\\ mec aatrenrt tesa New ES SNAT SS Ta ae biol PR Ww Gibson. WR SeLib Lon g Fo al Ww ” oo o HOW CROPS GROW. A TREATISE ON THE CHEMICAL COMPOSITION, STRUCTURE AND LIFE OF THE PLANT, FOR ALL STUDENTS OF AGRICULTURE. WITH NUMEROUS ILLUSTRATIONS AND TABLES OF ANALYSES. BY SAMUEL W. JOHNSON, M. A. PROFESSOR OF ANALYTICAL AND AGRICULTURAL CHEMISTRY IN THE SEPFFIBLD SOIENTIFIO SCHOOL OF YALE COLLEGE; OHEMIS’ TO THE OCNNEG TIOUT STATE AGRICULTURAL SOCIETY; MEMBER OF THE NATIONAL AOADEMY OF SCIENCES, CIBER ART aw YORE BOTANICAL ratwetirRen NEW YORK: 0. JUDD CO., DAVID W. JUDD, Przs’r, 751 BROADWAY. 1888, Entered according to Act of Congress, in the year 1868, by ORANGE JUDD & CO., &t the Clerk’s Office of the District Court of the Unitid States for the Southern District of New-York, LovgEsJoy, Son & Co., Execrrotyrers & STEREOTYPERS, 15 Vandewater Street, N. Y. 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 Agriculture, and is offered to the public in the hope that it wili supply a deficiency that has long existed in English literatvre. The pregress of these branches of science during recent years has been very great. Thanks to the activity of numerous English, French, and especially German inves- tigators, 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 ') markable advances, has disencumbered itself of many * useless 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 Iv HOW CROPS GROW. subject of vegetable nutrition, and to estimate accurately how and to what extent the crop depends upon the at- mosphere 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, ad 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 him- self of their validity and importance. In many cases ful- ness 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 ar- rived at, is a necessary part of the education of those who are hereafter to be of service in the advancement of agri- culture. The Agricultural Schools that are coming into operation should do more than instruct in the general re- sults of Agricultural Science. They should teach the subject so thoroughly that the learner may comprehend at once the deficiencies and the possibilities of our knowl- edge. Thus we may hope that a company of capable in- vestigators may be raised up, from whose efforts the science and the art may receive new and continual im- pulses. 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 informa- tion 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, consid- ered 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 ——— eS oe ee PREFACE, Vv of his acquaintance with them. Such facts are not, how- ever, 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 nseless 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 suck 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 di- vision of the matter into convenient paragraphs. To aid the student who has access to a chemical labor- atory 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 impres- sions of study. The author has endeavored to make this volume com- plete in itself, and for that purpose has introduced a short section on The Food of the Plant. In the succeeding vol- ume, which is nearly ready for the printer, to be entitled “How 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 VI 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 be- ing a middle man and not a producer of the priceless com- modities 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 Agricul- tural Science, now white with a harvest for which the reapers are all too few, 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. : ScHLEIDEN.—Fig’s 10, 13, 17, 19, 30, 48, 49, and 50, Physiologie der Pflanzen und Thiere. Sacus.—Fig’s 56 and 65, Sitzungsberichte der Wiener Akademie, XX XVII, 1859, and fig’s 22, 38, 40, 41, 42, 43, 59, 66, 69, 70, and 71, Haperimental-Physiologie der Pflanzen. Payen.—Fig’s 11, 12, and 23, Precis de Chimie Indus. trielle. Ducuartre.—Fig’s 60 and 61, Eléments de Botanique. Ktun. — Fig’s 18, 21a, 29, and 34, Hrndhrung des Rindwiehes. Hartie.—Fig’s 20, 21b, 32, Hntwickelungsgeschichte des Pflanzenkeims. Unerr.—Fig. 26, Sitzungsberichte der Wiener Akade- mie XLIII, and fig. 55, Anat. u. Phys. der Pflanzen. Scuacut.—Fio’s 33, 37, 44, Anatomie der Gewachse, fio’s 51, 53, 54, and 62, Der Bawm, and fig’s 52, 57, ana 58, Die Kartoffel und thre Krankheiten. Henrrey.—Fig’s 36 and 39, Jour. Roy. Ag. Soc. of England, Vol. XTX, pp. 483 and 484. 7 TABLE OF CONTENTS. EMTRODUCTION:. 05.050 56-5 . alt Sei dee aceee aeeeene 28 § 2. Elements of the Volatile Part of Plants...................- 81 Carbon, Hydrogen, Oxygen, Nitrogen, Sulphur, Phosphor- us, Ultimate Composition of Organic Matter......... creme 8. Chemical Adgfnity wr. .-ccc terie Wo ass Cole onic Callens eee 46 4. Vegetable Organic Compounds or Proximate Elements....... 52 Le Water. 5 cis:0:c oc hs!s.01c wie c s)eiareie vein le etalon si tare aetna emcee > 2. gathilosd GrOUDsidisccicisdoutnrec ecto o vicia\ove bra ietwistaterenaraie 65 8. Pectose Pr [tacichtersehee ae altace din, inte a ae catatintate dcomwente 81 4. Vegetable ACidS:. 3.5: «cio0 cae. seis sisdeels sees va eines 85 ys WHat, Fa) Kicks aisistsie wistate wis oes stpinnelee tele ee ttetsiate = slve easement 6: Albuminoids: 2.3. -stsewets a wccheiteeee oe eh aaee ane Appendix, Chlorophyll, etc............ ROC EAL: 109 Guar: Il.—Tar AsHor PLANnta:... i .i...cenes saa ste euns dete Pee eerie ccc Lei! § 1. Ingredients of the Ash... ©... ..%)....-ccecveleciee oaevieeiasivislohibrarmaeaun Non-metallic Elements... .............c0ee-eeeee oes enlenjeeeeiain Carbon and its Compounds ne weitaae eseaee vison ve Seem eens Sulphur Sen bee wee csee c/s qa umqeat Ren Phosphorus ‘** ‘* Ser La Wactaetee wate ciate atate aio's cle sivlow sitesesannn Silicon SENN ASE ~ aeanicislecniaeniee os\c\e\e sin alemieateepeeeg Metallic Elements....................cceseeeeee ao sic eis atatd d cle sieieleeetnae Potassium and its Compounds BAO doscce a nlaiewiefenuale anne 124 Sodium BE EER Sh RCE SN) Ce secre Sree aetna edeatile eee Bees te. ! Calcium een ee I eR COS: ain (a'njmrd| a /eintale eee oat 15 Magnesium and its Compounds siete 04 0 d:c'e'e,eiele.aialereeteaear arate 126 Iron ane clainlaninlatatenatate anteiobiaatstettats 127 Manganese Salevia wie RU Ga Siac 5 chet via eases cisiwiviaiore enaiaiselaasiciee Carbonates.. SUPP ates. ot. \o< prog sini! stalare) eyelniaie/aio aiatololelaieisteletttaetae Phosphates 011 (0 (6 {1 ARG en eInE ESO CRIS ICOR SOCDDOA OCI: 22 or eniah wearers 135 INT HATO 6s Scere cic a b.als’s eieceie ova ba.a nictera close ete alee jeenlete 136 § 2. Quantity, Distribution, and Variations of the Ash. 3 jceee - 138 able of Proportions of Ash in V egetable Matter............ 139 § 8. Special Composition of the Ash of ‘Agr icultural Plants....... 147 1. Constant Ingredients... . 2% 00.26. cas0cncewslteenen ana 148 2. Uniform composition of normal specim’s of given plant. is Table of Ash-analyses........:0-sss0% saiuinecsialee mata 8. Composition of Different parts of Plant.......... IBY 4. Like composition of similar plants..............+0. ..159 5. Variability of ash of same species............ .+-se0es 180 6. What is normal composition of the ash of a plant?..... 163 % To what extent is each ash-ingredient essential or acci- Cental sac. <:cictentere:vioielealateivieleve s/a!eisial ejeteoraaae e-aveiere psa Seva Water-cultnre. vi... 2 aiccisscaisjetctelseraacneete on, a's ils pie aaa 167 Essential ash-ingredients. . nitiee 172 Is Soda Essential to Agricultural | Plants? ....+s:cepnuen 172 Oxide of Iron indispensable..........00.0ss+300 seas Oxide of Manganese unessentibl.......e:ceccceececee- 10D Is chlorine indispensable ?..........eeeeeeeeeee ha wate ewetataes Silica is.not.essential.;...05 alee celeoeniaere Cua>, IL.— §1. Food of the Plant when independent of the Seed............ 327 §z. The Juices of the Plant. Their Nature and Movements.... 330 GOV LOM SAD senses oe leicle ccaremnts oe cle ticinle-a.e-e Risie in oalsteitreloig step iaters 331 BlCeding. .. 0.2... esse ween ccc ee cons cescscerccccccesccnscecens 332 MOM OSiAOM OL Sapscs, cacti alte Sec class elstore'd olalotatctatoral etme 337 PRG FOENS AP watts =. sataty a pepe kis cine cleteleninve aiutu/aid a/oftla lelwatavalamieeteior 333 Motroniof Nutrient Matters: visi yet aicts cleiaia’ = win/etS niet 125 Be MINN CHON Olesen cieisaibiere 197 = SS. NECTAR S eso nin alata oleieiae 125 PAL MOLAIS a aise \a\eieialo eleinielvle tietsl tas Pre s 380 Barley, Ash-analyses..150, 153, 160, 878 Proximate analyses... 387 detailed. oat ee Lay ‘© Root-cap Ofm.s. saccesessnee “6. -Root-hairs.Of.:4., esicumtmetes i 2a Barley-Sugar.c...2cs-sls ssues couse 43 Baryta in plants....... eeaideloutewene 196 Bases, Definition of. . MPP eye) BASSOLIN.. »\ 00 aeieeaierels ee BTUCLOSC «i5,6)0,0 20s aciesacteet casa denial aenes Fruit. -.:.s0d%. Scenes aclneeene Fruits, Ash Pr NE 379 “© Composition of,....ssseneeen 390 Bruit Sugar........ daasisenc ce ctstepaeres 58 Light seeds, Plants from........... 307 Nitrogen, Properties of............ 3T Lignin ona. ceguOBAe donovan dcboren ak ID ASHG corer an seat veeelibe BRAPIEM aeeaia Sse cc alsisccelciseeses 126 aC Germination... css 32d “* essential to vegetation ....... 172 & relation to phospharier MAE ELOLS. cos occ sec veueesee. 36, 126 MCI a. su cose neclore een ) Pressic VAciC......00s0. saacomeeln ane 114 PoP Dals. ca... sacle: .simmtaia cacao ee 232 Pulp of fruits... .....sesnssasemmee eee 223 Quack rags. ..... «s00.000biesimaineoens 266 Quantitative relations —— ingre- dients of plant. eos dtaswle.e said GNIALI 7s « chysiperaiae 2 ating ra Quercitannic acid....... .... ee | INDEX. xv oe By sisareysts svewctebeceses oo 18 , Saponification... -... Di Saneelefa oo. 28 Rabe sais fais tai \aixta'o 0 «lero ste'e.oy'e'e _.308 | Saussure, exp. 01 mint......... .-. 1387 Red clover hay, Ultimate analysis of. 45 SAXEFVAGG CTUSLALLs.. ee ees vere oes 192 “ beet, Pigment of........-+.+5+- 367 | Scotch fir, Wood-cells of, fig.... .. 209 “ pine, Pith rays Of.......---.++- 276 | Scouring rush.......++-+..+s++08 +: 184 BER ETADISV Ard charac: ciats'e «(n\n nis) s\0/0,jle's's) (o'e'e 223 | Screw pine, Root cap of, fig..... .- 236 Relations of Cellulose and Pec ose Sea-weeds, Potash in.. 198 BATELEIE Senne oe a) « wise (cinin = lsiete @'ele Seed . 52. c wotetereiansersterm oe i Relations of Fats to Amyloids..... 94 We“ VESSElocc,- = clarmccteieiorcletureictelers Oe “ Veg. Acids to Amy- Seeds, constancy of composition. ..145 EEG Serta a ie ciciersrcin\s\c sisisielviaiaeis ole 89 | Selecting power of plant Reproductive Organs........... 922, 291 | Sepals... 2.0... cece ecer cere rene cess Rice, ash-analysis.......... 151, 152, 379 | Series.......-...-2.- see ee seen er eee 298 EMILORS fa vleraeicloreislow ewe aioe 387 | Sesquioxide of iron........+++-+-+- 128 43 PT © detailed ..........389 ee ‘+ manganese......... 128 BEREROES) Ole ser = = 00 cicics os cceecie- 952 | Sieve-cells ......-.... escsees-eees 280 SEMIN Ae cieinic)otnin oja'0e en aie'we Srctateraratelore 15 Be Corie aU EA Souconcoe 3438, 345 Ringing of stems... ......+.+++++- 944) 7| Silex... 35). iS ares) JaistGaisals shia) dia's 120 Rock Crystal.......---+++++ Sey AO. §|) SHC a ec. < ae xs 0'e 01s wrote wioletersawtnaiadtelenceale 120 Root-action, imitated............-- 361 * does not prevent lodging of a ee in winter............-.d00 PTAIN..... 2.0.02 cree en se eens ones 98 o3 ee MSTIOSE. Ure rciers vine aiele'e 360 ‘* Function of, in plant....... tL ON MTNA Rte ay acc a5 Sic, 0 a’ GereiSie\eie!seieieje 5 BET AGH: cc, marciacfnnis'stolerm ala mtstepmtaters 183 * crops, ash-analyses Cen Oe: Oat. amc ctnvetaicisehynioinle ote jet 98 Wy SE DEOX., (°° ase se 6 ¢ textile materials...........- 185 PE CHAD ES. - <2 « $)0 01012 sie e'slvcins ‘¢ unessential to plants.........- 183 * distinguished from stem...... 996 | SIICALES. .. ...<2 87 Saltwort...... Petal MuIieIe bysidis cleis's vfelee'e 177 BGP MTG nsecicaan seco seren's Trommer’s test for........: 75 Sulphate of line. -. 2s. ss. Secs tes 133 aS SoM NOkAS nee seco neclanciecias 132 3 PP BOUMS c cas ccsaeeenc 132 PM Hates Fsas Sonnet oalcierere 43, 117, 132 SS Muncttion Of, 2s oac.c cde sje 196 of STUCGLONCE ++ can siasarcsrss ices = 194 a reduced by plane: adariescode 190 Sulphides.. Ste asda oo Le Sulphide of potassium.. Seamtelsleetoaiesiel= 115 Sulphites Lphdadantaoonacohonoocpoale 115 Sulphocyanide of allyle............ 114 Saiphurtc jsjehss sv asecascese «2 42, 114 Phe WEOORLS Paticens = bebe sisan 9 cess 194 Sulphureted hydrogen........... 43, 115 SUIPMULC tasers sesaces cess seen 42 Su)phuric ers eg oecerinapone .. 42, 116 “ MMI OAL 3 Falcone ree 219 SHIPHNTONS ACC... -ccscocccssecs 42, 115 PUIphyaric acid. sa. swesacexisoes 43, 115 Supercarbonate of soda............ 131 Superphosphate of lime............ 135 Symbols, Chemical........cccsee-ce 47 RIED MUTE ae eos Aaisictatatesicicie Seisiereloisiete PEANUTS Gi eile veseis ive sccm haces AD TOOs cee e) eece wee SRADIOCR sa. donc vane Tap-roots Partaric Acid. \..5%. hanum, copper, zinc, and titanium. 32 HOW CROPS GROW. Expr. 2.—If a splinter of dry pire wood be set on fire and the 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- bustion. Exp. 3.—Hold a knife-blade in the flame of a tallow candle; the full access of air is thus prevented,—a portion of carbon escapes combustion, and is deposited on the blade in the form 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 char- coal, or bone-black. . Lignite, bituminous 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 illuminate ing 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 de- gree 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 THE VOLATILE PART OF PLANTS. 3a 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 ex- clusive result of vital organization, no ingredient of the animal or vegetable produced by their growth, that docs 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 atmos- phere 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 slow.y converted into a red powder (red precipitate or oxide of mercury), which on being more strongly heated is decom- posed, 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- ok 34 HOW 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 14 inch wide, con- tains the oxide of mercury or chlorate of potash.* To its mouth is con- nected, 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 saucer-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 pot- ash 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 delivery-tube from 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 ren- ders the heat of a common spirit lamp sufficicnt. THE VOLATILE PART OF PLANTS. 393 As this gas makes no peculiar impressions on the senses, we employ its behavior towards other bodies for its recog- nition. Exp. 5.—Place a burning splinter of wood in a vessel of oxygen (lift- ed for that purpose, mouth upward, from the water). The flame 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 tha oxygen. It is instantly relighted. The experiment mav 4e repeated many times. This is the usual ¢est for oxygen gas. Combustion.—-When the chemical union of two bodies takes place with such energy as to produce visible phe- nomena 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 at- mosphere 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 vigor- ous combustion, whether it be done by a bellows or re- sult from ordinary draught. Oxygen exists in our atmosphere to the extent of about one-fifth of the bulk of the latter. Whena 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 in- different in its chemical affinities toward most bodies. In the air a piece of burning charcoal soon gces out; but if plunged into oxygen, it burns with great rapidity and brilliancy. Exp. 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 of oxygen, 36 HOW CROPS GROW. fig. 3. When the combustion has declined, a suitable test applied to the air of the bottle will demonstrate that another invisible gas has taken the place of the oxygen. Such a test is lime-water.* On pouring some of this into the bottle and agitating vigorously, the previously clear liquid becomes milky, and on standing, a white deposit, or precipitate, as the chemist terms it, gathers at the bottom of the vessel. Carbon, by thus uniting to oxygen, yields carbonic acid gas, Which in its turn combines with lime, producing carbonate of lime. These substances will be further noticed in a subsequent chapter. Metallic iron is incombustible in the at- mosphere under ordinary circumstances, but if heated to redness and brought into pure oxygen gas, it burns as readily as wood burns in the air. Exp. 7.—Proyide a thin knitting needle, heat one end red hot, and sharpen it by means of a file. Thrust the point thus made into asplinter of wood, (a bit of the stick ofa match, 14 inch long;) pass the other end of the needle through a wide, flat cork for a support, sect 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 into oxide of iron, a part of which will be found as a’ 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. The only essential difference between these and ordinary cases of combustion is the intensity with which the pro- cess 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 rusés, 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 fora 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. THE VOLATILE PART OF PLANTS. on matters at common temperatures is strictly analogous in a chemical sense to actual burning, Liebig has proposed the term eremacausis, (slow burning), to designate the chemi- cal 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 breath- ing introduces it into the lungs and blood of animals, where it aids the important office of respiration. Ani- mals, and plants as well, speedily perish if deprived of free 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 sev- eral distinct oaides, of which iron-rust is one, and anvil- scales another. In decay, putrefaction, fermentation, and respiration, numberless new products are formed, the re- sults 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 solil 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 expe- rience 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 impor- tant uses, as will presently be seen. For the preparation of nitrogen we have only to remove the oxygen from a portion of atmospheric air. This mav 38 HOW CROPS GROW. be accomplished more or less perfectly by a variety of methods. We have just learned that the process of burn- ing 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 ordi- nary 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 ecapacious glass bottle or bell jar. The phosphorus burns at first with a vivid light, which is presently ob- secured by a cloud of snow-like phosphoric acid. The combustion goes on, however, until nearly all the oxygen is remaved 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 yolume Fic. 5 as its oxygen is removed, so that it is needful to pour BONG, water on the plate to prevent the 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 fol- lowing: A handful of copperas (sulphate of protoxide of iron) is dis- solved 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 stopper- ed, 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 scarce- ly any active properties, but is best characterized by its chemical indifference to most other bodies. That it is in- capable 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. THE VOLATILE PART OF PLANTS. 39 Nitrogen cannot maintain respiration, so that animals perish if confined in it. For this reason it was formerly ealled Azote (against life). Decay does not proceed in an atmosphere of this gas, and in general it is difficult to ef- fect its direct union with other bodies. At a high tem- perature, especially in presence of baryta, it unites with carbon, forming eyanogen—a compound existing in Prus- sian-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 asmall 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 con- sidered, 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 emana- tions 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 hy- drogen, and therefore leave it uncombined. Sodium, a metal familiar to the chemist, has such an at- traction for oxygen that it decomposes water with great rapidity. Exp. 11.—Hydrogen is therefore readily procured by inverting a bot- tle full of water in a bowl, and inserting into it a bit of sodium as large asapea,. Thesodium 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. Metilic iron and zine decompose water, uniting with 40 HOW 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 zine 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 cork, funnel, and delivery tubes, fig. 6, an ounce of iron tacks or zine clippings is introduced, a gill of water is poured upon them, and lastly an ounce of oil of vitriol isadded. A brisk effervescence shortly com- mences, 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 rejected, as the mixture is dangerously explosive. One of the most strik- ing properties of free 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 lighted taper, and burns with a flame which is intensely hot, though searee- ly luminous if the gas be pure. Final- 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 THE VOLATILE PART OF PLANTS. 41 brought to its mouth. At first a slight explosion is heard from the sudden burning of a mixtureof the gas with air that forms at the mouth of the vessel; then the gas is seen burming on its lower surface with a pale flame. If now the taper be passed into the bottle it will be extinguished; on low- ering it again, it will be relighted by the burning gas; finally, if the bot- tle be suddenly turned mouth upwards, the light hydrogen rises ina 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 universally dif fused compound, water. The conditions of the experiment do not permit the collection or identification of this wa- ter; its production can, however, readily be demon- strated. Exp. 14.—The arrangement shown in fig. 8 may be employed to ex- hibit the formation of water by the burning of hydrogen. Hydrogen gas is generated from zine 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 from the apparatus, the gas is ignited at the up- curved 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 occur- ring in much quantity, save as water. It is a constant in- gredient of plants and animals, and of nearly all the numberless substances which are products of organic life. #2 HOW CROPS GROW. Hydrogen forms with carbon a large number of com. pounds, the most common of which are the volatile oils, like oil of turpentine, oil of lemon, ete. The chief illumi- nating ingredient of coal-gas (ethylene or olefiant gas,) the coal or rock oils, (kerosene,) together with benzine and paraftine, 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 voleanic ori- gin; 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 sulphurous 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, eymbustion, and the development of sulphurous acid. Further, scoop out alittle hollow in a piece of chalk, 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 acid. ‘ Sulphur forms with oxygen another compound, which, in combination with water, constitutes common sulphuric acid, or oil of vitriol. This is developed to a slight ex- tent by the action of air on flowers of sulphur, but is pre pared on a large scale for commerce by a complicated process. Sulphur unites with most of the metals, yielding com- 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. a a a rs THE VOLATILE PART OF PLANTS. 4d Sulphides may be formed artificially by heating most of the metals with sulphur. Exp. 16.—Heat 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-spring made into 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, bwns in the sulphur gas, giv- ing rise to a black sulphide of iron, in the same manner as in Exp. 7 it purned in oxyyen gas 1nd 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 ina 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 sulphurie acid. Exp. 17.—Place a lump of the sulphide of iron prepared in Exp. 16 in & cup or wine-glass, add a little water, and lastly a few drops of oil of vitriol Bubbles of sulphuretted hydrogen 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, horse- radish, 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 44 HOW CROPS 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 occur- ring 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, de- rived from two Greek words signifying light-bearer. The other form is brick red, opaque, far less inflammable, and destitute of poisonous properties. Phosphorus is exten- sively employed for the manufacture of friction matches. For this purpose yellow phosphorus is chiefly used. When exposed sufliciently long to the air, or immedi- ately, on burning, this element unites with oxygen, form- ing a body of the utmost agricultural importance, viz.. phosphoric acid. Exp. 18.—Burn a bit of phosphorus under a bottle as in Exp. 8, omit- ting 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 wa- ter. 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 phos- phorie 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 phos- phate of lime. It is from them that the phosphorus em- ployed for matches is largely procured. Exp. 19.—Burn a piece of bone ina fire tntil 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 so lutions of various metals with solution of phosphoric acid. Exp. 20.—Pour into each of two wine or test glasses a small quantity THE VOLATILE PART OF PLANTS. 45 of the solution of phosphoric acid obtained in Exp. 18. To one, add some lime-water (see note p. 36) until a white cloud or precipitate is per- ceived. This isa phosph_te of lime. Into the other portion, drop solu- tionofalum. A translucent cloud of phosphate of aluminais immediately produced. In soils and rocks, phosphorus exists in the state of such phosphates of lime, alumina, and iron. In the organic world tue chemist has 28 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 ot 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 char- acters of those six bodies which constitute that part of plants, and of animals also, which is volatile or destruct- ible 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. Grainof Strawof Tubersof Grain of Hay of Red Wheat. Wheat. Potato. Peas. Clover. BEPODON Ge scale sceeesae 46.1 48.4 44.0 46.5 47.4 HAVEN scccccscescccs 88 5.3 5.8 6.2 5.0 MERCI salt sive. sive es'e.0 43.4 38.9 44.7 40.0 37.8 INUEEGS CR cuisine ss 220s 000s 2.38 0.4 1.5 4.2 2.1 Ee ing sul ie see PPE deccccvccessss 0,12 0.14 0.08 0.21 0.18 Phosphorus............. 0.30 0.80 0.34 0.34 0.20 46 HOW CROPS GROW. Our attention may now be directed to the study of savk 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 de gree of interest. Previous to this, however, we must, first of all, gam a lear 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 ¢s the force which unites or combines two or more substances of unlike character, to a new body different from its ingredients. Chemical combination differs essentially from mere mix- ture. 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 chemi- cal combination, they are capable of yielding a series of no jess 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. THE VOLATILE PART OF PLANTS. 4? Chemical decomposition.—Water, thus composed or put together by the exercise of affinity, is easily decom- posed or taken to pieces, so to speak, by forces that op- pose 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 propor- tions, which are fixed and invariable. Oxygen and hydro- gen, 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 indi- visible 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 weigh? are always to bo anderstood. 48 HOW CROPS GROW TABLE OF ATOMIC WEIGHTS AND SYMBOLS OF ELEMENTS.® 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 Cl Mercury 200 Hg (Hydrargyrum) Potassium 39 K (Kalium) Sodium 23 Na (Natrium) Calcium 40 Ca Tron 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, con- sisting of one atom of each ingredient, and carbonic acid, which contains to one atom, or 12 parts by weight, of car- bon, 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@ com- pound body, but this is an absurdity, for the smallest par- ticles of compounds admit of separation into their elements. The term molecule implies capacity for division just as atom excludes that idea. * Latterly, chemists are mostly inclined toreceiveas the true atomic weights double the numbers that have been commonly employed, hydrogen, chlorine and ¢ few others excepted. + Latin diminutive, signifying a little mass, THE VOLATILE PART OF PLANTS. 49 The molecular weight of a compound is the sum of the weights of the atoms that compose it. For example, wa- ter 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 compo- sition of a somewhat complex compound, one of the car- bonates of ammonia. Ammonia gas results from the union of an atom of nitrogen with three atoms of hydrogen. One molecule of ammonia gas unites with a molecule of carbonic acid gas and a molecule of water, to produce a molecule of carbonate of ammonia. oe ee eee = tat? parts Carbonate Garnonie acid | Carbon, hte aaa eee mol. = Oxygen, 2 “ = go {=H parts; —70 parts, Water, a I ele aa . 4g }=18 parts 1mol. ~{ Oxygen, 1“ =16/— °° P Notation of Compounds,—For the purpose of express- ing easily and concisely the composition of compounds, and the chemical changes they undergo, chemists have agreed to make the symbol of an element signit'y one atom of that element. Thus H implies not only the light, combustible gas hy- drogen, 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 O, oxide of mercury by Hg O, and sulphide of iron by Fe S. C O 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, - 50 HOW CROPS GROW. When a compound contains more than one atom ot aa 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 H,O. In like manner the symbol of carbonic acid is C O,,. 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 H, O. The symbol of a compound is usually termed a formula. Subjoined is a table of the formulas of some of the com- pounds that have been already described or employed. FORMULAS OF COMPOUNDS. Name. Formula, Molecular weight. Water H, O 18 Sulphydric acid H,S 34 Sulphide of iron FeS 88 Oxide of Mercury Hg O 216 Carbonic acid (anhydrous) CO, 44 Chloride of calcium Ca Cl, 111 Sulphurous acid (anhydrous) SO, 64 Sulphuric acid 58:0; 80 Phosphoric acid PO: 142 Impirical and Rational Formulas,—It is obvious that many different formulas can be made for a body of com- plex character. Thus, the carbonate of ammonia, whose composition has already been stated, (p. 49,) and which contains 1 atom of Nitrogen, gt ee @aron: 3 atoms “ Oxygen, and 5 © Bydrogen. may be most compactly expressed ky the symbol N C:O.H, THE VOLATILE PART OF PLANTS. 51 Such a formula merely informs us what elements and how many atoms of each element enter into the composi- tion of the substance. It is an emgirical formula, being the simplest expression of the facts obtained by analysis of the substance. Rational formulas, on the other hand, are intended ty 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 Nei. OFC O.. 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 following statement. Chlorate of potash. Chloride of potassium. Oxygen. K Cl O, = K Cl ve O, The sign of equality, —, shows that what is written be- fore 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 exhibit- ing 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, pc. or ’|,.) These modes of expressing com. position are very useful for comparing together different compounds of the same elements, and, while usually the atomic statement answers for substances which are coin- paratively simple in their composition, the statement per cent is more useful for complex bodies. The composition 62 HOW CROPS GROW.. of the two compounds of carbon with oxygen is given be low according to both methods. atomic. Per cent. Atomic. Per cent Carbon, (C,) 12 42.86 (C) 12 27.27 Oxygen, ©, 16 57.14 (Ox) 82 72.93 Carbonic oxiie,(C O,) 28 100.00 Carbonic acid, (C Os,) 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 compositior of water from its atomic formula. Water, H, O, 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.: H, O Water H Hydrogen 1k een 100 rae ain Rus per cent sought ( = 11.11+) H, O Water O Oxygen 1S eran 100 2c 16: percent sought ( = 88.88+) By multiplying together the second and third terms of these propor- tions, 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 struc- ture, and which are produced from the elements carbon, oxygen, hydrogen, nitrogen, sulphur, and phosphorus, by the united agency of chemical and vital forces. The num- ber of distinct substances found in plants is practically un- limited. There are already well known to chemists hun- dreds of oils, acids, bitter principles, resins, coloring mat: ters, etc. Almost every plant contains some organic body THE VOLATILE PART OF PLANTS. 53 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 proper. ties, micotin, 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 occur- ing in the vegetable kingdom, it is a few which form the bulk of all plants, and especially of those which have an agri- cultural 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 de- tail under six principal groups, viz: 1, WarTER. 2. The CrrtuLtosze Group or Amytorps—Cellulose, (Wood,) Starch, the Sugars and Gums. 3. The Pecrosr Grour—the Pulp and Jellies of Fruits and certain Roots. 4, The VecETABLE Acips. 5. The Fats and Ors. 6. The ALBumivor or Proter Boptes. 1. Water, H, O, 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 the fresh state, but the pro 54 HOW CROPS GROW. portions are not quite constant, even in the same part of different speci- mens of any given plant. WATER (per cent) IN FRESH PLANTS. Mendow gTass...25 02245. 2. os ae denials ae ee 72 mediclover.2.. « wou oe a ale /erebeie 01a 'a ie’ ciate o\ef oe 79 Maize, as used’ for fodder. ....2...2.6.-s0ce seen 81 ACAD DEL Ceo 05 cine. c:Fn'b «oie 0,2 500 0 0i5:015, sole 4 2 ae eee 90 IPOLALONTHDELS ...2 oi. . cara s es tes eo niaieion se sae 75 UGA DOCS iwi. b Fale nieces boc duans ceo ee eee 82 CALLOUS). «oie 5 o0stae's be Selegba ee wesc de aed a eee 85 TL TDTLLTOS, foie iccs, anes, 0; oro'srs10.0,9in1 86, sia/eles jaa eae chee ae ie 91 PING AVOOG 5... s/s 210) cracisadaaieanicciees . ano ee ean 40 In living plants, water is usually perceptible to the eye or feel, as sap. But it is not only fresh plants that con- tain water. When grass is made into hay, the water is by no means all dried out, but a considerable proportion re- mains 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, and will collect on the cold part of the tube. It is thus obvious that vegetable substances may con- tain water in two different 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 hay, the greater share of this water es- capes, so that the air-dry plant contains but about 17 per cent. On subjecting the air-dry clover to a temperature of 212° for some hours, the water is completely expelled, and the substance becomes really dry. Fig. 9. To drive off all water from vegetable matters, the chemist usually em- ploys 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, —re.™ THE VOLATILE PART OF PLANTS. 55 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-dry. WATER IN AIR-DRY PLANTS. MET ONve TARE (INE, iaPacs a5 a a/e1sislars/ scalars ole eke ae 18 TEA ia(Ly Cy Ob, KELDEl js... sac.< cs. a.0cie es so eimencieties 14 PUTA ZC MIGCTMIEL Se 5 5 gabe e:o:d7m%. fejeta's BS aes crepe Lands Sect reeeane 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, the free water of vegetation. ‘The water which remains in the air- dry plant is imperceptible to the senses while in the plant, —can only be discovered on expelling it by heat or other- wise,—and may be designated as the hygroscopic water of vegetation. The amount of water contained in either fresh or air- dry vegetable matter is constantly fluctuating with the temperature and the dryness of the atmosphere. 2. Tur CeLLtuLosEe Group, or THE AMyLOIDs. This group comprises Cellulose, Starch, Inulin, Deatrin, Gum, Cane sugar, Fruit sugar, and Grape sugar. These bodies, especially cellulose and starch, form by far the larger s':are—perhaps seven-eighths—of all the dry matter of vegetation, and most of them are distributed throughout all parts of plants. Cellulose, C,, H,, O,,—Every agricultural plant is an aggregate of microscopic cells, i. e., is made up of minute sacks or closed tubes, adhering to each cther. 56 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 see- tion at a, while at b an empty space is noticed. 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 tough- 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 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, >,) and white cloth and unsized paper made from these materials, are nearly pure cellulose. The fibers of cotton, hemp, and flax, are simply long and thick-walled cells, the appearance of which, when highly magnified, is shown ih fig. 11, where a represents the thinner, more soft, and collapsed cotton fiber, and % the thicker and more durable fiber of linen. THE VOLATILE PART OF PLANTS. 5? Wood, or woody fiber, consists of long and slender cells of various forms and dimensions, see p. 271,) which are deu- cate 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 sub- stances,) called lignin.* The hard shells of nuts and stone fruits conta'n a basis of cellulose, which is impreg- nated with ligneous matter. When quite pure, cellulose is a white, often silky or spongy, and translucent body, its appearance varying some- what according to the source whence it is obtained. In the air-dry state, it usually contains about 10°|, of hygro- scopic 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 dis- solving 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 nitrie acid. Schulze ascribes to it the composition CAN DON iotsicfeiasielelaie iets SRORROOLnCan Oe 55.2 AVALON clelapisicretaieinees se misielere sees 5.8 ARGV ECE. anes cnieis calsteioateieceeieleie sire’ 38.9 100.0 This rs, however, simply the inferred composition of what is left afver the cellulose, etc., have been removed. Lignin cannot be separated in tae pure state, and has never been analyzed. What is thus designated 1s probably a mix- ture of several distinct substances. Lignin appears to be indigestible by herbivorous animals, (G@rouven, V. Hof nister.) 3* 58 HOW CRUPS GROW. tion of caustic soda, and afterwards whitening the skeleton of fibers that remains by means of chloride of lime, (bleaching powder.) They are al- most pure cellulose. : Skeletons may also be prepared by steeping vegetable matters ina mix. ture of chlorate of potash and dilute nitric acid for a number of days. Exp. 22.—To 500 cubic centimeters,* (or one pint,) of nitrie acid of density 1.1, adi 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 temper- ature not above 65° F., until they are perfectly whitened, which may re- quire 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 em- ployed 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, botk 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- jline, gun cotton,) a body which burns explosively, and has been em- ployed as a substitute for gunpowder. Sulphuric acid ofacertain strength, by short contact with cellulose, con- verts 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 trestises and investigations. For small weights, the gram, abbreviated gm., (equal to 15% grains, nearly), is the customary unit. The unit of measure by voi- ume is the cubic centimeter, abbreviated c. c., (80 c. c. equal one fluid ounce nearly). Gram weights and glass measures graduated into cubic centimeters are farnished by all dealers in chemical apparatus. + Full-grown but not old leaves of the elm, maple, and maize, heads of un- ripe grain, slices of she stem and joints of maize, etc., may be employed to fur- nish skeletons that will prove valuable in the study of the structure of there organs. ~ THE VOLATILE PART OF PLANTS. 59 Exp. 23.—To prepare parchment ,uper, 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 liquidis perfectly cool, im- merse into it a strip of unsized paper, and let it remain for about 15 sec- onds; 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, va- rying 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 ¢es¢ for cellulose. Exp. 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 flowit witha weak solution of iodine,* when these dissolved portions will assume a fine and intense bluecolor. 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 cireum- stances, 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 chemi- 4 cal 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, ard therefore cellulose ranks among the nutritive substances. — ___ ® Dissolve a fragment of iodine as large as a wheat kernel in 20c. c. of alco- hol, add 100 c. c. of vrater to the solution, and preserve in a well stoppered bottle. + According to Grouven, cellulose prepared from rye straw, (and impure ?) requires several hours’ action of sulphtzic acid before it will strike a blue color with iodine, (2ter Salzminder Bericht, z 467.) i 60 HOW CROPS GROW. Chemical composition of cellulose-—This body is a com. pound of the three elements, carbon, oxygen, and hydro- gen. Analyses of it, as prepared from a multitude of sources, demonstrate that its composition is expressed by the formula, C,, H,, O,,. In 100 parts it contains Carbon, 44,44 Hydrogen, 6.17 Oxygen, 49.39 100.00 Modes of estimating cellulose—In statements of the composition of plants, the terms fiber, woody fiber, and crude cellulose, 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. Ifthe solvents are too concentrated, or the temperature at which they act is too high, cellulose itself is dissolved; while with toc 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 114 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. ec. 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 114 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 and nitro- gen, for which corrections must be made. The nitrogen is ass:med to belong to some albuminoid, and from its quantity the amount of the 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. Hofmeister, the crude cellulose thus prepared from the pea is perfectly white, that from wheat bran ia brown, and that from rape-cake is almost black in color. Grouven gives the following analyses of two samples of erude cellulose obtained by a method essentially the same as we haye described. (2fe Salzmiinder Bericht, p. 456.) THE VOLATILE PART OF PLANTS, 61 . Rye-straw fiber. Linen fiber VALET i ecreinaisie'ce 8.65 5.40 INNS so pesecsonce 2.05 1.14 ING .0.15 0.26 She SOS ABe eee 42.47 38.36 18 L Sppddeeaceoene 6.04 5.89 Ore estos eineiiciee 40.64 48.95 100.00 100.00 On deducting water and ash, and making proper correction for the nitrozen, the above samples, together with one of wheat-straw fiber, analyzed by Henneberg, exhibit the following composition, compared with pure cellulose. Rye-straw fiber. Linen fiber. Wheat-straw fiber. Pure cellulose. eeiscictsia’sis or 47.5 41.0 45.4 44.4 He miowice cisias''s 6.8 6.4 6.3 6.2 Bras tave/a\aia' 0:<\« 45.7 52.6 48.3 49.4 100.0 100.0 100.0 100.0 Franz Schulze, of Rostock, proposed in 1857 another method for esti- mating cellulose, which has recently, (1866,) been shown to be more coz- rect than the one already described. Kihn, Aronstein, and H. Schulze, (Henneberg’s Journal fiir Landwirthschaft, 1866, pp. 289 to 297,) have ap- plied this method in the following manner: One part of the dry pulver- -ized 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, (1¢ to 11g per cent,) is obtained. The results appear to vary but about one per cent from the truth. The average proportions of cellulose found in various vegetahle saatters in the usual or air-dry state, are as follows: 62 HOW CROPS GROW. AMOUNT OF CELLULOSE IN PLANTS. Per cent. Fer cent. Potato tubers. 22%. vse. 1.1 Red clover plant in flower...10 Wheat kernel. 2..6 se. 3.0 ae 6 Ray. sss aceon 34 Wiheatimedll occas soc 0.7 Timothy Wr pera sstmeets 23 MinizeMKarmMel’ss.<.c.e/cvsreisis » 5.5 Maize GODS. 505 -cee einen 38 BAIVOVT Mica sasmecee sa vaste 8.0 Oat StraW .cicoscceicativesiean 40 Oat Ce sc oateieatatere si 10.3 Wheat: ** | J ccc ccunince nee 48 Buckwheat kernel....... 15.0 Rye SS" wiciceiscceteiistee eee 54 Starch, C,, H,, O,,.—The 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 sim- ple. The potato contains, on the average, 76 per cent wa- ter, 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 starch- grains set at liberty. The pulp is then agitated on a fine sieve, in a stream of water. The washings run off milky, from 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 unalter- ed starch. Starch is now largely manufactured from maize. A ; A 4 | tients THE VOLATILE PART OF PLANTS. 63 dilute solution of caustic soda is used to dissolve the al- buminoids, see p. 95. The starch and bran remaining, are separated by diffusing both in water, when the bran rap- idly 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, horse- chestnuts, 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 repeat- edly 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 con- sists of minute, rounded grains, and hence has a slightly harsh feel. When observed under a powerful magnifier, these grains often present characteristic forms and dimen- sions. In potato-starch they are egg or kidney-shaped, and are distinctly marked with curved lines or ridges, which sur- round 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, 6. Oat-starch is made up of compound grains, which are easily crashed into smaller 64 HOW CROPS GROW. granules, c. In maize and rice the grains are usually so densely packed in the cells as to present an angular (six- sided) 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 at f, and those of the beet at g. The grains of potato-starch are among the largest, be- ing 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, (BSotanik 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 no- ticed by Schleiden. The starch-grains are unacted upon by cold water, un- less broken, (see Exp. 26,) and quickly settle from suspen- sion 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 near 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 ajelly. This is the starch-paste used by the laun- dress 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 Manihot, 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 islinds 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.—Tie 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. THE VOLATILE PART OF PLANTS. 65 Exp. 26.—Shake together ina test tube, 30c. 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 reflected light. On standing, observe thet in the first ease, where starch preponderates, it settles to the bottom leaying 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. ec. 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. ec. of water a little solution of iodine, and noting that a few drops of the solution of starch suffice to make the Jarge 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 germinat- ing seeds; see p. 328. The saliva of man and plant-eating animals usually likewise dissolves starch at blood heat by converting it in- to 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 im- portant ingredients of the food of man and domestic ani- mals. The action of saliva demonstrates that starch-grains are not homoge- neous, but cuntainasmall proportion of matter not readily soluble in this liquid. This remains as a delicate skeleton after the grains are other- wise 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. 66 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. Dragendorff. 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 ac- count in making any strict comparisons. AMOUNT OF STARCH IN PLANTS. Water Starch. Per cent Per cent AVA TICS aeteretainn cieteierterete tare 13.2 59.5 Wheat fours... cse0 20s 15.8 68.7 1M Olan dot Eaoeerenocnoce 11.0 59.7 Oa a prerayainteralss os cial ancte ae 11.9 46.6 IBATICY: cisierecies sieictsincioe © abs) 57.5 Timothy seed....... eens 12.6 45.0 Rice; Ciulled)f water as represented by the equation Starch, ce. Water Giucose. Cy2 Hoo Orin + 2H2O = Cig Hog Ore In this process, 90 paris of starch, &¢., yizid 190 parts of glucose. Trommer’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 re- duced to yellow or red suboxide. Exp. 31.—Prepare the copper test by dissolving together in 30 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 skin. Place in separate test tubes a few drops of solution of cane-sugar, »} Similar amount of the dextrin solution, obtained in Exp. 28; of solu- tio. of glucose, from raisins, or from Exp. 30; and of molasses; add to sach 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. + According to some authorities, the sugar of malt is distinct from glucose, and has been designated maltose. Provably, however, the so-called maltose is a mixture of glucose and dextrin. 76 HOW CROPS GROW. water. Observe that the saccharose and dextrin suffer no alteration for a long time, while the glucose and molasses shortly cause the separation of suboxide of copper. Exp. 32.—Heat to boiling a little white cane-sugar with 30c. e. of water, and 8 drops of strong sulphuric acid, in a glass or porcelain dish, for 15 ninutes, supplying the waste of water as needful, and test the Uguid as in the last Exp. It will be found that this treatment trans- forms saccharose into glucose, (and levulose.) The quantit tive 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 yol- ume 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 dis- charged. Experiment has demonstrated that one part of glucose or of levulose reduces 2.205 + parts of oxide of copper. Starch and sac- charose 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’ Quantiiiive 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 erys- tallization, 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 (Cio Ho O11.) + 2H20 = Cy Hy Org + Cig Hos Ore Oune-sugar. Water. Levulose. Glucose. 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 from the sorghum with such difficulty. Mo- lasses, 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- \ ot ie Oe fon THE VOLATILE PABT OF PLANTS. ri ture of the three sugars with some gum. The mannas of Syria and Kurdistan are of similar composition. The older observers assumed the preseuce of glucose in the bread grains. Thus Vauquelin found, or thought he found, 8.5°|, of this sugar in Odessa wheat. More recent-— ly, Peligot, Mitscherlich, and Stein have denied the pres- ence of any sugar in these grains. In his work on the Cereals and Bread, (Die Getreidearten und das Brod, 1860,) p. 163, Von 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 quan- tities of sugar. PROPORTIONS OF SUGAR IN AIR-DRY FLOUR, BRAN, AND MEAT. Per cent. MRC T AN OUI. Exp. 34.—Reduce several white turnips or beets to pulp by grating. Inclose tue 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. Bring the washed pulp into a elass vessel, with enough dilute chlorhydric acid, (1 part by bulk of commercial muriatie acid to 15 parts of water,) to saturate the mass, and let it stand 48 hours. Squeeze out, the acid liquid, filter it, anc 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 fer- ment 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 fruit- jellies. 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 be- come liquid when heated to boiling; on cooling, its solu. tion 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, THE VOLATILE PART OF PLANTS. R38 which remains in insoluble combination with oxide of copper. Metapectic acid.—By too iong 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 acd, 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 pect>se. Strain through muslin. The juice contains soluble pectin, which n.ay be precipitated from a small portion by alcohol. Keep the remaining juice heated to near the boiling point in a water bath, (i. e., by immersing the vessel containing it in a larger one of boil- ing 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 stand- ing 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—pectie acid—and on still fonger exposure to the same temperature, this jelly may dissolve again, by passing into Fremy’s metapectic acid, which alcohol does not precip- itate. Other ripe fruits, 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. Chemical composition of the Pectose group.—Our know!l- edge on this point is very imperfect. Pectose itself, hav- ing 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 formule of Fremy are as follows: Pectose, unknown. Pectin, Ceo Hay Ons + 4 Hy oO Pectosie acid, Cg H» Oy + 144 H,O Pectic acid, Cis Hao Ox, =e H, O Metapectic acid, Cs Hy O, + 2H,O Grouven, (2éer Salzmiinder Bericht, p. 470,) has prepar- ed pectin on the large scale from beet-root cake, (remaining after the juice was expressed for sugar manufacture,) b* 84 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 com- position, however, corresponded nearly with that assigned by Fremy to pecti acid, and differs somewhat from that given by this chex ist for pectin, as is seen from the suf joined figures: Pectin. Pectic acid. Grouven’s pectin. ¢ 32 Hys Osa Cie Hoe O15 WATDON es sacs) ae! 40.67 42.29 42.95 Hydrogen......... 5.08 4.84 5.44 Oxygen...........54.25 52.87 51.61 106 00 100.00 100.00 From the best analyses and from 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 formule (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 C,H,, 0, This nearness of composition assists in com- prehending the ease with which the transformations of pectose into the other members of the group 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. Sace, (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, Nivers, (Jour. Crem. Soc., 1863, p. 91,) has observed » suvstance 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, a ba ae THE VOLATILE PART OF PLANTS. &3 that in the living plant cellulose passes into pectose and pectin. Without loubt, also, the reverse transformations may be readily accomplished. 4, Tae Vecetraste Acips.—The Vegetable Acids are yery 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 owlic, tartaric, malic, and citric acids. They occur in plants either in the free state, or as salts of lime, potash, etc. They are mostly found in fruits. Oxalic acid, C, H, O, 2 H, O, exists largely in the com- mon 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 color- \ less, brilliant, transparen. crystals, not unlike Epsom salts in appearance, (Fig. 15,) but having an intensely sour taste. Oxalic acid forms with lime a sa/é—the 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, (Schmilt, Ann. Chem. u. Pharm., 61,297.) To- wards the end of the period of growth, it often accumu- lates 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 espe- cially 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 vhe name of salt of sorrel. Oxalic acid is now employed for this purpose. Oxalate of soda is soluble in water, and \ Fig. 15. 86 HOW CROPS 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. of hot water, add solutior 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 erystals of a salt of oxalic acid and ammonia—the oxalate of ammonia separate on cooling, the compound being sparingly soluble in cold wa- ver. Preserve for future use. Exp. 37.—Add to any solution of lime, as lime-water, (see note, p. 36,) cr hard well water, a few drops of oxalate of ammonia solution. Oxalate of lime immediately appears as a white powdery precipitate, which, from its extreme insolubility, serves to indicate the presence of the minutest quantities of lime. Addafew drops of chlorhydric or nitric acid to the oxalate of lime; it disappears. Hence oxalate of ammonia is a test fo lime only in solutions containing no free mineral acid. (Acetic anG oxalic acids, however, have little effect upon the test.) Definition of Acids, Buses, and Salts.—In the popular sense, an weid is any body having a sour taste. It is, in fact, true that all sour substances are acids, but all acids are not sour, some being tasteless, others bitter, and some sweet. A better characteristic of an acid is its capability of combining chemically with dases. Thestrongest acids, z. 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, ete. Bases are the opposite of acids. The strongest bases, when soluble, are bitter and biting to the taste, and cor- rode the skin. Potash, soda, ammonia, and lime, are ex- amples. Magnesia, oxide of iron, and many other com- pounds of metals with oxygen, are insoluble bases, and hence destitute of taste. Potash, soda, and ammonia, are termed alkalies ; lime and magnesia, alkali-earths. Salts are compounds of acids and bases, or at least re- sult 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 manner. Common salt—in THE VOLATILE PART OF PLANTS. 87 chemical language, chloride of sodium—is formed when soda is mixed with chlorhydric acid, water being, in this case, produced at the same time. Test for acids and alkalies.—Many vegetable colors are altered by solu- ble acids or soluble bases, (alkalies, ) in such 2 manner as to answer the purpose of distinguishing these two classes of bodies. A solution of eochineal may be employed. It has aruby-red color when concentrat- ed, but on mixing with much pure water, becomes orange or yellowish- orange. 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 200c. 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 an- other similar quantity add as many drops of ammonia. To the liquids add separately 5 drops of cochineal tincture, observing the coloration in each case. D vide the dilute ammonia into two portions, and pour into one of them tke dilute acid, until the carmine color just passes into orange. Should excess of acid have been incautiously used, add ammo- nia, 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 be found that the orange-cochineal indicates very minute quantities of ammonia, and tbe carmine-cochineal correspondingly small quantities ofacid. Tincture of litmus, (procurable of the apothecary,) or of dried ced cabbage, may also be employed. Litmus is made red by soluble ucids,and blue bysoluble 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 zach 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 col- ors. 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, sulphates of alumina, iron, and copper, have slightly acid caaracters. Certain acids form with the same base several distinct salts. Thus carbonic acid and soda may produce carbonate of soda, Na,zO CQs, or * Tinctures, in the language of the apothecary, are alcoholic solutions. 88 HOW CROPS GROW. bicarboaate of soda, Na HO CO,. The latter is mu th less alkaline than the former, but both turn cochineal to a carmine golor. Again, phos- phorie 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, H, O,, is the chief sour principle of ap- ples, currants, gooseberries, plums, cherries, strawberries, and most common fruits. It exists in small quantity in a multitude of plants. It is found abundantly in combina- tion 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 su- gar, 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 in water. Tartaric acid, C, H, O,, is abundant in the grape, from the juice of which, during fermentation, it is deposited in combination with potash as argol. This, Tea on purification, yields the cream of tartar, (bitartrate of potash,) of commerce. Tar- trates of potashor lime exist in small quantities in tamarinds, in the unripe ber- Fig. 16. ries of the mountain ash, in the berries of the sumach, in cucumbers, potatoes, pine-apples, and many other fruits. The acid itself may be obtained in large glassy crystals, (see lig. 16,) which are very sour to the taste. Citric acid, C, H, O,, 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 a a ea THE VOLATILE PART OF PLANTS, 89 lime, u. tobacco leaves, in the tubers of the Jerasalem artichoke, in the bulbs of onions, in beet roots, in coffee- berries, 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. felations of the Vegetable Acids to each other and to the Amyloids.—The four acids above noticed usually occur together in our ordinary fruits and it appears that some of them undergo mutual conversion in the liv ing plant. According to Liebie, the unripe berries of the mountain ash contain much tartaric acid, which, as the fruit ripens, is converted into malic acid. Schmidt, (Ann. Chem. u. Pharm., 114, 109,) first showed that tar- taric acid can be artificially transformed into malic acid. Tire chemical change ¢onsists merely in the removal of one atom of oxyyen. Tartaric acid. Matic acid. C, H,.O0.—O=(C, He O; 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. Com- mercial oxalic acid is thus made from starch and from saw-dust. Gum (Arabic,) sugar, starch, and, according to some, pectin, yield tar- taric acid by the action of nitric acid. 5. Fars anp Ous (Wax).—We have only space here to notice this important class of bodies in a very general manuer. 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, peanut, 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, con- tain 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 8) HOW CROPS GROW. as minute, transparent globules im the cells, f Frum these seeds the oil may be completely extracted by ether, += benzine, or sulphide of carbon, which dissolve all fats with readi- | ness, but scarcely affect the other vegetable principles. & JOC IC) Many plants: yield geal c HOUT COC OUOC TOON ERAT sea: q [ tities of wax, which either gives a [ glossy coat to their leaves, or forms 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 and wax, (Arendt). Scarcely two of these oils, fats, or kinds of wax, are exactly alike in their properti-~ They differ more or less in taste, odor, and consistency, as well as in their chemical composition. Exp. 39—Place a handful of fine and fresh corn or oat meal which has been dried foran hour or so at a heat not exceeding 212°, in a bottle. Pour on twice its buik of ether, cork tightly, and agitate frequently for half an hour. Drain off the liquid (filter, if need be) into a clean porce- lain 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 former, when pure, are without smell or taste. The latter usually pessess 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 consid- erable 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. ‘ a —— THE VOLATILE PART OF PLANTS. 9} tlowever greatly the various fats may differ in external « «acters, they are all mixtures of a few elementary fats. The most abundant and commonly occurring fats, espe cially those which are ingredients of the food of man and domestic animals, viz.: tallow, olive oil, and butter, con. sist 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 C,, H,,, O,. 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 solu- tion is obtainsu. wet cool slowly, when stearin will crystallize out in pearly scales. Palmitin, C,, H,, O,, receives its name from the palm cil, of Africa, in which it is a large ingredient. It forms a good part of butter, and is one of the chief con- stituents of bees-wax, and of bayberry tallow. Olein, C,, H,,, O,, 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 palimitin solidify, leaving the olein still in the liquid state. Other elementary fats, viz.: butyrin, laurin, myristin, ete., occur in small quantity in butter, and in various vegetable oils. Flaxseed oil eontains linolein; castor oil, ricinolein, ete. We have already given the formule of the principal fats, but for our purposes, a better idea of their composi tion may be gathered from a centesimal statement, viz. : * Margarin, formerly thought to be a distinct fat, is a mixture of stearin and pelmitin. 92 HOW CROPS GROW. CENTESIMAL COMPOSITION OF THE ELEMENTARY FATS, Stearin. Paimitin. Olein. Carbon, 76.6 75.9 TVA Hydrogen, 12.4 12.2 11.8 Oxygen, 10.0 11.9 10.8 100.0 100.0 100.0 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 con- tent of phosphorus. Von Bibra found the quantity.of phosphorus in this (impure) fat to range from 1.21 to 2.53 per cent. Knop (Vs. S¢. 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. 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Og $3 | OSs | S'6r 40 | SLL} OTL St | L6L 1 SOL | ‘uody | ..,,,--|"D2sar |, apreg | MT) ppp T9 nm CNOMme do m CMANDOM DRNAOS AoNron HANK Dra Dori rio} ppos’ ISTrl et | 9:98 | o°¥ 8718 1 8'8 oat 9°66:| 8 poe cE ele | Ler Lar | 96 9°18 | ¢°9r e0e | F6 Boe | ger 01% | OSE Tse | 6°OF 6°08 | g°1% Lh | Ocr ce | oor Lg | SE ee & 1 | B68 eet | Sor 20 | 08 -yso | "8Y 100 1-05) ee ‘[panuyuopJ—OI ‘SLONGOUd GNV SLNV1d TVYALTNOINDV ANOS AO HSV AHL JO NOILISOdKOO THE ASH OF PLANTS. 15? The composition of the ash of a number of ordinary crops is concisely exhibited in the subjoined general statement, Altealies, ©EG- Lame Phosphor- gorrg Sul, re ed nesta. * te Acid, CEREALS— Grain *,... 30 12 3 46 2 2.5 1 Straw...... 13—27 3 q 5 50—70 2.5 2 LraumMEs— Kernel ... 44 ¥ 5 85 1 4 g Straw...... 2741 q 25—39 8 5 2-6 6—? Root Crops— Roots... . 60 3-9 6-12 8-18 14 5—12 3-9 MODSiecess 37 3-16 10-3 3-8 3 6—13 5-17 GRaAssEs— In flower.. 33 4 8 8 35 4 5 3. Different 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 anal- yses of the parts of the mature oat-plant, by Arendt, 1 to 6, (Die Haferpflanze, p. 107,) and Norton, 7 to 9, (Am. Jour. Sci., 2 Ser. 3, 318.) a 3 4 Lower Mi date Upper Lower Upper ie Chat Husk. Kernel . f ae. a Stem. an . Leaves, husked. PRS er ctalpe acters ens « 81.2 8.e 55.9 36 24.8 13.0 a Ge hi Aap 0:9". “0:4 Oot + 10.6 12.4 31.7 Magnesia male ialetaiiexsiss7 2.1 3.6 3.9 3.8 3.9 8.9 ] 2.3 8.6 ESO ics Sec we era. 5.3 So. 16.7% * PR %.3 11.2 4.3 5.3 Oxide of Iron. tO. 0.0," 0:2. °2.% 0.5 ne) 0.8 > os Phosphoric acid Oe aa OO a Leon 286.0 0.6 49.1 Sul huricacid eOlO.,.- wea | est 3.25) ON.6 14:9) 58, 1453 1/056 PENI oi aia cig sv Aad O53 (24 84.0 4158 26:0 (68:0) Yaet 1.8 Chlorine......... See ie me bi tire 1.4 1.6 2.4 3.8 Sk a 0.2 The results of Arendt and Norton are not in all respects strictly com- parable, 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 °|,.) This alkali is pre- dominant 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 pf the leaves, * Exclusive oi husk. 158 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, (82 °|,,) and considerable mag: nesia. Chlorine acquires its maximum, (11.7°|,,) 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. Jahresbe- richt, 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: I. 10 Til. IV. V. Otasheracteacie\saie/ - 938.028 1000. 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 trans- ferred 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 prep- aration has been described, may be turbid from the sepa- ration of a little white sulphate of lime before the last dilu- tion, as well as from the precipitation of phosphate of iron mM. adding sulphate of iron. The foriner 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 8 170 WOW 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 sceds. (Vs. Sé., VIL, 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 grain- bearing stalks. (Vs. S¢., VII, 72.) In water-culture, the composition of the solution is suf fering continual alteration, from the fact that the plant makes, to a certain extent, a selection of the matters pre- sented 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 Knop, 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 free 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 THE ASH OF PLANTS. 171 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, (JZenneberg’s Journal, 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-cul- ture, when the liquid contains more than *|,,,, of solid mat- ters, 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 suf: ficiently often. Sachs’ earliest experiments were made with well-water. Birner and Lucanus, in 1864, ( Vs. S¢., 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, con- tained in 100.000 parts: 2 i i 2.10 Lime - - - - - - 15.10 Magnesia - = - - - 1.50 Phosphoric acid - - - - 0.16 Sulphuric acid) - - - = 7.50 Mianeacid - - = - «= 6.00 Silica, Chlorine, Oxide of iron - - traces 0 | Water - - - - - - - - 99,967.64 100,000 — Nobbe, (Vs S¢., VIII, 337,) found that in a solution con- taining but ’*|,,,,, of solid matters, which was continually 172 HOW CROPs GROW. renewed, varley made no progress beyond ge mination, and 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 fune- tions 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 Sul- phuric Acid, are absolutely necessary for the life of Agricultural Plants, as is demonstrated by all the experi- ments 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 Salm- Horstmar, Sachs, Knop, and others. (See, especially, Birner & Lucanus, Vs. S¢., 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, Bichon found in the ash of the pea 13, in that of the bean i9, in that of rye 19, in that of wheat 27 per cent of soda. HUcrapath found 15 per cent of this substance in wheat-ash, and 20 per cent in ash of rye. Brewer found 13 per cent in the ash of maize. Ina few other analyses of the grains, we find similar high per- centages. In most of the analyses, however, soda is pres- ent 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. THE ASH OF PLANTS. 173 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 custom. arily empioyed 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 muc!: potash; while on the other hand, soda, if pres- ent to the extent of a per cent or more, is very liabie to be estimated too high. It has therefore been doubted if these high percentages in the ash of grains are correvt. 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 deubt 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-sclected 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 ush of several field crops, according to the newest analyses: Ash of Wheat kernel none, Bibra, to 5°], Bibra. ? C za “ Potato tuber, none, i Matodorit “401, Wolff. ’ ae Bibra. “© Barley kernel i a ae te 604 Veltmann. ’ : 7|, Zoeller. “ww 4.7°|, Ritthausen, ‘* 298°|, Ritthausen, Sugar beet, 5.7| 9 Bretschneider“ 16.6°|) Bretschneider « Turnip root, %.%|, Anderson, ‘ 17.1%, Anderson 174 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 entire plant 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 ab- sent, it is simply implied that it is present in wnweighable guantity,* 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 ingre- dient of the ash of plants, and though generally present in some proportion, and often in large proportion, has been observed to be absent in weighable quantity in the seeds of grains and in the tubers of potatoes. Salm-Horstmar, Stohmann, Knop, and Nobbe & Sie- gert, 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 * Unweighable quantities are designated as ‘‘ trace’’ or ‘* traces.” + The newly discovered methods of spectral analysis, by which saan TTT 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. THE ASH OF PLANTS. 175 substances employed. He gives as the result of numerous experiments, that for wheat, oats, and barley, 7m the early vegetative stages of growth, soda, while advantageous, ws not essential, but that for the perfection of fruit an ap- preciable though minute quantity of this substance is in- dispensable. (Versuche und Resultate tiber die Nahrung der Pflanzen, pp. 12, 27, 29, 36.) Stohmann’s single experiment led to the similar conclu- sion, that maize may dispense with soda in the earlier stages of its growth, but requires it for a full development. (Henneberg’s Jour. fir 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. S¢., 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 demon- strate that a trace of sodais 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 te 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 éotally absent from plants, but that, 2. If indispensable, but a minute amount of it 1s re quisite %. That the foliage and succulent portions of the plant 176 HOW CROPS GROW. may include a considerable amount of soda that is not nee essary to the plant, that is, in other words, accidental.* Can Soda replace Potash 3—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 as- sumption 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 lat- ter almost destitute of this substance, but contained cor- respondingly more potash. Two analyses of the ash of the beet, one by Wolff, (1.,) the other by Way, (2.,) ex. hibit similar differences : Asparagus. Field Beet. Wild. Cultivated. ic 2. ORAS as eels ls oe Bona kcks) 50.5 57.0 25.1 CGH a= Connon aooceanaor 16.2 trace 7.3 34.1 nla ASR pp oeaean acc 28.1 21.3 5.8 2.2 MIGEMCBIM ciatavcic(s sis)= alates L5 — 4.0 2.1 (AT HOT RIN ope a nocapecrn 16.5 8.3 4.9 34.8 Sulphuric acid......... 9.2 4.5 3.5 3.6 Phosphoric acid....... 12.8 12. 12.9 1.9 PSEC Mares terevercisis\a.s nin, satatele 1.0 3.7 3.7 LG These results go to show—it being assumed that only a very minute amount of soda, if any, is absolutely neces sary 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 18 derived, indirectly at least, from the vegetable kingdom, it is a wiee provision that soda is contained én, if it be not indispensable to plants. THE ASH OF PLANTS. 17 dental 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 com- position 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, Sali cornia, are plants, which, unlike those just mentioned, never stray inland. Gdbel, who has analyzed these plants as occurring on the Caspian steppes, found in the soluble part of the ash of the Salsola 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 ‘| ,, and in the latter ’|,, 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, 3te Auf., p. 66.) According to Cadet, (Liebig’s Erndhrung der Veg., 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 sea- water is but *|,, that of the soda, it is yet a fact, as shown by the analyses of Forchhammer, (Jour fiir Prakt. Chem., * This is net, indeed, proved by analysis, in case of the carrot, but is doubt less true. ’ 8* 178 HOW CROPS GROW. 36, p. 391,) and Anderson, (Zrans. High. and Ag. Soe., 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 thn soda of the sea-weeds is in a great degree acci- dental, although, necessarily, special investigations are re- quired to establish a point like this. Oxide of Iron is essential to plants.—It is abundant- ly proved that a minute quantity of oxide of iron, Fe, O,, 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, the protowide of iron is indispen- sable to the colza plant. ( Versuche, etc., p. 35.) Knop as certs 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. (Vs. Sé. 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 asually 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 3°|,. In root crops it aas been found as high as 5°|,.. Kekule found in the ash of gluten from wheat 7.1°|, of oxide of iron. (Jahres bericht der Chem., 1851, p. 715.) Schulz-Fleeth found 17.5°|, in the ash of the albumin from the juice of the 0 * Doubtless due to the fact that the material used by Anderson was freed by washing from adhering common salt, THE ASH OF PLANTS. 179 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°|,. The largest percentages have been found in aquatic plants. In the ash of the duck-meat, (Lemna trisulca,) Liebig found 7.4°|,. Gorup-Besanez found in the ash of the leaves of the Zrapa natans 29.6"|,, and in the ash of the fruit-envelope of the same plant 68.6°|,. (Ann. Ch. Ph., 118. p. 223.) Probably much of the iron of agricultural and land plants is accidental. In case of the Z’rapa natans, we cannot suppose all the oxide of iron to be essential, be cause the larger share of it exists in the tissues as a brown powder, which may be extracted by acids, and has the ap- pearance of having accumulated there mechanically. Doubtless a portion of the oxide of éron 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, Mn, 0,, is unessential to Agri- cultural 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 quan- tity. Thus, in the ash of Zrapa, it was found to the extent of 7.5-14.7°| .. Sometimes it is found in much larger quar. tity than oxide of iron; e. g., C. Fresenius found 11.2°|, of oxide of manganese in ash of leaves of the red beech, (Fagus sylvatica,) that contained but 1°|, of oxide of ircn, In the ash of oak leaves, ( Quercus robur,) Neubauer found, of the former 6.6, of the latter but 1.2°|,. In ash of the wood of the larch, (Larix Huropea,) Béttinger found 13.5°|, Mn, O, and 4.2’|, Fe, O,, and in 180 HOW CROPS GROW. ash of wood of Pinus sylvestris 18.2°|, Mn, O,, and 3.5°|, Fe, O,. In ash of the seed of colza, Nitzsch found 16.1°| Mn, O, and 5.5 Fe, O,. In case of land plants, these high percentages are accidental, and specimens of most 2f 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 devel- opment 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 Chierine indispensable to Crops?—What has been written of the occurrence of soda in plants ap- pears to apply in most respects equally well to chlo- rine. In nature, soda, or rather sodium, is generally associated with chlorine as common salt. It is most prob- ably 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 exi'ts in correspond- ing quantity. Less commonly, the chlor ine of plants is in combination with potassium exclusively. Chlorine is doubtless never absent fro: 1 the perfect agri- cultural plant, as produced under natural conditions, though its quantity is liable to great variation, and is often very small—gso small as to be overlooked, exvept by the careful analyst. In many analyses of grain, chlorine is not men- tioned. Its absence, in many cases, is due, without doubt, to the fact that chlorine is readily dissipated from the ash of substanees 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 THE ASH OF PLANTS. 1s] 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, chlo- rine 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 0.08? |,, 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 0.7°|,. Weber’s analysis, as compared with the others, would indicate a considerable range of variability. Weber extracted the charred ash with water, and found 6°|, of chlorine, which is six times as much as is given in any other recorded anal- ysis 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 accom- panies soda in strand and marine plants, and, in general, the content of chlorine of any plant may be largely in- creased or diminished by supplying it to, or withholding it from the roots. As to the indispensableness of chlorine, we have some- what conflicting data. Salm-Horstmar concludes that a trace of it is needful to the wheat plant, though many of his experiments in reference to the importance of this ele- ment 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 chlorme from the 182 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 buck wheat. (Vs. S¢., VIII, 177.) From a series of experiments in water-culture, Birner & Lucanus, (Vs. Sé., VIL, 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 stem, chloride of mag- nesium was positively deleterious, under the conditions of their trials. Lucanus, (Vs. Sé., VII, 363-71,) raised clover by wa- ter-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 con- taining 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 agricultural plants, 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 ch orine that is not indispensable to the life of the plant a THE ASH OF PLANTS. 183 Necessity of Chlorine for Strand Plants.—A single observation of Wiegmann and Polstorf, (Preisschri/t,) indicates that Salsola kali requires chlorine, though whether it be united to potassium or sodium is indiffer- ent. 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 chlo- ride of potassium. The plants grew most luxuriantly blossomed, and completely filled the pot. They were then put out into the earth, without receiving further ap- plications of chlorine-compounds, but the next year they became unhealthy, and perished at the time of blossoming. Silica is net 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 natural soils. In the ash of the wood of trees, it usually ranges from 1 to 3°|,, but is often found to the extent of 10-20°|,, or even 30°| ,, especially in the pine. In leaves, it is usually more abundant than in stems. The ash of turnip-leaves contains 3-10°|, ; of tobacco-leaves, 5-18"|,; of the oat, 11- 58°|,. (Arendt, Norton.) In ash of lettuce, 20°|, ; of beech leaves, 26°|,; in those of oak, 31°|, have been observed. (Wicke, Henneberg’s Jour., 1862, p. 156.) The hark or cuticle of many plants contains an extraor- dinary amount of silica, The Cauto tree, of South America, (Hirtelia 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°|, of ash, and of this 96°|, 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°|,, and in the joints of the stem are often found concretions of silica, re sembling flint—the so-called Zabashir. 184 HOW CROPS Grow. The ash of the common scouring rush, (Zgzisetum hye male,) has been found to contain 97.5°|, of silica. The straw of the cereal grains, and the stems and leaves of grasses, both belonging to the botanical family Graminee, are specially characterized by a large content of silica, ranging from 40 to 70°|,. 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 sur- face. 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. He found in Wood of a tree, 220 years old, 32.5°|- “ce Sass Ses () 24.1 LCR ee sie ee Caen Sei herr) ha Bark LG\CE TEE 920 (73 “ 30.3 “ uw oe 7 Od 6) ORES 2 ER Tt hee “Cry waited In the ash of the straw of the oat, Arendt found the per- centage of silica to increase as the plant approached maturi- ty. 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, aud 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 THE ASH OF PLANTS. 185 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 lone been known in case of the Equisetums and Deutzias. Here, the roughnesses of the stems or leaves which make these plants aseful for scouring, are fully incrusted or interpenetrated by silica, and the ashes of the cuticle present the same ap- pearance 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, (Musa teatilis,) aioe-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 de- gree 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 ; 8.382; 9.77; 21.385. Analyses of the ash of 9 samples of colza-straw, all produced from the same seed on differ ent soils, gave the following percentages: 1.00; 1.14; 3.02; 3.57; 4.65; 508; 7.81; 11.88; 17.12. (Journal fir praké. 186 HOW CROPS GROW. Chem., xlviii, 474-7.) Such instances might be greatly niultiplied. The idea that a part of the silica is accidental is further sustained by the fact observed by Saussure, the earliest in- vestigator of the composition of the ash of plants, (e- cherches sur la Vegetation, p. 282,) that crops raised on 1 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 potato- oat 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 ex- cepted, not only grew well, but contained in its ash 23°], 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 indi- cating 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 con- tained but 0.7°|, of silica. Shortly afterwards, Knop pro- duced 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 milli- grammes in the 15 leaves and sheaths. It was altogether absent from the seeds, The ash of the leaves of this plant thus containel but 0.54 per cent of silica, and the stem but 0.07 per cent. Way & Ogston found in the ash of naize, leaf and stem together, 27.98 per cent of silica, YFHE ASH OF PLANTS. 182 KXnop inclined to believe that the little silica he found m his maize plant was due to dust, and did not belong to the tissues of the plant. He remarked, “I believe that silica is not to be classed among the nutritive elements of the Graminex, 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 & Kiihn, 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, (Vs. St, VIII, p. 200,) obtained it the ash of maize thus cultivated, 2—3°|, of silica, while the same two varieties from the field contained in their ash 113—13°|,. The proportion of ash was essentially the same in both cases, viz., about 6°|,. Wolff’s results with the oat plant were entirely similar. Birner & Lucanus, (Vs. S¢., VII, 141,) found that the supply of soluble silicates to the oat made its ash very rich in silica, (40°|,,) 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 httle 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 188 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 ex: posed to air 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-in- gredients 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 mag- nesia, chloride of calcium, phosphate and nitrate of potash, with phosphate of iron, which together constituted 0,316°| of the liquid.) The ash-percentage was much higher im THE ASH OF PLANTS. 189 the water-plants than in the garden-plants, as shown by the subjoined figures. (Vs. St., V, p. 182.) Per cent of ash in Stems and Leaves. Roots. Seeds, Entire Plant. Water-plant..... 18.6 15.3 2.6 16.7 Garden-plant.... 8.7 6.8 2.4 eke 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 *|, 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 them- selves, and also incapable of forming insoluble combina- tions 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, grow- ing in the garden, as well as with buckwheat and barley . m water-culture. (Vs. S¢t., VI, p. 37.) Saussure found in the white incrustations upon cucum- ber leaves, besides an organic body insoluble in water and aleohol, chloride of calcium, with a trace of chlo- ride of magnesium. The organic substance sc enveloped the chloride of calcium as to prevent deliquescence of the latter. (Recherches sur la Veg., p. 265.) 190 HOW CROPS GROW. Saussure proved that foliage readily yields up saline matters to water. He placed hazel leaves eight successive times in renewed portions of pure water, leaving them therein 15 minutes each time, and found that by this treat- ment they lost ‘|,, of their ash-ingredients. The por- tion 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 after being cut, may lose by washing more than ’|, of its ash-ingredients. Mulder, (Chemie der Ackerkrume, I, p. 305,) attributes to loss by rain a considerable share of the variations in per- centage 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 extent 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 insolu- ble in the plant, viz., the sulphate of lime, the oxalates, phos- phates, and carbonates of lime and magnesia, the oxides of iron and manganese, and silica, may be deposited as crys tals or concretions in the cells, or may incrust the cell- walls, 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 vuticle of the kernels of cereals--phosphate of magnesia THE ASH OF PLANTS. 191 exists in comparatively large quantity. In the dense teak wood, concretions of phosphate of lime have been noticed. Of a certain species of cactus, (Cactus senilis,) 80°|, 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 nourish- ing medium in which the plant grows has been obsery- el 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 erys- tals and globular crystalline masses, consisting probably of oxalates and phosphates of lime and magnesia, depos- ited in the rind and pith; but that these were by far most abundant in the water-plants, whose ash-percentage was twice as great as that of the land-plants. These insoluble substances may either be entirely unes- sential, 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 re- moved 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 tlie 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 en- eysted in the living cells. The occurrence of crystallized salts thus segregated in the cells of plants is illustrated by the following cuts. Fig. 23 represents a crystallized concretion of oxalate of lime, having a basis or skeleton of ccllulose, from a leaf ofthe walnut. (Payen, Chimie Industrielle Pl. XIL) 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. 192 HOW CROPS GROW. In the root of the young bean, Sachs found a ring of cells, containing crystals of sulphate of lime. (Sitzwngsberichte der Wien. Akad., 37, p. 106.) Bailey observed in certain 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. 20. 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 cell- wall. In certain plants, other substances accumulate in considerable quantity without the cuticle. A striking ex- ample is furnished by Saxifraga crustata, alow European plant, which is found in lime soils. The leaves of this saxifrage are entirely coated with a scaly in- crustation of carbonate of lime and carbonate of magnesia. At the edges of the leaf, this incrusta- tion acquires a considerable thick- ness, as is illustrated by figure 26, a. Inan analysis made by Unger, to whom these facts are due, the fresh, (undried,) leaves yielded to a dilute acid 4.14°|, of carbonate of lime, and 0.82°|, of carbonate of magnesia. Unger learned by microscopic 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. (Sitzberichte der Wien, Akad., 48, p. 519.) THE ASH OF PLANTS. 193 In figure 26, a represents the appearance of a leaf, magnified 414 diam- eteis. 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: 6 shows a leaf, freed from its incrustation by an acid, and from its cuticle by potash- solution, so as to exhibit the veins, (ducts,) and glands, whose course ‘he 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 plants in the forms under which they are otherwise familiar 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 from 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 in 10,000 of the dry plant. ( Wachsthum der Haferpflanze, pp. 168, 183-4. See, also, table on p. 198.) Weiss and Wiesner have found by microchemical 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 graén in this way was impossible. 9 194 HOW CROPS GROW. the leaf-stalks less, and the stems least. He obtained, among others, the following results. (Vs. Sé, IV, p. 59.) Of 100 parts of the following fixed ingredients of clover, were dissolved in the sap, and not dissolved— In young leaves. In full-grown leaves, 2 37.3 dissolved: i.) ne. 7 Potask | undissolved....... 24.8 62.7 A dissolvediacec css 69.5 72.4 Lime | undissolved.......30.5 27.6 es dissolved asic ies 43.6 78.3 Magnesia | undissolved....... 56.4 21.7 Phos ee ic j dISSOlVEM <2. cfe <6 100 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 COMPOSITION IN SUCCESSIVE STAGKS. 209 first stages of ripening, but falls off at last to minimum. The ratio of Oxygen to Carbon is the same during the Ist 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 2li 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 arate equal to that at which the fixed matters (asl) are absorbed. In the first period Nitrogen and Ash; in the fourth period Nitrogen and Oxygen; in the fifth pe- riud Oxygen and Ash are assimilated in largest propor- tion. This is made evident by calculating for each pcriod the Daily Increase of Each Ingredient, the amount of the in- gredients in the ripe plant being assumed at 100 as a point of comparison. The figures resulting from such a calcula- tion are given in TaBLE IX.—Br. Carbon. Hydrogen. Oxygen. Nitrogen. dsh. 1st Period, 0.31 0.33 0.28 0.47 0.50 3d Ke 2.51 2.68 2.17 2.59 2.13 4th “ 0.89 0.88 1.07 1.06 0.47 Sth “ 1.49 1.16 1.89 0.75 1.70 The increased assimilation of the 5th over the 4th period is, in all probability, only apparent. The results of anal- ysis, as before mentioned, refer only to those parts of the plant that are above ground. The activity of tae foliage in gathering food from the atmosphere is doubtlexs 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 assimilatir g inorganic food (CO,, H,O, NH,, N,O,) is lost. 270 HOW CROPS GRuW. The following statement exhibits the Average Daily In- crease of Carbon, Hydrogen, Oxygen, Nitrogen, and Ash, (in Ibs. per acre) during the several periods, TABLE X.—Br. Carbon. Hydrogen. Oxygen. Nitrogen. Ash. {st Period, 8.438 1.18 6.30 0.65 1.56 3d + 66.95 8.94 48.06 3.30 6.55 4th “ 23.84 2.95 24.06 147 1.44 apitie C8 39.85 3.89 42.44 1.04 5.23 Turning now to Arendt’s results, which are carried more ‘nto 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 + is found in greatest relative quantity—40° |,— in 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°|,, at heading, to 12°|,, at maturity. In the leaves, which, as regards fiber, stand intermediate between the stem and ear, this substance ranges from 22°|, to 38°|, 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. und analyzed each part separately. His divisions of the plants were 1, the three lowest joints of the stem; 2, the two middle joints; 8, 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. 1 i. e., Crude cellulose ; see p. 60. COMPOSITION LN SUCCESSIVE STAGES. 211 (33’|,,) is found in the 4th; in the upper leaves, (38°|, ) in the 2d period. The apparent diminution in amount of fiber is due in all cases to increased production of other ingredients, 2, Hat and Waz 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°|, to 3°|,. In the ear the proportion in- creases from 2"|, to 3.7°|,. In the leaves the quantity is much larger and is mostly wax. The smallest proportion is 4,8°|,, which is found in the upper leaves, when the plant is ripe. The largest proportion, (10°|,,) exists in the lower leaves, at the time of blossom. The relative quantities found in the leaves undergo considerable varia- tion from one stage of growth to another. 3. Non-nitrogenous matters, other than fiber,—starch, sugar, etc.,*—undergo great and irregular variation. In the stem the largest percentage, (57°|,,) is found in the young lower joints; the smallest, (43°|,,) in ripe upper straw. Only in the ear occurs a regular increase, viz., from 54 to 63°]. 4, The Albuminoids,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. If 10 rT IV. We PATON Gi icicic sis oc.08 20.93 11.65 10.86 13.67 14.30 Bretschueider..... 22.73 17.67 17.61 1539 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 anh, from the dry substance, is here included. + Calculated by multiplying the percentage of nitrogen by 6.33. 212 HOW CKOPS 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 tke plant is greatly modified by the circumstances of its growth, not only in reference to its external figure, but ake 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 fluc- tuations, (relative,) in the content of this element. The percentages are arranged for each period separately, pro- ceeding from the highest to the lowest: PERIODS. I. II. III. IV. Vi 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. 1.52 1.34 1.60 1.43 Upper stem. Middle stem. Middie 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. iL TT: Oe IV. Vie Bretschneider ......8.57 5.96 5.33 5.40 Avendti cis. sds ass 8.03 5.24 5.44 5.20 5.17 The diminution at the 2d, increase at the 3d, and sub- sequent diminution at the 4th period, are observed to run parallel in both cases. As regards the several parts of the plant, it was found COMPOSITION IN SUCCESSIVE STAGES. 218 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 towards the time of ripening. The greatest percentage, (10. 5° lo) was found in the ripe leaves; the smallest, (0.78°|,,) 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, ds not accord with those obtained by Bretschnei- der 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 rep- resent the crop as obtained in farming, those of Arendt give a truer idea of the plant when sitnated 9 in the best possible conditions, and attaining a uniformly high development. We shall not attempt to compare the two sets of observa tions, since, strictly speaking, in most points they do not admit of comparison. From a knowledge of the absolute quantities of the gub- stances contained in the plant at the ends of several periods, we may at once estimate the rate of growth, 7. ¢., the rapid- it, 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 perinls, and, (by subtracting the first from the 214 HOW CROPS GROW. second, the second from the third, etc.,) the gain from matters absorbed or produced during each period, wil. 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 EntrrE PLANTS, (WATER-FREE.) . @e8e le clSs.le clSsele ulSgela ulSge BSo 8815, Co 88/2, Slo S38/3. Sloss ]2.2 ass SSSVSIESTISESIGSTISSSISSVISSSIERTISES SB°OSsslE$SISsy <=/Ss > Mt TM /| * For experimenting on small plants, a simple tube of glass may be adjusted to the stump vertically by help of a rubber connector. EE THE VEGETATIVE ORGANS VF PLANTS, 249 Bean (Phaseolus multiflorus) 6 inches of mercury. es ae ee ) : ss a i a pe ee ‘Seat of Absorptive Force.—Dutrochet demonstrated that this power resides in the surface of the young and active roots. At least, he found that absorption was ex- erted with as much force when the gauge was applied to near the lower extremity of a root, as when attached_in the vicinity of the stem. In fact, when other conditions are alike, the column of liquid sustained by the roots of a plant is greater, the less the length of stem that remains attached to them. The stem thus resists the rise of liquid in the plant. While the seat of absorptive power in the root lies near the extremities, it appears from the experiments of Ohlerts that the extremities themselves are incapable of imbibing water. In trials with young pea, flax, lupine, and horse- radish plants with unbranched roots, he found that they withered speedily when the tips of the roots were immers- ed for about one-fourth of an inch in water, the remaining parts being in moist air. Ohlerts likewise proved that these plants flourish when only the middle part of their roots is immersed in water. Keeping the root-tips, the so-called spongioles, in the air, or cutting them away alto- gether, was without apparent effect on the freshness and vigor of the plants. The absorbing surface would thus appear to be confined to those portions of the root upon which the development of root-hairs is noticed, The absorbent force is manifested by the active rootlets, and most vigorously when these are in the state of mast rapid development, For this reason we find, in case of t!.e vine, for example, that during the autumn, when tie plant is entering upon a period of repose from growth, the ab sorbent power is trifling. The effect of this forcible en. trance of water into the plant 1s oftentimes to cause the 1* 250 HOW CROPS GROW. exudation of it in drops upon the foliage. This may be noticed upon newly sprouted maize, or other cereal plants, where the water escapes from the leaves at their extreme tips, especially when the germination has proceeded under the most favorable conditions for rapid developinent. The bleeding of the vine, when severed in the spring: time, the abundant flow of sap from the sugar-maple, and the water-elm, are striking illustrations of this imbibition of water from the soil by the roots. These examples are, indeed, exceptional in degree, but not in kind. Hofmeister has shown that the bleeding of a severed stump is a gen- eral fact, and occurs with all plants when the roots are active, when the soil can supply them abundantly with water, and when the tissues above the absorbent parts are full of this liquid. When it is otherwise, water may be absorbed from the gauge into the stem and large roots, un- til the conditions of activity are renewed. Of the external circumstances that influence the absurp- tive power of the root, may be noticed that of tempera- ture. By observing a gauge attached to the stump of a plant during a clear summer day, it will be usually no- ticed that the mercury begins to rise in the morning as the sun warms the soil, and continues to ascend for a num- ber of hours, but falls again as the sun declines. Sachs found in some of his experiments that at a temperature of 41° F., absorption, in case of tobacco and squash plants, was nearly or entirely suppressed, but was at once renewed by plunging the pot into warm water. The external supplies of water,—in case a plant is sta- tioned in the soil, the degree of moisture contained in this medium,—obviously must influence, not perhaps the im- biking force, but its manifestation. The Rate of Absorption is subject to changes depend- ent on other causes not well understood. Sachs observed that the amount of liquid which issued froin potato stalke 2 THE VEGETATIVE ORGANS OF PLANTS. 251 cut off just above the ground, underwent great and con- tinual variation from hour to hour (during rainy weather) when the soil was saturated with water and when the thermometer indicated a constant temperature. Hofmeister states that the formation of new roots and buds on the stump is accompanied by a sinking of the water in the pressure-gauge. Absorption of Nutriment from the Soil.—The food of the plant, so far as it is derived from the soil, enters it in a state of solution, and is absorbed with the water which is taken up by the force acting in the rootlets. The absorp- tion of the matters dissolved in water is in some degree independent of the absorption of the water itself, the plant having, to a certain extent, a selective power. 3. The Root as a Magazine.—In fleshy roots, like those of the carrot, beet, and turnip, the absorption of nutriment from the soil takes place principally, if not en- tirely, by means of the slender rootlets which proceed abundantly from all parts of the main or tap-root, and es- pecially from its lower extremity ; while the fleshy portion serves as a2 magazine in which large quantities of pectose, sugar, etc., are stored up during the first year’s growth ot these, (in our latitude,) biennial plants, to supply the wants of the flowers and seed which are developed the second year. When one of these roots is put in the ground for a second year and produces seed, it is found to be quite exhausted of the nutritive matters which it pre- viously contained in so large quantity. In cultivation, the farmer not only greatly increases the size of these roots and the stores of organic nutritive ma- terials they contain, but by removing them from the ground in autumn, he employs to feed himself and his cat- tle the substances that nature primarily designed to nour- ish the grewth of flowers and seeds during another sum- mer. 952 HOW CROPS GROW. Soil-Roots: Water-Roots: Air-Roots.—We may dis: tinguish, according to the medium in which they are formed and grow, three kinds of roots, viz.: sozl-roots, water-roots, and «atr-roots, Most agricultural plants, and indeed by far the greater number of all plants found in temperate climates, have roots adapted exclusively to the soil, and which perish by drying, if long exposed to air, or rot, if immersed for a time in water. Many aquatic plants, on the other hand, die if their roots be removed from water, or from earth saturated with water. Air-roots are not common except among tropical plants. Indian corn, however, often throws out roots from the lower joints of the stem, which extend through the air several inches before they reach the soil. The Banyan of India sends out roots from its branches, which penetrate the earth in like manner. Many tropical plants, especially of the tribe of Orchids, emit roots which hang free in the air, aud never come in contact with water or soil. A plant, known to botanists as the Zamia spiralis, not only throws out air-roots, ¢ c, Fig. 44, from the crown of the main soil-root, but the side rootlets, 4, after extending some distance horizontally in the soil, send from the same point, roots downward and upward, the latter of which, d, pass into and remain permanently in the air, A is the stem of the plant. (Schacht, Anatomie der Gewdchse, Bd. II, p. 151.) Some plants have roots which are equally able. to exist and perform their functions, whether in the soil or sub- merged in water. Many forms of vegetation found in our swamps and marshes are of this kind. Of agricul- tural plants, rice isan example in point. Rice will grow in a soil of ordinary character, in respect of moisture, as the upland cotton-soils, or even the pine-barrens of the Carolinas, It flourishes admirably in the tide swamps of THE VEGETATIVE ORGANS OF PLANTS. 2538 the coast, where the land is laid under water for weeks at a time during its growth, and it succeeds equally well in fields which are flowed from the time of planting to that of harvesting. (Russell. Morth America, its Agriculture and Climate, p. 176.) The willow and alder, trees which grow on the margins of streams, send a part of their roots into soil that is constantly saturated with water, or into ° Fig. 44. the water itself; while others occupy the merely moist or even dry earth. Plants that customarily confine their growth to the soil, occasionally throw out roots as if in search of water, and sometimes choke up drain-pipes or even wells, by the pro- fusion of water-roots which they emit. At Welbeck, England, a drain was completely stopped by roots of horseradish plants at a depth of 7 feet. At Thornsby Park, a drain 16 feet deep was stopped en 254 HOW CROPS GROW. tirely by the roots of gorse, growing at a distance of 6 feet from the drain. (Jour. Roy. Ag. Soc., 1, 364.) In New Haven, Conn., certain wells are so obstructed by the aquatic roots of the elm trees, as to require cleaning out every two or three years. This aquatic tendency has been repeatedly observed ir tke poplar, cypress, laurel, turnip, mangel-wurzel, and Grasses. Henrici surmised that the roots which most cultivated plants send down deep into the soil, even when the latter is by no means porous or inviting, are designed especially to bring up water from the subsoil for the use of the plant. The following experiment was devised for the purpose of testing the truth of this view. On the 13th of May, 1862, a young raspberry plant, having but two leaves, was transplanted into a large glass funnel filled with gar- den soil, the throat of the funnel being closed with a paper filter. The funnel was supported in the mouth of a large glass jar, and its neck reached nearly to the bottom of the latter, where it just dipped into a quantity of water. The soil in the funnel was at first kept moderately moist by occasional waterings. The plant remained fresh and slowly grew, putting forth new leaves. After the lapse of several weeks, four strong roots penetrated the filter and extended down the empty funnel-neck, through which they emerged, on the 21st of June, and thenceforward spread rapidly in the water of the jar. From this time on, the soil was not watered any more, but care was taken to maintain the supply in the jar. The plant continued to develope slowly; its leaves, however, did not acquire a vivid green color, but remained pale and yellowish; they did not wither until the usual time late in autumn. The roots continued to grow, and filled the water more and more. Near the end of December the plant had 7-8 leaves, and a height of 8 inches The water-roots were vigorous, very long, and beset with numerous fibrils and. THE VEGETATIVE ORGANS OF PLANTS. 255 buds. In the funnel tube the roots made a perfiut tissue of fibers. In the dry earth of the funnel they were less extensively developed, yet exhibited some juicy buds, The stem and the young axillary leaf-buds were also full of sap. The water-roots being cut away, the plant was put into garden soil and placed in a conservatory, where it grew vigorously, and in May bore two offshoots. The experiment would indicate that plants may extend a portion of their roots into the subsoil chiefly for the pur- pose of gathering supplies of water. (Henneberg’s Jour. Sir Landwirthschaft, 1863, p. 280.) This growth towards water must be accounted for on the principles asserted in the paragraph—Apparent Search for Food, (p. 241). The seeds of many ordinary land plants—of plants, in- deed, that customarily grow in a dry soil, such as the bean, squash, maize, etc.,—will readily germinate in moist cot- ton or saw-dust, and if, when fairly sprouted, the young plants have their roots suspended in water, taking care that the seed and stem are kept above the liquid, they will continue to grow, and if duly supplied with nutriment will run through all the customary stages of development, producing abundant foliage, flowering, and perfecting seeds, without a moment’s contact of their roots with any soil. (See Water Culture, p. 167.) Ii plants thus growing with their roots in a liquid me- diuta, after they have formed several large leaves, be care- fully transplanted to the soil, they wilt and perish, unless freyuently watered ; whereas similar plants started in the soil, may be transplanted without suffering 1 the sliyht- est degree, though the soil be of the usual dryness, and receive no water. The water-bred seedlings, if abundantly watered as often as the foliage wilts, recover themselves after a time, and thenceforward continue to grow without the need of watering. Is might appear that the first-formed water-roots are in 956 HOW CROPS GROW. capable of feeding the plant from a dry soil, and hence the soil must be at first profusely watered; after a time, however, new roots are thrown out, which are adapted to the altered situation of the plant, and then the growth proceeds in the usual manner. The reverse experiment would seem to confirm this view. If a seedling that has grown for a short time only in the soil, so that its roots are but twice or thrice branch- ed, have these immersed in water, the roots already form- ed mostly or entirely perish in a short time. They indeed absorb water, and the plant is sustained by them, but im- mediately new roots grow from the crown with great ra- pidity, and tike the place of the original roots, which become disorganized and useless. It is, however, only the young and active rootlets, and those covered with hairs, which thus refuse to live in water. The older parts of the roots, which are destitute of fibrils and which have nearly ceased to be active in the work of absorption, are not af- fected by the change of circumstance. These facts, which are due to the researches of Dr. Sachs, ( Vs. Sé., 2, p. 135) would naturally lead to the conclusion that the absorbent surface of the root undergoes some structural change, or produces new roots with modified characters, in order to adapt itself to the medium in which it is placed. It would appear that when this adaptation proceeds rapidly, the plant is not permanently retarded in its growth by a gradual change in the character of the medium which surrounds its roots, as may happen in case of rice and marsh-plants, when the saturated soil in which they may be situated at one time, is slowly dried. Sudden changes of medium about the roots of plants slow to adapt them- selves, would be fatal to their existence. Nobbe has, however, carefully compared the roots of buckwheat, as developed in the soil, with those emitted in water, without being able to observe any structural differ eneea The facts detailed above admit of partial, if not ee en THE VEGETATIVE ORGANS OF PLANTS. 297 complete explanation, without recourse to the supposition that soil and water-roots are essentially diverse in nature. When a plant which is rooted in the soil is taken up so that the fibrils are not broken or injured, and set into wa- ter, it does not suffer any hindrance in growth, as Sachs has found by late experiments. (xperimental Physi- slogie, p. 177.) Ordinarily, the suspension of growth and decay of fibrils and rootlets is due, doubtless, to the mechanical injury they suffer in removing from the soil. Again, when a plant that has been reared in water is planted in earth, similar injury occurs in packing the soil about the roots, and moreover the fibrils cannot be brought into that close contact with the soil which is necessary for them to supply the foliage with water; hence the plant wilts, and may easily perish unless profusely yas or Sripided from evaporation. The issue of water or soil-roots, either or both, from the same plant, according to the circumstances in which it is placed, finds something analogous in reference to air- roots. As before stated, these chiefly occur on tropical plants, or in shaded, warm, and very moist situations. Schacht informs us that in the dark and humid forest ra- vines of Madeira and Teneriffe, the Laurus Canariensis, a large tree, sends out from its stem during the autumn rains, a profusion of fleshy air-roots, which cover the trunk with their interlacing branches and grow to an inch in thick- ness. The following summer, they dry away and fall to the ground, to be replaced by new ones in the ensuing au- tumn. (Der Baum, p. 172.) The formation of air-roots may be very easily observed by filling a tall vial with water to the depth of half an inch, inserting therein a branch of a common house-plant, the Tradescantia zebrina, so that the cut end of the stem shall stand in the water, and finally corking the vial air-tight, The plant, which is very tenacious of life, and usually grows well in spite of all neglect, is not checked in its vegetative development by the treatment just described, but immediately bevins to adapt itself to its new circumstances. Ina few days, if the temperature be 70° or there about, air-roots will be seen to issue from the joints of the stem. Thess 258 HOW CROPS GROW. are fringed with a profusion of delicate hairs, and rapidly extend toa iength of from one to two inches. The lower ones, if they chance to penetrate the water, become discolored and decay; the others, howevet,- vemain for a long time fresh, and of a white color. As already mentioned, Indian corn frequently produces air-roots. The same is true of the oat, of buckwheat, of the grape-vine, and of other plants of temperate re- gions when they are placed for some time in tropical con- ditions, i. e., when they grow in a rich soil and their over- ground organs are surrounded by a very warm and very moist atmosphere. It has been conjectured that these air-roots serve to ab- sorb moisture from the air and thus aid to maintain the growth of the plant. This subject has been studied by Unger, Chatin, and Duchartre. The observers first named were led to conclude that these organs do absorb water from the air. Duchartre, however, denies their absorptive power. It is probably true that they can and do absorb to some extent the water that exists as vapor in the at- mosphere. At the same time they may not usually con- dense enough to make good the loss that takes place in other parts of the plant by evaporation. Hence the re- sults of Duchartre, which were obtained on the entire plant and not on the air-roots alone. (Hléments de Botanique, p. 216.) It certainly appears improbable that organs which only develope themselves in a humid atmos- phere, where the plant can have no lack of water, should be specially charged with the office of collecting moisture from the air. Root-Excretions.—It has been supposed that the roots of plants perform a function of excretion, the reverse of absorption—that plants, like animals, reject matters which are no longer of use in their organism, and that the re- jected matters are poisonous to the kind of vegetation from which they originated. De Candolle, an eminent French botanist, who first advanced this doctrine, founded TUE VEGETATIVE ORGANS OF PLANTS. 259 it upon the observation that certain plants exude drops of liquid from their roots when these are placed in dry sand, and that odors exhale from the roots of other plants. Numerous experiments have been instituted at various times for the purpose of testing this question. The most extensive inquiries we are aware of, are those of Dr. Al fred Gyde, (Zrans. Highland and Agr. Soc., 1845-7, p. 273-92). This experimenter planted a variety of agricul- tural plants, viz., wheat, barley, oats, rye, beans, peas, vetches, cabbage, mustard, and turnips, in pots filled either with garden soil, sand, moss, or charcoal, and after they had attained considerable growth, removed the earth, etc., from their roots by washing with water, using care not to in- jure or wound them, and then immersed the roots in ves- sels of pure water. The plants were allowed to remain in these circumstances, their roots being kept in darkness, but their foliage exposed to light, from three to seventeen days. In most cases they continued apparently in a good state of health. At the expiration of the time of experi- ment, the water which had been in contact with tke roots was evaporated, and was found to leave a very minute amount of yellowish or brown matter, a portion of which was of organic and the remainder of mineral origin. Dr. Gyde concluded from his numerous trials, that plants do throw off organic and inorganic excretions similar in com- position to their sip; but that the quantity is exceedingly small, and is not injurious to the plants which furnish them. In the light of newer investigations touching the strue- ture of roots and their adaptation to the medium which happens to invest them, we may well doubt whether agri- cultural plants in the healthy state excrete any solid or liquid matters whatever from their roots. The familiar excretion of gum, resin, and sugar,* from the stems of * From the wounded bark of the Sugar Pine, (Pinus Lambertiana,) of Cali. ‘ernis- 260 HOW CROPS G&OW. trees appears to result from wounds or disease, and the matters which in the experiments of Gyde and others were observed to be communicated by the roots of plants to pure water, probably came either from the continual pushing off of the tips of the rootlets by -he interior growing point—a process always naturally accompanying the growth of roots—or from the disorganization of the absorbent root-hairs. Under certain circumstances, small quantities of mineral salts may indeed d/ffuse out of the root-cells into the water of the soil. This is, however, no physiological action, but a purely physical process. Vitality of Roots.—It appears that in case of most plants the roots cannot long continue their vitality if their connection with the leaves be interrupted, unless, indeed, they be kept at a winter temperature. Hence weeds may be effectually destroyed by cutting down their tops; al- though, in many cases, the process must be several times repeated before the result is attained. The roots of our root-crops, properly so-called, viz., beets, turnips, carrots, and parsnips, when harvested in au- tumn, contain the elements of a second year’s growth of stem, etc., in the form of a bud at the crown of the root. If the crown be cut away from the root, the latter cannot vegetate, while the growth of the crown itself is not thereby prevented. As regards internal structure, the root closely resembles the stem, and what is stated of the latter on subsequent pages, applies in all essential points to the former, § 2. THE STEM. Shortly after the protrusion of the rootlet from a ger- minating seed, the Srem makes its appearance. It has, in general, an upward direction, which in many plants is per- THE VEGETATIVE ORGANS OF PLANTS, 261 manent, while in others it shortly falls to the ground and grows thereafter horizontally. All plants of the higher orders have stems, though in many instances they do not appear above ground, but ex- tend beneath the surface of the soil, and are usually con- sidered to be roots. While the root, save in exceptional cases, does not de- velop other organs, it is the special function of the stem to bear the leaves, flowers, and seed, of the plant, and even in certain tribes of vegetation, like the cacti, which have no leaves, it performs the offices of these organs. In gen- eral, the functions of the stem are subordinate to those of the organs which it bears—the leaves and flowers. It is the support of these organs, and only extends in length or thickness with the apparent purpose of sustaining them either mechanically or nutritively. Buds.—In the seed the stem exists in a rudimentary state, associated with undeveloped leaves, forming a bud. The stem always proceeds at first from a bud, during all its growth is terminated by a hud at every growing point, and only ceases to be thus tipped when it fully accom- plishes its growth by the production of seed, or dies from injury or disease. In the leaf-bud we find a number of embryo leaves and leaf-like scales, in close contact and within each other, but all attached at the base, to a cen- tral conical axis, fig. 45. The open- ing of the bud con- sists in the lengthening of this axis, which is the stem, and the consequent separation of the leaves from each Fig. 45. 262 HOW CROPS GROW. other. If the rudimentary leaves of a bud be represented by a nest of flower-pots, the smaller placed. within the larger, the stem may be signified by a rope of India- rubber passed through the holes in the bottom of the pots. The growth of the stem may now be shown by stretch- ing the rope,whereby the pots are brought away from each other, and the whole combination is made to assuine the char- acter of a fully developed stem, bearing its leaves at regular intervals; with these important differences, that the por- tions of stem nearest the root extend more rapidly than those above them, and the stem has within it the material and the mechanism for the continual formation of new buds, which unfold in successive order. In fig. 45, which represents the two terminal buds of a lilae twig, is shown not only the external appearance of the buds, which are covered with leaf-like scales, imbricated like shingles on a roof; but, in the section, are seen the edges of the undeveloped leaves attached to the conical axis. All the leaves and the whole stem of a twig of one summer’s growth thus exist in the bud, in plan and in miniature. Subsequent growth is but the development of the plan. In the flower-bud the same structure is manifest, save that the rudimentary flowers and fruit are enclosed within the leaves, and may often be seen plainly on cutting the bud open. Culms; Nodes; Internodes.—The grasses and the com- mon cereal grains have single, unbranched stems, termed culms in botanical language. The leaves of these plants clasp the stem entirely at their base, and at this point is formed a well-defined, thickened knot or node in the stem The portions of the stem between these nodes are termed internodes, Branching Stems,—Other agricultural plants besides those just mentioned, and all the trees of temperate cli THE VEGETATIVE ORGANS OF YLANTS. 26% mates, have branching stems, originating in the following manner: As the principal or main stem elongates, so that the leaves arranged upon it separate from each other, we may find one or more side or axillary buds at the point where the base of the leaf or of the leaf-stalk unites with the stem. From these buds, in case their growth is not checked, side-stems or branches issue, which again sub- divide in the same manner into branchlets. In perennial plants, when young, or in their young shoots, it is easy to trace the nodes and internodes, or the points where the leaves are attached and the intervening spaces, even for some time after the leaves, which only endure for one year, are fallen away. The nodes are mani- fest by the enlargement of the stem, or by the scar covered with corky matter, which marks the spot where the leaf- stalk was attached. As the stem grows older these indi- cations of its early development are gradnally obliterated. In a forest where the trees are thickly crowded, the lower branches die away from want of light; the scars resulting from their removal are covered with a new growth of wood, so that the trunk finally appears as if it had always been destitute of branches, to a great height. When all the buds develop normally and in due propor- tion, the plant, thus regularly built up, has a symmetrical appearance, as frequently happens with many herbs, and also with some of the cone-bearing trees, especially the balsam-fir. Latent Buds.—Often, however, many of the buds re- main undeveloped either permanently or for a time Many of the side-buds of most of our forest and fruit trees fail entirely to grow, while others make no progress until the summer succeeding their first appearance. When the active buds are destroyed, either by frosts or by pinching off, other buds that would else remain latent, are pushed nto growth. In this way, trees whose young leaves are de- stroyed by spring frosts, cover themselves again after a 264 HOW CROPS GROW. time with foliage. In this way, too, the gardener molds a straggling, ill-shaped shrub or plant into almost any form he chooses; for by removing branches and buds where they have grown in undue proportion, he not only checks excess, but also calls forth development in the parts before suppressed, Adventitious or irregular Buds are produced from the stems as well as older roots of many plants, when they are mechanically injured during the growing season. The soft or red maple and the chestnut, when cut down, habitu- ally throw out buds and new stems from the stump, and the basket-willow is annually polled, or pollarded, to induce the growth of slender shoots from an old trunk. Elongation of Stems,—While roots extend chiefly at their extremities, we find the stem elongates equally, or nearly so, in all its contiguous parts, as is manifest from what has already been stated in illustration of its devel- opment from the bud. Besides the upright stem, there are a variety of prostrate and in part subterranean stems, which may be briefly no- ticed. Runners and Layers are stems that are sent out hori- zontally just above the soil, and coming in contact with the earth, take root, forming new plants, which may thence- forward grow independently. The gardener takes advan- tage of these stems to propagate certain plants. The strawberry furnishes the most familiar exemple of runners, while many of the young shoots of the currant fall to the ground and become layers. The runner is a somewhat peculiar stem. It issues horizontally, and usually bears but few or no leaves. The layer does not differ from an ordinary stem, except by the circumstance, often accident- al, of becoming prostrate. Many plants which usually send out no layers, are nevertheless artificially dayered by bending their stems or branches to the ground, or by ate THE VEGETATIVE ORGANS OF PLANTS. 265 taching to them a ball or pot of earth. The striking out of roots from the layer is in many cases facilitated by cut- ting half off, twisting, or otherwise wounding the stem at the point where it is buried in the soil. The ¢illering of wheat and other cereals, and of many grasses, is the spreading of the plant by layers. The first stems that appear from these plants ascend vertically, but, subsequently, other stems issue, whose growth is, for a time, nearly horizontal. They thus come in contact with the soil, and emit roots from their lower joints. From these again grow new stems and new roots in rapid suc- cession, so that a stool produced from a single kernel of winter wheat, having perfect freedom of growth, has been known to carry 50 or 60 grain-bearing culms. (Hallet, Jour. Roy. Soc. of Eiiz., 22, p. 372.) Subterranean Stems.—Of these there are three forms agriculturally interesting. They are usually thought to be roots, from the fact of existing below the surface of the soil. This circumstance is, however, quite accidental The pods of the pea-nut ripen beneath the ground—the flower-stems lengthening and penetrating the earth as soon as the blossom falls; but pea-nuts are not by any means to be confounded with roots. Root-stocks,—As before remarked, true roots are desti- tute of buds, and, we may add, of leaves. This fact dis- tinguishes them from the so-called creeping-root, which is a stem that extends just below the surface of the soil, emitting roots throughout its entire length. At intervals along these root-stocks, as they are appropriately named, scales are formed, which represent rudimentary leaves. In the axils of the scales may be traced the buds from which aérial stems proceed. Examples of the root-stock are very common. Among them we may mention the blood-root and pepper-root as abundant in the woods of the Northern and Middle States, and the quack-grass, 12 j - =, $ ‘ ; 266 HOW CROPS GROW. represented in fig. 46, which infests so many farms. Each node of the root-stock, being usually supplied with roots, and having latent buds, is ready to become an independ- ent growth the moment it is detached from its parent plant. In this way quack-grass becomes especially troub- Fig. 46. lesome to the farmer, for, within certain limits, the more he harrows the fields where it has obtained a footing, the more does it spread and multiply. Suckers.—The rose, raspberry, and cherry, are examples of plants which send out subterranean branches, analogous to the root-stock. These coming to the surface, become aérial stems, and are then termed suckers. The Tubers of most agricultural plants are fleshy en- largements of the extremities of subterranean stems. Their eyes are the points where the buds exist, usually three together, and where minute scales — rudimentary leaves—may be observed. The common potato and arti- choke are instances of tubers. Tubers serve excellently for propagation. Each eye, or bud, may become a new plant. From the quantity of starch, etc., accumulated in them, they are of great importance as food. The number of tubers produced by a potato-plant appears to be in- creased by planting originally at a considerable depth, or by “hilling up” earth around the base of the aérial stems during the early stages of its growth. THE VEGETATIVE ORGANS OF PLANTS. 267 Bulbs are the lower parts of stems, greatly thickened, the internodes being undeveloped, while the leaves—usu- ally scales or concentric coats—are in close contact with each other. The bulb is, in fact, a fleshy, permanent bud, usually in part or entirely subterranean. From its apex, the proper stem, the foliage, etc., proceed; while from its base, roots are sent out. The structural identity of the bulb with a bud is shown by the fact that the onion which furnishes the commonest example of the bulb, often bears bulblets at the top of its stem, in place of flowers. In like manner, the axillary buds of the tiger-lily are thickened and fleshy, and fall off as bulblets to the ground, where they produce new plants. STRUCTURE OF THE StemM.—The stem is so complicated in its structural composition that to discuss it fully would occupy a volume. For our immediate purposes it is, however, only necessary to notice it very concisely. The rudimentary stem, as found in the seed, or the new- formed part of the maturer stem at the growing points just below the terminal buds, consists of cellular tissue, i. e., of an aggregate of rounded and cohering cells, which rapidly multiply during the vigorous growth of the plant. In some of the lower orders of vegetation, as in mush- rooms and lichens, the stem, if any exist, always preserves a purely cellular character; but in all flowering plants the original cellular tissue of the stem, as well as of the root, is shortly penetrated by vasewlar tissue, consisting of ducts or tubes, which result from the obliteration of the hori- zontal partitions of cell-tissue, and by wood-cells, which are many times longer than wide, and the walls of which are much thickened by internal deposition. These ducts and wood-cells, together with some other forms of cells, are usually found in close connection, and are arranged in bundles, which constitute the fibers of the stem. They are always disposed lengthwise in the stem_ and branches. They are found to some extent in the soft 268 HOW CROPS GROW. est herbaceous stems, while they constitute a large share of the trunks of most shrubs and trees. From the tough- ness which they possess, and the manner in which they are woven through the original cellular tissue, they give to the stem its solidity and strength. The flowering plants of temperate climates may be di- vided into two great classes, in consequence of important and obvious differences in the structure of their stems and seeds. These are, 1, Endogenous or Monocotyledonous ;- and, 2, Heogenous or Dicotyledonous plants. As regards their stems, these two classes of plants differ in the ar- rangement of the vascular or woody tissue. Endogenous Plants are those whose stems enlarge by the formation of new wood in the interior, and not by the external growth of concentric layers. The seeds of endog- enous plants consist of a single piece—do not readily split into halves,—or, in botanical language, have but one cotyledon ; hence are called monocotyledonous. Indian corn, sugar cane, sorghum, wheat, oats, rye, barley, the onion, asparagus, and all the grasses, belong to this tribe of plants. If a stalk of maize, asparagus, or bamboo, be cut across, the bundles of ducts are seen disposed somewhat uni- formly throughout the section, though less abundantly to- wards the center. On splitting the fresh stalk lengthwise, the vascular bundles may be torn out like strings. At the nodes, where the stem branches, or where leaf-stalks are attached, the vascular bundles likewise divide and form a net-work, or plexus. In a ripe maize-stalk which is exposed to circumstances favoring decay, the soft cell-tis- sue first suffers change and often quite disappears, leaving THE VAGETAIIVE ORGANS OF PLANTS. 269 the firmer vascular bundles unaltered in form. A portion of the base of such a stalk, cut lengthwise, is represented in figure 47, where are seen the duct-fibers arranged par- allel to each other in the internodes, and curiously inter- woven and branched at the nodes, either those, 7 and 4, irom which roots issue, or that, c, which was clasped by the base of a leaf. The endogenous stem, as represented in the maize-stalk, has no well-defined bark that admits of being stripped off externally, and no separate central pith of soft cell-tissue free from vascular bundles. It, like the aérial portions of all flowering plants, is covered with a skin, or epidermis, composed usually of one or several layers of flattened cells, whose walls are thick, and far less penetrable to fluid than the delicate texture of the interior cell-tissue, The stem is denser and harder at the circumference than towards the center. This is due to the fact that the fibers are more numerous and older towards the outside of the stem. The newer fibers, as they continually form, grow in the inside of the stem, and hence the designation endog- enous, which in plain English means inside-grower. In consequence of this inner growth, the stems of most woody endogens, as the palms, after a time become so in- durated externally, that all lateral expansion ceases, and the stem increases only in height. It grows, nevertheless, internally, new fibers developing in the softer portions, until, in some cases, the tree dies because its interior is so closely packed with fibers that the formation of new ones, and the accompanying vital processes, become impossible. . In herbaceous endogens the soft stem admits the indefi- nite growth of new vascular tissue. The stems of the grasses are hollow, except at the nodes. Those of the rushes have a central pith free from vascular tissue. The Minute Structure of the Endogenous Stem is ex- hibited in the accompanying cuts, which represent highly 270 HOW CROPS GROW. magnified sections of a Vascular Bundle or fiber from the muize-stalk. As before remarked, the stem is composed of a ground-work of delicate cell-tissue, in which bundles of vascular tissue are distributed. Fig. 48 represents a cross section of one of these bundles, ¢, g, A, as well as of a portion of the surrounding cell-tissue, a, a. The latter consists of quite large cells, which, being but loosely packed together, have between them considerable inter- cellular spaces, 7. The vascular bundle itself is composed externally of narrow, thick-walled cells, of which those nearest the exterior of the stem, A, are termed bast-cells, as they correspond in character and position to the cells THE VEGETATIVE ORGANS OF PLANTS. 27] of the bast or inner bark of our common trees; those nearest the centre of the stem, ¢, are wood-cells. In the maize stem, bast and wood-cells are quite alike, and are distinguished only by their position. In other plants, they are often unlike as regards length, thickness, and pli- ability, though still, for the most part, similar in form. Among the wood-cells we observe a number of ducts, d, e, f, and between these and the bast-cells is a delicate and transparent tissue, g, which is the cambium—in which all the Seas of the bundle goes on until it is complete. On Fig. 49. either hand is seen a remarkably large duct, 6, 6, while the residue of the bundle is composed of long and rather thick-walled wood-cells. Our understanding of these parts will be greatly aided by a study of fig. 49, which represents a section made vertically through the bundle from ¢ to h, cutting the va- rious tissues and revealing more of their structure. In this the letters refer to the same parts as in the former cut: a, a, is the cell-tissue, enveloping the vascular bundle; the cells are observed to be much longer than wide, but are separated from each other at the ends as well as sides 272 HOW CROPS GROW. by an imperforate membrane. The wood and bast-cells, ¢, h, are seen to be long, narrow, thick-walled cells running obliquely to a point at either end. The wood-cells of oak, hickory, and the toughest woods, as well as the bast-cells of flax and hemp, are quite similar in form and appearance, The proper ducts of the stem are next in the order of our section. Of these there are several varieties, as ring-ducts, d; spiral ducts, e ; dotted ducts, f. These are continuous tubes produced by the resorption of the transverse mem- branes that once divided them into such cells as a, a, aud they are thickened internally by ring-like, spiral, or punce- tate depositions of cellulose, (see fig. 32, p. 227.) Wood- cells that consist exclusively of cellulose are pliant and elastic. It is the deposition of lignin in their walls which renders them stiff and brittle. At g. the cambium tissue is observed to consist of deli- cate cylindrical cells. Among these, partial resorption of the separating membrane often occurs, so that they com- municate directly with each other through sieve-like parti- tions, and become continuous channels or ducts, (sieve-cells, p. 280.) The cambium is the seat of growth by cell-formation. Accordingly, when a vascular bundle has attained maturi- ty, it no longer possesses a cambium; the latter has grown away from it, has reproduced itself in originating a new vascular bundle, which, in case of the endogens, branches off from the present bundle, and with exogens, runs paral- lel with, and exterior to the latter. To complete our view of the vascular bundle, fig. 50 represents a vertical section made at right angles to the last, cutting two large ducts, 0,6, a, a, is cell-tissue; ¢ c, are bast or wood-cells less thickened by interior deposi tion than those of fig. 49; d, is a ring and spiral duct; 6, b, are large dotted ducts, which exhibit at g, g, the places where they were once crossed by the double membrane ecmposing the ends of two adhering cells, by whose ab- THE VEGETATIVE ORGANS OF PLANTS. 273 sorption and removal an uninterrupted tube has been formed. In these large dotted ducts there appears to be no direct communication with the surrounding cells through their sides. The dots or pits are simply very thin points in the cell-wall, through which sap may soak ot diffuse laterally, but not flow. When the cells become mature and cease growth, the pits often become pores by l 20008 (\ 90 £00000 o Joo-* 9000000%% | 000005 Qo v0 WHYAHHD gHOTD Ve SSX rill absorption of the membrane, so that the ducts thus enter into direct communication with each other. Exogenous plants are those whose stems continually enlarge in diameter by the formation of new tissue near the outside of the stem. They are outside-growers. Their seeds are usually made up of two loosely united parts, or cotyledons, wherefore they are designated dicotyledonous. All the forest trees of temperate climates, and, among agricultural plants, the bean, pea, clover, potato, beet, tur- nip, flax, etc., are exogens. In the exogenous stem the bundles of ducts and fibers that appear in the cell-tissue are always formed just within 12* 274 HOW CROPS GROW. the epidermis. They occur at first separately, as in the endogens, but instead of being scattered throughout the cell-tissue, are disposed in a circle. As they grow, they usually close up to a ring or zone of wood, which, within, incloses unaltered cell-tissue—the pith—and without, in shrubs and trees, is covered by rind. As the stem enlarges, new rings of fibers may be form- ed, but always outside of the older ones. In hard stems of slow growth the rings are close together and chiefly consist of very firm wood-cells. In the soft stems of herbs the cell-tissue preponderates, and the ducts and cells of the vascular zones are delicate. The hardening of herba- ceous stems which takes place as they become mature, is due to the increase and induration of the wood-cells and ducts. The circular disposition of the fibers in the exogenous stem may be readily seen in a multitude of common plants. The potato tuber is a form of stem always accessible for observation. If a potato be cut across near the stem- end with a sharp knife, it is usually easy to identify upon the section a ring of vascular tissue, the general course of which is parallel to the circumference of the tuber except where it runs out to the surface in the eyes or buds, and in the narrow stem at whose extremity it grows. Ifa slice across a potato be soaked in solution of iodine for a few minutes, the vascular rings become strikingly apparent. In its active cambial cells, albuminoids are abundant, which assume a yellow tinge with iodine. The starch of the cell tissue, on the other hand, becomes intensely blue, making the vascular tissue all the more evident. Since the structure of the root is quite similar to that of the stem, a section of the common beet as well as one of a branch from any tree of temperate latitudes may serve to illustrate the concentric arrangement of the vascular zones when they are multiplied in number. THE VEGETATIVE ORGANS OF PLANTS. 275 Pith is the cell-tissue of the center of the stem. In young stems it is charged with juices; in older ones it often becomes dead and sapless. In many cases, especially when growth is active, it becomes broken and nearly obliterated, leaving a hollow stem, as in a rank pea-vine, or clover- stalk, or in a hollow potato. In the potato tuber the pith- cells are occupied throughout with starch, although, as the coloration by iodine makes evident, the quantity of starch diminishes from the vascular zone towards the center of the tuber. The Rind, which, at first, consists of mere epidermis, or short, thick-walled cells, overlying soft cellular tissue, becomes penetrated with cells of unusual length and te- nacity, which, from their position in the plant, are often termed bast-cells. These, together with ducts of various kinds, all united firmly by their sides, constitute the so- called bast-fibers, which grow chiefly upon the interior of the rind, in close proximity to the wood. With their abundant development and with age, the rind becomes bark as it occurs on shrubs and trees. The bast-cells give to the bark its peculiar toughness, and cause it to come off the stem in long and pliant strips. Bast-mats are made by weaving together strips of the inner bark of the Linden (bass or bast-wood) tree; and all the textile materials employed in making cloth and cord- age, with the exception of cotton, as flax,hemp, New Zea- land flax, etc., are bast-fibers. The leather-wood or moose- wood bark often employed for tying flour-bags, has bast- fibers of extraordinary tenacity. The external rind, like the interior pith, becomes sapless and dead in perennial plants, and after a longer or shorter period falls away. The outer bark of the grape separates in long shreds a year or two after its formation. On most forest trees the bark remains for several or many years, The expansion ef the tree furrows the bark with numerous a ee 276 HOW CROPS GROW. and deep longitudinal rifts, and it gradually decays or drops away exteriorly as the newer bark forms within. Cork is one form which the epidermal cells assume on the stem of the cork oak, on the potato tuber, and many other plants. Pith Rays.— Those portions of the first-formed cell- tissue which were interposed between the young and orig- inally ununited wood-fibers remain, and connect the pith with the rind. In hard stems they become flattened by the pressure of the fibers, and are readily seen in most kinds of wood when split lengthwise. They are especially conspicuous in the oak WS ea SS DOSS WN WN | p) Z| and maple, and form what is com- mull yy i] monly known as the silver-grain, WY The botanist terms them pith-rays Y | or medullary rays. y Fig. 51 exhibits a section of a lie y Li bit of wood of the Red Pine, Wy, y (Pinus picea,) magnified 200 di- y ameters. The section is made Y tangential to the stem and length- Z wise of the wood-cells, four of at which are in part represented, h ; it cuts across the pith-rays, whose veri-structure and position in the wood are seen at m, n. Cambium of Exogens.—The growing part of the exog- g:ous stem is thus found between the wood and the bark, or rather between the fully formed wood and the mature bark. There is, in fact, no definite limit where wood ceases and bark begins, for they are connected by the cambial or formative tissue, from which, on the one hand, wood-fibers, and on the other, bast-fibers, or the tissues of the bark, rapidly develope. In the cambium, likewise, the pith-rays THE VEGETATIVE ORGANS OF PLANTS. Papel which connect the inner and outer parts of the stem, con- tinue their outward growth. In spring-time the new cells that form in the cambial region are very delicate and easily broken. For this rea- son the rind or bark may be stripped from the wood with- out difficulty. In autumn these cells become thickened and indurated, become, in fact, full-grown bast and wood- cells, so that to peel the bark off smoothly is impossible. Minute Structure of Exogenous Stems.—The accom- panying figure (52) will serve to convey an idea of the mi- nute structure of the elements of the exogenous stem. It exhibits a highly magnified section lengthwise, through a young potato tuber. A, 6,is the rind; e,is the vascular ring; jf, the pith. The outer cells of the rind are convert- ed into cork. They have become empty of sap and are nearly impervious to air and moisture. This corky-layer, a,* constitutes the thin coat or skin that may be so readily peeled off from a boiled potato. Whenever a potato is superficially wounded, even in winter time, the exposed part heals over by the formation of cork-cells. The cell- tissue of the rind consists at its center, b, of full-formed cells with delicate membranes which contain numerous and large starch grains. On either hand, as the rind ap- * The bracket, @, is much too long, and d is correspondingly too short in the cut. 278 HOW CROPS GROW. proaches the corky-layer or the vascular ring, the cells are smaller, and contain smaller starch grains; either side of these are noticed cells containing no starch, but having nuclei, c, y. These nucleated cells are capable of multi- plication, and they are situated where the growth of the tuber takes place. The rind, which makes a large part of the flesh of the potato, increases in thickness by the formation of new cells within and with- out. Without, where it joins the corky skin, the latter likewise grows. Within, contiguous to the vascular zone, new ducts are formed. In a similar manner, the pith expands by formation of new cells, where it joins the vascular tissue, The latter consists, in our figure, of ring, spiral, and dotted ducts, like those al- ready described as occurring in the maize-stalk. The delicate cambial cells, c, are in the region of most active growth. At this point new cells rap- idly develope, those to the right, in the figure, remaining plain cells and becom- ing loosely filled with starch; those to the left developing new ducts. In the slender, overground potato- stem, as in all the stems of most agricul- tural plants, the same relation of parts is to be observed, although the vascular and woody tissues often preponderate. Wood-cells are especially abundant in those stems that need strength for the fulfilment of their offices, and in them, especially in those of our trees, the structure is commonly more complicated. Perforation of Wood-Cells in the Conifers.—In the wood of cone-bearing trees there are no proper ducts, such Fig. 53. THE VEGETATIVE ORGANS OF PLANTS. 279 as have been described. To answer the purpose of air and sap-channels, the wood-cells which constitute the con- centric rings of the old wood are constructed in a special manner, being provided laterally with visible pores, through which the contents of one cell may pass directly into those of its neighbors. Fig 53, B, represents a por- tion of an isolated wood- cell of the Scotch Fir, (Pinus sylvestris,) mag- nified 200 diameters. Upon it are seen nearly circular disks, x, y, the structure of which, while the cell is young, is shown by a section through them length- wise. A exhibits such a section through the thickened walls of two contiguous and adhering cells. w, in both A and B, shows a cavity be- tween the two primary cell-walls; y is the nar- row part of the chan- nel, that remains while the membrane thickens around it. This is seen in B, y, a8 a pore or opening in the cell. In a A it appears closed because the section passes a little to one side of the pore. In the next figure, (54,) representing a transverse sec- tion of the spring wood of the same tree magnified 300 diameters, the structure and the gradual formation of 280 HOW CROPS GROW. these pore disks is made evident. The sevtion, likewise, gives an instructive illustration of the general character of the simplest kind of wood. R, are the young cells of the rind; C, is the cambium, where cell multiplication goes on; W, is the wood, whose cells are more developed the older they are, i. e., the more distant from the cam- bium, as is seen from their figure and the thickness of their walls. At @ is shown the disk in its earliest stage; 6 and ¢ exhibit it in a more advanced growth before it be- comes a pore, the original cell-wall being still in place. At d, in the finished wood-cells, the disk has become a pore, the primary membrane has been absorbed, and a free channel made between the two cells. The dotted lines at d lead out laterally to two concentric circles, which repre- sent the disk-pore seen flatwise, as in fig. 53. At e, the section passes through the new annual ring into the au- tumn wood of the preceding year. Sieve-cells or sieve-ducts.—The spiral, ring, and dotted ducts and porous wood-cells already noticed, appear only in the older parts of the vascular bundles, and although they are occupied with sap at times whe: the stem is sur- charged with water, they are ordinarily filled with air alone. The real transmission of the nutritive juices of the growing plant, so far as it goes on through actual tubes, is “now admitted to proceed in an independent set of ducts, the so-called sieve-cells, which are usually near to, and originate from the cambium, ‘These are extremely deli- cate, elongated cells, whose transverse or lateral walls are perforated, sieve-fashion, (by absorption of the original membrane,) so as to establish direct communication from one to another, and this occurs while they are yet charged with juices and at a time when the other ducts are occu- pied with air alone. These sieve-ducts are believed to be the channels through which the matters organized in the foliage most abundantly pass in their downward move- ment to nourish the stem and root. Fig. 55 represents rs THE VEGETATIVE ORGANS OF PLANTS. 281 the sieve-cells in the overground stem of the potato; A, B, cross-section of parts of vascular bundle—4A, exterior part towards rind; B, interior portion next to pith—a, a, cell-tissue inclosing the smaller sieve- cells, A, B, which contain sap turbid with minute gran- ules; 6, cambium cells; ¢, wood-cells (which are absent in the potato tuber ;) d, ducts intermingled with wood-cells. C represents a section lengthwise of the sieve-ducts; and D, more highly magni- fied exhibits the fine- ly perforated, trans- verse partitions, through which the liquid contents free- ly pass. Milk Ducts.—Be- g * sides the ducts al- ready described, there is, in many plants, a system of irregularly branched channels containing So > | or & he VASE [Vana eee 2 9 ADA wen aE EBay 2lr A eg RRE<-o 6, shor ae PLN ONE G0 i PLEO Fey salle a Fig. 55. a milky juice, as in the sweet potato, dandelion, milk- weed, etc. These milk-ducts, together with many other details of stem-structure, are imperfectly understood, and require no further notice in this treatise. Herbaceous Stems.—Annual stems of the exogenous 282 HOW CROPS GROW. kind, whose growth is entirely arrested by winter, consist usually of a single ring of woody tissue with interior pith and surrounding bark. Often, however, the zone of wood is thin, and possesses but little solidity, while the chief part of the stem is made up of cell-tissue, so that the stem is herbaceous. Woody Stems.—Perennial exogenous stems consist, in temperate climates, of a series of rings or zones, corre- sponding in number with that of the years during which their growth has been progressing. The stems of our shrubs and trees, especially after the first few years of growth, consist, for the most part, of woody tissue, the pro- portion of cell-tissue being very small. The annual cessation of growth which occurs at the approach of winter, is marked by the formation of smaller or finer wood-cells, as shown in fig. 54, while the vigorous renewal of activity in the cambium at spring-time is ex- hibited by the growth of larger cells, and in many kinds of wood in the production of ducts, which, as in the oak, are visible to the eye at the interior of the annual layers. Sap-wood and Heart-wood,—The living processes in perennial stems, while proceeding with most force in the cambium, are not confined to that locality, but go on toa considerable depth in the wood. Except at the cambial layer, however, these processes consist not in the forma- tion of new cells, nor the enlargement of those once form- ed—not properly in growth—but in the transmission of sap and the deposition of organized matter on the interior of the wood-cells. In consequence of this deposition the inner or heart-wood of many of our forest trees becomes much denser in texture and more durable for industrial purposes. It thea acquires a color different from the outer or sap-wood (alburnum,) becomes brown in most cases, though it is yellow in the barberry and red in the red cedar, _ THE VEGETATIVE ORGANS Of PLANTS. 283 The final result of the filling up of the cells of the heart- wood s to make this part of the stem almost or quite im- passable to sap, so that the interior wood may be removed _ by decay without disturbing the vigor of the tree. Passage of Sap through the Stem.—The stem, besides supporting the foliage, flowers, and fruit, has also a most important office in admitting the passage upward to these organs, of the water and mineral matters which enter the plant by the roots. Similarly, it allows the downward ' transfer to the roots, of substances gathered by the foliage from the atmosphere. To this and other topics connected with the ascent and descent of the sap we shall hereafter recur, The stem constitutes the chief part by weight of many plants, especially of forest trees, and serves the most im- portant uses in agriculture, as well as in a thousand other industries. § 3. LEAVES. These most important organs issue from the stem, are at first folded curiously together in the bud, and after- wards expand so as to present a great amount of surface to the air and light. The leaf consists of a thin membrane of cell-tissue, ar- ranged upon a skeleton or net-work of fibers and ducts, It is directly connected with, and apparently proceeds from, the cambial-layer of the stem, of which it may, ac cordingly, be considered an expansion. In certain plants, as the cactus (prickly pear), there scarcely exist any leaves, or, if any occur, they do not differ, except in external form, from the stems. Many of these plants, above ground are in form, all stem, while in structure and function, they are all leaf 284 HOW CROPS GROW. In the grasses, although the stem and leaf are distinguish able in shape, they are but little unlike in other external characters. In forest trees, we find the most obvious and striking differences between the stem and leaves. Green Color of Leaves.—A peculiarity most character- istic of the leaf, so long as it is in vigorous discharge of its proper vegetative activities, is the possession of a green color. This color is also proper in most cases to the young bark of the stem, a fact further indicating the connection between these parts, or rather demonstrating their identity of origin and function, for it is true, not only in the case of the cactuses, but also in that of all other young plants, that the green (young) stems perform, to some extent, the same offices as the leaves. : The loss of green color that occurs in autumn, in case of the foliage of our deciduous trees, or on the maturing of the plant in case of the cereal grains, is connected with the cessation of growth and death of the leaf. There are plants whose foliage has a red, brown, white, or other than agreen color during the period of active growth. Many of these are cultivated by florists for ornamental purposes. The cells of these color- ed leaves are by no means destitute of chlorophyll, as is shown by mi- croscopic examination, though this substance is associated with other coloring matters which mask its green tint. Structure of Leaves.—While in shape, size, modes of arrangement upon, and attachment to the stem, we find among leaves no end of diversity, there is great simplicity in the matter of their internal structure. The whole surface of the leaf, on both sides, is covered with epidermis, a coating, which, in many cases, may be readily stripped off the leaf, and consists of thick-walled cells, which are, for the most part, devoid of liquid con- tents, except when very young. (4, 4; tig. 56.) The accompanying figure (56) represents the appearance of a bit of bean-leaf as secn on a section from the upper to the lower surface and highly magnified. THE VEGETATIVE ORGANS OF PLANTS. 285 Below the upper epidermis, there often occur one or more layers of oblong cells, whose sides are in close con- tact, and which are arranged endwise, with reference to the flat of the leaf. Below these, down to the lower epi- dermis, for one-half to three-quarters of the thickness of the leaf, the cells are commonly spherical or irregular in figure and arrangement, and more loosely disposed, with numerous and large interspaces. The interspaces among the leaf-cells are occupied with air, which is also, in most cases, the only con- tent of the epidermal cells. The active cells of the leaf contain some or all of the various proximate principles which have been already noticed, and in addition the coloring matter of vegetation, —the so-called chlorophyll, or leaf-green, p. 109. Under the microscope, this sub- stance is commonly seen in the form of minute grains attached to the walls of the cells, as in fig. 56, or coating starch granules, or else floating free in the cell-sap. The structure of the veins or ribs of the leaf is similar to that of the vascular bundles or fibers of the stem, of which they are branches. At a, fig. 56, is seen the cross section of a vein in the bean-leaf. The epidermis, while often smooth, is frequently beset with hairs or glands, as seen in the figure. These are va- riously shaped cells, sometimes empty, sometimes, as in the nettle, filled with an acid liquid. Their office is little understood. Leaf-Pores.—The epidermis is further provided with a vast number of curious “ breathing pores,” or stomata, by means of which the intercellular spaces in the interior of the leaf may be brought into direct communication with the outer atmosphere. Each of these stomata consists 286 HOW CROPS GROW. usually of two curved cells, which are disposed toward each other nearly like the two sides of the letter O, or like the halves of an elliptical carriage-spring, (figs. 52 and 53). The opening between them is an actual orifice in the the orifice is, however, con- stantly changing, as the at- mosphere becomes drier or more moist, and as the sun- light acts more or less in- tensely on its surface. In moist air, they curve out- wards, and the aperture is enlarged; in dry air, they straighten and shut together like the springs of a heavily loaded carriage, and nearly or entirely close the entrance. The effect of strong light is to enlarge their orifices. In fig. 56 is represented a section through the shorter diameter of a pore on the under surface of a bean-leaf. The air-space within it is shaded black. Unlike the other epidermal cells, those of the leaf-pore contain grains of chlorophyll. Fig. 57 represents a portion of the epidermis of the upper surface of a potato-leaf, and fig. 58 a similar portion of the under surface of the same leaf, magnified 200 diameters. In both figures are seen the open pores between the semi-elliptical cells. The outline of the other epidermal cells is marked by irregular double lines. The round bodies in the cells of the pores are starch-grains, often present in these cells, when not existing in any other part of the leaf. . The stomata are with few ex- ceptions altogether wanting on the submerged leaves of aquatic plants. On floating leaves they occur, but only on the upper surface, Thus, as a rule, they are not found in contact with liquid water. On the other hand, they are either absent from, or comparatively few in Fig. 58, skin of the leaf. The size of THE VEGETATIVE ORGANS OF PLANTS. 287 number upon, the upper surfaces of land plants, which are exposed to the heat of the sun, while they exist in great numbers on the lower sides of all green leaves. In number and size, they vary remarkably. Some leaves possess but 800 to the square inch, while others have as many as 170,000 to that amount of surface. About 100,000 may be counted on an average-sized apple-leaf. In general, they are largest and most numerous on plants which be- long in damp and shaded situations, and then exist on both sides of the leaf. The epidermis itself is most dense—consists of thick: walled cells and several layers of them—in case of leaves which belong to the vegetation of sandy soils in hot cli- mates. Often it is impregnated with wax on its upper surface, and is thereby made almost impenetrable to moist- ure. On the other hand, in rapidly growing plants adapt- ed to moist situations, the epidermis is thin and delicate. Exhalation of Water-Vapor.—A considerable loss of water goes on from the leaves of growing plants when they are freely exposed to the atmosphere. The water thus lost exhales in the form of invisible vapor. The quantity of water exhaled from any plant may be easily ascertained, provided it is growing in a pot of glazed earthen, or other impervious material. A metal or glass cover is cemented air-tight to the rim of the vessel, and around the stem of the plant. The cover has an opening with a cork, through which weighed quantities of water are added from time to time, as required. The amount of exhalation during any given interval of time is learned with a close approach to accuracy by simply noting the loss of weight which the plant and pot together suffer. Hales, who first experimented in this manner, found that a sunflower, whose foliage had an aggregate surface of 39 square feet, gave off 3 lbs. of water in a space of 24 Lours. Knop observed a maize-plant to exhale, between 288 HOW CROPS GROW. May 22d and September 4th, no less than 36 times its weight of water. Exhalation is not a regular or uniform process, but varies with a number of circumstances and conditions. It de- pends largely upon the dryness and temperature of the air. When the air is in the state most favorable to evaporation, the loss from the plant is rapid and large. When the air is saturated with moisture, as during dewy nights or rainy weather, then exhalation is nearly or totally checked. The temperature of the soil, and even its chemical com- position, the condition of the leaf as to its age, texture, and number of stomata, likewise affect the rate of exe halation. Exhalation is a process not necessary to the life of the plant, since it may be suppressed or be reduced to a minimum, as ina Wardian case or fernery, without evident influence on growth. Neither is it detrimental, unless the loss is greater than the supply. If water escapes from the leaves faster than it enters the roots, the plant wilts; and if this disturbance goes on too far, it dies. Exhalation ordinarily proceeds to a large extent from the surface of the epidermal cells. Although the cavities of these cells are chiefly occupied with air, their thickened walls transmit outward the water which is supplied to the interior of the leaf through the cambial ducts. Other- wise the escape of vapor occurs through the stomata. These pores appear to have the function of regulating the exhala tion, to a great extent, by their property of closing, when the air, from its dryness, favors rapid evaporation. They are, in fact, self-acting valves which protect the plant from teo sudden and rapid loss of water, Access of Air to the Interior of the Plant.—Not only does the leaf allow the escape of vapor of water, but it admits of the entrance and exit of gaseous bodies. THE VEGETATIVE ORGANS OF PLANTS. 289 The particles of atmospheric air have easy access to the interior of all leaves, however dense and close their epi- dermis may be, however few or small their stomata. All leaves are actively engaged in absorbing and exhaling cer- tain gaseous ingredients of the atmosphere during the whole of their healthy existence. The entire plant is, in fact, pervious to air through the stomata of the leaves. These com- municate with the intercellular spaces of the leaf, which are, in general, occupied exclusively with air, and these again connect with the ducts which ramify throughout the veins of the leaf and branch from the vascular bundles of the stem. In the bark or epidermis of woody stems, as Hales long ago discovered, pores or cracks exist, through which the air has communi- cation with the longitudinal ducts. These facts admit of demonstration by simple means. Sachs employs for this pur- pose an apparatus consisting of a short wide tube of glass, B, fig. 59, to which is adapted, below, by a tightly fitting cork, a bent glass tube. The stem of a leaf is passed through a cork which is then secured air-tight in the other opening of the wide tube, the leaf itself being included in the latter, and the joints are made air-tight by smearing with tallow. The whole is then placed in a glass jar con- taining enough water to cover the projecting leaf-stem, and mercury is quickly poured into the open end of the bent tube, soas nearly to fill the latter. The pressure of the column of this dense liquid immediately forces air into the stomata of the leaf, and a corresponding quantity is forced on through the interecllular spaces and through the vein ducts into the ducts of the leaf-stem, whence it issues in fine bubbles at S. It is even easy in many eases to demonstrate the permeability of the leaf to air by immersing it in water, and, taking the leaf-stem between the lips, produce a current by blowing. In this case the air escapes from the stomata. ‘The air passages of the stem may be shown by a similar arrangement, 13 290 HOW CROPS GROW. or in many instances, as, for example, with a stalk of maize, by simply immersing one end in water and blowing into the other. On the contrary, roots are destitute of any visible pores, and are not pervious to external air or vapor in the sense that leaves and young stems are. The air passages in the plant correspond roughly to the mouth, throat, and breathing cavities of the animal. We have, as yet, merely noticed the direct communication of these passages with the external air by means of micros- copically visible openings. But the cells which are not visibly porous readily allow the access and egress of wa- ter and of gases by osmose. To the mode in which this is effected we shall recur on subsequent pages, (pp. 354 - 366.) The Offices of Foliage are to put the plant in commu- nication with the atmosphere and with the sun. On the one hand it permits, and to a certain degree regulates, the escape of the water which is continually pumped into the plant by its roots, and on the other hand it absorbs from the air, which freely penetrates it, certain gases whicb furnish the principal materials for the organization of vege- table matter. We have seen that the plant consists of elements, some of which are volatile at the heat of ordina ry fires, while others are fixed at this temperature. When a plant is burned, the former, to the extent of 90-99 per cent of the plant, are converted into gases, the latter re- main as ashes. The reconstructicn of vegetation from the products of its combustion (or decay) is, in its simplest phase, the gathering by a new plant of the ashes from the soil through its roots, and of these gases from the air by its leaves, and the compounding of these comparatively sim- ple substances into the highly complex ingredients of the vegetable organism. Of this work the leaves have by far the larger share to perform; hence the extent of their sur- face and their indispensability to the welfare of the plant REPRODUCTIVE ORGANS O¥ PLANTS. 29] The assimilation of carbon in the plant is most inti- mately connected with the chlorophyll, which has been no- ticed as the green coloring matter of the leaf, and depends also upon the solar rays. CHAPTER IV. REPRODUCTIVE ORGANS OF PLANTS. § 1. THE FLOWER. The onward growth of the stem or of its branches is not necessarily limited, until from the terminal buds, in- stead of leaves, only FLowers unfold. When this happens, as is the case with most annual and biennial plants, raised on the farm or in the garden, the vegetative energy has usu- ally attained its fullest development, and the reproductive function begins to prepare for the death of the individual by providing seeds which shall perpetuate the species. There is often at first no apparent difference between the leaf-buds and flower-buds, but commonly in the later stages of their growth, the latter are to be readily dis- tinguished from the former by their greater size, and by peculiar shape or color. The Flower is a short branch, bearing a collection of organs, which, though usually having little resemblance to foliage, may be considered as leaves, more or less mod- ified in form, color, and office. The flower commonly presents four different sets of or- gans, viz, Calyx, Corolla, Stamens, and Pistils, and is then said to be complete, as in case of the apple, potato 292 HOW CROPS GROW. and many common plants. Fig. 60 represents the com- plete flower of the Fuchsia, or ladies’ ear-drop, now uni- versally cultivated. In fig. 61 the same is shown in section. The Calyx, (cup,) cv, is the outermost floral envelope. Its color is red or white in the Fuchsia, though generally it is green, When it consists of several distinct leaves, they are called sepals. The calyx is frequently small and inconspicuous. In some cases it falls away as the flower opens. In the Fuchsia it firm- ly adheres at its base to the seed- vessel, and is divid- w ed into four lobes. The Corolla, (crown,) ¢, or ca, is one or several series of leaves which are situated within the calyx. It is usually of some other than a green color, (in the Fuchsia, purple, etc.,) often has marked peculiarities of form and great delicacy of structure, and thus chiefly gives beauty to the flower. When the corolla is divided into separate leaves, these are termed petals. The Fuchsia has four petals, which are attached to the calyx-tube. Fig. 61. The Stamens, s, in fig’s 60 and 61, are generally slender, thread-like organs, terminated by an oblong sack, the @n- ther, which, when the flower attains its full growth, dis- charges a fine yellow or brown dust, the so-called pollen. REPRODUCTIVE ORGANS OF PLANTS. 295 The forms of anthers, as well as of the grains of pollen, vary with nea ly every kind of plant. The yellow pullen of pine and spruce trees is not iufrequently transported by the wind to a great distance, and when brought down by rain in considerable quantities, has been mistaken for sulphur, The Pistil, », in fig’s 60 and 61, or pistils, occupy the center of the perfect flower. They are exceedingly vas rious in form, but always have at their base the seed-ves- sels or ovaries, ov, in which are found the ovules (little eggs) or rudimentary seeds. The summit of the pistil is destitute of the epidermis which covers all other parts of the plant, and is termed the stigma, st. As has been remarked, the floral organs may be consid- ered to be modified leaves; or rather, all the appendages of the stem—the leaves and the parts of the flower to- gether—are different developments of one fundamental organ, The justness of this idea is sustained by the transforma- tions which are often observed. The rose in its natural state has a corolla consisting of five petals, but has a multitude of stamens and pistils. In a@rich soil, or as the effect of those agencies which are united in “cultivation,” nearly all the pistils and stamens lose their reproductive function and proper structure, and revert to petals; hence the flower becomes double. The tulip, poppy, and numerous garden-flowers, illustrate this interesting metamorphosis, and in these flowers we may often see at once the change in various stages intermediate between the perfect petal and the unaltered pistil. On the other hand, the reversion of all the floral organs into ordinary green leaves has been observed not infre- quently, in case of the rose, white clover, and other plants. While the complete flower consists of the four sets of organs above described, only the stamens and pistils are essential to the production of seed. The latter, accord- 294 HOW CROPS GROW. ingly, constitute a perfect flower even in the absence of calyx and coroll.. The flower of buckwheat has no corolla, but a white or pinkish calyx. The grasses h’.ve flowers in which calyx and corolla are represented by scale-like leaves, which, as the plants ma- ture, become cr aff. In varinus plants the stamens and pistils are borne in separate fowers. Such are called moncecious plants, of which the rch and oak, maize, melon, squash, cucumber, and oftea’sres the strawberry, are examples. In cas’ of maize, the staminate flowers are the “tas- sels” ot the summit of the stalk; the pistillate flowers are tre young ears, the pistils themselves being the “ silk,” each fiber of which has an ovary at its base, that, if fer- tilize1, developes to a kernel. Diecious plants are those which bear the staminate (wale, or sterile) flowers and the pistillate (female, or fer- tile) flowers on different individuals; the willow tree, the hop-vine, and hemp, are of this kind. _ Fertilization and Fructification.—The grand function of the flower is fructification. For this purpose the pollen must fall upon or be carried by wind, insects, or other agen- cies, to the naked tip of the pistil. Thus situated, each pollen-grain sends out a slender tube of microscopic diam- eter, which penetrates the interior of the pistil until it en- ters the seed-sack and comes in contact with the ovule or rudimentary seed. This contact being established, the ovule is fertilized and begins to grow. Thenceforward the corolla and stamens usually wither, while the base of the pistil and the included ovules rapidly increase in size until the seeds are ripe, when the seed-vessel falls to the ground or else opens and releases its contents. Fig. 62 exhibits the process of fertilization as observed in a plant allied to buckwheat, viz., the Polygonum cor REPRODUCTIVE ORGANS OF PLANTS. 295 volvulus. The cut represents a magnified section length- wise through the short pistil; a, is the stigma or summit of the pistil; 6, are grains of pollen; c, are pollen tubes that have penetrated into the seed- oe vessel which forms the base of the vite ? I e pistil; one has entered the mouth of the rudimentary seed, g, and reached | the embryo sack, e, within which it causes the development of a germ; d, represents the interior wall of the seed-vessel; fA, the base of the seed and its attachment to the seed-vessel. Darwin has shown that certain plants, which have pistils and stamens in the same flower, are incapable of self-fertilization, and depend upon in- sects to carry pollen to their stigmas. Such are many Orchids. Artificial Fecundation has been proposed by Hooibrenk, in Belgium, as a means of increasing the yield of certiin crops. Hooi. brenk’s plan of agitating the heads of grain at the time when the pollen is ripe, in order to ensure its distribution, which is done by two men traversing the field carrying a rope between them so as to lightly brush over the heads, appears to have been found very useful in some cases, though in many trials no good effects have followed its application. We must therefore conclude that agitation by the winds and the good offices of insects commonly render artificial assistance in the fecundating process en- tirely superfluous. Hybridizing.—As the union of the sexes of different kinds of animals sometimes results in the birth of a hybrid, so among plants, the ovules of one kind may be fertilized by the pollen of another, and the seed thus developed, in its growth, produces a hybrid plant. In both the animal v i : all " A ————_ “iat 4 Z == = == Ah ; iF =i) 1 LUTTE: i \ ‘ t y Fig. 62. SS 296 HOW CROPS GROW. and vegetable kingdoms the limits within which hybridiza tion is possible appear to be very narrow. It is only be tween closely allied species that fecundation can take place. Wheat, oats, and barley, show no tendency to “ mix”; the pollen of one of these similar plants being incapable of fertilizing the ovules of the others. In flower and fruit-culture, hybridization is practised or attempted, as a means of producing new kinds. Thus the celebrated Rogers’ Seedling Grapes are believed to be hy- brids between the European grape, Vitis vinifera, and the allied but distinct Vitis labrusea, of North America. Hybridization between plants is effected, if at all, by removing from the flower of one kind, the stamens before they shed their pollen, and dusting the summit of the pistil with pollen from another kind. The mixing of different varieties, as commonly happens among maize, melons, etc., is not properly hybridization, this word being used in the long-established sense. _We are thus led to brief notice of the meaning of the terms species and variety, and of the distinctions employed in botanical classification. Species.—The idea of species as distinct from variety which has been held by most scientific authorities hither- to, is based primarily on the faculty of continued repro- duction. The horse is a species comprising many vari- eties. Any two of these varieties by sexual union may propagate the species. The same is true of the ass. The horse and the ass by sexual union produce a hybrid—the mule,—but the sexual union of mules is without result. They cannot continue the mule as a distinct kind of ani- mal—as 1 species. Among animals a species therefore com- prises all those individuals which are related by common origin or fraternity, and which are capable of sexual fer tility. This conception involves original and permaneot _ differences between different species. REPRODUCTIVE ORGANS OF PLANTS. 29? Species, therefore, cannot change any of their essential characters, those characters which are hence termed specific. Varieties.—Individuals of the same spevies differ. In fact, no two individuals are quite alike. Circumstances of temperature, food, and habits of life, increase these differ- ences, and varieties originate when such differences assume a comparative permanence and fixity. But as external conditions cause variation away from any particular rep- resentative of a species, so they may cause variation back again to the original, and although variation may take a seemingly wide range, its bounds are fixed and do not touch specific characters. The causes that produce varieties are numerous, but in many cases their nature and their mode of action is diffi- cult or impossible to understand. The influence of scarcity or abundance of nutriment we can easily comprehend may dwarf a plant or lead to the production of a giant indi vidual; but how, in some cases, the peculiarities thus im- pressed upon individuals acquire permanence and are transmitted to subsequent generations, while in others they disappear, is beyond explanation. Among plants, varieties may often be perpetuated by the seed. This is true of our cereal and leguminous plants, which reproduce their kind with striking regulari- ty. Other plants cannot be or are not reproduced unalter- ed by the seed, but are continued in the possession of their peculiarities by cuttings, layers, and grafts. Here the in- dividual plant is in a sense divided and multiplied. The species is propagated, but not reproduced. The fact that the seeds of a potato, a grape, an apple, or pear, cannot be depended upon to reproduce the variety, may perhaps be more commonly due to unavoidable contact of pollen from other varieties, than to inability of the mother plant. to perpetuate its peculiarities. That such inability often exists, is, however, well established, and is, in general, most obvious in case of varieties that have to the greatest 13* 298 HOW CROPS GROW. degree departed from the original spevific type. Thus nature puts the same limit to variation within a species that she has established against the mixing of species. Darwin’s Hypothesis, which is now accepted by many naturalists, is to the effect that species, as above defined, do not exist, but that new kinds (so-called species) of ani mals and plants may arise by variation, and that all exist- ing animals and plants may have developed by a process of “natural selection” from one original type. Our ob- ject here is not to discuss this intricate question, but sim- ply to put the reader in possession of the meaning attach- ed to the terms currently employed in science—termes which must long continue in use and which are necessarily found in these pages.* Genus, (plural Genera.)—In the language of anti-Dar- winianism, any set of oaks that are capable of reproducing their kind by seed, but cannot mix their seed with other oaks, constitute a species. Thus, the white oak is one species, the red oak is another, the water oak is a third, the live oak a fourth, and so on, All the oaks, white, red, etc., taken together, form a group which has a series of characters in common that distinguishes them from all other trees and plants. Such a group of species is called a genus. Families or Orders, in botanical language, are groups of genera that agree in certain particulars. Thus the sev- eral plants well-known as mallows, hollyhock, okra, and cotton, are representatives of as many different genera. They all agree in a number of points, especially as regards the structure of their fruit. They are accordingly group- ed together into a natural family or order, which differs from all others. Classes, Series, and Classification.— Classes are groups * For a masterly statement of the facts and evidence bearing on these points, which are of the greatest importance to the agriculturist, see Darwin’s worka “On the Origin of Species,” and ‘‘On the Variation of Animals and Plants ander Domestication.”* } REPRODUCTIVE ORGANS OF PLANTS. 299 ot orders, and Series are groups of classes. In botanical classification as now universally employed—classification after the Natural System—all plants are separated into two series, as follows: 1. Flowering Plants (Phenogams) which produce flowers and seeds with embryos, and 2. Flowerless Plants (Cryptogams) that have no proper flowers, and are reproduced hy spores whieh are in most cases single cells. This series includes Ferns, Horse-tails, Mosses, Liverworts, Lichens, Sea-weeds, Mushrooms, and Molds. The use of classification is to give precision to our no- tions and distinctions, and to facilitate the using and ac- quisition of knowledge. Series, classes, orders, genera, species, and varicties, are as valuable to the naturalist as pigeon holes are to the accountant, or shelves and draw- ers to the merchant. Botanical Nomenclature.—So, too, the Latin or Greek names which botanists employ are essential for the discrim- ination of plants, being equally received in all countries, and belonging to all languages where science has a home. They are made necessary not only by the confusion of tongues, but by confusions in each vernacular. Botanical usage requires for each plant two names, one to specify the genus, another to indicate the species. Thus all oaks are designated by the Latin word Quercus, while the red oak is Quercus rubra, the white oak is Quercus alba, the live oak is Quercus virens, etc. The designation of certain important families of plants is derived from a peculiarity in the form or arrangemert of the flower. Thus the pulse family, comprising the bean, pea, and vetch, as well as lucern and clover, are ealled Papilionaceous plants, from the resemblance of their flowers to a butterfly, (Latin, papilio). Again, the mustard family, including the radish, turnip, cabbage, wa 800 HOW CROPS GROW. ter-cress, etc., are termed Cruciferous plants, because their flowers have four petals arranged like the four arms of a cross, (Latin, cruz). The flowers of a large natural order of plants are ar- ranged side by side, often in great numbers, on the expand- ed extremity of the flower-stem. Examplesare the thistle, dandelion, sun-flower, artichoke, China-aster, ete., which, from bearing such compound heads, are called Composite plants. The Coniferous (cone-bearing) plants comprise the pines, larches, hemlocks, etc., whose flowers are arranged in conical receptacles. The flowers of the carrot, parsnip, and caraway, are ar- ranged at the extremities of stalks which radiate from a central stem like the arms of an umbrella; hence they are called Umbelliferous plants, (from umbel, Latin, for little screen). § 2. THE FRUIT Tur Frurr comprises the seed-vessel and the seed, to- gether with their various appendages. TuE SEED-VESSEL, consisting of the base of the pistil in its matured state, exhibits a great variety of forms and characters, which serve, chiefly, to define the different kinds of Fruits. Of these we shall only adduce such as are of common occurrence and belong to the farm, The Nut has a hard, leathery or bony shell, that does not open spontaneously. Examples are the acorn, cheste nut, beech-nut, and hazel-nut. The cup of the acorn and the bur of the others is a sort of fleshy calyx. The Stone-fruit or Drupe is a nut enveloped by a fleshy or leathery coating, like the peach, cherry, and plum, Ee REPRODUCTIVE ORGANS OF PLANTS. 30} also the butternut and hickory-nut. Raspberries and blackberries are clusters of small drupes. Pome is a term applied to fruits like the apple and pear, the core of which is the true seed-vessel, originally belonging to the pistil, while the often edible flesh is the enormously enlarged and thickened calyx, whose withered tips are always to be found at the end opposite the stem. The Berry is a many-seeded fruit of which the entire seed-vessel becomes thick and soft, as the grape, currant, tomato, and huckleberry. Gourd fruits have externally a hard rind, but are fleshy in the interior. The melon, squash, and cucumber, are of this kind. The Akene is a fruit containing a single seed which does not separate from its dry envelope. The so-called seeds of the composite plants, for example the sun-flower, thistle, and dandelion, are akenes. On removing the outer husk or seed-vessel we find within the true seed. Many akenes are furnished with a pappus, a downy or hairy appendage, as seen in the thistle, which enables the seed to float and be carried about in the wind. The fruit or grain of buck- wheat is akene-like. The Grains are properly fruits. Wheat and maize con- sist of the seed and the seed-vessel closely united. When these grains are ground, the bran that comes off is the seed-vessel together with the outer coatings of the seed. Barley-grain, in addition to the seed-vessel, has the petals of the flower or inner chaff, and oats have, besides these, the calyx or outer chaff adhering to the seed. Pod is the name properly applied to any dry seed-ves- sel which opens and scatters its seeds when ripe. Several kinds have received special designations; of these we need only notice one. The Legume is a pod, like that of the bean, which splits into two halves, along whose inner edges seeds are 802 HOW CROPS GROW. borne. The pulse family, or papilionaceous plants, are also termed leguminous from the form of their fruit. Tue SEED, or ripened ovule, is borne on a stalk which connects it with the seed-vessel. Through this stalk it is supplied with nutriment while growing. When matured and detached, a scar commonly indicates the point of former connection. The seed has usually two distinct coats or integuments. The outer one is often hard, and is generally smooth. In the case of cotton-seed it is covered with the valuable cot- ton fiber. The second coat is commonly thin and delicate. The Kernel lies within the integuments. In many cases it consists exclusively of the embryo, or rudimentary plant. In others it contains, besides the embryo, what has received the name of endosperm. The Endosperm forms the chief bulk of all the grains. If we cut a seed of maize in two lengthwise, we observe ex- tending from the point where it was attached to the cob the soft “chit,” 5, fig. 63, which is the embryo, to be pres- ently noticed. The remainder of the kernel, a, is endo- sperm; the latter, therefore, yields in great part the flour or meal which is so important a part of the food of man and animals. The endosperm is intended for the support of the young plant as it developes from the embryo, before it is capable of depending on the soil and atmosphere for sustenance. It is not, however, an indispensable part of the seed, and may be entirely removed from it, without thereby prevent- ing the growth of a new plant. The Embryo or Germ is the essential and most import- ant portion of the seed. It is, in fact, a ready-formed plant in miniature, and has its root, stem, leaves, and a bud, although these organs are often as undeveloped in form as they are in size. As above mentioned, the chit of the seeds of maize and REPRODUCTIVE ORGANS OF PLANTS. 303 the other grains is theembryo. Its form is with difficulty distinguishable in the dry seeds, but when they have been soaked for several days in water, it is readily removed from the accompanying endosperm, and plainly exhibits its three parts, viz., the radicle, the plumule, and the cotyledon. In fig. 63 is represented the embryo of maize. In A and B it is seen in section imbedded in the endosperm. C exhibits the detached embryo. The Radicle, r, is the rootlet of the seed-plant, or rather the point from which downward growth proceeds, from which the first true roots are produced. The Plumade, c,is the ascending axis of the plant, the central bud, out of which the stem with new leaves, flowers, etc., is developed. The Cotyledon, }, is in structure a ready-formed leaf, which clasps the plumule in the embryo, as the proper leaves clasp the stem in the mature maize-plant. The coty- ledon of maize does not, however, perform the functions of a leaf; on the contrary, it remains in the soil during the act of sprout- ing, and its contents, like those of the endosperm, are absorbed by the plumule and radicle. The leaves which appear above-ground, in the case of maize and the other grains (buckwheat excepted,) are those which in the embryo were wrapped together in the plumule, where they can be plainly distinguished by the aid of a magnifier. It will be noticed that the true grains (which have sheathing leaves and hollow jointed stems) are monocot- yledonous (one-cotyledoned) in the seed. As has been mentioned, this is characteristic of plants with Endogenous or inside-growing stems, (p. 268.) The seeds of the Hxogens (outside-growers) (p. 273) are dicotyledonous, i. e., have two cotyledons. Those of Fig. 63. 304 HOW CROPS GROW. buckwheat, flax, and tobacco, contain an endosperm. The seeds of nearly all other exogenous agricultural plants are destitute of an endosperm, and, exclusive of the coats, consist entirely of embryo. Such are the seeds of the Le- guminose, viz., the bean, pea, and clover; of the Crucif- ere, Viz., turnip, radish, and cabbage; of ordinary fruits, the apple, pear, cherry, plum, and peach; of the gourd family, viz., the pumpkin, melon and cucumber; and finally of many hard-wooded trees, viz., the oak, maple, elm, birch, and beech. We may best observe the structure of the two-cotyle- doned embryo in the garden or kidney-bean. After a bean has been soaked in warm water for several hours, the coats maybe easily removed, and the two fleshy cotyledons, ¢, c, in fig. 64, are found divided from each other save at the point where the radicle, a, is seen projecting like a blunt spur. On carefully breaking away one of the cotyledons, we get a side view of the radicle, a, and plumule,d, the former of which was partially and the latter entirely imbedded between the cotyledons. The plumule plainly ae exhibits two delicate leaves, on which the unaided eye may note the veins. These leaves are folded together along their mid-ribs, and may be opened and spread out with help of a needle. When the kidney-bean (Phaseolus) germinates, the cot- yledons are carried up into the air, where they become green and constitute the first pair of leaves of the new plant. The second puir are the tiny leaves of the plumule just described, between which is the bud, whence all the subsequent aerial organs develope in succession. In the horse-bean, (/uba), as in the pea, the cotyledons never assume the office of leaves, but remain in the soil and gradually yield a lirge share of their contents to the REPRODUCTIVE ORGANS OF PLANTS. 305 growing plant, shriveling and shrinking greatly in bulk, and finally falling away and passing into decay. § 3. VITALITY OF SEEDS AND THEIR INFLUENCE ON THE PLANTS THEY PRODUCE. Duration of Vitality.—In the mature seed when kept lrom excess of moisture, the embryo lies dormant. The duration of its vitality is very various. The seeds of the willow, it is asserted, will not grow after having once be- come dry, but must be sown when fresh; they lose their germinative power in two weeks after ripening. With regard to the duration of the vitality of the seeds of agricultural plants there is no little conflict of opinion among those who have experimented with them. The leguminous seeds appear to remain capable of germination during long periods. Girardin sproute: beans that were over a century old. It is said that Grimstone with great pains raised peas from a seed taken from a sealed vase found in the sarcophagus of an Egyptian mum- my, presented to the British Museum by Sir G. Wilkinson, and estimated to be near 3,000 years old. The seeds of wheat usually lose their power of growth after having been kept 3-7 years. Count Sternberg and others are said to have succeeded in germinating wheat taken from an Egyptian mummy, but only after soaking it in o#/, Sternberg relates that this ancient wheat mani- fested no vitality when placed in the soil under ordinary circumstances, nor even when submitted to the action of acids or other substances which gardeners sometimes em- ploy to promote sprouting. Vilmorin, from his own trials, doubts altogether the authenticity of the “ mummy wheat.” Dietrich, (Hof Jahr., 1862-3, p. 77,) experimented with seeds of wheat, rye, and a species of Bromus, which Bub HOW CROPS GROW. were 185 years old. Nearly every means reputed to favor germination was employed, but without success. After proper exposure to moisture, the place of the germ was usually found to be occupied by a slimy, putrefying liquid. The fact appears to be that the circumstances under which the seed is kept greatly influence the duration of its vitality. If seeds, when first gathered, be thoroughly dried, and then sealed up in tight vessels, or otherwise kept out of contact of the air, there is no reason why their vitality should not endure for ages. Oxygen and moisture, not to mention insects, are the agencies that . usually put a speedy limit to the duration of the germina- tive power of seeds. In agriculture it is a general rule that the newer the seed the better the results of its use. Experiments have proved that the older the seed the more numerous the failures to germinate, and the weaker the plants it pro- duces. Londet made trials in 1856~7 with seed-wheat of the years 1856, 755, ’54, and 53. The following table exhibits the results, which illustrate the statement just made. Per cent of seeds Length of leaves four days ™ _— as pa sprouted. after coming up. hundred seeds. Beed of 1853, none — ie taal Cla 51 0.4 to 0.8 inches 269 “1855, 3 Laud 365 ue 1856, 74 16 « 404 The results of similar experiments made by Haberlandt on various grains, are contained in the following table: Per cent of seeds that germinated in 1861 from the years : 1850 51 54 55 57 58 59 60 Wheat, 0 0 8 4 73 60 84 96 Rye, 0 0 0 0 0 0 48 100 Barley, 0 0 A. 0 48 33 92 89 Oats, 60 0 56 48 72 32 80 96 Maize, q nottried. %6 56 not tried. 77 100 9” KLEPRODUCTIVE ORGANS OF PLANTS. 30? Results of the Use of long-kept Seeds,—The fact that old seeds yield weak plants is taken advantage of by the florist in producing new varieties. It is said that while the one- year-old seeds of Ten-weeks Stocks yield single flowers, those which have been kept four years give mostly double flowers. In case of melons, the experience of gardeners goes to show that seeds which have been kept several, even seven years, though less certain to come up, yield plants that give the greatest returns of fruit; while plantings of new seeds run excessively to vines. Unripe Seeds,—Experiments by Lucanus prove that seeds gathered while still unripe,—when the kernel is soft and milky, or, in case of cereals, even before starch has formed, and when the juice of the kernel is like water in appearance,—are nevertheless capable of germination, espe- cially if they be allowed to dry in connection with the stem (after-ripening.) Such immature seeds, however, have less vigorous germinative power than those which are allowed to mature perfectly; when sown, many of them fail to come up, and those which do, yield comparatively weak plants at first and in poor soil give a poorer harvest than well-ripened seed. In rich soil, however, the plants which do appear from unripe seed, may, in time, become as vig- orous as any. (Lucanus, Vs. S¢., IV, p. 253.) According to Siegert, the sowing of unripe peas tends to produce earlier varieties. Liebig says: “The gardener is aware that the flat and shining seeds in the pod of the Stock Gillyflower will give tall plants with single flowers, while the shriveled seeds will furnish low plants with double flowers throughout.” Dwarfed or Light Seeds.—Dr. Miiller, as well as Hell- riegel, found that light grain sprouts quicker but yields weaker plants, and is not so sure of germinating as heavy grain. 808 HOW CROPS GROW. Baron Liebig asserts (Watural Laws of Husbandry, Am, Ed., 1863, p. 24) that “the strength and number of the roots and leaves formed in the process of germination, are, (as regards the non-nitrogenous constituents,) in di- rect proportion to the amount of starch in the seed.” Further, “poor and sickly seeds will produce stunted plants, which will again yield seeds bearing ina great measure the same character.” On the contrary, he states (on page 61 of the same book, foot note,) that “ Boussing- ault has observed that even seeds weighing two or three milligrames, (1-30th or 1-20th of a grain,) sown in an ab- solutely sterile soil, will produce plants in which all the organs are developed, but their weight, after months, does not amount to much more than that of the original seed. The plants are reduced in all dimensions; they may, how- ever, grow, flower, and even bear seed, which only requires a fertile soil to produce again a plant of he natural size.” These seeds must be diminutive, yet placed in a fertile soil they give a plant of normal dimensions. We must thence conclude that the amount of starch, gluten, e1c.—in other words the weight of a seed—is not altogether an index of the vigor of the plant that may spring from it. Schubert, whose observations on the reots of agricul- tural plants are detailed in a former chapter (p. 242,) says, as the result of much investigation—“ the vigorous devel- opment of plants depends far less upon the size and weight of the seed than upon the depth to which it is cov- ered with earth, and upon the stores of nourishment which it finds in its first period of life.” Value of seed as related to its Density.—Krom a series of experiments made at the Royal Ag. College at Ciren- cester, in 1863-4, Prof. Church concludes that the value of seed-wheat stands in a certain connection with its spe- cific gravity, ( Practice with Science, p. 107, London, 1865.) He found ;-— REPRODUCTIVE ORGANS OF PLANTS. 309 1, That seed-wheat of the greatest density produces the densest seed. 2. The seed-wheat of the greatest density yields the greatest amount of dressed corn. 3. The seed-wheat of medium density generally gives the largest number of ears, but the ears are poorer than those of the densest seed. 4, The seed-wheat of medium density generally pro- duces the largest number of fruiting plants. 5. The seed-wheats which sink in water but float ina liquid having the specific gravity 1.247, are of very low _ value, yielding, on an average, but 34.4 lbs. of dressed grain for every 100 yielded by the densest seed. The densest grains are not, according to Church, always the largest. The seeds he experimented with ranged from sp. gr. 1.354 to 1.401. 2 DIVISION » Tk LIFE OF THE PLANT. CHAPTER IL GERMINATION. Bi INTRODUCTORY. Having traced the composition of vegetation from its ultimate elements to the proximate organic compounds, and studied its structure in the simple cell as well as in the most highly developed plant, and, as far as needful, explain- ed the characters and functions of its various organs, we approach the subject of VecrTasLe Lirr and Nutrition, and are ready to inquire how the plant increases in bulk and weight and produces starch, sugar, oil, albuminoids, ete., which constitute directly or indirectly almost the entire food of animals. The beginning of the individual plant is in the seed, at the moment of fertilization by the action of a pollen tube on the contents of the embryo-sack. Each embryo whose development is thus ensured, is a plant in miniature, or rather an organism that is capable, under proper circum- stances, of unfolding into a plant. 310 GERMINATION. Sy The first process of development, wherein the young plant commences to manifest its separate life, and in which it is shaped into its proper and peculiar form, is called germination. The GENERAL Process and Conpirtions of GERMINATION are familiar to all. In agriculture and ordinary garden. ing we bury the ripe and sound seed a little way in the soil, and in a few days, it usually sprouts, provided it finds a certain degree of warmth and moisture. Let us attend somewhat in detail first to the phenomena of germination and afterward to the requirements of the awakening seed. § 2. THE PHENOMENA OF GERMINATION. The student will do well to watch with care the various stages of the act of germination, as exhibited in several species of plants. For this purpose a dozen or more seeds of each plant are sown, the smaller, one-half, the larger, one inch deep, in a box of earth or saw-dust, kept duly warm and moist, and one or two of each kind are uncovered and dissected at successive intervals of 12 hours until the process is complete. In this way it is easy to trace all the visible changes which occur as the embryo is quickened. The seeds of the kidney-bean, pea, of maize, buckwheat, and barley, may be employed. We thus observe that the seed first absorbs a large amount of moisture, in consequence of which it swells and becomes more soft. We see the germ enlarging beneath the seed coats, shortly the integuments burst and the radi- cle appears, afterward the plumule becomes manifest. In all agricultural plants the radicle buries itself in the soil. ‘The plumule ascends into the atmosphere and seeks exposure to the direct light of the sun, 312 HOW CROPS GROW. The endosperm, if the seed have one, and in many eases the cotyledons (so with the horse-bean, pea, maize, and barley), remain in the place where the seed was deposited. In other cases (kidney-bean, buckwheat, squash, radish, etc.,) the cotyledons ascend and become the first pair of leaves. The ascending plumule shortly unfolds new leaves, and if coming from the seed of a branched plant, lateral buds make their appearance. The radicle divides and subdi- vides in beginning the issue of true roots. When the plantlet ceases to derive nourishment from. the mother seed, the process is finished. S & THE CONDITIONS OF GERMINATION. As to the Conditions of Germination we have to con- sider in detail the following :— a. Temperature.—A certain range of warmth is essen- tial to the sprouting of a seed.—Gippert, who experiment- ed with numerous seeds, observed none to germinate be- low 39°. Sachs has ascertained for various agricultural seeds the extreme limits of warmth at which germination is possi- ble. The lowest temperatures range from 41° to 55°, the highest, from 102° to 116°. Below the minimum temper- ature a seed preserves its vitality, above the maximum it is killed. He finds, likewise, that the point at which the most rapid germination occurs is intermediate between these two extremes, and lies between 79° and 93°. Either elevation or reduction of temperature from these degrees retards the act of sprouting. In the following table are given the special tempera tures for six common plants, GERMINATION. 313 Lowest Highest Temperature of most Temperature. Temperature. rapid Germination. Wheat, 41° FB, 104° F 84° F. Barley, 41, 104. 84. Pea, 44.5 102. 84. Maize, 48, 115. 93. Scarlet-bean, 49. ihe 79. Squash, 54. 115. 93. For all agricultural plants cultivated in New England, a range of temperature of from 55° to 90° is adapted for healthy and speedy germination. It will be noticed in the above Table that the seeds of plants introduced into northern latitudes from tropical re- gions, as the squash, bean, and maize, require and endure higher temperatures than those native to temperate lati- tudes, like wheat and barley. The extremes given above are by no means so wide as would be found were we to experiment with other plants. It is probable that some seeds will germinate nearly at 32°, or the freezing point of water, while the cocoa-nut is said to yield seed- lings with greatest certainty when the heat of the soil is 120°. Sachs has observed that the temperature at which germination takes place materially influences the relative development of the parts, and thus the form of the seed- ling. According to this industrious experimenter, very low temperatures retard the production of new rootlets, buds, and leaves. The rootlets which are rudimentary in the embryo become, however, very long. On the other hand, very high temperatures cause the rapid formation of new roots and leaves, even before those existing in the yverm are fully unfolded. The medium and most favora- ble temperatures bring the parts of the embryo first into development, at the same time the rudiments of new or- gans are formed which are afterward to unfold. 6. Moisture.—A certain amount of moisture is indis pensable to all growth. In germination it is needful that 14 814 HOW CROPS GROW. ‘the seed should absorb water so that motion of the con. tents of the germ-cells can take place. Until the seed is more or less imbued with moisture, no signs of sprouting are manifested, and if a halfsprouted seed be allowed te dry the process of growth is effectually checked. The degree of moisture different seeds will endure or require is exceedingly various. The seeds of aquatic plants naturally germinate when immersed in water. Thea seeds of many land-plants, indeed, will quicken under wa- ter, but they germinate most healthfully when moist but not wet. Excess of water often causes the seed to rot. c. Oxygen Gas.— Free Oxygen, as contained in the air, is likewise essential. Saussure demonstrated by experi- ment that proper germination is impossible in its absence, and cannot proceed in an atmosphere of other gases. As we shall presently see, the chemical activity of oxygen appears to be the means of exciting the growth of the embryo. d. Light.—It has been taught that ight is prejudicial to germination, and that therefore seed must be covered. (Johnston’s Lectures on Ag. Chem. & Geology, 2d Eng. Ed., pp. 226 & 227). When, however, we consider that nature does not bury seeds but scatters them on the sur- face of the ground of forest and prairie, where they are, at the most, halfcovered and by no means removed from the light, we cannot accept such a doctrine. The warm and moist forests of tropical regions, which, though shaded, are by no means dark, are covered with sprouting seeds, The gardener knows that the seeds of heaths, calceolarias, and some other ornamental plants, germinate best when uncovered, and the seeds of common agricultural plants will sprout when placed on moist sand or saw-dust, with apparently no less readiness than when buried out of sight, Finally, R. Hoffmann (Jahresbericht tiber Agricultur Chem., 1864, po. 110) has found in experiments with 24 “> GERMINALION. 315 kinds of agricultural seeds that light exercises no appreci- able influence of any kind on germination. The Time required for Germination varies exceedingly according to the kind of seed. As ordinarily observed, the fresh seeds of the willow begin to sprout within 12 hours after falling to the ground. Those of clover, wheat, and other grains, germinate in three to five days. The fruits of the walnut, pine, and larch, lie four to six weeks before sprouting, while those of some species of ash, beech, and maple, are said not to germinate before the expiration of 14 or 2 years. The starchy and thin-skinned seeds quicken most readi- ly. The oily seeds are in general more slow, while such as are situated within thick and horny envelopes require the longest periods to excite growth. The time necessary for germination depends naturally upon the favorableness of other conditions. Cold and drought delay the process, when they do not check it al- together. Seeds that are buried deeply in the soil may re- main for years, preserving, but not manifesting, their vital- ity, because they are either too dry, too cold, or have not sufficient access to oxygen to set the germ in motion. To speak with precision, we should distinguish the time from planting the dry seed to the commencement of germ- ination which is marked by the rootlet becoming visible, and the period that elapses until the process is complete, i. e., until the stores of the mother-seed are exhausted, and the young plant is wholly cast upon its own resources, At 41° F. in the experiments of Haberlandt, the rootlet issued after 4 days, in the case of rye, and in 5-7 days in that of the other grains and clover. The sugar-beet, how- ever, lay at this temperature 22 days before beginning to sprout. At 51°, the time was shortened about one-half in case of the seeds just mentioned. Maize required 11, kidney: beans 8, and tobacco 31 days at this temperature, 316 HOW CROPS GROW. At 65° the grains, clover, peas, and flax, began to sprout in one to two days; maize, beans, and sugar-beet, in 3 days, and tobacco in 6 days. The time of completion varies with the temperature much more than that of beginning. It is, for example, ac- cording to Sachs, at 41- 55° for wheat and barley 40-45 days, «e 95-100° (79 ce ce ae 10-12 ce At a given temperature small seeds complete germina- tion much sooner than large ones. Thus at 55-60° the :rocess is finished with beans in 30-40 days. With maize in 30-35 days. ‘¢ wheat ‘20-25 ‘ Sy clover! 8-10) These differences are simply due to the fact that the smaller seeds have smaller stores of nutriment for the young plant, and are therefore more quickly exhausted. Proper Depth of Sowing.—The soil is usually the me dium of moisture, warmth, etc., to the seed, and it affects germination only as it influences the supply of these agencies; it is not otherwise essential to the process. The burying of seeds, when sown in the field or garden, serves to cover them away from birds and keep them from drying up. In the forest, at spring-time, we may see innumerable seeds sprouting upon the surface, or but half covered with decayed leaves. While it is the nearly universal result of experience in temperate regions that agricultural seeds germinate most surely when sown at a depth not exceeding 1-3 inches, there are circumstances under which a widely different practice 1s admissible or even essential. In the light and porous soil of the gardens of New Haven, peas may be scwn 6 to 8 inches deep without detriment, and are thereby better secured from the ravages of the domestic pigeon. The Moqui Indians, dwell‘ng upon the table lands GERMINATION. 317 of the higher Colorado, deposit the seeds of maize 12 or 14 inches below the surface. Thus sown, the piant thrives, while, if treated according to the plan usual in the United States and Europe, it might never appear above ground, The reasons for such a procedure are the follow- ing: The country is without rain and almost without dew. In summer the sanly soil is continuously parched by the sun at a temperature often exceeding 100° in the shade. It is only at the depth of a foot or more that the seed finds the moisture needful for its growth,—moisture furnished by the melting of the winter snows.* R. Hoffmann, experimenting in a light, loamy sand, upon 24 kinds of agricultural and market-garden seeds, found that all perished when buried 12 inches. When planted 10 inches deep, peas, vetches, beans, and maize, alone came up; at 8 inches there appeared, besides the above, wheat, millet, oats, barley, and colza; at 6 inches those already mentioned, together with winter colza, buckwheat, and suvat-oeets; at 4 inches of depth the above, and mustard, red and white clover, flax, horseradish, hemp, and turnips ; finally, at 8 inches, lucern also appeared. Hoffmann states that the deep-planted seeds generally sprouted most quickly, and all early differences in development disap- peared before the plants blossomed. On the other hand, Grouven, in trials with sugar-beet seed, made, most probably, in a well-manured an‘ rather heavy soil, found that sowing at a depth of 2 to 1} inches, gave the earliest and strongest plants; seeds deposite| at a depth of 2} inches required 5 days longer to come up than those planted at 2 in. It was further shown that seeds sown shallow in a fine wet clay required 4-5 days longer to come up than those placed at the same depth in the ordinary soil. Not only the character of the soil, which influences the * For these interesting facts the writer is indebted to Prof. J. 8. Newberry. 333 HOW CROPS GROW. supply of air, and warmth; but the kind of weather which determines both temperature and degree of moist- ure, have their effect upon the time of germination, and since these conditions are so variable, the rules of practice are laid down, and must be received with, a certain latitude. § 4, THE CHEMICAL PHYSIOLOGY OF GERMINATION. Tse Norrition or THE SrEpiinc.—The young plant grows at first exclusively at the expense of the seed. It may be aptly compared to the suckling animal, which, when new-born, is incapable of providing its own nourish- ment, but depends upon the milk of its mother. The Nutrition of the Seedling falls into three processes, which, though distinct in character, proceed simultaneous- ly. These are, 1, Solution of the Nutritive Matters of the Cotyledons or Endosperm ; 2, Transfer ; and 3, As- similation of the same. 1, The Act of Solution has no difficulty in case of dex- trin, gum, the sugars, albumin, and casein, The water which the seed imbibes to the extent of one-fourth to five-fourths of its weight, at once dissolves them. It is otherwise with the fats or oils, with starch and with gluten, which, as such, are nearly or altogether insol- uble in water. In the act of germination provision is made for transforming these bodies into the soluble ones above mentioned. So far as these changes have been traced, they are as follows: Solution of Kate.—Sachs has recently found that squash- seeds, which, when ripe, contain no starch, sugar, or dex- trin. but are very rich in oil (50°|,,) and albuminoids Pe GERMINATION. 319 (40°|,) suffer by germination such chemical change that the oil rapidly diminishes in quantity (nine-tenths disappears,) while at the same time starch, and, in some cases, sugar, ts formed. (Vs. St., III, p. 1.) Solution of Starch.—The starch that is thus organized from the fat of the oily seeds, or that which exists ready- formed in the farinaceous (floury) seeds, undergoes further changes, which have been previously alluded to (p. 78), whereby it is converted into substances that are soluble in water, viz., dextrin and grape or cane sugar. Solution of Albuminoids.—Finally, the insoluble al- buminoids are gradually transformed into soluble modifi- cations. Chemistry of Malt.—The preparation and properties of malt may serve to give an insight into the nature of the chemical metamorphoses that have just been indicated. The preparation is in this wise. Barley or wheat (sometimes rye) is soaked in water until the kernels are soft to the fingers; then it is drained and thrown up in heaps. The masses of soaked grain shortly dry, become heated, and in a few days the embryos send forth their radicles. The heaps are shoveled over, and spread out so as to avoid too great a rise of temperature, and when the sprouts are about half an inch in length, the germination is checked by drying. The dry mass, after removing the sprouts (radicles,) is malt, such as is used in the manufac- ture of beer. Malt thus consists of starchy seeds whose germination has been checked while in its early stages. The only prod- uct of the beginning growth—the sprouts—being remov ed, it exhibits in the residual seed the first results of the process of solution. The following figures, derived from the researches of Stein, in Dresden, ( Wilda’s Centralblatt, 1860, 2, pp. 8- 23,) exhibit the composition of 100 parts of Barley, and 320 HOW CROPS GROW. of the 92 parts of Malt, and the 24 of Sprouts which 100 parts of barley yield.* Composition of 2. ee 2% of Barley. Malt. Sprouts. ARE ae seas eas ois eidtaib ajejerste aie 2.42 2.11 0.29 Stole (eR SRaen ADS ROB acho Soe Ose 54.48 47.43 MaGerayererertobesleiemintesicispeis tie Sure 3.56 2.09 0.08 Insoluble Albuminoids.........-. 11.02 9.02 0,37 Soluble és ales loser’ Laeo 1.96 0.40 PORGTING aicteeis(ehaye se cicralsm ous tesitarsis stele 6.50 6.95 Extractive Matters (soluble in wa- 0.47 ter and destitute of nitrogen).. 0.90 3.68 Gellnloneetasaieemts\elsie tereislels cteieeiert 19.86 18.76 0.89 100 92 2.5 It is seen from the above statement that starch, fat, and insoluble albuminoids, have diminished in the malting process; while soluble albuminoids, dextrin, and other soluble non-nitrogenous matters, have somewhat increased in quantity. With exception of 3°|, of soluble “ extractive matters,” ¢ the diversities in composition between barley and malt are not striking. The properties of the two are, however, remarkably dif ferent. If malt be pulverized and stirred in warm water (155° F.) for an hour or two, the whole of the starch dis- appears, while sugar and dextrin*take its place. The former is recognized by the sweet taste of the wort, as the solution is called. On heating the wort to boiling, a quantity of albumin is coagulated, and may be separated by filtering, This comes in part from the transformation of the insoluble albuminoids of the barley, On adding * The analyses refer to the materials in the dry state. Ordinarily they con. tain from 10 to 16 per cent of water. It must not be omitted to mention that the proportions of malt and sprouts, as well as their composition, vary somewhat according to circumstances; and furthermore, the best analysea which it is pos sible to make are but approximate. + The term extractive matters is here applied to soluble substances, whose precise nature is not understood. They constitute 1 mixture which the cnemist Sa not able to analyze. ere GERMINATION. 821 to the filtered liquid its own bulk of a.cobsl, dextrin be- comes evident, being precipitated as a whitc puwder. Furthermore, if we mix 2—83 parts of starch with one of malt, we find that the whole undergoes the same change. An additional quantity of starch remains unaltered. The process of germination thus developes in the seed an agency by which the conversion of starch into soluble carbohydrates is accomplished with great rapidity. Diastase.—Payen & Persoz attribute this action to a nitrogenous substance which they term Déiastase, and which is found in the germinating seed in the vicinity of the embryo, but not in the radicles. They assert that one part of diastase is capable of transforming 2,0V0 parts of starch, first into dextrin and finally into sugar, and that malt yields ;};th of its weight of this substance. A short time previous to the investigations of Payen & Persoz (1833,) Saussure found that Mucidin,* the soluble nitrogenous body which may be extracted from gluten (p. 101,) transforms starch in the manner above described, and it is now known that any albuminoid may produce the same effect, although the rapidity of the action and the amount of effect are usually far less than that exhibit- ed by the so-called diastase. In order, however, that the albuminoids may transform starch as above described, it is doubtless necessary that they themselves enter into a state of alteration; they are in part decomposed and disappear in the process, These bodies thus altered become ferments. It must not be forgotten, however, that in all cases in which the conversion of starch into dextrin and sugar is accomplished artificially, an elevated temperature is re- quired, whereas in the natural process, as shown in the * Saussure designated this body mucin, but this term being established as the name of the characteristic ingredient of animal mucus, Ritthausen bas replaced it by mucidin. 14* 322 HOW CROPS GROW. germinating seed, the change goes on at ordinary or even low temperatures. It is generally taught that oxygen acting on the album- - inoids in presence of water and within a certain range of temperature induces the decomposition which confers on them the power in question. The necessity for oxygen in the act of germination has been thus accounted for, as needful to the solution of the starch, ete., of the cotyledons. This may be true at first, but, as we shall presently see, the chief action of oxygen is probably of another kind. How diastase or other similar substances accomplish the change in question is not certainly known. Soluble Starch.—The conversion of starch into sugar and dextrin is thus in a sense explained. This is not, how- ever, the only change of which starch is susceptible. In the bean, (Phaseolus multiflorus), Sachs (Sitz- ungsberichte der Wiener Akad., XXXVII, 57) in- forms us that tle starch of the cotyledons is dissolved, passes into the seedling, and reappears (in part, at least) as starch, without conver- sion into dextrin or sugar, as these substances do not appear in the cotyledons during any period of germina- tion, except in small quantity near the joining of the seedling. Compare p. 64, Unorganized Starch. The same authority gives the following account of the microscopic changes observed in the starch-grains themselves, as they undergo solution. The starch-grains of the bean have a narrow interior cavity, (as seen in fiz. 65, 1.) This at first becomes filled with a liquid. > Fig. 65. GERMINATION. 323 Next, the cavity appears enlarged (2,) its borders assume a corroded appearance (8, 4,) and frequently channels are seen extending to the surface (4, 5, 6.) Finally, the cavity becomes so large, and the channels so extended, that the starch-grain falls to pieces (7, 8.) Solution con- tinues on the fragments until they have completely disap peared. In this process it is most probable that the starch assumes the liquid form without loss of its proper chemi- eal characters, though it ceases to strike a blue color with iodine.* Soluble Albuminoids.—As we have seen (p. 104,) in- soluble animal fibrin and casein, by long keeping with imperfect access of air, pass into soluble bodies, and lat- terly E. Mulder has shown that diastase rapidly accom- plishes the same change. It would appear, in fact, that the conversion of a small quantity of any albuminoid into a ferment, by oxidation, is sufficient to render the whole soluble. The ferment exerts on the bodies from which it is formed, an action similar to that manifested by it to wards starch and other carbohydrates. The production of small quantities of acetic and lactic acids (the acids of vinegar and of sour milk) has been observed in germination. These acids perhaps assist in the solution of the albuminoids. Gaseous Products of Germination. — Before leaving this part of our subject, it is proper to notice some other results of germination which have been thought to belong to the process of solution. On referring to the table of the composition of malt, we find that 100 parts of dry barley yield 92 parts of malt and 24 of sprouts, leaving 54 parts unaccounted for. In the malting process 1} parts of the grain are dissolved in the water in which it is souked. The remaining 4 parts escape into the atmos- phere in the gaseous form, * According to Liebig, this blue reaction depends upon the adhesion of the fodine to the starch, and is not the result of a chemical combination. 324 HOW CROPS GROW. Of the elements that assume the gaseous condition, ca: bon does so to the greatest extent. It unites with atmos- pheric oxygen (partly with the oxygen of the seed, ac- cording to Oudemans) producing carbonic acid gas (CO,,.) Hydrogen is likewise separated, partly in union with oxygen, as water (H,O), but tu some degree in the free state. ree nitrogen appears in considerable amount, (Schulz, Jour. fiir Prukt. Chem., 87, p. 163,) while very minute quantities of Hydrogen and of Nitrogen combine to gaseous ammonia (NH,.) Heat developed in Germination. — These chemical changes, like all processes of oxidation, are accompanied with the production of heat. The elevation of tempera- ture may be imperceptible in the germination of a single seed, but it nevertheless occurs, and is doubtless of much importance in favoring the life of the young plant. The heaps of sprouting grain seen in the malt-house warm so rapidly and to such an extent, that much care is requisite to regulate the process; otherwise the malt is damaged by over-heating. 2. The Transfer of the Nutriment of the Seedling from the cotyledons or endosperm where it has undergone solution, takes place through the medium of the water which the seed absorbs so largely at first. This water fills the cells of the seed, and, dissolving their contents, carries them into the young plant as rapidly as they are required. The path of their transfer lies through the point where the embryo is attached to the cotyledons ; thence they are distributed at first chiefly downwards inte the extending radicles, after a little while both down- wards and upwards toward the extremities of the seedling, Sachs has observed that the carbohydrates (sugar and dextrin) occupy. the cellular tissue of the rind and pith, which are penetrated by numerous air-passages; while at first the albuminoids chiefly diffuse themselves through — GERMINATION, 325 the intermediate cambial tissue, which is destitute of air- passages, and are present in largest relative quantity at the extreme ends of the rootlets and of the plumule. In another chapter we shall notice at length the phenom- ena and physical laws which govern the diffusion of liq- uids into each other and through membranes similar to those which constitute the walls of the cells of plants, and there shall be able to gather some idea of the causes which set up and maintain the transfer of the materials of the seed into the infant plant. 3. Assimilation is the conversion of the transferred nutri- ment into the substance of the plant itself This process involves two stages, the first being a chemical, the second, a structural transformation. The chemical changes in the embryo are, in part, simply the reverse of those which occur in the cotyledous; viz., the soluble and structureless proximate principles are met- amorphosed into the insoluble and organized oncs of the same chemical composition. Thus, dextrin may })ass into cellulose, and the soluble albuminoids may revert in part to the insoluble condition in which they existed in the ripe seed, But many other and more intricate changes proceed in in the act of assimilation. With regard to a few of these we have some imperfect knowledge. Dr. Sachs informs us that when the embryo begins to grow, its expansion at first consists in the enlargement of the ready-formed cells. As a part elongates, the starch which it contains (or which is formed in the early stages of this extension), disappears, and sugar is found in its stead, dissolved in the juices of the cells. When the organ has attained its full size, sugar can no longer be detected; while the walls of the cells are found to have grown both in circumference and thickness, thus indicating the accumu lation of cellulose. 326 HOW CBOPS GROW. Oxygen Gas needful to Assimilation.—Traube has made some experiments, which seem to prove conclusively that tiie process of assimilation requires free oxygen to surround and to be absorbed by the growing parts of the germ. This observer found that newly-sprouted pea-seedlings continued to develope in a normal manner when the cot yledons, radicles, and lower part of the stem, were with drawn from the influence of oxygen by coating with var- nish or oil, On the other hand, when the tip of the plumule, for the length of about an inch, was coated with oil thickened with chalk, or when by any means this part of the plant was withdrawn from contact with free oxygen, the seedling ceased to grow, withered, and shortly perish- ed. Traube observed the elongation of the stem by the following expedient. A young pea-plant was fastened by the cotyledons to a rod, and the stem and rod were both graduated by deli- cate cross-lines, laid on at equal intervals, by means of a brush dipped in a mixture of oil and indigo. The growth of the stem was now manifest by the widening of the spaces between the lines; and by comparison with those on the rod, Traube remarked that no growth took place at a distance of more than 10-12 lines from the base of the terminal bud. Here, then, is a coincidence which appears to demonstrate that free oxygen must have access to a growing part, The fact is further shown by varnishing one side of the stem of a young pea. The varnished side ceases to extend, the uncoated portion continues enlarging, which results in, and is shown by, a curvature of the stem. Traube further indicates in what manner the elabora- tion of cellulose from sugar may require the codperation of oxygen and evolution of carbonic acid, as expressed by the subjoined equation. Glucose. Oxygen. Carbonic Acid. Water. Cellulose. 2(O,o Has Og) + AO = 12 (CO,) - 14(HyO) + Cig Hoo Oye a a ee FOOD AFTER GERMINATION. 327 When the act of germination is finished, which occurs as soon as the cotyledons and endosperm are exhausted of all their soluble matters, the plant begins a fully inde- pendent life. Previously, however, to being thus thrown upon its own resources, it has developed all the organs needful to collect its food from without; it has unfolded its perfect leaves into the atmosphere, and pervaded a por- tion of soil with its rootlets. During the latter stages of germination it gathers its nutriment both from the parent seed and from the exter- nal sources which afterward serve exclusively for its sup- port. Being fully provided with the apparatus of nutrition, its development suffers no check from the exhaustion of the mother seed, unless it has germinated in a sterile soil, or under other conditions adverse to vegetative life. CHAPTER IL Sit THE FOOD OF THE PLANT WHEN INDEPENDENT OF THE SEED. This subject will be sketched in this place in but the briefest outlines. To present it fully would necessitate entering into a detailed consideration of the Atmosphere and of the Soil whose relations to the Plant, those of the soil especially, are very numerous and complicated. A separate volume is therefore required for the adequate treatment of these topics. The Roots of a plant, which are in intimate contact with the soil, absorb thence the water that fills the active 328 HOW CROPS GROW. cells; they also imbibe such salts as the water of' the soil holds in solution; they likewise act directly on the soil, and dissolve substances, which are thus first made of avail to them. The compounds that the plant must derive from the soil are those which are found in its ash, since these are not volatile, and cannot, therefore, exist in the atmos- phere. The root, however, commonly takes up some other elements of its nutrition to which it has immediate access, Leaving out of view, for the present, those matters which, though found in the plant, appear to be unessential to its growth, viz., silica, soda and manganese, the roots absorb the following substances, viz. : Sulphates ] Potash. Phosphates Lime. Nitrates and i = Magnesia and Chlorides Tron. These salts enter the plant by the absorbent surfaces of the younger rootlets, and pass upwards through the active portions of the stem, to the leaves and to the new-forming buds. The Leaves, which are unfolded to the air, gather from it Carbonic Acid Gas. This compound suffers decompo- sition in the plant; its Carbon remains there, its Oxygen or an equivalent quantity, very nearly, is thrown off into the air again. The decomposition of carbonic acid takes place only by day and under the influence of the sun’s light. From the carbon thus acquired and the elements of wa- ter with the codperation of the ash-ingredients, the plant organizes the Carbohydrates. Probably glucose, perhaps dextrin or soluble starch, are the first products of this synthesis. The formation of carbohydrates appears to proceed in the chlorophyll-cells of the leaf. The Albuminoids require for their production the pres- ence of a compound of Nitrogen. The salts of DWitria FOOD AFTER GERMINATION, 329 Acid (uitrates) are commonly the chief, and may be the only supply of this element. The other proximate principles, viz. pectose, the fats, the alkaloids, and the acids, are built up from the same food-clements. In all cases the steps in the construc- tion of organic matters are unknown to us, or subjects of uncertain conjecture. The carbohydrates, albuminoids, etc., that are organized in the foliage, are not only transformed into the solid tis- sues of the leaf, but descend and diffuse to every active organ of the plant. The plant las within certain limits a power of selecting its food. The sea-weed, as has been remarked, contains more potash than soda, although the latter is 50 times more abundant than the former in the water of the ocean. Vegetation cannot, however, entirely shut out either ex- cess of nutritive matters or bodies that are of no use or even poisonous to it. The functions of the Atmosphere are essentially the same towards plants, whether growing under the condi- tions of aquzeculture, or under those of agriculture. The Soil, on the other hand, has offices which are peculiar to itself. We have seen that the roots of a plant have the power to decompose salts, e. g. nitrate of potash and chloride of ammonium (p. 170,) in order to appropriate one of their ingredients, the other being rejected. In aqueeculture, the experimenter must have a care to re- move the substance which would thus accumulate to the detriment of the plant. In agriculture, the soil, by virtue of its chemical and physical qualities, renders such reject- ed matters comparatively insoluble, and therefore innoc- uous. The Atmosphere is nearly invariable in its composition at all times and over all parts of the earth’s surface. Its power of directly feeding crops has, therefore, a natural limit, which cannot be increased by art. 530 HOW CROPS GROW. The Soil, on the other hand, is very variable in compo. sition and quality, and may be enriched and improved, or deteriorated and exhausted. From the Atmosphere the crop can derive no appreci- able quantity of those elements that are found in its Ash. In the Soil, however, from the waste of both plants and animals, may accumulate large supplies of all the elements of the Volatile part of Plants. Carbon, certainly in the form of carbonic acid, probably or possibly in the condi- tion of Humus (Vegetable Mould, Muck), may thus be put, as food, at the disposition of the plant. Nitrogen is chiefly furnished to crops by the soil. Nitrates are formed in the latter from various sources, and ammonia-salts, to- gether with certain proximate animal principles, viz., urea, guanin, tyrosin, uric acid and hippuric acid, likewise serve to supply nitrogen to vegetation and are ingredients of the best manures. It is, too, from the soil that the crop gathers all the Water it requires, which not only serves as the fluid medium of its chemical and structural metamorphoses, but likewise must be regarded as the mae terial from which it mostly appropriates the Hydrogen and Oxygen of its solid components. § 2, THE JUICES OF THE PLANT, THEIR NATURE AND MOVEMENTS. Very erroneous notions are entertained with regard to the nature and motion of sap. It is commonly taught that there are two regular and opposite currents of sap circu- lating in the plant. It is stated that the “crude sap” is taken up from the soil by the roots, ascends through the MOTION OF THE JUICES. 331 vessels (ducts) of the wood, to the leaves, there is concen- trated by evaporation, “elaborated” by the processes that go on in the foliage, and thence descends through the vessels of the inner bark, nourishing these tissues in its way down. The facts from which this theory of the sap first arose, all admit of a very different interpretation: while numerous considerations demonstrate the essential falsity of the theory itself. Flow of sap in the plant—net constant or necessary. --We speak of the Flow of Sap as if a rapid current were incessantly streaming through the plant, as the blood circulates in the arteries and veins of an animal, This is an erroneous conception. A maple in early March, without foliage, with its whole stem enveloped in a nearly impervious bark, its buds wrapped up in horny scales, and its roots surrounded by cold or frozen soil, cannot be supposed to have its sap in motion. Its juices must be nearly or absolutely at rest, and when sap runs copiously from an orifice made in the trunk, it is simply because the tissues are charged with water under pressure, which escapes at any outlet that may be opened for it. The sap is at rest until motion is caused by a perforation of the bark 1nd new wood. So, too, when a plant in early leaf is situated in an atmosphere charged with moisture, as happens on a rainy day, there is little motion of its sap, although, if wounded, inotion will e established, and water will stream more or less from all parts of the plant towards the cut. Sap does move in the plant when evaporation of water goes on from the surface of the foliage. This always hap- pens whenever the air is not saturated with vapor. When a wet cloth hung out, dries rapidly by giving up its moisture to the air, then the leaves of plants lose their water more or less readily, according to the nature of the foliage. Mr. Lawes found that in the moist climate of England 332 HOW CROPS GROW. common plants (Wheat, Barley, Beans, Peas, and Clover), exhaled during 5 months of growth, more than 200 times their (dry) weight of water. The water that thus evap- orates from the leaves is supplied by the soil, and en- tering the roots, rapidly streams upwards through the stem as long as a waste is to be supplied, but ceases when evaporation from the foliage is checked, The upward motion of sap is therefore to a great de- gree independent of the vital processes, and comparatively unessential to the welfare of the plant. E Flow of sap from the plant. “ Bleeding.’’—It is a familiar fact, that from a maple tree “tapped” in spring- time, or from a grape-vine wounded at the same season, a copious flow of sap takes place, which continues for a num- ber of weeks. The escape of liquid from the vine is com- monly termed “bleeding,” and while this rapid issue of sap is thus strikingly exhibited in comparatively few cases, bleeding appears to be a universal phenomenon, one that may occur, at least, to some degree, under certain con- ditions with every plant. The conditions under which sap flows are various, ac- cording to the character of the plant. Our perennial trees have their annual period of active growth in the warm season, and their vegetative functions are nearly suppressed during cold weather. As spring approaches the tree renews its growth, and the first evidence of change within is furnished by its bleeding when an opening is made through the bark into the young wood. |.| |2| |S Substance. ss 83/2] s/ =] s SSS gs S ss|s°/5/3/ S| § Sais 5 IS ee V.—REFUSE AND MANU! WAV AMRCOM CARES, 26 oa sacs occ be “3.4 6.5! GE MELE PY < CAR) cesarean vin) «e 2’ 2.0) 4.8] ... TaiwWalnut cake. 2.25... 2.2). 1.2} 1.6] 02 74;Cotton seed cake............ ddl), 4.0pess VI.—STRAW. Nol Winter wheatiscca. sce acaiees 12 | 4.96,11.5| 2.9) 2.6) 6.2 5.4| 2.9/66.3)... MG) WADteE TYG si otc cRain's cece sade 6 | 4.81)18.7) 3.3 3.1) sea! 4.7) 1.9)58.1 Stes WIL WGHter Spelhote. cas vincicrcess 2 | 5.56 11.2! 0.4) 0.9) 4.8) 6.3) 1.8/1.4). .. 7WSi/SuMBIeL Ly. os. .\s0s0 joe eas 8 | 5.55 23.4! ...| 2.8! 8.9] 6.5} 2.6'55.9).. . PBSESATI CY: < occisi since aisle ie nistereicjal= 17 | 5.10'21.6: 4.5] 2.4! 7.6) 4.3) 3.7/53.8)__.. SOIORIG 3.0 case. ce ete tens dteldenk 6 | 5.12 22.0} 5.3] 4.0) 8.2) 4.2) 3.5)48.7).... SIPMaIZe. oc ocee ss .» «| 1 | 5.4935.3) 1.2] 5.5'10.5] 8.1) 5.2:38.0)2..- SEP eAR re aedoate ao) eeeenlaeuss 21 | 5.%4 21.3) 5.3] 7.7,.37.9) 7.8) 5.6) 5.7) 6.1 SA Breld boas Leh es sees ese 4 | 7.12 44.4) 3.8) 7.8 23.1) 7.0] 0.2) 5.4/13.8 $4:Garden bean........0..-e00. 5 6.06 37.1) 6.0} 5.2:27.4] 7.8! 3.6] 4.7) 5.2 S5UBaCk wheats. costes seiecis ens 6 | 6.15 46.6) 2.2) 3.6/18.4.11.9) 5.3) 5.5) 7.7 SERADGiak eee ca’e ciwaion aiv'sieineure 12 | 4.58 25.6/10.3] 5.76.5) 7.0) 7.1] 6.7/12.4 aii eae soe cane 1 | 7.86 38.0. 1.3) 6.5:30.2) 3.5] 5.1/11.41 2.5 VII.—CHAFF, ETC. iS) MOLIGE eS aoriscesoo a Or nogeooe 3| 9.1] 1.8] 1.3] 1.9] 4.3) sales ROIS DE] bse axiee Jeleacc wclns > sens 9.5] 0.3: 2.5! 2.4) %.3' 2.Sitae eee CTT Py at a ai gs ee 3| 7.7/0.9, 1.310.4) 2.0 3.0/70.8).... UOT er see eat ideineisas ancien 13.1] 4.8, 2.6) 8.9! 0.3, 2.5159.9).... Fe) MRIZE CODE! hoc sc ciccieicacen os 5647.1] 1.2 4.1! 3.4) 4.4 1.9)/26.4).... 33/Flax seed hulls..... ....... 2/31.1| 4.3, 2.8,29.6| 2.8, 4.8]17.2] 6.1 LANTS, ETC. AGH Sse SAU acto aielcs ors! jamin citi 8.71/36.9| 5.1] 7.1/22.3/11.5] 5.3] 6.0| 4.0 95|Rotted flax stems Qi 9.0| 4.8} 5.4/51.4) 5.9) 3.1/13.8).. . 96|Flax fiber.......... : 3.3) 3.2] 5.4/63.6]/10.8} 2.7] 6.2: 0.4 97\Entire flax plant............ .80)34.2) 4.8} 9.0/15.5/23.0) 4.9) 2.6) 5.9 98|Entire hemp plant........... 2 | 4.60|18.3! 3.2] 9.6'43.4/11.6) 2.8] 7.6] 2.5 99 Entire Hop pianty .. els a acess 12 | 6.80)37.3) 2.2] 5.5/16.9]15.1] 2.6]15.4] 3.4 101|To Ta ee Sere AEA ONE r aace % [24.08 27.4] 3.7/10.5|87.0| 8.6] 3.9) 9.6] 4.5 IX.—LITTER. BAYS EROS oo eiaayelaleinins hoa vate wieidtacs 8 | 4.51/13.2) 5.3] 8.4/18.8) 5.1] 4.4/85.2) 2.1 103 Broom (Spartium).... ....+- 2 | 2.25 36.5) 2.5/12.4/17.1] 8.6] 3.5/10.3) 2.7 104\Fern (Aspidium).... ....-++ 5 | %.01'42.8! 4.5] 7.'7)14.0) 9.%) 5.1) 6.1/10.2 105 Scouring rush abe La 2 123.77:13.2| 0.5] 2.3)12.5) 2.0 6.3'53.8) 5.7 106 Sea-weed (Fucus). --| 8 14.39 14.5:24.0) 9.5/13.9) 3.1/24.0) 1.7)10.2 107 Beech leaves in auiumn mga 6 | 6.75' 5.2 0.6) 6.0/44.9] 4.2) 8.7/88.9) 0.4 108 Oak hd ..-| 1, 4.90: 3.5! 0.6) 4.0/48.6) 8.1] 4.4130.9).... 109 Fir % (Pinus ‘njtoenipen 1 | 1.4010.1)....| 9.9/41.4/16.4) 4.4/13.1] 4.4 110 Red pine leaves (Pinus Picea)| 1 | 5.82) 1.5)....| 2.3)15.2] 8.2) 2.8)70.1) . 111 Reed (Arundo phrag.)...{réa), 1 4.69) 8.6] 0.2) 1.2) 5.9) 2.0) 2.8)71.5). .. 112 Down prass (Psamma area-| 1 |.... |29.8) 4.0) 3.8)16.5! 7.2! 8.6)/18.5].... 118'Sedge (Carem)...... ...0.00- | 11 | 8.08 33.2 7.3] 4.2) 5.3) 6.7) 3.3/31.5) 5.6 114! Rush (Juncus)... .ccsceccee | % | 5.30 36.6 6.6) 6.4) 9.5] 6.4) 8.7)10.9/14.2 115 Bulrush (Scirpus).........065 He | 8.65; 9.7:10.3, 3.0! 7.2) 6.5) 5.6148.3)... X.—GRAINS AND SEEDS OF AGRICULTURAL PLANTS. IG WINGRT ae! tenei tha sasioprere 78 | 2.07/31.1) 3. 5112.2) 8.1]46.2) 2.4] 1.7]... TAB. 35 susie deve sean nde inaee 14 | 2.03|30-9| 1.8/0.9] 2.7147.5| 2:3] 1 Bl... RIS |BATICY: co 0ccenae Waaiotieduadiee 84 | 2.55/21.9) 2.8 oe 2.5/32.8) 2.3)27.2)..., NRBIOAIB AG. cic ve- acaceeuee teins 20 | 3.07/15 9| 8.8: 7.3! 3.8]20.7| 1.6)/46.4]... 379 APPENDIX. | Cn it ee ey tea EMM Met OO HAO OOMr COA Ie 6 ert es MAO rH ONHri om DWROrs ctl a, atime, sete Tak teeert ath ACE ob ag oie es Hrd cok CS & aURlop//) | PEt bbb teSSCOM HOG IORHROOHH SSS fons tin: SHWSSHSS txt: Soyisco R ane SNOSW AQ -HHORN -THEDNEONDAAGAHO ARNEHAAROMIISOH WDAARNSRSHGHH Done a 718 TROORN I iirc 1ANSWSRNSHSAS ABH SHHSSHHAR GB Ed IG AE SOS Sota eae = oe em ohoh a m mo Ort & ALL eA Dare ge ota HO Ne i a OT Og Doh halo DE of ai MOSS oer ROS sre tert Oo QS ornrE4+tsy = ADNOO QInydng| EX RASSOM RGIS ItrisadwWiwed Ow 9 NOI + RR riw0191909 SOARKMI MIRA aH AOon 2 “pew 02 a SEMOMSAHOAHAAHSS IO NODARNAAIDINA SSHSCORNAMONSH RAINASCDRNRNAHR aaa Ra Se Bee ee ee ee ce ar Rec at eer ee eeetee tn oe OT atinnat e aetac es RSH AGS <4 (G80 | A RARBRESSRSRRBBSSGRRRRSRRBR S ANHBFRARCASSS Site wert crete eS m PY SrneSe oad 0 : SnHomo > SS of “ueq| 3 a ae Fee es ee MT OT Sh ale oo 5 CPEs aon SS a SS OTIS ae OY SAGA E ’ BEN SRE pe RRR OT RO ISN BS aL RE pela hares rier tara pete paca ag sae ra Sash Mon D 5 tied og 06 68 1G oo ag 2 oe sed A geddgrdisvors MagssstsGa3 EESS A | -nesouboyy DODHHOSOHRRNOIOH NAH OME DONALD Ke CODHOAHISOORAIG WRHNONDSSHSOaND Di= RO Ay $ E WHO GDH Hagatag wer wSnnoooor aot HOES GS HH 910 iG 09 I= WHO GO 6 69 HD GR 10S 4 “pos HF] DIMA SOADNANDNONNONNOKMORAGHSH “OHOOm + -H1ORID HY. - ++ HWS O:- enon 4 B FAT HISO SHA SMM OE HMO SHNAK Sa i) ides : ‘ORS fa rip es wie CenehieSeees airs £9 Hid 68 H noma anmnannonereantoounmonms H SSDHHHDIOAAHrEeSIRN Si ; Teerars Bre re eed aa eres Sepak ee reo ey Hee at rn caer Same bee oe tN Se ng FOO Chee: So sAeag EC eg Moh a let ‘ E UIT) FH wrrneriairga gi sapoga taSscurase gy © etapa acare pe ipaiggs erent May eke 8 Sete a ee ES eae aed a Pe rer ACL CZERBABS i ARS ae AS oa aa x C Ca Grice 4 QQ -Ssewmononoes sent ee oto ary . NG = = ie Diy ase RISBSSISSABIA RSSSEISS :Ah a BAIR IRBs. . 1p BAQRESSSESR BeSRB es MOMAT| Go FArOM AAAS HDD Rado sw i 6 Cel: ee oRedetal ates bie: | Nass ‘eshipUuy| m j I bd Breeds Beers Bm oe a Se os = Pais ane eee a . ol ofa. ES Abe (rye pele be lots ny « 7 o - SESH . . a » = : Oo: 5 o o S) an o nae Oo: oie 3 pdevehesoesicucses asdecig dubd 22 8:9.5°55 e826 aSat Be Sess osssosas ors osln ESSSo5s ase BS S 8 att S253 oO aot = & fai = Set BSE oh ae eee Cabeaam aon Bm e aA 6 ak one ‘ON Sag SRSERRARAREERSSARAT BS5RASSn2R R POASM OO Winwte a) 3 G9 do G3 OD Od 20 00 09 OO =H HH Sia i E webs Se 5 = RARAHARARARRRRRARRRARSEISE FSEALERRESSS HARSESSSESS SSEE GROW. HOW ChOPS “OULD “pany “‘PoVv o2unydmng “DOV 2 ~LOYdsouUT “BULL “pesoubvyy “pos “YSD]OT “Us fo yiandag ‘sashppuy fo "ON COMPOSITION OF THE ASH OF AGRICULTURAL PLANTS AND PRODUCTS. Substance. wawIGe NOOO 1D RNROCHO ooo smoocooe smotooo rAnNArSOrNeaBDoOSCSCS ED TONES ORR SCO IS OR OL 9 PAKS NHAARAMNSSCOnE Oonnr 2 OD rt OD ID 4 1D GOD OD GR CMS DEHNAWCSHSSHINDS TH GRAD So 4 GU OD SO 3 OD SH HD 19 10 9 mr NQrnrn —SCHerDrstre SHReanS igh al HHncsonnse WHOHOHSOION OMIM HARO DASwNnocoervoansoonnn BASH mgKnorrenrser EMS sanstneynan DDDIONADHOPMRNENS THO HE ABR NET eR AS fe He fe be foe bonihenl rr iS CaoMHENDADES OEnSRMSrae Ti9crroels AINQOSONOrow EIS ES Oe NE Ce MANNA NHANANOr PAS eM per ong. See gong tee Ne - ads 5m AW imei) oe Re we POD CS Seay sree Meme a eee Xe Dee Me ern ig ed ae poeta se 33 ES wea Atay eee e. 5 eae Salamanca aes See oe -- [26s n ee Agee ond mo: eS bo, Dag wee om awe oe al iy > ae os © woke as FER. aaigren satce eto ae! Gore Pes Pe aon” Salon ae Lay (m, se Goce oo, 2760 S ‘ sas" stoc egesce es He iis aati = gee Boe ee fan} — Pel C Bepse5o Bisse: ! aased - oases + SuTree Seta, 3 oe PHS - rg ee oS O° 4; SSB RR RES RPELE o * OF SS RRR aD Beit! MO REAPAR Ian E SRESSESSSnaSSs Ray KPik- re ri-rDDOODGDODODO Se ee Oe OO ee Oe oe Oh oe oe BO oe oe oe mAOS HOME OSHS +H. HIER ROS NN ++ somaArwMcHsate 10S Sinton Haat) a o a a ornare alte ta ah Grier amr Meal ratte WHOaGIns 419 21919 4415 5 Hsin 1019 ss 1 9 «ap KaiRN co --S mon Soe OS ees RSABR a 8 ibs DBS no COs sees HSOoSo | o Nod oe ee Heer “ 190 Horse-chestnut, young, aut’n| 1 6 189 Beech....... nt eee : te g : [rei gae: - 2:83: a a: . ESSSERGAs Same RAeee ZASSZRSSE -_ nen 881 APPENDIX. a TABLE II. Cc: OSITION OF FRESH or AIR-DRY AGRISULTURAL F.2opucts, giving on “enydmer| eh 1 iQ OM ROMO MIN + 1100 +0 Ce) Qed eM sss. : + YS) ARRA Rim SSSSSSSSSSS tH ISS tot StS SiS tS tito? a OD OD Os OD et HID SHAM DERNONOS -IIDVOAMDA 10RNRS 0D Glin aeod ia o Ei ea | See eee a een me ee RR Coen Sema, RARER Es eS Jo io aps uechogte | ; S QUuzojyD IDM NAAHAHRR BMOnHOCOCHOHS ‘HOOSOSCO -:CoOon ocooooceocsess (3) aE: : : ef : = PONHEr ORD OIG BAWIG RE DSO Hd RE HO Ho Heo RW NANA ANAO a) “Dares SqnRonnn CRNHH-ODAHWEeSAMIGSSSSOSSSSSS So SeCoooooeS = “poy HOE NaSTinee RDDDSOSIOMMAHARNOANAHAARNMOIIR COM tH+t HDS a Dye ame aS ST AGH oe Span HOSOI Se Sa Nh SP ert Dear Na cere mene irae Mt Sie 2 zs aeinylingt OOM wWHOnAH HSSSHSSSSSSSSSHSHSSSOON ecoonocscocn [ j =F 2a ee “eV 22 ASSO rnetH IONM AIM HUWORNroSMtmaIASOMwoNAaASConN DSOASHAHHOIG s -LOYdsoud sH G81 00 XH19 tH O19 THNANAHAANNAANANNAAAONAT RmnAOnnnnnNon 3 PONQHNNSOH PROSSNNAOGM HAE NGO SH RQgP wna RAIMI ND OSGOH ae aUunT rOGAHHOHOd RNANAAAHAHANAOHNAH HONDO OMH ODED esoosscc]e|es Pa & ja Ries Bee ee, ss MANN 2 SB bes ee qn SoG Neha WORK SY rem leo) sea e eS A ee SACO NRO se te eee 1 Oo | nesouboyy CONSE MAGN BPHSSCSSSSSOSOSSONRHHHSOHHS ,~Sscoocoescsosco om areas | ae ee 3 Ss eel % ae = = (102 : 5 ESSEereanoS SHSSHOHSHAAHA RGARNROG 16 YA RHDRNOSASCH ra ted poy MHASHTSOSOSCRA GnOoSCSSSCoSCOSSS :CnSSoSSSO :O 2 S (HSOSSoonHS a S eS 2e3 a : : 5 : HH HOMDSERSSH & SSanqRnQSsanenoowqusnoox OD SEMOOTARARN mm PY YSDI0T| ee isaowmirsH SHIGSErEOGH Gr HOOGROGH IOI p, WOM HON O = [ae See ee jax] Sh on heh on hon oO mr cos | BRogqontg | HME Aonoonotragnteroowdrmmsd & MaSoenmaay ~ ¥ * coc 19 99 LHONRMARH 1d 69 69 BSWDOMOSADDS = o WY) 4 SSESSSSLS RRRAROSRAR Sts ale A Oo i < esoeecsess Seeoesesssess Sow / SSNOaN =I ™ SESS Sse Dr DRAB oa) Sal = G | “a! SSSESESES | SZEEEOERSE PRES y ESeee5 c = S|) Se Sooo Oboe So fa SEN RIELMMER AGE oO a kee Way Ae OE eer nae p> 5 eeratnatrmere mater sip nits SE RUC aG Mees MRSS ney Weetar te. 'al Taig sce ee Beane See ake SSTag pel ee ea Gahan Cec aia Tuk tea oC eememee aehtRy ay Rati Ia ASSO Gh Gees tiara Sena cage ames Gre GW Be : RP ae Sn SE I re Sw Py i ° a cree Seren MWR: fc RIN) Seca ele VA) es Pais Ta =O ee ee . CAS atin Se Berg eh <8) Spm tab sh ee ee aM he oy a8 5 Sata ae ert Le Se oa) ets ee eee Rat aren me ; pamieha pot TW ge en hy Re eC Ong de ae oe 8 caine te eft Bc eh Osi ce et eT RG lh Le ae See Rrrek one ie ern oreti, pets +. bn S Ds wee ute oe Bet iiss ig Ceci tsi: Oe ear ee Ven CIs ee e me om 38 Be Rt ee dw ene A a 658 PLN en Ole rer ket oP 8g SS so. . x mom ¢ & 2 Pes $B Sato a PI gees oe ee ee : hidewn ie ats o pete preety oe yee ap: ea gegseo ia chm © SO s 7 Sate a ac a e RPS :96:ig2 82: :SESRS es : ISS 38a 2: Bafa Pet here oe a Bo eS On Be (RES to Poe gees is ong Cera ster sheciace ea ae SoS | ieee Be eer ees egal Ol Seo sa 348 BB Ie o E sht= tae 8p Logan AS. Od -o: 3 Pe = =—o OO Es a - GhO osr as So a Sia =| Srsesbban Suis. “bp ¢ Ssoegb ese PERCE LT 4 ae . . 5 > 4 ; SSuasSess Seckek: oe SageLS esas: SES RES Ss ba Sesann a 5 : =} Bameaagso Spmeo6 AF SREaARNS R.nas Ps mR BRESE A SASSeEGRSRSSa A naR8 BAT OMe DHA AR ss S Seoecososoocoe w =) ¥- SORES OSSDNS “dD AL SES “ SSSRSRRz SSSISHBESZSSS 1 GSSSF BRSHRARGRSRRRS ar ar te RO OF Cigat am Cie, ee Ore aa i= Sam he ats Ee ee OM OR ee : Cit =p Sere ae oot: artes ear PaaS ian a\ sew aboe! tat yeh 7at ile ns! latsalt “ef ta wk zalteeins, cook cureiteteetechtc rae |S RCW Yee Cine Tea pom hoe I) 6) AN elas oe By a eA eer ieY we cette) oo (ete tg i, call rele et Wk euatel: 1s Meant SE ca SSO: aes eae earn ere ser eect ee ees a, ial ta oes ap Das Seema gaye bates (8h Cale Pl ete Fave) fae Musi, copete «athena mmo UMetiea gv ele “me : pun Sark mere core Lae Mar a rere Wee er 2 : : ‘ae ; : See Fite erreris > Sa) = Re pera ra Pe ger ante rere 3 ce paar cpa CP ACHE = eam 4 Se steer ere Reh se Sees Tele hn Ae Ocha Eels § eH Ear 5 mea erai el eo ates ree A 1 ie RE ae mae Ste LC eS ge eee oo ee “mn §8 -sasq . :Ss es: 73 Siac cratelyy ORAL leq" je) hes" Osc ieee 3 . Aon = 10 ° S58 . ei Se Deroy Roy eee CB itis . i 2es * Hw APPENDIX. 385 ins TABLE IIL PROXIMATE COMPOSITION OF AGRICULTURAL PLANTS AND PRODUCTS, giving the average quantities of Water, Organic Matter, Ash, Album- inoids, Carbohydrates, etc., Crude Fiber, Fat, etc., by Professors Wourr and Knop.* acs - Substance. § |s8] . |§siSsigt S |S5| 'S |SSISE ts S = ISS| 3 ISSiSSISSI S HAY. Meadow hay, medium quality,..... oSerowcewoona 14.3)79.5| 6.2) 8.2/41.3'30.0! 2.0 NE REE ahas -ncsecisinesitves sess sc a eeee {14 3/79.2) 6.5, 9.5:45.7 24.0) 2.4 Ruediclover, fnil blossom... ..........0-s00020 16.7/77.1) 6.2 13.4/29.9 35.8] 3.2 : or MGs asl cays 10 S> 2D 00 Noto SoONsDANQtRNvo te SNMRonrno SELSR 72) 235 oe eo os Ph oe | Wri Ge 6. sew ee ie wee we) 8) ate igh Ne : 2 e@ +O . Sea at Ser eae eet ate wen O Mateus he Sa er Mo ee ea ee ¢ Lee ws ates ° re ork eee eee ee SRA Ker rg HEE, . “ee gee os he Rigietai $) anne i aaeoea” * + ale EPRSo me iiii: n + “Oot eee bh hh HD Sol otis) 8 Oe = a ree Br i) Seog - es) Aree N 888 8: eesadarnd Beebe S SOLVES ESn OFPamanas ~~ DOMHrDOHDDDDODEDDSEeErDDDSD | ee UL SOM, Wart Sed le a eee PS ee 100. Be rh Cie whe "ks aw i ap ae eee 5 eee oS ee eens Sele german Sele PREM eo ee ORR Tce, Reuse aaatee ‘eo (02a) Sd. at es ew 2 8 « 0 eo ew" N we te te ee ee . RR ES Wis wage. tee A 7s a) ee ey Gee me eee ie ee IS =olG) Kae, Oe L SOS ee te ve 1 ie | ie ° SSS Re age an ee Mec a eee aus BW fe. Bee Ue te wee Ts . 3 eee. SS a a Oe ee See Sia S és. SOs She estat SIS See on eae Fetaraee eee, os Peace et Spat erated SER ce aie ees SES a es ae Bucitays, SUNS SER ee ole a Sie Sen, Ane Rok ens Sein Ry sie. is cose oe B asigs Ape nel mee re. Salma 76 ee le (8 eC ec ret tt als ie aie 58) a a8 ‘2 ')3. eae Peco = ghar rb SES ae Gee = Stee ae Spa Soa F Sant: geome Brakes - so tee 7 . SO. 6S hi a eee ee cee . g roy Seri =) | Sate Cy Bee ern Ss Se = ce te to) = «© o@ fo) a alge) 5S es) be) uy Saiataat hie is ea OR REECE rene Mea Natt neh ohh OES cig Bie aby a ee o--* S, ipa Sie Ds Rar ue'a 8 gy, oe AS ot = o: siKne» Slice Ser ® < (8) 8) pe Oe ad Bebe Bo ey 6 tpt Se heat es oa 2 8 Cf88Se Tes22 8:4 8y5 iid Ai: 5S i Cima tow tree =S88_ :22 :sg: SPSS: 9 loge 2 iat SSss :2ae—5 2 ASE” S: poe Be 2 :°pES yp Elo se Ph Ss sabs?S s bh Qesessb (Ba s950 o = 9 PrmosonsS x Saag Ss -nmosave P ~o . SOR°Ss FE i2VESSao oats , St oS Bf Speeos S's ssSrs fee 8- 2, O° SOs Staak Oscars IN. PHS ss voOSoa » oe o 5 aSabSaeBons ESSso Ghasa g° 3 Ee 3 Bao soSan8 SSs82'3 escka Oo nN vw AMMA n>ACem=e S4FROC OAM 387 \. APPENDIX, PROXIMATE COMPOSITION OF AGRICULTURAL PLANTS AND PRODUCTS. “op “VOT “ogy apnd) ‘oop ‘sayDup -fyogin/) OD ID CO Ge rt rH PH ROR rt Pt CU rs oooovunrcooococe IND INAINS OI HWSSSCMYrMOHSCOSOHMINOCOOCCS Tt GR 4 GIG OD GVGRGR NQnrowmwrn_-: Onnne OrORNa QO Ht or B5SBaa MAMCNAIDHreNCOCOS MANN On nnn STOMAtMNOORAMO TINE ES IDGODINODOR NQrn mr con! BS P10 1919 1D OO 1N HOMNOAIGOIN DON GHA oO SHSESHHOKSHSIOSGHSHHNSCOrSORST -_ bon! rm hon re rm nmr IW GSADRNMOS SHROHONMDNOSHIHNOOWREOO ESN SSESSSSSSISISRSRILBBBSS com “spiou “UN “USE “LAND a2UDbAC “LAD AL Substance. 2) ee wy SSRQMHASOSORHDAOO INO DS O19 5 10S 019 010 WH 18D IN DOO M10 HO 1010 EPOHSHSAANSHAKAIGHHAGRNRGASASKS nonnn Bam RRARRS” RaRAsts Or 16 Gest Ox mr oon to) MMR Organ eoos SOM FHRARIOROD WOW -NNMOWOSWOSIW SHH HOE HOErMoHeR ae | Shafi hen hed SONA M NM O10 WO 4 Peele rec hichecaches ex SOP BOAISEsBRah SMORNMNS 190 MO © 10 09 6910 OM a pcs Me ches pellet ello) PTIANENSODDNDi-~ IW DMADCS MOS HOW INING DOOCHMOANORN HRD OOM END HHAIH Cron COnnWOCCODH DAIS OD BI 4 GU GRD GRAD RGR GR OD OD OD St st HIN ON HH ee OA SOD>COCMNMOnANMOMrero Pe ee ee, ee ee Oe ee Se eee ee Seema aa rar eee a [oon ren mr oD OD OD OD OD 6D GI GIG ise) oD QR Sonor ron SUS A See a Se is FBSSBLBHSSABSSBBBCAGSRBOLS BOTS STRBESSEDSE GE SSesonosow omg Se eee ee ae a ees oe eee SEEDS SSCSHLNNAW SWS Woes oo bond (ni we co i) Sarwoowor OD GAD SOK ORDO OER A BNI NNNN NNN NMR AONOAMS KLSSSSSSLOK Masons eee ky RO | aa cee OR Sr ee gare ia ere LC Se SECT Sh ak ASR ACS Gast gone: apnea cee SEA are a area reer nia lt = ba Shige ga Srtaree ee aces See cites etuivateihe cs kate Ete sapets its. ceNee i ts pe cp iecu pacer pete a (tc ‘ Rue tec at ainiae (ee sarees or ee er ee Sed Statins tea ee SLUM teas Shoe ay mee Aalares (eat tes protec eS Hae eee ae Bey sere ive: sags) 8 g es eae Puen be cos gigi” MRpa se yo ty so ete: pubemecanne Rei eae ke gone Se oe Tay Civeplserpe aoa SEADOIEE SEL CaviSE ‘Sais es cic pcuen sien sateipincarie hie Se Sh cere ape ahs aes “Se a emo mies eirte jai SS TS: BUS fey Veh age NoMa sibgubsr ks anatwe aagiolrseeeiemne tens Aw eas Sea) ape. (Oe ae ee ee a ye) 8) Ya, cS 8 wel we cee mia’ ee ea CR a eee Cee OM URC cara cee ee ear q seme iseieines TEC eRe! Of = So CRC IIS Niche cee a DOs aca Meta ae cSt eek Tied | Ser ele at ae oe 5 efalee ia? GaRR PRA oo ete es WQS ietia tel “ay lente cee ena nes Re Teer eibiar Fay! ere aigd man ime. ce. a Keg. Ceacreutans . oo. :og . etch Seay ss oat tae Shae Ado cin seacatee Soe nO Sree cas pal ntl el I stay teat S Rare re meer a eae : etcetera ih tii ee He et Sere JG) meee: Besse eR E gh cs SNe « ~ ail deine Sala gaa. aeuahes meee ee ey ae eD Ses syesete ee hs SEEN Ny ee ia alee etas AOS, aie catia ceeare Rees Sa Pp 2G Saouda S ee a ene here rere We (2a, ,sSALs os Fa -eras. o8 Amo be Suen aseaqio BESELESEGR ag SASS See eN HOGS E SE Bo yQsg am epee Ng Fea > o'52ag SELSTHLEEEEZ CADAVERS IR ofaeagas eo gakas :oPaceneopeohas ODS S Sas ece5sasn ame SSeS sess sosggagto BgSSxR2050 s° > OF, ES eel hs. Gsatmanocenae REPAERERSSeareesas SSeexi&n 2 Cees oenaeeeas 388 HOW CROPS GRUW. PROXIMATE COMPOSITION OF AGRICULTURAL PLANTS AND PRODUCTs ke. |S = ss § Substance. § |§8| . |Sgis8i8el = Sel} s ISIS IS S S| 's [R's Sis 8 E ISS| = RSISS$iS8] 5 REFUSE PODRVICAR GS eaclidcseic Hebiane ccea ass ulsimcisis ss ..e--/10.0/81.6] 8.4/32.5/87.7/11.4; 8. Hemp cake..........- saptereaee ret 1IIII}10°5|85"5| 4.0/27-0186.5/22.0] 6 & Beechnut CAR Gsce serene as een aw aiaele eee wees |10.0/84.8) 5,2/24.0/81.3/20.5) 7.5 *“ without shells... .... Sevciecialee eh 12.5/79.8| 7.'7/87.3/36.9] 5.5) 7.5 GCL MHOISNEGHL cece vac cha wasn sleeeble ecole nent 16.7'72.5)10.8} 8.0)64.5)....].... Pee MR co roo 2. okcaue eee cokes §2.6|17.1| 0.3] 0.8115.0| 4.3] 0.3 COFFEE. TEA SEAAT CS ROBYN fe dyn ars cinta en la’my cole tioieinia'a)p oiaiclaaials'elein aia 12.0/93.0] 7.0}10.0/49.0/34.0/12.0 Chocolate bean .0/85.0} 4.0/20.0/52.0)13.0/44.0 Black China tea .0/79.0! 6.0] 5.0/32.0/40.0; 2.0 Geren. “Fs -0|79.0} 6.0 5.0127.0/45.0| 2.0 TABLE IV. DETAILED ANALYSES OF BREAD GRAINS. s |./8] (8s. Rel 'Sle8| jess § Analyst. &§| § (ESS ESS 5] 8 3813S ISSIR 18 S15 WHEAT. from Elsaas........ oo eeee (14.6/59.7| 7.2/1.2) 1.7 (1.6114. 0! Boussingault, BE SBEODY nc o's sis.0%.s0='s 11.8)64.4) 1.4/2.6) 2.5 |1.6,15. 6, Wunder. BS) CAMNGTICA. cece e. awn o 10.9/63.4) 3.81.2) 8.3 |1.6 10.8 Polson, BS. OAM COTS a5 sais cre sates 10.7,61.0} 9.21.0) 1.8 |1.7/14.6)Peligot. “© Odessa .. 14.3)/59.6) 6.3/1.5) 1.'7 [1.4/15.2 WD as or eae --- {18.6)57.9) 7.9/1.9) 2.3 |1.6)14.8 Me x Poland . +» |21.5153.4 6.8/1.5 Ay ¢ 1.9)13.2 - =e Hungary.. E asalans ~- 18.4/62.2) 5.4/1.1) 1.7 |1.7/14.5 oe = nstale-etp Sala ath erate \20:6 150.4 6.0\1.1] 1.8 |1.6/14.8 “e RYE. PPT TICK cinciec ce sacs 13.6/50.5| 8.9/0.9] 10.1 |1.8]15.0/Fresenius, aC SEWARCO:. cei eee se oice'e 11.6/56.5/10.2/1.9) 3.5 |2.2/14.1/Payen. SS IBRONY o's.6o 20s sie oicios 9.1/64.9] 0.4/2.3} 3.5 |1.4/18.3/A. Miler. a is hay eee} 9.6|56.7| 6.4/2.1] 8.5 |8.3]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 Salzmiinde, Prussia] 9.3\60.4| 1.2/2.0} 9.7 |2.4\15.0|/Grouven, OATS 8.8)55.4| 2.5/6.4) 9.6 |2.7/14.6|A. Miller, 15.7/32.2)... \.- .... |4.1/12.9/Krocker. JAD Blise cnilie-ne 16.1] 10.0 |2.'7|12.6| Anderson, BUCKWHEAT. Husked, from Vienna...... 2.6|78.9| 8.8]0.9| 1.0 |...|12.7|Bibra. Side 8.6/%6.%| 4.3/1.8] 1.3 ]...]18.7) * e Wekibacbusestaee 1b: ie | aR ee 3.9] 3.5 |2.5/13.0|/Bouss ult. THURMIO 60 darcvievaws weeps 8.5/87.8]....]... 2.0)14.2/Horstord & Krocker ba Sarak e's ofe'o6 wialels 9. 1/45. 0| 7.110.4 22. 0 |2.4/14.0 Zenneck, MAIZE. From Saxony............. 8.8|58.0| 5.3/9.2) 4.9 |8.2/10.5|Hellriegel. 66 AINGTIGR.... wiivceicnes 8.8/54.4| 2.7/4.6) 15.& 1.7/12.0/ Polson, MAAC E eo ve necweve obs 9.1/49.5) 2 9)4.5) 20.4 |1.8/11.8 » Switzerland .. stpainerabeicifiniae's 51.2! 6.7/3.8! 12.5 |... |10.6|Bibra, So APPENDIX. 38) DETAILED ANALYSES OF BREAD GRAINS. 7 ae Balt lesiclssaic|§| 4am Rs] 5 [FSS ESS Ss] 8 =sie (Sain la I3l& ts RICE. From Piemont... “Sueor aso] Wes] eee feped 0.5| 0.9 |0.5/14.6|Boussingault. PEPRITEH Ee cress. cio, vaic'e %.2/79.9) 1.6/0.1) 0.5 |0.9} 9.8}/Polson. REP IeMON tse es 6.s'cces 7.8)....|. ..|0.2) 3.4 10.3)/13.7/Peél.got. “© East Indies........ 5.9|73.9] 2.3/0.9] 2.0 |...]14.0|Bibra. MILLET. Husked. Hagenau.. EN DOLG|rscelliee:e = \8.0| 2.4 2 .2/14.0' Boussingault. BS Nuremberg .. Mreiccs ..{10. 3,57.0/11.0\8.0| 2.0 |12.2' Bibra. TABLE V. DETAILED ANALYSES OF POTATOES, by Grouven. (Agricultur- Chemie, 2te Auf., pp. 495 & 355.) White Potatoes, newly dug, Various Scrts. Aver- unmanured. | manured. | age of 19 Analyses. \Wei 14.95 78.01 76.00 ain etteran ctevalsiatwlciaimets e(ee'f ea Hie PIMC ER ietelel nll ciselniaicielc wa\eeee cece . * Gliadin & Mucidin ()..: } 0.20 72-14) 0:95 ¢—8-19 2.80 ePID ee ek cic'c nines. oe ses 1.31 2.02 RWG ATA DECUN. «2 00 ccccpees 0.76 1.56 1.81 ag AGIOS. Saisiccicee are 2.00 1.50 En « eree ac rciciios seis 0.07 0.05 0.30 2 are 17.33 13.40 15.24 ROCINMOROE rele decisis cc ciacese ces 1.90 1.24 1.01 ASHE earner bcesicessscesieees| 0.88 1.05 0.95 100. 100 TABLE VI DETAILED ANALYSES OF SUGAR BEETS : ee ee. § |5g| § [Rel8g| g | 4x § Ss) £ |Sse] 3 Hohenheim............222e00+++e00+{91.5/0.87/11.90/3.47/1.33/0.89) Wolff. oeckern .... Biais(Wie sisisiais.s abineian sists 84.1/0.82] 9.10/3.90/1.05/0.99| Ritthausen, 2 Ibs Watdieietsisie Recoricacece 81.7/0.84/11.21/3.86)1.36/0.94 a Ue Brauer melalelas tere.e\o'e(e/e/s vie'e'ciaa's 79.5,0.90/12.07/5.09/1.52/0.88 Uo Bickendorf, gt Bescc ek cicic's dc cet cies 80.0/0.70/12.90/5.00|1.20/0.70)Grouven. He Blanstidt,2 Ibe..................--|80.0/0.68/18.37) 5.21 |0.74|Stéckhardt. Lockwitz, 1 1% Ibs. uteiatetetataisiele ste seiolaiwe 79.910.65/13.82) 5.53 |0.60 ls Tharand d, 1% * ae manured ema ccen 82.'7/0.93/12.34) 3.24 |0.79 as eee esc ceniSl sitio lOsdb) (bev |1.12 oF _ 3% ‘ st piavelaielatelciete 82.1/1.14) 9.25) 6.36 {1.15 = LS As. <5 Sefeticielsiaiets 82.5/1.05| 8.45) 7.07% |0.93 Silesia, unmanured.. _............ 84.4/1.14) 9.80} 3.96 |0.69/Bretschneider, “ "manured with nitrate of soda|82.7|1.42/11.57| 3.63 0.68 “ % man’d with phosphate of lime|84.1|1.20 9.82) 4.04 (0.7% as ee \ee098' 15 37113081 HOW CROPS GROW. 890 “919 "BUTYG “Sspe0g Ul pepufoul Apeoipy ¢ “plow ol vu pozerpAY sv possoidxg 4 “aso10NI pus osOIByOIVS » 000° 00T||08T'88||099°F ,(180" ‘0,070: 0, O89°h ||096°L ,088°0) LET |S99°O,OTT'T.eOL'e |ggsT*” "Tt t tt ett tT Bhs es “7 Wepres “OITA 000° 00T||L99° 98 809° [(966'0),209°0 | 90L'F |/SE8°S FISh'O| OFLT |FFS'0. 98G"T/80L' |SgBL"*** "°° Cee ee Opis DORE © 000° OOT| (098 al: FET'0)|08T'0 | O9h°8 ||009°% FOLG'O| LOTT |9F9°0,086" T\L69"S |FSBT"*"**"* SORE Re = eae De Be "SHIMaATISVyYy 000° 00T| |FLF'LS||098"s F(FST"0)|006°0 | 096°E |/999°6 FOSh"O| GIT'O [ce OSETTSL9°L |gagt ss*tstt ttt es iM A(OOT” 0) 8080 \¢rr'0 lose" 000° 001 183° #8] |L96'E (L480 Str'T 669% Ze S"0) ees |9¢8" 0689" FIGES'SUGGQT tee Cece csceweee 00 OOT !og0° $8} |246°% §(690°0)|S19°0 | BFFs ||ET0°6 |SSh'0| SISO [err O/SAT T\OSO'9 [FaBE "TTT TTT TTT Apyqad ‘pas ‘quag * 000° 00T| |egq° ¢g||296°¢ F(9PT'O)|F65°0 |GI9"O)TSh"S||SPLTTPATS"0) 696°0 |THh'0|888°T 90'S |PasE "Tt stores oe ApH ‘por ‘eSuvq - | *SaTNAATAsSOOH selfs] 2] i8] £ | Se[seigsdel FF] € Sc 1es| = Rs By gS RS gas a lhe) S se 5° a “Bis, less] F | 2] Pr : So Sek a= Sh 2 E/Pelsssa| £ at a Sa nak & ia ad Bi LORD || MONI eQnjosu P suas ‘srs! “SLONDAT eqNI0K7 Cete 4 ‘Tot “ud “2 "YO “wuUy) ‘“SHINASAUY 0} Supiooo8 ‘gLINNA AO NOILISOINOO— IIA WIAVL 391 APPENDIX. 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FRUITS ARKANGED IN THE ORDER OF THEIR CONTENT OF SUGAR, (average,) FRESENIUS. per cent. per cent. LE C10 Ue apg 1.6 MOTTA esissnciwiamiane a6 6.1 PANES sie 51: pia.cis vs cherie wae 1.8 PUTING Se ne taseis ak cote cies cckoters 6.3 EMEEPIE Vl inicisrecicicoasnioe o's. 2.1 Goosebermitsscasaccseeseeee 7.2 IREGMGCIANIOES, «cs ciereccee sees 3.1 Red PAESe awe nein “cee V5 EMILE eGo nciencickicbee «ce 3.6 y-\ a] | eRe See TERRE ID Sch atiog 8.4 Raspberries ....... eAreeiehsisais «fs 4.0 SOUP.CHEMTICS. 2 <7 cuicaciee = - 8.8 IBIGURDETTICR. (0... sew oes 4.4 IMMIDERes | oso cnc canee ee) BEIAWDELTICS, 1.05. ccmeeeee os Bit Sweet cherries...0....0. .» 10:3 Whortleberries..............- 5.8 Grapesice, asf neon ceeews 14.9 TABLE IX. ¥RUITS ARRANGED IN THE ORDER OF THEIR CONTENT OF FREE ACID EXPRESSED AS HYDRATE OF MALIC ACID, (average,) FresENIUs. Lilid! (Se Blackherries. Mirabelles...... ral} Sour cherries i PUN Sere elc <.ciele = Wiortleberries.,.........0. » 1.3 Sima PEYTICS. «5 chm viseinjaleisiarele < 1.3 GOOSEDEITICS.. «2 canescens 1.5 s : RaASpdervies: cceccccwees Nee aco PPEMBCCIAD GOS... <)610 100:0;0-s100 0/0/01 0.9 INITIO CLINGS Soe cere cnierciee cia meieie 1.9 EMEP UUS sicic cits: wrcle'e cieia dais. o'eie 1.1 PO RTEAMIB, SSicines cmt resteerteniee's <- 2.0 TABLE X. FRUITS ARRANGED ACCORDING TO THE PROPORTIONS BETWEEN ACID, SUGAR, PECTIN AND GUM, ETC., (averages,) FRESENIUS. Acid. Sugar. Pectin, um, ete. RE LLTII MIR iS asii5)s c.si0in's ic, craisiece aie one's 1 1.6 8.1 Apricots. 1 aI | 6.4 Peaches... H 1 2.3 11.9 Raspberries. H 1 2.7 1.0 Currants....... ater 1 3.0 0.1 PREMLCU IMM OOS cio) iis aivp.c.0i6 ace eon.c oe cleeee) 1 3.4 11.8 RANG MIAE Poo, Fok widipic'cje eel e.aisewesis 1 3.7 12 PUI CEIICH ec tadicc cc oe slioeecdsac 1 4.3 v4 Strawberries ..... Retr teisiciel=ieiaie craisriele 1 4.4 0.1 MEPIGREDEXIICR cdcicie cine cielvicscvcneccee see 1 4.9 9.8 UB PEEEER ec inicle cies c.civiccis FOR THE} Farm, Garden and Household. Established in 1842. The Best and Cheapest Agricultural Journal in the World. The American Agriculturist (so-called because started in 1842, as a Rural Periodical) has been greatly enlarged and widened in scope, without change of name, until it now meets the wants of ALL classes, in City, Village and Coun- try ; it is literally EVERYBODY’s PAPER. It helps the rAnmeR, the GARDENER, the FRUIT GROWER, the MECHANIC, the PROFESSIONAL and BUSINESS man ; it greatly aids every HOUSSKUEPER ; it pleases and instructs the your and the LITTLE ONES. “ It is eaited with great care, labor, and expense. to have every line reliable. while its pages abound in a great variety of useful, practical, reliable information and sugyestions. 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