which, considered singly, have no visible connection with a practical result. Statements are made which may appear far more curious than useful, and that have, at present, a simply speculative interest, no mode being apparent by which the farmer can increase his crops or diminish his labors by help TV I I PREFACE. of his acquaintance with them. Such facts are not, however, for this reason to be ignored or refused a place in our treatise, nor do they render our book less practical or less valuable. It is just such curious and seemingly useless facts that are often the seeds of vast advances in industry and arts. For those who have not enjoyed the advantages of the schools, the author has sought to unfold his subjects by such regular and simple steps, that any one may easily master them. It has also been attempted to adapt the work in form and contents to the wants of the class-room by a strictly systematic arrangement of topics, and by division of the matter into convenient paragraphs. To aid the student who has access to a chemical laboratory and desires to make himself practically familiar with the elements and compounds that exist in plants, a number of simple experiments are described somewhat in detail. The repetition of these will be found extremely useful by giving the learner an opportunity of sharpening his perceptive powers, as well as of deepening the impre.ssions of study. The author has endeavored to make this volume complete in itself, and for that purpose has introduced a short section on The Food of the Plant. In the succeeding volume, which is nearly ready for the printer, to be entitled "Hlow Crops Feed," this subject will be amplified in all its details, and the atmosphere and the soil will be fully discussed-in their manifold Relations to the Plant. A third volume, it is hoped, will be prepared at an early day upon Cultivation; or, the Improvement of the Soil and the Crop by Tillage and Manures. Lastly, if time and strength do not fail, a fourth work on Stock Feeding and Dairy Produce, considered from the point of view of chemical and physiological science, may finish the series. It is a source of deep and continual regret to the writer that his efforts in the field of agriculture have been mostly k v I N I HOW CROPS GROW. confined to editing and communicating the results of the labors of others. He will not call it a misfortune that other duties of life and of his professional position have fully employed his time and his energies, but the fact is his apology for beimg a middle man and not a producer of the priceless commodities of science. He hopes yet that circumstances may put it in his power to give his undivided attention to the experimental solution of numerous problems which now perplex both the philosopher and the farmer; and he would earnestly invite young men reared in familiarity with the occupations of the farm, who are conscious of the power of investigation, to enter the fields of Agricultural Science, now white with a harvest for which the reapers are all too few. I 'f I VI I I i ACKNOWLEDGMENTS. The author would express his thanks to his friend Dr. Peter Collier, Professor of Chemistry in the University of Vermont, for a large share of the calculations and re ductions required for the Tables pp. 150-6. Of the illustrations, fig's 3, 4, 5, 7, 47, 63, and 64, were drawn by Mr. Lockwood Sanford, the engraver. For oth ers, acknowledgments are due to the following authors, from whose works they have been borrowed, viz.: SCHLEIDEX.-Fig's 10, 13, 17, 19, 30, 48, 49, and 50, Physiologie der PJflanzen und Thiere. SACHS.-Fig's 56 and 65, Sitzungsberichte der Wiener Akademie, XXXVII, 1859, and fig's 22, 38, 40, 41, 42, 43, 59, 66, 69, 70, and 71, Experimental-Physiologie der Pfanzen. PAYEN.-Fig's 11, 12, and 23, Precis de Chimie Indues trielle. DUCHARTRE.-Fig's 60 and 61, Ple'ment8 de Botanique. KUHN. - Fig's 18, 21a, 29, and 34, ErnArung des . Rindviehes. IIARTIG.-Fig's 20, 21b, 32, Entwickelungsgeschichte des Pflanzenkeims. UNGER.-Fig. 26, Sitzungsberichte der Wiener Akade. mie, XLIII, and fig. 55, Anat. u. Phys. der Pflanzen. SCHACHT.-Fig's 33, 37, 44, Aratomie der Gewechse, fig's 51, 53, 54, and 62,.Der Baum, and fig's 52, 57, and 58, Die Kartoffel und ihre Krankheiten. HENFREY.-Fig's 36 and 39, Jour. Roy. Ag. Soc. of England, Vol. XIX, pp. 483 and 484. 7 oc TABLE OF CONTENTS. INTRODIUCTION...................................................... 17 DIVISION I.-CHEMICAL COMPOSITION OF THE PLANT. C(,AP. I.-THE VOLATILE PART OF PLANTS..........................2........ ~ 1. Distinctions and Defin itions.........................28 ~ 2. Elements of the Volatile Part of Plants.................31 Carboll, Hydrogen, Oxygen, Nitrogen, Sulphur, Phosphor us, Ultimate Composition of Organic Matter.............45 3. Chemical Affinity.................................46 ~ 4. Vegetable Organic Uompounds or Proximate Elements.......52 1. Water..................................... 53 2. Cellulose G r o u p.......................................55 3. Pectose "........................................81 4. Vegetable Acids........................................85 5. Fats....................................... 89 6. Albuminoids.......................................... 94 Appendix, Chlorophyll, etc............................109 CHAP. II.-THE ASH OF PLANTS............................................ 111 ~ 1. Ingredients of the Ash.......................................111 Non-metallic Elements.........................................112 Carbon and its Compounds..............................113 Sulphur ".................................114 Phosphorus" ".............................. 117 Silicon " " "..............................119 IMetallic Elements...............................................123 Potassium and its Compounds.............................124 Sodium " " "..............................124 Calcium " " "..............................125 Magnesium and its Compounds...........................126 Iron " " " 127 Manganese " " "..........................128 Salts.................................................129 Carbonates.................................................130 Sulphates......................................132 Phosphates... 3.....................................133 Chlorides...................................................13 5 Nitrates....................................................136 ~ 2. Quantity, Distribution, and Variations of the Ash............138 Table of Proportions of Ash in Vegetable Matter............ 139 i 3. Special Composition of the Ash of Agricultural Plants...... 147 1. Constant Ingredients.................................148 2. Uniform composition of normal specim's of given plant.148 Table of Ash-analyses................................150 3. Composition of Different parts of Plant...............157 4. Like composition of similar plants..................159 5. Variability of ash of same species.................i...So 6. What is normal composition of the ash of a plant?.....163 7. To what extent is each ash-ingredient essential or acci dental..............................................166 Water-culture.........................................167 Essential ash-ingredients.............................172 Is Soda Essential to Agricultural Plants?..............172 Oxide of Iron indispensable....................178 Oxide of Manganese unessential.......................179 Is chlorine indispensable?.............................180 Silica is not essential................................. 183 Ash-in gredients taken up in excess.................... 187 Disposition of superfluous matters.....................189 State of Ash-ingredients in plant......................193 ~ 4. Functions of the Ash-ingredients............................196 CaP. m. —I. Quantitative Relations among the Ingredients of Plants......201 ~ 2. Composition of the plant in successive stages of growth.....203 Composition and Growth of the Oat Plant...................204 DIVISION II.-THE STRUCTURE OF THE PLANT A6ND O6FFICES OF ITS ORGANS. CP. I.-GENERALITIES........................................ 220 Organism, Organs.........................................221 8 t f I I tI I TABLE OF CONTENTS. CHA. II.-PRIMARY ELEMENTS OF ORGANIC STRUCTURE.............2.....22 ~1. The Vegetable Cell.......................................... 222 ~2. Vegetable Tissues.........................................232 CAP. mI.-VEGETATIYE ORGANS.......................................... 234 ~1. The Root.................................................. 24 Spongioles, Root Cap.......................23 Offices of Root..............................................23F Delicacy of Structure..............................2.........23 Apparent Search for Food...................................241 Root-hairs..................................................243 Contact of Roots with Soil.................................245 Absorption by Root..........................................248 Soil Roots, Water Roots, Air Roots.....................252 Excretions..............................................258 2. The Stem....................................... 260 Buds........................................................261 Layers, Tillering.............................................264 Root-Stocks...............................................265 Tubers..................................................... 266 Structure of the Stem.......................................267 Endogenous Plants.......................................268 Exogenous.....................................273 Sieve-cells......................................280 ~ 3. Leaves...........................................................283 Leaf Pores.................................................285 Exhalation of Water Vapor..................................287 Offices of Foliage...........................................290 CAP. IV.-REPRODUCTIVE ORGANS.......................................291 ~ 1. The Flower.....................................291 Fertilization.................................................2 9 4 Hybridizin_................................................. 295 Darwin's Iypothesis........................................298 ~ 2. Fruit........................................................300 Seed..........................................302 Endosperm.................................................. 302 Embryo....................................................302 ~ 3. Vitality of seeds and their influence on the Plants they produce.305 Duration of Vitality............................... 305 Use of old. unripe and light seeds.......................307 Church's Experiments on Seed Wheat................. 308 DIVISION III.-LIFE OF THE PLANT. CRAP. I.-GERMINATION...................................................... 310 1. Introductory.................................................310 2. Phenomena of Germination.................................. 311 3. Conditions of Germination...................................312 Proper Depth of Sowing....................................316 ~ 4. Chemical Physiology of Germination........................318 Chemistry of Malt..................................... 319 CAP. II.-~ 1. Food of the Plant when independent of the Seed............327 ~ 2. The Juices of the Plant. Their Nature and Movements.....330 Flow of Sap..................................................331 Bleeding.....................................................332 Composition of Sap..........................................337 Kinds of Sap............................38 Motion of Nutrient Matters.....................340 ~ 3. Causes of Motion of the Juices...........................346 Porosity of Tissues..........................................346 Imbibition..............................................846 Capillary Attraction............................... 349 Liquid Diffusion............................................ 351 Osmose or Membrane Diffusion.............................354 Root Action.......................................... 360 Selective Power of Plant........................... 362 4. Mechanical Effects of Osmose............................... 368 ~ 5. Direction of Vegetable Growth............................. 370 APPENDIX.-TABLES. T I.-Composition of the Ash of fgricuWt'l Plants and Products. Averages.376 1* I TX I I I HOW CROPS GROW. TABLE II.-Composition of Fresh or Air-dry Agricult'l Products in 1,000 parte..381 TABLE III.-Proximate Composition of Agricultural Plants and Products.....385 TABLE IV.-Detailed Analyses of BIread Grains...............................388 TABLE V.-Detailed Analyses of Potatoes...................................389 TABLE VI.-Detailed Analyses of Sugar Beets..............................389 TABLE VII.-Composition of Fruits................................3..90 TABLE VIII.-Frmults arranged in the Order of their Content of Sugar.........393 TABLE IX.-Fruits arranged in the Order of their Content of Free Acid......393 TABLE X.-Fruits arranged according to proportions between Acid, Sugar, etc..393 TABLE XI.-Frnits arranged according to the proportions between Water, Soluble Matters, etc..............................................3)4 TABLE XIL-Proportiou of Oil in Seeds......................................394 I N D EX. Arabic acid.........................70 Arabin a........................... 70 Arendt, Estimation of sulphur and sulphuric acid.................. 195 Arendt, Study of oat-plant..........204 " Analysis of oat-plant...... 141 Argo]............................. 88 Arrow root....................... 63 Arsenic in plants............ 123, 196 Art and Science.................. 17 Artificial fecundation..............295 Ash-Ingredients...............112, 138 Excess of..........187 " " " how dis posed of..................... 189 Ash-Ingredienits, Function of, in plant..............Cace ad196 Ash-Ingredients, The indispensable.146 A o" "i State of, in plant...193 Ash of plants............... 30,111 " Analyses, Tables of.150, 876 M" " Composition of, nor mal............................16 3 Ash of plants, Composition of, va riations i n.................157, 163 Ash of oat-crop............212, 216 'i Proportions of, Tables.... 139, 145 A.. 1 " " variations in...143 Asparagus, Ash-analyses...........176 Assimilation..................... 325 Atmosphere, Offices of..........829 Atoms....................... 47 Atomic weight...................47, 48 Avenin............................ 101 Az ote of....................... 39 Bark........................ 269, 275 " Ash o f......................380 Barley, Ash-analyses.. 150, 153, 160, 378 " Proximate analyses.......... 387 Amona" "Co4 detailed..388 " Root-cap of...............236 " Root-hairs of...............244 Barley-Sl ugar.................,73 Baryta in plants...................196 Bases, Definition of............. 86 Bassorin...........................71 Bast-cells...................270, 275 Bast-Tissue...................... 233 Bayberry tallow....................91 Bean, Ash-analyses......152, 15i, 379 " Proximate analysis.......387 Absorption by the root.... 239, 250, 251 Access of air to interior of Plant... 288 Acids, Definition of................86 " Test for...................... 87 Acid elements....................2. 113 Adhesion....................... 26, 34F9 Agriculture, Art of................. 17 Agricultural products, Composition in 1,000 parts................... 381 Agricultural Science, Scope of..... 24 Experiment-Stations of Germany........... 24 Air-passages in plant.............. 289 Air-roots........................... 252 Akene............................ 301 Albumin........................... 96 Albuminoids, Characters and com position........................ 94 Albuminoids in animal nutrition...104 Diffusion of.......... 364 in oat-plant....... 211, 215 Mutual relations of...103 " Proportion of, in vege table products................. 109 Albiirnun............... 282 Alcohol from saw- dus t.............75 Aleurone.......................... 105 Algae......................... 177, 223 Alkaaali-earths....................... 125 " " Function of........... 197 " " Metals................. 125 Alkali-metals...................... 123 Alkalies........................ 86,124 " Test for.................... 87 " Function of................ 197 Alkaloids........................... 110 Alum, decomposed by diffusion... 364 Alumina............................ 129 Aluminum.......................... 129 Ammonia. Carbonate...............49 i'in plants..............108 " Salts of........137 " " in plailt..........137 Amyloids.......................... 55 " Transformation of........78 Anhydrous phosphoric acid........117 " silicic acid..............120 " sulphuric acid..........115 Anther.............................292 Apatite............................ 135 Apple, Cells of.....................2,3 x II 0 go i 14 I i II II 7 INDEX. , Cellulose, Composition.............60 " Estimation................ 60 " Group.....................55 " Test for...............59 ". Quantity of, in plants.....62 Cerasin............................ 71 Cereals, Ash-analyses of...150,,78, 379 Chaff.................................. 294 " Ash of........................ 378 Chemical affinity...................46 " " overcome by os mose...........................364 Chemical combination............. 46 "1 decomposition............ 46 Chemistry.........................26 Cherry gum........................ 1 Chlorhydric acid.................. 118 Chlorides.......................118, 135 Chloride of ammonium, decompos ed by plant.....................171 Chloride of Magnesium............118 " Potassium.............135 td'. " Sodium................136 Chlorine........................... 118 essential to crops?....180, 183 function in plant...........199 " in strand plants............183 Chlorophyll.................. 109, 285 " requires iron...........200 Church, on specific gravity of seeds.308 Circulation of sap..................330 Citric acid..........................88 Citrates............................. 136 Classes.............................298 Classification......................298 Clover, Ash of..................... 376 " soluble and insoluble ash-in gredients......................194 Clover, washed by rain............190 Coagulation....................... 96 Cochineal tincture, test for acids and alkalies........................ 87 Colloids........................... 352 Combustion........................ 35 Common Salt.....................136 Composite plants.....................300 Concentration of plant-food as.........171 Concretions in plant...............38 190 Coniferous plants..................300...3 Copper in plants............... 129, 196 Cork.......................276, 277 CForn-starch...............26 C a.1,63 Corolla............................. 292 Cotton, ash-analyses............... 156 fiber, fig............... 56, 227 " seed cake, Analysis of..378, 3821 Cotyledon.............. 268, 303 Crops, composition i 1,000 parts... 381 Coniferous plants.............. 300, 304 Crude cellulose.............. 60 Cryptogams................... 223, 299 crystalloid aleuronie................ 107 Crystalloids.......................352 Crystals in plant.............. 190, 192 Cubic centimeter................... 58 Culms............................. 262 Cyanides.......................114 Cyanogen........................114 Bean, Leaf, Section of............. 285 g" Seed.......................... 304 Beeswax........................... 91 Bee t sugar nls...... 3.................... 3 Berry............................... 301 Bicarbonate of potash.............. 130 Bicarbonate of soda................. 131 Biennial plants.................... 251 Bitartrate of potash................ 88 Bleeding of vine............... 250, 332 Blight..............................223 Blood-fibrid........................98 Bone-black........................ 32 XBon-phosphate.................... 135 Bread grains, Detailed analyses... 388 Bretschneider, Study of oat-plant... 204 Bromine t......................... 119 Brucite............................127 Buckwheat, Ash-analyses....152, 153 ............................ 163, 378 Buckwheat, Proximate analysis....387 " " " ~~~~de tailed.......................... 388 Buds, Structure of.................261 " Development under pressure.368 Bulbs..............................26 7 Butyrin............................90 Cabbage, Section of stem, fig...... 56 C'zctus senilis, Lime salt in..........191 Ct?sium............................ 125 " Action in oat.............. 196 Caffein............................. 111 Caffeotanic acid...................1 10 Calcium.......................... 125 Callous............................. 342 Calyx..............................29 2 Cambium............. 271, 272, 276, 280 Cane sugar......................... 72 Capillary attraction...............349 Caramel...........................73 Carbon, Properties o f.............31 " In ash.....................113 Carbonates......................... 130 Carbonate of lime..................131 " potash................130 " "soda..................131 Carbonic acid......................113 "' "as food of plant..... 328 " " in ash-analyses.......149 Carbonization...................32 Carrot, Ash-analyses....... 155, 156, 377 Casein.............................. 100 Cassava...........................64 C6aulerpa prolifera, fi g..............230 Causes of directive power..........371 " " motion of juices.........346 Caustic potash......................124 " soda........................125 Cauto tree......................... 183 Cell-contents....................... 228 "membrane, Thickening of..... 227 "multiplication.................. 231 "Structure of................... 224 Cells, Forms of.................... 226 " Size of....................... 230 Cellular plants..................... 223 " tissue........................ 233 Cellulose M.............5 xi I HOW CROPS GROW. Fiber in oat crop............... 210, 214 Fibrin....................... 98 Field-beet, ash-aiialyses....155, 176, 37X m" " oprox. "..............387 Flax fiber, fig.................. 56, 227 Flesh fibrin........................99 Fleshy roots.................. 251 Flower.............................291 Flow of sap........................ 331 Fluorine in plants..............119, 195 Fodder plants, Ash of............... 376 Foliage, Offices of................. 290 " white in absence of iron..199 Food of Plant.......................327 Force..................... 25 Forces............................ 26 Formative layer.................... 224 Formulas, Chemical................ 50 Fructification.................... 294 Fructose........................... 73 Fruit............................. 300 Fruits, Ash of.....................379 " Composition of.............. 390 Fruit sugar........................ 73 Fuchsia,'fi. of flower..............292 Fungi............................. 223 Gases, how distributed throughout the plant 3......................365 Gallic acid........................110 Gallotannic acid....................110 Gelatinous Silica.............. 122, 123 Gentus; Genera.................... 298 Germ...............................302 Germination.......................310 " Conditions of..........312 Chemic'l Physiology of.318 " Phenomen a o f........ 311 Temperature o f........312 Girdling.................... 342, 343, 344 Glass............................. 121 Glauber's Salt...................... 132 Gliadin............................ 101 Globulin..............97 Glucose............................74 Glucosides...................... 77, 110 Gluten.............................. 99 Gluten-Caseim...................... 100 Glycerin........................... 93 Gourd fruits....................... 301 Grains...........................301 " Ash of.......150, 378 Grain............................. 58 Grape Sugar........................ 74 Grasses, ash-analyscs.......... 157, 376 " prox. ".............. 385 Gravitation, influence on growth.... 371 Growth........................... 231 " of roots..................... 235 ' Downward and upward.....372 Gum, Amount of, in plants......... 72 Guim Arabic........................ 70 Gutm Tragacanth................ 71, 79 Guin Cotton........................ 58 Gypsum........................... 133 Gyde, Exp. on root-excretion.......259 Haberlandt, on vitality of seeds....306 Hoemozlobin........................ 97 Hallett's pedigree wheat.......,....144 Cyan ophyll............................. 110 Darwin on i nsect-fertilization...... 295 " Hypothesis of.............. 298 Decimal system of weights......... 58 Deflaoration..............................136 Definite Proportions, Law of 47 Deliquescent...................... 135 Density of seeds...... 308 Depth of sowitsg................. 316 Dextrin............................. 69 Diastase........................... 321 Dicalcic phosphate.................134 Dicotyledonous seeds.............. 303 Diffusion of liquids................ 351 Difltsion-rates...................... 352 Dicecious plants.................... 294 Direction of growth......... 30.......370 Disodic phosphate................134 Double flowers....................293 Drains stopped by roots............ 253 Druie.................................. 300 Dry weather, E ffect o f, on plants... 144 Ducts......................... 234, 272 Dundonald's treatise on Ag. Chem istry............................ 20 E lements of Matter.............. 25 Elm roots........................254 Embryo.................................. 302 Ecreulsin....................... 101 Endogfens......................... 2.38 Endogenous plants.............. 268, 303 Exosmose......................... 355 Etdosper........................ 302 Epidermis......................... 269 " of leaf..............20 -2, 287 Equi setum........................ 184 Equivalent replacement of bases...201 Eremacausis....................... 37 Estimat ion of Albuminoids........ 1.08 ' Cellulose............ 60 " " Fat.................. 94 " " Starch............66, 76 a" " Sougar............... 76 ' " ater............... 54 Etherial oils.......................... 90 Excretion of mineral matter s from leaves........................ 192 Excretions from roots............. 258 Exhalation of water from foliage ........................... 287, 332 Exogenous plants.......... 237, 273, 303 Exogens........................... 237 Exosmose.........................355 .Experiment-Stations of Germany... 24 Extension of roots.................240 Extractive Matters.................. 320 Exudation of ash-iniffredients.......189 Eyes of potato..................... 237 Families........................... 298 Fatty acids......................... 93 Fats.............................. 89 " converted into starch.......... 318 Fat in oat crop................. 211, 215 "Proportions of, in Vegetable Products................... 94 Ferments.........................327 Fertilization....................... 294 Fiber.............................. 60 Xi][ t I I INDEX. Liallier, Exp's on absorption of pig menits by plant................... 366 Hazel l eaves, loss by solution.........190 Heart-wood....................... 282 Heavy metals...................... 127 Henrici's Exp. with raspberry roots.254 Herbaceous stems..................282 Honey-dew. 76 Hooibrenk. artificial fecundation.295 Horse-chestnut, Ash-analyses of....159 Hybrid, Hybridizing...........29....529 Hydrated phosphoric acid..........117 " silica m................ 121 " sflphuric acid................... 116 Hydrate of lime.................... 126 " "magnesia.................. 127 " "potash...................124 " "soda..................... 125 Hydration of membranes................... 357 Hydrochloric acid................... 118 Hydrogr en................... 39, 112 " in Germination.......... 8 3'23 Imbibition.........................46 Imbibing power.................... 347, 348 Imbricated....................... 262 Introduction....................... 17 Inorganic matter..................... M a 29 Inter c ellular spaces................ 226 Internodes......................... 262 Inulit................ 8............68 Iodine in plants................ 119 196 " Solution of.................. 59 Iron 1.............27..... "Function of....................... 199 Isom erism................1..........81 Jerusalem Artichoke, Cell of....... 224 Juices of the Plan t.....................30 Kernel 3.............................302 Lactose............................78 Latent buds........................263 Lauws Canarienss, Air-roots of.... 257 Laurin... 9.........................90 Layers.............................264 Leached ashes......................132 Lead in plants......................196 Leaf-gree n................... 110 " pores.........................285 Leaves, Structure of...............283 office in nutrition.......... 328 of trees, Ash of............ 379 " under artificial pressure....369 Leiume........................... 301 Legumin........................... 101 Leguminous plants........... 302, 304 Legumes, ash-analyses... 152,157, 379 '"- pro. ".............. 387 Leucophyll.......................110 Levulose.. 73 Liebig on small seeds.............. 308 " " relations between N and P2 05........................ 202 Light, effect on direction of growth.375 ".".". germination........ 314 Light seeds, Plants from........... 307 Lignin.............................57 Lime............................... 126 "essential to vegettion.......172 Lime-water.....................36, 126 Linolein........................... 90 L.quid Diffusion....................8 351 Lithia, Lithium.....................125 " in plants...................195 :Litter, Ash of..................... 878 sLolilet, on vitality of seeds....... 306 Madder crop....................... 195 Magaziee, Root as.....................5 Magnetic oxide of iron............18..12 Magiesia........................... 127 "I Movements of, in oat......219 Magnesium......................... 126 Maize, ash-analyses........151, 153, 379 " prox..................... 387 " paper.............. 5........57 seed, Section of.............303 " stalk, " "............ 268 Maizeena........................... 63 Malates........................ 136 Malat e of lime....................88 Malic acid................. 88, 89 Malt, Chemistr'y of................ 319 Maltose............................75 Manganese......................... 128 " cannot replace iron...... 201 Manna............................ 77 Manniate t.............,7 r a o t p s o 78 Maple, Flow of sap from........... 332 " sugar................... 73 Margarin........................... 99 Matter.............................25 Meadow hay, Ash of................ 376 Medullary rays................... 276 Membrane-diffusion................ 354 Membranes, Inifluence on motion of juices....................... 365 Metals............................ 112 Metallic elements............ 123 Metapectic acid............. 88 Metarabic acid..................... 71 Milk ducts......................... 281 Millon's test...................... 96 Moisture, in Germination.......... 313 Molecular Weights................. 48 Molecules......................48 Monsecious plants................... 2194 Monocotyledonous seeds........... 303 Monocalcic phosphate.............. 134 Motion caused by adhesion.........350 Mould............................ 223 Mucidin........................ 101, 321 Multiple Proportions...............48 Mummy wheat.................... 305 Muriate of soda.................... 136 Muriatic acid..................... 119 Mustard, Root-hairs of............ 244 My'cose............................ 78 Myristin...........................90 Nasturtium, Cells of. 227 Nicotin..........................110 Niter, nitrate of potash. 136 Nitrates in plants.............. 10, 136 Nitrocellulose...................... 58 Nitrogen, Properties of............ 37 in ash.................... 112 " "Germination.......... 323 " relation to phosphoric acid............................ 203 .xm H0OW CROPS GROW. Pectose............................81 Pedigree wheat...............144 Permeability of cells.............. 232 Peroxide of iron...................128 Petals.............................292 Phienogams..................299 Phantom bouquets............... 57 Phloridzin........................ 77 Phosphate of lime................. 134 ' "soda................. 184 " "potash............... 1.34 Phosphates o............43, 44,117, 133 " function in plan ts............. 197 " relation to albuminoids.202 Phosphoric acid................... 38, 44, 117 " " min oat-crop..........218 Phosphorite........................ 1.35 Phosphorized oils................... 45, 92 Phosphorus................... 43,117 " in albniminoids.................102 eei" "t fats o f various plants. 92 Physics............................ 26 Physiology......................... 27 Pinite.............................. 78 Pistils...........................293 Pith...............................269 " rays.........26...................276 Plastic Elements of Nutrition...... 104 Plaster of Paris.................... 133 Plumule............................ 303 Pod................................. 301 Poll arding......................... 264 Pollen............................ 292 Polygonum convolvulus, Fertilization of, fig.......................... 295 Pome.............................. 301 Porosity of vegetable tissues.......346 Potato, ash-anialyses... 154, 162, 165, 377 " prox. analyses............. 387 " ".." detailed.......389 ultimate "............... 45 leaf, Pores of, fig............ 286 stem, Section of, fig......... 281 " sugar........................ 74 " tuber, Structure and Section of, fig.................. 274, 277 Potato tuber, why mealy...........'. 226 Potash......................... 124, 130 " lye.......................... 124 " in strand and marine plants..178 Potassium..................... 124 " Chloride of.............. 135 Prosenchyma....................... 232 Protagon...........................93 Protoplasm........................ 224 Protein bodies.................. 94,103 Protoxide of iron.................. 127 " " manganese............ 128 Proximate Composition of Crops... 385 " Elements............... 153 Prussic Acid................ 114 Ptiff-balls.........................232 Pulp of fruits...................... 223 Quack grass.............266 uantitative relations among ingre dients of plant................201 Quartz............................. 120 Quercitannic ac-d..............10 Nobbe & Siegert, Exp. on buck wheat.......................... 188 Nodes...........................262...... Nomenclature, Botanical........... 299 N on-M etals i.................... 4 112 Norton's analy ses of oat-plant..141, 204 Notation, Chemical................. 49 Nucleus....,....................422, 278 Nucleolus......................... 24 Nut...............................300 Nutrient matters in plant, Motion of.340 Nutrition of seedling ll.............. 318 Oai "mplant.................. 327 O, ash-analysi s......151..... 15, 13,lt,160 ......................2 161, 162, 378 " proxs. ".....................378 " " " detailed................. 388 crop, we ight per acre..3........87....3 plant, Composition i andgrowth of................. 204, 20P, 214, 217 Oat, proportions of ash in its differ ent parts......................... 141i Oats, weight per bushel................162 Ofices of orgians of plant.......... 220 Oil in seeds, etci.............. 89, 90, 394 "of mustard.....................114 " vitriol...................42, 116 Oils, Properties of................ S89 Old seeds, Plants from............. 307 Oleic acid..........................93 Olein........................... 90, 92 Orders............................ 298 Organic matter..................... 29 Organism........................221 Or, -ans.............................. 221 Osmose............................ Qntirli 354 " mec hanica l effects on plant..367 Osmometer........................ 355 Ovaries............................. 293 Ovules............................. 293 Oxalates........................136 Oxalate of ammonia................ 86 " lime................... 85, 86 " " " in walnut.......... 191 Oxalic acid... 85 Oxide of iron...................... 000 " " " essential to plants.... 178 " "State of, in plant...... 193 ' "manganese in ash.......179 Oxides............................. 37 of iron, described............ 127 " "manganese, described... 128 Oxygen, Properties of.............. 33 occurrence in ash......... 113 " in Assimilation............ 326 " "Germination............ 314 Palmitic acid....................... 93 Palmitin......................... 90, 92 Parenchyma....................... 232 Papilionaceous plants..............299 Pappus............................. 301 Pea, ash-analysis.......... 152, 153, 379 " prox. I I................... 387 ultimate analysis.............. 45 Pearlash........................... 130 Pectic acid....................... 82, 84 Pectin.............................. 81 llectosic acid...................... 82 KI[V e -r I I I INDEX. Saponification..................... Sautssure, exp. or mint.............187 Saxifraga crustatz.................. 192 Scotch fir, Wood-cells of, fig.........279 Scouring rush....................... 184 Screw pine, Root cap of, fi, 23 Sea-weeds, Potash in................ 198 Seed.................... S........... 302 "vessel...................O..... Seeds, constancy of composition.. 145 Selecting power of plant...... 329, 362 Sepals.............................. 292 Series............................ 298 Sesquiroxide of iron cl.................128 " " manganese......... 128 Sieve-cells......................... 280 O "o in pith...............343, 345 Silex............................120 Silica. 2............................ 120 "does not pre vent lodging of grain............I.............198 Function of, in plant..........197 " in ash.......................... 183 " oat.........................198 " textile materials............185 "unessential to plants..........183 Silicates............2................120 Silicate of potash................. 120 Silicic acid.........................120 Silicon.....................................119 Silk of maize...................... 294 Silver Fir, Roots of................245 Silver -grain........................26 Skeletonized plants................57 Soa ps.............................. 93 Soda............................... 125 " can it replace potash?........176 " essential to ag. p lants?.......1 72 in strand a nd marine plants... 17. ' Variations of, in field-crops...173 Soda-ash...........................1 31 Sodium................1.............124 " Chloride of................136 Sorghum sugar............. o......3...73 Soil, Offices of..................... 329 Soil-roots............................252 Solution of starch in Germination..322 " for water-culture.......... 168 Soluble silica....................... 121 ' starch...................... 322 Species...........................296 Spirits of salt..................... 119 -Spongioles......................... 235 Stamens............................ 292 Starch, amount in plants........... 66 " estimation..................66 " in wood.....................7 Properties o f...............63 sugar......................74 Test fr.....................64 " unorgtnized............. 64 Stearic acid..............93 Stearin........................... 90, 92 Stem, Endogenous................ 269 Exogenous................... 273 " Structure of................. 267 Stems............................. 261 Stigma............................ nercit eo........................... 78 iodicle.......................... 303 Red clover hay, Ultimate analysis 1f. 45 "beet, Pigment of...................... 367 "pine, Pith rays of..................... 276 "snow...2...................2....23 Relations of Cdllulose and Pecose Gro ups......................... 84 Relationos of Fats t o Amyloids.......................94 .." Veg. Acids to Amy loids...........................89 Reproductive Organs............ 222, 291 Rice, ash-analysis................ 151, 152, 379 " pro. -..........7..........387 " " detailed.......... 3S9 " roots of....................... 252 Rind...............................275 Ringing1 of stems................... 341 Rock Cry stal................... 120 R oot-action, imitated.................... 361 " " in winter.................. 833 S" lt Osmose in............. 360 " cap.................. s.......... crops, ash-analyses.................. 155, 377 " prox. "........ 387, 389 " cuttings...I...................27 dist inguished from stem......236 excretions................... 258 " hairs..........................243 " office in Nutrition.............327 "power of vine............... 248 " Seat of absorptive force in.... 249 " stock.......................... 265 Rootlets.............................38 Roots, Structure of................ 234 " Bursting of................. 369 " contact with soil........... 245 going down for water........2.54 " Search of food by...........241 Quantity of.................. 242 Rubidium............................ 125 ' action on oat..............196 Runners........................... 264 Rye, ash-analysis..........150,153, 379 " prox. "............387, 388 Saccharose............ 72 " Amount of, in plants.... 73 Sago................................ Steratus........................... 131 Salicin............................. 77 Salicornia...................... 117,177 Salm-Horstmar, Exp's in artificial soils.......................... 166 Sal-soda............................ 131 Salsola....................... 177,183 Salts, Definition of................. 86 " in ash of plants.............. 129 " Properties of................ 87 Saltwort............................ 177 Samphire.......................... 177 Sap..........................330 " Acid and alkaline.............366 "ascending.......340 "descending........341 "Composition of................337 "of sunflower....338 " Spring flow of..334 "' wood............... 282 x-v i N [ HOW CROPS GROW. t nripe seed, Plants from..........300 Variation of ash-ingrediel ts, limit ed......................... 147, 148 Varieti es........................... 291 " Causes of................. 144 Vascular bundle of maize stalk..... 270 Vascular-Tissue...................... 233 Vegetable acids................... 5 ' albumin.................. 97 " caselo....... l o............ " cell..................... 222 " fibrin.....9...........1....499 " ivory..................... 226 mucilage i............... 71 " parchment.............. 58 " tissue................225, 232 Vegetative organs..............222, 234 Veins of the leaf.... 285 Vine, Bleeding of.....332 Viola calamitaris................... 196 Vitality of roots...................260 " " seeds........ 305 Vital Principle..................... 221 Water,Composition o f 53 " Estimation o f. 55 Formation of 41 imbibed by roots............ 248 " "..seeds.......360 " in air-dry plants.............55 " "fresh plants 54 " of plant affected by soil......369 " vegetation, Fre e..........55 " " " Hygroscopic.. 55 Water-bath........................54 Water-ctulture......................167 Water-glass........................120 Water -oots................. 252, 253 Wax............................ 89, 9C '" in oat-plant..................211 Well-water, used in water-culture, Composition of................ 171 Wheat, ash-analyses....... 150, 152, 379 " pr,. "................ 3 " " " detailed........ 388 ultimate analyses............ 45 gum........................ 99 straw, proximate analysis...386 " " ultimate "1... 45 " roots of................ 246, 247 White of egg.......................96 Wiegmann- & Polstroff, Exp. with cress...........................146 Wilting..........................334 Wolff, Exp. with buckwheat.......164 Wood.............................. 57 "Amount of water in..........333 Ash of........................379 " cells.......................... 271 " of conifers................ 279 " paper...... 57 Wooa-fiber...... 60 "stems.............. r**Z*@282 '~ tissue................................233 Yeast.........................223, 231 Zamia spiralis, Root of............ 252 Zanthophll........................ 110 Zinc..........................129,131 Stomata.......................... 285 Stool................................265 Straw, ash-analyses........152, 153,157 " prox. ".......... 3S6 Structure of plant.................. 220 Suckers...........................266 Sugar-beet, ash-analyses....154, 156, 158 "' " detailed analyses........389 Sugar, estimation of................ 76 ill cereals.................. 7 " "sap..............3........338 of milk.............. 7......78 " Trommer's test for......... 75 Sulphate of lime..................133 " potash................132 "~ "~ soda...................132 Sulphates................... 43, 117, 132 u Function of.............. 196 '4 in clover.................. 1.94 " reduced by plant.......... 190 Sulphides....'.........4.........42 Sulphide of potassium...................115 Sulphites.......................... 115 Sulphocyanide of allyle.........11ys.. 114 Sulphur........................ 42, 114 " inl oats......................194 Sulphuireted hydrogen................43, 115 Sulphurets..................... 42 Sulphuric a cid.................. 42, 116 a" " in oat................219 Sulphurous acid................. 42, 115 Snlphydric acid................ 43, 115 Supercarbonate of soda.................131 Superphosphate of lime............ 1.35 Symbols, Chemical................. 47 T abashir........................ 183 Tannin.........................t77, 110 Tao-foo........................... 101 Tapi oca............................6 4 Tap-roots.......................... 237 Tartanic acid..................... 88, 89 Tartrates............................ 136 Tassels of maize..................2594 Te ak, Phosphate of lime in........191 Tension in plant................... 372 Tests for albuminoids...............96 Texrtile plants, Ash of..............378 Theobromin........................111 Tldaspi, var. calaminaris 196 Tillerlug...........................265 Titanic acid.................... 123, 195 Titanium.......................... 123 Tobacco, ash-analyses................ 378 u Silica in.................. 185 Touch-paper........................ 136 Tradescantia zebrina, Air-roots of.. 257 Transformations of cell-contents...229 Translocation of substances in plant....................... 218 Transplanting................... 255 Tricalcic phosphate............ 134, 135 Tubers............................. 266 Turnip, ash-analyses.......155, 156, 377 " prox. "............... 387 Tuscan hat-wheat................144 Ultimate Cgmposition of Vegeta ble Matters......................45 Umbelliferous plants.............. 2,07 'I 11 HIOW CROPS GROW. INTRODUCTION. The objects of agriculture are the production of certain plants and certain animals which are employed to feed and clothe the human race. The first aim, in all cases, is the production of plants. Nature has made the most extensive provision for the spontaneous growth of an immense variety of vegetation; but in those climates where civilization most certainly attains its fullest development, man is obliged to employ art to provide himself with the kinds and quantities of vegetable produce which his necessities or luxuries demand. In this defect, or, rather, neglect of nature, agriculture has its origin. The art of agriculture consists in certain practices and operations which have gradually grown out of an observation and imitation of the best efforts of nature, or have been hit upon accidentally. The science of agriculture is the rational theory and exposition of the successful art. Strictly considered, the art and science of agriculture are of equal age, and have grown together from the earliest times. Those who first cultivated the soil by dig 17 -.. HOW CROPS GROW. ging, planting, manuring, and irrigating, had their sufficient reason for every step. In all cases, thought goes before work, and the intelligent workman always has a theory upon which his practice is planned. No farm was ever conducted without physiology, chemistry, and physics, any more than an aqueduct or a railway was ever built without mathematics and mechanics. Every successful farmer is, to some extent, a scientific man. Let him throw away the knowledge of facts and the knowledge of principles which constitute his science, and he has lost the elements of his success. The farmer without his reasons, his theory, his science, can have no plan; and these wanting, agriculture would be as complete a failure with him as it would be with a man of mere science, destitute of manual, financial, and executive skill. Other qualifications being equal, the more advanced and complete the theory of which the farmer is the master, the more successful must be his farming. The more he knows, the more he can do. The more deeply, comprehensively, and clearly he can think, the more economically and advantageously can he work. That there is any opposition or conflict between science and art, between theory and practice, is a delusive error. They are, as they ever have been and ever must be, in the fullest harmony. If they appear to jar or stand in contradiction, it is because we have something false or incomplete in what we call our science or our art; or else we do not perceive correctly, but are misled by the narrowness and aberrations of our vision. It is often said of a machine, that it was good in theory, but failed in practice. This is as untrue as untrue can be. If a machine has failed in practice, it is because it was imperfect in theory. It should be said of such a failure-the machine was good, judged by the best theory known to its inventor, but its incapacity to work demonstrates that the theory had a flaw. But, although art and science are thus inseparable, it 18 i I INTRODUCTION. must not be forgotten that their growth is nrt altogether parallel. There are facts in art for which science can, as yet, furnish no adequate explanation. Art, though no older than science, grew at first more rapidly in vigor and in stature. Agriculture was practised hundreds and thousands of years ago, with a success that does not compare unfavorably with ours. Nearly all the essential points of modern cultivation were regarded by the Romans before the Christian era. The annals of the Chinese show that their wonderful skill and knowledge were in use at a vastly earlier date. So much of science as can be attained through man's unaided senses, reached considerable perfection early in the world's history. But that part of science which relates to things invisible to the unassisted eye, could not be developed until the telescope and the microscope had been invented, until the increasing experience of man and his improved art had created and made cheap the other inventions by whose aid the mind can penetrate the veil of nature. Art, guided at first by a very crude and imperfectly developed science, has, within a comparatively recent period, multiplied those instruments and means of research whereby science has expanded to her present proportions. The progress of agriculture is the joint work of theory and practice. In many departments great advances have been made during the last hundred years; especially is this true in all that relates to implements and machines, and to the improvement of domestic animals. It is, however, in just these departments that an improved theory has had sway. More recent.is the development of agriculture in its chemical and physiological aspects. In these directions the present century, or we might almost say the last 30 years, has seen more accomplished than all previous time. The first book in the English language on the subjects which occupy a good part of the following pages, was written by a Scotch nobleman, the Earl of Dundonald, and I 11 19 tIOW CRoPS GROW. was published at London in 1795. It was entitled: "A Treatise showing the Intimate Connection that subsists between Agriculture and Chemistry." The learned Earl in his Introduction remarked that "the slow progress which agriculture has hitherto made as a science is to be ascribed to a want of education on the part of the cultivators of the soil, and the want of knowledge in such au thors as have written on agriculture, of the intimate connection that subsists between the science and that of chemistry. Indeed, there is no operation or process, not merely mechanical, that does not depend on chemistry, which is defined to be a knowledge of the properties of bodies, and of the effects resulting from their different combinations." Earl Dundonald could not fail to see that chemistry was ere long to open a splendid future for the ancient art that always had been and always is to be the prime support of the nations. But when he wrote, no longer than seventy-two years ago, how feeble was the light that chemistry could throw upon the fundamental questions of agricultural science! The chemical nature of atmospheric air was then a discovery of barely 20 years' standing. The composition of water had been known but 12 years. The only account of the composition of plants that Earl Dundonald could give, was the following: "Vegetables consist of mucilaginous matter, resinous matter, matter analogous to that of animals, and some proportion of oil. * * Besides these, vegetables contain earthy matters, formerly held in solution in the newly taken-in juices of the growing vegetable." To be sure he explains by mentioning on subsequent pages that starch belongs to the mucilaginous matters, and that, on analysis by fire, vegetables yield soluble alkaline salts and insoluble phosphate of lime. But these salts, he held, were formed in the process of burning, their lime excepted, and the fact of their being taken from the soil and constituting the indispensable food of plants, his Lordship was unac II 2) INTRODUCTIO0N. quainted with. The gist of agricultural chemistry with him was, that plants are "composed of gases with a small proportion of calcareous matter;" for "although this discovery may appear to be of small moment to the practical farmer, yet it is well deserving of his attention and notice, as it throws great light on the nature and food of vegetables." The fact being then known that plants absorb carbonic acid from the air, and employ its carbon in their growth, the theory was held that fertilizers operate by promoting the conversion of the organic matter of the soil or of composts into gases, or into soluble humus, which were considered to be the food of plants. The first accurate analysis of a vegetable substance was not accomplished until 15 years after the publication of Dundonald's Treatise, and another like period passed before the means of rapidly multiplying good analyses had been worked out by Liebig. So late as 1838, the Gottingen Academy offered a prize for a satisfactory solution of the then vexed question whether the ingredients of ashes are essential to vegetable growth. It is, in fact, during the last 30 years that agricultural chemistry has come to rest on sure foundations. Our knowledge of the structure and physiology of plants is of like recent development. What immense practical benefit the farmer has gathered from this advance of science! The dense populations of Great Britain, Belgium, Holland, and Saxony, can attest the fact. Chemistry has ascertained what vegetation absolutely demands for its growth, and points out a multitude of sources whence the requisite materials for crops can be derived. To be sure, Cato and Columella knew that ashes, bones, bird-dung and green manluringl, as well as drainage and aeration of the soil, were good for crops; but that carbonic acid, potash, phosphate of lime, and com pounds of nitrogen, are the chief pabulum of vegetation, they did not know. They did not know that the atmos. phere dissolves the rocks, and converts inert stone into 21 HOW CROPS GROW. nutritive soil. These grand principles, understood in many of their details, are an inestimable boon to agriculture, and intelligent farmers have not been slow to apply them in practice. The vast trade in phosphatic and Peruvian guano, and in nitrate of soda; the great manufactures of oil of vitriol, of superphosphate of lime, of fish fertilizers; and the mining of fossil bones and of potash salts, are largely or entirely industries based upon and controlled by chemistry in the service of agriculture. Every day is now the witness of new advances. The means of investigation, which, in the hands of the scientific experimenter, have created within the writer's memory such arts as photography and electro-metallurgy, and have produced the steam engine and magnetic telegraph, are working and shall continue to work progress in agriculture. This improvement will not consist so much in any remarkable discoveries that shall enable us "to grow two blades of grass where but one grew before," but in the gradual disclosure of the reasons of that which we have long known, or believed we knew, in the clear separation of the true from the seemingly true, and in the exchange of a wearying uncertainty for settled and positive knowledge. It is the boast of some who affect to glory in the sufficiency of practice and decry theory, that the former is based upon experience, which is the only safe guide. But this is a one-sided view of the matter. Theory is also based upon experience, if it be truly scientific. The vagarizingr of an ignorant and undisciplined mind is not theory. Theory, in the good and proper sense, is always a deduction fi'om facts, the best deduction of which the stock of facts in our possession admits. It is the interpretation of facts. It is the expression of the ideas which facts awaken when submitted to a fertile imagination and well-balanced judgment. A scientific theory is intended for the nearest possible approach to the truth. Theory is confessedly im I 22 t INTRODUCTIOTN. perfect, because our knowledge of facts is incomplete, our mental insight weak, and our judgment fallible. But the scientific theory which is framed by the contributions of a multitude of earnest thinkers and workers, among whom are likely to be the most gifted intellects and most skillful hands, is, in these days, to a great extent worthy of the Divine truth in nature, of which it is the completest human conception and expression. Science employs, in effecting its progress, essentially the same methods that are used by merely practical men. Its success is commonly more rapid and brilliant, because its instruments of observation are finer and more skillfully handled; because it experiments more industriously and variedly, thus commanding a wider and more fruitful experience; because it usually brings a more cultivated imagination and a more disciplined judgment to bear upon its work. The devotion of a life to discovery or invention is sure to yield greater results than a desultory application made in the intervals of other absorbing pursuits. It is then for the interest of the farmer to avail himself of the labors of the man of science, when the latter is willing to inform himself in the details of practice, so as rightly to comprehend the questions which press for a solution. It is characteristic of our time that large associations of practical agriculturists have recognized the immediate pecuniary advantage to be derived from the application of science to their art. This was first done at Edinburgh, in 1843, by the establishment Of the "Agricultural Chemistry Association of Scotland." This organization limited itself to a duration of five years. At the expiration of that time, its labors, which had been ably conducted by Prof. James F. W. Johnston, were assumed by the Hig,hland and Agricultural Society of Scotland, and have been prosecuted up to the present day by Dr. Anderson. The Royal Ag'l Soc. of England began to employ a consulting chemist, Dr. Lyon Playfair, in 1843; and since 1848 most valuable investigations, by Prof. Way and Dr. Veleker, have regularly appeared in its journal. Other British Ag'l Societies have followed these examples with more or less effect. It is, however, in Germany that the most extensive and well-organized efforts have been made by associations of agriculturists to help their 23 HOW CROPS GROW. practice by developirng theory. In 1851 the Agricultural Society of Leip zig, (Leipziger Oeconomische Societcet), established an Ag'l Experi'nent Station on its farm at Moeckern, near that city. Thlis example was soon imitated in other parts of Germany and the neighboring countries; and at the present writing, 1867, there are of similar Experilmlent Stations in operation-in Prussia 10, in Saxony 4, in Bavaria 3, in Austria 3, in Brunswick, Hesse, Tharingia, Anhalt, Wirtemberg, Baden, and Sweden, 1 each, making a total of 26, chiefly sustained by, and operating in, the interest of the agriculturists of those countries. These stations give constant employment to 60 chemists and vegetable physiologists, of whom a large number are occupied largely or exclusively with theoretical investigations, while the work of others is devoted to more practical matters, as testing the value of commercial fertilizers. Since 1859 a journal, Die Latdwirthschaftlichen Versuchs-Stationen, (Ag'l Exp. Stations), has been published as the organ of these establishments, and the 9 volumes now completed, together with the numerous Reports of the Stations themselves, have largely contributed the facts that are made use of in the following pages. In this country some similar enterprises have been attempted, but have not been supported with a sufficient combination of talent and pecuniary outlay to ensure any striking success in the direction of agricultural chemistry. An imitation of the example set by European associations is well worthy the consideration of our State Ag'l Societies, many of which could easily command the funds for such an enterprise. It would be found that such a use of their resources would speedily strengthen their hold on the interest and regard of the communities they represent. Agricultural science, in its widest scope, comprehends a vast range of subjects. It includes something firom nearly every department of human learning. The natural sciences of geology, meteorology, mechanics, physics, chemistry, botany, zoology and physiology, are most intimately related to it. It is not less concerned with social and political economy, with commerce and law. In the treatises of which this is the first, it will not be attempted to cover nearly all this ground, but some account will be given of certain subjects whose understanding promises to be of the most direct service to the agriculturist. The theory of agriculture, as founded on chemical, physical, and physiological science, is the topio of this and the succeeding volume. 24 INTRODUCTION. Some preliminary propositions and definitions may be serviceable to the reader. Science deals with matter and force. Matter is that which has weight and bulk. Force is the cause of changes in matter-it is appreciable only by its effects upon matter. Force resides in and is inseparable firom matter. Force manifests itself in motion. All matter is perpetually animated by force-is therefore never at rest. What we call rest in matter is simply motion too fine for our perceptions. The different kinds of matter known to science have been resolved into not more than 62 elements or simple substances. Elements, or ultimate elements, are forms of matter which have thus far resisted all attempts at their simplification. In ordinary life we commonly encounter but 12 elements in their elementary state, viz.: Oxygen, Nitrogen, Sulphur, Carbon, Iron, Zinc, The numberless other substances with which we are familiar, are mostly compounds of the above, or of 12 other elements, viz.: Hydrogen, - Phosphorus, Chlorine, Silicon, Potassium, Sodium, 2 25 Mercury, Copper, Lead, Tin, Silver, Gold. Calcium, Mao,nesium, Aluminum, Manganese, Chromium, Nickel. HOW CROPS GROW. We distinguish a number of forces, which, acting on or through matter, produce all material phenomena. In the subjoined scheme the recognized forces are to some extent classified and defined, in a manner that may prove useful to the reader. Act at sensi- Repl sive LIGHT Radiant ble and in- Repulsive HEAT ble and in- { Attrat-[aiant sensible Att rac tive ELECTRICITY Inductive distances and R MAGNETISM Inductve Repulsive GRAVITATION CosmicaP1 COHESION Act only at CRYSTALLIZATION insensible Attractive ADHESION Molecular distances OLUTION IOSMOSE1 AFFINITY Atomic VITALITY Organic The sciences that more immediately relate to agriculture are: 1.-Physics or natural philosophy,-the science which considers the general properties of matter and such of its phenomena as are not accompanied by essential change in its obvious qualities. All the forces in the preceding scheme, save the last two, manifest themselves through matter without destroying or masking the matter itself. Iron may be hot, luminous, or magnetic, may fall to the ground, be melted, welded, and crystallized; but it remains iron, and is at once recognized as such. Thie forces whose play does not disturb the evident characters of substances are physical. II.-Chemistry,-the science which studies the properties peculiar to the various kinds of matter, and those phenomena which are accompanied by a fundamental zhange in the matter acted on. Iron rusts, wood burns, and both lose all the external characters that serve for their identification. They are, in fact, converted into other substances. Affinity, or chemical affinity, unites two or more elements into compounds, unites compounds together ito more complex oompounds; and, under the influence of 26 I Chemical Physiolo,,ical INTRODUCTION. o heat, light, and other agencies, is annulled or overcome, so that compounds resolve themselves into simpler combina tions.or into their elements. Chemistry is the science of composition and decomposition; it considers the laws and results of affinity. III.-Physiology, which unfolds the laws of the devel opment, sustenance, and death, of living organisms. When we assert that the object of agriculture is to develop from the soil the greatest possible amount of certain kinds of vegetable and animal produce at the least cost, we suggest the topics which ore most important for the agriculturist to understand. The farmer deals with the plant, with the soil, with manures. These stand in close relations to each other, and to the atmosphere which constantly surrounds and acts upon them. How the plant grows,-the conditions under which it flourishes or suffers detriment,-the materials of which it is made,-the mode of its construction and organization,-how it feeds upon the soil and air, —how it serves as food to animals,-how the air, soil, plant, and animal, stand related to each other in a perpetual round of the most beautiful and wonderful transformations,these are some of the grand questions that come before us; and they are not less interesting to the philosopher or man of culture, than important to the farmer who depends upon their practical solution for his comfort; or to the statesman, who regards them in their bearings upon the weightiest of political considerations. 27 I DIVISION CHEMICAL COMPOSITION OF THE PLANT. CHAPTER I. THE VOLATILE PART OF PLANTS. ~ 1. DISTINCTIONS AND DEFINITIONS. ORGANIC AND INORGANIC MAITER.-All matter may be divided into two great classes- Organic and Inorganic. Organic matter is the product of growth, or of vital organization, whether vegetable or animal. It is mostly combustible, i. e., it may be easily set on fire, and burns away into invisible gases. Organic matter either itself constitutes the organs of life and growth, and has a peculiar organized structure, inimitable by art,-is made up of cells, tubes or fibres, (wood and flesh); or else is a mere result or product of the vital processes, and destitute of this structure (sugar and fat). All matter which is not a part or product of a living organism is inorgqanic or mineral matter (rocks, soils, water, and air). Most of the naturally occurring forms of inorganic matter which directly concern agricultural chemistry are incombustible, and destitute of anything like organic structure. By the processes of combustion and decay, organic matter is disorganized or converted into inorganic matter, while, on the contrary, by vegetable growth inorganic matter is organized, and becomes organic. 29 I. HOW CROPS GROW. Organic matters are in general characterized by complexity of constitution, and are exceedingly numerous and various; while inorganic bodies are of simpler composition, and comparatively few in number. VOLATILE AND FIXED MATrER.-All plants and animals, taken as a whole, and all of their organs, consist of a volatile and a fixed part, which may be separated by burning; the former-usually by far the larger share-passing into, and mingling with the air as invisible gases; the latterforming, in general, but from one to five per cent of the whole-remaining as ashes. EXPERIMENT 1.-A splinter of wood heated in the flame of a lamp takes fire, burns, and yields volatile matter, which consumes with flame, and ashes, which are the only visible residue of the-combustion. MIany organic bodies, products of life, but not essential vital organs, as sugar, citric acid, etc., are ceopletely volatile when in a state of purity, and leave no ash. CURRENT USE OF THE TERMS ORGANIC AND INORGANIC.-It is usual among agricultural writers to confine the term organic to the volatile or destructible portion of vegetable and animal bodies, and to designate their ash-ingredients as inorganic matter. This use of the words is extremely inaccurate. What is found in the ashes of a tree or of a seed, in so far as it was an essential part of the organism, was as truly organic as the volatile portion, and by submitting organic bodies to fire, they may be entirely converted into inorganic matter, the volatile as well as the fixed parts. ULTIMATE ELEMENTS THAT C0InSTITUTE THE PLANT.Chemistry has demonstated that the volatile and destructible part of organic bodies is made up chiefly of four substances, viz.: carbon, oxygen, hydrogen, and nitrogen, and contains two other elements in lesser quantity, viz.: sulphur and phosphorus. In the ash we may find phosphorus, sulphur, silicon, chlorine, potassium, sodium, cal 30 THE VOLATILE PART OF PLANTS. cium, magnesium, iron, and manganese, as well as oxygen, carbon, and nitrogen.* These fourteen bodies are elements, which means in chemical language, that they cannot be resolved into other substances. All the varieties of vegetable and animal matter are compozunds,-are composed of and may be resolved into these elements. The above fourteen elements being essential to the organism of every plant and animal, it is of the highest importance to make a minute study of their properties. ~ 2. ELEMENTS OF THE VOLATILE PART OF PLANTS. For the sake of convenience we shall first consider the elements which constitute the destructible part of plants, viz.: Carbon, Hydrogen, Oxygen, Sulphur, Nitrogen, Phosphorus. The elements which belong exclusively to the ash will be noticed in a subsequent chapter. Carbon, in the free state, is a solid. We are familiar with it in several forms, as lampblack, charcoal, anthracite coal, black-lead, and diamond. Notwithstanding the substances just named present great diversities of appearance and physical characters, they are identical in a certain chemical sense, as by burning they all yield the same product, viz.: carbonic acid gas. That carbon constitutes a large part of plants is evident fi'om the fact that it remains in a tolerably pure state after the incomplete burning of wood, as is illustrated in the preparation of charcoal. - * Rarely, or to a slight extent, lithium, rubidium, iodine, bromine, fliuoro barium, copper, zinc, and titanium. 31 HOW CROPS GROW. ExP. 2.-If a splinter of dry pire wood be set on fire and thie burning end be gradually passed into the mouth of a narrow tube, (see figure 1,) whereby the supply of air is cut off, or if it be thrust into sand, the burning is incomplete, and a stick of charcoal remains. Carbonization and charring are terms used to express the blackening of organic bodies by heat,! and are due to the separation of carbon in the free or uncombined state. The presence of carbon in animal matters also is shown by subjecting them to incomplete com- I bustion. Exr. 3.-Hold(l a knife-bla.de in the flame of a tallow candle; the full access of air is thus prevented,-a portion of cai bon escapes combustion, and is deposited on the blade in the form Fig. 1. of lamp-black. Oil of turpentine and petroleum (kerosene,) contain so much carbon that a portion escapes in the free state as smoke, when they are set on fire. When bones are strongly heated in closely covered iron pots, until they cease yielding any vapors, there remains in the vessels a mixture of impure carbon with the earthy matter (phosphate of lime) of the bones, which is largely used in the arts, chiefly for refining sugar, but also in the manufacture of fertilizers under the name of animal charcoal, or bone-black. Lignite, bituminotus coal, coke-the porous, hard, and lustrous mass left when bituminous coal is heated with a limited access of air, and the metallic appearing gas-carbon that is found lining the iron cylinders in which illuminating coal-gas is prepared, consist chiefly of carbon. They usually contain more or less incombustible matters, as well as oxygen, hydrogen, and nitrogen. The different forms of carbon possess a greater or less degree of porosity and hardness, according to their origin and the temperature at which they are prepared. Carbon, in most of its forms, is extremely indestructible, 32 THE YOLATILE PART OF PLANTS. unless exposed to an elevated temperature. Hence stakes and fence posts, if charred before setting in the ground, last longer than when this treatment is neglected. The porous varieties of carbon, especially wood charcoal and bone-black, have a remarkable power of absorbing gases and coloring matters, which is taken advantage of in the refining of sugar. They also destroy noisome odors, and are therefore used for purposes of disinfection. Carbon is the characteristic ingredient of all organic compounds. There is no single substance that is the exelusive result of vital organization, no ingredient of the animal or vegetable produced by their growth, that does not contain this element. Oxygen.-Carbon is a solid, and is recognized by our senses of sight and feeling. Oxygen, on the other hand, is invisible, odorless, tasteless, and not distinguishable in any way from ordinary air by the unassisted senses. It is an air or gas. It exists in the free (uncombined) state in the atmosphere we breathe, but there is no means of obtaining it pure except from some of its compounds. Many metals unite readily with oxygen, forming compounds (oxides) which by heat separate again into their ingredients, and thus furnish the means of procuring pure oxygen. Iron and copper when strongly heated and exposed to the air acquire oxygen, but from the oxides of these metals (forge cinder, copper scale,) it is not possible to separate pure oxygen. If, however, the metal mercury (quicksil ver) be kept for a long time at a boiling heat, it is slowly converted into a red powder (red precipitate or oxide of mercury), which on being more strongly heated is decomposed, yielding metallic mercury and gaseous oxygen in a pure state. The substance usually employed as the most convenient source of oxygen gas is a white salt, the chlorate of pot 2* 33 HO1W CROPS GROW. ash. Exposed to heat, this body melts, and presently evolves oxygen in great abundance ExP. 4.-The following figure illustrates the apparatus employed for preparing, and collecting this gas. A tube of difficultly fusible glass, 8 inches long and s inch wide, contains the ox,de of mercury or chlorate of potash.* To its mouth is connected, air-tight, by a cork, a narrow tube, the free extremity of which passes under the shelf of a tub nearly filled with water. The shelf has beneath, a sauc(er-shaped cavity opening above by a narrow orifice, over which a bottle filled with water is inverted. Heat being applied to the wide tube, the common air it contains is first expelled, and presently, oxygen bubbles rapidly into the bottle and displaces the water. When the bottle is full, it may be corked and set aside, and its place supplied by another. Fill four pint bottles with the gas, and set them aside with their mouths in tumblers of water. From one ounce of chlorate of potash about a gallon of oxygen gas may be thus obtained, which is not quite pure at first, but becomes nearly so on standing over water for some hours. When the escape of gas becomes slow and cannot be quickened by increased heat, remove the delive-ry-tube firom the water, to prevent the latter receding and breaking the apparatus. * The chlorate of potash is best mixed with about one-quarter its weight of powdered black oxide of manganese, as this facilitates the preparation, and renders the heat of a common spirit lamp sufficient. 3-1 I A I THE VOLATILE PART OF PLANTS. As this gas makes no peculiar impressions on the senses, we employ its behavior towards other bodies for its recognition. Exp. 5.-Place a burning splinter of wood in a vessel of oxygen (lifted f ri that purpose, mouth upward, from the water). The flune is at once greatly increased in brilliancy. Now remove the splinter from the bottle, blow out the flame, and thrust the still glowing point into the oxygen. It is instantly relighted. The experiment m.av h. repeated many times. This is the usual test for oxygen gas. Combustion. —When the chemical union of two bodies takes place with such energy as to produce visible phenomena of fire or flame, the process is called combustion. Bodies that burn are combustibles, and the gas in which a substance burns is called a supporter of combustion. Oxygen is the grand supporter of combustion, and all the cases of burning met with in ordinary experience are instances of chemical union between the oxygen of the atmosphere and some other body or bodies. The rapidity or intensity of combustion depends upon the quantity of oxygen and of the combustible that unite within a given time. Forcing a stream of air into a fire increases the supply of oxygen and excites a more vigorous combustion, whether it be done by a bellows or result from ordinary draught. Oxygen exists in our atmosphere to the extent of about one-fifth of the bulk of the latter. When a burning body is brought into unmixed oxygen, its combustion is, of course, more rapid than in ordinary air, four-fifths of which is a gas, presently to be noticed, that is nearly indifferent in its chemical affinities toward most bodies. In the air a piece of burning charcoal soon goes out; but if plunged into oxygen, it burns with great rapidity and brilliancy. Exr. 6.-Attach a slender bit of charcoal to one end of a sharpened wire that is passed through a wide cork or card; heat the charcoal to redness in the flame of a lamp, and then insert it into a bottle cf oxygen, 35 HOLW CROPS GROIN. fir 3. When the combustion has declined, a suitable test app]ied to the air of the bottle will demoustrate that another invisible gas has taken the place of the oxygen. Snch a test is hmeweter.* On pouring some of this into the bottle and agitating vigorously, the previously clear liquid becomes milky, and on standing, a white deposit, or predpitete, as the ~, chemist terms it, gathers at the bottom of the vessel. Li:1>) Carbon, by thus uniting to oxygen, yields carbonic acid gas, which in its turn combines with lime, producing carbona of lime. These substauces will be further Ii noticed in a subsequent chapter. __ Metallic'eon is incombustible in the at3 mosphere under ordinary circumstances but Fig if heated to redness and brought into pure oxygen gas, it burns as readily as wood burns in the air. Exp. 7.-Provide a thin knitting needle, beat one end red hot and match, X inch long;) pass the other end of the needle through a wide, fiat cork for a support, set the wood on fire, and immerse the needle in a bottle of oxygen, fig. 4. After the wood consumes, the iron itself takes fire and burns with vivid scintillations. It is converted {i! into oxide of ii-on, a part of which will be found as a i yellowish-red coating on the sides of the bottle; the remainder will fuse to black, brittle globules, which falling, often melt quite into the glass. Fig. 4. The only essential difference between these and ordinary cases of combustion is the intensity with which the process goes on, due to the more rapid access of oxygen to the combustible. Many bodies unite slowly with oxygen-oxidize, as it is termed,-without these phenomena of light and intense heat which accompany combustion. Thus iron rusts, lead tarnishes, wood decays. All these processes are cases of oxidation, and cannot go on in the absence of oxygen. Since the action of oxygen on wood and other organic * To prepare lime-water, put a piece of unslaked lime, as large as a chestnut, into a pint of water, and after it has fallen to powder, agitate the whole for a minute in a well stoppered bottle. On standing, the excess of lime will settle, and the perfectly clear liquid above it is ready for use. 36 THE VOLATILE P kRT OF PLANTS. matters at common temperatures is strictly analogous in a chemical sense to actual burning, Liebig has proposed the term eremacausis, (slow burningr), to designate the chemical process which takes place in decay and putrefaction, and which is concerned in many transformations, as in the making of vinegar and the formation of saltpeter. Oxygen is necessary to organic life. The act of breathing introduces it into the lungs and blood of animals, where it aids the important office of respiration. Animals, and plants as well, speedily perish if deprived of firee oxygen, which has therefore been called vital air. Oxygen has a universal tendency to combine with other substances, and form with them new compounds. With carbon, as we have seen, it forms carbonic acid. With iron, it unites in various proportions, giving origin to several distinct oxides, of which iron-rust is one, and anvilscales another. In decay, putrefaction, fermentation, and respiration, numberless new products are formed, the results of its chemical affinities. Oxygen is estimated to be the most abundant body in nature. In the free state, but mixed with other gases, it constitutes one-fifth of the bulk of the atmosphere. In chemical union with other bodies, it forms eight-ninths of the weight of all the water of the globe, and one-third of its solid crust-its soils and rocks,-as well as of all the plants and animals which exist upon it. In fact there are but few compound substances occurring in ordinary experience into which oxygen does not enter as a necessary ingredient. Nitrogen.-This body is the other chief constituent of the atmosphere, in which its office might appear to be mainly that of diluting and tempering the affinities of oxygen. Indirectly, however, it serves other most important uses, as will presently be seen. For the preparation of nitrogen we have only to remove the oxygen firom a portion of atmospheric air. This may 37 HOW CROPS GROW. be accomplished more or less perfectly by a variety of methods. We have just learned that the process of burning is a chemical union of oxygen with the combustible. If, now, we can find a body which is very combustible and one which at the same time yields by union with oxygen a product that may be readily removed from the air in which it is formed, the preparation of nitrogen from ordinary air becomes easy. Such a body is phosphorus, a substance to be noticed in some detail presently. Exp. 8.-The bottom of a dinner-plate is covered half an inch deep with water, a bit of chalk hollowed out into a little cup is floated on the water by means of a large flat cork or a piece of wood; into this cup a morsel of dry phosphorus as large as a pepper-corn is placed, which is then set on fire and covered by a capacious glass bottle or bell jar. The phosphorus burns at first with a vivid light, which is presently obscured by a cloud of snow-like phosphoric acid. The combustion goes on, however, until nearly all the oxygen is removed from the included air. The air is at first ex- panded by the heat of the flame, and a portion of it es — capes from the vessel; afterward it diminishes in volume Fil 5 as its oxygen is removed, so that it is needful to pour water on the plate to prevent tie external air from passing into the vessel. After some time the white fume will entirely fall, and be absorbed by the water, leaving the inclosed nitrogen quite clear. Exp. 9.-Another instructive method of preparing nitrogen is the following: A handful of copperas (sulphate of protoxide of iron) is dissolved in half a pint of water, the solution is put into a quart bottle, a gill of liquid ammonia or fresh potash lye is added, the bottle stoppered, and the mixture vigorously agitated for some minutes; the stopper is then lifted, to allow fresh air to enter, and the whole is again agitated as before; this is repeated occasionally for half an hour or more, until no further absorption takes place, when nearly pure nitrogen remains in the bottle. Free nitrogen, under ordinary circumstances, has scarcely any active properties, but is best characterized by its chemical indifference to most other bodies. That it is incapable of supporting combustion is proved by the first method we have instanced for its preparation. Exp. 10.-A burning splinter is immersed in the bottle containing the nitrogen prepared by the second method, Exp. 9; the flame immediately goes out. 38 THE VOLATILE PART OF PLANTS. Nitrogen cannot maintain respiration, so that animals perish if confined in it. For this reason it was formerly called Azote (against life). Decay does not proceed in an atmosphere of this gas, and in general it is difficult to effect its direct union with other bodies. At a high temperature, especially in presence of baryta, it unites with carbon, forming cyanogen-a compound existing ill Prussian-blue. The atmosphere is the great store and source of nitrogen in nature. In the mineral kingdom, especially in soils, it occurs in small quantity as an ingredient of saltpeter and ammonia. It is a small but constant constituent of all plants, and in the animal it is a never-failing component of the working tissues, the muscles, tendons and nerves, and is hence an indispensable ingredient of food. Hydrogen.-Water, which is so abundant in nature, and so essential to organic existence, is a compound of two elements, viz.: oxygen, that has already been considered, and hydrogen, which we now come to notice. Hydrogen, like oxygen, is a gas, destitute, when pure, of either odor, taste, or color. It does not occur naturally in the free state, except in small quantity in the emanations from boiling springs and volcanoes. Its preparation almost always consists in abstracting oxygen from water by means of agents which have no special affinity for hydrogen, and therefore leave it uncombined. Sodium, a metal familiar to the chemist, has such an attraction for oxygen that it decomposes water with great rapidity. ExP. 11.-Hydrogen is therefore readily procured by inverting a bottle full of water in a bowl, and inserting into it a bit of sodium as large as a pea. The sodium must first be wiped free from the naphtha in which it is kept, and then be wrapped tightly in several folds of paper. On bringing it, thus prepared, under the mouth of the bottle, it floats upward, and when the water penetrates the paper, an abundant escape of gas occurs. Metallic iron and zinc decompose water, uniting with 39 I H ioV CROPS GROW. oxygen and setting hydrogen free. This action is almost imperceptible, however, with pure water under ordinary circumstances, because the metals are soon coated with a film of oxide which prevents further contact. If to the water a strong acid be added, or, in case zinc is used, an alkali, the production of hydrogen goes on very rapidly, because the oxide is dissolved as fast as it forms, and a perfectly pure metallic surface is constantly presented to the water. Exp. 12.-Into a bottle fitted with co:'k, funnel, and delivery tubes, fig. 6, an ounce of iron tacks orzinc clippings is introduced, a gill of water is poured upon them, and lastly an ounce of oil of vitriol is added. A brisk effervescence shortly commences, owing to the escape of nearly pure hydrogen gas, which may be collected in a bottle filled with water as directed for oxygen. The first portions that pass over are mixed with air, and should be rejecled, as the mixture is dangerously explosive. One of the most striking properties of free hydrog~en is its levity. It := hydrogen is its levity. It is the lightest body in nature, being fourteen and a half times lighter than common air. It is hence used in filling balloons. ....:Another property is its combustibili ty; it inflames on contact with a I 1 / ~ lighted taper, and burns with a flame which is intensely hot, though scarce ly luminous if the gas be pure. Final * —y~ ~ ly, it is itself incapable of support Fig. 7. ing the combustion of a taper. Exp. 13.-All these characters may be shown by the following single experiment. A bottle full of hydrogen is lifted from the water over which it has been collected, and a taper attached to a bent wire, fig. 7, is 40 Fi,. 6. THE VOLATILE PART OF PLANTS. brought to its mouth. At first a slight explosion is heard from the sudden burning of a mixture of the gas with air that forms at the mouth of the vessel; then the gas is seen burnting on its lower surface with a pale flame. If now the taper be passed into the bottle it will be extinguished; on lowering it again, it will be relighted by the burning gas; finally, if the bottle be suddenly turned mouth upwards, the light hydrogen rises in a sheet of flame. In the above experiment, the hydrogen burns only where it is in contact with atmospheric oxygen; the product of the combustion is an oxide of hydrogen, the univelrsally diffused compound, water. The conditions of the experiment do not permit the collection or identification of this water; its production can, however, readily be demonstrated. Exr. 14.-The arrangement shown in fig. 8 may be employed to exhibit the formation of water by the burning of hydrogen. Hydrogen gas is generated from zinc and dilute acid in the two-necked bottle. Thus produced, it is mingled with vapor of water, to remove which it Fig. 8. is made to stream slowly through a wide tube filled with fragments of dried chloride of calcium, which desiccates it perfectly. After air has been entirely displaced firom the apparatus, the gas is ignited at the upcurved end of the narrow tube, and a clean bell-glass is supported over the flame. Water collects at once, as dew, on the interior of the bell, and shortly flows down in drops into a vessel placed beneath. In the mineral world we scarcely find hydrogen occurring in much quantity, save as water. It is a constant ingredient of plants and animals, and of nearly all the numberless substances which are products of organic life. 41 II HOW CROPS GROW. Hydrogen forms with carbon a large number of compounds, the most common of which are the volatile oils, like oil of turpentine, oil of lemon, etc. The chief illuminating ingredient of coal-gas (ethylene or olefiant gas,) the coal or rock oils, (kerosene,) together with benzine and paraffine, are so-called hydro-carbons. Sulphur is a well-known solid substance, occurring in commerce either in sticks (brimstone, roll sulphur,) or as a fine powder (flowers of sulphur), having a pale yellow color, and a peculiar odor and taste. Uncombined sulphur is comparatively rare, the com. mercial supplies being almost exclusively of volcanic origin; but in one or other form of combination, this element is universally diffused. Sulphur is combustible. It burns in the air with a pale blue flame, in oxygen gas with a beautiful purple-blue flame, yielding in both cases a suffocating and fuming gas of peculiar nauseous taste, which is called stlphurotus acid. Exp. 15.-Heat a bit of sulphur as large as a grain of wheat on a slip of iron or glass, in the flame of a spirit lamp, for observing its fusion, combustion, and the development of sulphurous acid. Further, scoop out a little hollow in a piece of chalkf twist a wire around the latter to serve for a handle, as in fig. 3; heat the chalk with a fragment of sulphur upon it until the latter ignites, and bring it into a bottle of oxygen gas. The purple flame is shortly obscured by the opaque white fume of the sulphurous acids Sulphur forms with oxygen another compound, which, in combination with water, constitutes common su7phuric acid, or oil of vitriol This is developed to a slight extent by the action of air on flowers of sulphur, but is prepared on a large scale for commerce by a complicated process. Sulphur unites with most of the metals, yielding coin. pounds known as sulphides or sulphurets. These exist in nature in large quantities, especially the sulphides of iron, copper, and lead, and many of them are valuable ores 42 THE VOLATILE PART OF PLANTS. Sulphides may be formed artificially by heating most of the metals with sulphur. ExP. 16.-Hieat the bowl of a tobacco pipe to a low red heat in a stove or furnace; have in readiness a thin iron wire or watch-sprin(g made ito a spiral coil; throw into the pipe-bowl some lumps of sulphur, and when these melt and boil with formation of a red vapor or gas, introduce the iron coil, previously heated to redness, into the sulphur vapor. The sulphur and iron unite; the iron, in fact, burns in the sulphur gas, giving rise to a black sulphide of iron, in the same manner as in Exp. 7 it Durned in oxygen gas and produced an oxide of iron. The sulphide of iron melts to brittle, round globules, and remains in the pipe-bowl. With hydrogen, the element we are now considering unites to form a gas that possesses in a high degree the odor of rotten eggs, which is, in fact, the chief cause of the noisomeness of this kind of putridity. This substance, commonly called sulphuretted hydrogen, also sulphydric acid, is dissolved in, and evolved abundantly from, the water of sulphur springs. It may be produced artificially by acting on some metallic sulphides with dilute sulphurio acid. E':P. 17.-Place a lump of the sulphide of iron prepared in Exp. 16 in a cup or wine-glass, add a little water, and lastly a few drops of oil of vitrioL Bubbles of sulphurettedhydrogen gas will shortly escape. In soils, sulphur occurs almost invariably in the form of sulphates, compounds of sulphuric acid with metals, a class of bodies to be hereafter noticed. In plants, sulphur is always present, though usually in small quantity. The turnip, the onion, mustard, horseradish, and assafcetida, owe their peculiar flavors to volatile oils in which sulphur is an ingredient. Albumin, gluten and casein,-vegetable principles never absent from plant or animal,-possess also a small content of sulphur. In hair and horn it occurs to the amount of 3 to 5 per cent. When organic matters are burned with full access of air, their sulphur is oxidized and remains in the ash as sulphuric acid, or escapes into the air as sulphurous acid. Phosphorus is an element which has such intense af 43 HOW CROPE GROW. finities for oxygen that it never occurs naturally in the free state, and when prepared by art, is usually obliged to be kept immersed in water to prevent its oxidizing, or even taking fire. It is known to the chemist in the solid state in two distinct forms. In the more commonly occurring form, it is colorless or yellow, translucent, wax-like in appearance; is intensely poisonous, inflames by moderate friction, and is luminous in the dark, hence its name, derived from two Greek words signifying light-bearer. The other form is brick red, opaque, far less inflammable, and destitute of poisonous properties. Phosphorus is extensively employed for the manufacture of friction matches. For this purpose yellow phosphorus is chiefly used. When exposed sufficiently long to the air, or immediately, on burning, this element unites with oxygen, forming a body of the utmost agricultural importance, viz: phosphoric acid. Exp. 18.-Burn a bit of phosphorus under a bottle as in Exp. 8, omitting the water on the plate. The snow-like cloud of phosphoric acid gathers partly on the sides of the bottle, but mostly on the plate. It attracts moisture when exposed to the air, and hisses when put into water. Dissolve a portion of it in water, and observe that the solution is acid to the taste. In nature phosphorus is usually found in the form of phosphates, which are compounds of metals with phosphoric acid. In plants and animals, it exists for the most part as phosphates of lime, magnesia, potash, and soda. The bones of animals contain a considerable proportion (10 per cent) of phosphorus mainly in the form of phosphate of lime. It is from them that the phosphorus employed for matches is largely procured. Exp. 19.-Burn a piece of bone in a fire until it becomes white, or nearly so. The bone loses about half its weight. What remains is bone-earth or bone-ash, and of this 90 per cent is phosphate of lime. Phosphates are readily formed by bringing together solutions of various metals with solution of phosphoric acid. ExP. 20.-Pour into each of two wine or test glasses a small quantity 44 THE VOLATILE PART OF PLAN'l.o of the solution of phosphoric acid obtained in Exp. 18. To one, add some lime-water (see note p. 36) until a white cloud orprecipitate is perceived. This is a phosphate of lime. Into the other portion, drop solution of alum. A translucent cloud of phosphate of alumina is immediately produced. In soils and rocks, phosphorus exists in the state of such phosphates of lime, alumina, and iron. In the organic world the chemist has as yet detected phosphorus in other states of combination in but a few instances. In the brain and nerves, and in the yolk of eggs, an oil containing phosphorus has been known for some years, and recently similar phosphorized oils have been found in the pea, in maize, and other grains. We have thus briefly noticed the more important characters of those six bodies which constitute that part of plants, and. of animals also, which is volatile or destructible at high temperatures, viz.: carbon, hydrogen, oxygen, nitrogen, sulphur, and phosphorus. Out of these substances chiefly, which are often termed the organic elements of vegetation, are compounded all the numberless products of life to be met with, either in the vegetable or animal world. ULTIMATE COMPOSITION OF VEGETABLE MATTER. To convey an idea of the relative proportions in which these six elements exist in plants, a statement of the ultimate or elementary percentage composition of several kinds of vegetable matter is here subjoined. Tubers of Grain of Hay of Red Potato. Peas. Clover. 44.0 46.5 47.4 5.8 6.2 5.0 K 44.7 40.0 37.8 6 1.5 4.2 2.1 4.0 3.1 7.7 Grain of Wheat. Carbon................. 46.1 Hydrogen.............. 5.8 Oxygen.............4.... 43.4 Nitrogen................ 2.3 Ash, including sulphur 24 and phosphorus i 100.0 i oo00.0 100.0 0.08 0.21 0.18 0.34 0.34 0.20 100.0 Sulphur................. 0.12 Phosphorus............. 0. 3 0 45 Straw of Theat. 48.4 5.3 38.9 0.4 7.0 100.0 0.14 0.80 HOW CROPS GROW. Our attention may now be directed to the study of each compounds of these elements as constitute the basis of plants in general; since a knowledge of them will prepare us to consider the remaining elements with a greater degree of interest. Previous to this, however, we must, first of all, gain a clear idea of that force or energy, in virtue of whose action, chiefly, these elements are held in, or separated from their combinations. ~ 3. CHEMICAL AFFINITY. Chemical attraction or affinity is the force which unites or combines two or more substances of unlike character, to a new body different from its ingredients. CAemical combination differs essentially from mere mixture. Thus we may mix together in a vessel the two gases oxygen and hydrogen, and they will remain uncombined for an indefinite time, occupying their original volume; but if a flame be brought into the mixture they instantly unite with a loud explosion, and in place of the light and bulky gases, we find a few drops of water, which is a liquid at ordinary temperatures, and in winter weather becomes solid, which does not sustain combustion like oxygen, nor itself burn as does hydrogen; but is a substance having its own peculiar properties, differing from those of all other bodies with which we are acquainted. In the atmosphere we have oxygen and nitrogen in a state of mere mixture, each of these gases exhibiting its own characteristic properties. When brought into chemical combination, they are capable of yielding a series of no less than five distinct compounds, one of which is the so-called laughing gas, while the others form suffocating and corrosive vapors that are totally irrespirable. 46 THE VOLATILE PART OF PLANTS. Chemical decomposition.-Water, thus composed or put together by the exercise of affinity, is easily decomposed or taken to pieces, so to speak, by forces that oppose affinity-e. g., heat and electricity-or by the greater affinity of some other body-e. g., sodium-as already illustrated in the preparation of hydrogen, Exp. 11. Definite proportions.-A further distinction between chemical union and mere mixture is, that, while two or more bodies may, in general, be mixed in all proportions, bodies combine chemically in comparatively few proportions, which are fixed and invariable. Oxygen and hydrogen, e.g., are found united in nature, principally in the form of water; and water, if pure, is always composed of exactly one-ninth hydrogen and eight-ninths oxygen by weight, or, since oxygen is sixteen times heavier than hydrogen, bulk for bulk, of one volume or measure of oxygen to two volumes of hydrogen. Atomic Weight of Elements.-On the hypothesis that chemical union takes place between atoms or indivisible particles of the elements, the numbers expressing the proportions by weight* in which they combine, are appropriately termed atomic weights. These numbers are only relative, and since hydrogen is the element which unites in the smallest proportion by weight, it is assumed as the standard. From the results of a great number of the most exact experiments, chemists have generally agreed upon the atomic weights given in the subjoined table for -the elements already mentioned or.described. Symbols.-For convenience in representing chemical changes, the first letter, (or letters,) of the Latin name of the element is employed instead of the name itself, and is termed its symbol. * Unless otherwise stated, parts or proportions by weight are always to be anderstood. 47 HOW CROPS GROW. TABLE OF ATOMIC WEIGHTS AND SYMBOLS OF ELEMENT* Element. At. wt. Symbol. Hydrogen 1 H Carbon 12 C Oxygen 16 O Nitrogen 14 N Sulphur 32 S Phosphorus 31 P Chlorine 35.5 C1 Mercury 200 Hg (Hydrargyrum) Potassium 39 K (Kalium) Sodium 23 Na (Natrium) Calcium 40 Ca Iron 56 Fe (Ferrum) Multiple Proportions.-When two or more bodies unite in several proportions, their quantities, when not expressed by the atomic weights, are twice, thrice, four, or more times, these weights; they are multiples of the atomic weights by some simple number. Thus, carbon and oxygen form two commonly occurring compounds, viz., carbonic oxide, consisting of one atom of each ingredient, and carbonic acid which contains to one atom, or 12 parts by weight, of carbon, two atoms, or 32 parts by weight, of oxygen. Molecular Weights of Compounds.-While elements unite by indivisible atoms, to form compounds, the compounds themselves combine with each other, or exist as molecules,t or aggregations of atoms. It has indeed been customary to speak of atoms of a compound body, but this is'an absurdity, for the smallest particles of compounds admit of separation into their elements. Thp term molecule implies capacity for division just as atom excludes that idea. * Latterly, chemists are mostly inclined to receive as the true atomic weights double the numbers that have been commonly employed, hy(lrogen, chlorine and a few others excepted. t Latin diminutive, signifying a litte mass. 48 THE VOLATILE PART OF PLANTS. The molecular weight of a compound is the sum of the weights of the atoms that compose it. For example, water being composed of 1 atom, or 16 parts by weight, of oxygen, and 2 atoms, or 2 parts by weight, of hydrogen, has the molecular weight of 18. The following scheme illustrates the molecular comtposition of a somewhat complex compound, one of the carbonates of ammonia. Ammonia gas results from the anion of an atom of nitrogen with three atoms of hydrogemn. One molecule of ammonia gas unites with a molecule of carbonim acid gas and a molecule of water, to produce a molecule of carbonate of ammonia. f Ammonia _ Hydrogen, 3 ats. =1- 7 Parts Carbonate I mo' Nitrogocn, 1 - 14 -17 parts of 1 mol. Crbonic acid, Carbon, 12 part Ammonia l 1 mol.- Oxy.zen, 2 32 parts7 parts Water, lHydrogen, 2 2' =18 Ilmol. lOxygeii, 1 16 Notation of Compounds.-For the purpose of expressing easily and concisely the composition of compounds, and the chemical changes they undergo, chemists have agreed to make the symbol of an element signify one atom of that element. Thus H implies not only the light, combustible gas hydrogen, but one part of it by weight as compared with other elements, and S suggests, in addition to the idea of the body sulphur, the idea of 32 parts of it by weight. Through this association of the atomic weight with the symbol, the composition of compounds is expressed in the simplest manner by writing the symbols of its elements one after the other, thus: carbonic oxide is represented by C 0, oxide of mercury by Hg 0, and sulphide of iron by Fe S. C 0 conveys to the chemist not only the fact of the existence of carbonic oxide, but also instructs him that its molecule contains an atom each of carbon and of oxygen, and from his knowledge of the atomic weights he gathers the proportions by weight of the carbon and oxygen in it. 3 49 IHOW CROPS GROW. When a compomund contains more than one atom of aai element, this is shown by appending a small figure to the symbol of the latter. For example: water consists of two atoms of hydrogen united to one of oxygen, the symbol of water is then H2 0. In like manner the symbol of carbonic acid is C 0O. When it is wished to indicate that more than one mole. cule of a compound exists in combination or is concerned in a chemical change, this is done by prefixing a large figure to the symbol of the compound. For instance, two molecules of water are expressed by 2 H2 O. The symbol of a compound is usually termed aformula. Subjoined is a table of the formulas of some of the compounds that have been already described or employed. FORMULAS OF COMPOUNDS. 2ame. Formula. Molecular weight. Water HI2 0 18 Sulphydric acid v H12 S 34 Sulphide of iron Fe S 88 Oxide of Mercury Hg O 216 Carbonic acid (anhydrous) C o, 44 Chloride of calcium Ca C12 111 Sulphurous acid (anhydrous) S O, 64 Sulphuric acid S 0s 80 Phosphoric acid P. 0, 142 Empirical and Rational Formulas.-It is obvious that many different formulas can be made for a body of complex character. Thus, the carbonate of ammonia, whose composition has already been stated, (p. 49,) and which contains 1 atom of Nitrogen, 1 " " Carbon, 3 atoms" Oxygen, and 5 " " Hydrogen, may be most compactly expressed by tile symbol N C 0, H,. 50 THE VOLATILE PART OF PLANTS. Such a formula merely informs us what elements and how many atoms of each element enter into the composition of the substance. It is an emnpirical formula, being the simplest expression of the facts obtained by analysis of the substance. Rational formulas, on the other hand, are intended to convey some notion as to the constitution, formation, or modes of decomposition of the body. For example, the fact that carbonate of ammonia results from the union of one molecule each of carbonic acid, water, and ammonia, is expressed by the formula N H3, Ht 0, C 0O. A substance may have as many rational formulas as there are rational modes of viewing its constitution. Equations of Formulas serve to explain the results of chemical reactions and changes. Thus the breaking up by heat of chlorate of potash into chloride of potassium and oxygen, is expressed by the followmig statement. Chlorate of potash. Chloride of potassium. Oxygein. K C1 -= K C1 + 03 The sign of equality, =, shows that what is written before it supplies, and is resolved into what follows it. The sign + indicates and distinguishes separate compounds. The employment of this kind of short-hand for exhibiting chemical changes will find frequent illustration as we proceed with our subject. Modes of Stating Composition of Chemical Compounds. -These are two, viz., atomic or molecular statements and centesimal statements, or proportions in one hundred parts, (per cent, p. c. or ~.) These modes of expressing composition are very useful for comparing together different compounds of the same elements, and, while usually the atomic statement answers for substances which are comparatively simple in their composition, the statement per cent is more useful for complex bodies. The composition 51 HOW CROPS GROW. of the two compounds of carbon with oxygen is given e low according to both methods. Atomic. Per cent. Atomic. Per cent. Carbon, (C,) 12 42.86 (C) 12 27.27 Oxygen, (0,) 16 57.14 (02) 32 72.73 Carbonic oxide, (C O,) 28 100.00 Carbonic acid, (C 02,) 44 100.00 The conversion of one of these statements into the other is a case of simple rule of three, which is illustrated in the following calculation of the centesimal composition of water from its atomic formula. Water, H2 0, has the molecular weight 18, i. e., it consists of two atoms of hydrogen, or two parts, and one atom of oxygen, or sixteen parts by weight. The arithmetical proportions subjoined serve for the calculation, viz.: H2 0 Water H lI(ydro,'cn 18: 100:: 2: per cent sought ( 11.11+) H2 0 Water 0 Oxygen 18: 100:: 16: per cent sought ( 88.88+) By multiplying together the second and third terms of these proportions, and dividing by the first, we obtain the required per cent, viz., of hydrogen, 11.11; and of oxygen, 88.88. The reader must bear well in mind that chemical affinity manifests itself with very different degrees of intensity between different bodies, and is variously modified, excited, or annulled, by other natural agencies and forces. ~ 4. VEGETABLE ORGANIC COMPOUNDS OR PROXIMATE ELEMENTS. We are now prepared to enter upon the study of the organic compounds, which constitute the vegetable structure, and which are produced from the elements carbon, oxygen, hydrogen, nitrogen, sulphur, and phosphorus, by the united agency of chemical and vital forces. The number of distinct substances found in plants isb practically unlimited. There are already well known to ohemists hundreds of oils, acids, bitter principles, resins, coloring matters, etc. Almost every plant contains some organic body 62 THE VOLATILE PART OF PLANrS. peculiar to itself, and usually the same plant in its different parts reveals to the senses of taste and smell the presence of several individual substances. In tea and coffee occurs an intensely bitter" active principle," thein. From tobacco an oily liquid of eminently narcotic and poisonous properties, nicotin, can be extracted. In the orange are found no less than three oils; one in the leaves, one in the flow. ers, and a third in the rind of the fruit. Notwithstanding the great number of bodies thus occuring in the vegetable kingdom, it is a few which form the bulk of all plants, and especially ofthose which have an agricultural importance as sources of food to man and animals. These substances, into which any plant may be resolved by simple, mostly mechanical means, are conveniently termed proximate elements, and we shall notice them in some detail under six principal groups, viz: 1. WATER. 2. The CELLULOSE GROUP OR AMyLOIDs-Cellulose, (Wood,) Starch, the Sugars and Gums. 3. The PECTOSE GROuP-the Pulp and Jellies of Fruits and certain Roots. 4. The VEGETABLE AcIDs. 5. The FATS and OILs. 6. The ALBUMINOID or PROTEIN BODIES. 1. Water, H2 0, as already stated, is the most abundant ingredient of plants. It is itself a compound of oxygen and hydrogen, having the following centesimal composition: Oxygen, 88.88 Hydrogen, 11.11 100.00 It exists in all parts of the plant, is the immediate cause of the succulence of the tender parts, and is essential to the life of the vegetable organs. In the following table are given the percentages of water in some of the more common agricultural products in thefresh state, but the pro. ro 3 H OW CROPS GROW., portions are not quite constant, even in the same part of different specimens of any given plant. WATER (per cent) IN FRESfl PLA.NTS. Meadow grass......................................72 Red clover..........................................79 Maize, as used for fodder............................81 Cabbage............................................90 Potato tubers.......................................75 Sugar beets.........................................82 Carrots.............................................85 Turnips.............................................91 Pine wood.........................................40 In living plants, water is usually perceptible to the eye or feel, as sap. But it is not only fresh plants thrat contain water. When grass is made into hay, the water is by no means all dried out, but a considerable proportion remains in the pores, which is not recognizable by the senses. So, too, seasoned wood, flour, and starch, when seemingly dry, contain a quantity of invisible water, which can be removed by heat. Exp. 21.-Into a wide glass tube, like that shown in fig. 2, place a spoonful of saw-dust, or starch, or a little hay. Warm over a lamp, but very slowly and cautiously, so as not to burn or blacken the substance. Water will be expelled from the organic matter, andl will collect on the cold part of the tube. It is thus obvious that vegetable substances may contain water in two diferent conditions. Red clover, for example, when growing or freshly cut, contains about 79 per cent of water. When the clover is dried, as for making ll 11 E hay, the greater share of this water escapes, so that the air-dry plant contains but about 17 per cent. On subjecting the Fig. 9. air-dry clover to a temperature of 212~ Fig 9 for some hours, the water is completely expelled, and the substance becomes really dry. To drive off all water from vegetable matters, the chemist usually employs a water-bath, fig. 9, consisting of a vessel of tin or copper plate, with double walls, between which is a space that may be nearly filled with water. The substance to be dried is placed in the interior chamber, 54 THE VOLATILE PART OF PLANTS. the door is closed, and the water is brought to boil by the heat of a lamp or stove. The precise quantity of water belonging to, or contained in, a substance, is ascertained by first weighing the substance, then drying it until its weight is constant. The loss is water. In the subjoined table are given the average quantities, per- cent, of water existing in various vegetable products when air-driy. WATER IN AIR-DRY PLANTS. Meadow grass, (hay,)...............................15 Red clover hay...................................17 Pine wood....................................... 20 Straw and chaff of wheat, -ryc, etc....................15 Bean straw....................................... 18 Wheat, (rye, oat,) kernel.......................... 14 Maize kernel........................................ 12 That portion of the water which the fresh plant loses by mere exposure to the air is chiefly the water of its juices or sap, and is manifest to the sight and feel as a liquid, in crushing the fresh plant; it is, properly speaking, thefree water of vegetation. The water which remains in the airdry plant is imperceptible to the senses while in the plant, -can only be discovered on expelling it by heat or otherwise,-and may be designated as the hygroscopic water of vegetation. The amount of water contained in either fresh or airdry vegetable matter is constantly fluctuating with the temperature and the dryness of the atmosphere. 2. THE CELLULOSE GROUP, OR THE AMYLOIDS. This group comprises Cellulose, Starch, Inulin, D)extri?, Gum, Cane sugar, Friit sugar, and Grape sutgar. These bodies, especially cellulose and starch, form by far the larger share-perhaps seven-eighths-of all the dry matter of vegetation, and most of them are distributed throughout all parts of plants. Cellulose, C,, H20 01o.-Every agricultural plant is an aggregate of microscopic cells, i. e., is made up of minute sacks or closed tubes, adhering to each other. 55 HOW CROPS GROW. Fig. 10 represents an extremely thin slice from the stem of a cabbage, magnified 230 diameters. The united walls of two cells are seen in section at a, while at b an empty space is noticed. Fig. 10. .4 The outer coating, or wall, of the cell is cellulose. This substance is accordingly the skeleton or framework of the plant, and the material that gives toug(h ness and solidity to its parts. Next to water it is the most abundant body in the vegetable world. All plants and all parts of all plants contain cellulose, but it is relatively most abundant in their stems and leaves. In b seeds it forms a large portion of the husk, shell, or other outer coating, but in the interior of the seed it exists in small \ quantity. The fibers of cotton, (Fig. 11, a,) hemp, and flax, (Fig. 11, b,) and white cloth and unsized paper made from these materials, are nearly pure cellulose. The fibers of cotton, hemp, and flax, are simply F. 11 long and thick-walled cells, the appearance of which, when highly magnified, is shown in'fig. 11, where a represents the thinner, more soft, and collapsed cotton fiber, and b the thicker and more durable fiber of linen. 56 THE VOLATILE PART OF PLANTS. Wood, or woody fiber, consists of long and slender cells of various forms and dimensions, see p. 271,) which are delicate when young, (in the sap wood,) but as they become older fill up interiorly by the deposition of repeated layers of cellulose, which is intergrown with a substance, (or substances,) called lignin.* The hard shells of nuts and stone fiuits contain a basis of cellulose, which is impregnated with ligneous matter. When quite pure, cellulose is a white, often silky or spongy, and translucent body, its appearance varying somewhat according to the source whence it is obtained. In the air-dry state, it usually contains about 100 l0 of hygroscopic water. It has, in common with animal membranes, the character of swelling up when immersed in water, from imbibing this liquid; on drying again, it shrinks in bulk. It is tough and elastic. Cellulose differs remarkably from the other bodies of this group, in the fact of its slight solubility in dilute acids and alkalies. It is likewise insoluble in water, alcohol, ether, the oils, and in most ordinary solvents. It is hence prepared in a state of purity by acting upon vegetable matters containing it with successive solvents, until all other matters are removed. The "skeletonized" leaves, fruit vessels, etc., which compose those beautiful objects called phantom bouquets, are commonly made by dissolving away the softer portions of fresh succulent plants by a hot solu * According to F. Schulze, lignin impregnates, (not simply incrusts,) the cell-wall, it is soluble in hot alkaline solutions, and is readily oxidized by nitric acid. Schulze ascribes to it the composition Carbon............................ 55.3 Hydrogen.......................... 5.8 Oxygen............................38.9 100.0 This is, however, simply the inferred composition of what is left after the cellulose, etc., have been removed. Lignin cannot be separated in the pure state, and has never been analyzed. What is thus designated is probably a mixtare of several distinct substances. Lignin appears to be indigestible by herbivorous animals, (Grouven, V. of. Mreter.) 3* 57 HOW CROPS GROW. tion of caustic soda, and afterwards whitening the skeleton of fibers that remains by means of chloride of lime, (bleaching powder.) They are almost pure cellulose. Slfletons may also be prepared by steeping vegetable matters in a mixture of chlorate of potash and dilute nitric acid for a number of days. Exr. 22.-To 500 cubic centimeters,* (or one pint,) of nitric acid of density 1.1, add 30 grams, (or one ounce,) of pulverized chlorate of pot ash, and dissolve the latter by agitation. Suspend in this mixture a number of leaves, etc.,t and let them remain undisturbed, at a temperature not above 65~ F., until they are perfectly whitened, which may require from 10 to 20 days. The preparations of leaves should be floated out from the solutions on slips of paper, washed copiously in clear water, and dried under pressure between folds of unsized paper. The fibers of the whiter and softer kinds of wood are now much employed in the fabrication of paper. For this purpose the wood is rasped to a coarse powder by machinery, then freed from lignin, starch, etc., by ahot solution of soda, and finally bleached with chloride of lime. The husks of maize have been successfully employed in Austria, both for making paper and an inferior cordage. Though cellulose is insoluble in, or but slightly affected by dilute acids and alkalies, it is dissolved or altered by' these agents, when they are concentrated or hot. The result of the action of strong acids and alkalies is very various, according to their kind and the degree of strength in which they are employed. The strongest nitric acid transforms cellulose into nitrocellulose, (pyrox!line, gun cotton,) a body which burns explosively, and has been employed as a substitute for gunpowder. Sulplhuric acid of a certain strength, by short contact with cellulose, converts it a tough, translucent substance which strongly resembles bladder or similar animal membranes. Paper, thus treated, becomes the vegetable parchment of commerce. * On subsequent pages we shall make frequent use of some of the French dec. imal weights and measures, for the reasons that they are much more convenient than the English ones, and are now almost exclusively employed in all scientific treatises and investigations. For small weights, the gram, abbreviated gm., (equal to 151A grains, nearly), is the customary unit. The unit of measure by vol. ume is the cuUc centtmeer, abbreviated c. c., (30 c. c. equal one fluid ounce nearly). Gram weights and glass measures graduated into lbic centimeters are furnished by all dealers in chemical apparatus. t Full-grown but not old leaves of the elm, maple, and maize, heads of unripe grain, slices of he stem and joints of maize, etc., may be employed to furnish skeletons that will prove valuable in the study of the structure of these organs. 58 THE VOLATILE PART OF PLANTS. ExP. 23.-To prepare parchment paper, fill a large cylindrical test tube first to the depth of an inch or so with water, then pour in three times this bulk of oil of vitriol, and mix. When the liquid is perfectly cool, immerse into it a strip of unsized paper, and let it remain for about 15 seconds; then remove, and rinse it copiously in water. Lastly, soak for some minutes in water, to which a little ammonia is added, and wash again with pure water. These washings are for the purpose of removing the acid. The success of this experiment depends upon the proper strength of the acid, and the time of immersion. If need be, repeat, varying these conditions slightly, until the result is obtained. Prolonged contact with strong sulphuric acid converts cellulose into dextrin, and finally into sugar, (see p. 75.) Other intermediate products are, however, formed, whose nature is little understood; but the properties of one of them is employed as a test for cellulose. Exr. 24.-Spread a slip of unsized paper upon a china plate, and pour upon it a few drops of the diluted sulphuric acid of Exp. 23. After some time the paper is seen to swell up and partly dissolve. Now flow it with a weak solution of iodine,* when these dissolved portions will assume a fine and intense blue color. This deportment is characteristic of cellulose, and may be employed for its recognition under the microscope. If the experiment be repeated, using a larger proportion of acid, and allowing the action to continue for a considerably longer time, the substance producing the blue color is itself destroyed or converted into sugar, and addition of iodine has no effect. t Boiling for some hours with dilute sulphuric acid also transforms cellulose into sugar, and, under certain eircumstances, chlorhydric acid and alkalies have the same effect upon it. The denser and more impure forms of cellulose, as they occur in wood and straw, are slowly acted upon by chemical agents, and are not easily digestible by most animals; but the cellulose of young and succulent stems, leaves, and fruits, is digestible to a large extent, especially in the stomachs of animals which naturally feed on herbage, ani therefore cellulose ranks among the nutritive substances. * Dissolve a fragment of iodine as large as a wheat kernel in 20 c. c. of alcohol, add 100 c. c. of water to the solution, and preserve in a well stoppered bottle. t According to Grouven, cellulose prepared from rye straw, (and impure?) requires several hours' action of sulphuric acid before it will strike a blue color with iodine, (2ter Salzmiinder Bercht, p. 467.) 59 HOW CROPS GROW. Chemical composition of cellulose.-This body is a com pound of the three elements, carbon, oxygen, and hydrogen. Analyses of it, as prepared from a multitude of sources, demonstrate that its composition is expressed by the formula, C12 H20 O0, In 100 parts it contains Carbon, 44.44 Hydrogen, 6.17 Oxygen, 49.39 100.00 Modes of estinatii,g cellulose.-In statements of the composition of plants, the terms fiber, woodyfiber, and crudee cellhlose, are often met with. These are applied to more or less impure cellulose, which is obtained as a residue after removing other matters, as far as possible, by alternate treatment with dilute acids and alkalies, but without acting to any great extent on the cellulose itself. The methods formerly employed, and those by which most of our analyses have been made, are confessedly imperfect. If the solvents are too concentrated, or the temperature at which they act is too high, cellulose itself is dissolved; while with toe dilute reagents a portion of other matters remains unattacked. The method adopted by Henneberg, (Versuchs-Stationen, VI, 497,) with quite good results, is as follows: 3 grams of the finely divided substance are boiled for half an hour with 200 cubic centimeters of dilute sulphuric acid, (containing 1/1 per cent of oil of vitriol,) and after the substance has settled, the acid liquid is poured off. The residue is boiled again for half an hour with 200 c. c. of water, and this operation is repeated a second time. The residual substance is now boiled half an hour with 200 c. c. of dilute potash lye, (containing l/4 per cent of dry caustic potash,) and after removing the alkaline liquid, it is boiled twice with water as before. What remains is brought upon a filter, and washed with water, then with alcohol, and, lastly, with ether, as long as these solvents take up anything. This crude cellulose contains ash ard nitrogen, for which corrections must be made. The nitrogen is assumed to belong to some albuminoid, and from its quantity the amount of th, latter is calculated, (see p. 108.) Even with these corrections, the quantity of cellulose is not obtained with entire accuracy, as is usually indicated by its appearance and its composition. While, according to V. Iofmeister, the crude cellulose thus prepared from the pea is perfectly white, that from wheat bran is brown, and that from rape-cake is almost black in color. Grouven gives the following analyses of two samples of crude cellulose obtained by a method essentially the same as we have described. (se Saltzufinde Bericht, p. 456.) 60 THE VOLATILE PART OF PLANTS. tye-straw,fiber. IVater...........8.65 Ash.............2.05 N...............0.15 C..............42.47 H...............6.04 0...............40.64 100.00 On deducting water and ash, and making proper correction for the nitrogen, the above samples, together with one of wheat-straw fiber, analyzed by Henneberg, exhibit the following composition, compared with pure cellulose. W/eat-stra vfiber. 45.4 6.3 48.3 100.0 Rye-straw fiber. C............47.5 H............ 6.8 0............45.7 100.0 Franz Schulze, of Rostock, proposed in 1857 another method for estimating cellulose, which has recently, (1866,) been shown to be more correct than the one already described. Kuhn, Aronstein, and H. Schulze, (tenneberg's Journal fuir Landwirthschaft, 1866, pp. 289 to 297,) have applied this method in the following manner: One part of the dry pulverized substance, (2 to 4 grams,) which has been previously extracted with water, alcohol, and ether, is placed in a glass-stoppered bottle, with 0.8 part of chlorate of potash and 12 parts of nitric acid of specific gravity 1.10, and digested at a temperature not exceeding 65' F. for 14 days. At the expiration of this time, the contents of the bottle are mixed with some water, brought upon a filter, and washed, firstly, with cold and afterwards, with hot water. When all the acid and soluble matters have been washed out, the contents of the filter are emptied into a beaker, and heated to 165~ F. for about 45 minutes with weak ammonia, (1 part commercial ammonia to 50 parts of water); the substance is then brought upon a weighed filter, and washed, first, with dilute ammonia, as long as this passes off colored, then with cold and hot water, then with alcohol, and, finally, with ether. The substance remaining contains a small quantity of ash and nitrogen, for which corrections must be made. The fiber is, however, purer than that procured by the other method, and a somewhat larger quantity, (12 to 1S per cent,) is obtained. The results appear to vary but about one per cent from the truth. The avcrag,e proportions of cellulose found in various vegetable matters in the usual or air-dry state, are as follows: 61 I Li?ienftber. 5.40 1.14 o.26 38.36 5.89 48.95 100.00 Lineit fiber. 41.0 6.4 52.6 100.0 Pa)-e cellulose. 44.4 6.2 49.4 100.0 HOW CROPS GROW. AMOUNT OF CELLULOSE IN PLANTS. er oent. Red clover plant in flower...10 " " hay...................34 Timothy ".............23 Maize cobs..................38 Oat straw..................40 Wheat"..................48 Rye ".................. 54 Starch, 12 -2 O010.-TThe cells of the seeds of wheat, corn, and all other grains, and the tubers of the potato, contain this familiar body in great abundance. It occurs also in the wood of all forest trees, especially in autumn and winter. It accumulates in extraordinary quantity in the pith of some plants, as in the Sago-palm, (Metroxylon Rumphii,) of the Malay Islands, a single tree of which may yield 800 lbs. Starch occurs in greater or less quantity in every plant that has been examined for it. The preparation of starch from the potato is very simple. The potato contains, on the average, 76 per cent water, 20 per cent starch, and 1 per cent of cellulose, while the remaining 3 per cent consists mostly of matters which are easily soluble in water. By grating, the potatoes are reduced to a pulp; the cells are thus broken and the starchgrains set at liberty. The pulp is then agitated on a fine sieve, in a stream of water. The washings run off milky, fiom suspended starch, while the cellulose is retained by the sieve. The milky fluid is allowed to rest in vats until the starch is deposited. It is then poured off, and the starch is collected and dried. Wheat-starch is commonly made by allowing wheaten flour mixed with water to ferment for several weeks. By this process the gluten, etc., are converted into soluble matters, which are removed by washing, from the unaltered starch. Starch is now largely manufactured from maize. A 62 Per cent. Potato tiiber............ 1.1 Wheat kernel........... 3.0 Wheat meal............. 0.7 Ma.ize kei-nel............ 5.5 Barley 11 8.0 Oat t............ 10.3 Buckwheat kernel....... 15.0 THE VOLATILE PART OF PLANTS. dilute solution of caustic soda is used to dissolve the albuminoids, see p. 95. The starch and bran remaining, are separated by diffusing both in water, when the bran rapidly settles, and the water being run off at the proper time, deposits the pure starch, corn-starch of commerce, also known as maizena. Starch is prepared by similar methods from rice, horsechestnuts, and various other plants. Arrow-root is starch obtained by grating and washing the root-sprouts of Maranta Indica, and M. arundinacea, plants native to the West Indies. Exp. 25.-Reduce a clean potato to pulp by means of a tin grater. Tie up the pulp in a piece of not too fine muslin, and squeeze it repeatedly in a quart or more of water. The starch grains thus pass the meshes of the cloth, while the cellulose is retained. Let the liquid stand until the starch settles, pour off the water, and dry the residue. Starch, as usually seen, is a white powder which consists of minute, rounded grains, and hence has a slightly harsh feel. When observed under a powerful magnifier, these grains often present characteristic forms and dimensions. In potato-starch they are egg or kidney-shaped, and are e;e 9 6~~ ~~ 0 9. ~a %@b a~) 6 0 o O a 0 :o o *o o GQ'.Q;; 0 Fi. 12. distinctly marked with curved lines or ridges, which surround a point or eye; a, fig. 12. Wheat-starch consists of grains shaped like a thick burning-glass, or spectacle-lens, having a cavity in the centre, b. Oat-starch is made up of compound grains, which are easily crushed into smaller 63 a HOW CROPS GROW. granules, c. In maize and rice the grains are usually so densely packed in the cells as to present an angular (sixsided) outline, as in d. The starch of the bean and pea has the appearance of e. The minute starch-grains of the parsnip are represented atf, and those of the beet at g. The grains of potato-starch are among the largest, being often 1-300th of an inch in diameter; wheat-starch grains are about 1-1000th of an inch; those of rice, 1-3000th of an inch, while those of the beet-root are still smaller. Unorganized Starch exists as a jelly in several plants, according to Schleiden, (Bo'atik p. 127). Dragendorff asserts, that in the seeds of colza and mustard the starch does not occur in the form of grains, but in an unorganized state, which he considers to be the same as that noticed by Schleiden. The starch-grains are unacted upon by cold water, unless broken, (see Exp. 26,) and quickly settle from suspension in it. When starch is triturated for a long time with cold water, whereby the grains are broken, the liquid, after filtering or standing until perfectly clear, contains starch in extremely minute quantity. When starch is heated to ncar boiling with 12 to 15 times its weight of water, the grains swell and burst, or exfoliate, the water is absorbed, and the whole forms a jelly. This is the starch-paste used by the laundress for stiffening muslin. The starch is but very slightly dissolved by this treatment; see Exp. 27. On freezing, it separates almost perfectly. When starch-paste is dried, it forms a hard, horn-like mass. Tapioca and Sago are starch, which, from being heated while still moist, is partially converted into starch-paste, and, on drying, acquires a more or less translucent aspect. Tapioca is obtained from the roots of the lfanihot, a plant which is cultivated in the West Indies and South America. Cassava is a preparation of the same starch, roasted. Sago is made in the islands of the East Indian Archipelago, from the pith of palms. It is granulated by forcing the paste through metallic sieves. Both tapioca and sago are now imitated from potato starch. Test for Starch.-The chemist is enabled to recognize starch with the greatest ease and certainty by its peculiar deportment towards iodine, which, when dissolved in wa ter or alcohol and brought in contact with starch, gives it a beautiful purple or blue color. This test may be used even in microscopic observations with the utmost facility. 64 THE VOLATILE PART OF PLANTS. ExP. 26.-Shake together in a test tube, 30 c. c. of water and starch of the bulk of a kernel of maize. Add solution of iodine, drop by drop, agitating until a faint purplish color appears. Pour off half the liquid into another test tube, and add at once to it one-fourth its bulk of iodine solution. The latter portion becomes intensely blue by transmitted, or almost black by reficcted light. On standing, observe that in the first case, where starch preponderates, it settles to the bottom leaving a colorless liquid, which shows the insolubility of starch in cold water; the starch itself has a purple or red tint. In the case iodine was used in excess, the deposited starch is blue-black. ExP. 27.-Place a bit of starch as large as a grain of wheat in 30 c. c. of cold water and heat to boiling. The starch is converted into thin, translucent paste. That a portion is dissolved is shown by filtering through paper and adding to one-half of the filtrate a few drops of iodine solution, when a perfectly clear blue liquid is obtained. The delicacy of the reaction is shown by adding to 30 c. c. of water a little solution of iodine, and noting that afew drops of the solution of starch suffice to make the large mass of liquid perceptibly blue. By the prolonged action of dry heat, hot water, acids, or alkalies, starch is converted first into dextrin, and finally into sugar (glucose), as will be presently noticed. The same transformations are accomplished by the action of living yeast, and of the so-called diastase of germinating seeds; see p. 328. The saliva of man and plant-eating animals usually likewise dissolves starch at blood heat by converting it into sugar. It is much more promptly converted into sugar by the liquids of the large intestine. It is thus digested when eaten by animals. It is, in fact, one of the most important ingredients of the food of man and domestic animals. The action of saliva demonstrates that starch-grains are not homogeneous, but contain a small proportion of matter not readily soluble in this liquid. This remains as a delicate skeleton after the grains are otherwise dissolved. It is probably cellulose. The chemical composition of starch is identical with that of cellulose; see p. 60. Air-dry starch always contains a considerable amount of hygroscopic water, which usually ranges from 12 to 20 per cent. 65 HOW CROPS GROW. Next to water and cellulose, starch is the most abundant ingredient of agricultural plants. In the subjoined table are given the proportions contained in certain vegetable products, as determined by Dr. Dragendoriff. The quantities are, however, somewhat variable. Since the figures below mostly refer to air-dry substances, the proportions of hygroscopic water are also given, the quantity of which being changeable must be taken into account in making any strict comparisons. AMOUNT OF STARCH IN PLANTS. Water. Per cent. Wheat.................. 13.2 Wheat flour............. 15.8 Rye.................... 11.0 Oats.................... 11.9 Barley.................. 11.5 Timothy seed........... 12.6 Rice (hulled)............. 13.3 Peas.................... 5.0 Beans (white)............. 16.7 Clover seed............. 10.8 Flaxseed..................7.6 Mustard seed.............. 8.5 Colza seed.............. 5...8 Teltow turnips *........ dry substance Potatocs................ dry substance Starch is quantitatively estimated by various methods. 1. In case of potatoes or cereal grains, it may be determined roughly ty direct mechanical separation. For this purpose 5 to 20 grams of the 6ubstance are reduced to fine division by grating (potatoes) or by softenIng in warm water, and crushing in a mortar (grains). The pulp thus obtained is washed either upon a'fine hair-sieve or in a bag of muslin, until the water runs off clear. The starch is allowed to settle, dried, and weighed. The value of this method depends upon the care employed in the operations. The amount of starch falls out too low, because it is impossible to break open all the minute cells of the substance analyzed. 2. In many cases starch may be estimated with more precision by conversion into sugar; see p. 76. 3. Dr. Dragendorff, of the Rostock Laboratory, proceeds with starch de-*t terminations as follows: The pulverized substance, after drying out all hygroscopic moisture at 212~, is digested for 18 to 30 hours, at a temperature of 212~, in 10 to 12 times its weight of a solution of 5 to 6 parts of hydrate of potash in 94 to 95 parts of anhydrous alcohol. The digestion must take place in sealed glass tubes, or in a silver vessel which admits of closing perfectly. By this treatment the * A sweet and mealy turnip grown on light soils for table use. 66 arch. Per cent. 59.5 68.7 59.7 46.6 57.5 45.0 61.7 37.3 33.0 10.8 23.4 9.9 8.6 9.8 62.5 THE VOLATILE PART OF PLANTS. albuminoid substances, the fats, the sugar, and dextrin, are brought into such a condition that simple washing with alcohol or water suffices to remove them completely. Thie chief part of the phosphoric and silicic acids is likewise rendered soluble. The starch-grains arc not affected, neither does the cellulose undergo alteration, either qualitatively or quantitatively. In fact, this treatment serves excellently to isolate starch-grains for microscopic investigations. Besides starch and cellulose nothing resists the action of alcoholic potash save portions of cuticle, gum, and some earthy salts. When the digestion is finished, it is advisable, especially in case the substance is rich in fat, to bring the contents of the tube upon a filter while still hot, as otherwise potash-salts of the fatty acids may crystallize out. It is also well to wash immediately, first, with hot absolute alcohol, then, with cold alcohol of ordinary strength, and finally, with cold water until these several solvents remove nothing more. In the analysis of matters which contain much mucilage, as flaxseed, the washing must be completed with alcohol of 8 to 10 per cent, to prevent the swelling up of the residue. The filter should be of good ordinary (not Swedish) paper, should be washed with chlorlhydric acid and water, dried at 212~, and weighed. When the substance is completely washed, the filter and its contents are dried, first at 120~, and finally at 212~. The loss consists of albuminoids, fat, sugar, and a part of the salts of the substance, and when the last three are separately estimated, it may serve to control the estimation, by elementary analysis, of the albuminoids. The filter, with its contents, is now reduced to powder or shreds, and the whole is heated with water containing 5 per cent of chlorhydric acid until a drop of the liquid no longer reacts blue with iodine. The treatment with potash leaves the starch-grains in such a state of purity from incrusting matters, that their conversion into dextrin proceeds with great promptness, and is accomplished before the cellulose begins to be perceptibly acted upon. By weighing the residue that remains from the action of chlorhydric acid, after washing and drying, the amount of cellulose, cork, lignin, gum, and insoluble fixed matters is found. By subtracting these from the weight of the substance after exhaustion with potash, the quantity of starch is learned with great accuracy. The only error introduced by this method lies in the solution of some saline matters by the acid. The quantity is, however, so small as rarely to be appreciable. If needful, it can be taken into account by evaporating the acid solution to dryness, incinerating and weighing the residue. By warming with concentrated malt-extract at ]32~, the starch -.done is taken into solution, and no correction is needed for saline matters. If it is wished to determine the sugar produced by the transformation of the starch, a weaker acid must of course be employed. In case of mucilaginous substances, the starch must be extracted by digestion with a strong solution of chloride of sodium, with which the requisite quantity of chlorhydric acid has been mixed, and the residue should be 67 HOW CROPS GROW. washed with water to which some alcohol has been added.-lT&nneber9's Tou'nalffi.r Landwirthschaft, 1862, p. 206. Inulin, C,,2 Ito 0,10 closely resembles starch in many points, and appears to replace that body in the roots of the artichoke, elecampane, dahlia, dandelion, chicory, and other plants of the same natural family (compositce). It may be obtained in the form of minute white grains, which dissolve easily in hot water, and mostly separate again as the water cools. Unlike starch, inulin exists in a liquid form in the roots above named, and separates in grains from the clear pressed juice when this is kept some time. According to Bouchardat, the juice of the dahlia tuber, expressed in winter, becomes a semi-solid white mass in this way, after reposing some hours, from the separaAion of 8 per cent of this substance. Inulin, when pure, gives no coloration with iodine. It may be recognized in plants, where it occurs in a solution usually of the consistence of a thin oil, by soaking a slice of the plant in strong alcohol. Inulin is insoluble in this liquid, and under its influence shortly separates as a solid in the form of spherical granules, which may be identified with the aid of the microscope. When long boiled with water it is slowly but completely converted into a kind of sugar, (levulose); hot dilute acids accomplish the same transformation in a short time. It is digested by animals, and doubtless has the same value for food as starch. In chenmical composition, inulin agrees perfectly with cellulose and starch; see p. 60. Dextrin, C.12 20 O10, has been thought to occur in small quantity dissolved in the sap of all plants. According to Von Bibra's late investigations, the substance existing in bread-grains which earlier experimenters believed to be dextrin, is in reality gum. Busse, who has still more recently examined various young cereal plants and seeds, 68 THE VOLATILE PART OF PLANTS. and potato tubers, for dextrin, found it only in old potatoes and young wheat plants, and there in very small quantity. — Jahresbericht fizr Chemie, 1866, p. 664. Dextrin is easily prepared artificially by the transformation of starch, and its interest to us is chiefly due to this fact. When starch is exposed some hours to the heat of an oven, or 30 minutes to the temperature of 415~ F., the grains swell, burst open, and are gradually converted into a light-brown substance, which dissolves readily in water, forming a clear, gummy solution. This is dextrin, and thus prepared it is largely used in the arts, especially in calicoprinting, as a cheap substitute for gum arabic, and bears the name British gum. In the baking of bread it is formed from the starch of the flour, and often constitutes ten per cent of the loaf. The glazing on the crust of bread, or upon biscuits that have been steamed, is chiefly due to a coating of dextrin. Dextrin is thus an important ingredient of those kinds of food which are prepared firom the starchy grains by cooking. British gum, or commercial dextrin, appears either in translucent brown masses, or as a yellowish-white powder. On addition of cold water, the dextrin readily dissolves, leaving behind a portion of unaltered starch. When the solution is mixed with strong alcohol, the dextrin separates in white flocks, which, upon agitation, unite to translucent salvy clumps. With iodine, solution of commercial dextrin gives a fine purplish-redl color. Pure dextrin is, however, unaffected by iodine. ExP. 28.-Cautiously heat a spoonful of powdered starch in a porcelain dish, with constant stirring so that it may not burn, for the space of five minutes; it acquires a yellow, and later, a brown color. Now add thrice its bulk of water, and heat nearly to boiling. Observe that a slimy solution is formed. Pour it upon a filter; the liquid that runs through contains dextrin. To a portion, add twice its bulk of alcohol; dextrin is precipitated. To another portion, add solution of iodine; this shows the presence of dissolved but unaltered starch, which likewise re. mains solid in considerable quantities upon the filter. To a third portion 69 HOW CROPS GROW. of the filtrate add one drop of strong sulphuric acid, and boil a few minutes. Test with iodine, which will now prove that all the starch is transformed. Not only heat, but likewise acids and ferments produce dextrin from starch, and also from cellulose. In the sprouting of seeds it is formed from starch, and hence is an ingredient of malt liquors. It is often contained in the animal body. Limpricht obtained nearly a pound of dextrin from 200 lbs. of the flesh of a young horse.-Ann. Ch. Ph., 133, p. 295. The chemical composition of dextrin is the same as that of cellulose, starch, and inulin. The Gums.-A number of bodies exist in the vegetable kingdom, which, from the similarity of their properties, have received the common designation of Gums. The best known are Gum Arabic, or Arabi2; the gum of the Cherry and Plum, or Cerasin; Gum Tragacanth and Bassora Gum, or Bassorin; and the Vegetable Mucilage of various roots, viz., of mallow and comfrey; and of certain seeds, as those of flax and quince. Arabin.-Gum Arabic or Arabin exudes firom the stems of various species of acacia that grow in the tropical countries of the East, especially in Arabia and Egypt. It occurs in tear-like, transparent, and, in its purest form, colorless masses. These dissolve easily in their own weight of water, forming a viscid liquid, or mucilage, which is employed for causing adhesion between surfaces of paper, and for thickening colors in calico-printing. Gum Arabic, when burned, leaves about 3 per cent of ash, chiefly carbonates of lime and potash; it is, in fact, a compound of lime and potash with Arabic acid. Arabic Acid is obtained pure by mixing a strong solution of gunm Arabic with chlorhydric acid, and adding alcohol. It is thus precipitated as a milk-white mass, which, when dried at 212', becomes transparent, and has the composition C12 H22 O.l 70 THE VOLATILE PART OF PLANTS. In 100 parts, Arabic acid contains: Carbon 42.12 Hydrogen 6.41 Oxygen 51.47 100.00 By exposure to a temperature of 250~, Arabic acid loses one molecule of water, and becomes insoluble in water, being transformed into Meta)abic Acid, (Freony's Acide mnetagummique). Cerasin.-The gum which frequently forms glassy masses on the bark of cherry, plum, apricot, peach, and almond trees, is a mixture in variable proportions of Arabin, or the arabates of lime and potash, with cerasin, or the metarabates of lime and potash. Cold water dissolves the former, while the cerasin remains undissolved, but swollen to a pasty mass or jelly. lMetarabic Acid is prepared, as above stated, by exposing Arabic acid to a temperature of 250~ F., and its composition is C12 H20 O10. It is likewise produced by putting solution of gum Arabic in contact with oil of vitriol. On the other hand, metarabic acid is converted into Arabic acid, by boiling with water and a little lime or alkali. Metarabic acid, as well as its compounds with lime, potash, etc., are insoluble in water. Bassorin, C,1 H20 010, as found in Gum Tragacanth, has much similarity to metarabic acid in its properties, being insoluble in water, but swelling up in it to a paste or jelly. Vegetable Mucilage, C12 H00 01 0, has the same composition, and near- ly the same characters as Bassfrin, and is possibly identical with it. It < <~ is an almost universal constituent b [ glU[[ g of plants. It is procured in a state of purity by soak- dC Z lug unbroken flaxseed in cold water, with frequent agitation, beating the liquid to boiling, straining, and evaporating, until addition of alcohol separates tenacious 0 O threads from it. It is then precipitated by Fi0 1. alcohol containing a little chlorhydric Fig. 13. acid, and washed by the same mixture. On drying, it forms a horny, colorless. and friable mass. Fig. 13 represents a highly magnified sec 71 HOW CROPS GROW. tion of the flaxseed. The external cells, a, contain the mucilage. When soaked in water, the mucilage swells, bursts the cells, and exudes. One or other of these kinds of gum has been found in the following plants, viz., basswood, elm, apple, grape, castor-oil bean, mangold, tea, sunflower, pepper, in various sea-weeds, and in the seeds of wheat, rye, barley, oats, maize, rice, buckwheat, and millet. In the bread-grains, Arabin, or at least a soluble gum, occurs often in considerable proportion. TABLE OF THE PROPORTIONS (per cent) OF GUM IN VARIOUS AIR-DRY PLANTS OR PARTS OF PLANTS. (According to Von Bibra, Die Getreideartei unid daes Bi-od.) Wheat kernel............................ 4.50 Wheat flour, ~uperfine................... 6.25 Spelt flour, (Triticum spelta,)............. 2.48 Wheat bran............................. 8.85 Spelt bran................................12.52 Rye kernel.........................4.10 Rye flour................................. 7.25 Rye bran.......................... 10.40 Barleyfflour.............................. 6.33 Barey bran.............................. 6.88 Oat meal................................. 3.50 Rice flour................................ 2.00 Millet flour..............................10.60 Maize meal.............................. 3.05 Buckwheat flour........................ 2.85 The gums are converted into sugar by long boiling with dilute acids. The recent experiments of Grouven show that, contrary to what has been taught hitherto, gum, (at least gum Arabic,) is digestible by domestic animals. Saccharose or Cane Sugar, C12 H22 011, so called because first and chiefly prepared from the sugar cane, is the ordinary sugar of commerce. When pure, it is a white solid, readily soluble in water, forming a color- Fig. 14. less, ropy, and intensely sweet solution. It crystallizes in rhombic prisms, fig. 14, which are usually small, as in 72 THE VOLATILE PART OF PLANTS. granulated sugar, but in the form of rcek candy may be found an inch or more in length. The crystallized sugar obtained largely friom the sugar-beet, in Europe, andcl that furnished in the United States by the sugar-maple and sorghum, when pure, are identical with cane-sugar. Saccharose also exists in the vernal juices of the walnut, birch, and other trees. It occurs in the stems of unripe maize, in the nectar of flowers, in fiesh honey, in parsnips, turnips, carrots, parsley, sweet potatoes, in the stems and roots of grasses, and in a multitude of fruits. Exp. 29.-Heat cautiously a spoonful of white sugar until it melts, (at 356' F.,) to a clear yellow liquid. On rapid cooling, it gives a transparent mass, known as barley sugar, which is employed in confectionery. At a higher heat, it turns brown, froths, emits pungent vapors, and lecomes burnt sugar, or caramel, which is used for coloring soups, ale, etc. The quantity per cent of saccharose in the juice of various plants is given ill the annexed table. It is, of course, variable, depending upon 'the variety of plant in case of cane, beet, and sorghum, as well as upon the stage of growth. SACCIIAROSE IN rLANTS. per cent. Sugar cane, average...............18 Peligot Sugar beet, "...............10 Sorghum......................... 92 Goessmann Maize, just flowered.............. 34 Ludersdorff Sugar maple, sap,average.......... 2y Liebig Red maple, " "............ 2 " When a solution of this sugar is heated with dilute acids, or when acted oi by yeast, it is converted into a mixture of equal parts of levulose, (fruit sugar,) and glucose, (grape sugar.) The composition of saccharose is the same as that of Arabic acid, and it contains in 100 parts: Carbon 42.11 Hydrogen 6.43 Oxygen 51.46 100.00 Levulose, or Fruit Sugar, (Fructose,) C2,, H,4 O,12, exists mixed with other sugars in sweet fruits, honey, and mo 4 73 IIOW CROPS GROW. lasses. Inulin is converted into this sugal by long boiling with dilute acids, or with water alone. When pure, it is a colorless, amorphous* mass. It is incapable of crystallizing or granulating, and usually exists dissolved in a small proportion of water as a syrup. Its sweetness is equal to that of saccharose. Levulose contains in 100 parts: Carbon 40.00 Hydrogen 6.67 Oxygen 53.33 100.00 Glucose or Grape Sugar, Cl, H14 O,,, naturally occurs associated with levulose in the juices of plants and in honey. Granules of glucose separate from the juice of the grape in drying, as may be seen in old "candied" raisins. Honey often granulates, or candies, on long keeping, from the crystallization of a part of its glucose. Glucose is formed from dextrin by the action of hot dilute acids, in the same way that levulose is produced from inulin. In the pure state it exists as minute, colorless crystals, and is, weight for weight, but half as sweet as the foregoing sugars. In composition it is identical with levulose. It combines chemically with water in two proportions. Mono-hy. drated glucose, (CI2 1124 012 H20,) or Anthln's hard crystallized grapesugar, which is prepared in Germany by a secret process, is dry to the feel. Bi-hydrated glucose, (C,2 H24 012 2H20O,) occurs in commerce in an impure state as a soft, sticky, crystalline mass, which becomes doughy at a slightly elevated temperature. Both these hydrates lose their crystalwater at 212'. Dissolved in water, glucose yields a syrup, which is thin, and destitute of the ropiness of cane-sugar syrup. It does not crystallize, (granulate,) so readily as cane-sugar. ExP. 30.-Mix 100 c. c. of water with 30 drops of strong sulphuric acid, and heat to vigorous boiling in a glass flask. Stir 10 grams of * Literally without shape, i.e., not crystallize. 74 THE VOLATILE PART OF PLANTS. Etarch with a little water, and pour the mixture into the ho, liqui(l, drop by drop, so as not to interrupt the boiling. The starch dissolves, and passes first into dextrin, and finally into glucose. Continue the ebullition for several hours, replacing the evaporated water fi'om time to time. To remove the sulphuric acid, add to the liquid, which may be still milky from impurities in the starch, powdered chalk, until the sour taste disappears; filter fiom the sulphate of lime, (gypsum,) that is formed, and evaporate the solution of glucose* at a gentle heat to a syrupy consistence. On long standing it may crystallize or granulate. By this method is prepared the so-called potato-sugar, or starch-sugar of commerce, which is added to grape-juice for making a stronger wine, and is also employed to adulterate cane or beet-sugar. In the sprouting and malting of grain, glucoset is likewise produced from starch. Even cellulose is convertible into glucose by the prolonged action of hot dilute acids, and saw-dust has thus been made to yield an impure syrup, suitable for the production of alcohol. In the formation of glucose from cellulose, starch, and dextrin, the latter substances take up the elements of water as represented by tile equation Starch7, &c. Wate. Glucose. C12 H20 010 + 2 H20 C12 H24 012 In this process, 90 parts of starch, &c., yield 100 parts of glucose. Tromm7er's Copper test.-A characteristic test for glucose and levulose is found in their deportment towards an alkaline solution of oxide of copper, which readily yields up oxygen to these sugars, being itself reduced to yellow or red suboxide. Exp. 31.-Prepare the copper test by dissolving together in 30 c. c. of warm water a pinch of sulphate of copper and one of tartaric acid; add to the liquid, solution of caustic potash until it feels slippery to the sklain. Place in separate test tubes a few drops of solution of cane-sugar, a similar amount of the dextrin solution, obtained in Exp. 28; of solution of glucose, from raisins, or from Exp. 30; and of molasses; add to each a little of the copper solution, and place them in a vessel of hot * If the boiling has been kept up but an hour or so, the glucose will contain dextrin, as may be ascertained by mixing a small portion of the still acid liquid with 5 times its bulk of strong alcohol, which will precipitate dextrin, but not glucose. t According to some authorities, the sugar of malt is distinct from glucose, and has been designated maltose. Probably, however, the so-called maltose is a mixture of glucose and dextrin. ,5 HOW CROPS GROW. water. Observe that the saccharose and dextrini suffer no alteration for a long time, while the glucose and molasses shortly cause the separation of suboxide of copper. Exp. 32.-Iieat to boiling a little white cane-sugar with 30 c. c. of water, and 3 drops of strong sulphuric acid, in a glass or porcelain dish, for 15 minutes, supplying the waste of water as needful, and test the liquid as in the last Exp. It will be found that this treatment transforms saccharoe into glucose, (and levnlose.) The quantitative estimation of the sugars and of starch is commonly based upon the reaction just described. For this purpose the alkaline copper solution is made of a known strength by dissolving a given weight of sulphate of copper, etc., in a given volume of water, and the glucose, or levulose, or a mixture of both, being likewise made to a known volume of solution, it is allowed to flow slowly from a graduated tube into a measured portion of warm copper solution, until the blue color is discharged. Experiment has demonstrated that one part of glucose or of levulose reduces 2.205 + parts of oxide of copper. Starch and saccharose are first converted into glucose and levulose, by heating with an acid, and then examined in the same manner. For the details required to ensure accuracy, consult Fresenius' Qlta1ttitative Analysis. As already stated, cane-sugar, by long boiling of its aqueous solution, and under the influence of hot dilute acids (Exp. 32) and yeast, loses its property of ready crystallization, and is converted into levulose and glucose. According to Dubrunfaut, two molecules of cane-sugar take up the elements of two molecules, (5.26 per cent,) of water, yielding a mixture of equal parts of levulose and glucose. This change is expressed in chemical symbols as follows: 2 (C,2 H122 02) + 2 1H20 = C,2 H24 012 + C12 H24 012 Cane-sugar. Water. Levulose. GlScose. The alterability of saccharose on heating its solutions occasions a loss of one-third to one-half of what is really contained in cane-juice, and is one reason that solid sugar is obtained firom the sorghum with such difficulty. AMolasses, sorghum syrup, and honey,usually contain all three of these sugars. In molasses, both the saccharose and glucose are hindered from crystallization by the levulose, and by saline matters derived from the cane-juice. Honey-dew, that sometimes falls in viscid drops from the leaves of the lime and other trees, is essentially a mix 76 THE VOLATILE PART OF PLANTS. ture of the three sugars with some gum. The mannas of Syria and Kurdistan are of similar composition. The older observers assumed the presence of glucose in the bread grains. Thus Vauquelin found, or thought he found, 8.5~01 of this sugar in Odessa wheat. More recently, Peligot, Mitscherlich, and Stein have denied the presence of any sugar in these grains. In his work on the Cereals and Bread, (Die Getreidearten und das Brod, 1860,) p. 163, Yon Bibra has reinvestigated this question, and found in fresh ground wheat, etc., a sugar having some of the characters of saccharose, and others of glucose and levulose. It is, therefore, a mixture. Von Bibra found in the flour of various grains the following quantities of sug,ar. PROPORTIONS OF SUGAR IN AIR-DRY FLOUR, BRAN, AND MEAL. Per cent. Wheat flour...............................2.33 Spelt flour................................1.41 Wheat bran............................ 4.30 Spelt bran...............................2.70 Rye flour..................................3.46 Rye bran..................................1.86 Barley meal...............................3.04 Barley bran...............................1.90 Oat meal..................................2.19 Rice flour.................................0.39 Millet flour...............................1.30 Maize meal................................3.71 Buckwheat meal...........................0.91 Gltcosides.-There occur in the vegetable kingdom a large number of bodies, usually bitter in taste, which contain glucose, or a similar sugar, chemically combined with other substances, or yield it on decomposition. Tannin, the bitter principle of oak and hemlock bark; salicin, from willow bark; phloridzin, from the bark of the apple-tree root, and principles contained in jalap, scamnmony, the horse chestnut, and alinond, are of this kind. The sugar may be obtained from these so-called glucosides by heating with dilute acids. 77 HOW CROPS GROW. Othe- sugars.-Other sugars or saccharoid bodies occurring in common or cultivated plants, but requiring no extended notice here, are the fol lowing: Jfannite, Cd H14 06, is abundant in the so-called manna of the apotlhecary, which exudes from the bark of several species of ash that grow in the Eastern Hemisphere, (Fr-axinus ornus and rotindifolia.) It likewise exists in the sap of our fruit trees, in edible mushrooms, and sometimes is formed in the fermentation of sugar, (viscous fermentation.) It appears in minute colorless crystals, and has a sweetish taste. Quewrcite, C6 H12 05, is the sweet principle of the acorn, from which it may be procured in colorless crystals. Pinite, C H1,2 05, exudes from wounds in the bark of a Californian and Australian pine, (Pinus Lambertiana.) Separated from the resin that usually accompanies it, it forms a white crystalline mass of a very sweet taste. Xycose, C12 1122 011, is a sugar found in ergot of rye. It may be obtained in crystals, and is very sweet. Suqar of Milk, Lactose, Cl2 H2 O1 + 11H20, is the sweet principle of the milk of animals. It is largely prepared for commerce, in Switzerland, by evaporating whey, (milk fi-om which casein and fat have been separated for making cheese.) In a state of purity, it forms transparent, colorless crystals, which crackle under the teeth, and are but slightly sweet to the taste. When dissolved to saturation in water, it forms a sweet but thin syrup. Mutual transformations of the members of the Cellulose Group.-One of the most remarkable facts in the history of this group of bodies is the facility with which its members undergo mutual conversion. Some of these changes have been already noticed, but we may appropriately review them here. a. Ti-ansformations in theplant.-The machinery of the vegetable organism has the power to transform most, ifnot all, of these bodies into every other one, and we find nearly all of them in every individual of the higher order of plants in some one or other stage of its growth. In germination, the starch which is largely contained in seeds is converted into dextrin and glucose. It thereby acquires solubility, and passes into the embryo to feed the young plant. Here it is again solidified as cellulose, starch, or other organic principle, yielding, in fact, the chief part of the materials for the structure of the seedling. 78 THE VOLATILE PAiTT OF PLANTS. At spring-time, in cold climates, the starch stored up over winter in the new wood of many trees, especially the maple, appears to be converted into the saccharose which is found so abundantly in the sap, and this sugar, carried upwards to the buds, nourishes the young leaves, and is there transformed into cellulose, and into starch again. The sugar-beet root, when healthy, yields a juice containing 10 to 14 per cent of saccharose, and is destitute of starch. Schacht has observed that in a certain diseased state of the beet, its sugar is partially converted into starch, grains of this substance making their appearance. (Wida's Centralblatt, 1863, II., p. 217.) The analysis of the cereal grains sometimes reveals the presence of dextrin, at others of sugar or gum. Thus Stepf found no dextrin, but both gum and sugar in maize-meal, (Jou?. fiir Pr-kt. Chem., 76, p. 92;) while Fresenius, in a more recent analysis, (Vs. St., 1, p. 180,) obtained dextrin, but neither sugar or gum. The sample of maize examined by Stepf contained 3.05 p. c. gum and 3.71 p. c. sugar; that analyzed by Fresenius yielded 2.33 p. c. dextrin. Gum Tragacanth is a result of the transformation of cellulose, as Mohl has shown by its microscopic study. b. In the animal, the substances we have been describing also suffer transformation when employed as food. During the process of digestion, cellulose, so far as it is acted upon, starch, dextrin, and probably the gums, are all converted into glucose. c. Many of these changes may also be produced apart from physiological agency, by the action of heat, acids, and ferments, operating singly or jointly. Cellulose and starch are converted by boiling with a dilute acid, into dextrin and finally into glucose. If paper or cotton be placed in contact with strong chlorhydric acid, (spirit of salt,) it is gradually converted into the same sugar. Cellulose ar d starch acted upon for some time by strong nitric acid, (aqua-fortis,) give compounds from which dextrin may be separated. Nitrocellulose, (gun cotton,) sometimes yields gum by its spontaneous 70 HOW CROPS GROW. decomposition, (Hoffmann, Quart. Jour. k7hem. Soc., p. 767.) A kind of gum also appears in solutions of canesugar or in beet-juice, when they ferment' under certain conditions. Inulin and the gums yield sugar, (levulose,) but no dextrin, when boiled with weak acids. d. It will be noticed that while physical and chemical agencies produce these metamorphoses in one direction, it is only under the influence of life that they can be accomplished in the reverse manner. In the laboratory we can only reduce from a higher, organized, or more complex constitution to a lower and simpler one. In the vegetable, however, all these changes, and many more, take place with the greatest facility. The Chemical Composition of the Cellulose Grotv.It is a remarkable fact that all the substances just described stand very closely related to each other in chemical composition, while several of them are identical in this respect. In the following table their composition is expressed in formula. CHEMICAL FORMULE OF THE BODI)ES OF THE CELLULOSE GROUP. Cellulose Starch Inulin Dextrin C12 1120 010 Bassorin Veg. Mucilage Metarabic acid J Arabic acid 12 22 Cane sugar C5 H O Fruit sugar 12 24 12 Grape sugar It will be observed that all these bodies contain 12 atoms of carbon, united to as much hydrogen and oxygen as form 10, 11, or 12 molecules of water. We can, therefore, conceive of their conversion one into another, with no fairther change in chemical composition in any case, than the loss or gain of a few molecules of water. 80 THE VOLATILE PART OF PLANTS. Isormerisn.-Bodies which-like cellulose and dextrin, or like levulose and glucose-are identical in composition, and yet are characterized by different properties and modes of occurrence, are termed isomneric; they are examples of isomerism. These words are of Greek derivation, and signify of equtal measure. We must suppose that the particles of isomeric bodies which are composed of the same kinds of matter and in the same quantities, exist in different states of arrangement. The mason can build from a given number of bricks and a certain amount of mortar, a simple wall, an aqueduct, a bridge or a castle. The composition of these unlike structures may be the same, both in kind and quantity; but the structures themselves differ immensely, from the fact of the diverse arrangement of their ma. terials. In the same manner we may suppose starch to be converted into dextrin by a change in the relative positions of the atoms of carbon, hydrogen, and oxygen, which compose them. 3. THE PECTOSE GROuP.-The pectose group includes Pectose, Pectin, Pectosic, Pectic, and lVetapectic acids. These bodies exist in, or are derived from, fleshy fruits, including pumpkins and squashes, berries, the roots of the turnip, beet, onion, and carrot, and in cabbage and celery. They are an important part of the food of men and cattle. Pectose is the name given to a body which is supposed rather than demonstrated tQ occur with cellulose in the flesh of unripe fruits, and in the roots of turnips, carrots, and beets. Its characters in the pure state are as good as unknown, because we are as yet acquainted with no means of separating it from cellulose without changing its nature. Pectose is thought to constitute the chief bulk of the dry matter of the above-mentioned fruits and roots, and is concluded to be a distinct body by the products of its transformation, either such as are formed naturally, or those procured by artificial means. In what follows, we shall assume, with Fremy, (Ann. de Chim. et de Phys., XXIV, 6,) that pectose exists, and is the source of pectin, etc. Pectin is produced from pectose in a manner similar to that by which dextrin is obtained from cellulose or starch, viz., by the action of heat, of acids, and of ferments. When the flesh of fruits, or the roots which consist chiefly of 4* 81 HOW CROPS GROW. pectose, are subjected to the joint action of a moderate heat and an acid, the starch they contain is slowly altered into dextrin and sugar, while the firm pectose shortly softens, becomes soluble in water, and is converted into pectin. It is precisely these changes which occur in the bak ing of apples and pears, and in the boiling of turnips, car rots, etc., with water. In the ripening of firuits the same transformation takes place. The firm pectose, under the influence of the acids that exist in all fiuits, gradually softens, and passes into pectin. Exp. 33.-Express, and, if turbid, filter through muslin the juice of a ripe apple, pear, or peach. Add to the clear liquid its own bulk of alcohol. Pectin is precipitated as a stringy, gelatinous mass, vwhich, on drying, shrinks greatly in bulk, and forms, if pure, a white substance that may be easily reduced to powder, and is rcadfy soluble in cold water. Exr. 34.-Reduce several white turnips or beets to pulp by grating. Inclose the pulp in a piece of muslin, and wash by squeezing in water until all soluble matters are removed, or until the water comes off nearly tasteless. Biring the washed pulp into a glass vessel, with enough dilute chlorhydric acid, (1 part by bulk of commercial muriatic acid to 15 parts of water,) to saturate the mass, and let it stand 48 hours. Squeeze out the acid liquid, filter it, and add alcohol, when pectin will separate. The strong aqueous solution of pectin is viscid or gummy, as seen in the juice that exudes from baked apples or pears. Pectosic and Pectic acids.-Under the action of a ferment occurring in many fruits, assisted by a gentle heat, pectin is transformed first into pectosic, and afterward into pectic acid. These bodies compose the well-known fruitjellies. They are both insoluble in cold water, and remain suspended in it as a gelatinous mass. Pectosic acid is soluble in boiling water, and hence most fruit jellies become liquid when heated to boiling; on cooling, its solution gelatinizes again. Pectic acid is insoluble even in boiling water. It is formed also when the pulp of fruits or roots containing pectose is acted on by alkalies or by ammonia-oxide of copper. The latter agent, (a solvent of cellulose,) converts pectose directly into pectic acid, 82 THlE VOLATILE PART OF PLANTS. which remains in insoluble combination with oxide of copper. lMetapectic acid.-By too long boiling, by prolonged contact with acids or alkalies, and by decay, the pectic and pectosic acids, as well as pectin, are transformed into still another substance, viz., metapectie acid, which, according to Fremy, is a very soluble body of quite sour taste. It is the last product of the transformation of the bodies of this group with which we are acquainted. It exists, according to Fremy, in beet-molasses and decayed fruits. Exp. 35.-Stew a handful of sound cranberries, covered with water, just long enough to make them soft. Observe the speedy solution of the firm pectose. Strain through muslin. The juice contains soluble pectin, which may be precipitated from a small portion by alcohol. Keep the remaining juice heated to near the boiling point in a water bathl, (i. e., by immersing the vessel containing it in a larger one of boiling water.) After a time, which is variable according to the condition of the fruit, and must be ascertained by trial, the juice on cooling or standing solidifies to a jelly, that dissolves on warming, and reappears again on cooling-Fremy's pectosic acid. By further heating, the juice may form a jelly which is permanent when hot-pectic acid-and on still longer exposure to the same temperature, this jelly may dissolve again, by passing into Fremy's metapectic acid, which alcohol does not precipitate. Other ripe firuits, as quinces, strawberries, peaches, grapes, apples, etc., may be employed for this experiment, but in any case the time required for the juice to run through these changes cannot be predicted safely, and the student may easily fail in attempting to follow them. Chenmical composition of the Pectose group.-Our knowledge on this point is very imperfect. Pectose itself, having never been obtained pure, has not been analysed. The other bodies of this group have been examined, but, owing to the difficulty of obtaining them in a state of purity, the results of different observers are discordant. The formulae of FREMY are as follows: Pectose, unknown. Pectin, C32 H40 028 + 4 fi2 0 Pectosic acid, C18 H20 014 + 13 H2 0 Pectic acid, C01 H20 014 + 112 0 Metapectic acid, C. Hi0 07 + 2 H12 0 Grouven, (2ter Salzmunder Bericat, p. 470,) has prepared pectin on the large scale from beet-root cake, (remaining after the juice was expressed for sugar imanufacture,) by 83 HOW CROPS GROW. digesting it with cold dilute chlorhydric acid, precipitat ing and washing with alcohol. Thus obtained, it had all the characters ascribed to pectin. Its centesimal composition, however, corresponded nearly with that assigned by Fremy to pectic acid, and differs somewhat firom that given by this chemist for pectin, as is seen from the subjoined figures: Garouven's pectin. Pectin. C32 H4s 032 Carbon........ 40.67 Hydrogen......... 5.08 Oxygen...........54.25 100.00 From the best analyses and firom analogy with cellulose it is probable that pectose has the same composition as pectin, or differs from it only by a few molecules of water. If we subtract the water, which in the formulae (p. 83) is separated by + from the remaining symbol, we see that the proportions of Carbon, Hydrogen, and Oxygen are the same in all these bodies, and correspond to the formula C8 H,0 7O,. This nearness of composition assists in coinmprehending the ease with which the transformations of pectose into the other members of the gr'oup are effected. Relations of the Cellulose and Pectose Groups.-It was formerly thought that the pectin bodies are convertible into sugar by the prolonged action of acids. Fremy has shown that this is not the case. Sacc, (Ann. Ch. et Phys., 25, 218,) and Porter, (Ann. Ch. et Pharm., 71, 115,) have investigated a body having the properties and nearly the composition of pectic acid, which is produced by the action of nitric acid on wood. Divers, (oeour. Chem. Soc., 1863, p. 91,) has observed a substance having the essential characters of pectic acid among the products of the spontaneous decomposition of nitrocellulose, (gun cotton.) It is probable, though not yet fairly demonstrated, 84 Pectic acid. C,6 H22 015 1 42.29 4.84 52.87 100.00 42.95 5.44 51.61 100.00 THE VOLATILE PART OF PLANTS. that in the living plant cellulose passes into pectose and pectin. Without doubt, also, the reverse transformations may be readily accomplished. 4. THE VEGETABLE AcIDs.-The Vegetable Acids are very numerous. Some of them are found in all classes of plants, and nearly every family of the vegetable kingdom contains one or several acids peculiar to itself. Those which concern us here are few in number, and though doubtless of the highest importance in the economy of vegetation, are of subordinate interest to the objects of this work, and will be noticed but briefly. They are oxalic, tartaric, malic, and citric acids. They occur in plants either in the firee state, or as salts of lime, potash, etc. They are mostly found in fruits. Oxalic acids C. H2 04 2 H2 0, exists largely in the common sorrel, and, according to the best observers, is found in greater or less quantity in nearly all plants. The pure \ /) acid presents itself in the form of colorless, brilliant, transparent crystals, not Fig. 15 unlike Epsom salts in appearance, (Fig. 15,) but having an intensely sour taste. Oxalic acid forms with lime a salthe oxalate of lime -which is insoluble in pure water. It nevertheless exists dissolved in the cells of plants, so long as they are in active growth, (Schmidt, Ann. Chem. u. Pharm., 61,297.) Towards the end of the period of growth, it often accumulates in such quantity as to separate in microscopic crystals. These are found in large quantity in the mature leaves and roots of the beet, in the root of garden rhubarb, and especially in many lichens. Oxalate of potash is soluble in water, and exists in the juices of sorrel and garden rhubarb. It was formerly used for removing ink-stains from cloth and leather, under the name of salt of sorrel. Oxalic acid is now employed for this purpose. Oxalate of soda is soluble in water, and 85 HOW UROPS GROW. is found in the juices of plants that grow on the sea-shore Oxalate of ammonia is employed as a test for lime. Exp. 36.-Dissolve 5 giims of oxalic acid in 50 c. c. of hot water, add solution of ammonia or solid carbonate of ammonia until the odor of the latter slightly prevails, and allow the liquid to cool slowly. Long, needle like crystals of a salt of oxalic acid and ammonia-the oxalate of ammoia -separate on cooling, the compound being sparingly soluble in cold water. Preserve for future use. Exp. 37.-Add to any solution of lime, as lime-water, (see note, p. 36,) ~r hard well water, a few drops of oxalate of ammonia solution. Oxalate of lime immediately appears as a white powdery precipitate, which, fromn its extreme insolubility, serves to indicate the presence of the minutest quantities of lime. Add a few drops of chlorhydric or nitric acid to the oxalate of lime; it disappears. IHence oxalate of ammonia is a test fo lime only in solutions containing no free mineral acid. (Acetic ana oxalic acids, however, have little effect upon the test.) Deofitition of Acids, Bases, and Salts.-In the popular sense, ai atcid is any body having a sour taste. It is, in fact, true that all sour substances are acids, but all acids are not soui, some being tasteless, others bitter, and some sweet. A better characteristic of an acid is its capability of combining chemically with bases. The strongest acids, i. e. those bodies whose acid characters are most strongly developed, if soluble, so as to have any effect on the nerves of taste, are sour, viz., sulphuric acid, phosphoric acid, nitric acid, etc. Bases are the opposite of acids. The strongest bases, when soluble, are bitter and biting to the taste, and corrode the skin. Potash, soda, ammonia, and lime, are examples. Magnesia, oxide of iron, and many other coinpounds of metals with oxygen, are insoluble bases, and hence destitute of taste. Potash, soda, and ammonia, are termned alkalies; lime and magnesia, alkali-earths. Salts are compounds of acids End bases, or at least result from their chemical union. Thus, in Exp. 20, the salt, phosphate of lime, was produced by bringing together phosphoric acid, and the base, lime. In Exp. 37, oxalate of lime was made in a similar mannelr. Common salt-in 66 THE VOLATILE PART OF PLANTS. chemical language, chloride of sodium-is formed when soda is mixed with chlorhydric acid, water being, in this case, produced at the same time. Testfo) acids and alkalies.-Many vegetable colors are altered by soloble acids or soluble bases, (alkalies,) in such a manner as to answer the purpose of distinguishing these two classes of bodies. A solution of cochineal may be employed. It has a ruby-red color when concentrated, but on mixing with much pure water, becomes orange or yellowishorange. Acids do not affect this color, while alkalies turn it to an intense carmine or violet-carmine, which is restored to orange by acids. Exp. 38.-Prepare tincture* of cochineal by pulverizing 3 grams of cochineal, and shaking frequently with a mixture of 50 c. c. of strong alcohol and 200 c. c. of water. After a day or two, pour off the clear liquid for use. To a cup of water add a few drops of strong sulphuric acid, and to another similar quantity add as many drops of ammonia. To the liquids add separately 5 drops of cochineal tincture, observing the coloration in each case. Divide the dilute ammonia into two portions, and pour into one of them the dilute acid, until the carmine color just passes into orange. Should excess of acid have been incautiously used, add ammonia, until the carmine reappears, and destroy it again by new portions of acid, added dropwise. The acid and base thus neutralize each other, and the solution contains sulphate of ammonia, but no free acid or base. It will he found that the orange-cochineal indicates very minute quantities of ammonia, and the carmine-cochineal correspondingly small quantities of acid. Tincture of litmus, (procurable of the apothecary,) or of dried red cabbage, may also be employed. Litmus is made red by soluble acids, and blue by soluble bases. With red cabbage, acids develope a purple, and the bases a green color. In the formation of salts, the acids and bases more or less neutralize each other's properties, and their compounds, when soluble, have a less sour or less acrid taste, and act less vigorously on vegetable colors than the acids or bases themselves. Some soluble salts have no taste at all resembling either their base or acid, and have no effect on vegetable colors. This is true of common salt, glauber salts or sulphate of soda, and saltpeter or nitrate of potash. Others exhibit the properties of their base, though in a reduced degree. Carbonate of ammonia, for example, has much of the odor, taste, and effect on vegetable colors that belong to ammonia. Carbonate of soda has the taste and other properties of caustic soda in a greatly mitigated form. On the other hand, s ulphates of alumina, iron, and copper, have slightly acid characters. Certain acids form with the same base several distinct salts. Thus carbonic acid and soda may produce carbonate of soda, Na20 C02, or * Tinctures, in the language of the apothecary, are alcoholic solutio(ns. 87 HOW CROPS GROW. bicarbonate of soda, Na H 0 CO,. The latter is mu th less alkaline than the former, but both turn cochineal to a carmine color. Again, phosphoric acid may form three distinct salts with soda or with lime, which will be noticed in another place. Oxalic acid also yields several kinds of salts, as do the other organic acids presently to be described. Malic acid C, H4 05, is the chief sour principle of apples, currants, gooseberries, plums, cherries, strawberries, and most common fruits. It exists in small quantity in a multitude of plants. It is found abundantly in combination with potash, in the garden rhubarb, and malate of potash may be obtained in crystals by simply evaporating the juice of the leaf-stalks of this plant. It is likewise abundant as lime-salt in the nearly ripe berries of the mountain ash, and in barberries. Malate of lime also occurs in considerable quantity in the leaves of tobacco, and is often encountered in the manufacture of maple sugar, separating as a white or gray sandy powder during the evaporation of the sap. Pure malic acid is only seen in the chemical laboratory, and presents white, crystalline masses of an intensely sour taste. It is extremely soluble inll water. Tartaric acid, C4 II6 06, is abundant in the grape, from the juice of which, during fermentation, it is deposited in combination with potash as argol. This, on purification, yields the cream of tartar, (bitartrate of potash,) of commerce. Tartrates of potash or lime exist in small quantities in tamarinds, in the unripe ber- Fig. 16. ries of the mountain ash, in the berries of tlie sumach, in cucumbers, potatoes, pine-apples, and many other fruits. The acid itself may be obtained in large glassy crystals, (see Fig. 16,) which are very sour to the taste. Citric acid, C6 H8 0,, exists in the free state in the juice of the lemon, and in unripe tomatoes. It accompanies malic acid in the currant, gooseberry, cherry, strawberry, and raspberry. It is found in small quantity, united to 88 THE VOLATILE PART OF PLANTS. lime, in tobacco leaves, in the tubers of the Jerusalem artichoke, in the bulbs of onions, in beet roots, in coffeeberries, and in the needles of the fir tree. In the pure state, citric acid forms large transparent or white crystals, very sour to the taste. Relations of the Tegetable Acids to each othe) anid to the Amnyloids.-The four acids above noticed usually occur together in our ordinary fruits and it appears that some of them undergo mutual conversiou in the liv ing plant. According to Liebig, the unripe berries of the mountain ash contain much tartaric acid, which, as the fruit ripens, is converted into malic acid. Schmidt, (Ansi.. Chem. u. Pham-si., 114, 109,) first showed that tartaric acid can be artificially transformed into malic'teiL Tihe chemical change c)nsists merely in the removal of one atom of oxygen. Tartaric acid. Malic acid. C4 H6 06 - 0 - C4 H6 05 When citric, malic, and tartaric acids are boiled with nitric acid, or heated with caustic potash, they all yield oxalic acid. Cellulose, starch, dextrin, the sugars, and, according to some, pectic acid, yield oxalic acid, when heated with potash or nitric acid. Commercial oxalic acid is thus made from starch and from saw-dust. Gum (Arabic,) sugar, starch, and, according to some, pectin, yield tartaric acid by the action of nitric acid. 5. FATS AND OILS (WAX).-vVe have only space here to notice this important class of bodies in a very general mannier. In all plants and nearly all parts of plants we find some representatives of this group; but it is chiefly in certain seeds that they occur most abundantly. Thus the seeds of hemp, flax, colza, cotton, bayberry, pea-nut, butternut, beech, hickory, almond, sunflower, etc., contain 10 to 70 per cent of oil, which may be in great part removed by pressure. In some plants, as the common bayberry, and the tallow-tree of Nicaragua, the fat is solid at ordinary temperatures, and must be extracted by aid of heat; while, in most cases, the fatty matter is liquid. The cereal grains, especially oats and maize, contain oil in appreciable quantity. The mode of occurrence of oil in plants is shown in fig. 17, which represents a highly magnified section of the flax-seed. The oil exists 89 IIOW CROPS GROW. as minute, transparent globules ill the cells, f. Fi-om these seeds the oil may be completely extracted by ether, benzine, or sulphide of carbon, which dissolve all fats with readi 1(111! ~iness, but scarcely affect the other 2. m;~< vegetable principles. Many plants yield small quan {[ lOLO [ [[I ~tities of wax, which either gives a d =[_ glossy coat to their leaves, or ~~~ ~;~ fm~o-ms a bloom upon their fruit. The lower leaves of the oat plant at the time of blossom contain, in -" ~ ~ the dry state, 10 per cent of fat Fit 17. and wax, (Arendt). Scarcely two of these oils, fats, or kinds of wax, are exactly alike in their properties. They differ more or less in taste, odor, and consistency, as well as in their chemical composition. Exr. 39-Place a handful of fine and fresh corn or oat meal which has been dried for an hour or so at a heat not exceeding 212~, in a bottle. Pour on twice its bull. of ether, cork tightly, and agitate frequently for half an hour. Drain off the liquid (filter, if need be) into a clean'porcelain dish, and allow the ether to evaporate. A yellowish oil remains, which, by gently warming for some time, loses the smell of ether and becomes quite pure. The fatty oils must not be confounded with the ethereal, essential, or volatile oils. The former do not evaporate except at a high temperature, and when brought upon paper leave a permanent "grease-spot." The latter readily volatilize, leaving no trace of their presence. The formei', when pure, are without smell or taste. The latter usually possess marked odors, which adapt many of them to use, as perfumes. In the animal body, fat (in some insects, wax,) is formed or appropriated from the food, and accumulates in considerable quantities. How to feed an animal so as to cause the most rapid and economical fattening is one of the most important questions of agricultural chemistry. 90 THE VOLATILE PART OF PLAN TS. However greatly the various fats may differ in external characters, they are all mixtures of a few elementary fats. The most abundant and commonly occurring fats, especially those which are ingredients of the food of man and domestic animals, viz.: tallow, olive oil, and butter, consist essentially of three substances, which we may briefly notice. These elementary fats are Stearin, Palmitin, and Olein,* and they consist of carbon, oxygen, and hydrogen, the first-named element being greatly preponderant. Stearin is represented by the formula C5 11110 06. It is the most abundant ingredient of the common fats, and exists in largest proportion in the harder kinds of tallow. Exp. 40.-Heat mutton or beef tallow, in a bottle that may be tightly corked, with ten times its bulk of concentrated ether, until a clear solution is obtained. Let cool slowly, when stearin will crystallize out in pearly scales. Palmitin, C51, H18 06, receives its name from the palm (il, of Africa, in which it is a large ingredient. It forms a good part of butter, and is one of the chief constituents of bees-wax, and of bayberry tallow. Olein, C57 11104 06, is the liquid ingredient of fats, and occurs most abundantly in the oils. It is prepared from olive oil by cooling down to the freezing point, when the stearin and palmitin solidify, leaving the olein still in the liquid state. Other elementary fits, viz.: butyrin, lauri, myristin, etc., occur in small quantity in butter, and in various vegetable oils. Flaxseed oil contains linolein; castor oil, ricinolein, etc. We have already given the formulae of the principal fats, but for our purposes, a better idea of their comnposition may be gathered from a centesimal statement, viz..: * Margarin, formerly thought to be a distinct fat, is a mixture of stearin and palmitin. 91 HOW CROPS GROW. CENTESIMAL COMPOSITION OF THE ELEMENTARY PAT. Pan mitin. 75.9 12.2 11.9 Carbon, Hydrogen, Oxygen, 100.0 100.0 100.0 Phosphorized Fats.-The animal brain and spinal cord, and the yolk of the egg, contain a considerable amount of fat which has long been characterized by a small content of phosphorus. Von Bib]a found the quantity of phosphorus in this (impure) fat to range from 1.21 to 2.53 per cent. Knop ( V. St. 1, p.26) was the first to show that analogous phosphorized fats exist in plants. From the sugar pea he extracted 2.5 per cent of a thick brown oil, which was free from sulphur and nitrogen, but contained 1.25 per cent of phosphorus. The composition of this oil was as follows: Carbon...................................66.85 Hydrogen................................ 9.52 Oxygen..................................22.38 Phosphorus.............................. 1.25 100.00 T6pler (fenneberg's Jahresbericht 1859-1860, p. 164) subsequently examined the oils of a large number of seeds for phosphorus with the subjoined results: Source of Per cent of Source of T.r cent of fit. phosphorus.| fat. pthophorus. Lupine...............0.29 Walnut..............trace Pea.................1.17 Olive................none Horse bean.......... 0.72 Wheat................0.25 Vetch.................0.50 Barley................0.28 Winter lentil.........0.39 Rye..................0.31 Horse-chestnut.......0.30 Oat............... 0.44 Chocolate bean......none Flax.................none Millet............... " Colza................ Poppy............... " Mustard............ 92 Stearin. 76.6 12.4 10.0 Otein. 77.4 11.8 10.8 /-Z THE VOLATILE PART OF PLANR'S. According to Hoppe-Seyler, (led. Chem. Uterts., I,) the phosphorized principle of oil of maize, and of the brain, nerves, yolk of eggs, etc., is primarily the substance discovered in 1864 by Liebreich, in the brain, and termed Protagon. It is a white crystallized body, having the following composition: Carbon, 67.2 Hydrogen, 11.6 Nitrogen, 2.7 Phosphorus, 1.5 Oxygen, 17.0 100.0 Its formula is C016, I241, N4, P, 022. When heated to the boiling point it is decomposed, and yields among other products glycerin, phosphoric acid, and stearic acid. (Ann. C7h. Ph., 134, p. 30). Saponifycation.-The fats are characterized by forming soaps when heated with strong potash or soda-lye. They are by this means decomposed, and give rise to fatty acids, which remain combined with the alkalies, and to glycerin, a kind of liquid sugar. Exp. 41.-Heat a bit of tallow with strong solution of caustic potash until it completely disappears, and a soap, soluble in water, is obtained. To one-half the hot solution of soap, add chlorhydric acid until the latter predomiates. An oil will separate which gathers at the top of the liquid, uad on cooling, solidifies to a cake. This is not, however, the original fit. It has a different melting point, and a different chlemical composition. It is composed of one or several fatty acids, corresponding to the elementary fats fiom which it was produced. When saponified by the action of potash, stearin yields atearic acid, C18 H16 O2; palmitin yields palmitic acid, Cl6 32, O; and olein gives oleic acid, C,- H.,, O. The so-called stearin candles are a mixture of stearic and palmitic acids. The glycerin, C. H1 O3, that is simultaneously produced, remains dissolved in the liquid. Glycerin is now found in commerce in a nearly pure state, as a colorless, syrupy liquid, having a pleasant sweet taste. The chemical act of saponification consists in the re-arrangement of the elements of one molecule of fat and three molecules of water into three molecules of fatty acid, and one molecule of glycerin. Palmitin Water. Palmitic acid. Glycerin. Osl H98 08 + 3 (H2 0) - 3 (C0s H32 02) + C3 0 8 ~ 93 HOW CROPS GROW. Saponification is likewise effected by the influence of strong acids and by heating with water alone to a temperature of near 400~ F. Ordinary soap is nothing more than a mixture of stearate, palmitate, an;l oleate of potash of soda, with or without glycerin. Common soft soap consists of the potash-compounds of the above-named acids, mixed with glycerin and water. Hard soap is usually the corresponding soda-compound, fiee from glycerin. Whlen soft potash-soap is boiled with common salt (chloride of sodium), hard soda-soap and chloride of potassium are formed by transposition of the ingredients. On cooling, soda-soap forms a solid cake upon the liquid, and the glycerin remains dissolved in the latter. Relations of Fats to Amyloids. - The oil or fat of plants is in many cases a product of the transformation of starch or other member of the cellulose group, for the oily seeds, when immature, contain starch, which vanishles as they ripen, and in the sugar-cane the quantity of wax is said to be largest when the sugar is least abundant, and vice versa. In germination the oil of the seed is converted back again into starch, sugar, etc. The E.stimation of Fat (including wax) is made by warming the pulverized and dry substance repeatedly with renewed quantities of ether, or sulphide of carbon, as long as the solvent takes up anything. On evaporating the solutions, the fat remains nearly in a state of purity, and after drying thoroughly, may be weighed. PROPORTIONS OF FAT IN VARIOUS VEGETABLE PRODUCTS. Per cent. Turnip................. 0.1 Wheat kernel........... 1.6 Oat ".......... 1.6 Maize ".......... 7.0 Pea ".......... 3.0 Cotton secd............34.0 Flax "............ 34.0 - Colza "............450 Meadow grass............. 0.8 Red clover (green)....... 0.7 Cabbage................. 0.4 Meadow hay............. 3.0 Clover hay.............. 3.2 Wheat straw.............1.5 Oat straw..........2.0 Wheat bran..............1.5 Potato tuber.............0.3 6. TiHE ALBUMINOIDS OR PROTEIN BODIES.-The bodies of this class differ from the groups hitherto noticed in the fact of their containing in addition to carbon, oxygen, and hydrogen, 15 to 18 per cent of nitrogen, with a small quantity of suphzur, and, in some cases, phosphorus. 94 lbr cent. THE VOLATILE PART OF PLANTS. In plants, the i eotein Bodies occur in a variety of inodifications, and though found in small proportion in all their parts, being everywhere necessary to growth, they are chiefly accumulated in the seeds, especially in those of the cereal and leguminous grains. The albuminoids, as we shall designate them, that occur in plants, are so similar in many characters, are, in fact, so nearly identical with the albuminoids which constitute a large portion of every animal organism, that we may advantageously consider them in connection. We may describe the most of these bodies under three sub-groups. The type of the first is albumin, or the white of egg; of the second,.fbrin, or animal muscle; of the third, casein, or the curd of milk. Comnmoi? Characters.-The greater number of these substances occur in several, at least two, modifications, one soluble, the other insoluble in water. In living or undecayed animals and plants we find the albuminoids in the soluble, and, ill fact, in the dissolved state. They may be obtained in the solid form by evaporating off at a gentle heat the water which is naturally associated with them. They are thus mostly obtained as transparent, colorless or yellowish solids, destitute of odor or taste, which dissolve again in water, but are insoluble in alcohol. Recently, both in the animal and vegetable, soluble albuminoids have been observed in colorless or red crystals, (or crystalloids,) often of considerable size, but so associated with other bodies as, in general, not to admit of separation in the pure state. The insol?ble albuminoids, some of which also occur naturally in plants and animals, are, when purified as much as possible, white, flocky, lumpy or fibrous bodies, quite odorless and tasteless. As further regards the deportment of the albuminoids towards solvents, some are dissolved in alcohol, none in ether. They are soluble in 95 HOW CROPS GROW. po)tasll and soda-lyc; acids separate them from these solutions, strong acetic acid dissolves them with one exception. In very dilute mineral acids (sulpiluric and chlilorhydric) some of them dissolve in great part, others swell up like jelly. Coagulation.-A remarkable characteristic of the group of bodies now under notice is their ready conversion from the soluble to the insoluble state. In some cases this coagulation happens spontaneously, in others by elevation of temperature, or by contact with acids, metallic oxides, or various salts. The albuminoids, when subjected to heat, melt and burn with a smoky flame and a peculiar odor-that of bumnt hair or horn,-while a shining charcoal remains which is difficult to consume. Tests for the Albuminoids.-The chemist employs the behavior of the albuminoids towards a number of reagents * as tests for their presence. Some of these are so delicate and characteristic as to allow the distinction of this class of substances fiom all others, even in microscopic observations. 1. Iodine colors them intensely yellow or bronze. 2. Warm and strong chlorhydric acid colors all these bodies blue or violet, or, if applied in large excess, dissolves them to a liquid of these colors. 3. In contact with nitric acid they are stained a deep and vivid yellow. Silk and wool, which consist of bodies closely approaching the albuminolds in composition, are commonly dyed or printed yellow by means of nitric acid. 4. A solution of nitrate of mercury in excess of nitric acid, t tinges them of a deep red color. This test enables us to detect albumin, for example, even where it is dissolved in 100,000 parts of water. Albumin.-Animal Albumin.-The white of a hen's egg on drying yields about 12 per cent of albumin in a state of tolerable purity. The fresh white of egg serves * Reagents are substances commonly employed for the recognition of bodies, or, generally, to produce chemical changes. All chemical phenomena result from the mutual action of at least two elements, which thus act and react on each other. Hence the substance that excites chemical changes is termed a reagent, and the phenomena or results of its application are called reactions. t This solution, known as Millon's test, is prepared by dissolving mercury in its own weight of nitric acid of sp. gr. 1.4, heating towards the close of the process, and finally adding to the liquid twice its bulk of water. 06 THE VOLATILE PART OF PLANTS. to illustrate the peculiaritiesof this substance, and to exhibit the deportment of the albuminoils generally towards the above-named reagents. Ex-P. 42.-Beat or whip the white of an egg so as to desti-oy the delicate transparent membrane in the cells of which the albumin is held, and agitate a portion of it with water; observe that it dissolves readily ill the latter. ExP. 43.-Heat a part of the undiluted white of egg in a tube ol culp at 165~ F.; it becomes opaque, white, and solid, (coag'ula.tes) and is converted into the insoluble modification. A higiher heat is needful to coagulate solutions of albumin, in proportion as they are diluted with water. Exp. 44.-Add strong alcohol to a portion of the solution of albumin of Exp. 42. It produces coagulatioii. ExP. 45.-Observe that albuniin is coagulated by dilute acids tpplied iii small quantity, especially by nitric alcid. ExP. 46.-Put a little albumin, either soluble or coagulated, into each of four test tubes. To one, add solution of iodine; to a second, strong chlorhydric acid; to a third, nitric acid; and to the last, nitrate of mercury. Observe the characteristic colorations that appear immediately, or after a time, as described above. In the last three cases the reaction is hastened by a gentle heat. Albumin occurs in the soluble folm in the blood, and in all the liquids of the healthy animal body except the urine. In some cases its characters are slightly different from those of egg-albutmin. The albumin of the blood, which may be separated by heating blood-serum (the clear yellow liquid that floats above the clot), contains a little less sulphur than coagulated egg-albumin. In the crystalline lens of the eye, and in the blood corpuscles, the albumin has again slightly different characters, and has been termed globulin. Under certain conditions the blood of animals yields a substance known as hemoglobin, which, while having nearly the composition and many of the properties of albumin, commonly requires a much larger proportion of water for solution, and forms distinct crystals of a transparent red color. Vegetable Albumin.-In the juices of all plants is found - minute quantity of a substance which agrees in nearly all respects with animal albumin, and is hence termed 5 97 sROW CROPS GROW. vegetable albumin. The clear juice of the potato tuber (which may be procured b;y grating potatoes, squeezing the pulp in a cloth, and letting the liquor thus obtained stand in a cool place until the starch has deposited,) contains albumin in solution, as may be shown by heating to near the boiling point, when a coagulum separates, which, after boiling successively with alcohol and ether to remove fat and coloring matters, is scarcely to be distinguished, either in its chemical reactions or composition from the coagulated albumin of eggs. The juice of succulent vegetables, as cabbage, yields vegetable albumin in larger quantity, though less pure, by the same treatment. Water which has been agitated for some time in contact with flour of wheat, rye, oats, or barley, is found by the same method to have extracted albumin from these grains. The coagulum, thus prepared from any of these sources, exhibits the reactions characteristic of the albuminoids, when put in contact with nitrate of mercury, nitric or chlorhydric acid,. ExP. 47.-Prepare impure vegetable albumin from potatoes, cabbage, or flour, as above described, and apply the nitrate of mercury test. Fibrin.-Blood-Fibrin.-The blood of the higher animals, when in the body or when fresh drawn, is perfectly fluid. Shortly after it is taken from the veins it partially solidifies -it coagulates or becomes clotted. It hereby separates into two portions, a clear, pale-yellow liquidthe serum, and the clot. As already stated, the serum contains albumin. The clot consists chiefly of fibrin. On squeezing and washing the clot with water, the coloring matter of the blood is removed, and a white stringy mass remains, which is one form of the substance in question. Blood-fibrin is not known in the soluble state, except in fresh blood, from which it cannot be separated, as it so soon coagulates spontaneously. Prepared as just described, fibrin has many of the propertiep of albumin. Placed in a solution of saltpeter, espe 98 THE VOLATILE PART OF PLANTS. cially if a little potash lye be added, it dissolves in a few days to a clear liquid, which coagulates on heating or by addition of metallic salts, in the same manner as a solution of albumin. In very dilute bchlorhydric acid, it swells up, but does not dissolve. Exp. -Observe the separation of blood into clot and serum; coagulate the albumin of the former by heat, and test it with warm cblorhydric acid. Tie up the clot in a piece of muslin, and squeeze and washl in water until coloring matter ceases to run off. Warm it with nitric icid as a test. Fleshfibrin.-If a piece of lean beef or other meat be repeatedly squeezed and washed in water, the coloring matters are gradually removed, and a white residue is obtained, which resembles blood-fibrin in its external characters. It is, in fact, the actual fibers of the animal muscle, and hence its name. It is characterized by dissolving in very dilute chlorhydric acid, (one part acid and 1,000 of water) to a clear liquid, from which it is again separated by careful addition of an alkali, or a solution of common salt. Vegetable-fibrin.-When wheat-flour is mixed with a little water to a thick dough, and this is washed and kneaded for some time in a vessel of water, the starch and albumin are mostly removed, and a yellowish, tenacious mass remains, which bears the name gluten. When wheat is slowly chewed, the saliva carries off the starch and other matters, and the gluten mixed with bran is left behindwell-known to country lads as "wheat-gum." Exp. 49.-Wet a handful of good, firesl, wheat flour slowly with a little water to a sticky, dough, and squeeze this under a fine stream of water until the latter runs off clear. Hecat a portion of this gluten with MIillon's test. Gluten is a mixture of several albuminoids, and contains besides some starch and fat. Vegetable-fibrin is dissolved from it by alcohol, and separates on removing the alcohol by evaporation. The albuminoids of crude gluten dissolve in very dil ite potaslh-lye, .,. l iI,. HOW CROPS GROW. (one to oine and one-half parts potash to 1000 parts of water), and the liquid, after standing some days at rest, may be poured off from any residue of starch. On adding acetic acid ill slight excess, the purified albuminoids are separated in the solid state. By extracting successively with weak, with strong, and with absolute alcohol, a form of casein (gluten-caseit, of Ritthausen) remains undissolved, which is perhaps identical with the -asein (legumin) of the pea. On evaporating the alcoholic solution to one.half, there separates, on cooling, a brownish-yellow mass. This, when treated with absolute alcohol, leaves vegetable-fibsin nearly pure. Vegetable-fibrin is readily soluble in hot alcohol, but slightly so in cold alcohol. It does not at all dissolve in water. It has no fibrous structure like animal fibrin, but forms, when dry, a tough, horn-like mass. In composition it approaches animal-fibrin. Casein.-Animal casein is the peculiar ingredient of new cheese, It exists dissolved to the extent of 3 to 6 per cent in fresh milk, unlike albumin is not coagulated by heat, but is coagulated by acids, by rennet, (the membrane of the calf's stomach), and by heating to boiling with salts of lime and magnesia. Exp. 50.-Observe the coagulation of casein when milk is treated with a few drops of sulphuric acid. Test the curd with nitrate of mercury. ExP. 51.-Boil milk with a little sulphate of magnesia (epsom salts) until it curdles. When casein is separated from milk by rennet, as in making cheese, it carries with it a considerable portion of the phosphates and other salts of the milk; these salts are not found in the casein precipitated by acids, being held in solution by the latter. The casein of milk coagulates spontaneously when it stands for some time. Casein has recently been detected in the brain of animals. (Hioppe-Seyler, M[ed. CIem. Uiters., II.) Vegetable casein.-This substance is found in large proportion (17 to 19 per cent) in the pea and bean, and indeed generally in the seeds of the so-called leguminous plants. It closely re sembles milk-casein in all respects. too ,i - -, -,..: I - THE VOLATILE PART OF PLANTS. ExP 52.-Prepare a solution of vegetable casein from crushed peas, oats, almonds, or pea-nuts, by soaking them for some hours in warm water, and allowing the liquid to settle clear. Coagulate the casein by addition of an acid to the solution. It may be coagulated by rennet, and by salts of magnesia and lime, in the same manner as animal casein. The Chinese prepare a vegetable cheese by boiling peas to a pap, straining the liquor, adding gypsum until coagulation occurs, and treating the curd thus obtained in the same manner as practiced with milk-cheese, viz. salting, pressing, and keeping until the odor and taste of cheese are developed. It is cheaply sold in the streets of Canton under the name of Tao-foo. Vegetable casein occurs in small quantity in oats, the potato, and many plants; and may be exhibited by adding a few drops of acetic acid to turnip juice, for instance, which has been freed from albumin by boiling and filtering. The casein from peas and leguminous seeds has been designated tegumin, that of the oat has been named avenin. Almonds yield a casein, which has been termed emusin. As already mentioned, casein (Ritthausen's gluten-casein) exists in wheat-gluten, and in rye. Each of these sources yields a casein of somewhat peculiar characters; the causes of these differences are not yet ascertained, but probably lie in impurities, or result from mixture of other albuminoids. In crude wheat-gluten two other albuminoids exist, viz.: Gliadin, or vegetable glue, is very soluble in water and alcohol. It strongly resembles animal glue. Mucidin resembles gliadin, but is less soluble in strong alcohol, and is insoluble in water. When moist, it is yellowish-white in color, has a silky luster, and slimy consistence. It exists also in rye grain. (Ritthausen, Jour. fulr Prakt. Chem., 88, 141; and 99, 463.) Composition of the Albuminoids.-There are various reasons why the exact composition of the bodies just described is a subject of uncertainty. They are, in the first place, naturally mixed and associated with other matters 101 HOW CROPS GROW. from which it is very difficult to separate them fully Again, if we succeed in removing foreign substances, it must usually be done by the aid of acids, alkalies, and other strong reagents, which easily alter or destroy their proper characters and composition. Finally, if we analyze the pure substances, our methods of analysis are perhaps. scarcely delicate enough to indicate their differences with entire accuracy. The results of chemical investigation demonstrate that the albuminoids are either identical in composition or differ but slightly from each other, as is seen from the Table below. The deduction of a correct atomic formula from these analyses is perhaps impossible in the present state of our knowledge. In the subjoined Table are given analyses of the albuminoids which have been dscribed. Those indicated by asterisks are recent resuits of Dr. Ritthausen; the others are average statements of the best analyses, (after Gorup-Besanez, Org. Chlemnie, p. 611.) COMPOSITION OF ALBUMINOIDS. Cairbon. Hydrogen. Nitrogen. Oxygen. Sulphur. Animal albumin...... 53.5 Vegetable albumin.... 5 3.4 - Blood fibrin........... 52.6 Flesh fibrin........... 54.1 Wheat fibrln*........54.3Animal casein........ 53.6 Vegetable casein......50.5 - Gluten-casein* ].......51.0 Gliadin* wheat 52.6 Mucedin* J.....54.1 22.4 23.0 21.8 21.5 20.6 22.6 24.2 25.4 21.5 21.5 Phosphorus is not included in the above table, for the reason that in all cases its quantity, and in most instances its very presence, is still uncertain. Voelcker and Norton found in vegetable casein 1.4 to 2.3 per cent of phosphorus, and smaller quantities have been mentioned by other of the older analysts as occurring in albumin and fibrin. The phosphorus of these and of animal casein is thought not to belong to the albuminoid, but to be due to an admixture of phosphate of lime. In his recent investigation of gluten-casein, Rittl,tusen found phosphoric acid that appears to have been partially uncombined with a fixed base, and to have therefore resulted from phosphorus in )rganic combi 102 7.0 7.1 7.0 7.3 7.2 7.'l 6.8 6.7 7.0 6.9 15.5 15.6 17.4 16.0 16.9 15.7 18.0 16.1 18.1 16.6 1.6 0.9 1.2 1.1 1.0 1.0 0.5 0.8 0.8 ..O.9 THE VOLATILE PART OF PLANTS. nation. It is not unlikely that egetable casein may contain an admixture of protaron (p. 93), or the products of its decomposition, from which it is not easy to procure a separation. Mutttual Relations of the Albuminoids.- Some have supposed that these bodies are identical in composition, the differences among the analytical results being due to foreign matters, and differ from each other in the same way that cellulose and starch differ, viz.: on account of different arrangement of the atoms. Others formerly adopted the notion of Mulder, to the effect that the albuminoids are compounds of various proportions of hypothetical sulphur and phosphorus compounds, with a common ingredient, which he termed protein, (from the Greek signifying "to take the first place," because of the great physiological importance of such a body.) Hence the albuminoids are often called the protein-bodies. The transformations which these substances are capable of undergoing, sufficiently show that they are closely related, without, however, satisfactorily indicating in what manner. In the animal organism, the albuminoids of the food, of whatever name, are dissolved in the gastric juice of the stomach, and pass into the blood, where they.form bloodalbumin and blood-fibrin. As the blood nourishes the muscles, they are modified into flesh-fibrin, or entering the lacteal system, are converted into casein, while in the appropriate part of the circulation they are formed into the albumin of the egg, or embryo. In the living plant, similar changes of place and of character occur among these substances. Finally, outside the organism the following transforinations have been observed: Flesh-fibrin exposed while moist to the air at a sumn er temperature for some days, dissolves into a liquid; it this liquid be heated to near boiling, coagulation takes place, and the substance which separates has the properties of albumin. On removing the albumin and adding vinegar to the remaining liquid, 103 HOW CROPS GROW. a curdy coagulum is formed, which agrees in its properties with casein. (Bopp, Ann. Ch. Ph., 60, p. 30; Gunning, Jour. fuir Prakt. CAem., 69, p. 52.) Lehmann has shown that when albumin is dissolved in potash, and mixed with a little milk-sugar and oily fat, the mixture coagulates with rennet exactly as milk curdles. (Gornp-Besanez, Phys. Chem., p. 139.) Sullivan has observed that the casein of milk which was kept in closed air-tight vessels for a long time, at first coagulated, but afterward dissolved again to a nearly clear liquid, which was found to contain no casein, but by heating, coagulated, showing the conversion of casein into albumin, or a similar body. (Phil. Mag., 4, XVIII, 203.) Some maintain that casein is not a distinct albuminoid, but a compound of albumin with potash, containing, according to Lieberkuihn, 5.5~10 of this alkali. Its peculiarities are in part due to its natural association with phosphate of potash. Kt-hne, Phys. CAer., 1868, p. 565. See, however, Schwarzenbach, Ann. Ch. u. Ph., 144, p. 63. The Albuminoids in Animal Nutrition.-We step aside for a moment from our proper plan to direct attention to the beautiful adaptation of this group of organic substances to the nutrition of animals. Those bodies which we have just noticed as the animal albuminoids, together with others of similar composition, constitute a large share of the healthy animal organism, and especially characterize its actual working machinery, being essential ingredients of the muscles and cartilages, as well as of the nerves and brain. They likewise exist largely in the nutritive fluids of the animal-in blood and milk. So far as we know, the animal body has not the power to produce a particle of albumin, or fibrin, or casein; it can only transform these bodies as presented to it firom external sources. They are hence indispensable ingredients of food, and have been aptly designated by Liebig as the plastic elements of nutrition. It is, in all cases, the plant which originally con 104 THE VOLATILE PART OF PLANTS. structs these substances, and places them at the disposal of the animal. The albuminoids are mostly capable of existing in the liquid.or soluble state, and thus admit of distribution throughout the entire animal body, as blood, etc. They likewise readily assume the solid condition, thus becoming more permanent parts of the living organism, as well as capable of indefinite preservation for food in the seeds and other edible parts of plants. Complexity of Constitutio'.-The albuminoids are highly complex in their chemical constitution. This fact is shown as well by the multiplicity of substances which may be produced from them by destructive and decomposing processes, as by the ease with which they are broken up into other and simpler compounds. Subjected in the soluble or moist state to the action of warm air, they speedily decompose or putrefy, yielding a large variety of products. Heated with acids, alkalies, and oxidizing agents, they all give origin to the same or to analogous products, among which no less than twenty different compounds have been distinguished. Occutrreduce in Plcats —1eurone.-It is only in the old and virtually dead parts of a living plant that albuminoids are ever wanting. In the young and growing organs they are abundant, and exist dissolved in the sap or juices. They are especially abundant in seeds, and here they are deposited in an organized form, chiefly in grains similar to those of starch, and are nearly or altogether insoluble in water. These grains of albuminoid matter are not, min many cases at least, pure albuminoids. They appear to contain vegetable albumin, casein, fibrin, etc., associated together, though, in general, casein and fibrin are largely predominant. HIartig, who first described them minutely, has distinguished them by the name aleuroie, a term which we may conveniently employ. By the word aleurone is not 5. 105 HOW CROPS GROW. meant simply an albuminoid, or mixture of albuminoids, but the organized granules found in the plant, of which the albuminoids are chief ingredients. In Fig. 18 is represented a magnified slice through the outer cells, (bran,) of a husked oat kernel. The cavities of these outer cells, a, c, are chiefly occupied with very a-j ~ Fig. 19. fine grains of aleurone, (casein.) In one cell, b, are seen the much larger starch grains. In the interior of the oat kernel and other cereal seeds, the cells are chiefly occupied with starch, but throughout grains of aleurone are more or less intermingled. Fig. 19 exhibits a section of the exterior part of a flaxseed. The outer cells, a, contain vegetable mucilagre; the interior cells, e, are mostly filled with minute grains of aleurone, among which droplets of oil, f, are distributed. In Fig. 20 are / _: shown some of the forms assumed by in- dividual albuminoid- a b c d e grains; a is aleurone Fig. 20. from the seed of the vetch, b firom the castor bean, c from flax-seed, d from the fruit of the bayberry, (Myrica 106 b \,. .Fig. 18. THE VOLATILE PART OF PLANTS. cerifera,) and e from mace, (an appendage to the nutmeg, or fruit of the Myristica moschata.) Crystalloid aleurone.-It has been already remarked that crystallized albuminoids may be obtained from the blood of animals. It is equally true that bodies of similar character exist in plants, as was first observed by HIartig, (Entwickelungsgeschichte des P1anzenkeims, p. 104.) In form they sometimes imitate crystals quite perfectly, Fig. 21, a; in other cases, b, they are rounded masses, having some crystalline planes or facets. They are soft, yield easily to pressure, swell up to double their bulk when Fig. 21. soaked in weak acids or alkalies, and their angles have none of the constancy peculiar to proper crystals. Therefore the term crystalloid, i. e. having the likeness of crystals, is more appropriate than crystallized. As Cohn first noticed, (J,our. far Prakt. Chem., 80, p. 129,) crystalloid aleurone may be observed in the outer portions of the potato tuber, in which it invariably presents a cubical form. It is best found by examining the cells that adhere to the rind of a potato that has been boiled. In Fig. 21, a represents a cell from a boiled potato, in the centre of which is seen the cube of aleurone. It is surrounded by the exfoliated remnants of starchgrains. In the same figure, b exhibits the contents of a cell from the seed of the bur reed, (Sparganium ramosum,) a plant that is common along the borders of ponds. In the center is a comparatively large mass of aleurone, having crystalloid facets. 107 a I HOW CROPS GROW. According to Maschke, (Jour. fur Pr. Ch., 79, p. 148,) thle crystalloid aleurone that is abundant in the Brazil nut, is a compound of casein with some acid of unknown composition. This aleurone may be dissolved in water, and recovered in its original form on evaporation. Kubel's analysis of aleurone, prepared firom the Brazil nut by Hartig, gave its content of nitrogen 9.46 per cent. Aleurone from the yellow lupin yielded him 9.26 per cent. Since pure casein has 16 to 18 per cent of nitrogen, the aleurone contained about 52 to 59 per cent of albuminoids. Estimation of the Albuminoids.-The quantitative separation of these bodies is a matter of great difficulty and uncertainty. For most purposes their collective quantity in any organic substance may be calculated with sufficient accuracy from its content of nitrogen. All the albuminoids contain, on the average, about 16per cent of nitrogen. This divided into 100 gives a quotient of 6.25. If, now, the percentage of nitrogen that exists in a given plant be multiplied by 6.25, the product will represent its percentag,e of albuminoids, it being assumed that all the nitrogen of the plant exists in this form, which in most cases is practically true. Fruihling and Grouven have recently investigated the condition of the nitrogen of various plants, and have found that nitric acid, (N, O.,) which in the form of nitrate of potash has long been known to occur in vegetation, is present in but trifling quantity in most agricultural plants. In mature clover, esparsette, lucern, wheat, rye, oats, barley, the pea, and the lentil, it did not exceed 2 parts in 10,000 of the air-dry plant. In maize, they found twice this quantity; in beet and potato tops alone of all the plants examined was nitric acid present to the amount of fourtenths of one per cent, (Fs. St'., IX, 153.) Salts of ammnonia (N H3) likewise often exist in plants, but as a rule in quite inconsiderable quantities. 108 THE VOLATILE PArT OF PLANTS. AVERAGE QUANTITY OF ALBUMINOIDS IN VARIOUS VEGETABLE PRODUCTS. per cent. Maize fodder, green....................... 1.2 Beet tops ".................... 1.9 Carrot tops "....................3.5 Meadow grass "....................... 3.1 Red clover "....................... 3.7 White clover "....................4.0 Turnips, fresh............................ 1.0 Carrots "............................. 1.3 Potatoes "............................. 2.0 Corn cobs, air-dry......................... 1.4 Straw of summer grain, air-d ry............ 2.6 Straw of winter " "............ 3.0 Pea straw "............ 7.3 Bean straw "...........10.2 Meadow hay............. 8.5 Red clover hay *............13.4 White clover hay "...........14.9 Buckwheat kernel "............ 7.8 Barley "'............10.0 Maize "............10.7 Rye I" "............11.0 Oat " "............ 12.0 Wheat " "............13.2 Pea " "............ 22.4 Bean " ".............24.1 Lupine "'............34.5 APPENDIX TO ~ 4. CHLOROPIIYLL: TANNIN: A.LK,OIDS. Before dismissing the subject of the Proximate Elements of plants, we must notice several other substances of subordinate agricultural interest. Two of these, viz., (Chlorophyll and Tannin, though not figuring in the analysis of agricultural plants, are nevertheless of almost universal occurrence in all forms of vegetation, though usually in very minute quantity. Chlorophyll, i. e. leaf-green, is the name applied to the substance which occasions the green color in vegetation. It is found in all the surface of annual plants and of the annually renewed parts of perennial plants. It might readily be supposed that it constitutes a large portion of the leaves of vegetation, but the fact is quite otherwise. The green 109 Ho. HOW CROPS GROW. parts of plants usually contain chlorophyll only at their surface, ana in quantity no greater than colored fabrics contain the particles of dye. Chlorophyll being soluble in ether, accompanies fat or wax when these are removed from green vegetable matters by this solvent. It is soluble in chlorhydric and sulphuric acids, imparting to these liquids its intense green color. According to Pfaundler, the (impure?) chlorophyll of grass has the following percentage composition: Carbon 60.85 Hydrogen 6.39 Oxygen 32.78 Fremy has shown that chlorophyll may be easily decomposed into two coloring matters, a yellow, Zanthophyll, and a blue, Cyanophyll. This is accomplished by treating chlorophyll with a mixture of chlorhydric a(id and ether; the cyanophyll dissolves in the latter, and the zanthophyll is taken up by the former solvent. The yellow color of autumn leaves is perhaps due to zanthophyll. According to Sachs, there exists in those parts of plants, which, though not green, are capable of becoming so, a colorless substance, Leucophyll, which, in contact with oxygen, acquires a green color, being converted into chlorophyll. Tannin is the general designation of the bitter, astringent principles, (used in leather-making,) of the bark and leaves of the hemlock, oak, sumach, plum, pear, and many other trees, of tea, coffee, and of gall-nuts. It is found in small quantity in the young bean plant, and in many germinating seeds. Tannin is closely related to the carbohydrates, as is demonstrated alike by the microscopic study of its development in the plant, and by our knowledge of its chemical composition. The tannins are weak acids, and are distinguished, according to their origin, as Gallotannic acid (from nut-galls), Caffeotannic acid (from coffee), Quercitannic acid (from the oak), etc. As already hinted, the tannins are Glucosides, or compounds of sugar, with some other substance. In gall-tannin the sugar is glucose; and the substance associated with, or rather yielded by it on decomposition, is known as Gallic acid. By boiling gall-tannin with a dilute acid, or by subjecting its solution to fermentation, decomposition into the two substances named is accomplished. According to Strecker, the composition of gall-tannin and this conversion are indicated by the following formula: Tannin. Water. Gallic acid. Glucose. 2 (C27 H22 017) + 8 (H2 0) = 6 (C7 He 06) + C12 H24 012 THE ALXmLOIDS are a class of bodies very numerous in poisonous and medicinal plants, of which they usually constitute the active principle. Those which have an agricultural interest are Nicotin, Caffein, and Theobromin. Nicotin, C10 H14 N2, is the narcotic and extremely poisonous principle in tobacco, where it exists in combination with malic and citric 110 THE ASH OF PLANTS. acids. In the pure state it is a colorless, oily liquid, having the odor of tobacco in an extreme degree. It is inflammable and volatile, and so deadly that a single drop will kill a large dog. French tobacco contains 7or 8 p. c.; Virginia, 6 or 7 p. c.; and Maryland and Havanna, about 2p. c. of nicotin. Nicotin contains 17.3 p. c. of nitrogen, but no oxygen. Caffein, C8 H110 N4 02, exists in coffee and tea combined with tannic acid. In the pure state it forms white, silky, fibrous crystals, and has a bitter taste. In coffee it is found to the extent of one-half per cent; in tea it occurs in much larger quantity, sometimes as high as 6 per cent. T'heobroinin, C7 HI8 N4 02, resembles caffein in its characters, and is closely related to it in chemical composition. It is found in the cacao-bean, from which chocolate is manufactured. The alkaloids are remarkable from containing nitrogen, and from having strongly basic characters. They derive their designation, alkaloids, from their likeness to the alkalies. CHAPTER IL THE ASH OF PLANTS. ~ 1. THE INGREDIENTS OF THE ASH. As has been stated, the volatile or destructible part of plants, i.e. the part which is converted into gases or vapors under the ordinary conditions of burning, consists chiefly of Carbon, iydrogen, Oxygen, and Nitrogen, together with minute quantities of Sulphur and Phosphorus. These elements, and such of their compounds as are of general occurrence in agricultural plants, viz., the Organic Proximate Principles, have been already described in detaiL The non-volatile part or ash of plants also contains, or may contain, Carbon, Oxygen, Sulphur, and Phosphorus. It is, however, in general, chiefly made up of eight other elements, whose common compounds are fixed at the ordinary heat of burning. iii o I IOW CROPS GROWV. In the subjoined table, the names of the 12 elements of the ash of plants are given, and they are grouped under two heads, the non-metals and the metals, by reason of an important distinction in their chemical nature. ELEIMENTS OF THE ASHI OF PLANTS. Non-Metals. Metals. Oxygen Potassium Carbon Sodium Sulphur Calcium Phosphorus Magnesium Silicon Iron Chlorine Manganese If to the above be added Hydrogen and Nitrogen the list includes all the elementary substances that belong to agricultural vegetation. Hydrogen is never an ingredient of the perfectly burned and dry ash of any plant. Nitrogen may remain in theash under certain conditions in the form of a Cyanide, (compound of Carbon and Nitrogen,) as will be noticed hereafter. Besides the above, certain other elements are found, either occasionally in common plants, or in some particular kind of vegetation: these are Iodine, Bromine, Fluorine, Titanium, Arsenic, Lithium, Rubidium, Barium, Aluminum, Zinc, Copper. We may now complete our study of the Composition of the Plant by attending to a description of tiose elements that are peculiar to the ash, and of those compounds which may occur in it. It will be convenient also to describe in this section some substances, which, although not ingredients of the ash, may exist in the plant, or are otherwise important to be considered. The non-metallic elements, which we shall first no. tice, though differing more or less widely among themselves, have one point of resemblance, viz., they and their compounds with each other have acid properties, i. e. they 112 THE ASHII OF PLANTS. either are acids in the ordinary sense of being sour to the taste, or enact the part of acids by uniting to metals or metallic oxides, to form salts. We may, therefore, designate them as the acid elements. They are Oxygen, Sulphur, Phosphorus, Carbon, Silicon, and Chlorine. (Less common are Arsenic, Titanium, Iodine, Bromine, and Fluorine.) With the exception of Silicon, (and Titanium,) and the denser forms of Carbon, these elements by themselves are readily volatile. Their compounds with each other, which may occur in vegetation, are also volatile, with two exceptions, viz., Silicic and Phosphoric acids. In order that they may resist the high temperature at which ashes are formed, they must be combined with the metallic elements or their oxides as salts. Oxygen, Symbol 0, atomic weight 16, is an ingredient of the ash, since it unites with nearly all the other elements of vegetation, either during the life of the plant, or in the act of combustion. It unites with Carbon, Sulphur, Phosphorus, and Silicon, forming acid bodies; while with the metals it produces oxides, which have the characters of bases. Chlorine alone of the elements of the plant does not unite with oxygen, either in the living plant, or during its combustion. CARLON AND ITS COMPOUNDS. Carbon, Sym. C, at. wt. 12, has been noticed already with sufficient fulness, (p. 31.) It is often contained as charcoal in the ashes of the plant, owing to its being enveloped in a coating of fused saline matters, which shield it from the action of oxygen. Carbonic acid, Sym. C 0O, molectuar weight, 44, is the colorless gas which causes the sparkling or effervescence of beer and soda water, and the frothing of yeast. It is formed by the oxidation of carbon, when vegetable matter is burned, (Exp. 6.) It is, therefore, found in the aEh of plants, combined with those bases which in the liv 113 HOW CROPS GROW. ing organism existed in union with organic acids; the lat ter being destroyed by burning. It also occurs in combination with.lime in the tissues of many plants. Its compounds with bases are carbonates to be noticed presently. When a carbonate, as marble or limestone, is drenched with a strong acid, like vinegar or muriatic acid, the carbonic acid is set free with effer vescence. Cyanogeii, Syn. CN.-This important compound of Carbon and Nitrogen is a gas which has an odor resembling that of peach-pits, and which burns on contact with a lighted taper with a fine purl)le flame. In its union with oxygen by combustion, carbonic acid is formed, and nitrogen set free, CN + 20 = CO2 + N. Cyanogen may be prepared by heating an intimate mixture of two parts by weight of ferrocyanide of potassium, (yellow prussiate of potash,) and three parts of corrosive sublimate. The operation may be conducted in a test tube or small flask, to the mouth of which is fitted a cork penetrated by a narrow glass tube. On applying heat, the gas issues. and may be set on fire to observe its beautiful flame. Cyanogen, combined with iron, forms the Prussian blue of commerce, and its name, signifying the blue-produces, was given to it firom that circumstance. Cyanogen unites with the metallic elements, giving rise to a series of bodies which are termed Cyanides. Some of these often occur in small quantity in the ashes of plants, being produced in the act of burning by the union of nitrogen with carbon and a metal. For this result, the temperature must be very high, carbon must be in excess, the metal is usually potassium or calcium, the nitrogen may be either free nitrogen of the atmosphere or that originally existing in the organic matter. With hydrogen, cyanogen forms the deadly poison hydrocyanic or prussic acid, HI Cy, which is produced from amnygdaline, one of the ingredients of bitter almonds, peach, and cherry seeds, when these are crushed in contact with water. When a cyanide is brought in contact with steam at high temperatures, it is decomposed, all its nitrogen being converted into ammonia. Cyanogen is a normal ingredient of one common plant. The oil of mustard is the sulpho-cyanide of allyle, C3 H5 CNS. SULPHUR AND ITS COMPOUNDS. Sulphur, Sym. S, at. wt. 32.-The properties of this element have been already described, (p. 42.) Some of 114 THE ASH OF PLANTS. its compounds have also been briefly alluded to, I at require more detailed notice. Sulphydric Acid, Sym iH2 S, mo. wt. 34. This substance, familiarly known as sulphuretted hydrogen, occurs dissolved in the water of numerous so-called sulphur springs, as those of Avon and Sharon, N. Y., from which it escapes as a fetid gas. It is not unfrequently emitted firom volcanoes and fumaroles. It is likewise produced in the decay of organic bodies which contain sulphur, especially eggs, the intolerable odor of which, when rotten, is largely due to this gas. It is evolved from manure heaps, from salt marshes, and even from the soil of moist meadows. The ashes of plants sometimes yield this gas when they are moistened with water. In such cases, a sulphide of potassium or calcinum has been formed in small quantity during the incineration. Sulphydric acid is set free in the gaseous form by the action of an acid on various sulphides, as those of iron, (Exp. 17,) antimony, etc., as well as by thie action of water dn the sulphides of the alkali and alkali-earth metals. It may be also generated by passing hydrogen gas into melted sulphur. Sulphuretted hydrogenhas a slight acid taste. It is highly poisonous and destructive, both to animals and plants. Sulphiarous Acid, Sym. SO2, mo. wt. 64. When sulphur is burned in the air, or in oxygen gas, it forms copious white suffocating fumes, which consist of one atom of sulphur, united to two atoms of oxygen; S 02, (Exp. 15.) Sulphurous acid is characterized by its power of discharging, for a time at least, most of the red and blue vegetable colors. It has, however, no action on many yellow colors. Straw and wool are bleached by it in the arts. Sulphurous acid is emitted from volcanoes, and from fissures in the soil of volcanic regions. It is produced when bodies containing sulphur are burned with imperfect access of air, and is thrown into the atmosphere in large quantities from fires which are fed by mineral coal, as well as from the numerous roasting heaps of certain metallic ores, (sulphides,) which are wrought in mining regions. Sulphurous acid may unite with bases, yielding salts known as subphites, some of which, viz., sulphite of lime and sulphite of soda, are employed to check or prevent fermentation, an effect also produced by the acid itself Anhydrous* Sulphuric Acid, Sym. SO,, mo. wt. 80, is known to the chemist as a white, silky solid, which attracts moisture with great avidity, and, when thrown into water, hisses like a hot iron, forming the hydrated sulphuric acid. s i. e., free from water. 115 HOW CROPS GROW. Hydrated Sulphuric Acid, Symn. Ha O S03 or H,2 SO,04, mo. wt. 98-the sulphuric acid of commerce-is a substance of the highest importance, its manufacture being the basis of the chemical arts. In its concentrated form it is known as oil of vitriol, and is a colorless, heavy liquid, of an oily consistency, and sharp, sour taste. It is manufactured on the large scale by mingling sulphurous acid gas, nitric acid gas, and steam, in large leadlined chambers, the floors of which are covered with water. The sulphurous acid takes up oxygen from the nitric acid, and the sulphuric acid thus formed dissolves in the water, and is afterwards boiled down to the proper strength in glass vessels. The chief agricultural application of commercial sulphuric acid is in the preparation of "superphosphate of lime," which is consumed as a fertilizer in immense quantities. This is made by mixing together dilute sulphuric acid with bone-dust, bone-ash, or some mineral phosphate. Sulphuric acid occurs in the free state, though extremely dilute, in certain natural waters, as in the Oak Orchard Acid Spring of Orleans, N. Y., where it is produced by the oxidation of sulphide of iron. Sutlphuric acid is very corrosive and destructive to most vegetable and animal matters. Exp. 53.-Stir a little oil of vitriol with a pine stick. The wood is immediately browned or blackened, and a portion of it dissolves in the acid, communicating a dark color to the latter. The commercial acid is often brown from contact with straws and chips. Strong sulphuric acid produces great heat when mixed with water, as is done for making superphosphate. ExP. 51.-Place in a thin glass vessel, as a beaker glass, 30 c. c. of water; into this pour in a fine stream 120 grams of oil of vitriol, stirring all the while with a narrow test tube, containing a teaspoonful of water. If the acid be of full strength, so much heat is thus generated as to boil the water in the stirring tube. In mixing oil of vitriol and water, the acid should always be slowly poured into the water, with stirring, as above directed. When water is added to the acid, it floats upon the latter, or mixes with it but super 116 THE ASH OF PLANTS. ficially, and the liquids may be thrown about by the sudden.)rmatioa of steam at the points of contact, when subsequently stirred. Sulphuric acid forms with tlhe bases an important class of salts-the sulphates-to be presently noticed, some of which exist in the ash, as well as in the sap of plants. When organic matters containing sulphur, as hair, albumin, etc., are burned with full access of air, this element remains in the ash as sulphates, or is partially dissipated as sulphurous acids PHOSPHORUS AND ITS COMPOUNDS. Phosphorus, Sym. P, at. wt. 31, has been sufficiently described, (p. 43.) Of its numerous compounds but two require additional notice. Anhydrous Phosphoric Acid, Sym. P, 05, mo. wt. 142, does not occur as such in nature. When phosphorus is burned in dry air or oxygen, anhydrous phosphoric acid is the snow-like product, (Exp. 18.) It has no sensible acid properties until it has united to water, which it combines with so energetically as to produce a hissing noise from the heat developed. On boiling it with water for some time, it completely dissolves, and the solution contains Hydrated Phosphoric Acid, Sym. P, O5, 3 H2 O0, 196, or H13 PO4, 98.-The chief interest which this compound has for the agriculturist lies in the fact that the combinations which are formed between it and various bases -phosphates-are among the most important ingredients of plants and their ashes. When bodies containing phosphorus in other forms than phosphoric acid, as protagon, (p. 93,) and, perhaps, some of the albuminoids, are disorganized by heat or decay the phosphorus appears in the ashes or residue, in the condition of phosphoric acid or phosphates. The formation of several phosphates has been shown in 117 HOW CROPS GROW. Exp. 20. Further account of them will be given under the metals. CHLORINE AND ITS COMPOUNDS. Chlorine, Sym. Cl, at. wt. 35.5.-This element exists in the free state as a greenish-yellow, suffocating gas, which has a peculiar odor, and the property of bleaching vegetable colors. It is endowed with the most vigorous affinities for many other elements, and hence is never met with, naturally, in the free state. Sprengel claims to have found that Glaux maaritima and Salicornia herbacea, plants growing in salt marshes, exhale chlorine. He says that the chlorine thus evolved is very quickly converted into chlorhydric acid, by acting on the vapor of water which exists in the atmosphere. Such an exhalation of chlorine is manifestly impossible. The gas, were it eliminated within the plant, would be consumed before it could escape into the atmosphere. Chlorhydric acid is evolved from the mud of salt marshes when left bare by ebb of the tide, and exposed to the heat of the summer sun. It comes from the mutual decomposition of chloride of magnesium and water, Mg C12 + H20 = MgO + 2HC1. Exp. 55.-Chlorine may be prepared by heating a mixture of chlorhydric acid and black oxide of manganese or red-lead. The gas being nearly five times as heavy as common air, may be collected in glass bottles by passing the tube which delivers it to the bottom of the receiving vessel. Care must be taken not to inhale it, as it energetically attacks the interior of the breathing passages, producing the disagreeable symptoms of a cold. Chlorine dissolves in water, forming a yellow solution. Very weak chlorine water was found by Humboldt to facilitate the sprouting of seeds. In some form of combination chlorine is distributed over the whole earth, and is never absent from the plant. The compounds of chlorine are termed chlorides, and may be prepared, in most cases, by simply putting their elements in contact, at ordinary or slightly elevated temperatures. Clihlorhydric acid, also hdrochloric acid, Sym. H Cl, m?no. wt. 36.5.-When Chlorine and Hydrogen gases are mingled together, they slowly combine if exposed to diffused light; but if placed in the sunshine, they unite explosively, and chloride of hydrogen or chlorhydric 1.18 THE ASH OF PLANTS. acid is formed. This compound is a gas that dissolves with great avidity in water, forming a liquid which has a sharp, sour taste, and possesses all the characters of an acid. The muriatic acid of the apothecary is water holding in solution several hundred times its bulk of chlorhfiydric acid gas, and is prepared from common salt, whence its ancient name spirits of salt. Chlorhydric acid is the usual source of chlorine gas. The latter is evolved from a heated mixture of this acid with peroxide of manganese. In this reaction the hydrogen of the chlorhydric acid unites with the oxygen of the peroxide of manganese, producing water, while chloride of manganese and free chlorine are separated. 4 H C1 + Mn 2 = Mn C12 + 2 H20 + 2 C1. When chlorine dissolved in water, is exposed to the sun-light, there ensues a change the reverse of that just noticed. Water is decomposed, its oxygen is set free, and chlorhliydric acid is formed, H20 + 2C1 = 2HC1 + O. This reaction probably takes place when the germination of seeds is hastened by chlorine. The oxygen thus liberated is doubtless the real agent which excites growth in the sleeping germ. The two reactions just noticed are instructive examples of the different play of affinities between several elements under unlike circumstances. Chlorhydric acid, being volatile, does not occur in the ashes of plants, nor probably in the plant itself, unless, as may possibly happen, it is formed in, and exhales from the vegetation, as it sometimes does from the mud of salt marshes, (p. 118.) Chlorhlydric gas is found in volcanic emanations. This acid is a ready means of converting various metals or metallic oxides into chlorides, and its solution in water is a valuable solvent and reagent for the purposes of the chemist. Iodine, Sym. I, at. wt. 127.-This interesting body is a black solid at ordinary temperatures, having an odor resembling that of chlorine. Gently heated, it is converted into a violet vapor. It occurs in sea-weeds, and is obtained from their ashes. It gives with starch a blue or purple compound, and is hence employed as a test for that substance, (p. 64.) It is analogous to chlorine in its chemical relations. It is not known to ..occur in sensible quantity in agricultural plants, although it may well exist in the grasses of salt-bogs, and in the produce of soils which are manaured with sea-weed. Bi-omine and Fluorine may also exist in very small quantity in plants, but these elements require no further notice in this treatise. SILICON AND ITS COMPOUNDS. Silicon, Sym. Si, at. wt. 28.-This element, in the free state, is only known to the chemist. It may be prepared 119 HOW CROPS GROW. in three modifications: one, a brown, powdery substance; another, resembling black-lead, (p. 31,) and a third, that occurs in crystals, having the form and nearly the hardness of the diamond. Anhydrous Silicic Acid, Sym. Si ~2, mo. wt. 60.-This compound, known also as Silica, and anciently termed &ilex, is widely diffused in nature, and occurs to an enormous extent in rocks and soils, both in the free state and in combination with other bodies. Free silica exists in nearly all soils, and in many rocks, especially in sandstones and granites, in the form known to mineralogists as quartz. The glassy, white or transparent, often yellowish or red fragments of common sand, which are hard enough to scratch glass, are almost invariably this mineral. In the purest state, it is rock-crystal. Jasper, flint, and agate, are somewhat less pure silica. Silicates.-Anhlydi'ous silicic acid is extremely insoluble in pure water and in most acids. It has, therefore, none of the sensible qualities of acids, but is nevertheless capable of union with bases. It is slowly dissolved by strong, and especially by hot solutions of potash and soda, forming soluble silicates of these alkalies. Exp. 56.-Fo-ornation of silicate of potash. Heat a piece of quartz or flint, as large as a chestnut, as hot as possible in the fire, and quench suddenly in cold water. Reduce it to fine powder in a porcelain mortar, and boil it in a porcelain dish with twice its weight of caustic potash, and eight or ten times as much water, for two hours, taking care to supply the water as it evaporates. Pour off the whole into a tall narrow bottle, and leave at rest until tlhe undissolved silica has settled. The clear liquid is a basic silicate of potash, i. e. a silicate which contains a number of molecules of base for each molecule of silica. It has, in fiact, the taste and feel of potash solution. The so-called water-glass, now enmployed in the arts, is a similar silicate of potash or soda. When silica is strongly heated with potash or soda, or with limte, magnesia, or oxide of iron, it readily melts together and unites with these bodies, though nearly infusible by itself, and silicates are the result. The silicates thus formed with potash and soda are soluble in water, like 120 THE ASH OF PLANTS. the product of ]ixp. 56, when the alkali exceeds a certain proportion-when highly basic; but with silica in excess, (acid silicates,) they dissolve with difficulty. A mixed silicate of alkali and lime, alumina, or iron, with a large proportion of silica, is nearly or altogether insoluble, not only in water, but in most acids-constitutes, in fact, ordinary glass. A multitude of silicates exist in nature as rocks and minerals. Ordinary clay, common slate, soapstone, mica, or mineral isinglass, feldspar, hornblende, gailnet, and other compounds of fiequent and abundant occurrence, are silicates. The natural silicates are of two classes, viz., the acid silicates, (containing a preponderance of silica,) and basic silicates, (with large prolportion of base): the former are but slowly dissolved or decomposed by acids, while the latter are readily attacked even by carbonic acid. Many native silicates are anAydrous, or destitute of water; others are hydrous, i. e. they contain water as a large and essential ingredient. Hydrated Silica.-Various compounds of silica with water are known to the chemist. Of these but three need be mentioned here. Soluble Silica.-This body, doubtless a hydrate, is known only in a state of solution. It is formed when the solution of an alkali-silicate is decomposed by means of a large excess of some strong acid, like the chlorhydric or sulphuric. ExP. 57.-Dilute half the solution of silicate of potash obtained in Exp. 56 with ten times its volume of water, and add diluted chlorhydric acid gradually until the liquid tastes sour. In this Exp. the chlorhydric acid decomposes and destroys the silicate of potash, uniting itself with the base with production of chloride of potassium, which dissolves in the water present. The silica thus liberated unites chemically with water, and remains also in solution. By appropriate methods Doveri and Graham have removed from solutions like that of the last Exp). everything but the silica, and obtained solutions of silica in pure water. Graham prepared a liquid that gave, when evaDorat 6 121 HOW CROPS GROW. ed and aeated, 14 per cent of anhydroum silica. This so lution was clear, colorless, and not viscid. It reddened litmus paper like an acid. Though not sour to the taste, it produced a peculiar feeling on the tongue. Evaporated to dryness at a low temperature, it left a transparent, glassy mass, which had the composition Si 0,, HO20. This dry residue was insoluble in water. These solutions of silica in pure water are incapable of existing for a long time without suffering a remarkable change. Even when protected from all external agencies, they sooner or later, usually in a few days or weeks, lose their fluidity and transparency, and coagulate to a stiff jelly, firom the separation of a nearly insoluble hydrate of silica, which we shall designate as gelatinous silica. The addition of -f- of an alkali or earthy carbonate, or of a few bubbles of carbonic acid gas to the strong solutions, occasions their immediate gelatinization. A minute quantity of potash or soda, or excess of chlorhydric acid, prevents their coagulation. Gelatinous Silica.-This substance, which results from the coagulation of the soluble silica just described, usually appears also when the strong solution of a silicate has strong chlorhydric acid added to it, or when a silicate is decomposed by direct treatment with a concentrated acid. It is a white, opaline, or transparent jelly, which, on drying in the air, becomes a fine, white powder, or forms transparent grains. This powder, if dried at ordinary temperatures, is 3 Si 0,, 2 H20. At the temperature of 212~ F., it loses half its water. At a red heat it becomes anhydrous. Gelatinous silica is distinctly, though very slightly, soluble in water. Fuchs and Bresser have found by experiment that 100,000 parts of water dissolve 13 to 14 parts of gelatinous silica. TDe hydrates of silica which have been subjected to a 122 I i. t ".:4 IIK. I';. I I.. Ic I I THE ASH OF PLANTS. heat of 2120 or more, appear to be totally insoluble in p- re water. All the hydrates of silica are readily soluble inI soluti(ons of the alkalies and alkali carbonates, and readily unite with moist, slaked lime, forming silicates. ExP. 58.-Gelatinous Silica.-Pour a small portion of the solution of silicate of potash of Exp. 56, into strong chlorhydric acid. Gelatinous silica separates and falls to the bottom, or the whole liquid becomes a trausparent jelly. ExP. 59.-Conver-sion of soluble i~to ixisolubre hydrated silica.-Evaporate the solution of silica of Exp. 57, which contains free chlorhydric acid, in a porcelain dish. As it becomes concentrated, it is very likely to gelatinize, as happened in Exp. 58, on account of the removal of the solvent. Evaporate to perfect dryness, finally on a water-bath (i.e. on a vessel of boiling water which is covered by the dish containing the solution). Add to the residue water, which dissolves away the chloride of potassium, and leaves insoluble hydrated silica, 3 Si 02, H20, as a gritty powder. In the ash of plants, silica is usually found in combination with alkalies or lime, owing to the high temperature to which it has been subjected. In the plant, however, it exists chiefly, if not entiuely, in the free state. Titanium, an element which has many analogies with silicon, though rarely occurring in large quantities, is yet often present in the form ot Titanic acid, Ti O2, in rocks and soils, and according to Salm Horstmar may exist in the ashes of barley and oats. Arsenic, in minute quantity, has been found by Davy in turnips which had been manured with a fertilizer (superphlosphate), in whose preparation, oil of vitriol, containing this substance, was employed. The metallic elements which remain to be noticed, viz.: Potassium, Sodium, Calcium, Magnesiutm, Iron, Manganese, (Lithium, Rubidium, Caesium, Aluminum, Zinc, and Copper,) are basic in their character, i. e., they unite with the acid bodies that have just been described to produce salts. Each one is, in this sense, the base of a series of saline compounds. ALKALI-METATLS.-The elements Potassium, Sodium, (Lithium, Rubidium, and Caesium), are termel alkali, I t'3 HOW CROPS GROW. metals. Their oxides are very soluble in watter, and are called alkalies. The metals themselves do not occur in nature, and can only be prepared by tedious chemical processes. They are silvery-white bodies, and are lighyter than water. Exposed to the air, they quickly tarnish from the absorption of oxygen, and are rapidly converted into the corresponding alkalies. Thrown upon water, they mostly inflame and burn with great violence, decomposing the liquid, Exp. 11. Of the alkali-metals, Potassium is invariably found in all plants. Sodium is especially abundant in marine and strand vegetation; it is generally found in agricultural plants, but is occasionally absent from them. POTASSIUM AND ITS COMPOUNDS. Potassium, symn. K;* at. wt. 39.-When heated in the air, this, metal burns with a beautiful violet light, and forms potash. Potash, K20, 94, is the alkali, and base of the potash salts. Hydrate of Potash K20, H20, 112, or K H 0, 56, is the caustic potash of the apothecary and chemist. It may be procured in white, opaque masses or sticks, which rapidly absorb moisture and carbonic acid from the air, and readily dissolve in water, forming potash-lye. It strongly corrodes many vegetable and most animal matters, and dissolves fats, forming potash-soaps. It unites with acids like K20, water being set free. SODI1UM AND ITS COMPOUNDS. Sodium, Na,t 23.-Burns with a brilliant, orange-yellow flame. * From the Latin name Kalium. + Prom the Latin name _~atriunL 124 THE ASH OF PLANTS. Soda, Na2O, 62.-This alkali, the base of the soda salts, is not distinguishable firom potash by its sensible properties. Hydrate of Soda, or Caustic Soda, Na2O, HO0, 80, or Na H 0, 40.-This body is like caustic potash in appearance and general characters. It forms soaps with the various fats. While the potash-soaps are usually soft, those made with soda are commonly hard. LITIIIUM: RUBIDIUM: CAESIUM. Lithium, Li, 7.-The compounds of this metal are of much rarer occurrence than those of Potassium and Sodium. The element itself is the lightest metal known, being but little more than half as heavy as water. It burns with a vivid white light when heated in the air. Lithia, Li20, 30, and its Hydrate, closely resemble the corresponding compounds of the two elements above described. They yield by union with acids the lithia-salts. Rubidium, Rb, 85.5, and Caesium, Cs, 133.-Besides Potassium, Sodium, and Lithium, there are two other recently discovered alkali-metals, viz.: Rubidium and Caesium. These elements are comparatively rare, although they appear to be widely distributed in nature in minute quantity. Rubidium has been found in the ashes of tobacco and sugar-beet, as well as in commercial potash. Caesium, which is the rarer of the two, has as yet not been detected in the ashes of plants, but undoubtedly occurs in them. These metals and their compounds have, in general, the closest similarity to the other alkali-metals. ALKALI-EARTH METALS.- The two metallic elements next to be noticed, viz.: Calcium and Magnesium, give, with oxygen, the alkali-earths, lime and magnesia. The metals are only procurable by difficult chemical processes, and from their eminent oxidability are not found in nature. They are but a little heavier than water. Their oxides are but slightly soluble in water. CALCIUM AND ITS COMPOUNDS. Calcium, Ca, 40, is a brilliant ductile metal having a light yellow color. In moist air it rapidly tarnishes and acquires a coating of lime. ~ 125 HOW CROPS GROW. Lime, CaO, 56.-Is the result of the oxidation of cal. cium. It is prepared for use in the arts by subjecting limestone or oyster-shells to an intense heat, and usually retains the form and much of the hardness of the material fi'om which it is made. It has the bitter taste and corroding properties of the alkalies, though in a less degree. It is often called quick-lime, to distinguish it from its compound with water. It may occur in the ashes of plants when they have been maintained at a high heat after the volatile matter has been burned away. It is the base of the salts of lime. Hydrate of Lime, CaO, H1O, or CaH2 O2, 74.-Quicklime, when exposed to the air, gradually absorbs water and falls to a fine powder. It is then said to be air-slaked. When water is poured upon quick-lime it penetrates the pores of the latter, and shortly the falling to powder of the lime and the development of much heat, give evidence of chemical union between the lime and the water. This chemical combination is further proved by the increase of weight of the lime, 56 lbs. of quick-lime becoming 74 lbs. by water-slaking. On heating slaked lime to redness, its water may be expelled. When lime is agitated for some time with much water, and the mixture is allowed to settle, the clear liquid is found to contain a small amount of lime in solution (one part of lime to 700 parts of water). This liquid is called lime-water, and has already been noticed as a test for carbonic acid. Lime-water has the alkaline taste in a marked degree. MAGNESIJUM A-D ITS COMPOUNDS. Magnesium, MIg, 24-Metallic magnesium has a silverwhite color. When heated in the air it burns with extreme brilliancy (magnesium light), and is c(nverted into magnesia 0, 126 THE ASH OF PLANTS. Magnesia, Mg 0, 40, is the oxide of magnesium. It is found in the drug-stores in the shape of a bulky white powder, under the name of calcined magnesia. It is prepared by subjecting either hydrate, carbonate, or nitrate, of magnesia to a strong heat. It occurs in the ashes of plants. Hydrate of Magnesia, Mg O HO0, is produced slowly and without heat, when magnesia is mixed with water. It occurs as a transparent, glassy mineral (Brutcite) at Texas, Penn., and a few other places. It readily absorbs carbonic acid, and passes into carbonate of magnesia. Hydrate of magnesia is so slightly soluble in water as to be tasteless ft requires 55,000 times its weight of water for solution, (Fresenius). HEAvY MIETALS.-The two metals remaining to notice are Iron and Manganese. These again considerably resemble each other, though they differ exceedingly from the metals of the alkalies and alkali-earths. They are about eight times heavier than water. Each of these metals forms two basic oxidles, which are totally insoluble in pure Wter. IRON AND ITS COMPOUNDS. Iron, Fe,* 56.-The properties of metallic iron are so well known that we need not occupy any space in recapitulating them. Protoxide t of Iron, Fe 0, 72.-When sulphuric acid in a diluted state is put in contact with metallic iron, hydrogen gas shortly begins to escape in bubbles from the liquid, and the iron dissolves, uniting with the acid to form the protosulphate f of iron, the salt known commonly as copperas or green-vitriol. *From the Latin name Ferrum. t The prefix prot or proto, from the Greek, meaning first, is employed to ditinguish this oxide and its salts from the compounds to be subsequently de scribed. 127 HOW CROPS GROW; H20, SO, + Fe=FeO, SO + H. If, now, lime-water or potash-lye be added to the s(,l a. tion of iron thus obtained, a white or greenish-white precipitate separates, which is a hydrated protoxide of iron, (Fe 0,2 11H0). This precipitate rapidly absorbs oxygen from the air, becoming black and finally brown. The anhydrous protoxide of iron is black. Carbonate of protQxide of iron is of frequent occurrence as a mineral (spathic iron), and exists dissolved in many mineral waters, especially in the so-called chalybeates. Sesquioxide of Iron,* Fe2 O3, 160.-When protoxide of iron is exposed to the air, it acquires a brown color from union with more oxygen, and becomes hydrated sesquioxide. The yellow or brown rust which forms on surfaces of metallic iron when exposed to moist air is the same body. Iron in the form of sesquioxide is found in the ashes of all agricultural plants, the other oxides of iron passing into this when exposed to air at high temperatures. It is found in immense beds in the earth, and is an important ore, (specular iron, h.ematite). It dissolves in acids, forming sesquisalts of iron, which have a yellow color. MAGNETIC OXIDE OF IRON, Fe3 04, or FcO, Fes 03, is a combination of the two oxides above mentioned. It is black, and is strongly attracted by the magnet. It constitutes, in fact, the native magnet, or loadstone, and is a valuable ore of iron. MANGANESE AND ITS COMPOUNDS. Manganese, Mn, 55.-Metallic manganese is difficult to procure in the free state, and much resembles iron. Its oxides which concern the agriculturist are analogous to those of iron just noticed. Protoxide of Manganese, Mn 0, 71, has an olives green color. It is the base of all the usually ocecurring * The prefix sesqui (one and a half) is applied to those oxides in which the ratio of metal to oxygen is as one to one and a half, or, what is the sanme, as two to three. The above compound is also called peroxide of iron. 128 THE ASH OF PLANTS. salts of manganese. Its hydrate, prepared by decomposing protosulphate of manganese by lime-water, is a white substance, which, on exposure to the air, shortly becomes brown and finally black from absorption of oxygen. The salts of protoxide of manganese are mostly pale rose-red in color. Sesquioxide of Ilanganese, Mn2 0O, occurs native as the mineral braunite, or, combined with water, as manganite. It is a substance having a red or black-brown color. It dissolves in cold acids, forming salts of an intensely red color. These are, however, easily decomposed by heat, or by organic bodies, into oxygen and protosalts. PRed Oxide of Manganese, Mn3 04, or Mn 0, Mn2 03.-This oxide remains when manganese or any of its other oxides are subjected to a high temperature with access of air. The metal and the protoxide gain oxygen by this treatment, the higher oxides lose oxygen until this compound oxide is formed, which, as its symbol shows, corresponds to the magnetic oxide of iron. It is found in the ashes of plants. Black Oxide of Manganese, Mn O2.-This body is found extensively in nature. It is employed in the preparation of oxygen and chlorine, (bleaching powder), and is an article of commerce. Some other metals occur as oxides or salts in ashes, though not in such quantity or in such plants as to possess any agricultural significance in this respect. Alumina, the sesquioxide of the metal ALUMINUM, is found in considerable quantity (20 to 50 per cent) in the ashes of the ground pine (Lycopodium). It is united with an organic acid (tartaric, according to Berzelius; malic, according to Ritthausen) in the plant itself It is often found in small quantity in the ashes of agricultural plants, but whether an ingredient of the plant or due to particles of adhering clay is not in all cases clear. Zinc has been found in a variety of yellow violet that grows in the zinc mines of Aix la Chapelle. Copper is frequently present in minute quantity in the ash of trees, especially of such as grow in the vicinity of manufacturing establishments, where dilute solutions containing copper are thrown to waste. The salts or compounds of metals with non-metals found in the ashes of plants or in the unburned plant re main to be considered. Of the elements, acids, and oxides, that have been noticed as constituting the ash of plants, it must be remarked that with the exception of silica, magnesia, oxide of 6* 129 HOW CROPS GROW. iron, and oxide of manganese, they all exist in the ash in the form of salts, (compounds of acids and bases). In the living agricultural plant it is probable, that of them all, only silica occurs in the uncombined state. We shall notice in the first place the salts which may occur in the ash of plants, and shall consider them under the following heads, viz.: Carbonates, Sulphates, Phosphates, and Chlorides. As to the Silicates, it is unnecessary to add anything here to what has been already mentioned. TiE CARBONATES which occur in the ashes of plants ore those of Potash, Soda, and Lime. (Carbonate of Rubidia, similar to carbonate of soda, and Carbonate of Lithia, rather insoluble in water, may also be present, but in exceedingly minute quantity.) The Carbonates of Magnesia, Iron, and Manganese, are decomposed by the heat at which ashes are prepared. Carbonate of Potash, KO20 CO2, 114.-The pearl-ash of commerce is a tolerably pure form of this salt. When wood is burned, the potash which it contains is found in the ash, chiefly as carbonate. If wood-ashes are repeatedly washed or leached with water, all the salts soluble in this liquid are removed; by boiling this solution down to dryness, which is done in large iron pots, crude potash is obtained, as a dark or brown mass. This, when somewhat purified, yields pearl-ash. Carbonate of potash, when pure, is white, has a bitter, biting taste-the so-called alkaline taste. It has such attraction for water, that, when exposed to the air, it absorbs moisture and becomes a liquid. If chlorhydric acid be poured upon carbonate of potash a brisk effervescence immediately takes place, owing to the escape of carbonic acid gas, and chloride of potassium and water are formed which remain behind. K2O CO + 2H C1 = 2K C1 + H,O + CO0. Bicarbonate of Potash, KHO CO2.-A solution of 130 i THE ASH OF PLANTS. carbonate of potash when exposed to carbonic acid gas absorbs the latter, and the bicarbonate of potash is produced, so called because to a given amount of potassium it contains twice as much carbonic acid as the carbonate. Potash-saleratus consists essentially of this salt. It probably exists in the juices of various plants. Carbonate of Soda, Na2O CO2, 106.-This substance, so important in the arts, was formerly made from the ashes of certain marine plants (Salsola and Salicorznia), in a manner similar to that now employed in wooded countries for the preparation of potash. It is at present almost wholly obtained from common salt by a somewhat complicated process. It occurs in commerce in an impure state under the name of Soda-ash. When nearly pure it forms salsoda, which usually exists in transparent crystals or crystallized masses. These contain 63 per cent of water, which slowly escapes when the salt is exposed to the air, leaving the anhydrous (water-free) carbonate as a white, opaque powder. Carbonate of soda has a nauseous alkaline taste, not nearly so decided, however, as that of the carbonate of potash. It is often present in the ashes of plants. Bicarbonate of Soda, NaHO COD.-The supercarbonate of soda of the apothecary is this salt in a nearly pure state. The soda-saloeratus of commerce is a mixture of this with some simple carbonate. It is prepared in the same way as the bicarbonate of potash. The bicarbonates. both of potash and soda, give off half their carbonic acid at a moderate heat, and lose all of this ingredient by con-, tact with excess of any acid. Their use in baking depends upon these facts. They neutralize any acid (lactic or acetic) that is formed during.the "rising" of the dough, and assist to make the bread "' light" by inflating it with carbonic acid gas. Carbonate of Lime, CaO CO2, 112.-This compound is 131 HOW CROPS GROW. the white powder formed by the contact of carbonic acid with lime-water. When hydrate of lime is exposed to the air, the water it contains is gradually displaced by carbonic acid, and carbonate of lime is the result. Airslaked lime always contains much carbonate. This salt is distinguished from hydrate of lime by its being destitute of any alkaline taste. In nature carbonate of lime exists to an immense extent as coral, chalk, marble, and limestone. These rocks, when strongly heated, especially in a current of air, part with their carbonic acid, and quick-lime remains behind. Carbonate of lime occurs largely in the ashes of most plants, particularly of trees. In the manufacture of potash, it remains undissolved, and constitutes a chief part of the residual leached ashes. The carbonate of lime found in the ashes of plants is supposed to come mainly from the decomposition by heat of organic salts of lime, (oxalate, tartrate, malate, etc.,) which exist in the juices of the vegetable, or are abundantly deposited in its tissues in the solid form. Carbonate of lime itself is, however, not an unusual component Qf vegetation, being found in the form of minute, rhombic crystals, in the cells of a multitude of plants. THE SULPHATES which we shall notice at length are those of Potash, Soda, and Lime. Sulphate of Magnesia is well known as epsom salts, and Sulphate of Iron is copperas or green-vitriol. (Sulphate of Lithia is very similar to sulphate of potash.) Sulphate of Potash, KO20 SOs, 174.-This salt may be procured by dissolving potash or carbonate of potash in diluted sulphuric acid. On evaporating its solution, it is obtained in the form of hard, brilliant crystals, or as a white powder. It has a bitter taste. Ordinary potash, or pearl-ash, contains several per cent of this salt. Sulphate of Soda, Na.O So,, 142.-Glaube)s salt is 132 THE ASH OF PLANTS. the common name of this familiar substance. It has a bitter taste, and is much employed as a purgative for cattle and horses. It exists, either crystallized and transparent, containing 10 molecules, or nearly 56 per cent, of water, or anhydrous. The crystals rapidly lose their water when exposed to the air, and yield the anhydrous salt as a white powder. Sulphate of Lime, CaO SO3, 136.-The burned Plaster of Paris of commnerce is this salt in a more or less pure state. It is readily formed by pouring diluted sulphuric acid on lime or marble. It is found in the ash of most plants, especially in that of clover, the bean, and other legumes. In nature, sulphate of lime is usually combined with two molecules of water, and thus constitutes Gypsum, CaO SO, 2H10, which is a rock of frequent and extensive occurrence. In the cells of many plants, as for instance the bean, gypsum may be discovered by the microscope in the shape of minute crystals. It requires 400 times its weight of water to dissolve it, and being almost universally distributed in the soil, is rarely absent from the water of wells and springs. THE PHOSPHATES which require special description are those of Potash, Soda, and Lime. There exist, or may be prepared artificially, numerous phosphates of each of these bases. The chemist is acquainted with no less than thirteen different phosphates of soda. But three classes of phosphates have any immediate interest to the agriculturist. As has been stated (p. 117), hydrated phosphoric acid prepared by boiling anhy. drous phosphoric acid with water, is represented by the symbol 3H20, P,0O. The phosphates may be regarded as hydrated phosphoric acid in which one, two, or all the molecules of water are substituted by the same number of molecules of one or of several bases. We may illus 133 HOW CROPS GROW. trate this statement with the three phosphates of lime, giving in one view their mode of derivation, their sym. bols, and the names which we shall employ in this treatise. a.-3 HO20, P205 and CaO give HO20 and 2 H20O, CaO, P205O, the monocalcic * phosphate or acid-Aosphate of limne. b.-3 HO20, P205 and 2 CaO give 2 H20 and 110, 2 Ca 0 P205, the dicalcic * phosphate or neutral phosphate of lime. e.-3 H,0, P205 and 3 CaO give 3 HI20O and 3 CaO P, 0O, the tricalcic * phosphate or basic-phosphate of lime. Phosphates of Potash.-Of these salts, the neutral and subphosphates exist largely (to the extent of 40 to 50 per cent) in the ash of the kernels of wheat, rye, maize, and other bread grains. None of these phosphates occur in commerce; they closely resemble the corresponding sodasalts in their external characters. Phosphates of Soda.-Of these the disodic, or neutral phosphate, 2 NaO20, H1O, P205 + 12 Aqt, alone needs notice. It is found in the drug-stores in the form of glassy crystals, which contain 12 molecules (56 per cent) of water. The crystals become opaque if exposed to the air, from the loss of water. This salt has a cooling, saline taste, and is very soluble in water. Phosphates of Lime.-Both the neutral and subphosphate of lime probably occur in plants. The neutral or dicalcic salt, (2 CaO H,20, P,205 + 2 Aq), is a white crystalline powder, nearly insoluble in water, but easily soluble in acids. In nature it is found as a urinary concretion in * These names indicate the proportions of acid and base in the compounds, and may be translated into common English, thus: One-lime phosphate, twolime phosphate, and three-lime phosphate respectively. t The water which is found in crystallized salts and which usually may be expelled at a gentle heat, is termed water of crystallization, and is often designated by Aq., (from the Latin Aqua), to distinguish it from basic water, which is more Intimately combined. 134 THE ASH OF PLANTS. the sturgeon of the Caspian Sea. It is also an ingredient of guanos, and probably of animal excrements in general. The tricalici phospActte, or, as it is sometimes termed, the bone-phosphate, 3 CaO, PO05, is a chief ingredient of the bones of animals, and constitutes 90 to 95 per cent of the ash or earth of bones. It may be formed by adding a solution of lime to one of phosphate of soda, and appears as a white precipitate. It is insoluble in pure water, but dissolves in acids and in solutions of many salts. In the mineral kingdom tricalcic phosphate is the chief ingredient of apatite and phosphorite. These minerals are employed in the preparation of the so-called superphosphate of lime, which is consumned to an enormous extent as a turnip-fertilizer. The saperphosphate of commerce, when genuine, is essentially a mixture of sulphate of lime with the three phosphates above noticed, of which the monocalcic phosphate should predominate. The Phosphates of Magnesia, Iron, and Manganese, are bodies insoluble in water, and require no particular notice. THE CHLORIDES are all characterized by their ready solubility in water. The chlorides of Lithium, Calcium, and Magnesium, are deliquescent, i. e., they liquefy by absorbing moisture from the air. The chlorides of Potassium and Sodium alone need to be described. Chloride of Potassium, K C1, 74.5.-This body may be produced either by exposing metallic potassium to chlorine gas, in which case the two elements unite together directly; or by dissolving caustic potash in chlorhydric acid. In the latter case water is also formed, as is expressed by the equation K HO + HC1 = K C1 + H20. Chloride of potassium closely resembles common salt (chloride of sodium) in appearance, solubilLty in water, taste, etc. It is but rarely an article of commerce, but is present in the ash and in the juices of plants, especially of sea-weeds, and is likewise found in all fertile soils. 135 HOW CROPS GROW. Chloride of Sodium, Na C1, 58.5-This substance is common or culinary salt. It was formerly termed mutriate of soda. It is scarcely necessary to speak of its occurrence in immense quantities in the water of the ocean, in saline springs, and in the solid form as rock-salt, in the earth. Its properties are so familiar as to require no description. It is rarely absent from the ash of plants. Besides the salts and compounds just described, there occur in the living plant other substances, most of which have been indeed already alluded to, but may be noticed again connectedly in this place. These compounds, being destructible by heat, do not appear in the analysis of the ash of a plant NITRATES: Nitric aci-the compound by which nitrogen is chiefly furnished to plants for the elaboration of the albuminoid principles-is not unfrequently present as a nitrate in the tissues of the plant. It usually occurs there as Nitrate of Potash, (niter, saltpeter.' The properties of this salt scarcely needcl description. It is a white, crystalline body, readily soluble in water, and has a cooling, saline taste. When heated with carbonaceous matters, it yields oxygen to them, and a deflagration, or rapid and explosive combustion, results. Touchpaper is paper soaked in solution of niter, and dried. The leaves of the sugar-beet, sun-flower, tobacco, and some other plants, have been found to contain this salt. When such vegetables are'burned, the nitric acid is decomposed, often with slight deflagration, or glowing like touch-paper, and the alkali remains in the ash as carbonate. The characters of nitric acid and the nitrates will be noticed at length in another volume, " How Crops Feed." OXALATES, CITRATES, MALATES, TARTRATES, and salts of other less common organic acids, are generally to be found in the tissues of living plants. On burning, the bases with which they were in combination-potash and lime in most cases-remain as carbonates. 136 I I THE ASH OF PLANTS. SALTS OF AMMONIA exist in minute amount in some plants. What particular salts thus occur is uncertain, and special notice of them is unnecessary in this chapter. Since it is possible for each of the acids above described to unite with each of the bases in one or several proportions, and since we have as many oxides and chlorides as there are metals, and even more, the question at once arises-which of the 60 or more compounds that may thus be formed outside the plant, do actually exist within it? In answer, we must remark that all of them may exist in the plant. Of these, however, but few have been proved to exist as such in the vegetable organism. As to the state in which iron and manganese occur, we know little or nothing, and we cannot assert positively that in a given plant potash exists as phosphate, or sulphate, or carbonate. We judge, indeed, from the predominance of potash and phosphoric acid in the ash of wheat, that phosphate of potash is a large constituent of the grain, but of this we are not sure, though in the absence of evidence to the contrary we are warranted in assuming these two ingredients to be united. On the other hand, carbonate of lime and sulphate of lime have been discovered by the microscope in the cells of various plants, in crystals whose characters are unmistakeable. For most purposes it is unnecessary to know more than that certain elements are present, without paying attention to their mode of combination. And yet there is choice in the manner of representing the composition of a plant as regards its ash-ingredients. We do not, indeed, speak of the calcium or the silicon in the plant, but of lime and silica, because the idea of these rarely seen elements is much more vague, except to the chemist, than that of their oxides, with which every one is familiar. Again, we do not speak of the sulphates or chlorides, 137 HOW CROPS GROW. when we desire to make statements which may be com. pared together, because, as has just been remarked, we cannot always, nor often, say what sulphates or what chlorides are present. In the paragraphs that follow, which are devoted to a more particular statement of the mode of occurrence, relative abundance, special function, and indispensability of the fixed ingredients of plants, will be indicated the customary and best method of defining them. ~ 2. QUANTITY, DISTRIBUTION, AND VARIATIONS OF THE ASH' INGREDIENTS. The ash of plants consists of the various fixed acids, oxides, and salts, noticed in ~ 1. The ash-ingredients are always present in each cell of every plant. The ash-ingredients exist partly in the cell-wall, incrusting or imbedded in the cellulose, and partly in the plasma or contents of the cell, (see p. 224.) One portion of the ash-ingredients is soluble in water, and occurs in the juice or sap. This is true, in general, of the salts of the alkalies, and of the sulphates and chlorides of magnesium and calcium. Another portion is insoluble, and exists in the tissues of the plant in the solid form. Silica, the phosphates of lime, and the magnesia compounds, are mostly insoluble. The ash-ingredients may be separated from the volatile matter by burning or by any process of oxidation. In burning, portions of sulphur, chlorine, alkalies, and phosphorus, may be lost under certain circumstances, by volatilization. The ash remains as a skeleton of the plant, and often actually retains and exhibits the microscopic form of the tissues. The Proportion of Ash is not invariable, even in the 1.38 I THE ASH OF PLANTS. same kind of plant, and in the same part of the plant. Different kinds of plants often manifest very marked differences in the quantity of ash they contain. The following table exhibits the amount of ash in 100 parts, (of dry tnatter,) of a number of plants and trees, and in their several parts. In all cases is given the average proportion, as deduced from a large number of the most trustworthy examinations. In some instances are cited the extreme proportions hitherto put on record. PROPORTIONS OF ASH IN VARIOUS VEGETABLE MATTERS. ENTIRE PLANTS, ROOTS EXCEPTED. averse average Red clover.................... 6.7 Turnips, 10.7-19.7...........15.5 White".................. 7.2 Carrot, 15.0-21.3.............17.1 Timothy..................... 7.1 Hops......................... 9.9 Potatoes..................... 5.1 Hemp....................... 4.6 Sugar beet, 16.3-18.6.........17.5 Flax.......................... 4.3 Field beet, 14.0-21.8.......18.2 Heath....................... 4.5 ROOTS AND TUBERS. Potato, 2.6-8.0.............. 4.1 Turmip; 6.0-20.9..............12.0 Sugar beet, 2.9-6.0............4.4 Carrot, 5.1-10.9.............. 8.2 Field beet, 2.8-11.3...........7.7 Artichoke.................... 5.2 STRAW AND STEMS. Wheat, 3.8-6.9.............. 5.4 Peas, 6.9.4.................7.9 Rye, 4.9-56..................5.3 Beans, 5.1-7.2................6.1 Oats, 5.0-5.4..............5.3 Flax...................... 3.7 Barley.........................6.8 Maize.........................5.5 GRAINS AND SEED. Wheat, 1.5-3.1...............2.0 Buckwvbeat, 1.1-2.1............1.4 Rye, 1.6-2.7...............2.0 Peas, 2.4-2.9..................2.7 Oats, 2.5-4.0..................3.3 Beans, 2.7-4.3................3.7 Barley, 1.8-2.8................2.3 Flax...........................3.6 Maize, 1.3-2.1................1.5 Sorghum......................1.9 WOOD. Beech.........................1.0 Red Pine......................0.3 Birch..........................0.3 White Pie...................0.3 Grape.........................2.7 Fir............................0.3 Apple.........................1.3 Larch.........................0.3 BARK. Birch................1.3 Fir........................... 2.0 Red pine.....................2.8 Walnut........................6.4 White pine....................3.3 Cauto tree.................... 4 139 HOW CROPS GROW. From the above table we gather: 1. That different plants yield different quantities of ash. It is abundant in succulent foliage, like that of the beet, (18 per cent,) and small in seeds, wood, and bark. 2. That different parts of the same plant yield unlike proportions of ash. Thus the wheat kernel contains 2 per cent, while the straw yields 5.4 per cent. The ash in su gar-beet tops is 17.5; in the roots, 4.4 per cent. In the ripe oat, Arendt found (lDas Wachsthum der ZHaferpflanze, p. 84,) In the three lower joints of the stem.... 4.6 per cent of ash In the two middle joints of the stem.... 5.3 " " In the one upper joint of the stem...... 6.4 " In the three lower leaves...............10.1 " " In the two upper leaves................10.5 " In the ear............................. 2.6 " 3.' We further find, that in general, the upper and outer parts of the plant contain the most ash-ingredients. In the oat, as we see from the above figures of Arendt, the ash increases from the lower portions to the upper, until we reach the ear. If, however, the ear be dissected, we shall find that its outer parts are richest in ash. Norton found In the husked kernels of brown oats... 2.1 per cent of ash In the husk of brown oats.............. 8.2 " " In the chaff of brown oats..............19.1 " " Norton also found that the top of the oat-leaf gave 16.22 per cent of ash, while the bottom yielded but 13.66 per cent. (Am. Jour. Science, Vol. 3, 1847.) From the table it is seen that wood, (0.3 to 2.7 per cent,) and seeds, (1.5 to 3.7 per cent,) (lower or inner parts of the plant,) are poorest in ash. The stems of herbaceous plants, (3.7 to 7.9 per cent,) are next richer, while the leaves of herbaceous plants, which have such an extent of surface, are the richest of all, (6 to 8 per cent.) 4. Investigation has demonstrated further that the same plant in different stages of growth varies in the propor 140 i THE ASH OF PLANTS. tions of ash in dry matter, yielded both by the entire plant and by the several organs or parts. The following results, obtained by Norton, on the oat, illustrate this variation. Norton examined the various parts of the oat-plant at intervals of one week throughout its entire period of growth. He found: Knots. Chaff. Grain urthusked, o.....t * Jyo13..... 4.9 Jl 98.... 4.3 Jl16 16... 6.0 3.3 10.0 9.1 3.6 9.6 12.2 4.2 10.4 13.7 4.3 10.4 18.6 4.0 11.7 21.0 3.6 11.2 22.4 3.5 10.7 27.4 3.6 and chaff, we observe a coil Leaves. June 4...... 10.8 June 11......10.7 June 18....... 9.0 June 25...... 10.9 July 2........ 11.3 July 9........ 12.2 July 16........ 12.6 July 23........ 16.4 July 30........ 16.4 Auk. 6...... 16.0 Aug. 13........ 20.4 Aug. 20........ 21.1 A-ag. 27........22.1 Sept. 3........ 20.9 stant increase of ash, while in the stem there is a constant decrease, except at the time of ripening, when these relations are reversed. The knots of the stem preserved a pretty uniform ash-content. The unhusked grain at first suffered a diminution, then an increase, and lastly a decrease again. Arendt found in the oat-plant fluctuations, not in all respects accordant with those observed by Norton. Arendt obtained the following proportions of ash: 3 lower 2 middle Upper Lowuer Upper Ears. Entire joints of joints of joint of leaves. leaves. plant. stern. stein. stern. June 18....4.4.... 9.7 7.7.. 8.0 June 30....2.5 2.9 3.5 9.4 7.0 3.8 5.2 July 10....3.5 4.7 5.2 10.2 6.9 3.6 5.4 July 21....4.4 5.0 5.5 10.1 9.7 2.8 5.2 July 31... 6.4 5.3 6.4 10.1 10.5 2.6 5.1 Here we see that the ashincreased in the stem and in each of its several parts after the first examination. The 141 Stem. 10.4 9.8 9.3 9.1 7.8 7.8 7.9 7.9 7.4 7.6 6.6 6.6 7.7 8.3 Here, in case of the leaves t HOW CROPS GROW. lower leaves exhibited an increase of fixed matters after the first period, while in the upper leaves the ash dimin ished toward the third period, and thereafter increased. In the ears, and in the entire plant, the ash decreased quite regularly as the plant grew older. Pierre found that tLe proportion of ash of the colza, (Brassica oleracea,) diminished in all parts of the plant, (which was examined at five periods,) except in the leaves, in which it increased. (,Tahresbericht fiber Agrictlturchemie, III, p. 122.) The sugar beet, (Bretschneider,) and potato, (Wolff,) exhibit a decrease of the per cent of ash, both in tops and roots. In the turnip, examined at four periods, Anderson, (Trans. Gigh. and Ag. Soc., 1859-61, pv. 371,) found the following per cent of ash in dry matter: Jurly 7. Aug. 11. Sept. 1. Oct. 5. Leaves................. 7.8 20.6 18.8 16.2 Bulbs...................17.7 8.7 10.2 20.9 In this case, the ash of the leaves increased during about half the period of growth from 7.8 to 20.6, and thence diminished to 16.2. The ash of the bulbs fluctuated in the reverse manner, falling fiom 17.7 to 8.7, then rising again to 20.9. I)? general, the proportion of ash of the entire plant diminishes regularly as the plant grows old. 5, The influence of the soil in causing the proportion of ash of the same kind of plant to vary, is shown in the following results, obtained by Wunder, ( Versuchs-Stationen, IFV, p. 266,) on turnip bulbs, raised during two successive years, in different soils. It sandy soil. In loamy soil. 18t year. 2d year. 1st year. 2d year. Per cent of ash.... 13.9 11.3 9.1 10.9 ,6. As might be anticipated, different varieties of the same plant, grown on the same soil, take up different / quantities of non-volatile matters. In five varieties of potatoes, cultivated in the same soil 142 f iI THE ASH OF PLANTS. and under the same conditions, Herapath, (Qu. Joour. Chem. Soc., II, p. 20,) found the percentages of ash in dry matter of the tuber as follows: Variety of potato. Whlite P'ince's Axbridgqe MIagpie. Forty Apple. Beauty. Kidntey. fold. Ash per cent.......... 4.8 3.6 4.3 3.4 3.9 7. It has been observed further that diferent individuals of the same variety ofplant, growing side by side, on the same soil, (in the same field at least,) contain different proportions of ash-ingredients, according as they are, on the one hand, healthy, vigorous plants, or, on the other, weak and stunted. Pierre, (Tahresbericht uiber Agriculturchemie, III, p. 125,) found in entire colza plants of various degrees of vigor the following percentages of ash in dry matter: In extremely feeble plants, 1856......... 8.0 per cent ofash In very feeble plants, 1857.............. 9.0 "" In feeble plants, 1857...................11.4 " In strong plants, 1857..................11.0 " " In extremely strong plants, 1857........14.3 " " Pierre attributes the larger per cent of ash in the strong plants to the relatively greater quantity of leaves developed on them. Similar results were obtained by Arendt in case of oats. Wunder, ( Versuchs-St., IV, p. 115,) found that the leaves of small turnip plants yielded somewhat more ash, per cent, than large plants. The former gave 19.7, the latter 16.8 per cent. 8, The reader is prepared from several of the foregoing statements to understand partially the cause of the variations in the proportion of ash in different specimens of the same kind of plant. The fact that different parts of the plant are unlike in their composition, the upper and outer portions being, in general, the richer in ash-ingredients, may explain in some degree why different observers have obtained different analtical results. It is well known that a variety of circumstances in 143 HOW CROPS GROW. fluences tne relative development of the organs of a plant. In a dry season, plants remain stunted, are rougher on the surface, have more and harsher hairs and prickles, if these belong to them at all, and develope firuit earlier than otherwise. In moist weather, and under the influence of rich manures, plants are more succulent, and the stems and foliage, or vegetative parts, grow at the expense of the re productive organs. Again, different varieties of the same plant, which are often quite unlike in their style of devel opment, are of necessity classed together in our table, and under the same head are also brought together plants gathered at different stages of growth. In order that the wheat plant, for example, should always have the same percentage of ash, it would be necessary that it should always attain the same relative development in each individual part. It must, then, always grow under the same conditions of temperature, light, moisture, and soiL This is, however, as good as impossible, and if we admit the wheat plant to vary in form within certain lim its without losing its proper characteristics, we must ad mit corresponding variations in composition. The difference between the Tuscan wheat, which is cul tivated exclusively for its straw, of which the Leghorn hats are made, and the "pedigree wheat" of Mr. Hallett, (Journal Roy. Ag. Soc. of Eng., Vol. 22, p. 374,) is in some respects as great as between two entirely different plants. The hat wheat has a short, loose, bearded ear, containing not more than a dozen small kernels, while the pedigree wheat has shown beardless ears of 81 inches in length, closely packed with large kernels to the number of 120! Now, the hat wheat, if cultivated and propagated in the same careful manner as has been done with the pedigree wheat, would, no doubt, in time become as prolific of grain 's the latter, while the pedigree wheat might perhaps with greater ease be made more valuable for its straw than its grain. 144 i i. I iI 11 i THE ASH OF PLANTS. We easily see then, that, as circumstances are perpetually making new varieties, so analysis continnly finds diversities of composition. 9. Of all ehe part's 0/planes Che seers t1e leasC liaie Co vary in composieion. Two varieties or two individus may differ enormously in their relative proportions of foliage, stem, chaff, and seed; but the seeds themselves nearly agree. Thus, in the analyses of 67 specimeus of the wheat kernel, collated by the author, tbe extreme percentages of ash were 1.35 and 3.13. In 60 specimens out of the 67, the range of variation fell between 1.4 and 2.3 per cent. In 42 the range was froui 1.7 to 2.1 per cent, while the average of the whole was 2.1 per cent. In the sCem8 or straw of tl)e grains, the variation is much more considerable. Wheat-straw ranges from 3.8 to 6.9; pea-straw, from 6.5 to 9.4 per cent. In fles/ roots, the variations are great; thus turnips range from 6 to 21 per cent. The extremest variations in ash-content are, however, found, in general, in the succulent foliage. Turnip tops range from 10.7 to 19.7; potato tops vary from 11 to near 20, and tobacco from 19 to 27 per cent. Wolff, (J)ie naturgeseCzlichen aun~llagen s Aelcer6aues, 3. Aufi., p.117,) has deduced from a large number of analyses the following averages for three important Grain. Straw. Cereal crops 2 5.25 per cent Leguminous crops 3 5 " " Oil-plants 4 4.5 " " ]Iore general averages are as follows, (Wolff loc. cit.): Annual and biennialplants. Perennial plants. Seeds - - - 3 per cent Seeds - - - 3 per cent Stems - -5 " " Wood- - - - 1 " " Roots - - - 4 " " Bark - - - 7 " " Leaves- - 15 Leaves - - - 10 " 7 145 HOW CROPS GROW. We may conclude this section by stating three propositions which are proved in part by the facts that have been already presented, and which are a summing up of the most important points in our knowledge of this subject. I. Ash-ingredients are indispensable to the life and growth of all plants. In mold, yeast, and other plants of the simplest kind, as well as in those of the higher orders, analysis never fails to recognize a proportion of fixed matters. We must hence conclude that these are necessary to the primary acts of vegetation, that atmospheric food cannot be assimilated, that vegetable matter cannot be organized, except with the cooperation of those substances, which are found in the ashes of the plant. This proposition is demonstrated further in the most conclusive manner by numerous synthetic experiments. It is, of course, impossible to attempt producing a plant at all without some ashingredients, for the latter are present in all seeds, and during germination are transferred to the seedling. By causing seeds to sprout in a totally insoluble medium, we can observe what happens when the limited supply of fixed matters in the seeds themselves is exhausted. Wiegmann & Polstorf, (PreisscArift inber die unorganischen Bestandtheile der Pjlanzen,) planted 30 seeds of cress in fine platinum wire contained in a platinum vessel. The contents of the vessel were moistened with distilled water, and the whole was placed under a glass shade, which served to shield from dust. Through an aperture in the shade, connection was made with a gasometer, by which the atmos phere in the interior could be renewed with an artificial mix ture, consisting in 100, of 21 parts oxygen,78 parts nitrogen, and 1 part carbonic acid. In two days 28 of the seeds germinated; afterwards they developed leaves, and grew slowly with a healthy appearance during 26 days, reaching a height of two to three inches. From this time on, thev refused to grow, began to turn yellow, and died down. The plants were collected, and burned; the ash firom them 146 /) THE ASH OF PLANTS. weighed precisely as much as that obtained by burning 28 seeds like those originally sown. This experiment demon strates most conclusively that a plant cannot grow in the absence of those substances found in its ash. The devel opment of the cresses ceased so soon as the fixed matters of the seed had served their utmost in assisting the organ ization of new cells. We know fi'om other experiments that, had the ashes of cress been applied to the plants in the above experiment, just as they exhibited signs of un healthiness, they would have recovered, and developed to a much greater extent. If. The proportion of ash-ingredients in theplant is va riable within a narrow range; but cannot fall below or exceed certain limits. The evidence of this proposition is to be gathered both from the table of ashl-percentages, and from experiments like that of Wiegmann & Polstorf above described. III. We have reason to believe that each part or organ, (each cell,) of the plant contains a certain, nearly invariable amount of fixed matters, which is indispensable to the vegetative functions. Each part or organ may contain, besides, a variable and unessential or accidental quantity of the same. What portion of the ash of any plant is essen tial and what accidental is a question not yet brought to a satisfactory decision. By assuming the truth of this proposition, we account for those variations in the amount of ash which cannot be attributed to the causes already noticed. The evidences of this statement must be reserved for the subsequent section. ~ 3. SPECIAL COMPOSITION OF THE ASH OF AGRICULTURAL PLANTS. The results of the extended inquiries which leave been recently made into the subject of this section may be con 147 HlOW CROPS GROW. veniently presented and discussed under a series of propo. sitions, viz.: 1. Among the substances which have been described, (~ 1,) as the ingredients of the ash, the following are invariably present in all agricultural plants, and in nearly allparts of them, viz.: Potash Cllorine Soda Sulphuric acid Bases Lime Acids Phosphoric acid Magnesia Silicic acid Oxide of iron Carbonic acid 2. Different normal specimens of the same kind of plant have a nearly constant composition. The use of the word nearly in the above statement implies what has been already intimated, viz., that some variation is noticed in the relative proportions, as well as in the total quantity, of ash-ingredients occurring in plants. This point will shortly be discussed in full. By taking the average of many trustworthy ash-analyses, we arrive at a result which does not differ very widely from the majority of the individual analyses. This is especially true of the seeds of plants, which attain nearly the same development under all ordinary circumstances. It is less true of foliage and roots, whose dimensions and character vary to a great extent. In the following tables (p. 150-156) is stated the composition of the ashes of a number of agricultural products, which have been repeatedly subjected to analysis. In most cases, instead of quoting all the individual analyses, a series of averages is given. Of these, the first is the mean of all the analyses on record or obtainable by the writer,* while the subsequent ones represent either the results obtained in the examination of a number of samples by one analyst, or are the mean of several silgle anal * The numerous ash-analyses, published by Dr. E. Emmons and Dr. J. IL Salisbury, in the Natural History of New York, and in the Trans. of the N.Y. State Ag. Society have been disregarded on account of their manifest worthless ness and absurdity. 148 II THE ASH OF PLANTS. yses. In this way, it is believed, the real variations of composition are pretty truly exhibited, independently of the errors of analysis. The lowest and highest percentages are likewise given. These are doubtless in many cases exaggerated by errors of analysis, or by impurity of the material analyzed. Chlorine and sulphuric acid are for the most part too low, because they are liable to be dissipated in combustion, while silica is often too high, from the fact of sand and soil adhering to the plant. In two cases, single and perhaps incorrect analyses by Bichon, which give exceptionally large quantities of soda, are cited separately. A number of analyses that came to notice after making out the averages, are given as additional. The following table includes both the kernel and straw of Wheat, Rye, Barley, Oats, Maize, Rice, Buckwheat, Beans, and Peas; the tubers of Potatoes; the roots and tops of Sugar Beets, Field Beets, Carrots, Turnips, and various parts of the Cotton Plant. For the average composition of other plants and vegletable products, the reader is referred to a table in the appendix, p. 376, compiled by Prof. Wolff, of the Royal Agricultural Academy of Wurtemberg. That table includes also the averages obtained by Prof. Wolff for most of the substances, cotton excepted, whose composition is represented in the pages immediately following. Any discrepancies between Prof. Wolff's and the author's figures are for the most part due to the use of fewer analyses by the former. In both tables, the carbonic acid, which occurs in most ashes, is excluded, from the fact that its quantity varies according' to the temperature at which the ash is prepared 149 COMPOSITION OF THE ASH OF SOME AGRICULTURAL PLANTS AND PRODUCTS, Arrangqed to exhibit the Extent of Variations. ot.f O| Lh|dlOxi Sdel- Sul. Of a8h.' - neSo a. Iron. -i phu~a" rine. ~~~~~~~~Io.lAci. Acid.fie WHEAT KERNEL. ... 31.3 3.2 12.3 3.2... 46.1... 1.9... Average of 79 Analyses. 2.3 30.0 9.0 10.9 2.2... 48.1 0.1 0.1 60.5 5 by J. Herapath. 1.9 31.4 3.2 12.3 3.5 0.8 45.0 0.5 3.0 0.4 " 26 " Way & Ogston. 2.4 28.0 2.7 11.5 2.4 0.6 50.0 2.2 2.0 0.7 " 9 " Zoeller. 2.0 33.7 2.6 12.7 3.3... 44.5... 0.8... " 30 "' Bibra. 27.3 4.3 12.2 3.0 0.7 50.0 0.1 1.6 0.7 " 9 o" thers.* 1.6 2.0 0.0 0 6.3 0.9 0.0 34.4 0.0 0.0 0.0 Lowest percentin 79 Analyses. 3.1 38.4 15.9 16.3 8.2 3.3 60.4 2.4 7.6 6.1 Highest " * 79 " 2.6 6.4 27.8 12.9 3.9 0.5 46.1 0.3 0.4...Old Analysis byBichon, not inclnded above. 2.5 30.6 2.5 10.0 4.1 1.1 47.4 1.2 5.6 0.7 Recent Analysis by Anderson, not included above. RYE KERNEL. 0 0 td 2.0 28.8 4.3 11.6 3.9... 4.6... 2.6 2.0 29.1 0.3 11.5 3.0 0.9 48.6 2.5 1.5 2.1 33.5 2.1 12.2 2.1... 45.6.. 1.5 1.9 25.4 8.2 11.3 5.9 1.2 42.2 607 4.5 1.6 9.4 0.0 10.1 1.3 0.5 25.1 0.5 0.60 2.7 37.5 20.8 14.4 15.3 2.2 51.8 3.0 14.6 BARLEY Kt 21.2 3.5 8.2 2.3... 32.8 2.0 28.4 2.1 26.7 2.1 8.4 2.4 0.8 32.1 1.0 25.3 2.9 18.5 3.9 7.0 2.7 0.7 32.4 2.8 31.1 2.2 18.4 2.8 11.7 2.3... 35.9 3.3 24.6 2.5 22.3 3.7 8.2 3.8 1.2 28.3 1.9 31.1 2.5 17.0 7.0 6.8 2.6 1.1 36.4 0.8 30.6 1.8 13.8 0.6 4.3 0.7 0.1 26.0 0.2 22.1 2.8 31.6 8:9 14.7 4.2 2.4 39.8 4.0 36.7 2.4 3.9 16.8 10.1 3.4 1.9 40.6 0.3 22.0 2.5 17.0 5.9 7.2 2.7 0.5 30.3 1.4 33.1 2.5 17.0 6.3 6.8 3.1 0.5 lost 1.5 33.7 Viz: Schmidt, Thon Will & Fresenius, Boussin, ault, V Schulze, Will & Freseniu's, Bichoul, Geradew'ohl, Sch~ulz-Flez Average of 21 Analyses. " 8 " by Zoeller. " 5 " "Bibra. " 8 " " others.t Lowest per cent in 21 Analyses. Highest " 21 " L WITH HUSK. Average of 43 Analyses. 13 " by Way & Ogston. " 14 " " Zoeller. 6 " "Bibra. " 5 " "John. " 5 " "others.: Lowest per cent in 43 Analyseg. Highest " 43' Old Analysis by Bichon. Recent additional Analysis by Veltman. -. " " " Moesman. Petzholdt, Baer, F~r. Schulze. Viz: t Herapath, Way &; Ogston, Fr. Viz: Joh'n, Sch'midt, Koechlin, Thomson._ I i 0CA C> 0.. 2.5 ~RNE 1.1 ... 0.9 0.2 2.5 ERNE 0.3 ber, C,' Ct. P. Oxide o,. C , as h. Soda. a. |lime.| Iron, p cphurc Silica. li | ~A.d. Acid. OAT KERNEL WITH HUSK. 0.5 21.3 1.5 46.4 0.4 Average of 21 Analyses. 0.5 22.6 1.6 44.9 0.6 " 11 " byWa 0.8 19.8 1.6 48.0 0.8 " 10 " "oth 0.1 9.7 0.1 38.0 0.0 Lowest percentage in 21 Analyi 2.1 32.3 4.0 56.5 1.6 Highest " 21 MAIZE KERNEL. 0.8 46.8 1.5 1.6... Average of 8 Analyses. 0.5 53.7... 1.6... Way & Ogston. 0.6 39.6 5.5 2.1... Fromberg. ... 50.1... 0.8... Letellier. 0.9 44.6... 3.9 0.2 W. Hi. Brewer. ndet 45.0 undet undet undet Stepf.t 1.9 49.4 1.0 2.8 trace Bibra. 2.0 47.5 1.2 1.9 " " 0.8 44.5 4.1 1.8' 0.5 Campbell. 172. 0 3 1.4 35.0?? 3.6 Lowest per cent in3Analyses 9.6 40.4?? 4.5 Highest " " 0.5 35.0 0.0 0.8 0.0 Lowest per cent in 11 Analysei 9.6 53.7 5.5 3.9 4.5 Highest " " RICE KERNEL WITHOUT HUSK. .. 53.7 2.7... Average of 5 Analyses. 0.5 53. 4... 3.4 0.3 Johnston. 2.0 62.3... 1.4... Zedeler. ? 46.3 1.3 3.4 0.5 Bibra. ? 54.0 0.6 3.0 trace " ? 52.6 trace 2.5 trace " . 46.3. 1.4... Lowest per cent in 5 Analyses ... 62.3... 3.4... Highest ". ... 27.8 3.9 15.0 1.5 28.4 1.7 13.0 ... 26.6 7.5 15.4 30.8 0.0 17.0 2.1 26.0 13.2 13.3 ... 28.8 3.5 14.9 1.3 24.3 1.5 16.0 1.3 26.7 3.9 15.2 ... 30.7... 14.7 1.7 23.7 0.0 11.3 1.9 29.6 0.0 16.0 1.3 23.7 0.0 11.3 2.1 30.8 13.2 17.0 0.5 21.7 5.5' 11.2 3.2 1.0 18.5 10.7 11.7 1.3 0.4 20.2 2.5 4.2 7.2 0.3 22.2 6.3 12.4 5.9 0.2 22.3 4.0 14.3 1.1 0.7 25.4 4.1 13.4 0.8 0.2 18.5 2.5 4.2 0.8 1.0 25.4 10.7 14.3 7.2 * Viz: Herapath, Boussingault, Porter, Fr. Schulze, Knop & Schnedermann, Bretschneider, I Analyses not accessible. 15.6 2.5 7.2 3.2 16.6 2.6 7.0 3.4 14.5 2.6 7.5 2.5 9.8 0.3 4.9 4.0 24.3 8.2 9.7 COMPOSITION OF THE ASH OF SOME AGRIQULTURAL PLANTS AND PRC | o |7Pr flCt.'lo 2e-|Pho8 Pofa. Ma- Lime. Oxid - - S~.lpopa. 1,',. Pkc uIrz]c Silioa. as.nesia. 4rn.Aid cid line. ff.{ash. RICE KERNEL WITH HUSK. 8.2 17.5 5.6 10.7 4.0. 40.6......... Averageof 2 Analyses ,1 17.7 5.2 10.3 1.0? 41.4 0.4 trace 04 Bibra. '.3 17.4 5.8 11.2 7.0? 39.9 1.4 0.5 1.4. BUCKWHEAT KERNEL. 2.1 8.7 20.1 10.4 6.7 1.1 50.1 2.2 0.7 Analysis by Bichon. 1.1 20.8 9.0 12.3 4.8 2.3 46.7 2.1... 2.0 " Bibra. 1.1 25.4 3.2 14.5 1.8 1.9 49.2 2.1... 1.9 PEA KERNEL. ... 40.9 3.1 7.6' 5.4 0.8 35.3 4.3 0.8 1.4 Average of 31 Analyses. ... 42.3 0.9 8.0 4.8 1.0 37.6 2.7 0.6 1.8 14 " forPr . 39.5 7.9 7.1 3.6 0.3 31.6 7.1 0.5 0.1 " 5 " by Jo 2.7 42.4 1.5 6.7 6.6 0.6 34.0 5.7 1.4 1.7 " 7 " W ... 36.3 6.6 8.2 7.0 0.9 34.4 3.9 0.9 1.2 " 5 otl 2.4 34.2 0.0 5.8 2.2 0.0 25.0 0.0 0.2 0.0 Lowest percentin31Analysei 2.9 45.7 12.9 12.2 13.2 3.8 44.4 9.4 2.6 6.5 Highest " "31 BEAN KERNEL. 38.5 6.0 7.3 6.3' 0.2 34.6 3.2 0.8 1.5 Averageof 18 Analyses. 3.7 35.4 1.9 5.7 4.5... 38.5 3.6 0.4 3.4 " 4 byRit 3.0 44.7 1.7;6.7 8.3 0.3 32.1 4.4 0.8 1.1 7 " Wa 4.3 34.0 12.6 8.9 5.4 0.3 34.9 1.7 0.9 0.8 " 7 " "oth 2.7 20.8 0.0 5.1 3.1 0.0 27.1 1.3 0.0 0.0 Lowest percentage of 18Anal, 4.3 53.6 22.8 12.0 13.4 1.0 41.2 6.4 2.5 6.0 Highest " 18' ... 43.1 0.2... 6.3... 32.7 3.3...... Recent Analysis byHenneber WHEAT STRAW AND CHAFF. 11.5 1.6 2.5 5.8 0.7 5.3 2.5 69.1 1.1 Averageof 15 Analyses. 11.6 0.7 2.4 5.9 0.5 6.0 3.2 69.6 " 9 byWa 5.4 11.3 3.0 2.6 5.6 0.9 4.2 1.4 68.4 2.8 6 " oth 3.8 1.3 0.0.0 2.7 0.1 2.2 0.7 60.6 0.0 Lowest percentage in 15 Anal 6.9 16.7 7.8 5.2 8.8 1.8 8.9 5.6 73.6 9.4 Highest " 15 * Viz: Will & Fresenius, Bichon, Thon, Boussingault, Baer. t Viz: Herapath, Bichon, Viz: Chaff included. ~ Viz: Petzholdt, Baer, Weber, Boussingault, Zoeller, Henneberg & St( cluded is uncertain. act|.,~^ |Soda.|Ma2?< |Lime~lOI~idelphclph8"clsilicalcrhto- II Pr Me L Oi P1hos- SuIa8r Ct.{ lo- Mal Li me. Oxid-e p hc phuric Silica. ffAc a~h. iron. AcP-4 id.?,n -1 RYE STRAW. I5.2 15.4 2.6 2.9 7.9 0.8 5.3 1.9 58.8 1.4 Averageof5Analyses.* 4.9 9.8 0.0 2. 3 5.5 0.2 3.8 0.8 46.5 0.0 Lowest percentage in 5 Analyses. 6.3 30.8 6.3 3.4 9.6 1.9 7.4 2.5 65.2 3.2 Highest " 5 ta 4.2......... 17.0 1.0 4.5... 50.1... Recent incomplete Anal. by Henneberg & Stohmann not included BARLEY STRAW. 21.6 4.1 2.4 7.7.. 4.5 3.7 54.1... Average of 17 Analyses. 5.5 12.0 4.6 3.0 7.3 1.9 6.0 2.8 59.7 2.6 " 4 " by Zoeller. 4.9 15.4 3.5 2.6 9.0 0.8 4.1 2.6 59.8 2.6 " 5 " "Way & Ogston. 30.6 4.3 1.9 7.1... 4.0 4.9 47.6... " 8 " "Wolff. 3.2 10.8 1.1 1.7 5.3 0.2 2.2 1.1 49.9 1.3 Lowest percentage in 9 Analyses, Wolff's excluded. 5.9 20.9 5.7 3.1 13.1 2.0 7.2 3.3 68.5 3.9 IHighest 9 OAT STRAW. 20.5 6.4 3.8 7.4 1.6 4.1 3.3 49.5 3.6 Average of 5 Analyses. {Averageof 5 Anlyss 5.2 21.4 4.3 8.8 7.0 1.5 5.2 8.4 50.2 3.9 3 byWay&O Ogston. ... 19.2 9.7 3.8 8.1 1.8 2.6 3.2 48.4 8.3 " 2 " "Levi, and Boussingault. 5.0 12.2 2.8 2.3 4.9 0.7 1.9 2.2 42.6 1.5 ILowest percentage in 5 Analyses. 5.4 26.1 14.7 5.5 8.8 2.7 7.3 4.4 54.3 7.0 Highest " 5 " ............9.6 0.9 3.3... 31.4 4.0 Recent Analysis by Henneberg & Stohmann, not included above. MAIZE STALKS. 5.5 86.3 1.25 5.7 10.8 2.4 1 8.3 [ 5.2 1 28.8 1... I[Way & Ogston. BUCKWHEAT STRAW. 6.15 46.6 2.2 3.6 18.4 }? 11.9 1 5.8 1 5.5 ] 7.7 I[Average of 6 Analyses by Wolff. PEA STRAW. 21.4 5.7 7.2 38.8 1.4 7.1 6.1 5.4 - 6.3 Average of 22Analyses. 4.8 23.2 5.3 7.6 35.0 1.4 9.0 6.2 5.7 7.3 18 " for Prussian Landes Oec. Collegium.t 7.9 20.7 5.3 8.6 49.5 1.8 4.1 5.3 5.38 8.3 " 6 " by Way & Ogston. 8.1 15.1 8.3 9.5 37.1 0.8 8.3 7.7 4.8 7.7' 3 " others.$ 3.4 0.4 0.0 3.3 17.3 0.0 1.7 0.8 0.6 0.0 Lowestpercentage in22Analyses. 1.3 36.5 24.1~ 13.9 67.4 3.5 18.2 16.0 21.4 16.2 Highest " 22 " .. 24.1~ 0.3 12.9 36.3 1.8 4.7 8.3 3.3 10.9 AnalysisbyBaer.~ * By Will & Fresenius, Schulz-Fleeth, Zoeller, Rautenberg. t By Rammelsberg, Nitzsch, Liebig, Marchand, Steinberg, Schulze Krocker, Weber, Heintz, Erdmann, Stadeler. $ Viz: Boussingault, Baer, HertAig. ~ The Analysis by Heintz for Pr. Landes Col. is like Baer's, except that the per cents of Potash and Soda in the one are the reverse of those in the other. The Analysis was doubtles made by Baer under direction of Heintz. and in one case has been erroneously copied. The next highest per cent of Soda is 15.1. tq 0 I4i,,, iC4 COMPOSITION OF THE ASH OF SOME AGRICULTURAL PLANTS AND P] t Ct. Pot- oda. Mag- Lime. Oxide pho- ph urSui-a. CAlo Soda.naia. Iro.Acid. Acid.Ph .A~~fh. Aoi~~~~d*. P~~~huardic Silica.~~~I BEAN STRAW. ... 32.7 8.7 7.3 25.3 1.7 7.9 2.2 5.5 7.3 Average of 9 Analyses. . 34.6 4.4 9.3 23.0 2.6 8.2 0.2 6.6 6.8 4 " by Rit 6.1 81.3 12.1 5.7 27.2 1.1 7.7 3.7 4.6 7.8 5 " 5 ".Wa 5.1 5.4 1.9 3.3 9.4 0.6 0.7 0.0 1.6 0.0 Lowest percentage in 9 Anal] 7.2 52.2 25.3 16.0 38.7 2.9 14.9 7.0 13.6 14.5 Ilighest " 9' .. 15.0 13.6 7.0 35.9 2.4 12.0 2.5 11.3 0.3 Old Analysis by Hertwig not POTATO TUBER. 60.9 1.7 4.6 2.4 0.9 18.3 7.0 1.9 2.7 Average of 39 Analyses. 4.1 66.1 0.4 3.9 1.4 0.7 18.7 3.3 0.8 5.5 7 " by Scl 3.7 62.5... 4.8 1.8 0.5 17.7 8.8 2.7 1.6 8 " Me ... 46.0 8.6 3.6 4.0 3.9 23.6 5.0 4.2 1.4 " 3 " W 4.1 67.6 0.3 4.7 3.6 0.0 17.6 5.8 0.0 0.3 " 5 " He ... 53.9 2.0 4.9 2.0 1.0 23.6 10.2 1.7 1.5 4 " Bre 59.5 2.2 5.1 4.0 1.3 18.5 3.0 2.8 3.9 " 3 " Wa 4.6 60.2 2.4 4.9 2.1 0.6 14.9 9.5 2.2 3.3 " 8 " oth 2.6 42.9 0.0 2.5 0.5 0.0 11.2 0.4 0.0 0.0 Lowest percentage in 39 Ana' 8.0 73.6 12.8 6.6 6.2 6.0 27.1 18.0 6.5 8.7 Hiighest " 39 4.5 64.8 1.4 4.3 2.0 1.9 16.8 4.7 1 4, 3.4 Average of 4 recent Analyses SUGAR BEET ROOT. 48.0 10.4 9.5 6.4 1.0 14.4 4.7 3.8 2.3 Average of 40 Analyses. 4.1 51.2 10.0 9.1 5.8 0.8 13.6 4.4 3.5 2.6 13 " by Ri 4.8 46.9 9.5 0.2 6.3 1.2 15.9 5.4 3.3 3.1 11 " Br 4.2 45.4 12.3 10.2 6.9 1.0 14.0 4.4 4.6 1.0 14 " "Br 5.2 50.9 5.8 6.7 9.8 1.1 16.3 4.0 3.4 1.9 Additional Analysis byH offir 2.9 51.8 6.7 7.5 7.0 2.2 12.9 2.8 3.2 5.9 " " Karm 2.9 22.0 5.1 4.5 3.9 0.3 10.2 2.1 1.6 0.5 Lowest percentage in40 Ana] 6.0 58.9 29.8 13.8 23.3 2.2 18.5 8.9 9.0 10.8 Highest " 40 * Viz: Moser, Fromberg, Boussingault, Cameron, John, Griepenkerl. ' |ot- Soda. Mag lm.Oi Siica. d Chlo IsA a. Lime. Iro. phurcilica. o. s.a ah. Acid. Acid. ELD BEET ROOT. 4.0 9.9 Average of 12 Analyses.' 3.2 21.3 " 3," by w3 2.7 5.0 " 3 " Rit 5.1 4.9 " 2 " "WC 5.1 7.6 " 4 " "oth 0.2 2.0 Lowest percentage in 12 Anal 9.6 &I.8 Highest " 12 CARROT ROOT. 2.0 4.9 Average of 10 Analyses. 1.4 4.8 " 5 " byW, 2.5 4.9 " 5 " "ott 0.9 2.1 Lowest percentage i1n 5 Analyi 4.8 6.4 Highest " 5 TURNIP ROOT. 0.7 5.1 Average of 43 Analyses. 1.6 3.0 " 6 " byWt 0.9 6.5 " 5 " "Ani 2.0 5.5' 6 " "Ws 0.0 5.1 " 24 " "Gil 1.2 7.0 " 2 " "oth 0.0 1.5 Lowest percentage in 19 Anal3 3.5 12.8 Highest " 19' . 46.6 18.4 4.8 5.9 0.8 8.3 3.7 9.5 30.2 35.6 2.6 2.4 0.7 3.8 4.1 5.3 51.4 15.1 6.4 5.3 0.6 10.7 8.1 ... 57.6 6.3 3.9 5.5 1.0 13.0 2.9 8.1 49.9 13.9 5.8 9.3 0.9 7.4 4.2 2.8 25.2 5.2 2.1 2.2 0.0 1.9 2.1 11.3 59.2 38.9 12.1 20.2 3.1 13.1 12.3 7.5 37.0 20.7 5.2 10.9 1.0 11.2 6.9 6.6 39.1 20.4 4.8 10.7 1.3 10.3 7.9 8.3 35.0 21.0 5.6 11.0 0.6 12.1 5.8 5.1 17.0 10.1 1.3 6.6 0.0 8.2 3.3 10.9 50.9 34.8 9.1 16.5 2.0 15.0 11.7 8.1 48.6 8.7 2.6 12.1 0.4 10.6 12.3 10.8 46.2 9.6 4.4 9.0 1.2 14.3 11.4 11.8 43.7 12.4 4.7- 10.0 0.8 10.2 12.1 7.5 38.3 13.7 2.9 11.3.,0.5 11.2 14.7 6.9 52.7 6.4 1.7 13.3 0.0 9.2 12.4 7.2 50.6 3.9 2.0 13.9 0.4 16.4 6.3 6.0 26.3 0.0 1.7 5.5 0.0 6.8 2.6 20.9 58.3 20.5 6.4 16.2 1.8 16.9 17.9 FIELD BEET TOPS. 25.1 20.5 10.4 9.8 1.2 5.4 7.2 3.3 17.6 Avera,e of 4Analyses. 17.0 22.6 23.0 9.2 9.2 1.0 5.5 6.2 2.1 21.8 " 3 " by Way 21.8 32.7 13.1 13.9 11.3 1.6 5.0 10.1 6.8 5.1 Analysis by Wolff. 14.0 9.0 13.1 7.5 8.7 0.5 4.7 4.9 1.4 5.1 Lowest percentage in 4Analyt 21.8 32.7 23.9 13.9 11.3 1.6 6.4 10.1 6.8 24.6 Highest " 4 * Etti, Griepenkerl, Herapath, Boussingault. t Bretschneider, Richardson, Fromberg (2), lHenrt COMPOSITION OF THE ASH OF SOME AGRICULTURAL PLANTS AND PRODUCTS, ETC.-[Continuedj. P |C Po- | eSoda. Mag Lim|. oxide cPho8-S7Z Chk l I I o0 Sodh. na. Li ron. poi-c phuric Sii cia. Ash. Acid., .a~~~~~~~~~~~~fh ~ ~ ~ ~ ~ fn. I[I SUGAR BEET TOPS. 21 1.3 7.6 6.5 3.5 4.7 Average of 4Analysesby* 0.7 5.4 4.6 1.5 2.8 Lowest percentage in 4 Analyses. 2.3 9.2 8.3 5.6 7.2l Highest " 4 " CARROT TOPS. 2.0 3.1 8.4 3.7 10.2 Average of 6 Analyses. 2.9 2.0 7.3 5.5 9.3 " 3 " byway & Ogston. 1.1 4.2 9.5 1.9 11.0 " 3 " "' others.t 0.6 1.4 6.9 1.6 2.7 Lowest percentage in 6 Analyses. 4.9 6.4 11.1 8.8 16.2 Highest " 6 TURNIP TOPS. 0.8 6.7 13.3 1.5 8.7 Average of 36 Analyses. 1.9 7.2 9.6 4.6 13.5 6 " byWay & Ogston. 3.3 9.1 8.5 4.0 7.6 " 4 " Wunder. 0.0 6.1 15.2 0.0 7.8 " 24 " "Campbell. 1.6 7.6 10.7 6.0 7.6' 2 " others.$ 0.0 2.0 5.0 0.0 2.5 Lowest percentage in 12 Analyses, exclusive of Campbell's. 5.5 15.1 16.3 9.5 18.9 Highest " 12 " " COTTON STALKS. 38 4 0.6 12.6 11.8. 1.1. Lawrence Smith. Report to Black Oak Ag'l Soc. 1846. 3. 34.9 3.5 3.2 0.7 O. Judd. Proceedings Am. Association of Science, 1852, p. 219. 9.5 18.3 1.7 8.6 0.5T. J. Summer. Proccedings Philadelphia Academy, Dec., 1852. COTTON SEED. 3.3 135.4 1 3.2 I trace 4.8 IT. J. Summer. Analysis imperfect, (loc. cit.) 10.6 | 37.2 |4.1 |trace | 0.5 Higgins & Bickell. Tarner's Cotton Planter's Manual, p. 207. COTTON FIBER. 2.4 6.4 1 4.2 [ 0.3 1 7.8 IHiggins & Bickell, (loc. cit.) eider (2). t Fromberg (2), Bretachneider. $ Namur, Anderson. 0 -A 0 td cn I22.0 22.3 1 8.8 16.2 19.7 16.3 15.2 12.9 11.0 17.8 '29.2 27.2 31.2 19.2 23.2 17.0 19.8 5.0 32.7 1i.2 8.7 22.2 3.6 39.7 15.5 25.3 17.3 6.4 25).7 15.0 7.7 10.9 3.0 23.1 21.3 30.9 29.0 7.5 41.8 10.9 28.1 6.0 2.5' 34.8' 13.0 21.0 12.4 3.2 32.4 15.3 25.2 6.1 5.0 32.8 9.4 30.5 4.2 1.0 37.0 16.3 27.6 7.9 12.7 20.0 9.5 12.1 4.0 1.0 7.9 19.7 37.2 19.9 16.1 39.6 THE ASH OF PLANTS. The composition of the ash of a number of ordinary crops is concisely exhibited in the subjoined general statement. * ]oa. A r~, P hosphor- iflla. Sulihur, C7gorine. nara.. Ysia. li... ia c Acid. - Acid. f..... CEREALS Grain *.... 30 Straw...... 13-27 LEGUMES — Kernel.... 44 Straw...... 2741 ROOT CROPS Roots..... 60 Tops...... 37 GRASSES In flower.. 33 3 46 2 2.5 1 7 5 5-70 2.5 2 7 5 35 1 4 2 7 2539 8 5 26 6- 7 3-9 6-12 8-18 1-4 3-16 10-35 3-8 3 4 8 8 35 4 5 3..Diferent parts of any plant usually exhibit decided differences in the composition of their ash. This fact is made evident by a comparison of the figures of the table above, and is more fully illustrated by the following analyses of the parts of the mature oat-plant, by Arendt, 1 to 6, (Die ffaferpflanze,p. 107,) and Norton, 7 to 9, (Am. Jour. Sci., 2 Ser. 3, 318.) 1 2 3 4 5 6 7 8 9 Lower Middle Upper Lower Upper Ears. Chaff. Husk.Kernel Stem. Stem. Stem. Leaves.Leaves. husked. Potash................81.2 68.3 55.9 36.9 24.8 13.0 p10~ 12.4 Soda.................. 0.4 1.5 1.0 0.9 0.4 0. 10 6 124 3 Magnesia............ 2.1 3.6 3.9 3.8 3.9 8.9 1 2.3 8.6 Lime........... 3.6 5.3 8.6 16.7 17.2 7.3 1 4.3 5.3 Oxide of Iron......1.0 0.0 0.2 2.7 0.5 trace 112 0.3 0.8 Phosphoric acid...... 2.7 1.4 2.7 1.7 1.5 36.5 J 0.6 49.1 Sulphuric acid........ 0.0 1.3 1.1 3.2 7.5 4.9 5.3 4.3 0.0 Silica................ 4.1 9.3 20.4 34.0 41.8 26.0 68.0 74.1 1.8 Chlorine.............. 8.6 11.7 7.4 1.6 2.4 3.8 3.1 1.4 0.2 The results of Arendt and Norton are not in all respects strictly comparable, having been obtained by different methods, but serve well to establish the fact in question. We see from the above figures that the ash of the lower stem consists chiefly of potash, (81 ~i o.) This alkali is predominant throughout the stem, but in the upper parts, where the stem is not covered by the leaf sheaths, silica and lime occur in large quantity. In the ash of the leaves, *Exclusive of husk. 157 12 3 5-12 3-9 6-13 5-17 HOW CROPS GROW. silica, potash, and lime, are the principal ingredients. In the chaff and husk, silica constitutes three-fourths of the ash, while in the grain, phosphoric acid appears as the characteristic ingredient, existing there in connection with a large amount of potash, (32 o[ o,) and considerable magnesia. Chlorine acquires its maximum, (11.7~1,)in the middle stem, but in the kernel is present in small quantity, while sulphuric acid is totally wanting in the lower stem, and most abundant in the upper leaves. Again, the unequal distribution of the ingredients of the ash is exhibited in the leaves of the sugar beet, which have been investigated by Bretschneider, (Hof. Jahresbericht, 4, 89.) This experimenter divided the leaves of 6 sugar beets into 5 series or circles, proceeding from the outer and older leaves inward. He examined each series separately with the following results: II. 25.9 14.4 6.4 19.2 22.3 0.5 4.8 5.6 0.8 From these data we perceive that in the ash of the leaves of the sugar beet, potash and phosphoric acid reg. ularly and rapidly increase in relation to the other ingredients from without inward, while lime and magnesia as rapidly diminish in the same direction. The per cent of the other ingredients, viz., soda, chlorine, oxide of iron, sulphuric acid, and silica, remains nearly invariable throughout. Another illustration is furnished by the following analyses of the ashes of the various parts of the horse-chestnut tree, made by Wolff, (Ackerbau, 2. Auf., 134): 158 ]III. 32.8 15.8 5.8 18.2 13.0 0.6 5.8 5.6 2.7 IV. 37.4 15.0 6.0 15.8 8.9 0.6 8.4 5.2 2.1 . V. 50.3 11.1 6.5 4.7 6.7 0.5 12.7 5.9 1.5 1. Potash................ 18.7 Soda.................. 15.2 Chloride of Sodium... 5.8 Lime................. 24.2 Magnesia............. 24.5 Oxide of Iron......... 1.4 Phosphoric acid....... 3.3 Stilphuric acid........ 5.4 Silica................. 1.5 I THE ASH OF PLA.N'TS. Wood. Leaf-stems. Leaves. Flower-stems. Calyx. 25.7 46.2 27.9 63.6 61.7 42.9 21.7 29.3 9.3 12.3 5.0 3.0 2.6 1.3 5.9 trace 3.8 9.1 3.5 trace 19.2 14.8 22.4 17.1 16.6 2.6 1.0 4.9 0.7 1.7 6.1 12.2 5.1 4.7 2.4 Ripe Fruit. s. Petals. Green Fruit. Kerne. Green Br Shea. Shea. 61.2 58.7 61.7 75.9 54.6 13.6 9.8 11.5 8.6 16.4 3.8 2.4 0.6 1.1 2.4 trace 3.7 1.7 1.0 3.6 17.0 20.8 22.8 5.3 18.6 1.5 0.9 0.2 0.6 0.8 3.8 4.8 2.0 7.6 5.2 4. Similar kinds of plants, and especially the same parts of similar plants, exhibit a close general agreement in the composition of their ashes; while plants which are unlike in their botanical characters are also unlike in the proportions of theirfixed ingredients. The three plants, wheat, rye, and maize, belong, botanically speaking, to the same natural order, graminece, and the ripe kernels yield ashes almost identical in composition. Barley and the oat are also graminaceous plants, and their seeds should give ashes of similar composition. That such is not the case is chiefly due to the fact, that, unlike the wheat, rye, and maize-kernel, the grains of barley and oats are closely invested with a husk, which forms a part of the kernel as ordinarily seen. This husk yields an ash which is rich in silica, and we can only properly compare barley and oats with wheat and rye, when the former are hulled, or the ash of the hulls is taken out of the account. There are varieties of both oats and barley, whose husks separate from the kernel-the so-called naked or skinless oats and naked or skinless barley-and the ashes of these grains agree quite nearly in composition with those of wheat, rye, and maize, as may be seen from the following table: 159 Bark. Potash.............. 12.1 Lime................ 76.8 Magnesia........... 1.7 Sulphuric acid...... trace Phosphoric acid..... 6.0 Silica............... 1.1 Chlorine............ 2.8 Potash.............. 60.7 Lime................ 13.8 Magnesia........... 3.1 Sulphiric acid...... trace Phosphoric acid....19.5 Silica............... 0.7 Chlorine............. 2.8 HOW CROPS GROW. Rye. Average or twenty-ne analyses. 26.8 4.3 11.6 3.9 0.8 45.6 1.9 2.6 0.7 Wheat. Average or seventy-nine analyse.. Potash.........8 3 1.3 Soda............ 3.2 Magnesia........12.3 Lime............ 3.2 Oxide of Iron... 0.7 Phosphoric acid.46.1 Sulphuric acid... 1.2 Silica............ 1.9 Chlorine........ 0.2 By reference to the table, (p. 152,) it will be observed that the pea and bean kernel, together with the allied vetch and lentil, (p. 379,)also nearly agree in ash-composition. So, too, the ashes of the root-crops, turnips, carrots, and beets, exhibit a general similarity of composition, as may be seen in the table, (p. 154-5). The seeds of the oil-bearing plants likewise constitute a group whose members agree in this respect, p. 379. 5. The ash of the same species of plant is more or less variable in composition, according to circumstances. The conditions that have already been noticed as influencing the proportion of ash are in general the same that affect its quality. Of these we may specially notice: a. The stage of growth of the plant. b. The vigor of its development. c. The variety of the plant or the relative development of its parts, and d. The soil or the supplies of food. a. The stage of growth. The facts that the different parts of a plant yield ashes of different composition, and that the different stages of growth are marked by the development of new organs or the unequal expansion of those already formed, are sufficient to sustain the point now in question, and render it needless to cite analytical evidence. In a subsequent chapter, wherein we shall attempt to trace some of the various steps in the progressive 160 Maize. Average of seven analyses. 27.7 4.0 15.0 1.9 1.0 47.1 1.7 2.1 0.1 S 8 oats. Anatlysis by Fr. Schulze. 33.4 11.S 3.6 0.8 46.9 2.4 Bkinsa barley.' Anal,ysis by Fr. Schulze. ,35.9 1.0 13.7 2.9 0.7 45.0 0.7 / THE ASH OF PLANTS. development of the plant, numerous illustrations will be adduced, (p. 214.) b. Vigor of developnment. Arendt, (Die -Zaferpflanze, p. 18,) selected from an oat-field a number of plants in bl(.ssom, and divided them into three parcels-, composed of very vigorous plants; 2, of medium; and, 3, of very weak plants. He analyzed the ashes of each parcel, with results as below: 1 2 3 Silica.....................27.0 39.9 42.0 Sulphuric acid............ 4.8 4.1 5.6 Phosphoric acid.......... 8.2 8.5 8.8 Chlorine................. 6.7 5.8 4.7 Oxide of Iron............. 0.4 0.5 1.0 Lime..................... 6.1 5.4 5.1 Mag-nesia, Potash & Soda.45.3 34.3 30.4 Here we notice that the ash of the weak plants contains 15 per cent less of alkalies, and 15 per cent more of silica, than that of the vigorous ones, while the proportion of the other ingredients is not greatly different. Zoeller, (Liebig's Ernahrung der Vegetabiien, p. 340,) examined the ash of two specimens of clover which grew on the same soil and under similar circumstances, save that one, from being shaded by a tree, was less fully developed than the other. Six weeks after the sowing of the seed, the clover was cut, and gave the following results on partial analysis: haded clover. Unshaded clover. Alkalies................54.9 36.2 Lime...................14.2 22.8 Silica................... 5.5 12.4 c. The variety of the plant or the relative development of its parts must obviously influence the composition of the ash taken as a whole, since the parts themselves are unlike in composition. Herapath, (Qu. Jour. Chem. Soc., II, p. 20,) analyzed the ashes of the tubers of five varieties of potatoes, raised on the same soil and under precisely similar circumstances. His results are as follows: 161 HOW CROPS GI?OW. ap. Forty-fod. .0 62.1 - 2.5 .0 3.3 .1 3.5 .4 20.7 .5 7.9 aures included, proportions of a considerable etermines the opment of its ptent, includes rnge of weight hen grown on , inferior soil otland, for the c., 1857-9, p. stricts weighricts it was as 24 pounds per husk, and an of good oats. 107,) has pub, the yield berom the same sas 64 bushels as follows: )3,) has anal Wolff, (Jour. far Prakt. Chem., 52, p. 10 * Thickly covering with sediment from muddly tide-water. 162 II i I. I i THE ASH OF PLANTS. ysed the ashes of several plants, cultivated in a poor soil, with the addition of various mineral fertilizers. The influence of the added substances on the composition of the plant is very striking. The following figures comprise his results on the ash of buckwheat straw, which grew on the unmanured soil, and on the same, after application of the substances specified below: 4 5 6 Carbonate Sulphate Carbonate of of of .potash. magnesia. ime. 40.5 28.2 23.9 3.1 6.9 9.7 3.8 3.4 1.7 11.6 14.1 18.6 1.4 4.7 4.2 4.3 7.1 3.5 8.9 10.9 10.0 22.2 20.0 23.2 4.2 4.8 5.2 100.0 100.0 100.0 nured. Potash............... 31.7 Chlorideofpotassium. 7.4 Chlorideof sodium.... 4.6 Lim................ 15.7 Magnesia.............. 1.7 Sulphuric acid......... 4.7 Phosphoric acid....... 10.3 Carbonic acid.........20.4 Silica................. 3.6 100.0 It is seen from these figures that all the applications employed in this experiment exerted a manifest influence, and, in general, the substance added, or at least one of its ingredients, is found in the plant in increased quantity. In 2, chlorine, but not sodium; in 3 and 4, potash; in 5, sulphuric acid and magnesia, and in 6, lime, are present in larger proportion than in the ash from the unmanured soil. 6. What is the Normal Composition of the Ash of a Plant?. It is evident from the foregoing facts and considerations that to pronounce upon the normal composition of the ash of a plant, or, in other words, to ascertain what ash-ingredients and what proportions of them are proper to any species of plant or to any of its parts, is a matter of much difficulty and uncertainty. The best that can be done is to adopt the average of a great number of trustworthy analyses as the approximate expression of ash-composition. From such data, however, we are still unable to decide what are the absolutely es 163 2 3 C ~ 2itrate of of sodium. potash. 21.6 39.6 26.9 0.8 3.0 3.2 14.0 12.8 1.9 3.3 2.8 2.7 9.5 6.5 16.1 27.1 4.2 4.2 100.0 100.0 HOW CROPS GROW. sential, and what are really accidental ingredients, or what amount of any given ingredient is essential, and to what extent it is accidental. Wolff, who appears to have first suggested that a' part of the ash of plants may be accidental, endeavored to approach a solution of this question, by comparing together the ashes of samples of the same plant, cultivated under the same circumstances in all respects, save that they were supplied with unequal quantities of readily available ash-ingredients. The analyses of the ashes of buckwheat-stems, just quoted, belong to this investigation. Wolff showed that, by assuming the presence in each specimen of buckwheat-straw of a certain excess of certain ingredients, and deducting the same from the total ash, the residuary ingredients closely approximated in their proportions to those observed in the crop which grew in an unmanured soil. The analyses just quoted, (p. 163,) are here "corrected" in this manner, by the subtraction of a certain per cent of those ingredients which in each case were furnished to the plant by the fertilizer applied to it. The numbers of the analyses correspond with those on the previous page. 1 2 3 4 5 6 20p. c. 20p. c. 25p. c. 8.5p. c. 16.6p. c. Chloride Carbonate Carbonate Sulphate Carbonates After deductmon o f of of oflme and of........... Notang. poI um.a pot ag. magnesia. Potash............ 31.7 27.0 32.5 33.5 30.6 28.0 Chloride of potassium. 7.4 9.1 1.0 3.9 7.4 11.3 Chlorideofsodium.... 4.6 3.8 4.0 4.7 3.7 1.9 Lime..................15.7 17.3 16.0 14.5 15.3 14.6 Magnesia.............. 1.7 2.4 4.1 1.7 2.3 2.9 Sulphuricacid........ 4.7 3.5 3.4 5.4 2.1 4.1 Phosphoric acid.......10.3 11.7 8.1 11.2 11.8 11.7 Carbonic acid.........20.4 20.1 25.9 19.8 21.6 19.3 Silica................. 3.6 5.2 5.2 5.3 5.2 6.1 100.0 100.0 100.0 100.0 100 0 100.0 The correspondence in the above analyses thus "corrected," already tolerably close, might, as Wolff remarks, (loc. cit.) be made much more exact by a further correction, in which the quantities of the two most variable in 164 ., THE ASH OF PLANTS. gredients, viz. chlorine and sulphuric acid, should be reduced to uniformity, and the analyses then be recalculated to per cent. In the first place, however, we are not warranted in assuming that the "excess" of chloride of potassium, carbonate of potash, etc., deducted in the above analyses respectively, was all accidental and unnecessary to the plant, for, under the influence of an increased amount of a nutritive ingredient, the plant may not only mechanically contain more, but may chemically employ more in the vegetative processes. It is well proved that vegetation grown under the influence of large supplies of nitrogenous manures, contains an increased proportion of nitrogen in the truly assimilated state of albumin, gluten, etc. The same may be equally true of the various ash-ingredients. Again, in the second place, we cannot say that in any instance the minimum quantity of any ingredient necessary to the vegetative act is present, and no more. It must be remarked that these great variations are only seen when we compare together plants produced on poor 8oils, i. e. on those which are relatively deficient in some one or several ingredients. If a fertile soil had been employed to support the buckwheat plants in these trials, we should doubtless have had a very different result. In 1859, Metzdorf, (Wilda's Centralblatt, 1862, 2, p. 367,) analysed the ashes of eight samples of the red-onion potato, grown on the same field in Silesia, but differently manured. Without copying the analyses, we may state some of the most striking results. The extreme range of variation in potash was 51 per cent. The ash containing the highest percentage of potash was not, however, obtained from potatoes that had been manured with 50 pounds of this substance, but from a parcel to which had been applied a poudrette containing less than 3 pounds of potash for the quantity usedc 165 HfOW CROPS GROW. The unmanured potatoes were relatively the richest in lime, phosphoric acid, and sulphuric acid, although several parcels were copiously treated with manures containing considerable quantities of these substances. These facts are of great interest in reference to the theory of the action of manures. 7. To what Extent is each Ash-ingredient Essential, and how far may it be Accidental? Before the art of chemical analysis had arrived at much perfection, it was believed by many men of science, that the ashes of the plant were either unessential to growth, or else were the products of growth-were generated by the plant. Since the substances found in ashes are universally distributed over the earth's surface, and are invariably present in all soils, it is not possible by analysis of the ash of plants growing under natural conditions, to decide whether any or several of their ingredients are indispensable to vegetative life. For this purpose it is necessary to institute experimental inquiries, and these have been prosecuted with great pains-taking, though not with results that are in all respects satisfactory. Experiments in Artificial Soils.-The. Prince SalmHorstmar, of Germany, has been a most laborious student of this question. His plan of experiment was the following: the seeds of a plant were sown in a soil-like mnedium, (sugar-charcoal, pulverized quartz, purified sand,) which was as thoroughly as possible freed from the substance whose special influence on growth was the subject of study. All other substances presumably necessary, and all the usual external conditions of growth, (light, warmth, moisture, etc.,) were supplied. The results of 195 trials thus made with oats, wheat, barley, and colza, subjected to the influence of a great variety of artificial mixtures, have been described, the most important of which will shortly be given. 166 9 II THE ASH OF PLANITS. Experiments in Solutions.-Water-Culture.-Sachs, W. Knop, Stohmann, Nobbe, Siegert, and others have likewise studied this subject. Their method was like that of Prince Salm-Horstmar, except that the plants were made to germinate and grow independently of any soil; and, throughout the experiment, had their roots immersed in water, containing in solution or suspension the substances whose action was to be observed. Water- Culture has recently contributed so much to our knowledge of the conditions of vegetable growth', that some account of the mode of conducting it may be properly given in this place. Cause a number of seeds of the plant it is desired to experiment upon to germinate in moist cotton or coarse sand, and when the roots have become an inch or two in length, select the strongest seedlings, and support them, so that the roots shall be immersed in water, while the seeds themselves shall be just above the surface of the liquid. For this purpose, in case of a single maize plant, for example, provide a r quart cylinder or bottle, with a wide mouth, to which a cork is fitted, as in Fig. 22. Cut a vertical notch in the cork to its center, and fix therein the stem of the seedling by packing with cotton. The cork thus serves as a support of the plant. Fill the jar with pure water to such a height that when the cork is brought to its, place, the seed, S, shall be a little above the liquid. If the endosperm Fig. 22. or cotyledons dip into the water, they will speedily mould and rot; they require, however, to be kept in 167 HOW CROPS GROW. a moist atmosphere. Thus arranged, suitable warmth, ventilation, and illumination, alone are requisite to continue the growth until the nutriment of the seed is nearly exhausted. As regards illumination, this should be as full as possible, for the foliage; but the roots should be protected from it, by enclosing the vessel in a shield of black paper, as, otherwise, minute parasitic alga would in time develop upon the roots, and disturb their functions. For the first days of growth, pure distilled water may advantageously surround the roots, but when the first green leaf appears, they should be placed in the solution whose nutritive power is to be tested. The temperature should be properly proportioned to the light, in imitation of what is observed in the skillful management of conservatory or house-plants. The experimenter should first learn how to produce large and well-developed plants, by aid of an appropriate liquid, before attempting the investigation of other problems. For this purpose, a solution or mixture must be prepared, containing in proper proportions all that the plant requires, save what it can derive from the atmosphere. The recent experience of Nobbe & Siegert, Wolff, and others, supplies valuable information on this point. Prof. Wolff has obtained striking results with a variety of plants in using a solution made essentially as follows: Place 20 grams, (300 grains,) of the fine powder of wellburned bones with a half pint of water in a large glass flask, heat to boiling, and add nitric acid cautiously in quantity just sufficient to dissolve the bone-ash. In order to remove any injurious excess of nitric acid, pour into the hot liquid, solution of carbonate of potash until a slight permanent turbidity is produced; then add 11 grams, (180 grains,) of nitrate of potash, 7 grams, (107 grains,) of crystallized sulphate of magnesia, and 3 grams, (60 grains,) of chloride of potassium, with water enough to make the solution up to the bulk of one liter, (or quart.) Mix 30 168 II i e I THE ASH OF PLANTS. cubic cent., (one fluid ounce,) of this liquid with a liter, (or quart,) of water and a single drop of strong solution of sulphate of iron, and employ this diluted solution to feed the plant. Wolff's solution, thus prepared, contained in 1000 parts as follows, exclusive of iron: - 8.234 - 10.370 - 9.123 - - 1.403 - 2.254 - - 0.885 - 29.703 - - 61.972 938.028 1000. Solid Matters - - Water - - -. This solution was diluted to a liquid containing but one part of solid matters to 1000 or 2000 parts of water. The solution should be changed every week, and as the plants acquire greater size, their roots should be transferred to a larger vessel, filled with solution of the same strength. It is important that the water which escapes from the jar by evaporation and by transpiration through the plant, should be daily or oftener replaced, by filling it with pure water up to the original level. The solution, whose preparation has been described, may be turbid from the separation of a little white sulphate of lime before the last dilution, as well as from the precipitation of phosphate of iron on adding sulphate of iron. The former deposit may be dissolved, though this is not needful; the latter will not dissolve, and should be occasionally put into suspension by stirring the liquid. When the plant is half grown, further addition of iron is unnecessary. In this manner, and with this solution, Wolff produced 8 169 HOW CROPS GROW. a maize plant, five and three quarters feet high, and equal in every respect, as regards size, to plants from similar seed, cultivated in the field. The ears were not, however, fully developed when the experiment was interrupted by the plant becoming unhealthy. With the oat his success was better. Four plants were brought to maturity, having 46 stems and 1535 well-devel oped seeds. (IV. St., VIII, 190-215.) In similar experiments, Nobbe obtained buckwheat plants, six to seven feet high, bearing three hundred plump and perfect seeds, and barley stools with twenty grainbearing stalks. (FVs. St., VII, 72.) In water-culture, the composition of the solution is suffering continual alteration, firom the fact that the plant makes, to a certain extent, a selection of the matters presented to it, and does not necessarily absorb them in the proportions in which they originally existed. In this way, disturbances arise which impede or become fatal to growth. In the early experiments of Sachs and Kntop, in 1860, they frequently observed that their solutions suddenly acquired the odor of sulphydric acid, and black sulphide of iron formed upon the roots, in consequence of which they were shortly destroyed. This reduction of a sulphate to a sul phide takes place only in an alkaline liquid, and Stohmann was the first to notice that an acid liquid might be made alkaline by the action of living roots. The plant, in fact, has the power to' decompose salts, and by appropriat ing the acids more abundantly than the bases, the latter accumulate in the solution in the free state, or as carbon ates with alkaline properties. To prevent the reduction of sulphates, the solution must be kept slightly acid, best by addition of a very little firee nitric acid, and if the roots blacken, they must be washed with a dilute acid, and, after rinsing with water, must be transferred to a fresh solution. On the other hand, Kiihn has shown that when chloride 170 i I THE ASH OF PLANTS. of ammonium is employed to supply maize with nitrogen, this salt is decomposed, its ammonia assimilated, and its chlorine, which the plant cannot use, accumulates in the solution in the form of chlorhydric acid, to such an extent as to prove fatal to the plant, (Benneberg's Journa7, 1864, pp. 116 and 135.) Such disturbances are avoided by employing large volumes of solution, and by frequently renewing them. The concentration of the solution of is by no means a matter of indifference. While certain aquatic plants, as sea-weeds, are naturally adapted to strong saline solutions, agricultural land-plants rarely succeed well in water-culture, when the liquid contains more than2 [000 of solid matters, and will thrive in considerably weaker solutions. Simple well-water is often rich enough in plant-food to nourish vegetation perfectly, provided it be renewed sufficiently often. Sachs' earliest experiments were made with well-water. Birner and Lucanus, in 1864, (Vs. St., VIII, 154,) raised oat-plants in well-water, which in respect to entire weight were more than half as heavy as plants that grew simul taneously in garden soil, and, as regards seed-production, fully equalled the latter. The well-water employed, contained in 100.000 parts: Potash 2.10 Lime - - - - - - 15.10 Magnesia - - - - - 1.50 Phosphoric acid - - - - 0.16 Sulphuric acid - - - - 7.50 Nitric acid.. - - - 6.00 Silica, Chlorine, Oxide of iron - - traces Solid Matters -..- 32.36 Water - - - - - - - - 99,967.64 100,000 Nobbe, ( Vs. St., VIII, 337,) found that in a solution containing but l100o of solid matters, which was continually 171 HOW CROPS GROW. renewed, barley made no progress beyond gel mination, alnd a buckwheat plant, which at first grew rapidly, was soon arrested in its development, and yielded but a few ripe seeds, and but 1.746 grm. of total dry matter. While water-culture does not provide all the normal conditions of growth-the soil having important functions that cannot be enacted by any liquid medium-it is a method of producing highly-developed plants, under circumstances which admit of accurate control and great variety of alteration, and is, therefore, of the utmost value in vegetable physiology. It has taught important facts which no other means of study could reveal, and promises to enrich our knowledge in a still more eminent degree. Potash, Lime, Magnesia, Phosphoric Acid, and Sulphuric Acid, are absolutely necessary for the life of Agricultural Plants, as is demonstrated by all the experiments hitherto made for studying their influence. It is not needful to recount here the evidence to this effect that is furnished by the investigations of SalmHorstmar, Sachs, Knop, and others. (See, especially, Birner & Lucanus, VFs. St., VIII, 128-161.) Is Soda Essential for Agricultural Plants? This question has occasioned much discussion. A glance at the table of ash-analyses, (pp. 150-56,) will show that the range of variation is very great as regards this alkali Among the older analysts, Bichonll found in the ash of the pea 13, in that of the bean 19, in that of rye 19, in that of wheat 27 per cent of soda. IIerapath found 15 per cent of this substance in wheat-ash, and 20 per cent in ash of lye. Brewer found 13 per cent in the ash of maize. la a few other analyses of the grains, we find similar high percentages. In most of the analyses, however, soda is present in much smaller quantity. The average in the ashes of the grains is less than 3 per cent, and in not a few of the analyses it is entirely wanting. 172 II i THE ASH OF PLANTS. In the older analyses of other classes of agricultural plants, especially in root crops, similarly great variations occur. Some uncertainty exists as to these older data, for the reason that the estimation of soda by the processes customarily employed is liable to great inaccuracy, especially with the inexperienced analyst. On the one hand, it is not easy, (or has not been easy until lately,) to detect, much less to estimate, minute traces of soda, when mixed with much potash; while on the other hand, soda, if present to the extent of a per cent or more, is very liable to be estimated too high. It has therefore been doubted if these high percentages in the ash of grains are correct. Again, furthermore, the processes formerly employed for preparing the ash of plants for analysis were such as, by too elevated and prolonged heating, might easily occasion a partial or total expulsion of soda from a material which properly should contain it, and we may hence be in doubt whether the older analyses, in which soda is not mention ed, are to be altogether depended upon. The later analyses, especially those by Bibra, Zoeller, Arendt, Bretschneider, Ritthausen, and others, who have employed well-selected and carefully-cleaned materials for their investigations, and who have been aware of all the various sources of error incident to such analyses, must therefore be appealed to in this discussion. From these recent analyses we are led to precisely the same conclusions as were warranted by the older investigations. Here fol. lows a statement of the range of percentages of soda in the ash of several field crops, according to the newest analyses: Ash of Wheat kernel, none, Bibra, to 501o Bibra. " " Potato tuber, none, I CamtedrOlnff, 4010 Wolff. noe,Mtzdorff, 4010~iba ""Barley0kernel 101 Bibra, 4 I Vebtmann. Barley kernel 2010o Zoeller, 701o Zoeller. ,Sugar beet, t4.701o Ritthausen, "29.8010 Ritthausen. S~ugar e 5.7~010 Bretschneider" 16.60 o Bretschneider. '' Turnip root, 7.7~[0o Anderson, " 17.1o 0 Anderson 17~3 HOW CROPS GROW. Although, as just indicated, soda has been found want ing in the wheat kernel and in potato tubers, in some in stances, it is not certain that it was absent from other parts of the same plants, nor has it been proved, so far as we know, that soda is wanting in any entireplant which has grown on a natural soil. Weinhold found in the ash of the stem and leaves of the common live-for-ever, (Sedum telephium,) no trace of soda detectable by ordinary means; while in the ash of the roots of the same plant, there occurred 1.8 per cent of this substance. (Vs. St., IV, p. 190.) It is possible, then, that, in the above instances, soda really existed in the plants, though not in those parts which were subjected to analysis. It should be added that in ordinary analyses, where soda is stated to be absent, it is simply implied that it is present in unweighable quantity,* if at all, while in reality a minute amount may be present in all such cases.t The grand result of all the analytical investigations hitherto made, with regard to cultivated agricultural plants, then, is that soda is an extremely variable ingredient of the ash of plants, and thotugh generally present in some proportion, and often in large proportion, has been observed to be absent in weighable qcuantity in the seeds of grains and in the tubers of potatoes. Salm-Horstmar, Stohmann, Knop, and Nobbe & Sicgert, have contributed certain synthetical data that bear on the question before us. The investigations of Salm-Horstmar were made with the greatest nicety, and especial attention was bestowed on the influence of very minute quantities of the various * Unweig,hable quantities are designated as "trace" or "traces. t The newly discovered methods of spectral analysis, by which 9rl of a grain of soda may be detected, have demonstrated that this element is so universally distributed that it is next to impossible to find or make anything that is free from it. 174 I I... e t THE ASH OF PLANTS. substances employed. He gives as the result of numerous experiments, that for wheat, oats, and barley, in the early vegetative stages of growth, soda, while advantageous, as not essential, but that for the perfection of fruit an appreciable though minute quantity of this substance is in. dispensable. ( Versuche und Resultate fiber die Ncthrunzg der Pfanzen, pp. 12, 27, 29, 36.) Stohmann's single experiment led to the similar concltusion, that maize may dispense with soda in the earlier stages of its growth, but requires it for a full development. (Henneberg's Jour. flor Landwirthschaft, 1862, p. 25.) Knop, on the other hand, succeeded in bringing the maize plant to full perfection of parts, if not of size, in a solution which was intended and asserted to contain no soda. (Vs. St., III, p. 301.) Nobbe & Siegert came to the same results in similar trials with buckwheat. (Vs. St., IV, p. 339.) The experiments of Knop, and of Nobbe & Siegert, while they prove that much soda is not needful to maize and buckwheat, do not, however, satisfactorily demonstrate that a trace of soda is not necessary, because the solutions in which the roots of the plants were immersed stood for months in glass vessels, and could scarcely fail to dissolve some soda from the glass. Again, slight impurity of the substances which were employed in making the solution could scarcely be avoided without extraordinary precautions, and, finally, the seeds of these plants might originally have contained enough soda to supply this substance to the plants in appreciable quantity. To sum up, it appears from all the facts before us: 1. That soda is never totally absent from plants, but that, 2. If indispensable, but a minute amount of it is requisitc e 3. That the foliage and succulent portions of the plant 175 IHOW CROPS GROW. may include a considerable amount of soda that is not near essary to the plant, that is, in other words, accidental.* Can Soda replace Potash?-The close similarity of pot ash and soda, and the variable quantities in which the latter especially is met with in plants, has led to the assutimption that one of these alkalies can take the place of the other. Salm-Horstmar, and, more recently, Knop & Schreber, have demonstrated that soda cannot entirely take the place of potash-in other words, potash is indispensable to plant life. Cameron concludes from a series of experiments, which it is unnecessary to describe, that soda can partially replace potash. A partial replacement of this kind would appear to be indicated by many facts. Thus, Herapath has made two analyses of asparagus, one of the wild, the other of the cultivated plant, both gathered in flower. The former was rich in soda, the latter almost destitute of this substance, but contained correspondingly more potash. Two analyses of the ash of the beet, one by Wolff, (1.,) the other by Way, (2.,) exhibit similar differences: Aspaagbus. Field Beet. Wild. Cltivated. 1. 2. Potash................18.8 50.5 57.0 25.1 Soda..................16.2 trace 7.3 34.1 Lime................. 28.1 21.3 5.8 2.2 Magnesia.............. 1.5 - 4.0 2.1 Chlorine...............16.5 8.3 4.9 34.8 Sulplhiuric acid......... 9.2 4.5 3.5 3.6 Phosphoric acid.......12.8 12.4 12.9 1.9 Silica.................. 1.0 3.7 3.7 1.7 These results go to shot-it being assumed that only a very minute amount of soda, if any, is absolutely necessary to plant-life —that the soda which appears to replace potash is accidental, and that the replaced potash is acci * Soda appears to be essential o animal life since all the food of animals is derived, indirectly at least, from the vegetable kingdom, it is a wise provision that soda is contained in, if it be not indispensable to plants. 176 I THE ASH OF PLANTS. dtental also, or in excess above what is really needed by the plant, and leaves us to infer that the quantity of these bodies absorbed, depends to some extent on the composition of the soil, and is to the same degree independent of the wants of vegetation. Alkalies in Strand and Marine Plants.-The above conclusions cannot as yet be accepted in case of plants which grow only near or in salt water. Asparagus, the beet and carrot, though native to saline shores, are easily capable of inland cultivation, and indeed grow wild in total or comparative absence of soda-compounds.* The common saltworts, Salsola, and the samphire, Salicornia, are plants, which, unlike those just mentioned, never stray inland. Gobel, who has analyzed these plants as occurring on the Caspian steppes, found in the soluble part of the ash of the Saalsola brachiata, 4.8 per cent of potash, and 30.3 per cent of soda, and in the Salicornia herbacea, 2.6 per cent of potash and 36.4 per cent of soda; the soda constituting in the first instance no less than 11 15 and in the latter ~I1'4 of the entire weight, not of the ash, but of the air-dry plant. Potash is never absent in these forms of vegetation. (Agricultur-Chemie, 3e Auf., p. 66.) According to Cadet, (Liebig's Ernahrung der FVeg., p. 100,) the seeds of the Salsola kali, sown in common garden soil, gave a plant which contained both soda and potash; from the seeds of this, sown also in garden soil, grew plants in which only potash-salts with traces of soda could be found. Another class of plants-the sea-weeds, (algae,)-derive their nutriment exclusively from the sea-water in which they are immersed. Though the quantity of potash in seawater is but 1,0 that of the soda, it is yet a fact, as shown by the analyses of Forchhammer, (Jour fur Prakt. Chem., * This is not, indeed, proved by analysis, in case of the carrot, but is doubtless true. 8* 177 HOW CROPS GROW. 36, p. 391,) and Anderson, (Trans. High. and Ag. Soc., 1855-7, p. 349,) that the ash of sea-weeds is, in general, as rich, or even richer, in potash than in soda. In 14 analyses, by Forchhammer, the average amount of soda in the dry weed was 3.1 per cent; that of potash 2.5 per cent. In Anderson's results, the percentage of potash i invariably higher than that of soda.* Analogy with land-plants would lead to the inference that the soda of the sea-weeds is in a great degree accidental, although, necessarily, special investigations are required to establish a point like this Oxide of Iron is essential to plants.-It is abundantly proved that a minute quantity of oxide of iron, Fe, 0,, is essential to growth, though the agricultural plant may be perfect if provided with so little as to be discoverable in its ash only by sensitive tests. Accord ing to Salm-Horstmar, theprotoxide of iron is indispensable to the colza plant. ( Versuche, etc., p. 35.) Knop asserts that maize, which refuses to grow in entire absence of oxide of iron, flourishes when the phosphate of iron, which is exceedingly insoluble, is simply suspended in the solution that bathes its roots for the first four weeks only of the growth of the plant. ( VFs. St. V, p. 101.) We find that the quantity of oxide of iron given in the analyses of the ashes of agricultural plants is small, being usually less than one per cent. Here, too, considerable variations are observed. In the analyses of the seeds of cereals, oxide of iron ranges from an unweighable trace to 2 and even 30 Io. In root crops it has been found as high as 5~1 0. Kekule found in the ash of gluten firom wheat 7.1~0o of oxide of iron. (Jahres bericht der Chem., 1851, p. 715.) Schulz-Fleeth found 17.5~010 in the ash of the albumin from the juice of the * Doubtless due to the fact that the material used by Anderson was freed by washing from adhering common salt. 178 .1 II f THE ASH OF PLANTS. potato tuber. The proportion of ash is, however, so small that in case of potato-albumin, the oxide of iron amounts to but 0.12 per cent of the dry substance. (.Der Rationelle Ackerbau, p. 82.) In the wood, and especially in the bark of trees, oxide of iron often exists to the extent of 5-10~ [0. The largest percentages have been found in aquatic plants. In the ash of the duck-meat, (Lemna trisulca,) Liebig found 7.40 o. Gorup-Besanez found in the ash of the leaves of the Trapa natans 29.60 1o, and in the ash of the fruit-envelope of the same plant 68.6010. (Ann. Ch. Ph., 118. p. 223.) Probably much of the iron of agricultural and land plants is accidental. In case of the Trapa natans, we cannot suppose all the oxide of iron to be essential, because the larger share of it exists in the tissues as a brown powder, which may be extracted by acids, and has the appearance of having accumulated there mechanically. Doubtless a portion of the oxide of iron encountered in analyses of agricultural vegetation has never once existed within the vegetable tissues, but comes from the soil which adheres with great tenacity to all parts of plants. Oxide of Manganese, Mn3 O4, is unessential to Agricultural Plants.-This oxide is commonly less abundant than oxide of iron, and is often, if not usually, as good as wanting in agricultural plants. It generally accompanies oxide of iron where the latter occurs in considerable quantity. Thus, in the ash of Trapa, it was found to the extent of 7.5-14.7~'10. Sometimes it is found in much larger quantity than oxide of iron; e.g., C. Fresenius found 11.20 I0 of oxide of manganese in ash of leaves of the red beech, (Fagus sylvatica,) that contained but 10 1o of oxide of iron. In the ash of oak leaves, ( Quercus robur,) Neubauer found, of the former 6.6, of the latter but 1.2~ 0. In ash of the wood of the larch, (Larix Earopea,) Bo6ttinger found 13.50 Io Mn, 0, and 4.201~ Fe, 0O, and in 179 HOW CROPS GROW. ash of wood of Pinus sylvestris 18.21~ l IMn 04, and 3.5'1, Fe, O. In ash of the seed of colza, Nitzsch found 16.1~1 Mn3 0,, and 5.5 Fe2 O3. In case of land plants, these high percentages are accidental, and specimens of most of the plants just named have been analyzed, which were free from all but traces of oxide of manganese. Salm-Horstmar concluded from his experiments that oxide of manganese is indispensable to vegetation. Sachs, Knop, and most other experimenters in water-culture, make no mention of this substance in the mixtures, which in their hands have served for the more or less perfect development of a variety of agricultural plants. Birner & Lucanus have demonstrated that manganese is not needful to the oat-plant, and cannot take the place of iron. (Vs. St., VIII, p. 43.) Is Chlorine indispensable to Crops?-What has been written of the occurrence of soda in plants appears to apply in most respects equally well to chlorine. In nature, soda, or rather sodium, is generally associated with chlorine as common salt. It is most probably in this form that the two substances usually enter the plant, and in the majority of cases, when one of them is present in large quantity, the other exists in correspond. ing quantity. Less commonly, the chlorine of plants is in combination with potassium exclusively. Chlorine is doubtless never absent from the perfect agricultural plant, as produced under natural conditions, though its quantity is liable to great variation, and is often very small-so small as to be overlooked, except by the careful analyst. In many analyses of grain, chlorine is not mentioned. Its absence, in many cases, is due, without doubt, to the fact that chlorine is readily dissipated from the ash of substances rich in phosphoric, silicic, or sulphuric acids, on prolonged exposure to a high temperature. In the later analyses, in which the vegetable substance, instead of being at once burned to ashes, at a high red heat, is 180 i i II I THE ASH OF PLANTS. first charred at a heat of low redness, and then leached with water, which dissolves the chlorides, and separates them from the unburned carbon and other matters, chlorine is invariably mentioned. In the tables of analyses, the averages of chlorine are undeniably too low. This is especially true of the grains. The average of chlorine in the 26 analyses of wheat by Way & Ogston, p. 150, is but 0.080 Io, it not being found at all in the ash of 21 samples. In Zoeller's later analyses, chlorine is found in every instance, and averages 0.70 o1. Weber's analysis, as compared with the others, would indicate a considerable range of variability. Weber extracted the charred ash with water, and found 60 10 of chlorine, which is six times as much as is given in any other recorded analysis of the wheat kernel. This result is in all probability erroneous. Like soda, chlorine is particularly abundant in the stems and leaves of those kinds of vegetation which grow in soils or other media containing much common salt. It accompanies soda in strand and marine plants, and, in general, the content of chlorine of any plant may be largely increased or diminished by supplying it to, or withholding it from the roots. As to the indispensableness of chlorine, we have somewhat conflicting data. Salm-lHorstmar concludes that a trace of it is needful to the wheat plant, though many of his experiments in reference to the importance of this element he himself regards as unsatisfactory. Nobbe & Siegert, who have made an elaborate investigation on the nutritive relations of chlorine to buckwheat, were led to conclude that while the stems and foliage of this plant are able to attain a considerable development in the absence of chlorine, (the minute amount in the seed itself excepted,) presence of chlorine is essential to the perfection of the kernel. On the other hand, Knop excludes chlorine from the 181 HOW CROPS GROW. list of necessary ingredients of maize, and from not yet fully described experiments doubts that it is necessary for buckwheat. Leydhecker, in a more recent investigation, has come to the same conclusions as Nobbe & Siegert, regarding the indispensableness of chlorine to the perfection of buckwheat. (FVs. St., VIII, 177.) From a series of experiments in water-culture, Birner & Lucanus, (Vs. St., VIII, 160,) conclude that chlorine is not indispensable to the oat-plant, and has no specific effect on the production of its fruit. Chloride of potassium increased the weight of the crop, chloride of sodium gave a larger development of foliage and stemn, chloride of magnesium was positively deleterious, under the conditions of their trials. Lucanus, ( F. St., VII, 363-71,) raised clover by water-culture without chlorine, the crop, (dry,) weighing in the most successful experiments 240 times as much as the seed. Addition of chlorine gave no better result. Nobbe, (notes to above paper,) has produced normally developed vetch and pea plants, but only in solutions containing chlorine. Knop, still more recently, (Lehrbuch der Agricultur-Chemie, p. 615,) gives his reasons for not crediting the justness of the conclusions of Nobbe & Siegert and Leydhecker. Until further more decisive results are reached, we are warranted in adopting, with regard to chlorine as related to agriculturalplants, the following conclusions, viz.: 1. Chlorine is never totally absent. 2. If indispensable, but a minute amount is requisite in case of the cereals and clover. 3. Buckwheat, vetches, and perhaps peas, require a not inconsiderable amount of chlorine for full development. 4. The foliage and succulent parts may include a con siderable quantity of chlorine that is not indispensable to the life of the plant. 182 I THE ASH OF PLANTS. Necessity of Chlorine for Strand Plants.-A single observation of Wiegmann and Polstorf, (Preisschrift,) indicates that Salsola kali requires chlorine, though whether it be united to potassium or sodium is indifferent. These experimenters transplanted young salt-worts into a pot of garden soil which contained but traces of chlorine, and watered them with a weak solution of chloride of potassium. The plants grew most luxuriantly blossomed, and completely filled the pot. They were then put out into the earth, without receiving further applications of chlorine-compounds, but the next year they became unhealthy, and perished at the time of blossoming. Silica is not indispensable to Crops.-The numerous analyses we now possess indicate that this substance is always present in the ash of all parts of agricultural plants, when they grow in t natural soils. In the ash of the wood of trees, it usually ranges from 1 to 3~1o, but is often found to the extent of 10-20~01, or even 30~1 0, especially in the pine. In leaves, it is usually more abundant than in stems. The ash of turnip-leaves contains 3-10~I o; of tobacco-leaves, 5-18 l10; of the oat, 1158~ 01. (Arendt, Norton.) In ash of lettuce, 200 Io; of beech leaves, 26~10; in those of oak, 31010 have been observed. (Wicke, Henneberg's Jour., 1862, p. 156.) The bark or cuticle of many plants contains an extraordinary amount of silica. The Cauto tree, of South America, (Hirtella silicea,) is most remarkable in this respect. Its bark is very firm and harsh, and is difficult to cut, having the texture of soft sandstone. In Trinidad, the natives mix its ashes with clay in making pottery. The bark of the Cauto yields 34 10o of ash, and of this 96010 is silica. (Wicke, Henneberg's Jour., 1862, p. 143.) Another plant, remarkable for its content of silica, is the bamboo. The ash of the rind contains 70~10, and in. the joints of the stem are often found concretions of silica, re sembling flint-the so-called Tabashir. 183 HOW CROPS GROW. The ash of the common scouring rush, (Eguisetum Aye. male,) has been found to contain 97.5~0 l of silica. The straw of the cereal grains, and the stems and leaves of grasses, both belonging to the botanical family Graminece, are specially characterized by a large content of silica, ranging from 40 to 70O1o. The sedge and rush families likewise contain much of this substance. The position of silica in the plant would appear, from the percentages above quoted, to be, in general, at the surface. Although it is found in all parts of the plant, yet the cuticle is usually richest, and this is especially true in cases where the content of silica is large. Davy, in 1799, drew attention to the deposition of silica in the cuticle, and advanced the idea that it serves the plant an office of sup port similar to that enacted in animals by the bones. In the ash of the pine, (Pinus sylvestris,) Wittstein has obtained results which indicate that the age of wood or bark greatly influences the content of silica. Hie found in Wood of a tree, 220 years old, 32.501c " "".170 " " 24.1 " ""135 " " 15.1, and in Bark' " " " 220 " " 30.3 "~ "0 " " 170 " " 14.4 " a " "135 " " 11.9 In the ash of the straw of the oat, Arendt found the percentage of silica to increase as the plant approached maturity. So the leaves of forest trees, which in autumn are rich in silica, are nearly destitute of this substance in spring time. Silica accumulates then, in general, in the older and less active parts of the plant, whether these be external or internal, and is relatively deficient in the younger and really growing portions. This rule is not without exceptions. Thus, the chaff of wheat, rye, and oats, is richer in silica than any other part of these plants, and Bottinger found the seeds of the pine richer in silica than the wood. In numerous instances, silica is so deposited in or upon 184 I THE ASH OF PL LNTS. the cell-wall, that when the organic matters are destroyed by burning, or removed by solvents, the form of the cell is preserved in a silicious skeleton. This has long been known in case of the Equisetums and Deutzias. Here, the roughnesses of the stems or leaves which make these plants useful for scouring, are fully incrusted or interpenetrated by silica, and the' ashes of the cuticle present the same appearance under the microscope as the cuticle itself. Lately, Kindt, Wicke, and Mohl, have observed that the hairs of nettles, hemp, hops, and other rough-leaved plants, are highly silicious. The bark of the beech is coated with silica-hence the smooth and undecayed surface which its trunk presents. The best textile materials, which are bast-fibers of various plants, viz., common hemp, manilla-hemp, (M2usa textilis,) aloe-hemp, (Agave Americana,) common flax, and New Zealand flax, (Phormium tenax,) are completely incrusted with silica. In jute, (Corchorus textilis,) some cells are partially incrusted. The cotton fiber is free from silica. Wicke, (loc. cit.,) suggests that the durability of textile fibers is to a degree dependent on their content of silica. The great variableness observed in the same plant, and in the same part of the plant, as to the content of silica, would indicate that this substance is at least in some degree accidental. In the ashes of ten kinds of tobacco leaves, Fresenius & Will found silica to range from 5.1 to 18.4 per cent. The analysis of the ash of 13 samples of pea-straw, grown on different soils from the same seed during the same year, under direction of the "Landes Oeconomie Collegium," of Prussia, gave the following percentages of silica, viz.: 0.56; 0.75; 2.30; 2.32; 2.80; 3.29; 3.57; 5.15; 5.82; 8.03; 8.32; 9.77; 21.35. Analyses of the ash of 9 samples of colza-straw, all produced firom the same seed on different soils, gave the following percentages: 1.00; 1.14; 3.02; 3.57; 4.65; 5.08; 7.81; 11.88; 17.12. (Journal farprakt. 185 HOW CROPS GROW. Chem., xlviii, 474-7.) Such instances might be greatly multiplied. The idea that a part of the silica is accidental is further sustained by the fact observed by Saussure, the earliest investigator of the composition of the ash of plants, (]Recherches sur la FVegetation, p. 282,) that crops raised on a silicious soil are in general richer in silica than those grown on a calcareous soil. Norton found in the ash of the chaff of the Hopeton oat from a light loam 56.7 per cent, from a poor peat soil 50.0 of silica, while the chaff of the potatooat from a sandy soil gave 70.9 per cent. Salm-Horstmar obtained some remarkable results in the course of his synthetical experiments on the mineral food of plants, which fully confirmed him in the opinion that silica is indispensable to vegetation. He found that an oat plant, having for its soil pure quartz, (insoluble silica,) with addition of the elements of growth, soluble silica excepted, not only grew well, but contained in its ash 23010 of silica, or as great a proportion as exists in the plant raised under normal conditions. This silica may, however, have been mostly derived from the husk of the seed, for the plant was a very small one. Sachs, in 1862, was the first to publish evidence indicating strongly that silica is not a necessary ingredient of maize. He obtained in his early essays in water-culture a maize plant of considerable development, whose ashes contained but 0.70 10 of silica. Shortly afterwards, Knop produced a maize plant with 140 ripe seeds, and a dry-weight of 50 grammes, (nearly 2 oz. av.,) in a medium so free from silica that a mere trace of this substance could be found in, the root, but half a milligramme in the stem, and 22 milligrammes in the 15 leaves and sheaths. It was altogether absent from the seeds. The ash of the leaves of this plant thus contained but 0.54 per cent of silica, and the stem but 0.07 per cent. Way & Ogston found in the ash of maize, leaf and stem together, 27.98 per cent of silica 186 I i THE ASH OF PLANTS. Knop inclined to believe that the little silica he found in his maize plant was due to dust, and did not b)elong to the tissues of the plant. He remarked, "I believe that silica is not to be classed among the nutritive elements of the Graminee, since I have made similar observations in the analysis of the ashes of barley." In the numerous experiments that have been made more recently upon the growth of plants in aqueous solutions, by Sachs, Knop, Nobbe & Siegert, Stohmann, Rauten berg & Ktihn, Birner & Lucanus, Leydhecker, Wolff, and Hampe, silica, in nearly all cases, has been excluded, so far as it is possible to do so in the use of glass vessels. This has been done without prejudice to the development of the plants. Nobbe & Siegert and Wolff especially have succeeded in producing buckwheat, maize, and the oat, in full perfection of size and parts, with this exclusion of silica. Wolff, (FVs. St., VIII, p. 200,) obtained in the ash of maize thus cultivated, 2-30 10 of silica, while the same two varieties from the field contained in their ash 11-13~1o. The proportion of ash was essentially the same in both cases, viz., about 60 Io. Wolff's results with the oat plant were entirely similar. Birner & Lucanus, (Vs. St., VIII, 141,) found that the supply of soluble silicates to the oat made its ash very rich in silica, (40 10,) but diminished the growth of straw, without affecting that of the seed, as compared with plants nearly destitute of silica. While it is not thus demonstrated that utter absence of silica is no hindrance to the growth of plants which are ordinarily rich in this substance, it is certain that very little will suffice their needs, and highly probable that it is in no way essential to their physiological development. The Ash-Ingredients, which are indispensable to Crops, may be taken up in larger quantity than is essential.More than sixty years ago, Saussure described a simple 187 HOW CROPS GROW. experiment which is conclusive on this point. He gathered a number of peppermint plants, and in some determined the amount of dry-matter, which was 40.3 per cent. The roots of others were then immersed in pure water, and tne plants were allowed to vegetate 2~ months in a place exposed to sir and light, but sheltered from rain. At the termination of the experiment, the plants, which originally weighed 100, had increased to 216 parts, and the dry matter of these plants, which at first was 40.3, had become 62 parts. The plants could have acquired from the glass vessels and pure water no considerable quantity of mineral matters. It is plain, then, that the ash-ingredients which were contained in two parts of the peppermint were sufficient for the production and existence of three parts. We may assume, therefore, that at, least one-third of the ash of the original plants was in excess, and accidental. The fact of excessive absorption of essential ash-ingredients is also demonstrated by the precise experiments of Wolff on buckwheat, already described, (see p. 164,) where the'point in question is incidentally alluded to, and the difficulties of deciding how much excess may occur, are brought to notice. (See also pp. 176 and 179 in regard to potash and oxide of iron.) As a further striking instance of the influence of the nourishing medium on the quantity of ash-ingredients in the plant, the following is adduced, which may serve to put in still stronger light the fact that a plant does not always require what it contains. Nobbe & Siegert have made a comparative study of the composition of buckwheat, grown on the one hand in garden soil, and on the other in an aqueous solution of saline matters. (The solution contained sulphate of magnesia, chloride of calcium, phosphate and nitrate of potash, with phosphate of iron, which together constituted 0.316~ 1 of the liquid.) The ash-percentage was much higher in 188 THE ASH OF PLANTS. tha water-plants than in the garden-plants, as shown by the subjoined figures. ( Vs. St., V, p. 132.) PeR eenlt of ash in Stems and Leaves. Roots. Seeds. Entire Plant. Water-p]ant.....18.6 15.3 2.6 16.7 Garden-plant.... 8.7 6.8 2.4 7.1 We have seen that well-developed plants contain a larger proportion of ash than feeble ones, when they grow side by side in the same medium. In disregard of this general rule, the water-plant in the present instance has an ash-percentage double that of the land-plant, although the former was a dwarf compared with the latter, yielding but'I, as much dry matter. The seeds, however, are scarcely different in composition. Disposition by the Plant of excessive or superfluous ash-ingredients.-The ash-ingredients taken up by a plant in excess beyond its actual wants may be disposed of in three ways. The soluble matters-those soluble by themselves, and also incapable of forming insoluble combinations with other ingredients of the plant-viz., the alkali chlorides, sulphates, carbonates, and phosphates, the chlorides of calcium and magnesium, may 1, Remain dissolved in, and diffused throughout, the juices of the plant; or, 2,, May exude upon the surface as an efflorescence, and be washed off by rains. Exudation to the surface has been repeatedly observed in case of cucumbers and other kitchen vegetables, growing in the garden, as well as with buckwheat and barley in water-culture. ( Vs. St., VI, p. 37.) Saussure found in the white incrustations upon cucumber leaves, besides an organic body insoluble in water and alcohol, chloride of calcium, with a trace of chloride of magnesium. The organic substance so enveloped the chloride of calcium as to prevent deliquescence of. the latter. (Recherches sur la FVeg., p. 265.) 189 HOW CROPS GROW. Saussure proved that foliage readily yields up saline matters to water. Hie placed hazel leaves eight successive times in renewed portions of pure water, leaving them therein 15 minutes each time, and found that by this treatment they lost 1115 of their ash-ingredients. The portion thus dissolved was chiefly alkaline salts; but con. sisted in part of earthy phosphates, silica, and oxide of iron. (Recherches, p. 287.) Ritthausen has shown that clover which lies exposed to rain aftelr being cut, may lose by washing more than 112 of its ash-ingredients. Mulder, (Chemie der Ackerkrume, II, p. 305,) attributes to loss by rain a considerable share of the variations in percentage and composition of the fixed ingredients of plants. We must not, however, forget that all the experiments which indicate great loss in this way, have been made on the cut plant, and their results may not hold good to the same exteht for uninjured vegetation, which certainly does not admit of soaking in water. Further investigations must decide this point. 3. The insoluble matters, or those which become insoluble ill the plant, viz., the sulphate of lime, the oxalates, phosphates, and carbonates of lime and magnesia, the oxides of iron and manganese, and silica, may be deposited as crystals or concretions in the cells, or may incrust the cellwalls, and thus be set aside from the sphere of vital action. In the denser and comparatively juiceless tissues, as in bark, old wood, and ripe seeds, we find little variation in the content of soluble matters. These are present in large and variable quantity only in the succulent organs. In bark, (cuticle,) wood and seed envelopes, (husks, shells, chaff,) we often find silica, the oxides of iron and manganese, and carbonate of lime-all insoluble substances -accumulated in considerable amount. In bran-the cuticle of the kernels of cereals —phosphate of magnesia 190 I THE ASH OF PLANTS. exists in comparatively large quantity. In the dense teak wood, concretions of phosphate of lime have been noticed. Of a certain species of cactus, (Cactctts senilis,) 800 0 of the dry matter consists of crystals, probably a lime salt. That the quantity of matters thus segregated is in some degree proportionate to the excess of them in the nourishing medium in which the plant grows has been observed by Nobbe & Siegert, who remark that the two por. tions of buckwheat, cultivated by them in solutions and in garden soil respectively, (p. 188,) both contained crystals and globular crystalline masses, consisting probably of oxalates and phosphates of lime and magnesia, deposited in the rind and pith; buet that these were by far most abundzant in the water-plants, whose ash-percentage was twice as great as that of the land-plants. These insoluble substances may either be entirely unessential, as appears to be the case with silica, or, having once served the wants of the plant, may be rejected as no longer useful, and by assuming the insoluble form, are removed from the sphere of vital action, and become as good as dead matter. They are, in fact, excreted, though not, in general, formally expelled be- yond the limits of the plant. They are, to some extent, thrown off into the bark, or into the older wood, or pith, or else are virtually encysted in the living cells. y The occurrence of crystallized salts thus segregated in the cells of plants is illustrated by the following cuts. Fig. 23 represents Fig. 23. a crystallized concretion of oxalate Fig. 23. of lime, having a basis or skeleton of cellulose, from a leaf of the walnut. (Payen, Chimie tldustrielle P1. XII.) Fig. 24 is a mass of crystals of a lime salt, from the leaf stem of rhubarb. Fig. 25, similar crystals from the beet root. 191 HOW CROPS GROW. In the root of the young bean, Sachs found a ring of cells, containing crystals of sulphate of lime. (Sitzungsberichte der Wien. Akad., 37, p. 106.) Bailey observed in certain 1/)~>tA Ho parts of the inner bark of the locust a series of cells, each of which contained a crystal. In the onion-bulb, and many Fig. 24. Fig. 25. other plants, crystals are abundant. (Gray's Struct. Botany, 5th Ed., p. 59.) Instances are not wanting in which there is an obvious excretion of mineral matters, or at least a throwing of them off to the surface. Silica, as we have seen, is often found in the cuticle, but it is usually imbedded in the cellwall. In certain plants, other substances accumulate in considerable quantity without the cuticle. A striking example is furnished by Saxifraga crustata, a low European plant, which is found in lime soils. The leaves of this saxifiage are entirely coated with a scaly in- crustation of carbonate of lime i and carbonate of magnesia. At 5~0 the edges of the leaf, this incrusta- tion acquires a considerable thickness, as is illustrated by figure 26, a. In an analysis made by Unger, to whom these facts are due, the fresh, (undried,) leaves yielded to a dilute acid 4.1410 of carbonate of lime, and 0.82~0l of carbonate of magnesia. c: Unger learned by microscopic Fig. 26. investigation that this excretion of carbonates proceeds mostly from a series of glandular expansions at the margin of the leaf, which are directly connected with the sap-ducts of the plant. (Sitz'berichte der TWien. Akad., 43, p. 519.) 192 THE ASH OF PLAINTS. Iii figure 26, a represents the appearance of a leaf, magnified 4y diam. etels. Around the borders are seen the scales of carbonate of lime; some of these have been detached, leaving round pits on the surface of the leaf: c, d, exhibit the scales themselves, e in profile: b shows a leaf, freed from its incrustation by an acid, and fi-om its cuticle by potash solution, so as to exhibit the veins, (ducts,) and glands, whose course the carbonate of lime chiefly takes in its passage through the plant. Further as to the state of ash-ingredients.-It is by no means true that the ash-ingredients always exist in pl:'iits in the forms under which they are otherwise familiai to us. Arendt and Hellriegel have studied the proportions of soluble and insoluble matters, the former in the ripe oat plant, and the latter in clover at various stages of growth. Arendt extracted fiom the leaves and stems of the oat plant, after thorough grinding, the whole of the soluble matters by repeated washings with water.* He found that all the sulphuric acid and all the chlorine were soluble. Nearly all the phosphoric acid was removed by water. The larger share of the lime, magnesia, soda, and potash, was soluble, though a portion of each escaped solution. Oxide of iron was found in both the soluble and insoluble state. In the leaves, iron was found among the insoluble matters after all phosphoric acid had been removed. Finally, silica was mostly insoluble, though in all cases a small quantity occurred in the soluble condition, viz., 3-8 parts ill 10,000 of the dry plant. (Waechsthtim der Elftiepjlanze, pp. 168, 1834. See, also, table on p. 198.) Weiss and Wiesner have found by minicrochemical investi gation that iron exists as insoluble compounds of protox ide and sesquioxide, both in the cell-membrane and in the cell-contents. (Sitz'berichte der Wiener Akad., 40, 278.) Hellriegel found that a larger proportion of the various bases was soluble in young clover than in the mature plant. As a rule, the leaves gave most soluble matters, * To extract the soluble parts of the grain in this way was impossible. 9 193 HOW CROPS GROW. the leaf-stalks less, and the stems least. He obtained, among others, the following results. ( FVs. St., IV, p. 59.) Of 100 parts of the following fixed ingredients of clover, were dissolved in the sap, and not dissolved In young leaves. I?z full-gqrotn leam& dissolved........ 75.2 37.3 undissolved.......24.8 62.7 dissolved........ 69.5 72.4 undissolved....... 30.5 27.6 dissolved........ 43.6 78.3 undissolved.....56.4 21.7 dissolved........ 20.9 19.9 undissolved.....79.1 80.1 dissolved........ 26.8 16.1 undissolved....... 73.2 83.9 Potasi Lime Magnesia Phosphoric acid Silica These researches demonstrate that potash and sodabodies, all of whose commonly occunriing compounds, silicates excepted, are readily soluble in water-enter into insoluble combinations in the plant; while phosphoric acid, which forms insoluble salts with lime, magnesia, and iron, is freely soluble in connexion with these bases in the sap. It should be added that sulphates may be absent from the plant or some parts of it, although they are found in the ashes. Thus Arendt discovered no sulphates in the lower joints of the stem of oats after blossom, though in the upper leaves, at the same period, sulphuric acid, (S 03,) formed nearly 7~[0 of the sum of the fixed ingredients. (Wachsthum der Haferpf, p. 157.) Ulbricht found that sulphates were totally absent from the lower leaves and stems of red clover, at a time when they were present in the upper leaves and blossom. (V. St., IV, p. 30, Tabelle.) Both Arendt and Ulbricht observed that sulphur existed in all parts of the plants they experimented upon; in the parts just specified, it was, however, no longer combined to oxygen, but had, doubtless, become an integral part of some albuminoid or other complex organic body. Thus the oat stem, at the period above cited, contained a quantity of sulphur, which, had it been converted into sulphuric acid, would have amounted to 14~ lo of the fixed 194 i THE ASH OF PLANTS. ingredients. In the clover leaf, at a time when it was totally destitute of sulphates, there existed an amount of sulphur, which, in the form of sulphuric acid, would have made 13.7~1o of the fixed ingredients, or one per cent of the dry leaf itself.* Other ash-ingredients.-Salm-Horstmar has described some experiments, from which he infers that a minute amount of Lithia and Fluorine, (the latter as fluoride of potassium,) are indispensable to the fruiting of barley. (Joter. fur prakt. Chem., 84, p. 140.) The same observer, some years ago, was led to conclude that a trace of Titanic acid is a necessary ingredient of plants. The later results of water-culture would appear to demonstrate that these conclusions are erroneous. It is, however, possible, as Mulder has suggested, (Chemic der Ackerkrume, II, 341,) that the failure of certain crops, after long-continued cultivation in the same soil, may be due to the exhaustion of some of these less abundant and usually overlooked substances. Land not unfrequently becomes "clover-sick," i. e., refuses to produce good crops of clover, even with the most copious manurings. In Vaucluse, according to Mulder, the madder crop has suffered a deterioration in quality-the coloring effect of -e root having diminished one-fourth-as an apparent result of long cultivation on the same soil, although the seed is annually renewed from Asia Minor, and great care is bestowed on its culture. The newly discovered element, Rubidium, ]las been found in the sugar-beet, in tobacco, coffee, tea, and the * Arendt was the first to estimate sulphuric acid in vegetable matters with accuracy, and to discriminate it from the sulphur in organic compounds. This chemist determined the sulphuric acid of the oat-plant by extracting the pulverized material with acidulated water. He likewise estimated the total sulphur by a special method, and by subtracting the sulphur of the sulphuric acid from the total, he obtained as a difference that portion of sulphur which belonged to the albuminoids, etc. In his analyses of clover, /bcht followed a similar plan. (Vg. St., ]I, p. 147.) As has already been stated, many of the older analyses are wholly untrustworthy as regards sulphur and sulphuric acid. 195 HOW CROPS GROW. grape. It doubtless occurs perhaps, together with Cae8sium, in many other plants, though in very minute quantity. It is not unlikely that small quantities of these alkali-metals may be found to be of decided influence on the growth of plants.* The late investigations of A. Braun and of Risse, (Sachs, Exp. Physiologie, 153,) show that Zinc is a usual ingredient of plants growing about zinc mines, where the soil contains carbonate or silicate of this metal. Certain marked varieties of plants are peculiar to, and appear to have been produced by, such soils, viz., a violet, ( Viola tricolor, var. calaminaris,)t and a shepherd's purse, (Thlaspi alpestre, var. calaminaris.) In the ash of the leaves of the latter plant, Risse found 13~1o of oxide of zinc; in other plants he found from 0.3 to 3.3~ L. Copper is often or commonly found in the ashes of plants; and other elements, viz., Arsenic, Baryta,and Lead, have been discovered therein, but as yet we are not fairly warranted in assuming that any of these substances are of importance to agricultural vegetation. The same is true of Iodine, which, though an invariable and probably a necessary constituent of many algae, is not known to exist to any considerable extent or to be essential in any culti vated plants. ~ 4. FUNCTIONS OF THE ASH-INGREDIENTS. But little is certainly known with reference to the subject of this section. Sulphates.-The albuminoids, which contain sulphur as an essential ingredient, obviously cannot be produced in absence of sulphuric acid, which, so far as we know, is the * Since the above was written, Birner & Lucanus I ave found that these bodies, it the absence of potash, act as poisons to the oat. (Vs. St., VIII, p. 147.) t By some botanists ranked as a distinct species. 196 THE ASI1 OF PLANTS. single source of sulphur to plants. The sulphurized oils of the onion, mustard, horseradish, turnip, etc., likewise require sulphates for their organization. Phosphates.-The phosphorized oils (protagon) require to their elaboration that phosphates or some source of phosphorus be at the disposal of the plant. The physiological function of the phosphates, so abundant in the cereals, admits of partial explanation. The soluble albuminoids which are formed in the foliage must pass thence through the cells and ducts of the stem into growing parts of the plant, and into the seed, where they accumulate in large quantity. But the albuminoids penetrate membranes with great difficulty and slowness when in the pure state. According to Schumacher, (Physik der Pganze, p. 128,) the phosphate of potash considerably increases the diffusive rate of albumin, and thus facilitates its translocation in the plant. Alkalies and alkali-earths.-The organic acids, viz.: oxalic, malic, tartaric, citric, etc., require alkalies and alkali-earths to form the salts which exist in plants, e.g. bitartrate of potash in the grape, oxalate of lime in beetleaves, malate of lime in tobacco; and without these bases it is, perhaps, in most cases impossible for the acids to be formed, though in the orange and lemon, citric acid exists in the uncombined or free state, and in various plants, as Sempervivu?2 arboreum, and Cacalia ficoides, acids are formed during the night which disappear in the day. The leaves of these plants are sour in the morning, tasteless at noon, and bitter at night. (iHeyne & Link).) Silica.-The function of silica might appear to be, in case of the grasses, sedges, and equLisetums, to give rigidity to the slender stems of these plants, and enable them to sustain the often heavy weight of the fruit. Two circumstances, however, embarrass the unqualified acceptance of this notion. The first is, that the proportion of silica is not great .197 IHOW CROPS GROW. est in those parts of the plant which, on this view, would most require its presence. Thus Norton, (Am. Tour. of Sci., [2,] vol. iii, pp. 235-6,) found that in the sandy oat the upper half of the dry leaf yielded 16.2 per cent ash, while the lower half gave but 13.6 per cent. The ash of the upper part contained 52.1 per cent of silica, while that from the bottom part had but 47.8 per cent of this ingredient. According to Arendt, (1)as Wtachsthum der tHaferpflanze, p. 180,) the different parts of the oat contain the following quantities of silica respectively: Amount of silica it 1000 parts of dry substance. R2moved Insoluble by water. in water. Total. Lower part of the stem.....0.33 1.4 1.7 Middle part of the stem....0.30 4.8 5.1 Upper part of the stem.....0.36 13.0 13.3 Lower leaves...............0.86 34.3 35.2 Upper leaves...............0.52 43.3 43.8 We see then, plainly, that the upper part of the stem and leaves contains more silica than the lower parts, while the lower parts certainly need to possess the greatest degree of strength. We must not forget, however, as Knop has remarked, that the lower part of the leaf of most cereals and grasses which envelopes the stem like a sheath, is really the support of the plant as much as, or even more, than the stem itself. The results of the many experiments in water-culture by Saclhs, Knop, Wolff, and others, (see p. 186,) in which the supply of silica has been reduced to an extremely small amount, without detriment to the development of plants, commonly rich in this substance, would seem to demonstrate that silica does not essentially contribute to the stiffness of the stem. Wolff distinctly informs us that the maize and oat plants produced by him, in solutions nearly free from silica, were as firm in stalk, and as little inclined to lodge or "lay, i as those which grew in the field. 198 THE ASH OF PLANTS. The recommendation to supply silex to grain crops, in order to stiffen the straw and prevent falling of the crop oefore it ripens, either by directly applying alkali-silicates, or by the use of fertilizers and amendments that may render the silica of the soil soluble, must, accordingly, be considered entirely futile from the point of view of the needs of the crop, as it is from that of the resources of the soil. Chlorine.-As has been mentioned, both Nobbe and Leydhecker found that buckwheat grew quite well up to the time of blossom without chlorine. From that period on, in absence of chlorine, remarkable anomalies appeared in the development of the plant. In the ordinary course of growth, starch, which is organized in the mature leaves, does not remain in them to much extent, but is transferred to the newer organs, and especially to the fruit, where it also accumulates in large quantities. In absence of chlorine, in the experiments of Nobbe and Leydhecker, the terminal leaves became thick and fleshy, from extraordinary development of cell-tissue, at the same time they curled together and finally fell off, upon slight disturbance. The stem became knotty, transpiration of water was suppressed, the blossoms withered without fructification, and the plant prematurely died. The fleshy leaves were full of starch-grains, and it appeared that in absence of chlorine the transfer of starch from the foliage( to the flower and fruit was rendered impossible; in other words, chlorine (in combination with potassium or calcium) was concluded to be necessary to, was, in fact, the agent of this transfer. Knop believes, however, that these phenomena are due to some other cause, and that chlorine is not essential to the perfection of the fruit of buckwheat, (see p. 182). Iron.-We are in possession of some interesting facts, which appear to throw light upon the function of this metal in the plant. In case of the deficiency of this ele ment, foliage loses its natural green color, and becomes pale or white even in the full sunshine. In absence of iron a 199 HOW CROPS GROW. plant may unfold its buds at the expense of already organ. ized matters, as a potato-sprout lengthens in a dark cellar, or in the manner of fungi and white vegetable parasites; but the leaves thus developed are incapable of assimilating carbon, and actual growth or increase of total weight is impossible. Salm-Horstmar showed that plants which grow in soils or media destitute of iron, are very pale in color, and that addition of iron-salts very speedily gives them a healthy green. Sachs found that maize-seedlings, vegetating in solutions free from iron, had their first three or four leaves green; several following were white at the base, the tips being green, and afterward, perfectly white leaves unfolded. On adding a few drops of sulphate or chloride of iron to the nourishing medium, the foliage was plainly altered within 24 hours, and in 3 to 4 days the plant acquirel a deep, lively green. Being, afterwards transferred to a solution destitute of iron, perfectly white leaves were again developed, and these were brought to a normal color by addition of iron. E. Gris was the first to trace the reason of these effects, and first found, (in 1813,) that watering the roots of plants with solutions of iron, or applying such solutions externally to the leaves, shortly developed a green color where it was previously wanting. By microscopic studies he found that in the absence of iron, the protoplasm of the leaf-cells remains a colorless or yellow mass, destitute of visible organization. Under the influence of iron, grains of chlorophyll begin at once to appear, and pass through the various stages of normal development. We know that the power of the leaf to decompose carbonic acid and assimilate carbon, resides in the cells that contain chlorophyll, or, we may say, in the chlorophyll-grains themselves. We understand at once, then, that in the absence of iron, which is essential to the formation of chlorophyll, there can be no proper growth, no increase at the expense of the external atmospheric food of vegetation. 200 QUANTITATIVE RELATIONS. Risse, under Sachs' direction, (.xp. Physiologie, 143,) demonstrated that manganese cannot take the place of iron in the office just described. Functions of other Ash-Ingredients.-As to the special uses of the other fixed matters we know little. It appears to be proved beyond doubt that potash, lime, and magnesia, are indispensable to the life and health of animals, and since all animals derive the chief part of their sustenance from the vegetable world, it is obvious that these substances must be ingredients of plants in order to fit the latter for their nutritive office; but why no vegetable cell can be elaborated without potash, why lime and magnesia are imperative necessities to plants, we are as yet not able to comprehend. CHAPTER ]IL ~ 1. QUANTITATIVE RELATIONS AMONG THE INGREDIENTS OF PLANTS. Various attempts have been made to exhibit definite numerical relations between certain different ingredients of plants. Equivalent Replacement of Bases.-In 1840, Liebig, in his Chemistry applied to Agriculture, suggested that the various bases might displace each other in equivalent quantities, i. e., in the ratio of their molecular weights, and that were such the case, the discrepancies to be observed among analyses should disappear, if the latter were interpreted on this view. Liebig instanced two analyses of the ashes of fir-wood and two of pine-wood made by Berthier and Saussure, as illustrations of the correctness of this theory In the fir of Mont Breven, carbonate of 9* HOOW CROPS GROW. magnesia was present; in that of Mont La Salle, it was absent. In the former existed but half as much carbonate of potash as in the latter. In both, however, the same total percentage of alkali and earthy carbonates was found, and the amount of oxygen in these bases was the same in both instances. Since the unlike but equivalent quantities of potash, lime, and magnesia, contain the same quantity of oxygen, these bases, in the case in question, do displace each other in equivalent proportions. The same was true for the ash of pine-wood, from Allevard and from Norway. On applying this principle to other cases it has, however, signally failed. The fact that the plant can contain accidental or unessential ingredients, renders it obvious that, however truly such a law as that of Liebig may in any case apply to those substances which are really concerned in the vital actions, it will be impossible to read the law in the results of analyses. Relation of Phosphates to Albuminoids.-Liebig likewise considers that a definite relation must and does exist between the phosphoric acid and the albuminoids of the ripe grains. That this relation is not constant, is evident from the following statement of the data, that have been as yet obtained, bearing on the question. In the table, the amount of nitrogen (N), representing the albuminoids (see p. 108) found in various analyses of rye and wheat grain, is compared with that of phosphoric acid (PO05), the latter being taken as unity. POs N. In 7 Samples of Rye-kernel Fehling & Faiszt found the ratio of PO 5 to N to range from......1: 1.97-.06 do 11 do do do Mayer do do do 1: 2.04-2.38 do.5 do do do Bibra do do do 1: 1.68-2.81 do 6 do do do Siegert do do do 1: 2.35-2.96 do 28 do do do the extreme range was from...........1 1.68 —3.06 do 2 do of Wheat-kernel Fehling & Faiszt found the ratio of PO5 to N to range from.......1: 2.71-2.86 do 11 do do do Mayer do do do 1 1.83-2.19 do 2 do do do Zoeller do do do 1: 2.02-2,16 do 30 do do do Bibra do do do I: 1.87-3.55 do 6 do do do Siegert do do do 1: 2.30-3.33 do 51 do do do the extreme range was from...........1 1:833.5 202 COMPOSION IN SUCCESSIVE STAGES. Siegert, who has collected these data, (FV. St., III, 147,) and who experimented on the influence of phosphatic and nitrogenous fertilizers upon the composition of wheat and rye, gives as the general result of his special inquiries, that Phosphoric acid and Nttrogen stand in no constant relation to each other. Nitrogenous manures increase the per cent of nitrogen and diminish that of phosphoric acid. Other Relatlons.-All attempts to trace simple and constant relations between other ingredients of plants, viz.: between starch and alkalies, cellulose and silica, etc., etc., have proved fruitless. It is much rather demonstrated that the proportions of the constituents is constantly changing from day to day as the relative mass of the individual organs themselves undergoes perpetual variation. In adopting the above conclusions, it is not asserted that such genetic relations between phosphates and al buminoids, or between starch and alkalies, as Liebig first suggested and as various observers have labored to show, do not exist, but simply that they do not appear from the analyses of plants. ~ 2. THE COMPOSITION OF THE PLANT IN SUCCESSIVE STAGES OF GROWTH. We have hitherto regarded the composition of the plant mostly in a relative sense, and have instituted no comparisons between the absolute quantities of its ingredients at different stages of growth. We have obtained a series of isolated views of the entire plant, or of its parts at some certain period of its life, or when placed under certain condlitions, and have thus sought to ascertain the peculiarities of these periods and to estimate the influence of these con. 203 BOW CROPS GROW. ditions. It now remains to attempt in some degree the combination of these sketches into a panoramic pictureto give an idea of the composition of the plant at the successive steps of its development. We shall thus gain some insight into the rate and manner of its growth, and acquire data that have an important bearing on the requisites for its perfect nutrition. For this purpose we need to study not only the relative (percentage) composition of the plant and of its parts at various stages of its existence, but we must also inform ourselves as to the total quantities of each ingredient at these periods. Wye shall select from the data at hand those which illustrate the composition of the oat-plant. Not only the ashingredients, but also the organic constituents, will be noticed so far our information and space permit. The Composition and Growth of the Oat-Plant mnay be studied as a type of an important class of agricultural plants, viz.: the annual cereals-plants which complete their existence in one summer, and which yield a large quantity of nutritious seeds-the most valuable result of culture. The oat-plant was first studied in its various parts and at different times of development by Prof John Pitkin Norton, of Yale College. His laborious research published in 1846, (Trans. ffiyAland and Ag. Soc. 1845-7, also Am. Tour. of Sci. and Arts, Vol. 3, 1847,) was the first step in advance of the single and disconnected analyses which had previously been the only data of the agricultural physiologist. For several reasons, however, the work of Norton was imperfect. The analytical methods employed by him, though the best in use at that day, and handled by him with great skill, were not adapted to furnish results trustworthy in all particulars. Fourteen years later, Arendt,* at Moeckern, and Bretschneider,t at Saaran, * Wachsthumsverh itnisse der Taferpflane, Jour. fur Prakat. Chem., 76,193. + Das Wachsthum der Haferpflanze, Leipzig. 1859. 204 COMPOSMITION IN SUCCESSIVE STAGES. in Germany, at the same time, but independently of each other, resumed the subject, and to their labors the subjoined figures and conclusions are due. Here follows a statement of the Periods at which the plants were taken for analysis. 1st Period1 June 18, Arendt-Three lower leaves unfolded, two upper still closed. t Period "19, Bretschneider-Four to five leaves developed. 2d Period t June 30, (12 days,) At.-Shortly before the plants were fully headed. ) " 29, (10 days,) Br.-The plants were headed. 8d Period) July 10, (10 days,) At.-Immediately after bloom. f " 8, (9 days,) Br.-Full bloom. 4th Period } July 21, (11 days,) At.-Beginning to ripen. ' 28, (20 days,) BP.- " " 5th Period tJuly 31, (10 days,) At.-Fully ripe. Aug. 6, (9 days,) Br.- " " It will be seen that the periods, though differing somewhat as to time, correspond almost perfectly in regard to the development of the plants. It must be mentioned that Arendt carefully selected luxuriant plants of equal size, so as to analyze a uniform material, (see p. 210,) and took no account of the yield of a given surface of soil. Bretschneider, on the other hand, examined the entire produce of a square rod. The former procedure is best adapted to study the composition of the well-nourished individualpant; the latter gives a truer view of the crop. The unlike character of the material as just indicated is but one of the various causes which might render the two series of observations discrepant. Thus, differences in soil, weather, and seeding, would necessarily influence the relative as well as the absolute development of the two crops. The results are, notwithstanding, strikingly accordant in many particulars. In all cases the roots were not and could not be included in the investigation, as it is impossible to free them from adhering soil. The Total Weight of Crop per English acre, at the end of each period, was as follows: 205 HOW CROPS GROW. TABLE I.-Br. 1st Period, 6,358 lbs. avoirdup;is. 2d " 10,603 " 3d " 16,523 " 4th " 14,981 5th " 10,622 " " The Total Weights of Water and Dry Matter for all but the 2d Period-the material of which was accidentally lost-were: TABLE II.-Br. Dry Matter, Water, lbs. av. per acre. lbs. av. per acre. 1st Period, 1,284 5,074 3d " 4,383 12,240 4th " 5,427 14,983 5th " 6,886 3,736 1.-From Tab. I it is seen: That the weight of the live crop is greatest at or before the time of blossom.* After this period the total weight diminishes as it had previously increased. 2.-From Tab. II it becomes manifest: That the organic tissue (dry matter) continually increases in quantity up to the maturity of the plant; and 3.-The loss after the 3d Period falls exclusively upon the water of vegetation. At the time of blossom the plant has its greatest absolute quantity of water, while its least absolute quantity of this ingredient is found when it is fully ripe. By taking the difference between the weights of any two Periods, we obtain: The Increase or Loss of Dry Matter and Water during each Period. TABLE III.-Br. Dry.Matter, Water, lbs. per acre. lbs. per acre. 1st Period, 1,284 Gain. 5,073 Gain. 3d " 3,099 " 7,166 " 4th " 1,044 " 2,684 Loss. 5th " 1,459 " 5,820 " * In Arendt's Experiment, at the time of "heading out," 8d Period. 206 COMPOSITON IN SUCCESSIVE STAGES. On dividing the above quantities by the number of days of the respective periods, there results: The Average Daily Gain or Loss per Acre during each Period. TABLE IV.-Br. Dry Matter. Water. 1st Period, 22 lbs. Gain. 87 lbs. Gain. 3d " 163 " " 382 " " 4th " 65" " 167 " Loss. 5th " 112 " " 447 " " 4.-Table III, and especially Tab. IV, show that the-gain of organic matter in Bretschneider's oat-crop went on most rapidly at or before the time of blossom, (according to Arendt at the time of heading out.) This was, then, the period of most active growth. Afterward the rate of growth diminished by more than one-half, and at a later period increased again, though not to the maximum. Absolute Quantities of Carbon, Hydrogen, Oxygen, Nitrogen, and Ash, in the dry oat crop at the conclusion of the several periods; (ibs. per acre.) TABLE V.-Br. Carbon. Hydrogen. Oxygen. Nitrogen. Ash.* 1st Period, 593 80 455 46 110 3d " 2,137 286 1,575 122 263 4th " 2,600 343 2,043 150 291 5th " 3,229 405 2,713 167 372 Relative Quantities of Carbon, Hydrogen, Oxygen, Nitrogen, (Organic Matter,) and Ash in the dry oat crop, at the end of the several Periods; (per cent.) TABLE VI.-Br. Carbon. Hydrogen. Oxygen. Yitrogen. (Organic Matter.) Ash. 1st Period, 46.22 6.23 35.39 3.59 91.43 8.57 3d " 48.76 6.53 35.96 2.79 94.04 5.96 4th " 47.91 6.33 37.65 2.78 94.67 5.33 5th " 46.89 5.88 39.40 2.43 94.60 5.40 * In Bretschneider's analyses, "ash" signifies the residue left after carefully burning the plant. In Arendt's investigation the sulphur and chlorine were do. termined in the unburned plant. 207 HOW CROPS GROW. Relative Quantities of Carbon, Hydrogen, Oxygen, and Nitrogen, in dry substance, after deducting the somewhat variable amount of ash, (per cent). TABLE VII.-Br. Hydrogen. 6.81 6.95 6.96 6.21 5.-The Tables V, VI, and VII, demonstrate that while the absolute quantities of the elements of the dry oat plant continually increase to the time of ripening, they do not increase in the same proportion. In other words, the plant requires, so to speak, a change of diet as it advances in growth. They further show that nitrogen and ash are relatively more abundant in the young than in the mature plant; in other words, the rate of assimilation of Nitrogen and fixed ingredients falls behind that of Carbon, Hydrogen, and Oxygen. Still otherwise expressed, the plant as it approaches maturity organizes relatively more amyloids and relatively less albuminoids. The relations just indicated appear more plainly when we compare the Quantities of Nitrogen, Hydrogen, and Oxygen, assimilated during each period, calculated upon the amount of Carbon assimilated in the same time and assumed at 100. TABLE VIII.-Br. Carbon. Nitrogett. Hydrogen. Oxyge. 1st Period, 100 7.8 13.4 73.6 3d " 100 i4.9 13.3 72.5 4th " 100 6.1 12.3 100.8 5th " 100 2.6 10.6 106.5 From Table VIII we see that the ratio of Hydrogen to Carbon regularly diminishes as the plant matures; that of Nitrogen falls greatly from the infancy of the plant to the period of full bloom, then strikingly increases during the 208 Carbon. 50.55 51.85 50.55 49.59 Oxijgen. 38.71 38.24 39.83 41.64 Nit7'Ogeft. 3.93 . 2.86 2.93 2.56 lst Period, 3d It 4th 11 5th 11 CO]MPOSITION IN SUCCESSIVE STAGES. first stages of ripening, but falls off at last to minimum. The ratio of Oxygen to Carbon is the same during the 1st and 3d periods, but increases remarkably from the period . of full blossom until the plant is ripe. As already stated, the largest absolute assimilation of all ingredients —most rapid growth-takes place at the time of heading out, or blossom. At this period all the volatile elements are assimilated at a nearly equal rate, and at a rate equal to that at which the fixed matters (ash) are absorbed. In the first period Nitrogen and Ash; in the fourth period Nitrogen and Oxygen; in the fifth period Oxygen and Ash are assimilated in largest proportion. This is made evident by calculating for each period the Daily Increase of Each Ingredient, the amount of the ingredients in the ripe plant being assumed at 100 as a point of comparison. The figures resulting from such a calculation are given in TABLE IX.-Br. Hydrogen. Oxyge n. 0.33 0.28 2.68 2.17 0.88 1.07 1.16 1.89 The increased assimilation of the 5th over the 4th period is, in all probability, only apparent. The results of analysis, as before mentioned, refer only to those parts of the plant that are above ground. The activity of the foliage in gathering food from the atmosphere is doubtless greatly diminished before the plant ripens, as evidenced by the leaves turning yellow and losing water of vegetation. The increase of weight in the plant above ground probably proceeds from matters previously stored in the roots, which now are transferred to the fruit and foliage, and maintain the growth of these parts after their power of assimilatirg inorganic food (COs, H1O, NH,, N20,) is lost. 209 Carbon. 0.31 2.51 0.89 1.49 Nitrogen. 0.47 2.39 1.06 0.75 Ash. 0.50 2.13 0.47 1.70 Ist Period, 3d 44 4th 11 5th 11 HOW CROPS GROEW. The following statement exhibits the Average Daily Increase of Carbon, Hydrogen, Oxygen, Nitrogen, and Ash, (in lbs. per acre) during the several periods. TABLE X.-Br. Hydrogen. 1.13 8.94 2.95 3.89 Turning now to Arendt's results, which are carried more !:lto detail than those of Bretschneider, we will notice A.-The Relative (percentage) Composition of the Entire Plant and of its Parts * during the several periods of vegetation. 1. Fiber t is found in greatest relative quantity40o loin the lower joints of the stem, and from the time when the grain " heads out," to the period of bloom. Relatively considered, there occur great variations in the same part of the plant at different stages of growth. Thus, in the ear, which contains the least fiber, the quantity of this substance regularly diminishes, not absolutely, but only relatively, as the plant becomes older, sinking from 27~ 10o, at heading, to 1201o, at maturity. In the leaves, which, as regards fiber, stand intermediate between the stem and ear, this substance ranges from 22~ I, to 38~0. Previous to blossom, the upper leaves, afterwards the lower leaves, are the richest in fiber. In the lower leaves the maximum, * Arendt selected large and well-developed plants, divided them into six parts, and analyzed each part separately. His divisions of the plants were 1, the threei lowest joints of the stem; 2, the two middle joints; 3, the upper joint; 4, the three lowest leaves; 5, the two upper leaves; 6, the ear. The stems were cut just above the nodes, the leaves included the'sheaths, the ears were stripped from the stem. Arendt rejected all plants which were not perfect when gathered. When neariy ripe, the cereals, as is well known, often lose one or more of their lower leaves. For the numerous analyses on which these conclusions are based we must refer to the original. t i.e., Che cemu/e; see p. 60, 210 Carbon. 8.43 66.95 23.84 39.85 Oxygen. 6.30 48.06 24.06 42.44 ,rttrogen. 0.65 3.30 1.47 1.04 Ash. 1.56 6.55 1.44 5.23 lr,t Period, 3d 11 4th 11 5th 11 COMPOSITION IN SUCCESSIVE STAGES. (33'1o,) is found in the 4th; in the upper leaves, (38~ 1o,) in the 2d period. The apparent diminution in amount of fiber is due in all cases to increased production of other ingredients. 2. -Fat and Wax are least abundant in the stem. Their proportion increases, in general, in the upper parts of the stem, as well as in the later stages of its growth. The range is from 0.2~ 10 to 3~ 10. In the ear the proportion increases firom 2~10 to 3.7~o. In the leaves the quantity is much larger and is mostly wax. The smallest proportion is 4.8~10, which is found in the upper leaves, when the plant is ripe. The largest proportion, (10~0o,) exists in the lower leaves, at the time of blossom. The relative quantities found in the leaves undergo considerable variation from one stage of growth to another. 3. Yion-nitrogenous matters, other than flber,-starch, stgar, etc.,*-undergo great and irregular variation. In the stem the largest percentage, (57~o ) is found in the young lower joints; the smallest, (43~1,,) in ripe upper straw. Only in the ear occurs a regular increase, viz., from 54 to 630 o. 4. The Albumino'id,t in Arendt's investigation, exhibit a somewhat different relation to the vegetable substance, from what was observed by Bretschneider, as seen from the subjoined comparison of the percentages found at the different periods. Periods. I. II. III. IV. V. Arendt.......... 20.93 11.65 10.86 13.67 14.30 Bretschneider.....22.73 17.67 17.61 15.39 These differences may be variously accounted for. They are due, in part, to the fact that Arendt analyzed only large and perfect plants. Bretschneider, on the other * What remains after deducting fat and wax, albuminoids, fiber, and ah, from the dry substance, is here included. t Calculated by multiplying the percentage of nitrogen by 6.33. 211 HOW CROPS GROW. hand, examined all the plants of a given plot, large and small, perfect and injured. The differences illustrate what has been already insisted on, viz., that the development of the plant is greatly modified by the circumstances of its growth, not only in reference to its external figure, but also as regards its chemical composition. The relative distribution of nitrogen in the parts of the plant at the end of the several periods is exhibited by the following table, simple inspection of which shows the fluctuations, (relative,) in the content of this element. The percentages are arranged for each period separately, proceeding fiom the highest to the lowest: PERIODS. I. II. III. IV. V. Upper leaves. Lower leaves. Upper leaves. Ears. Ears. 3.74 2.39 2.27 2.85 3.04 Lower leaves. Upper leaves. Lower leaves. Upper leaves. Upper leaves. 3.38 2.19 2.18 1.91 1.74 Lower leaves. Ears. Ears. Lower leaves. Upper stem. 2.15 2.06 1.85 1.62 1.56 Middle stem. Upper stem. Upper stem. Lower leaves. 1.5, 1.34 1.60 L43 Upper stem. Middle stem. Middle stem. Middle stem. 0.87 0.98 1.20 1.17 Lower stem. Lower stem. Lower stem. Lower stem. 0.80 0.88 0.83 0.79 5, Ash.-The agreement of the percentages of ash in the entire plant, in corresponding periods of the growth of the oat, in the independent examinations of Bretschneider and Arendt is remarkably close, as appears from the figures below. PERIODS.' I. II. III. IV. V. Bretschneider......8.57 5.96 5.33 5.40 ~Aren~dt.....8.03 5.24 5.44 5.20 5.1. The diminution at the 2d, increase at the 3d, and subsequent diminution at the 4th period, are observed to run parallel in both cases. As regards the several parts of the plant, it was found 212 COMPOSITION IN SUCCESSIRVE STAGES. by Arendt that of the stem the upper portion was richest in ash throughout the whole period of growth. Of the leaves, on the contrary, the lower contained most fixed matters. In the ear there occurred a continual decrease from its first appearance to its maturity, while in the stem and leaves there was, in general; a progressive increase to war( s the time of ripening. The greatest percentage, (10.50 Io) was found in the ripe leaves; the smallest, (0.780 lo,) in the ripe lower straw. Far more interesting and instructive than the relative proportions are B-The absolute quantities of the ingredients found in the plant at the conclusion of the several periods of growth.-These absolute quantities, as found by Arendt, in a given number of carefully selected and vigorous plants, do not accord with those obtained by Bretschneider from a given area of ground, nor could it be expected that they should, because it is next to impossible to cause the same amount of vegetation to develope on a number of distinct plots. Though the results of Bretschneider more nearly represent the crop as obtained in farming, those of Arendt give a truer idea of the plant when situated in the best possible conditions, and attaining a uniformly high development. We shall not attempt to compare the two sets of observations, since, strictly speaking, in most points they do not admit of comparison. From a knowledge of the absolute quantities of the substances contained in the plant at the ends of several periods, we may at once estimate the rate of growth, i.e., the rapidit3 with which the constituents of the plant are either taken up or organized. The accompanying table, which gives in alternate col. umns the total weights of 1,000 plants at the end of the several periods, and, (by subtracting the first from the 213 HOW CROPS GROW. second, the second from the third, etc.,) the gain from matters absorbed or produced during each period, will serve to justify the deductions that follow, which are taken from the treatise of Arendt, and which apply, of course, only to the plants examined by this investigator. 1,000 ENTIRE PLANTs, (WATER-FREE.) | a Am-. ~f | - o | | Z 0|8 ~nue.~ ~ Ol~'~l.q' j I o) 3 leaves Hedn Beinn in open.5 out. Blossomed. to r~~~~~ipe. Rie 95.4 158.9 63 34.2~~~~~~~~O 16 Fat.......[maters 20. 489 2Lo~ Organic matter..........419.2 1292.2 873 0 1~~~~~b 2 47~~ 1 22 128.6 Silica...................... Sulphuric acid........... Phosphoric acid.......... Oxide of iron............. Lime....................... Magnesia................. Chlorine.................. Soda....................... Potash..................... Ash........................ Dry Matter................ 1. The plant increases in total weight, (dry matter,) through all its growth, but to unequal degrees in different periods. The greatest growth occurs at the time of heading out; the slowest, within ten days of maturity. We may add that the increase of the oat after blossom takes place mostly in the seed, the other organs gaining but little. The lower leaves almost cease to grow after the 2d period. 2. Fiber is produced most largely at the time of heading out, (2d period.) When the plant has finished blossoming, (end of 3d period,) the formation of fiber entirely ceases. Afterward there appears to occur a slight diminu The weights in this table are grams. One gram- 15.434 grains. As the weights have mostly a comparative value, reduction to the English standard is unnecessary 7 9 6 2 1 1 8 9 7 8 2 I 0 1 7 214 -,t I .5 -, ";! .5,'-;a I- 5- 0.;a — . I.,t <..;. Q 0 93. z t,t u.. - 11= Iz -11 6.39 15.82 1.06 2.71 3.27 5.99 0.20 0.46 4.48 8.50 1.53 2.71 2.28 3.62 0.86 i.28 17.05 31.11 36.60 70.08 455.8 1363.6 9.43 1.65 2.72 0.26 4.02 1.18 1.34 0.42 14.06 33.48 907.8 25.45 2.68 10. 3 —) 0.61 11.60 3.71 5.32 1.47 40.20 100.41 1867.6 9.63 34.66 0 483 4.33 12.90 0.15 0.83 3. 10 14.49 1.01 5.42 1.70 5.96 0.19 1.12 9.09 44.33 30.33 120.75 r,04.0 2323.8 9.21 2.12 2.58 0.22 2.89 1.71 0.64 L088 4.13 20.34 456.2 36.32 5.34 14.23 0.58 14.71 6.45 5.78 0.87 43.76 126.93 2458.5 1.66 0.41 1.33 Los8 0.22 1.03 Los-9 Los8 Lo-9.9 7.18 134.7 COMPOSITION IN SUCCESSIVE STAGES. tion of this substance, probably due to unavoidable loss of lower leaves, but not to a resorption or metamorphosis in the plant. 3. Fat is formed most largely at the time of blossom. It ceases to be produced some weeks before ripening. 4, The formation of Albuminoid is irregular. The greatest amount is organized during the 4th period, (after blossoming.) The gain in albuminoids within this period is two-fifths of the total amount found in the ripe plant, and also is nearly two-fifths of the entire gain of organic substance in the same period. The absolute amount organized in the 1st period is not much less than in the 4th, but in the 2d, 3d, and 5th periods, the quantities are considerably smaller. Bretschneider gives the data for comparing the production of albuminoids in the oat crop examined by him with Arendt's results. Taking the quantity found at the conelusion of the 1st period as 100, the amounts gained during the subsequent periods are related as follows: PERIODS. 1. IL. III. (It & III.) IV. (II, III & IV.) V. Arendt........ 100 67 46 (113) 120 (233) 36 Bretschneider....100?? (165) 62 (227) 35 We perceive striking differences in the comparison. In Bretschneider's crop, the increase of albuminoids goes on most rapidly in the 3d period, and sinks rapidly during the time when in Axrendt's plants it attained the maximum. Curiously enough, the gain in the 2d, 3d, and 4th periods, taken together, is in both cases as good as identical, (233 and 227,) and the gain during the last period is also equal. This coincidence is doubtless, however, merely accidental. Comparisons with other crops of oats,examined,though very incompletely, by Stockhardt, (Chemischer Ackersmann, 1855,) and Wolff, (Die Erschopfung des Bodens durch die Cultur, 1856,) demonstrate that the rate of assimilation is not related to any special times or periods of developmeit, 215 I HOW CROPS GROW. but depends upon the stores offood accessible to the plant and the favorableness of the weather to growth. The following figures, which exhibit for each period of both crops a comparison of the gain in albuminoids with the increase of the other organic matters, further demonstrate that in the act of organization, the nitrogenous principles have no close quantitative relations to the non-nitrogenous bodies, (amyloids and fats.) The quantities of albuminoids gained during each period being represented by 10, the amounts of amyloids, etc., are seen from the subjoined ratios: PERIODS. Ratio in I. II & III. IV. V. Ripe PRant. Arendt........ 10: 34 10: 114 10: 28 10: 25 10: 66 Bretschneider..10: 30 10: 50 10: 46 10: 120 10: 51 5. The Ash-ingredients of the oat are absorbed throughout its entire growth, but in regu]aIr]y diminishing quantity. The gain during the 1st period being 10, that in the 2d period is 9, in the 3d, 8, in the 4th, 5~, in the 5th, 2 nearly. The ratios of gain in ash-ingredients to that in entire dry substance, are as follows, ash-ingredients being assumed as 1, in the successive periods: 1: 122, 1: 27, 1: 16, 1: 23, 1: 19. Accordingly, the absorption of ash-ingredients is not proportional to the growth of the plant, but is to some degree accidental, and independent of the wants of vegetation. .Recapitulation.-Assuming the quantity of each proximate element in the ripe plant as 100, it contained at the end of the several periods the following amounts: Albuminolds. 27~01o 4 5 " 57" 90 c '100 " 216 PFber. 18~lo 81 It 100 " 100 " 100 " Fat. 20~lo 50" 85 " 100 " 100 ", Amyloids. 15~ lo 47 " 70 " 92 " 100 " Ash. 290 1o 55" 79 " 95 " 100 " I. Period, II. " III. a IV. ", V. " COMPOSITION IN SUCCESSIVE STAGES. 'The gain duing each period was accordingly as follows: Fiber. Fat. Amyoids. Albuminolds. Ash. I. Period, 1801o 2031o 1501so 27010o 2901o II. " 63" 30" 32" 18" 26" III. " 19 " 35 " 23 i 12" 24 IV. " 0" 15" 22" 33" 16" V. " 0". 0" 8" 10" 5" 100" 100" 100" 100 " 100 6.-As regards the individual ingredients of the ctsh, the plant contained at the end( of each period the following amounts,-the total quantity in the ripe plant being taken at 100. Corresponding results from Bretschlneider enclosed in () are given for comparison. Stilphusic Pho.ph oric Acidl. Alci. Pe r cent. Per ceit. 2 0 ( 42) 23 ( 23) 52 42 .52 } (5 4) 43 }'( 63) 90 (39) 91 (74)r 100 (100) 100 (100) The gaia (or loss, indicated by the minus si(gn- ) in these ash-ingredients during each period is given below. Silica. Stlphucric P. hoAphoric Lime. Magnzeeia. Potash. Acid. Acid. Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. I. Period, 18 ( 22) 20 ( 42 ) 23 (23) 3') ( 31 ) 24 (31) 39 ( 42 ) 23} 2 19} 28} 52 48 31 } III. " 29 (35) 0 (2) 31 (40) 21 ( ) 16 (24) 21 ( 47 ) IV. " 23 (15) 3S (-5X) 18 (10) 20 (-9*) 26 ( 4 ) 9 (11 ) V. " 7 (28) 10 ( 56) 9 (27)'1 ( 17 ) 16 (23) 0 (-5*) 100 (100) 100 (100) 100 (100) 100 (100) 100 (103) 100 (100) These two independent investigationls could hardly give all the discordant results observed on comparing the above figures, as the simple consequence of the unlike mode of conducting them. We observe, for example, that in the last period Arendt's plants gathered less silica than in any other-only 7~1 o of the whole. On the other hand, Bretschneider's crop gained more silica in this than in any * In these instances Bretschneider's later crops contained less sulphluiuc acid, lime, and potash, than the earlier. This result mlay be due to the washing of the crop by rains, but is probably caused by unequal development of the several plots. 10 217 Silica. Per cenit. I. Period, 18 ( 22) ]I. " 41 5 III. "1 70 IV. 93 ( 72) V. " 100 (100) Lime. Magnesia. Per cent. Per celnt. 30 ( 31) 24 ( 31) 79 t ( 83) 4,2} ('.3) 99 ( 7 4) 84 ( 77) .100 (100) 100 (100) Potash. Per cent. 39 ( 42) - 70~ t ( 89) 100 (100) 100 (951) HOW CROPS GROW. other single period, viz.: 28010. A similar statement is true of phosphoric acid. It is obvious that Bretschneider's crop was taking up fixed matters much more vigorously in its last stages of growth, than were Arendt's plants. As to potas% we observe that its accumulation ceased in the 4th period in both cases. It is, Qn the whole, plain that we cannot safely draw from these interesting researches any very definite conclusions as to the rate and progress of assimilation and growth in the oat plant, beyond what have been already pointed out. C.-Translocation of substances In the Plant.-The translocation of certain matters from one part of the plant to another is revealed by the analyses of Arendt, and since such changes are of interest from a physiological point of view, we may recount them here briefly. It has been mentioned already that the growth of the stem, leaves, and ear, of the oat plant in its later stages probably takes place to a great degree at the expense of the roots. It is also probable that a transfer of amyloids, and certain that one of albuminoids, goes on from the leaves through the stem into the ear. Silica appears not to be subject to any change of position after it has once been fixed by the plant. Chlorine likewise reveals no noticeable mobility. On the other hand phosphoric acid passes rapidly from the leaves and stem towards or into the firuit in the earlier as well as in the later stages of growth, as shown by the following figures: 1,000 plants contained in the various periods, quantities (grams) of phosphoric acid as follows: 1st Perid. 2d Perod. 3d Perod. 4t Period. 5th Period. 3 lower joints of stem 0.47 0.20 0.21 0.20 0.19 2 middle " " - 0.39 1.14 0.46 0.18 Upper joint " - 0.66 1.73 0.31 0.39 3 lower leaves " 1.05 0.70 0.69 0.51 0.35 2 upper leaves " 1.75 1.67 1.18 0.74 0.59 F>~~~r~ 2.36 5.36 10.67 12.52 218 COMPOSIlqON IN SUCCESSIVE STAGES. Observe that these absolute quantities diminish in the stem and leaves after the 1st or 3d period in all cases, and increase very rapidly in the ear. Arendt found that sulphuric acid existed to a much greater degree in the leaves than in the stem, throughout the entire growth of the oat plant, and that after blossoming the lower stem no longer contained sulphur in the form of sulphuric acid at all, though its total in the plant considerably increased. It is almost certain, then, that sulphuric acid originates, either partially or wholly, by oxidation of sulphur or some sulphurized compound, in the upper organs of the oat. Magnesia is translated from the lower stem into the upper organs, and in the fruit, especially, it constantly increases in quantity. There is no evidence that lime moves upward in the plant. On the contrary, Arendt's analyses go to show that in the ear during the last period of growth, it diminishes in quantity, being, perhaps, replaced by magnesia. As to potash, no transfer is fairly indicated except from the ears. These contained at blossoming (period III) a maximum of potash. During their subsequent growth the amount of potash diminished, being probably displaced by magnesia. The data furnished by Arendt's analyses, while they indicate a transfer of matters in tihe cases just named and in most of them with great certainty, do not and cannot from their nature disprove the fact of other similar changes, and cannot fix the real limits of the movements which they point out. 219 DIVISION II. THE STRUCTURE OF THE PLANT AND OFFICES OF ITS ORGANS. CHIAPTER I. GENE R ALIT I ES. We have given a brief description of those elements and compounds which constitute the plant in a chemical sense. They are the materials-the stones and timbers, so co speak-out of which the vegetable edifice is built. It is important in the next place to learn how these building materials are put together, what positions they occupy, what purposes they serve, and on what plan the edifice is constructed. It is impossible for the builder to do his work until he tias mastered the plans and specifications of the architect. So it is hardly possible for the farmer with certainty to contribute in any great, especially in any new degree, to the upbuilding of the plant, unless he is acquainted N ith the mode of its structure and the elements that form it. It is the happy province of science to add, to the vague and general information which the observation and experience of generations has taught, a more definite and particular knowledge,-a knowledge acquired by study purposely and carefully directed to special ends. An acquaintance with the parts and structure of the plant is indispensable fcr understanding the mode by which 220 ORGANS' OF THE PLANT. it derives its food from external sources, while the ingenious methods of propagation practiced in fruit and flower culture are only intelligible by the help of this knowledge. ORGANISM OF THE PLANT. - We have at the outset spoken of organic matter, of organs and Organization. It is in the world of life that these terms have their fittest application. The vegetable and animal consist of numerous parts, differing greatly from each other, but each essential to the whole. The root, stem, leaf, flower, and seed, are each instruments or organs whose co-operation is needful to the perfection of the plant. The plant (or animal), being thus an assemblage of organs, is called an Organism; it is an Organized or Organic Structure. The atmosphere, the waters, the rocks and soils of the earth, are mineral matters; they are inorganic and lifeless. In inorganic nature, chemical affinity rules over the transformations of matter. A plant or animal that is dead, under ordinary circumstances, soon loses its form and characters; it is gradually consumed by the atmospheric oxygen, and virtually burned up to air and ashes. In the organic world a something, which we call the VFital Principle, resists and overcomes or modifies the affinities of oxygen, and ensures the existence of a continuous and perpetual succession of living forms. The organized structure is characterized and distinguished from mineral matter by two particulars: 1. It builds up anti increases its own mass by appropriating external matter. It assimilates surrounding substances. It growts by the absorption of food. 2. It reproduces itself. It comes from, and forms again a seed or germ. ULTIMATE AND COMPLEX ORGANS.-In our account of the Structure of the Plant we shall first consider the elements of that structure-the Primary Organs or Vegetable Cells-which cannot be divided or wounded without ex 221 HOW CROPS GROW. tinguishing their life, and by whose expansion or multiplication all growth takes place. Then will follow an account of the complex parts of the plant-its Compound Organs -which are built up by the juxtaposition of numerous cells. Of these we have one class, viz.: the Roots, Stems, and Leaves, whose office is to sustain and nourish the Individual Plant. These may be distinguished as the Fegetative Organs. The other class, comprising the Flower and Fruit, are not essential to the existence of the individual, but their function is to maintain the Race. They are the Reproductive Organs. CHAPTER IL THE PRIMARY ELEMENTS OF ORGANIC STRUCTURE. ~ 1. THE VEGETABLE CELL. One of the most interesting discoveries that the micro-< scope has revealed, is, that all organized matter originates in the form of minute vesicles or cells. If we examine by the microscope a seed or an egg, we find nothing but a cell-structure-an assemblage of little globular bags or vesicles, lying closely together, and more or less filled with solid or liquid matters. From these cells, then, comes the frame or structure of the plant, or of the animal. In the process of maturing, the original vesicles are often greatly modified in shape and appearance, to suit various purposes; but still, it is always easy, especially in the plant, to find cells of the same essential characters as those occurring in the seed. 222 so* ELEMENTS OF ORGANIC STRUCTURE. Cellular Plants.-In those classes of vegetation which depart structurally to the least degree from the seed, and which belong to what are called the "lower orders,"* we find plants which consist entirely of cells throughout all the stages of their life, and indeed many are known which are but a single cell. The phenomenon of red snow, frequently observed in Alpine and Arctic regions, is due to a microscopic one-celled plant which propagates with great ski1,rapidity, and gives its color to the surface of the snow. In the chem ist's laboratory it is often observed that, in the clearest solutions of salts, like the sulphates of soda and Fig. 27. magnesia, a flocculent mould, sometimes red, sometimes green, most often white, is formed, which, under the microscope, is seen to be a vegetation consisting of single cells. Brewer's yeast, fig. 27, is nothing more than a mass of one or few-celled plants. In the mushrooms and sea-weeds, as well as in the moulds that grow on damp walls, or uipon bread, cheese, etc., and in the brand or blight which infests many of the farmer's crops, we have examples of plants formed exclusively of cells. All the plants of higher orders we find likewise to consist chiefly of globular or angular cells All the growing parts especially, as the tips of the roots, the leaves, flowers, and fruit, are, for the most part, aggregations of such minute vesicles. If we examine the pulp of fruits, as that of a ripe apple or tomato, we are able, by means of a low magnifier, to distinguish zn ~ ~ ~~~~~~Fig. 28. the cells of which it almost entirely con- Fig. 28. sists. Fig. 28 represents a bit of the flesh of a ripe pippin, * Viz.: the Cryptogam, including Moulds, and Mushrooms, (Pingi,) Mosses, Ferns, and Sea-Weeds, (Alge). 223 — 6 HOW CROPS GROW. magnified 50 diameters. The cells mostly cohere together, but readily admit of separation. Structure of the Cell.-By the aid of the microscope it is possible to learn something with regard to the internal structure of the cell itself. Fig. 29 exhibits the appearance of a cell from the flesh of the Jerusalem Artichoke, magnified 230 diameters; externally the membrane, or w all of the cell, is seen in section. This membrane is filled and distended by a transparent liquid, the sap or free water of vegetation. Within the cell is observed a round body, a- f zf, b, which is called the iutcleus, and upon this is seen a smaller nucleolus, c. Lining the interior of the cell-membrane and connected with the nucleus, is a yellowish, F.2 9 turbid, semi-fluid substance of mucilagi i 29 nous consistence, a, which is designated the protoplasm, or formcative layer. This, when more highly magnified, is found to contain a vast number of excessively minute granules. By the aid of chemistry the microscopist is able to dissect these cells, which are hardly perceptible to the unassisted eye, and ascertain to a good degree how they are constituted. On moistening them with solution of iodine, and afterward with sulphuric acid, the outer membranethe cell-wall-shortly becomes of a fine blue color. It is accordingly cellulose, the only vegetable substance yet known which is made blue by iodine after, and only after, tile action of sulphurio acid. At the same time we observe that the interior, half-liquid, protoplasm, has coagulated and shrunk together,-has therefore separated from the cell-wall, and including with it the nucleus and the smaller granules, lies in the center of the cell like a collapsed bladder. It has also assumed a deep yellow or brown color. If we moisten one of these cells with nitric acids the cell-wall is not affected, but- the liquid penetrates it, 224 ELEMENTS OF ORGANIC STRUCTURE. coagulates the inner membrane, and colors it yellow. In the same way this membrane is tinged violet-blue by chlorhydric acid. These reactions leave no room to doubt that the slimy inner lining of the cell is chiefly an albuminoid. It has been termed by vegetable physiologists the protoplasm or formative layer, from the fact that it is the portion of the cell first formed, and that from which the other parts are developed. The protoplasm is not miscible with or soluble in water. It is contractile, and in the living cell is constantly changing its figure, while the granules commonly suspended in it move and circulate as in a stream of liquid. If we examine the cells of any other plant we find almost invariably the same structure as above described, provided the cells are young, i. e., belong to growing parts. In some cases cells consist only of protoplasm and nucleus, being destitute of cell-walls during a portion or the whole of their existence. In studying many of the maturer parts of plants, viz.: such as have ceased to enlarge, as the full-sized leaf, the perfectly formed wood, etc., we find the cells do not correspond to the description just given. In external shape, thickness, and appearance of the cell-wall, and especially in the character of the contents, there is indefinite variety. But this is the result of change in the original cells, which, so far as our observations extend, are always, at first, formed closely on the pattern that has been explained. Vegetable Tissue.-It. does not, however, usually happen that the individual cells of the higher orders of plants admit of being obtained separately. They are attached together more or less firmly by their outer surfaces, so as to form a coherent mass of cells-a tissue, as it is termed. In the accompanying cut,. fig. 30, is shown a highly magnified view of a portion of a very thin slice across a young cabbage stalk. It exhibits the outline of the ir 10* 225 HOW CROPS GROW. regular empty cells, the walls of which are, for the most part, externally united and appear as one, a. At the points indicated by b, cavities between the cells are seen, called intercellular spaces. A slice across the potato-tuber, (see fig. 52, p. 277,) has a similar appearance, except that the ~ ~ clsaesarh, &3 and it would be scarcely possible to dissect them grains swell, and the cells, in consequence, separate cal result of which is to make the potato mealy. A thin slice of vegetable ivory (the seed of PAy under the microscope, dry or moistened with water, presents no trace of cell-structure, the cells being united as one; however, upon soaking in sulphuric acid, the mass softens and swells, and the individual cells are at once revealed, their surfaces separating in six-sided outlines. Form of Cells. In the soft, succulent parts of plants, the cells lie loosely together, often with considerable intercellular spaces, and have mostly a rwnded outline. In denser tissues, the cells are crowded together in the least possible space, and hence often appear six-sided when seen in cross-section, or twelve-sided if viewed entire. A piece of honeycomb is an excellent illustration of the appearance of many forms of vegetable cell-tissue. The pulp of an orange is the most evident example of cell-tissue. The individual cells of the ripe orange may be easily separated from each other, as they are one-fourth of an inch or more in length. Being mature and incapable of further growth, they possess neither protoplasm nor 226 Fig. 30. ELENTS OF ORGANIC STRUCTURE. nucleus, but are filled with a sap or juice containing citric acid and sugar. In the pith of the rush, star-shaped cells are found. In ... 1com 11o _m o1 the.cel l ar..lng.an tbread4ike. In the so-called frog-spittle they are cylindrical and attached end to end. In the bark of many trees, in the stems and leaves of grasses, they are square or rectanglar cotton:fiber, ilax and hemp consist of long and slender cells, fig. 31. Wood is ^ ~~at the eds1u andW adhering togethert by their sides. Fig. 49, c. h., p. 271. Each cotton-fiber is a single cell which forms an external appendage to the seed-vessel of the cot ton plant. When it has lost its free water of vegetation and become air-dry, its sides collapse and it resembles a twisted strap. A, in fig. 31, exhibits a portion ofa cotton-fiber highly magnified. The flax-fiber, firom the inner bark of the flax g stem, b, fig. 31, is a tube of thicker walls and smaller bore than the cotton-fiber, and hence is more durable than cotton. It is very flexible, and even when crushed or bent short, retains much of its original tenacity. Hemp-fiber closely resembles flax-fiber in appearance. Thickening of the Cell.'Membrane.-The growth of the cell, which, when young, always has a very delicate outer membrane, often..Jl i results in the thickening of its walls by the interior deposition of cellulose and lignin. This thickening may / take place regularly and uniformly, or interruptedly. The flax-fiber, b, fig. 31, is an example of nearly uniform thickening. The irregular deposition of cellulose is shown in fig. 32, which exhibits a section from Fig. 32. the seeds (cotyledons) of the common nasturtium, (Tropaolum majus). The original membrane is coated interiorly with several distinct and successively-formed linings, which are not continuous, but are irregularly developed. Seen in section, the 227 . HlOW CROPS GROW. thickening has a waved outline, and at points, the original cell-mern. brane is bare. Were these cells viewed entire, we shou-ald see at these points, on the exterior of the cell, dots or circles appearing like orifices, but being simnply the unthickened portions of the cell-wall. The cells in fig. 32 exhibit each a central nucleus surrounded by grains of aleurone. Cell Contents. -Besides the protoplasm and nucleus, the cell usually contains a variety of bodies, which have been, indeed, noticed already as ingredients of the plant, but which may be here recapitulated. Many cells are al together empty, and consist of nothing but the cell-wall. Such are found in the bark or epidermis of most plants, and often in the pith, and although they remain connected with the actually living parts, they have no proper life in themselves. All living or active cells are distended with liquid. This consists of water, which holds in solution gum, dextrin, inulin, the sugars, organic acids, and other less important vegetable principles, together with various salts, and constitutes the sap of the plant. In oil-plants, droplets of oil occupy celtain cells, fig. 17, p. 90; while in numerous kinds of vegetation, colored and milky juices are found in certain spaces or channels between the cells. The water of the cell comes from the soil, as we shall hereafter see. The matters, which are dissolved in the sap or juices of the plant, together with the semi-solid proto plasm, undergo transformations resulting in the production of solid substances. By observing the various parts of a plant at the successive stages of its development, under the microscope, we are able to trace within the cells the formation and growth of starch-grains, of crystalloid and granular bodies consisting chiefly of vegetable casein, and of the various matters which give color to leaves and flowers. The circumstances under which a cell developes deter mine the character of its contents, according to laws that are hidden from our knowledge. The outer cells of the potato-tuber are incrusted with corky matter, the inner 228 ELEMENTS OF ORGANIC STRUCTURE. ones, most of them, are occupied entirely with starch, fig. 52, p. 277. In oats, wheat, and other cereals, we find, just within the empty cells of the skin or epidermis of the grain, a few layers of cells that contain scarcely anything but albuminoids, with a little fat; while the interior cells are chiefly filled with starch; fig. 18, p. 106. Transformations in Cell Contents.-The same cell may exhibit a great variety of aspect and contents at different periods of growth. This is especially to be observed in the seed while developing on the mother plant. Hiartig has traced these changes in numerous plants under the microscope. According to this observer, the cell-contents of the seed (cotyledons) of the common nasturtium, (Tropceolum majus,) run through the following metamorphoses Up to a certain stage in its development the interior of the cells are nearly devoid of recognizable solid matters, other than the nucleus and the adhering protoplasm. Shortly, as the growth of the seed advances, green grains of chlorophyll make their appearance upon the nucleus, completely covering it from view. At a later stage, these grains,' which have enlarged and multiplied, are seen to have mostly become detached firom the nucleus, and lie near to and in contact with the cell-walL Again, in a short time the grains have lost their green color and have assumed, both as regards appearance and deportment with iodine, all the characters of starch. Subsequently, as the seed hardens and becomes firmer in its tissues, the microscope reveals that the starch-grains, which were situated near the cell-wall, have vanished, while the cell-wall itself has thickened inwardly-the starch having been converts ed into cellulose. Again, later, the nucleus, about which, in the meantime, more starch-grains have been formed, undergoes a change and disappears; then the starch-grains, some of which have enlarged'vhile others have vanished, are found to be imbedded in a pasty matter, which has the reactions of an albuminoid. From this time on, the 229 HOW CROPS GROW. starch-grains are gradually converted from their surfaces inwardly into smaller grains of aleurone, which, finally, when the seed is mature, completely occupy the cells. In the sprouting of the seed similar changes occur, but in reversed order. The nucleus reappears, the aleurone dissolves, and even the cellulose stratified upon the interior of the cell, fig. 32, wastes away and is converted into soluble food (sugar?) for the seedling. The Dimensions of Vegetable Cells are very various. A creeping marine plant is known-the Cauterpaprolifera, fig. 33,-which consists of a single cell, though it is often a foot in length, and is branched with what have the appearance of leaves and roots. The pulp of the orange consists of cells which are one-quarter of an inch or more in diameter. Every fiber of cotton is a single cell. In most 230 Fig. 33. ELEMENTS OF ORGANIC STRUCTURE. cases, however, the cells of plants are so small as to require a powerful microscope to distinguish them,-are, in fact, no more than 1-1200th to 1-200th of an inch in diameter; many are vastly smaller. Growth.-The growth of a plant is nothing more than the aggregate result of the enlargement and multiplication of the cells which compose it. In most cases the cells attain their full size in a short time. The continuqus growth of plants depends, then, chiefly on the constant and rapid formation of new cells. Cell-multiplication.-The young and active cell always contains a nucleus, (fig. 34, b.) Such a cell may produce a new cell by division. In this process the nucleus, from which all cell-growth appears to originate, is observed to re a~ mob solve itself into two parts, then the protoplasm, a, begins to contract or in:-,: fold across the cell in a line correspond __:_'__- r~ing with the division of the nucleus, until //2' the opposite infolded edges meet-like Fig 34. the skin of a sausage where a string is tightly tied around it,-thus separating the two nuclei and inclosing each within its new cell, which is completed by a further external growth of cellulose. In one-celled plants, like yeast, (fig. 35,) the new cells thus formed, bud out from the side of the parent-cell, and before they obtain full size become entirely detached from it, or, as in higher plants, the new cells remain adhering to the old, forming a tissue. Fig. 35. In free cellformnation nuclei are observed to develope in the protoplasm of a parent cell, which enlarge, surround themselves with their own protoplasm and cell-membrane, and by the resorption or death of the parent cell become independent of the latter. 231 HOW CROPS GRBW. The rapidity with which the vegetable cells may multi. ply and grow is illustrated by many familiar facts. The most striking cases of quick growth are met with in the mushroom family. Many will recollect having seen on the morning of a June day, huge puff-balls, some as large as a peck measure, on the surface of a moist meadow, where the day before nothing of the kind was noticed. In such sudden growth it has been estimated that the cells are produced at the rate of three or four hundred millions per hour. Permeability of Cells to Liquids.-Although the highest magnifying power that can be brought to bear upon the membranes of the vegetable cell fails to reveal any apertures in them,-they being, so far as the best-assisted vision is concerned, completely continuous and imperforate, -they are nevertheless readily permeable to liquids. This fact may be elegantly shown by placing a delicate slice from a potato-tuber, immersed in water, under the microscope, and then bringing a drop of solution of iodine in contact with it. Instantly this reagent penetrates the walls of the unbroken cells without perceptibly affecting their appearance, and being absorbed by the starch-grains, at once colors them intensely purplish-blue. The particles of which the cell-walls and their contents are composed, must be separated from each other by distances greater than the diameter of the particles of water or of other liquid matters which thus permeate the cells. ~ 2. THE VEGETABLE TISSUES. As already stated, the cells of the higher kinds of plants are united together more or less firmly, and thus constitute what are known as VEGETABLE TISSUES. Of these, a large number have been distinguished by vegetable anat 232 ELEMENTS OF ORGANIC STRUCTURE. omists, the distinctions being based either on peculiarities of form or of function. For our purposes it will be necessary to define but a few varieties, viz, Cellular Tissue, Woody Tissue, Bast-Tissue, and Vascular Tissute. Cellular or Cell-Tissue is the simplest of all, being a mere aggregation of globular or polyhedral cells whose wialls are in close adhesion, and whose juices commingle more or less in virtue of this connection. Cellular tissue is the groundwork of all vegetable structure, being the only form of tissue in the simpler kinds of plants, and that out of which all the others are developed. The term parenchyma is synonymous with cell-tissue. Wood-Tissue, in its simplest form, consists of cells that are several or many times as long as they are broad, and that taper at each end to a point. These spindle-shaped cells cohere firmly together by their sides, and "break joints" by overlapping each other, in this way forming the tough fibers of wood. Wood-cells are often more or less thickened in their walls by depositions of cellulose, lignin, and coloring matters, according to their age and position, and are sometimes dotted and perforated, as will be explained hereafter, fig. 53, p. 278. Bast-Tissue is made up of long and slender cells, similar to those of wcod-tissue, but commonly more delicate and flexible. The name is derived from the occurrence of this tissue in the bast, or inner bark. Linen, hemp, and all textile materials of vegetable origin, cotton excepted, con. sist of bast-fibers. Bast-cells occupy a place in rind, corresponding to that held by wood-cells in the interior of the stem, fig. 49, p. 271. Prosenchyma is a name applied to all tissues composed of elongated cells, like those of wood and bast. Parenchyma and prosenchyma insensibly shade into each other. Vascular Tissue is the term applied to those unbranched nbes and Ducts which are found in all the higher orders 233 HOW CROPS GROW. of plants, interpenetrating the cellular tissue. There are several varieties of ducts, viz., dotted lducts, ringed or annular ducts, and spiral ducts, of which illustrations will be given when the minute structure of the stem comes under notice, fig. 49, p. 271. The formation of vascular tissue takes place by a simple alteration in cellular tissue. A longitudinal series of adhering cells represents a tube, save that the bore is obstructed with numerous transverse partitions. By the removal or perforation of these partitions a tube is developed. This removal or perforation actually takes place in the living plant by a process of absorption. CHAPTER IIL THE VEGETATIVE ORGANS OF PLANTS ~ 1. THE ROOT. The RooTs of plants, with few exceptions, from the first moment of their development grow downward, in obedience to the force of gravitation. In general, they requires a moist medium. They will form in water or in moist cotton, and in many cases originate from branches, or even leaves, when these parts of the plant are buried in the earth or immersed in water. It cannot be assumed that they seek to avoid the light, because they may attain a fill development without being kept in darkness. The 234 THE VEGETATIVE ORGANS OF PLANTS. action of light upon them, however, appears to be unfavorable to their fimnctions. The Growth of Roots occurs mostly by lengthening, and very little or very slowly by increase of thickness. The lengthening is chiefly manifested toward the outer extremities of the roots, as was neatly demonstrated by Wigand, who divided the young root of a sprouted pea into four equal parts by ink-marks. After three days, the first two divisions next the seed had scarcely lengthened at all, while the third was double, and the fourth eight times its previous length. Ohlerts made precisely similar observations on the roots of various kinds of plants. The growth is confined to a space of about I6, of an inch from the tip. (Linnea, 1837, pp. 609-631.) This peculiarity adapts the roots to extend through the soil in all directions, and to occupy its smallest pores, or rifts. It is likewise the reason that a root, which has been cut off in transplanting or otherwise, never afterwards extends in length. Although the older parts of the roots of trees and of the so-called root-crops acquire a considerable diameter, the roots by which a plant feeds are usually thread-like and often exceedingly slender. Spongloles.-The tips of the rootlets have been termed spongioles, or spongelets, from the idea that their texture adapts them especially to collect food for the plant, and that the absorption of matters from the soil goes on exclusively through them. In this sense, spongioles do not exist. The real living apex of the root is not, in fact, the outmost extremity, but is situated a little within that point. Root-Cap.-The extreme end of the root usually consists of cells that have become loosened and in part detached from the proper cell-tissue of the root, which, therefore, shortly perish, and serve merely as an elastic cushion or 235 HOWV CROPS GROW. cap to protect the true termination or living point of the root in its act of penetrating the soil. Fig. 36 represents | I. | Substance~~~~~~~~~~~~~~~. I' ~~-i~~ 9 AI91-1 m.-ROOT CROPS. 26lPotatoes................... 31 3.7459.8 1.6 4.5 2.319.1 6.6 2.3 2.8 27|Artichok es............ 1.... 5.16 65.4.... 2.7 3.5 16.0 3.2... 2.4 28 Beets...................... 15 6.86 53.1 14.8 5.1 4.6 9.6 3.3 3.3 6.( 29 Sugar beets................. 44 4.35 49.4 9.6 8.9 6.314.3 4.7 3.5 2.0 30Turnips..................... 15 8.2839.311.4 3.910.413.314.3 2.4 4.1 31 Tinnips*....................2 7.2050.6 3.8 2.1 13.417.4 6.0 1.1 6.4 32Ruta-bagas.................. 2 7.6851.2 6.7 2.6 9.715.3 8.4 0.5 5.1 33Carrots...................... 10 6.27 36.722.1 5.310.712.5 6.4 2.0 3.2 34 Chicory..................... 7 5.21 40.4 7.7 6.3 8.7 14.5 9.2 6.1 3.7 85,Sugar beet-heads t............1 4.0329.624.411.0 9.1 12.8 7.6 2.0 0.5 IV.-LEAVES AND STEMS OF ROOT CROPS. 36,Potatoes, August........... 3 8.92 14.5 2.7 16.8 39.0 6.1 5.6 8.0 4.6 37 " October........... 1 5.12 6.3 0.8 22.6 46.2 5.5 5.5 4.2 3.0 38Beets....................... 6 15.96 29.1 21.0 9.711.4 5.1 7.4 4.8 11.3 39 Sugaar beets.................. 7 17.49 22.1 16.8 18.3 19.7 7.4 8.0 3.1 5.7 40 Turnips..................... 16 13.68 22.9 7.8 4.5 32.4 8.9 9.9 3.8 8.2 41 Kohl-rabi....................1 16.8714.4 3.9 4.0 33.3 10.411.710.5 3.9 42 Carrots....................... 13.5714.1 23.1 4.633.0 4.7 7.9 5.6 1 43 Chicory...................... 1 12.46 60.0 0.7 3.2 14.3 9.09 0 1.01 1.7 44 Cabbage.................... 2 10.81 48.6 3.9 3.315.3 15.8 8.5 1.2 2.5 45 Cabbage stalk............... 1 6.46 43.9 5.5 4.1 11.3 20.9 11.8 1.1 1.2 V.-REFUSE AND MANUFACTURED PRODUCTS. 46 Sugar beet cake.............. 7 3.1536.6 8.4 5.625.310.2 3.9 6.2 4.8 a. Common cake...........2 3.03 25.0 12.7... 27.2 12.9 5.8.... 13.0 b. Residue of maceration.... 2 3.53 35.3 9.4 11.8 27.9 6.0 2.3.... 0.9 c. Residue from Centrifugal 1.1145 9.8.... 25. 13.0 6.5 machine.............. 3.11 45.5 9.8 25.3 13.0 6.5 47Beet molasses............... 3 11.28 71.1 10.5 0.4 8.0 0.5 2.1 0.710.1 48Molassesslumpl I............ 1 19.02 89.8 0.9 0.1 1.7.... 1.6 49 Raw beet sugar.............. 1 1.43 33.3 28.0.... 8.5.... 22.9 0.9 5.8 50 OPotato slump:.............. 1 11.1046.3 6.6 8.8 8.220.0 7.3 3.4 2.1 51 Potato fiber................... 4 0.99 15.6.... 7.4 17.8 23.9.... 3.1 1.3 52,Potato juice............... 2 23.45 69.5.... 3.5 1.016.3 3.6 0.1 7.5 53]Potato skins~............... 3 9.5972.0 0.7 $.7 9.6 3.4 0.4 2.7 2.1 54!Fine wheat flour............ 1 0.4736.0 0.9 8.2 2.8 52.0............ B5 Rye flour.................... 1 1.97 38.4- 1.8 8.0 1.0 48.3. 56 Barley flour................. 1 2.33 28.8 2.5 13.5 2.8 47.3 3.1 57 Barley dust**............... 1 5.6218.9 1.4 7.7 2.528.9.... 20.0.... 58 Maize meal.................... 28.8 3.5 14..9 6.3 45.0............ 59iMillet meal.................. 1 1.35 19.7 2 8 25.8.... 47.3 2.7........ 60 Buckwheat grits.............2 0.72 25.4 5.9 12.9 2.3 48.1 1.7.... 1.6 61 Wheat bran................ 6.43 24.0 0. 6 16.8 4.7 51.8... 1.1.... 62 Rye bran.................... 1 8.22 27.0 1.3 15.8 3.5 47.9............ 63 Brewer's grains............. 2 5.17 4.2 0.8 10.1 11.6 38.0 0.8 32.2.... 64 Malt..................... 1 2.78 17.3.... 8.4 3.8 36. 5.... 33.2.... 65 Malt sprouts................6 34.9....... 1.4 1.5 21.0 6.3 29.5... 66 Wine grounds.............. 1 4.60 53.4 0.5 3.2 15.5 15.5 7.8.... 0.5 67 Grape skins................. 2 4.04 49.4 2.2 6.1 13.0 20.8 4.4 3.5 0.6 68Beer........................ 1.....37.5 7.8 4.9 2.232.7....10.2... 69 Grape must................. 6..... 62.8 0.9 5.6 4.9 17.7 6.5 1.31 0.6 70 Rape cake................ 2 6.5924.3 0.111.510.936.9 3.3 8.7 0.2 I___________ * White turnips in the original, but apparently no special kind. t Probably the crowns of the roots, removed in sugar-making.: The residue after fermentIng and distilling off the spirit. I Refuse of starch manufacture. ~ Undiluted. I Prom boiled potatoes. ** Refuse in making barley grits. II 377 I I I HOW CROPS GROW. COMPOSITION OF THE ASH OF AGRICULTUIRAL PLANTS AND PRODUCTS. Substanoe. a1 a a X |i ~~N -1 --- -~~~~a V.-REFUSE AND MANUFACTURED PRODUCTS. 71 Linseedcake............... 1 6.24 23.3 1.415.9 8.8 35.2 3.4 6.5' 0.6 72 Poppy cake.................1 10.60 20.8 4.5 4.3 28.1 37.8 2.0 4.8 73 Walnut cake............... 1 5.36 33.1.12.2 6.7 43.8 1.2 1.6 0.2 74 Cotton seed cake...........1 6.9535.4... 4.3 4.648.3 1.1 4.0 VI.-STRAW. 75 Winter wheat............... 12 4.96 11.5 2.9' 2.6 6.2 5.4 2.9 66.3'... 76 Winter rye..................6 4.8118.7 3.3 3.1 7.7 4.7 1.9 58.1.... 77 Winter spelt................2 5.56 11.2 0.4 0.9 4.8 6.3 1.871.4. 78 Summer rye.................3 5.55 23.4... 2.8 8.9 6.5 2.6 55.9... 79 Barley...................... 17 5.10121.6 4.5 2.4 7.6 4.3 3.753.8.... 80 Oats..................... 6 5.12,22.0 5.3 4.0 8.2 4.2 3.5 48.7.... 81 Maize...................... 1 5.491135.3 1.2 5.510.5 8.1 5.238.0.... 82 Peas........................ 21 5.7421.8 5.3 7.7 37.9 7.8 5.6 5.7 6.1 83 Field bean.................. 4 7.12144.4 3.8 7.8 23.1 7.0 0.2 5.413.8 84Garden bean................ 5 6.06137.1 6.0 5.227.4 7.8 3.6 4.7 5.2 85lBuckwheat.................. 6 6.1546.6 2.2 3.6 18.411.9 5.3 5.5 7.7 86; Rape....................... 12 4.58125.6 10.3 5.7 26.5 7.0 7.1 6.7 12.4 S7TPoppy...................... 1 7.86 38.0 1.3 6.5,30.2 3.5 5.1 11.4 2.5 VII.-CHAFF, ETC. 88 Wheat....................1 10.73 9.1 1.8 1.3 1.9 4.3... 81.2.... 89 Spelt........................ 2 9.0 9.5 0.3 2.5 2.4 7.3 2.3-74.2.... 0 Barley.................... 1 14.23 7.7 0.9 1.310.4 2.0 3.0 70.8.... W1 Oats............... 1 9.22 13.1 4.8 2.6 8.9 0.3 2. 59.9.... 32 Maize cobs.................5.. 647.1 1.2 4.1 3.4 4.4 1.926.4 43 Flax seed hulls............. 1 6.62131.1 4.3 2.8 29.6 2.8 4.8 17.2 6.1 VIII.-TEXTILE PLANTS, ETC. 94 Flax Straw................... 8 3.7136.9 5.1 7.122.3 11.5 5.3 6.0 4.0 95Rotted flax stems........... 2 2.40 9.0 4.8 5.451:4 5.9 3.1 13.8... 96Flax fiber................... 3 0.67 3.3 3.2 5.463.6 10.8 2.7 6.2 0.4 97 Entire flax plant............ 2 4.30 34.2 4.8 9.0 15.5 23.0 4.9 2.6 5.9 98 Entire hemp plant........... 2 4.C60 18.3 3.2 9.6 43.411.6 2.8 7.6 2.5 99 Entire hop plant............ 1 9.87 26.2 3.8 5.8 16.0 12.1 5.4 21.5 4.6 100 Hops....................... 12 6.80 37.3 2.2 5.5 16.9 15.1 2.6 15.4 3.4 101 Tobacco..................... 7 24.0827.4 3.710.5.37.0 3.6 3.9 9.6 4.5 IX.-LITTER. EIeath....................... Broom (Spartium).......... Fern (Aspidium)........... 3couring rush (Fquisetum)... 3ea-weed (s.s8).......... Beech leaves in autumn...... ak 1 4.... Fir " (Pinus sylvestris) Red pine leaves (Pinus Pz ea) Reed (Arundovhrag.)....[?ra) Down grass (Psamma area3edge (Carex)............... 1Rush (Jncus)............... Bulrush (Scips)............ X.-GRAINS AND SEEDS OF AGRICULTURAL PLANTS. 116 Wheat..................... 78 2.07 31.1 3.5 12.2 3.1146.2 2.4 1.7.... 117 Rye...................... 14 2.0.3 30.91 1.8 10.9 2.7147.5 2.3 1 5.. 118 Barley...................... 34 2.55 21.9 2.8 8.3 2.5 32.8 2.3127.21.... 119 Oats........................ 20 3.07 15.9 3.8 7.3 3.8120.7 1.6146.4.... I 4 4 7 3 5 0 0 9 3 2 8 2 41 0 4 5 1 3 0 7 4 4 8 8 6 3 7 6, i i 378 k I I II Ii, 5.3 8. 2.5 12. 4.5 7. 0.5 2. 24.0 9. 0.6 6. 0.6 4. .... 9. 2. 0.2 1. .4.0 3. 7.3 4. 6.6 6. 10.3 3. 18.8 17' 1 14.0 12.5 13.9 44.9 48.6 41.4 15.2 5.9 16.5 5.3 9.5 1 7.2 5. 8. 9. 2. 3. 4. 8. 16. 8. 2. 7. 6. 6. 6. 4. 3. 5. 6. 24. 3. 4. 4. 2. 2. 3. 3. 8. 5. 35. 10. 6.1 53. 1. 33. 30. 13.1 70.1 71. 18. 31. 10. ,43. 2.1 2.7 10.2 5.7 10.1 0.4 .i.i .... i 'i.6 14.2 .... 10 10 1 1 1 10 I I 11 ill 11 11 11 11 8 2 5 2 8 6 1 1 1 1, I 11 7 2 4.51 13. 2.25 36. 7.01 42. 23.77 13. 14.39 14. 6.75 5. 4.90 3. 1.40 10.1 5.82 1. 4.69 8. 29. 8.08:3,3. 5. 30136. 8.651 9. I 'X., APPENDIX. COMPOSITION OF THE ASH OF AGRICULTURAL PLANTS AND PRODU(.TB. II~ ~ ~ ~ ~~T Substnce.. X.-GRAINS AND SEEDS OF AGRICULTURAL PLANTS. l20 Spelt with husk...~.. R......2 4.2017.3 1.8 5.8 2.6 20.0 2.6 44. O... 121 Maize.......................8 1.4227.0 1.514.6 2.744.7 1.1 2.2.... 122 Rice with husk.............8 7.8418.4 4.5 8.6 5.147.2 0.6 0.6.... 12 "husked.................3 0.39 23.3 4.813.4 2.9 51.0 0.6 3.0.... 124 Millet with husk............2 4.4911.9 1.0 8.4 1.0 23.4 0.2'52.3.... 125 " husked................ 1 1.42 18.9 5.818.6.... 53.6 1.5........ 126,Sorhum.................. 1.8( 20.3 3.3 14.8 1.3 50.9.... 7.5.... 127lBuc~kwheat.................. 12 1.07 23.1 6.213.4 3.3 48.0 2.1.... 1.7 128 Rape seed............... 15 4.24 23.5 1.1 12.2 13.8 43.9 3.6 1.1 0.3 129,Flax............... 3 3.6532.2 1.813.2 8.440.4 1.1 1.1 0.1 1301Hemp "............... 2 5..48 20.1 0.8 5.6 23.5 36.3 0.2 11.8 0.1 131 Poppy....................1 6.1213.6 1.0 9.535.431.4 1.9 3.2 4.4 132 Mada 1....ay 9.5 11.215.4 7.7 55.0. 133 Mustard..................3 4.30 15.9 5.8 10.2 18.8 39.0 4.7 2.4 0.4 134]Beet............... 1 1 5.66 18.7 17.3]18.9 15.6 15.5 4.2 2.1 9.4 135 Turnip "................1 3.98 21.9 1.2 8.7 17.440.2 7.1 0.7.... 136 1Carrot "................1 8.50 19.1 4.8 6.7 38.8 15.8 5.6 5.3 3.3 137]Peas.....................30 2.81 40.4 3.7 8.0 4.2 36.3 3.5 0.9 2.3 138Vetches................... 1 2.4030.6'10.6 8.5 4.838.1 4.1 2.0 1.1 139 Field Beans................. 6 3.45 40.5 1.2 6.7 5.2 39.2 5.1 1.2 2.9 140 Garden beans.............. 9 3.06 44.1 2.9 7.5 7.7 30.4 3.8 0.8 0.9 141 Lentils...................... 1 2.06 27.8 9.9 2.0 5.1 29.1.... 1.1 8.3 142Lupines..................... 1.... 33.517.8 6.2 7.825.5 6.8 0.9 1.8 143Clover seed.................. 3 4.11 37.3 0.612.2 6.23835 4.7 2.4 1.3 144 Esparsette seed.............. 1 4.47,28.6 2.8 6.6 31.6 23.9 3.2 0.8 1.1 XI.-FRUITS AND SEEDS OF TREES, ETC. 145 Grape seeds.................. 2 2.81 28.6.... 8.6 33.9 24.0 2.5 1.1 0.3 146 Alder.......................2 5.14 37.6 1.6 8.0 30.7113.0 3.4 3.2 0.1 147 White pine................. 1.... 21.8 7.1 16.8 1.5 39.7.... 11.7 0.3 148 Red pine................... 1.... 22.4 1.3 15.1 1.9 46.0.... 10.4... 149 Beech nuts.................. 1 3.30 22.8 10.0 11.6 24.5 20.8 2.2 1.9 0.5 150Acorns...................... 2.... 64.5 0.7 5.4 7.016.2 2.8 1.1 1.7 151 Horse-chestnut............. 2 2.36 58.9.... 0.5 11.6 22.4 1.4 0.2 6.4 152 " green husk... 2 4.3876.4.... 1.0 10.0 6.3 1.4 0.6 5.6 153 Apple, entire fruit........... 1.... 35.7 26.1 8.8 4.1 13.6 6.1 4.3... 154 Pear, 1... 54.7 8.5 5.2 8.015.3 5.7 1.5.... 155 Cherry, " "...........1... 51.9 2.2 5.5 7.516.0 5.1 9.0 1.1 156 Plum, " ".... 59.2 0.5 5.5 10.0,15.1 3.8 2.4.... XII.-LEAYES OF TREES. 157 Mulberry..................3 3.5319.6.... 5.4 25.7 10.2' 0.5'33.5 0.1 158 Horse-chestnut, spring.......2 7.17 38.8.... 3.9 21.3 23.4 6.0 2.9 3.8 159 " autumn...... 1 7.5219.6.... 7.840.5 8.2 1.7 13.9 4.1 l00[Walnut, spring............. 17.72 42.7.... 4.6 26.9 21.1 2.6 1.2 0.5 161 " autumn............1 7.01 26.6... 9.8 53.7 4.0 2.7 2.0 0.8 162 Beech, summer.............2 4.8318.5 1.8 8.636.5 7.8 3.1 15.2 1.2 163 " autumn............... 6 6.75 5.2 0.6 6.0 44.9 4.2 3.7 33.9 0.4 164 Oak, summer............... 1 4.60 33.1.... 13.5 26.1 12.2 2.7 4.4 0.1 165 " autumn................ 1 4.90 3.5 0.6 4.048.6 8.1 4.430.9.... 166 Fit autumn...............1 1.4010.1.... 9.941.416.4 4413.1 4.4 167,Rea pine, autumn........... 1 5.82 1.5..... 2.3 15.2 8.2 2.8 70.1,.... XIII.-WOOD. 168Grape................... 8 2.75 29.8 6.7 6.8 37.3 12.9 2.7 0.8 0.8 169 Mulberry................. 1 1.60 6.5 14.3 5.7 57.3 2.2 10.3 3.6 4.2 170 Birch........................ 2 0.31111.6 5.8 8.9,60.0 8.5 0.3 4.8 0.6 171 Beech, body-wood...........[ 2 0.65116.1 3.4110.8[56.4 5.3 1.0 4.7 0.l 379 I I i HOW CROPS GROW. COMPOSTION OF THE AsH OF AGRICULTURAL PLANTS AND PI,.)DUCT& XII-WOOD. 1 1.0515.2 2.1.8 45.8 11.6 0.7' 6.7 0.1 1 1.4514.1 2.210.8 48.012.3 1.2 9.8 0.1 a 2... 10.0 3.6 4.873.5 5.5 1.4 1.1 0.2 1... 19.8... 7.5 54.0 9.3 1.6 3.1.... 1 3.31 19.4 5.2 51.0 21.7 0.7 1.4 1 2.99 15.3.. 8.1 55.9 12.2 3.2 2.9 0.3 5.... 14.0 0.4 7.558.413.1 1.5 2.0 0.1 1.... 11.4 5.610.150 816.4 3.1 0.7 0.6 1....24.1 2.1 10.0 37.9 9.6 5.4 6.2 6.7 1.... 21.913.7 7:747.8 3.3 1.3 3.1.... I1.... 35.8 6.0 4.229.9 4.9 5.3 5.3 1.5 2 1.2912.0 1.6 5.7 71.0 4.6 2.9 1.8 0.2 1 0.25 5.2 26.8 6.2 47.9 5.1 3.0 2.0 4.0 2 0.28 15.3 9.9 5.9 50.1 5.5 3.0 6.0 0.2 6 0.31 11.8 4.6 9.1 50.1 5.8 2.3 15.0 0.4 1 0.3215.3 7.724.527.1 3.6 1.7. 3.6 0.6 Beech, small wood.......... " brush................ Oak, body-wood........[ bark " small branches with Horse-chestnut twigs, autu'n Walnut twigs, autum n..... Poplar, young twigs......... Willow,,.... Elm,........ Elm, body-wood....::':."::' Linden................. Apple tree................... Red pine.................... White pine.................. Fir....................... Larch........................ 177 17 17. 17 17' 171 178 18 19 18: 18 18~ 18( 18r 188'Birc h........................33 3.8 5.4[ 8.245.6 7.3 1.3'20.1 1.3 18.9. Beech.....t......1.... 14.7 0.4 0.2157.9 0.4 1.3118.0.... 190l Horse-chestnut, young, aut'n t 6.57 24.2.... 4.0 61.3 7.0 1.1 1.1 1.2 191 Walnut, 1 " t6.4011.6.... 10.670.1 5.9 0 2 0.7 0.4 192Elm.......................... 2.2101 3.272.7 1.6 0.6 8.9... l93Linden t....................1.... 16.1 5.7 8.060.8 4.0 0.8 2.3 1.2 1941Redpine.................. 1 2.81 5.3 4.2 4.7162.4 -2.6 1.015.7 0.2 195]Whitepi re................1 3.30 8.0 3.2 3.0{69.8 2.5 1.6 8.4 1.0 196 Flr.......................... 8 2.01 3.0 1.0 1.4143.7 8.3 0.881.1 0.1 i 2I IIL 380 9 Squbstance. k X. —BARK. -1 I, t APPENDIX. TABLE II. C," —OSITION OF FRESH OR AIR-DRY AGRICULTURAL P IODUCTS, giving the average quantity of Water, Sulphur, Ash, and Ash-ingredients, in 1,000 parts of substance, by Prof. W'OLFF. .. 2 1 u ~~~ ~~~ ~~ ~~, I.-HAY. Meadow hay.................. 144 66.617.1 4.7 3.31 7.7 4.1 3.419.7 5.311.7 Deadripehay............. 144 66.2 5.0 1.9 2.3 8.5 2.9 0.541.8 3.82.7 Rede clover.................... 160 56.519.5 0.9 6.919.2 5.6 1.7 1.5 2.12.1 White clover................. 160 60.310.6 4.7 6.019.4 8.5 5.3 2.7 1.92.7 Swedish clover............... 160 46.515.7 0.7 7.1 14.8 4.7 1.9 0.6 1.3.. Lucern.................. 160 60.015.2 0.7 3.528.8 5.1 3.7 1.2 1.1 2.6 Esparsette.................... 160 45.317.9 0.8 2.614.6 4.7 1.5 1.8 1.4.. Greenvetches................ 160 73.430.9 2.1 5.019.3 9.4 2.7 1.3 2.31.5 Green oats.................... 145 61.8 24.1 2.0 2.0 4.1 5.1 1.7 20.5 2.5 1.5 )DDER. 1.6 1.11 2.7 1.5 1.2 6.9 1.9 0.4 0.6 2.2 2.2 0.8 2.1 0.4 0.9 0.5 1.6 1.7 0.8 8.4 1.1 0.6 0.8 2.0 2.3 0.8 7.5 1.1 0.4 0.6 1.2 1.7 1.0 8.2 0.9 0.8 0.6 1.2 1.4 0.6 4.7 0.8 0.6 0.5 1.1 1.4 0.5 5.5 0.7 0.4 0.7 1.6 2.3 0.7 7.0 1.2 0.1 0.7 1.4 2.2 0.710.8 0.8 0.4 0.3 1.1 1.7 0.4 9.4 1.2 0.1 0.5 0.7 1.6 0.412.3 0.6 0.1 0.5 1.2 2.4 0.2 5.2.... ... 1.9 2.5 1.3 0.8 6.7 1.5 0.2 1.6 4.6 1.3 0.4 0.4 0.5 1.1 1.4 4.4 2.0 1.2 0.6 0.4 0.2 1.6 3.2 1.0 0.4 0.1 0.3 0.2 1.0 8.5 1.5 1.1 0.4 0.3 0.2 0.7 3.7 1.2 0.4 0.5 0.3 0.5 0.6 8.5 0.9 0.2 0.4.... 0.5 1.1 4.1 2.0 0.6 0.3 0.5 ... 1.1 3.9 1.8 0.5 0.4 0.2 0.5 0.6 3.1 1.2 2.2 0.4 1.C m.-ROOT CROPS. Potato........................750 9.4 5.6 0.1 0.4 0.2 1.8 0.6 0.2 0.30.2 Artichoke.................... 800 10.3 6.7.... 0.3 0.4 1.6 0.3.... 0.2... Beet.......................... 883 8.0 4.3 1.2 0.4 0.4 0.8 0.3 0.2 0 50.1 Sugar beet............... 816 8.0 4.0 0.8 0.7 0.5 1.1 0.4 0.3 0.2.. Turnip........909 7.5 3.0 0.8 0.3 0.8 1.0 1.1 0.2 0.30.4 White turnip*............915 6.1 3.1 0.2 0.1 0.8 1.1 0.4 0.1 0.4... Kohl-rabi................. 877 9.5 4.9 0.6 0.2 0.9 1.4 0.8 0.1 0.5... Carrot........................ 860 8.8 3.2 1.9 0.5 0.9 1.1 0.6 0.2 0.30.1 Sugar beet-headst............ 840 6.5 1.9 1.6 0.7 0.6 0.8 0.5 0.1 0.1... Chicory...................... 800 10.4 4.2 0.8 0.7 0.9 1.5 1.0 0.6 0.4 * No special variety? t Crowns of sugar beet roots. 0 3 6 5 5 6 3 6 6 4 I 381 ,tance. Meadow gmss, in blossom. Young gmss................. Rve — mss..................... Timthy..................... OtherbgeT nes........ Oats, ni 0 ad...... ' in 10,380m.. rley beginning t' inblossom....... neat, bevnning i head... , in lossom............ Rye fodder... Hungarian Red cover. White clov'r................. Swedish v............... Lucern...................... ESDarsette................... A?ithyllig vulnera7ia.......... Green vetches............... 11 pea,,.::::.:.:...:....:, - " rape. 23.3 20.7 21. 21. 21. 17. 16. 22. 22. 22. 21. 16. 23. 13. 13. 10. 17. ii. 12. 15. 13. 13. F 6. ii. 5. 6. 7. 7. 6. 8. 5. 7. 5. 6. 8. 4. 2. 3. 4. 4. 1. 6. 5. . 4. so 70 0 15 so 5 0.6 0.4 0.7 0.8 0.7 0.8 0.4 0.7 0.3 0.5 6. 0.6 6' 0.3 i6,.6 HOW CROPS GROW. COMPOSITION OF FRESH OR AIR-DRY AGRICULTURAL PRODUCTS Subs~~~nce. ~ ~ u.~~ ~ ~'.2~ Slubstana.~ ~ ~ ~.' ~ IV.-LEA'VE% AND STEMS OF ROOT CROPS. Potato tops, end of August... 825 15.6 2.3 0.4 2.6 5.1 1.0 0.9 1.2 0.7 0.1) "1 "1 first of October.. 770 11.8 0.7 0.1 2.7 5.5 0.6 0.6 0.5 0.40.5 Beet tops..................... 907 14.8 4.3 3.1 1.4 1.7 0.8 1.1 0.7 1.70.5 Sugarbeettops.............897 18.0 4.0 3.0 3.3 3.6 1.3 1.4 0.6 1.0 Turnipatops................898 14.0 3.2 1.1 0.6 4.5 1.3 1.4 0.5 1.2605 oh-rabitops...............850 25.3 3.6 1.0 1.0 8.4 2.6 3.0 2.6 1.0... Carrot'tops...................808 26.1 3.7 6.0 1.2 8.6 1.2 2.1 1.5 1.9 1.4 Chicory tops.............850 18.711.2 0.1 0.6 2.7 1.7 1.7 0.2 0.3... Cabbage heads...............885 12.4 6.0 0.5 0.4 1.9 2.0 1.1 0.1 0.30.5 Cabbage stems.............820 11.6 5.1 0.6 0.5 1.3 2.4 0.9 0.2 0.1... V. —NUFACTURED PRODUCTS AND REFUSE. Sugar beet cake...........692 9.7 3.6 0.8 0.5 2.5 1.0 0.4 0.6 0.5 a. Common cake....[machine 692 9.3 2.3 1.2.... 2.5 1.2 0.5.... 1.2... b. Residue from Centrifugal 820 5.6 2.6 0.5 1.4 0.7 0.4........... c. Residue of maceration.....885 4.1 1.5 0.4 0.5 1.1 0.3 0.1.... 0.1... Beet molasses.............1 75 93.1 66.2 9.8 0.4 5.6 0.6 2.0 0.6 9.4... Molasses slump*............. 907 17.7 15.9 0.2.... 0.3.... 0.3... Rawbeet sugar............... 43 13.7 4.6 3.8.... 1.2.... 3.1 0.1 0.8 Potato slump*................ 947 5.9 2.7 0.4 0.5 0.4 1.2 0.4 0.2 0.1 Potato fiber t................ 806 1.9 0.3.... 0.1 0.9 0.5... 0.1....... Potato skins:................ 300 67.148.3 0.5 4.5 6.4 2.3 0.3 1.8 1.4... Fine wheat flour.............. 136 4.1 1.5 0.1 0.3 0.1 2.1.............. Rye flour..................... 142 16.9 6.5 0.3 1.4 0.2 8.5........... Barley flour.................. 140 20.0 5.8 0.5 2.7 0.6 9.5 0.6. Barley dusti.................. 113 49.8 9.4 0.7 3.8 1.214.4.... 9.9....... Maize meal.............. 140 9.5 2.7 0.3 1.4 0.6 4.3............... Millet meal................... 140 11.6 2.3 0.3 3.0.... 5.5 0.3........... Buckwheat grits.............. 140 6.2 1.6 0.4 0.8 0.1 3.0 0.1.... 0.1... Wheat bran.............. 135'55.613.3 0.3 9.4 2.628.8.... 0.6....... Rye bran.................... 131 71.4 19.3 0.9 11.3 2.5 34.2. Brewer's grains..............768 12.0 0.5 0.1 1.2 1.4 4.6 0.1'3.9.9. Malt......................... 475 14.6 2.5.... 1.2 0.5 5.3.... 4.8....... Dried malt.................... 42 26.6 4.6.... 2.2 1.0 0.7.... 8.8....... Malt sprouts.................. 92 59.6 20.8.... 0.8 0.9 12.5 3.8 17.7....... Wine-grounds................ 650 16.1 8.6 0.1 0.5 2.5 2.5 1.2.1... Grape skins.................. 600 16.2 8.0 0.4 1.0 2.1 3.4 0.7 0.6 0.1 Beer..........................900 3.9 1.5 0.3 0.2 0.1 1.3 0.1 0.4 0.1.. Wine.................... 866 2.8 1.8.... 0.2 0.2 0.5 0.1 0.1... Rape cake................... 150 56.013.6 0.1 6.4 6.120.7 1.9 4.9 0.1::. Linseed cake................. 115 55.212.9 0.8 8.8 4.719.4 1.9 3.6 0. Poppy cake................... 100 95.419.8 4.3 4.1 26.836.1 1.9 4.6....... Walnut cake.................. 136 46.4 15.4.... 5.7 3.1 20.3 0.5 0.7 0.1... Cotton seed cake............. 115 61.5 21.8.... 2.6 2.8 29.5 0.7 2.5....... YI-STRAW. Winter wheat............... 1141 42.6 4.9 1.2 1.1 2.6' 2.31 1.228.2.... 1.6 Winter rye............... 154 40.7 7.6 1.3 1.3 3.1 1.9 0.8 23.7.... 0.9 Winter spelt.................. 143 47.7 5.3 0.2 0.4 2.3 3.0 0.9 34.1....... Summer rye................. 143 47.6{11.1.... 1.3 4.4 3.1 1.226.6... Barley....................... 140 43.9 9.3 2.0 1.1 3.3 1.9 1.6 23.6.... 13 Oats.......................... 141 4-1.0 9.7 2.3 1.8 3.6 1.8 1.5 21.2.... 1.7 Maize....................... 140 47.2J16.6 0.5 2.6 5.0 3.8 2.517.9,.... 3.9 Peas....................143 49.2 10.7 2.6 8.8 18.6 3.8 2.8 2.8 3.0 0.. Field bean...................180 58.4 25.9 2.2 4.6 13.5 4.1 0.1 3.1 8.1 2.i Garden bean..................J1501 51.5J19.1 3.1 2.7 14.1 4.1 1.8 2.4 2.72.1 * Residue from spirit manufacture. t Refuse of starch manufacture.: From boiled potatoes. H Refuse from making barley grits. 382 ( t i i i i i .4s t II APPENDIX. COMPOSITION OF FRESH OR AIR-DRY AGRIqULTURAL PROD'UCTS. Ii. I Substnce..2 I~.-i I VI.-STRAW. Buck-wheat..............160 51.7 24.1[ 1.1 1.9 9 5 6.1 2.7 2.8 4.0. .Rape................11701 38.0 9.7 3.9 2.1 10.1 2.7 2.7 2.6 4.7 1 Poppy.......................1160 66.0125.1 0.9 4.3,19.9 2.3 3.4 7.5 1.7.... VII.-CHAFF. Wheat.................1138 92.5 8.4.1.7 1.2 1.9 4.0.. 75.1.... 0.8 Spelt.............. 130 82.7 7.9 0.2 2.1 2.0 6.0 19 61.... Barley................. 1401122.4 9.4 1.1 1.6 12.7 2.4 3.7 86.7. Oats...................... 143 79.0 10.4 3.8 2.1 7.0 0.2 2.0 47.3 Maize cobs..............115 5.0 2.4 0.1 0.2 0.2 0.2 0.1 Flax seed hulls..........120 58.3181 2.5 1.6172 1.6 2.8 10.0 3.6 1.8 VIII.-TEXTILE PLANTS, ETC. Flax straw.................. 140 31.911.8 1.6 2 3 8.3 4.3 2.0 2.2 1.5 1.4 Rotted flax stems........... 100 21.6 1.9 1.0 1.211.1 1.3 0.7 3.0.... 0.2 Flax fiber...............100 6.0 0.2 0.2 0.3 3.8 0.7 0.2 0.3........ Entire flax plant...........250 32.311.3 1.5 2.9 5.0 7.4 1.6 0.8 1.9.... Entire hemp plant........300 28.2 5.2 0.9 2.7 12.2 3.3 0.8 2.1 0.7 Entire hop plant......... 250 74.0 19.4 2.8 4.3 11.8 9.0 3.8 15.9 3.4 2.0 Hops..................120 59.8 22.3 1.3 2.1 10.1 9.0 1.6 9.2 0.2 4.8 Tobacco.................. 180 197.5 54.1 7.3 20.7 73.1 7.1 7.7 19.0 8.8.... IX.-LITTER. Heath.....................200 36.11 4.8 1.9 3.0 6.8 1.8 1.6 12.7 0.8.... Broom(Sprtium)..........160 18.9 6.9 0.5 2.8 3.2 1.6 0.7 1.9 0.5.... Fern (As.dium)....... 160 58.9 25.2 2.7 4.5 8.3 5.7 3.0 3.6 6.0.... Scouring rusht(iseum).. 140 204.4 27.0 1.0 4.7 25.6 4.1 12.9 110.0 11.7.... Sea-weed (Fucus)......... 180 118.0 17.1 2.311.2 16.4 3.7 28.3 2.0 11.9.... Beech leaves............... 150 57.4 3.0 0.3 3.4 25.8 2.4 2.1 19.5 0.2.... Oak leaves................. 150 41.7 1.5 0.2 1.720.2 3.4 1.8 12.9.... Fir leaves(Pinussylvestris).. 160 11.8 1.2.... 1.1 4.9 1.9 0.5 1.5 0.5... Red pine leaves (P/nusea) 160 48.9 0.7.... 1.1 7.4 4.0 1.4 34.3....... Reed (Arundophrag.)......[180 38.5 3.3 0.1 0.5 2.3 0.8 1.1 27.5. Sedge (Carex)............140 69.5 23.1 5.1 2.9 3.7 4.7 2.3 21.8 3.9. Rush (Juews)..............1140 45.6116.7 3.0 2.9 4.3 2.9 4.0 5.0 6.5.... Bulrush (Scirpus)............140 74.4 7.2 7.7 2.2 5.4 4.8 4.2 32.2, 3.9.... X.-GRAINS AND SEEDS OF AGRICULTURAL PLANTS. Wheat.................143 17.7 5.5 0.6 2.2 0.6 8.2 0.4 0.3.... 1.5 Rye........................ 149 17.3 5.4 0.3 1.9 0.5 8.2 0.4 0.3.... 1.7 Barley..................... 145 21.8 4.8 0.6 1.8 0.5 7.2 0.5 5.9... 1.4 Oats.......................140 26.4 4.2 1 0 1.8 1.0 5.5 0.4 12.3.... 1.7 Spelt, with husk........... 148 35.8 6.2 0.6 2.1 0.9 7.2 0.6 15.8. Maize...................... 186 12.3 3.3 0.2 1.8 0.3 5.5 0.1 0.3... 1.2 Rice, with husk........... 120 69.0 12.7 3.1 5.9 3.5 32.6 0.4 0.4........ ~ husked............... 130 3.4 0.8 0.2 0.5 0.1 1.7.... 0.1........ Millet, with husk.......... 130 39.1 4.7 0.4 3.3 0.4 9.1 0.1 20.5.... 1.8 husked.............131 12.3 2.3 0.7 2.3.... 6.6 0.2........... Sorghum................... 140 16.0 4.2 0.5 2.4 0.2 8.1.... 1.2. Buckwheat................. 141 9.2 9 1 0.6 1.2 0.3 4.4 0.2.....0.2.... Rape seed...... 120 37.3 8.8 0.4 4.6 5.216.4 1.3 0.4 0.1 8.2 Fla x "............... 118 32.2 10.4 0.6 4.2 2.7 13.0 0.4 0.4.. 1.7 Hemp.....122 48.1 9.7 0.4 2.7q11.317.5 0.1 5.7 0.1.... Poppy.................147 52.2 7.1 0.5 5.018.516.4.1.0 1.7 2.3... Mustard..............120 37.8 6.0 2.2 3.9 7.1 14.7 1.8 0.9 0.210.1 Beet'~..............140 48.7 9.1. 8.4 9.2 7.6 7.6 2.0 1.0 4.6 0.8 Turnip................. 120 35.0 7.7 0.3 3.0 6.1 14.1 2.5 0.2.... 7.8 Carrot................. 120 74.814.3 3.6 5.029.011.8 4.2 4.0 2.5 2.7 Peas....................1381 24.2 9.8 0.9 1.9 1.2 8.8 0.8 0.2 0.6 2.4 136 20.7 6.3 t 2 1.8 0.6 7.9 0.9 0.4 0.2,.. I 383 4 i i I I I I I I HOW CROPS GROW. COMtION OF FRESH OR AIR-DRY AGRICULTURAL PRODUCTS. F rance. |S||gqI}|W1m i.-GRAINS AND SEEDS OF AGRICULTURAL PLANTS. Field beans..............141 29.6 12.0 0.4 2.0 1.5 11.6 1.5 0.4 0.82.3 Garden beas............. 148 26.1 11.5 0.8 2.0 2.0 7.9 1.0 0.2 0.3 2.5 Lentils....................... 134 17.8 7.7 1.8 0.4 0.9 5.2... 0.2 0.6... Lupines...................... 138 34.0 11.4 6.0 2.1 2.7 8.7 2. 3 0. 6... Clover seed.................. 150 36.9 13.8 0.2 4.5 2.3 12.4 1.7 0.9 0.5.. Esparsette seed............ 160 37.6 10.8 1.1 2.5 11.9 9.0 1.2 0.3 0.4 2.8 XI.-FRUITS AND SEEDS OF TREES, ETC. Grape seeds.............. 120 24.7 7.1... 2.1 8.4 5.9 0.6 0.3 0.1'... Alder "................. 140 44.2 16.6 0.7 8.5 13.6 5.7 1.5 1.4...... Beechnuts.................... 180 27.1 6.2 2.7 3.1 6.7 5.6 0.6 0.5 0.1... Acorns, fresh................. 560 9.6 6.2 0.1 0.5 0.7 1.6 0.2 0.2 0.1... dried............. 158 18.3 11.8 0.1 1.0 1.3 3.3 0.5 0.4 0.3... HIorse-hestnuts, fresh........492 12.0 7.1... 0.1 1.4 2.7 0.2.. 0.8... " green husk.. 818 8.0 6.1... 0.1 0.8 0.5 0.1 0.1 0.4.. Apple, entire frnit............ 840 2.7 1.0 0.7 0.2 0.1 0.4 0.2 0.1...... Pear, " "........... 800 4.1 2.2 0.4 0.2 0.3 0.6 0.2 0.1...... Cherry, " "...................780 4.3 2.2 0.1 0.2 0.3 0.7 0.2 0.4 0.1... Plum, " "............ 820 4.0 2.4... 0.2 0.4 0.6 0.2 0.1...... XIL-LEAVES OF TREES. ) 11.7 2.3... 0.6 0 21.5 8.3 ~,. 0.8 30 0.1 5.9.. 2.4 0 23.2 9.9.. 1.1 0 28.4 7.6.. 2.8 0 12.1 2.2 0.2 1.1. 30 0.5 1.6 0.2 1.8 0 13.8 4.6... 1.9 0 19.6 0.7 0.1 0.8 0 6.3 0.6... 0.6 0 26.2 0.4... 0.6 -WOOD. (AIR-DRY.) 0 23.4 7.0 1.6 1.6 0 13.7 0.9 2.0 0.8 0 2.6 0.3 0.2 0.2 0 5.5 0.9 0.2 0.6 0 8.9 1.4 0.2 1.5 0 12.3 1.7 0.3 1.3 0 5.1 0.5 0.2 0.2 10 10.2 2.0... 0.8 28.1 5.... 1.5 25.5 8.9... 2.0 0 11.0 1.8 0.2 0.6 0 2.1 0.1 0.6 0.1 0 2.4 0.4 0.2 0.1 0 2.6 0.3 0.1 0.2 0 2.7 0.4 0.2 0.7 KIV.-BARK. Grape...................... Mulberry..................... Birch...................... Beech, body-wood........... " small wood................ " brush.................. Oak, body-wood.............. "small branches with bark lorse-chestnut, young wood in autumn................. Walnut...................... Apple tree.................... Red pine...................... White pine.................. Fir.. o..................... Lach......................... Birch..................... 50 11.3 0.4 0.6 0.9 5.2 0.8 0.2 2.' 0.2 Horse-chestnut, young in aut. 150 55.9 13.5... 2.2 34.3 3.9 0.6 20.6 0.7:: Walnut, " { 150 54.4 6.3... 5.8 38.1 3.2 0.1 0.4 0.2 Red pine....................150.9 1.3 1.0 1.1 14.9 0.6 0.2 3.8.0.1. White pine...............150 2.1 2.3 0.9 0.8 19.6 0.7 0.5 2.3 0. F1r.....I.....................150.1 17.1 0.5 0.2 0.2 7.5 1.4 0.1 5.3... l: I \ 384 L I k 6~ 7( 7( . i I. lt I 15 15 1.2 0.1 4.1... 5.0 1.3 0.6 0.8 2.5 0.5 4.2 1.2 4.9 0.6 0.3 0.1 1.1 0.8 0.6 0.2 0.9 0.4 1.8 0.1... 1.3 1.1 10.3 0.1... 1.7 0.4 0.6...... 1.6 0.9 6.1 1.3 0.3 0.8 0.3j... 2.1 0.7 18.4..... i 8.7 3.0 0.6 0.2 7.8 0.3 1.4 0.5 1.5 0.2... 0.1 3.1 0.3 0.1 0.3 4.1 1.0 0.1 0.6 5.9 1.5 0.1 1.2 3.7 0.3 0.1 0.1 5.5 0.9 0.2 0.3 14.3 5.9... 0.2 14.2 3.1 0.8 0.7 7.8 0.5 0.3 0.2 1.0 0.1 0.1 0.1 1.2 0.1 0.1 0.2 1.3 0.2 0.1 0.4 0.7 0.1 0.1 0.1 0.2 0.6 0.4 0.1 **.. LSC L50 L5 L5 LSC L50 L50 i I APPENDIX. TABLE III. DROXIMATE COMPOSITION OF AGRICULTURAL PLANTS AND PRODUCTS, giving the average quantities of Water, Organic Matter, Ash, Album inloids, Carbohydrates, etc., Crude Fiber, Fat, etc., by Professors WOLFF and KNOP.* Substance. I 1 HAY. Meadow hay, medium quality................... 14.3 79.5 6.2 8.2141.3!30.0 2.0 Aftermath.............................. 14.3 79.2 6.5 9.5145.7 l24.0 2.4 Red clover fill blossom........................ 16.7 77.1 6.2 13.4 29.935.8 3.2 " " ripe...............................16.777.7 5.6 9.4 20.348.0 2.0 White clover, full blossom................... 16.7 74.8 8.514.9 34.325.6 3.5 Swedish or Alsike clover (Trfolium hyb2dum) 16.7 75.0 8.3 15.3 29.2130.5 3.3 " clover, ripe............................ 16.7 78.3 5.0 10.2 23.1 45.0 2.2 Lucern, young..o...........................16.7 74.6 8.7 19.7 32.9 22.0 3.3 in blossom.......................16. 76.9 6.414.4 22.540.0 2.5. Sand lucern, early blossom (Medicagointerimedia) 16.7 77.2 6.1 15.2 26.9 35.1 3.0 Esparsette, in blossom......................... 16.7 77.1 6.2 13.3 36.7 27.1 2.5 Incarnate clover, do ( efolium incarnatuem).. 16.7 76.1 7.2 12.2 30.1 33.8 3.0 Yellow " do (Med[cago lupulina)..... 16.7 77.3 6.014.6 36.5 26.2 3.3 Vetches, in blossom.......................... 16.7 75.0 8.314.2 35.3 25.5 2.5 Peas, " "............................16.7 76.3 7.014.336.825.2 2.6 Field spurry, in blossom (Spergula arvensis).... 16.7 73.8 9.5 12.039.8122.0 3.2 " " after blossom......................16.7 75.5 7.8 7.8 41.7 26.0 2.5 -Serradella, " " (Ornithopus sativus).. 16.7 77.7 5.6 14.6 29.2 33.9 1.5 before "................... 16.775.8 7.5 15.337.226.1 1.9 ItalianRyegrass (oiumitaicum).......... 14.3 77.9 7.8 8.7 51.4 16.9 2.8 Timothy (Peumpratense)................. 14.3 81.2 4.5 9.7 48.8 22.7 3.0 Early meadow grass (Poa annua)............ 14.3 83.3 2.4 10.1 47.2 25.9 2.9 Crested dog's tail (Cynosurus cristatus).. 14.3 80.2 5.5 9.5 48.0 22.6 2.8 Soft brome grass (Bromus mollis)......... 14.3 80.7 5.0 14.8 35.0 31.0 1.8 Orchard grass (Dactyls glomerata).......... 14.3 81.1 4.611.6 40.7 28.9 2.7 Barlegrs(orerpaere)...... Barleygrass (Horeumpretens)........... 14.3 80.4 5.3 9.6 42.0 27.2 2.0 Meadow foxtail (Alopecuriispratensss). o 14.3 79.0 6.7 10.6 39.5 29.0 2.5 Oat grass, French rye grass (Arrhenatherun. avenaceum)........................ 14.375.8 9.9.1 35.3 29.4 2. Inglish rye grass (Lollum perenne).......... 14.3 79.2 6.51iO.238.9 30.2 2.7 Harter Schwingel (Festuca.)................. 14.3 81.0 4.7110.4 37.5 33.2 2.9 Sweet-scented vernal grass (Anthacmnthur odoratm)......................... 14.31 80.3 5.4 8.940.231.2 2.9 Velvet grass (Holus lanatus).............. 14.3180.2 5.5 9.936.733.6 3.1 Spear grass, Kentucky Blue grass (Poa prten).............................. 14.380.6 5.1 8.9 39.1 32.6 2.3 Rough meadow grass (Poa trivals)........ 14.3 78.6 7.1 8.4 37.632.6 3.2 Yellow oat grass (Avenaflavesens).......... 14.3 79.8 5.9 6.4 42.6 30.81 2.2 Quaking grass (Briza media)................ 14.3 78.3 7.4 5.2 42.8 30.31 2.6 Average of all the grasses.................. 14.3 79.9 5.8 9.5 41.7287.T 2.6 * Landwirthschaftlicher Katender, 1867, through Knop's Agrictur- Chenmie, 1868, pp. 715-720. This Table is, as regards water and ash, a repetition of Table II, but includes the newer analyses of 1865-7. Therefore the averages of water and ash do not in all cases agree with those of the former Tables. It gives besides, the proportions of nitrogenous and non-nitrogenous compounds, 1. e., Albuminoids and Carbohydrates, etc. It also states the averages of Crude fiber and of Fat, etc. The discussion of the data of this Table belongs to the subjects of Food and Cattle-Feeding. They are, however, inserted here, as it is believed they are not to be found elsewhere in the English language.- t Organic matter here signifies the combustible part of the plant.-11 Carbohydrates, etc., includes fat, starch, sugar, pectin, etc., all in fact of Org. matter, except Albuminoids and Crude fiber.-+ C de fiber is impure cellulose obtained by the processes describ ed on pages 60 and 61. — Fat, etc., is the ether-extract p. i, and contains be. sides fat, wax, chlorophyll, and in some cases resins. 17 I 385 I I. HOW CROPS GROW. I PROXIMATE CjOMPOSITION OF AGRICULTURAL PLA.NTS AND PRODUCTS. I I g - u.' 4 . ~ ~ Winter wheat..........................14.380 5.5 2.030.248.0. Winter rye................................. 14.3825 3.2 1.527.0 54.0 1.3 Winter spelt.............................1479.7 6.0 2.027.750.5 1.4 Winter barley.................................. 14.3 80.2 5.5 2.0 29.8 48.4.4 Summer barley................................. 14.3 78.7 7.0 3.0 32.7 43.0 1.4 with clover................... 14.3 77.7 8.0 6.0 34.7 37.5.7 Oat............................................ 14.3 80.7 5.0 2.538.240.0 2.0 Vetch fodder.................................. 14.3 79.7 6.0 7.5 28.2 44.0 2.0 Pea.................... 14.381.7 4.0 6.535.240.0 2.0 Bean................................... 17.3 77.7 5.0 10.2 33.5 34.0 1.~ Lentil.................................... 14.3 79.2 6.5 14.0 27.2 36.6 2.0 Lulpine........................................ 14.281.4 4.4 4.934.7 41.8 1.5 Maize.......................................... 14.0 82.0 4.0 3.0 39.0 40.0 1.1 CHAFF AN]D HULLS. Wheat.......................................... 14.3 73.7 12.0 4.5 33.2 36.0 1.4 Spelt............................................ 14.377.2 8.5 2.932.841.5 1.3 Rye........................................ 14.3 78.2 7.5 3.528.246.5 1.2 Barley.......................................... 14.3 72.7 13.0 3.0 38.7 30.0 1.5 Oat.................................... 14.3 67.7 18.0 4.0 29.7 34.0 1.5 Vetch........................................ 15.0 77.0 8.0 8.5 32.5 36.0 2.0 Pea....................................14.3 79.7 6.0 8.1 36.6 35.0 2.0 Bean...................................... 15.0 77.0 8.0 10.5 29.5 37.0 2.0 Lupine.................................14.3829 2.8 2.547.2 33.0 2.5 Rape.......................................... 10.3 77.5 8.5 3.540.034.0 1.6 Maize cobs..............................10.383.2 2.8 1.444.0 37.8 1.4 GREEN FODDER. Grass, before blossom...................... 75.0 " after "..................... 69.0 Red clover,before "...................... 8 3. 3 ' full "....78...........03 7 8.0 White " " "..................... 80.5 Swedish clover, early blossom................. 85.0 "' full ".................82.0 Lucern, very young.......................... 81.0 " in blossom............................. 74.0 Sand lucern, early blossom.................72.... 78.0 Esparsette, in "...............[tum) 80.9 Incarnate clover in " (Trfolium incarna- 81.5 Yellow clover, in blossom (Medaiago ltpuina).. 80.0 Serradella, " " (Ornithopus sativu).. 80. 8 Vetches, " "...................... 82.0 Peas, " "......................81. 1 Oats, early blossom............................. 81.0 Rye....................................9..... 72.9 Maize, late end August.......................... 84.3 " early" " "........................9.7 0.5 _"early" [cum) 82.2 Hungarian millet, in blossom (Panicun germanI- 65. 6 Sorghum saccharatum........................0. 74. Sorghum vulgare................................ 77.3 Field spurry in blossom......................... 80.. Cabbage...................................... 289.0 stumps................................8. Field beet leaves................................ 90.5 Carrot leaves.................................. 82. Poplar and elm leaves.......................... 7 0. Artichoke stem...........................8..... 83 0. Rape leaves..................................0 dry tI i 886 Substance. STRAW. I i It i 22.9 29.0 15.5 20.3 17.5 13.5 16.2 17.3 24.0 20.1 18.5 16.9 18.5 18.7 16.2 17.0 7.6 .5 4.6 6.7 32.0 .1 21.6 18.0 9.8 16.1 6.7 14.2 28.0 17.3 75.5 2.1 2.0 1.5 1.7 2.0 1.5 1.8 1.7 2.0 1.9 1.5 1.6 1.5 1.3 1.8 1.5 1.4 1.6 1.1 I.i 2.4 0.9 1.1 2.0 1.2 1.0 1.8 3.6 2.0 2.7 24.5 3.0 2.5 3.3 3.7 3.5 3.3 3.3 4.5 4.5 4.0 3.2 2.7 3.5 3.6 3.1 3.2 2.3 3.3 o.9 1.1 5.9 2.5 2.9 2.3 1.5 1.1 1.9 3 2 6.0 3. 20.0 12.9 15.0 7.7 8.6 8.0 5.7 6.3 7.8 7.0 6.6 8.8 6.7 9.0 7.0 7.6 8.2 8.8 14.9 8.7 10.9 15.0 15..It 11.9 10.4 6.3 12.2 4.6 8.0 15.5 10.6 47.5 7.0 11.5 4.5 8.0 6.0 4.5 6.6 5.0 12.5 9.5 6.5 7.5 6.0 8.1 5.5 5.6 6.5 7.3 5.0 4.7 11 5 1. 3 6 7 5.3 2.0 2.8 1.3 3.0 6.5 3.4 8.0 0. 8 0.7 0.7 0.8 0.8 0.6 0.6 0.6 0.7 0.8 0.6 0.6 0.8 0.4 0.6 0.6 0.5 0.9 0.5 0.5 1.5 1.4 0.7 0.4 0.8 0.5 1.0 1.5 0.8 2.0 t t PROXIMATE COMPOSITION OF AGRICULTURAL PLAN-TS AND PRODoUCTS. substan7ce. |.2g g@gtl4 ROOTS AND TUBERS. Potato......................................... 95.024.1 0.9 2.021.0 1.1 0.3 Jer usalem Artichoke.......................... 80.0 18.9 1.1 2.015.6 1.3 0.5 Turnip Chervil? (Koerbelriibe)................ 76.0 23.1 0.9 3.2 17.0 1.0 0.6 Kohl-rabi...................................... 88.010.8 1.2 2.3 7.3 1.2 0.2 Field beets (about 3 lbs. weight)................ 88.0 11.1 0.9 1.1 9.1 0.9 0.1 Sugar beets (1-2lbs.)............................ 81.5 17.7 0.8 1.015.4 1 3 0.1 Rut-baas (about 3 lbs.)..................... 87.012.0 1.0 1.6 9.3 1.1 0.1 Carrot (about / lb.)............................. 85.0 14.0 1.0 1.5 10.8 1.7 0.2 Giant carrot (1-2 lbs.)........................... 87.012.2 0.8 1.2 9.8 1.2 0.2 Turnips (Stoppelrube).........................91.5 7.7 0.8 0.8 5.9 1.0 0.1 Turnips (Turnipsrube)......................... 92.0 7.2 0.8 1.1 5.1 1.0 0.1 Parsnp......................................... 88.311.0 0.7 1.6 8.4 1.0 0.2 Pumpkin................................ 94.5 4.5 1.0. 1.3 2.8 1.0 0.1 GRAINS AND SEE Rice........................................5 Winter wheat................................... Wheat flour.................................... Spelt........................................... Winter r ye..................................... Rye flour...................................... Winter barley.................................. Summer barley................................ Oats............................................ Maize......................................... Millet......................................... Buckwheat...................................... Vetches....................................... Peas............................................ Beans (field)................................... Lentils......................................... Lupines..................................... Acorns without shell, dry....................... " with " fresh.................... Chestnuts without shell, fresh.................. Madia seed..................................... Flax s e ed....................................... Rape seed..................................... Hemp seed...................................... Poppy s e ed..................................... Horse chestnut................................. REFUSE. Sugar beet cake......................... chine "residue from centrifugal ma "; "* " " " maceration...... Potato slump................................... Rye slump...................................... Maize slump................................... Molasses slump............................... Brewer's grains............................... Malt sprouts.................................... Fresh malt with sprouts........................ Dry malt without sprouts....................... Wheat bran..................................... Rye bran........................................ Rape cake...................................... Linseed cake.................................... Gold of pleasure cake.......................... 5 0 8 0 0 0 5 0 0 5 5 5 5 6 1 8 2 5 9 6 9 0 1 6 2 3 5 0 0 8 5 2 0 0 4 2 7 3 6 8 6 6 5 5 3 2 2 8 1 8 0 6 6 1 5 2 4 0 8 2 1 1 7 5 3 0 5 5 3 1. APPENDIX. 387 S. 14.6 14.4 12.6 14.8 14.3 14.0 14.3 14.3 14.3 14.4 14.0 14.0 14.3 14.3 14.5 14.5 14.5 20.0 56.0 49.2 8.4 12.3 11.0 l.2 14.7 30.0 '84.9 83.6 86.7 81.3 83.7 84.4 83.4 83.1 82.7 83.5 83.0 83.6 83.4 83.2 82.0 82.5 82.0 78.4 43.0' 49.o 86.9 82.7 85.1 83.6 78.3 68.8 0. 2. 0. 3. 2. 1. 2. 2. 3. 2. 3. 2. 2. 2. 3. 3. 3. 1. 1. 1. 4. 5. 3. 4. 7. 1. 7. 13. ii. 10. ii. 10. 9. 9. 12. 10. 14. 9. 27. 22. 25. 23. 34. 5. 2. 3. 22. 20. 19. 16. 17. 10. 1. 1. 0. 1. 2. 2. 1. 4. 23. 6. 8. 4. 14. 28. 28. 28. 14. 6: 2. 0. 3. 0. 16. 3. 1. 8. 7. 10. 5. 6. 15. . 6. 9. ii. 6. 14. 4. 4. 0. 18. 7. 10. 12.1 6.1 4. 6. 3.6 1. 0.6 1.6 1. 17.5 4. 8. 17. 15.0 15. ii. 12. 0.5 1.5 1.2 1.5 2.0 1.6 2.5 2.5 6.0 17.0 3.0 2.5 2.7 2.5 2.0 2.6 6.0 4.32.3 2.5 41.0 37.0 40.0 33.6 41 0 2. 70. 82. 92. 94. 89. 89. 92. 76. 8. 47. 4. 13. 12. 15. ii. 15. 26. 16. 6. 4. 10. 10. 6. 22. 50. 93-. 81. 83. 77. 80. 78. 3. 1. 0. 0. 0. 0. 1. 1. 6. 1. 2. 5.1 4. 7. 7. 6. is. 12. 4. 3. 6. 7. 5. ii. 44. 39. 76. 50. 53. 33. 41. 37. 0.2 0.1 0.1 0.1 0.4 1.2 ,i:4 2 5 1:5 2.5 3.8 3.5 9.0 10.0 8.5 I I t I HOW CROPS GROW. PROXIMATE COMPOSITION OF AGRICULTURAL PLANTS AND PRODUCT. &bstaznce. 1 S.k 411 ' sf- REFUSE. Poppycake................................... 10.081.6 8.432.537.711.4 8.1 Hemp cake............................ 10.5 85.5 4.0 27.0 36.5 22.0 6.1 Beechnut cake............... 10.0 84.8 5.2 24.0 31.3 20.5 7.5 w "without shells..............12.5 79.8 7.7 37.3 36.9 5.5 7.5 Beet molasses..........................16.7t72.5110.8 8.0]64.5[.... Potato fiber........................... 82.6117.1 0.31 0.8115.01 1.i'6 6. CO.FFEE. TEA. j\ Coffee bean.............................12.0 93.0 7.0 10.0 49.0 34.0 12.6 Chocolate bean.......................... 11.0 85.0 4.0 20.0 52.0 13.0 44.0 Black China tea................................ 15.0 79.0 6.0 5.0 32.0 40.0 2.0 Green........................ 15.0 79.0 6.0 5.0 27.0 45.0 2.0 TABLE IV. DETAILED ANALYSES OF BREAD GRAINS. |t~| M |8| 18&&; * | | An2atyst. WHEAT. FromEl sss............. 14.6159.7 7.21.2 1.7 1.6'14.0'Boussingault. " Saxony............ 11.8644 1.4 2.6 2.5 1.615.6 Wunder. America............10.9634 3.81.2 8.3 1.610.8 Polson. Flanders..0.......9.2 10 9.21.0 1.8 1. 14.6 Peligot. "Odessa...........14.359.6 6.31.5 1.7 1.415.2 Tanganrock......... 13.6 57.9 7.91.9 2.3 1.6 14.8 " " Poland............. 21.5534 6.81.5 1.7 1.913.2' " Hungary.........13.462.2 5.41.1 1.7 1.714.5 " " gypt.............20.6 55.4 6.01.1 1.8 1.6 14.8 " RYE. FromHessia.............I1. 6 50.5 8.9 0.9 10.1 1.8 15.0 Fresenius. "France... I'. 11.6156.5 10.2 1.9 3.5 2.2 14.1 Payen. Saxon y..........9.1164.9 0.4 2.3 3.5 1.4 18.3 A. Muller. ". ~......i9.6 56.7 6.4 2.1 8.5 3.3 16.5 Wolff. BARLEY. 10.5 50.3 5.5 2.0 13.6 3.8'15.7 Wolff. 13.2 53.7 4.2 2.6 11.5 2.8 12.0 Polson. From Salzmuinde, Prussaia 9.3 60.4 1.2 2.0 9.7 2.4 15.0 Grouven. OATS. 8.8 55.4 2.516.4. 9.6 2.7114.61A. Muller. 15.7 32.2........ 4.1 12.9lKrocker. 10.2........ 6.11 10.0 2.7 12.6 Anderson. BUCKWHEAT. Tusked, fromVienna...... 2.6178.9 3.810.9 1.0... 12.71Bibra. ""'"............ 3.6 76.7 4.311.3 1.3... 13.7l" " ~.......1 3' 1........13.9 3.5 2.5/13.0/Boussin_anlt. Unhu/ked....... 8.5137.81....... 1 12.0114.2[Horstsorl & Krocker ".............. 9.1145.0 7.1 0.4 22.0 2.4 14.0 Zenneck. MAIZE. From Saxony........... 8.8 58.0 5.3 9.2 4.9 3.2 10.5 Hellriegel. America......... 8.8154.4 2.714.6 15.8 1.712.0OPolson. Galacz........... 9.1149.5 2 9[4.5 20.4 1.811.8 1" " Switzerland...........51.2 6.713.8 12.5... 10.6 Bibra. 4 L tL 388 (i, APPENDIX. DETAILED ANALYSES OF BREAD GArINS. Qs~ i I%1 14S~. 1 - I- 9 S -~ ~ ~ g-, RICE. From Piemont... 7.5........0. 5 0.9 0.5 14.6 Boussingault. Patna.............. 7.2 79.9 1.6 0.1 0.5 0.9 9.8 Polson. Plemont........... 7.8....0.2 3.4 0.3 13.7 P6hgot. East Indies....... 5.9 73.9 2.3 0.9 2.0.... 1 4.0 Bibra. MILLET. Husked. Hagenanu..:.:...... 120.61 1 13.01 2.4 12.2114.01Boussingault. " Nuremberg....... 10.357.0111.08.0 2.0 J...J12.21Bibra. TABLE V. DETAILED ANALYSES OF POTATOES, by GROUEN. (Agricultur-Chemie, 2te A?tf., pp. 495 & 355.) ud. uf Water.................74.95 78.01 76.0alyses !, TABLE VL Hohenheim......................... Moeckern.......................... " 2 lbs..................... Bickendorf, 1 lbs.............. Slanstadt, 2 lbe.................... Lockwitz, 1 Y4, lbs...............7. Tharand, 1~ " manured......... "'2 " ". 81.81.161.15 5.77.1 " 8" ".......... Silesia, unmanured................. manured with nitrate of soda man'd with phosphate of ime AverSge................. 389 .4 t I Analils. 81.5 84.1 81.7 79.5 80.0 80.0 79.9 82.7 81.8 82.1 82.5 84.4 82.q 84.1 81.5 0.87 0.82 0.84 0.90 0.70 0.68 0.65 0.93 1.16 1.14 1.05 1.14 1.42 1.20 0.95 1l.90 9.10 11.21 12.07 12.90 13.37 13.32 12;34 10.15 9.25 8.4G 9.8a 11.5' 9.82 11.~ 3.47 1.33 3.90 1.05 3.86 1.36 5.09 1.52 5.00 1.0 5.21 5.53 3.24 5.77 6.36 q.07 3.96 3.63 4.04 3.1 1.3 0.80 0.99 0.94 0.88 0.70 0.74 0.60 0.79 1.12 1.15 0.93 0.69 0.68 O.T7 6.8 Wolff. Pitthausen. Grouven. Stockhardt && &. .. Bretsclmekler. .&. TABLE VII.-COMPOSITION OF FRUITS, according to FRESENIU ,luble Matters. 00OSE2]~RI~. Goos=B~Rns I 1. Large, red, prickly.....................1854 8.0631.358 0.441 0.969 0.317 1.148 2. Small, red, prickly......................1854 6.030 1.573 0.445 0.513 0.45 9.013 3. " " "...................... 1855 8.239 1.5890.358 0.522 o. 1.212. 4. Medium yellow, nearly smooth..........1854 6.383 1.078 0.578 2.112 0.200 10.351 5. " "'..1855 7.5071.3340.369 2.113 0.277 1.600 6. Large, red, smooth...............1855 6.4831.6640.306 0.843 0.553 9.849 CURRATS. 7. Red, medium, ripe......................1854 4.78 2.31 0.45 0.28 0.54 8.36 8. " "......................1855 6.44 1.84 0.49 0.19 0.57 9.53 9. Very large cherry currants.............. 1855 5.647 1.695 0.356 0.007 0.620 8.35 ,0. White.................................1854 6.61 2.26 0.77 0.18 0.54 10.36 11. "...........................1855 6922.58 0:. 1855 7.692 2.258 0.300 0.560 10.810 12. "...........................1856 7.12 2.53 0.68 0.19 0.70 11.22 STRAW BEWrmus. 13. Wild.......................... 1854 8.247 1.650 0.619 0.145 0.737 6.398 14. "............................ 1855 4.5501.3320.567 0.049 0.603 7.101 15. Ananas........................1855.5751.1330.359 0.119 0.480 9.666 RASPB S. 16. Red, wild.............................. 1854 3.597 1.980 0.546 1.107 0.270 7.500 17. Red, garden..................... 1855 4.7081.356 0.544 1.746 0.481 8.835 18. White, garden..................1855 8.f703 1.115 0.665 1.397 0.380 7.260 baccharose and Fructose. t Expressed as hydrated malic acid. $ Already include SB, Skit8 & 1n8Ob Hattr8. ~ ~I 2.4811 2 0.329 (0.14 ) 8.187 2.442 0.515 (0.069) 2.957 2.529 1.428 (0.07) 3.957 3.380[0.442 0.308 (0.100) 4.130 2.081 0.9 (0.170) 3.036 2.803 0.390 (0.133) 3.193 4.451 0.66 0.69 (0.11) 5.80 4.48 0.72 (0.23) 5.20 3.940 2.380 (0.185) 6.320 4.94' 0.53 (0.12)!.47 4.144 0.24 4.384 4.85 0.51 (0.14) 5.36 6.032 0.299 (0.31 6.331 5.580 0.300 (o.M 5.880 1.960 0.900 (0.154) 2.860 8.460 0.180 (0.134)1 8640 4.106 0.502 (0.296) 4.608 4.520 0.040 (0.081) 4.560 I in Seeds, Skins, etc. water I co 0 rs. (Ann. Ch. u. PA., 101, p. 219.) 85.565 88.030 84.831 86.519 85.364 86.958 85.84 85.27 85.355 84.17 84.806 83.42 87.271 87.019 8.474 83.860 86.557 88.1801 100.000 100.000 100.000 100.0O0 100.000 100.000 100.00 100.00 100.000 100.00 100.000 100.00 100.000 100.000 100.000 100.000 100,000 100.000 O t4 v t.4 o .tt .1 -,- 1 M, " Nlmll i 1I , *. I - _ - —? I COMPOSITION OF FRUITS, according to FRESENIUS. (Arn. C11. u. Solube Matters. I1 !0 ~ a ! 8eed, Slc 8.000 5.210 9.328 12.864 14.043 0.905 16.490 2.592 13.629 1.770 18.30.... 19.10.... 22.93.... ..... * o,*. 7.250 5.480 0.45 13.435 3.244 0.46 13.540 5.730 0.36 13.270 5.182 0.80 10.725 5.780 0.17' 15.190 3.250 0.684 16.148 2.852 1. 03! 6.550 4.190 0 10.413 3.329 1 11.910 3.540 1.99( 13.098 3.124 0.97' ncluded in Seeds, 4 ~~~~~~~~~~~ #o 19. BLACKBERRIEs. 4.444 20. WHORTLEBERRIES. 5.780 21. MULBLRRIEs. Black. 9.191 GRAPES. 22. Austrian white...................1854 13.780 23. Kicinherger.185510.590 24. Riessling, Oppenheim................1855 13.51 25. "..................1855 15.14 26. Riessling, Johannisberg................1850 19.24 27. Assmanshauser, red....................1856 17.28 CHERRIES. 28. Sweet, pale-red.........................185413.11 9 29. Sweet, white............................1855 8.568 30. Sweet,black............................ 1855 10.700 31. Sour,...................................1855 8.772 PLURS. 32. Green Gage, common, yellow, Ifirabele.1854 3.58 .3. do.med. size, yellowish greeu,1?eineclaude.'54 2.960 34. do.large, green, very sweet &juicy 1855 3.405 35. Blue, medium size, tart.................1854 1.99. 36. Black, fair flavor........................1855 2.2 5 PRUNES. 37. Comln, moderately sweet, w'ght 16 grms..'55 5.793 38. Large Italian, very sweet, w'ght 19 grms..'55 6.730 ~ Saccharose and Fructose. t Expressed as hydrat I ) iJ .t 4 1.18i 1.341 1.86( 1.020 0.82a 0.71 0.5C 0.66 0.75 0.351 0.961 0.56C 1.27q 0.581 0.96C 0.87s 1.27C 1.331 0.952 0.841 ,d m~ 0.51(t 1.444 0.41 0.794 0.555 0.85 0.394 2.031 0.566 0.832 0.498 0.360 0.662 0.220 0.377 4.07 3.46 2.95 0.9031 2.286 0.60 3.529 0.83! 1.010 0.670 0.600 0.825 1.831 0.56! 0.197 5..772 0.57 0.477 10.475 0.31 0.401 11.074 0.39 0.475 2.313 0.49 0.426 5.851 0.553 0.785 3.646 0.73 0.832 4.105 0.5 ic acid. $ Already COMPOSITION OF FRUITS, according to FRESENIUS. (Ann. Ch. u. Ph., 101, p. 219.) -~~~~~~~~~~~~beM~&&d,Sis&Iou6Mtes ae a. g.~ 4: gs: I 2ue ~ V, E *.l I ~ ~ ~ ~ u~~~u 9 5.415 5.266 APIICOTS. 39. Handsome, rather large, weight 47 grms..'54 40. Very delicate, large, weight 60 grms....1854 PEAcHEs. 100.000 100.000 100. 0 100. 0 100.00 100.00 100.00 100.00 100.0 41. Large Holland..........................6...60. 1855 42. " "........................... 1855 APPLES. 43. Lar,e, EnlishReinette................. 1853 44.' "................ 1 45. " " ".................4 6 18m 46. White table apple.................1854 47. Borsdorfer.......................13...... 185 48. White, Msatapfel 185 3....................... 1853 49. English Winter Goldpearmain................ 1853 PEARs. 50. Sweet, red pear......................... 1854 0.0I71 1.95 0.38 1.a ............ ............ ......... 0.390 3.42a 3.518 * Baccharose and Fructose. t Expressed as hydrated malic acid. t Already included in Seeds, Skins. etc. I i iII I ii I I 7 1 1 i 0 co co to & Iuble Hatte?v. Soluble Matter8. 4 :2 99 il :x el 0.967 0.148 .944 1.002 O. i 2.420 ., -t N I - 9 .s (0.071) (0.104) I rz 4.300 3.216 84.966 82.011 0.832 5.92.9 0.820 0.389 9.283 0.754 0.463 6.313 0.422 11.058 0.913 1.14 1.53 .89 .76 9.61 2.7 1.580 0.612 1.565 0.734 9.390 4.6 4.270 6.7 (0.042) 5.620 84.990 (0.163) 9.184 76.546 1.80 0.52 7 61 0.22 0.45 6.47 0.36 0.22- 2.72 _ 0.44 1 1 - . 6.85 3.35 5.11 11.58 14.70 14.96 12.00 15.07 13.34 15.95 2.39 3.27 3.00 2.96 2.44 4.53 2.18 86.03 82.031 1 82.041, 85.04 82.49 81.87 9.25 5.96 6.83 7.58 7.61 8.98 10.36 0.53 0.39 0.85 1. 0.61 1.01 0. "i:i 1 05 1:16 ...... ...... ...... 'd.bW) (0.03) (0.03) ...... ...... ...... .260 3.281 0. .237 4.409 0. 1.340 (0.05 5.150 83.95 00.000 7. .0 .9 51. 11 11,......................... m 7. c 2.87 0. 0. 4.1 00.000 4 P-' AP'PENDIX. TABLE VIII. FRUITS.ARhANGED INq THE ORDER OF THEIR CONTENT OF SUGAR, (average,) FRESENiUS. per cent. Currants..................... 6.1 Prunes...................... 6.3 Gooseberries................ 7.2 Red pears................... 7.5 Apples.................... 8.4 Sour cherries............... 8.8 Mulberries................ 9.2 Sweet cherries.............. 10.8 Grapes...................... 14.9 per cent. Peaches..................... 1.6 Apricots......................1.8 Plums...................1... 2.1 Reineclaudes............... 3.1 Mirabelles....................3.6 Raspberries.................. 4.0 Blackberries...................... 4.4 Strawberries............7......5.7 Whortleberries...............5.8 TABLE IX. FRUITS ARRANGED IN THE ORDER OF THEIR CONTENT OF FREE ACID EXPRESSED AS HYDRATE OF MALIC ACID, (average,) FRESENIUS. per cent. Blacklcrries.................. 1.2 Sour cherries................. 1.3 Plums........................ 1.3 Whortleberries............... 1.3 Strawberries..................1.3 Gooseberries.................. 1.5 Raspberries.................. 1.5 Mulberries.................... 1.9 Curraits,..................... 2.0 Red pears.................. 0.1 Mirabelles.......................... 0.6 Sweet cherries.................0.6 Peaches.................... 0.7 Grapes.................7.... 0.7 Apples..................8.......0.8. Prunes........................0.9 Reineclaudes.................0.9 Apricots.................... 1.1 TABLE X. FRUITS ARRANGED ACCORDING TO TIlE PROPORTIONS BETWEEN ACID, SUGAR, PECTIN AND GUM, ETC., (averages,) FRESENIUS. Acid. Sugar. ' 1 1.6 1 1.7 1 2.3 1 2.7 1 3.0 1 3.4 1 3.7 1 4.3 1 4.4 1 4.9 1 4.9 1 6.2 1 6.9 1 7.0 1 11.2 1 17.3 1 20.2 1 94.6 Plums................................ Apricots............................... Peaches............................. Raspberries............................ Currants............................... Reineclaudes.......................... Blackberries........................... Whortleberries........................ Strawberries......................... Gooseberries.......................... Mulberries............................ Mirabelles............................ Sour cherries.......................... Prunes............................... Apples................................ Sweet cherries....................... Grapes................................ Red pears............................. 17* 398 Pectin, Gum, etc. 3.1 6.4 11.9 1.0 0.1 11.8 1 2 .4 0.1 0.8 1.1 9.9 1.4 4.4 5.6 2.8 2.0 44.4 HOW CROPS GROW. TABLE XI. FRUITS ARRANGED ACCORDING TO THE PROPORTIONS BETWEEN W.ATER, SOLUBLE MATTERS AND INSOLUBLE MATTERS, (averages,) FRESENIuS. Water. SolubleMatters. f7soluble Mattcrs. Raspberries....................... Blackberries.................... Strawberries..................... Plums............................ Ctirrants.......................... Whortlebenries.................... Gooseberries..................... Mirabelles........................ Apricots.......................... Red pears........................ Peaches........................... Prunes........................... Sour cherries..................... Mulberries........................ Apples........................... Reineclaides.................. Cherries.......................... Grapes............................ TABLE XII. PROPORTION OF OIL IN VARIOUS AIR-DRY SEEDS, according to IERJOT. (Knp's Agricultur Cemie, p. 725.) (The air-dry seeds contain 10-12 per cent of hygroscopic water.) Co;za, common............4045 Gold of Pleasure...............35 Schirmraps............. 44 Waterimelon...................... 36 red India............. 40 Charlock.........................1542 " white"............. 40 Orange........................... 40 Flax......................34 Colocynth.................... 16 Poppy.....................40-50 Cherry.......................... 42. Sesame.................................................... 40 Mstard, while............................................... 16 black................... 29 Buckthorn........................ 16 Hemp..................... 28 Currant......................... 26 Peanut.......................... 88 Beechnut........................ B4 3-.0 - t 100 100 100 100 100 100 100 100 100 100 100 .100 100 100 100 100 100 100 9.1 9.3 9.4 9.7 11.0 12.1 12.2 13.0 13.3 14.3 14.6 15.3 16.5 16.6 16.9 18.5 18.6 22.8 6.9 6.5 5.2 0.9 6.6 16.9 8.6 1.5 2.1 5.5 2'1 3.2 1.3 1.5 3.6 1.2 1.5 5.8 I t li,T CR OPS FEED. A TREATISE ON THE ATMOSPHERE AND THE SOIL AS RELATED TO THE NUTRITION OF AGRICULTURAL PLANTS. BY SAMUEL W. JOIIHNSON, A.A., PROFESSOR OF ANALYTICAL AND AGRICULTURAL CIHEMISTRY IN THE SHEF FIELD SCIENTIFIC SCHOOL OF YALE COLLEGE; CHEMIST TO THE CON NECTICUT STATE AGRICULTURAL SOCIETY; MEMBER OF THE NATIONAL ACADEMY OF SCIENCES. The work entitled "How Crops Grow" has been received with very grent favor, not only in America, but in Europe. The Author, therefore, puts forth this volume-the companion and complement to the former-with the hope that it also will be welcomed by those who appreciate the scientific aspects of Agriculture, and are persuaded that a true Theory is the surest guide to a successful Practice. Ill this, as in the preceding volume, the Aulthor's method has been to bring forth all accessible facts, to present their evidence on the topics under discussion, and dispassionately to record their verdict. If this procedure be sometimes tedious, it is always safe, and there is no other mode of treating a subject which can satisfy the earnest inquirer. It is, then, to all Students of Agriculture, whether on the Farm or in the School, that this volume is specially commended. CONTENTS. DIVISION I. Tile Atmnosphere as Related to Yegetatioin. CHAPTER I.-ATMOSPHERIC AIR AS FOOD OF PLANTS. CHAPTER II.-THE ATMOSPHERE AS PHYSICALLY RELATED TO VEGETATION. DIVISION II. The Soil as Related to Vegetable Production. CHAPTER I.-INTRODUCTORY. CHAPTER II.-ORIGIN AND FORMATION OF SOILS. CHAPTER III.-KINDS OF SOILS, THEIR DEFINITION AND CLASSIFICATION. CHAPTER IV.-PHYSICAL CHARACTERS OF THE SOIL. CHAPTER V.-THE SOIL AS A SOURCE OF FOOD TO CROPS: INGREDIENTS WHOSE ELEMENTS ARE OF ATMOSPHERIC ORIGIN. CHAPTER VI.-THE SOIL AS A SOURCE OF FOOD TO CROPS INGREDIENTS WHOSE ELEMENTS ARE DERIVED FROM ROCKS. Price, post-paid, $2. ORANGE JUDD & COMPANY, 245 Broadway, New- York. Bvith Illustrationis. FARM IPLBEMNTB AND MACHINERY, AND I Principles of their Construction and Use: SIMPLE AND PRAOTIOAL EXPLANATIONS OP TI LAWS OF MOTION AND FORCE, AS APPLIED ON THE FARM. Withl 287 Illustrations. By JOHIN J. THOMAS. CONTENTS. PART,I.-MECHA ICS. CI[APTER I.-INTRODUCTION.-Value of Farm Machinery-Importance of a Enowledge of Mechanical Principles. CAPTER II.-General Principles of Mechanics. CHA,PTER III.-Attraction. CHAPTER IV.-Simple Machines, or Mechanical Powers. CPTER V.-Application of Mechanical Principles in the Structure of I' plements and Machines. CHAPTER VI. Friction. CHAPTER VII.-Principles of Draught. CHAPTER VIII.-Application of Labor. CHIAPTE IX.-Models of Machines. CHAPTER X.-Construction and Use of Farm Implements and Machine_ Implements of Tillage, Pulverizers. CHANTER XI.-Sowing Machines. CHAPTEER XII.-Machlies for Haying and Harvesting. CaOPTER XIIL-Thrashing, Grinding, and Preparing Products. PART II.-MACHINERY IN CONNECTION WITH WATER. CHAPTER I.-Hydrostatics. CaTER 11.-Hydraulics. PART m.-MACHIN ERY IN CONNECTION WITH AIR. CHATTER I.-Pressure of Air. CHAPTEB II.-Motion of Air. PART IV.-IIBEAT. CAPTER I.-Conducting Power-Expansion, Great Force of-Experimenu with-Steam Engine-do. for Farms-Steam Plows-Latent Heat Green and Dry Wood. oII.-Radiation. APPENDIX. Apparatus for Experiments. Diseoar-e of Water through Pipes. Velocity of Water in Pipes. Rule for Discharge of Water. Velocity of Water in Tile Drains. Glossary. Price, Post.paid, $1.50. ORANCE JUDD & CO., 21i. Broadway, New-York, WITH i7