AGRICULTURAL CATECHISM A TEXTBOOK BY A TEACHER fflwmR'-i tauAMf wertA EX LIBRIS CLASS OF 1886; PH.D. THE JOHNS HOPKINS UNIVERSITY C375.63 G73a FOR USE ONLY IN THE NORTH CAROLINA COLLECTION Form No. A-368 Digitized by the Internet Archive in 2019 with funding from University of North Carolina at Chapel Hill https://archive.org/details/agriculturalcate00grad_0 iree u /4-u t* C C\ /ec/i AN * OR, THE CHEMISTRY OF FARMING MADE EASY. A TEXT BOOK FOR THE COMMON SCHOOLS IN NORTH CAROLINA. BY A TEACHER. WILMINGTON, N. C.: ENOELHARD k PRICE, STEAM POWER PRESS PRINTERS, JOURNAL BUILDINGS. 1867. F ) / Entered according to Act of Congress, in the year 1867, by B. F. Grady, Jr., In the Clerk’s Office of the District Court of the United States f the District of Cape Fear, in the District of North Carolina. ^ _ j 7YU^ &lAJC JX~L- y^ Z£~, /VJ i -. X-^l tUt^t u / f*(» 2 A^a /U/7ytsy s*+ 4 , +^CC- ULp U-s^^ *> /*■* + -* -v^J% - 4. fitrpAUjut, far * A^w^T qLS ^ 1 — /t*siA**, A- <<9>C«^4X4 • ^.. ^ /Zpsi ^a*V<- ^-5 ®- 6^o.~ <$ ftf • jJ-o+a., Jh £.., lJ-i^j tU+jLj / «?•■ C /3. * ^. JT L^. 4**-+ f> 0 % This little volume lias been prepared to meet a want which the thor has long felt in his own school. Very few of the young men of the country can hope, if it were sirable, to succeed in any of the so-called learned professions.— le cultivation of the soil is the business to Which a very large ijority of them must direct their energies. Notwithstanding this fact, very few of our schools seem to regard e science of farming as worthy of any attention ; and probably e chief cause of this is, that we have never had a suitable text- >ok. The works of Liebig, Johnston, Stockliardt, and others, are not ited to the capacity of those who are not acquainted with Chem- ;ry ; and even to those who can comprehend them, their views em often to conflict with the teachings of nature. This volume is offered to the teachers of North Carolina in the >pe that they will find it of some value in arousing a spirit of quiry among their pupils, in regard to the long neglected subject which it treats. If it contains errors, the author will be no less eased than they will, in having them exposed. His experience in actical farming is very limited, as the reader cannot fail to dis- ver, and he has never conversed with a practical farmer who, at ■st, agreed with him ; but after a full discussion of liis views, eir correctness has seldom been denied, and it is this fact which ls encouraged him to present them to the public. B. F. GRADY, Ji\ Neuse River Academy, Wayne County, N. C., June, 1867, t t * 4 * atomism. LESSON FIRST. Three Kingdoms of Nature. Question. The earth and its inhabitants are divided into three isses or kingdoms. Can you tell me what they are ? Answer. Those objects which do not possess life, as e land, the water and the atmosphere, are classed as e Mineral Kingdom ; those which possess life, without e power of locomotion-—the trees and the plants—are issed as the Vegetable Kingdom ; and those which are dowed with both life and locomotion, are called the nimal Kingdom. Q. What supports the growth of the Yegetable Kingdom ? A. Elements or food furnished by the Mineral King- »m. Q. What supports the growth of the Animal Kingdom ? A. The Animal Kingdom lives on both the others* le Mineral Kingdom supplies it with water and air, d the Vegetable Kingdom supplies it with the elements its flesh, bones, hair, &c. Q. Do not plants derive nourishment from the Animal Kingdom? A. Yes ; when an animal dies, its body undergoes a ange, and is re-converted into its mineral constituents, .d then serves as food for plants. The case is the same ien a plant dies. Q. All plants and animals were once earth, air, and water, then? A. Yes ; and will become so again. Q. If that be so, some of the substances which compose my dy may have been derived from the moss of Lapland, or the ge serpents of South America. Is that the belief of philoso- ers ? f 8 Structure and Composition of the Earth's Crust. A. Yes ; nothing is lost or destined. When wooc or flesh rots, it undergoes nearly the same changes as whei consumed by Are. It is ’converted principally into vapor, and gases, which are carried by the winds to distant parti of the earth. Thus your body, when decayed, may fur nish food for the tea plants of China, or the vineyards o France. LESSON SECOND. Structure and Composition of the Earth's Crust , Q. In order to arrive at a proper understanding of the mode i which, and the sources from which, vegetables obtain their food we must have a correct knowledge of the constitution and structur of the earth’s surface, and of the constitution of the atmosphere We will begin with the earth. Caii you tell me its condition as fa down as the roots of trees reach ? A. Mines, railroad cuts, wells and hillsides show tha the earth's crust is composed of layers, or strata, of vari ous substances and various thicknesses. The top stratun is generally sand or clay; the next one is clay, sand pebbles, sandstone, ironstone, limestone, or some othe rock. In some places we see several thin layers; ii others not more than one or two thick ones are exposed. Q. Do these strata occupy a horizontal position. A. No; they are neither horizontal nor continuous Their continuity is very much broken by water courses the streams having cut their channels, in some places through several strata. In some instances they are hor izontal throughout a considerable district. Q. What do we find in these strata, besides the substances yoi mentioned ? A. Salts of potash, soda, lime, magnesia, &c., water and compounds containing sulphur, phosphorus and othe substances which plants and animals require, Q. What is potash ? Structure and Composition of the Earth's Crust . 9 A. It is the substance which we extract from the ashes of certain trees for the manufacture of soft soap. When purified, it is sold in the shops as “ concentrated lye,” pearl ash, saleratus, &c. Q. What is soda ? A. A substance resembling potash. It is extracted Prom sea-salt, or the ashes of sea weeds, and is used in the manufacture of hard soap, and as a substitute for ^east in making light bread. Q. Wliat is magnesia ? A. It is a white powder, also resembling potash, and is extracted from certain rocks. It is used as a medicine. Q. Are these substances necessary elements in the structure of plants ? A. Yes ; there is no vegetable which does not yield an appreciable quantity of ashes when consumed. These ashes are potash, soda, lime or magnesia, and generally more or less of each.* Q. There is some mystery about this. There are fields which rave produced crops for more than a hundred years without ever laving had any manure, ashes or lime put on them, and the crops ire as good to-day as they were fifty years ago ; notwithstanding his, no one of these salts appears in the soil, in any sensible quail- ity. Moreover, if I should remove all the dirt from around the roots of a black-jack and lixiviate it, I should scarcely be able to letect any potash in it. How do you explain this ? A. The several strata composing the earth’s crust, as ;aid before, contain all the salts needed by plants, and ve can readily understand, therefore, that the supply is nexhaustible, and we shall only have to explain how they ire brought within reach of the roots. Q. You mean, then, that the salts are brought to the roots, in¬ stead of the roots going after the salts ? A. Yes; the evaporation of moisture from the earth’s surface causes a continual flow of water upwards from :he depths of the earth, which brings up the potash, soda, &c\, in solution. You know that they are soluble n water. * Ashes contain other substances which will be mentioned in due time. 10 How Plants are Supplied with Moisture , dec. Q. Lime is not soluble in water, is it ? A. Yes ; ovsters, clams, &c., in the oceans, and mus- cles, in the rivers and creeks, construct their shells outot the lime which they find in the water. Q. Whence do rivers and creeks obtain their lime ? A. In some countries there are immense beds of mar¬ ble, chalk and limestone, and where these are wanting, we generally find beds of marl. All these are salts of lime, and are gradually dissolved by the rains and washed into the streams. LESSON THIRD. How Plants are supplied ivith Moisture , Potash , &c. Q. Can you now' tell me what becomes of the water that falls on the earth ? A. One portion, if there be much of it, runs into the creeks directly ; the rest soaks into the ground and de¬ scends to an impervious stratum ; here it stops, occupying the level of the wells in the neighborhood. Q. What is an impervious stratum ? A. A layer of clay, or some rock through which water does not penetrate, or very sparingly, if at all. Q. What becomes of it then ? A. If that impervious stratum slopes in any direction, the water follows the slope, until it comes to the boun¬ dary or'edge of the stratum. If it terminates on a hill¬ side, the escape of water is often so abundant that the earth there is veiy damp, and sometimes the water issues in streams constituting springs. Q. That reminds me of a strange phenomenon I have often witnessed : I recollect a small branch which crosses a road, and X have often observed that although running briskly in the morning, it would be dry in the evening. Can yon explain it ? How Plants are Supplied with Moisture , dec. 11 A. When the atmosphere is dry and the sun is slu¬ ng., the water which issues from the hillsides to supply iat stream is evaporated ; hut if the atmosphere is damp is unable to absorb the water as it comes out, and con- quently it accumulates in a sufficient abundance to rm a current. Night would also favor this. Q. Why is this occurrence a sign of rain ? A. Because,, when we see water running in such places e know that the atmosphere must be very damp, and nsequently a rain is reasonably expected. Q. Well, a sharp-eyed farmer ought to be able to be his own >ather table. But you mentioned an upward current of water ? A. Yes; besides the lateral escape just described, there always an upward flow to supply the loss created by rface evaporation. As soon after a rain as the sun id atmosphere have dried the surface of the earth, ca¬ llary attraction brings up more water to moisten it.—- lis is, in turn, evaporated, and leaves room for more >m below. This current, you recollect, fetches up the bash, &c., to the roots of plants. As our crops do not extract from the water all the salts it s in solution, there must be an accumulation of them in the soil, er two or three weeks dry weather. What do you think is the isequence ? A. The pores of the soil become choked, and prevent e further escape of moisture. The ascent of these salts of course, stopped, and the crop languishes. How can this be remedied ? A. By stirring the land or breaking its crust. J. Why does a heavy rain injure a crop ? A. Chiefly by patting the soil down, and thus lessen- r its porosity; but it is not unlikely that an excess of iter dissolves and carries down, out of the reach of the 3 ts, all the soluble substances in its passage. In this se the injury must be considerable. 12 liotation of Crops , (be. LESSON FOURTH. ^Rotation of Crops , cfic. Q. Why does it damage land to plant one sort of vegetable or it every year ? A. Every species of plants requires a certain propor¬ tion of each of the inorgonic elements (salts) in the soi" to insure its vigor. As every plant extracts from the earth more of one salt than of the others, of course e repetition of the same for a number of years destroys the due proportion. Q. How would you remedy this ? A. I would restore the deficient salt to the soil, 01 plant some crop which would remove the other salts ir larger proportion k Q. You do not understand, then, that land is exhausted wher it fails to produce the same crop repeatedly for a number of years* A. By no means. Q. Do you think there is any difference in lands, in this respect ! A. Yes; if the impervious stratum or water bed b( several feet below the surface^ there is so much room foi diffusion, that years may elapse before any salt can be come injuriously deficient. There are many fields ir Eastern Carolina which have produced crops of corn and peas together for scores of years, and supply potash, lime &c., now as abundantly as ever. Q. May not these two plants counterbalance the action of eacl: other, so as not to disturb the proper proportion of the salts ? A. Perhaps they do. Analysis shows that corn re¬ moves from the earth much more of potash and soda than of lime and magnesia; while peas exactly reverse the case, removing much more of lime and magnesia. Q. Planting these together, then, is about the same as a rotation of crops ? A. Yes; and here- we have a striking proof of the goodness of God. Corn and peas are both valuable arti¬ cles of food for man and beast, and planted together they Botation of Crops, dfcc. 13 carcely make any impression on the mineral constituents if soils. Q. What is the case if the water-bed be near the surface ? A. Of course, one year’s growth, of peas, for example, aay remove enough of lime and magnesia to destroy the Lue proportion. Q. How could that be remedied ? A. In no other manner than by restoring to the soil he salt or salts which it needs. Q. Does the earth furnish anything else to our crops besides hat you have mentioned ? A. Yes ; iron rust and sand are found in the ashes of lmost all plants, and the rust of manganese in those of few. Sand is dissolved in the soil by potash or soda, nd carried up and deposited in the bark and leaves, for he purpose of strengthening them. The sharp edges of rass leaves depend for their firmness on the sand they ontain.* Chlorine, sulphur and phosphorus are, also, found in he ashes of all cultivated plants. Q. What is chlorine? * . A. It is a greenish gas found in common salt, and in ome other compounds. Common salt is composed of his gas and a metal called sodium. Calomel is the same ;as and.quicksilver combined. Q. In what condition does sulphur exist in the earth ? A. Generally combined with oxygen gas and lime, a gypsum, or with the same gas and iron, in copperas, ’hosphorus is generally found in a similar condition. It nites with oxygen and. lime or magnesia, in phosphate f lime or phosphate of magnesia. 14 Constitution of the Atmosphere , Ac. • i ’ LESSON FIFTH. Constitution of the Atmosphere , and of Organic Matter. # Q. Well, you have pointed out the sources from which planl obtain their mineral or earthy elements. We will now examii: the constitution of the atmosphere. Can you tell what it is con posed of ? . A. Oxygen and nitrogen gases are its chief constil uents. Q. Tell me what oxygen gas is ? A. It is the vivifying element of every breath w draw ; without it, all animals would perish. It is th substance which unites with the fuel in our fireplaces an stoves, and carries it off-in a gaseous condition ; withou it, all our fires would go out. It is the substance, more over, which unites with iron and other metals, producin rusts or oxides, and with lifeless animals and vegetable; causing them to rot and pass away in a gaseous form. Q. What is nitrogen ? A. Its chief office, probably, is to dilute the oxyger just as water is used to weaken intoxicating liquors.- The action of pure oxygen is too energetic. Wood an other combustibles, when set on fire and plunged into vessel of oxygen; burn up with astonishing rapidity, an living animals very soon die in it. Q. What else is there in the atmosjdiere ? A. Of course it contains all the gases produced b the combustion and decay of wood, &c., as well as a] those which are generated by the putrefaction of animak manures, &c. The odors of flowers, too, must be inclr ded. Q. What are the substances in plants and animals which, i decay and combustion, combine with oxygen and pass off i gases ? A. To answer this we must know something of thei constitution. You are aw r are that a large per cent, c Constitution of the Atmosphere , dee. 15 limal and vegetable matter is water. Well, if we cover ) in hot aslies a piece of flesh, some blood, some grains corn, or a portion of any other organized matter, and t it remain so for a considerable time, all the wafer will i driven off, and there will he left a black mass which 3 call charcoal. If, now, we set fire to this charcoal and b it burn up, there will he left a small quantity of ashes.* aat which is consumed is what chemists call carbon. It rites with oxygen and produces carbonic acid gas. Q. That is remarkable. How do you account for the color of >od if it consists of nothing but ashes, water and carbon ? A. That is. probably inexplicable. Sugar, cotton, irch and rice have the same constitution. Q. That makes the combustion of such substances a • simple Dcess. The oxygen combines with the carbon Only, producing L'bonic acid gas. Does carbon ever appear in the pure state ? A. Yes; the diamond is pure carbon, and black-lead plumbago is nearly pure carbon. Q. How can there be such a difference in tln^character of com- unds haying the same elements ? A. A difference in the proportion causes it. There e several compounds, however;, which have the same iments in the same proportion . Nine pounds of starch, t* example, are composed of five pounds of water and ur pounds of carbon; and the constitutution of cane gar is exactly the same. This fact enables us to understand why a yam potato comes sweeter after its removal from the earth. Its irch is gradually converted into sugar. Slow baking oduces the same result. It also enables us to understand why a grain of corn ows sweeter at the time of sprouting. Its starch is soluble, and cannot serve as food for the little plant; it God has wisely provided that it shall be converted to sugar, so as to become soluble ! The same is true of 1 cereals. This simple analysis must not be considered exhaustive ; heat drives oir other sub- nces besides water. 16 How Plants Grow. LESSON SIXTH. How Plants Grow. Q. If organized substances were to continue to decay, tlie would, after a wliile, use up, or combine with, all the oxygen of tl atmosphere, thus producing carbonic acid. Could we live in it ? A. No ; we must have oxygen. But you should h able to solve your own difficulty. The growing planl are continually employing carbon to build up their ow bodies. The carbonic acid is their food ; they absorb i through the pores in their leaves, separate the oxyge from the carbon, and the sap carries it where itisneede( The oxygen comes back into the atmosphere for us t breathe. Thus, you see, how beautifully, as well as wiseh the beneficent Creator has provided for the sustenance an comfort of His creatures. Q. . I thought the food of plants was taken in by the roots. - "What proof have you that your account is correct ? • A. There are some vines which will continue to gnr after they have been cut off from their roots ; I saw oni a cactus, or prickly pear, growing vigorously on top of stone wall, three feet high, where it had been placed foe or five years before ; a poor field, if properly managet will become more and more fertile, without any artifick application of manure. This, of course, is impossible if the earth furnishes the nourishment. Fence rows ai remarkable instances of this fact. They become ver , V fertile after a few years, although the land may have bee quite barren at the time the fence was laid. Q. But may not the carbonic acid be absorbed by the moistm of the soil, or be carried down by rains, and thus come within reac of the roots ? • A. I believe rain-water is not found to contain th: gas in any appreciable quantity. Indeed, water does nc appear to possess much affinity for it. If it did, a copioc shower of rain would leave very little of it in the atmo* phere. But the fact is, no amount of rain has ever cause any sensible diminution of carbonic acid in the atmo* phere. Moreover, we find little or none of it in the var: Nitrogen in Plants, and whence they obtain it. IT * * • us bodies of water on the earth, which, fact disproves the xistence of any affinity between them. It is true some prings are impregnated with this gas, but a little expo- ire to the'atmosphere soon rids them of it. Thus it is ot likely that any water carries carbonic acid to the Dots of plants. Q. Your reasoning seems conclusive against the admission of rge amounts of this gas by the roots of plants. Can you mention ly fact that denies the .admission of any at all ? A. You recollect that there is a constant flow of water ’om the great reservoir under us, lip to the surface, to ipply the loss by evaporation, and to bring up the otash, &c. 3 to the roots of the crops. It seems a phys- ;al impossibility that this water can carry any carbonic cid into the roots, because it has none to carry. This 3 beyond question , when the roots reach below the organic latter in the soil, as in the case of trees. LESSON SEVENTH.' Nitrogen in Plants , and whence they obtain it. Q. Are there no other elements in plants besides those you have lentioned ? A. Yes ; the nitrogen of the atmosphere is found in Dine parts of .plants. If you place some flour dough on piece of cotton cloth stretched over the mouth of a jar nd pour water to it, you will after awhile, by continually tirring and washing it, separate it into two parts. One >art will be starch and the other gluten. The starch, as told you, is composed of water and carbon. The gluten, fhich is a viscid substance, contains nitrogen. Q. Is there any general difference between those compounds ontaining nitrogen and the others ? A. The former undergo decay more readily, and pro- luce gases much more offensive. This explains the dif- erence between lean meat or muscle and fat meat. 18 Nitrogen in Plants , and ivhence they obtain U. Q. Does animal matter contain nitrogen too ? A. Yes ; and in a mucli larger proportion than vege^ table matter. Q. Well, now tell me liow plants obtain their nitrogen. Dc tlieir leaves drink it in from the atmosphere, as in the case of car¬ bonic acid ? A. This question is in considerable doubt, those who seem competent to consider it, differing widely in their opinions. In order to enable you to understand what is known about it, I will inform you that nitrogen occurs, in the earth and atmosphere, in two compounds, nitric acid and ammonia. Nitric acid is a compound of nitro¬ gen and oxygen, commonly called aquafortis. It is gen¬ erally found combined with potash, forming saltpeter.— In this state, of course, it can be absorbed by the roots of plants. Whether this is the fact, we will inquire after we describe ammonia. Ammonia is composed of nitrogen and hydrogen, (the gas which unites with oxygen to produce water,) and is commonly called hartshorn. It is a natural product ir the decay of all animal matter. You can smell it quite distinctly in horse stables, when the weather is warm. Q. If it is a gas, may it not enter into plants through then leaves ? A. The general impression is that rain washes it intc the earth where it comes 'in contact with the roots, but this is very doubtful. Q. If the rotting of manures produces ammonia, cannot the roots absorb it as fast as liberated ? A. Yes; but many crops grow where there ia nc manure—at least, animal manure—and, nevertheless, obtain their due share of nitrogen. Besides, repeated experiments have satisfied the leading Agricultural Chemists that certain crops have removed from the field twice as much nitrogen as was supplied in the manure, evidently some, if not all, of it came from the atmos¬ phere. . Johnston’s Agricultural Chemistry mentions a "act which leads to the belief that the atmosphere sup- Use of Manures. 19 plies ammonia directly to the leaves of plants. Sprengel states “ that it has very frequently been observed in Hol¬ stein that if, on an extent of level ground sown with wheat, some fields he marled, and others left unmarled, Hie wheat on the latter portions will grow less luxuriantly , and will yield a poorer crop than if the whole had been unmarled.” Q. How ? I do not understand you. A. It is impossible for the marled fields to lessen the amount of the nitrates, (saltpeter, &c.,) or of the salts of ammonia in the soil of the unmarled fields ; hut they can diminish the available nitrogen in the atmosphere. Q. How so ? A. The atmosphere sometimes stands nearly still over large districts of country for several hours, and even days. Under such circumstances the healthy and vigor¬ ous individuals of the vegetable kingdom appropriate much more than an average share of whatever food they find in it, and of course their less thrifty neglrbors suffer. I will mention another fact which confirms this .view : There is no nitrogen in mud, although it is one of our most valuable fertilizers, and often causes a crop of corn to he twice as rich in nitrogen as it would he otherwise. We will probably recur to this question after we inquire into the philosophy of manuring. LESSON EIGHTH. Use of Manures. Q. Well, really, I do not seetlie use of manures, if your account of the growth of plants is correct, unless it be to supply the atmos¬ phere with carbonic acid gas and ammonia, and for this purpose they might as well be in the stables as in the fields. What purpose do they serve ? A. Besides what you have mentioned, they keep the ground icarm. 20 Use of Manures. Q. Is that all we gain by hauling manure into our fields ? A. Very nearly. It is well known that plants grow more vigorously in warm than in cold climates. They require an elevated temperature which shall be constant .— In our latitude the sun heats the earth during the day. and radiation cools it during the night. To remedy this evil we incorporate with our soils a considerable portion of organic matter which, iq rotting, generates a uniformly elevated temperature. Q. Why does the rotting of manure create heat^? A. I have already told you that the combustion o: organic matter and the decay of it are, with scarcely ar exception, identical processes. The oxygen of the atmos¬ phere combines with its elements, producing heat in botl cases. Q. That is the cause, then, why heaps of manure become s< hot sometimes. I have often observed that when pulling up potatc sprouts the manure in the slip-bed was very warm. A. Yes ; and you had then a striking exemplification of the office of the manure. It makes the potatoes 01 slips sprout very rapidly, hut gives no nourishment to tin young plants, because they have no roots to receive it .— Moreover, we know that, in favorable weather, potatoes sprout even when lying on a dry plank floor. Q. Why are we so careful to rid our cornfields of grass ? Is i not because the grags extracts from the earth the nourishment w( intend for the corn ? A. Grass shades the land by day/and becomes so cool by radiation at night, that it reduces the temperature o: everything near it. In this way it injures land. If you) supposition were correct, one year’s growth of corn and grass together ought to exhaust the soil completely which is far from the truth. The experience of farmers confirms this explanation At the time when the ears begin to form on corn, and when, of course, it demands its most valuable nourish¬ ment, grass is alloived to grow. The reason is that th( summer is so far advanced, and the earth has become Lime , Marl and Ashes, dec. 21 arm to sucli a depth, that the radiation and shading of rass cannot injuriously lower the temperature of the iil. Q. Well, tliat.is remarkable. I have always had a very differ- Lt opinion. Do you really suppose that manure supplies no food the crop growing on it ? A. The rotting of organic matter, as said before, pro¬ ices carbonic acid and ammonia. These are both gases, id rise lip into the atmosphere as fast as generated. They ) not go downwards. If, therefore, the manure he spread 1 a field, the crop growing there will he continually en- doped in an atmosphere fully impregnated with these ises ; and, consequently, the plants will he able to ab- •rb, through their leaves, an abundance of food. LESSON NINTH. ime, Marl and Ashes. Animal and Vegetable Manures ; the difference between them. Bones, dec. Q. Why do persons put lime and ashes on their fields ? . A. Because they hasten the rotting of the organic atter in the soil, and thus increase its temperature.— his will enable *you to understand why many farmers ive become opposed to the use of lime, declaring that it jures land. It is because they have used it on fields hich contained very little organic matter ; in which ses, of course, the organic matter very soon decayed, id left the crops in the cold, at the most important period their growth. Q. Does not lime serve as food to the plants ? A. It is true, plants extract a small quantity of lime Din the soil, but on most lands they find as much as they jed, without an artificial supply. Q. A farmer, then, should not put lime or ashes on his land, less it is already well charged with organic matter ? A. No. The advantage of putting them on such land 22 Lime , Marl and Ashes , dec. is shown by the effect of the ashes produced by the bur ing of log and brush-heaps in our rich low-grounds. Q. How do these substances hasten the decay of organic matte A. In the present state of our knowledge that que tion is probably unanswerable. We simply know tl fact. tr • Q. Why is animal manure more active than vegetable manure A. Animal manure, such as we get from stables, ho pens, &c., is more energetic than mud; turf, leaves, stra &c., because it rots faster and generates more heat. Y< recollect that compounds containing nitrogen decay mo rapidly than those which are destitute of it. Q. Did you not state that nitrogen is found in plants as well in animals ? A. Yes ; but only in certain parts of plants. In t ordinary vegetation of our country nitrogen does e occur, except in the seeds. Q.. I see now the reason why it is bad policy to mix lime ashes with horse-stable manure : it is because it soon destroys \ animal matter out of it;—is it not ? A. Yes ; in that, as well as in cow, hog, sheep, go and hen manures, there is a large per cent, of nitrog compounds which, by their own readiness to-day, hast the rotting of the whole mass. Q. How do you explain that ? A. Probably by the abundance of heat which th impart to it ; but this is not certain. We may be unal to give the true cause. I have little doubt that electrici exerts a considerable influence in the case. Q. How do you account for the action of marl ? I have hes of numerous cases where marl applied to poor land enriched very much. Is there anything in it to rot and generate heat ? A. Yes; marl consists of the shells and remains innumerable animalcules. These in-sects have been lock' up from the atmosphere for thousands of years, probabl and could not rot, therefore. When the marl is spre* on a field and mixed with the soil it loses its tenacil and becomes sufficiently porous to allow the oxygen More about Nitrogen . 23 i atmosphere to come into contact with the animalcules. u*see, then, that marl can generate heat. ). Is not lime sometimes applied to marshy, “sour” places h good results ? A. In such places a large amount of vegetable acids vq been produced, which are injurious- to vegetation.— no combines with or destroys them, i. e., makes them 'ay. . v ). What effect have bones, superphosphate of lime, guano, &c., land. A. Bones consist of animal matter—“jelly, oil, &c.— :1 phosphate of lime, Guano is ‘composed of animal .tter, phosphate of lime, salts of potash and soda, and Lster of Paris. The action of the organic matter and 5 potash and soda needs no further explanation.,— .osphate of lime, plaster of Paris, and the inorganic rtion of marl, exert a stimulating influence; butprob- ly one effect of their application to land is simply to ninish its radiating power , so as to prevent it from ding rapidly at night. Some of the phosphate may ter into the plants. A plant does not require anything, then, but earth, air, heat 1 water ? A. Yes; the sun’s rays have a powerful influence on 3 vegetation of the earth, and as I intimated, probably ictricity is no less powerful. Plants cannot thrive in e dark. LESSON TENTH, More about Nitrogen. 1>. You promised to say more about nitrogen after you exam- d the philosophy of manuring. In Johnston’s Agricultural emistry* there is an account of an experiment made with nitrate soda, (soda-saltpeter,) in which it is shown that a wheat-field was y much benefited by a top-dressing of this salt. Is it not likely ,t some of this nitrogen served as nourishment for the wheat ? Edition or 1842 , 24 Sawdust, dc. Flow of Sap, dc. A. No ; this appears in a list of experiments, in whic it is also shown that common salt, similarly applied, 'pro diicecPa greater yield of wheat than the nitrate-of sod did; and you recollect that common salt is composed < chlorine and sodium. The difference of yieM was thre hundred and hoenty pounds of grain per acre in favor c the salt. Q. Yes ; but this wheat weighed only sixty-two pounds to tl bushel, While the other Weighed sixty-three. A. That is true ; hut there is a still more remarkabl fact exhibited in the same table : A mixture of salt an lime produced wheat which weighed sixty-three and half pounds per bushel. On the whole, therefore, I sup E ose the nitrates affect vegetation just as lime does, b astening the decay of organic matter, and lessening th radiating power of the soil. Q. Does not nitrate of soda, when put on grass land, or o helds of wheat, &c., as a top-dressing, cause the leaves to assume dark green color ? A. Yes ; but even then the yield of hay or grain less sometimes than on similar land where no nitrate applied. Q. How t do you explain the color ? A. I suppose the nitrate stimulates the vital principl of the plant to unusual activity in the preparation c coloring matter, just as intoxicating liquors arouse som men's combative dispositions. LESSON ELEVENTH. Sawdust , dec. Flow of Sap. Mode of Manuring . Dept * of Plowing , dc. Q. What is the action of pine straw and sawdust spread over a Irish potato patch ? .A. These substances prevent the sun from drying th soil and producing a hard crust on its surface. They als Sawdust , dc. Flow of Sap, dc. 25 revent heavy rains from packing the soil, and preserve a niform temperature. Q. Does sap rise in the Spring and descend in the Fall ? A. No; there is a continual circulation of sap, anal- ^ous.to that of the blood. It ascends through the inter or heart of a tree, and descends through the outer . arts near the bark. In its ascent, it carries the elements ? its ashes, obtained from the earth; in its descent, it irries the carbonic acid and ammonia, furnished through Le leaves. The case is the same with corn, wheat, &c. Q. Why is the hark of most trees loose in the Spring ? A. Because such trees add f to their size one layer per iar. This layer is commenced in the spring, and is at ’ rst nothing but a liquid. Being, of course, between the irk and the solid wood, the former can be easily peeled F. . • Q. Why will a green water melon ripen rapidly, if we cover it > with earth ? A. Because the rind performs the same office that aves do. It extracts from the atmosphere the required mrishment. When buried, therefore, this action ceases id the vital power of the melon directs its energies to e maturing of the materials on hand—ripens it. Q. How deep should we put manure ? A. If we place it on top of the ground, it will soon come dry, (stable manure,) in which case it cannot adily decay ; and if it should, its heat cannot descend r into the earth. Consequently the corn roots will stay sar the surface where it is warm, and if there be much y weather they will suffer for water. !}. Why cannot the heat descend ? A. Because the earth is a bad conductor, and the up- ird current of water has a tendency to make the surface cool as itself. This is proved by the limited depth to rich the heat of very large fires warm the ground. If we place the manure very deep in the earth, so that e atmosphere cannot come into contact with it, it cannot • _ 26 Sawdust , dtc. Floiv of Saji, &'c. rot, and will be useless. The depth at which it shou be.put depends on your mode of plowing. Q. Why so ? A. All the manure below the furrow which yo plow makes, and which is left undisturbed, does little no good, because the oxygen cannot penetrate it and cau it to decay. Q. Do you think we should stick the plow in as far down the manure extends every time we plow ? A. No; one such plowing every Spring, just befo planting, is sufficient. To obtain the best results, I shou thoroughly incorporate my soil with manure to the dep of fifteen inches, at least. To do this, I should spread < say one hundred ox-loads to the acre and plow it in, ai should repeat the operation as often as possible. Afl the soil should become as fertile as I could make it should lessen the dose of manure, but not the depth the plowing. Q. Would it not do to apply a sufficient amount at once ? A. Not so well, if it were farm-yard manure, would be difficult to mix it thoroughly with the soil, ai the heat generated by it would not be uniformly distri uted. Besides, I should be afraid there would be t much heat, and my crop would get u fired,” as the far] ers term it. Q. Suppose you liad mud or turf ? A. In that case it would be better to plow in a fi supply at once. Q. If, in the Spring, you should cover up an ordinary coat manure with fifteen inches of earth, you would render the la useless. The surface would be barren sand or clay, and the atm phere would never reach the manure. A. That is very true. I would not treat my whc farm in that way at once, unless I could repeat the of ration before planting, and very few farmers can fu time and manure to do this. It would be better to ta' a small piece of ground at a time. I could do this whe ever I should have the manure ready and time to spai 21 Fermentation. Compost Heaps^ dec. • v/ would not require many years to prepare, in this way, many acres as I should need. If you used mud would it not be necessary to add a little le every Spring ? A. Yes ; unless I had farm-yard manure enough.— )u recollect *tliat I told you that animal matter rots ach faster than vegetable matter, and when mingled th mud it would serve the same purpose as lime. . LESSON TWELFTH. Fermentation. Compost Heaps . Lamp-black , dec. Q. Why do farmers wait for compost heaps to ferment before ing them.? A. Because fermentation is a rapid decay which dis- tegrates or pulverizes the solid matter of the heap. Q. What causes this rapid decay ? A. It is caused by the rotting of the nitrogenized bstances—generally animal matter. Q. Does all the animal matter rot, then ? A. That depends on the length of time the process is lowed to go on. If it continues Till the heap begins to ol, it is quite certain that the nitrogenized compounds 1 decay. Q; The ammonia is all gone then, is it not ? A. Certainly; and the heap is pure vegetable matter. Q. What is the advantage of having the solid substances pul- rized ? A. They can be uniformly disseminated through the il, and can decay more easily. Q. How can they decay more easily ? A. More surface will be exposed to the action of oxy- sn ; just as a pound of clean iron-filings' can become ,st much sooner than a pound of the same metal in one 28 Fermentation. Compost -Heaps , do .. Q. You have conveyed the idea all along that no substam simple or compound, found in our ordinary manures, can prod as much heat as those compounds containing nitrogen. Is that A. No. Heaps of oily rags or cotton sometimes ; sorb oxygen and become so hot as to blaze. The sa is true of mixtures of linseed oil and lamp-black, if i proportion of oil is small or the mass is dry. Q. What is lamp-black ? A. When wood is burning in our fireplaces, a sm quantity of the carbon rises in a gaseouk state, and me no oxygen until it has become too cold to unite with Consequently it passes away in the smoke or lodges the walls of the chimney. This is lamp-black. Q. Could these substances be made available as manures ? A. Lamp-black and pounded charcoal have been m to great advantage on grass lands. Experiments nr tioned by Johnston show that while salt caused an crease of one ton per acre in the hay grown on a cerk farm, soot caused an increase of eighteen hundred weig and nitrate of soda caused an increase of twelve-hi dred weight. They were used as top-dressings, May ! Thus you see soot is a better fertilizer than the nitrate soda. Q.- Do you think the advantage resulted from the decay of soot, or from its covering the soil and preventing the escape heat ? A. Probably from both. Q. What causes cotton seed to ferment when composted w leaves, turf, &c. ? A. The analysis of cotton seed shows that nearly oi fourth of their substance consists of nitrogen compoun They contain, also, nearly ten per cent, of oil. It is nr likely, therefore, that their fermentation is the result the conjoint operation of both the causes mentioned 1 fore. Q. Is it better to make compost heaps with cotton seed, spread and plow them into the soil ? A. That depends on the condition of the soil. Sand, Clay , dc. 29 ucli larger amount of manure can be prepared by ma¬ tt g the heaps, and I think the seed can be rendered ere serviceable in this way. If, however, a field were ell supplied already with vegetable matter, especially ud, it would be better to plow them into it. Q. Are there other seeds which could be used in a similar inner ? . . A. .‘Yes ; if we had enough of them. LESSON THIRTEENTH. md, Clay , dc. More about Compost Heaps. Top - Dressing. • v • , • » Q. Why does sand put on stiff mud land improve it ? A. The soil is rendered porous, so that the water slow can escape through it, and the oxygen can readily metrate it. Moreover, corn grown on mud has weak alks and is easily blown down. You recollect I told )u that the strength of the stems and leaves of corn, ^ass, &c., depends on the sand in their composition. Q. Does not the addition of clay often benefit sandy soils ? A. Yes ; sandy kind is too porous, generally. It al- ws too much evaporation of moisture, which tends to >ol it; and oxygen can penetrate it so freely that no ’ganic matter can remain in it long. It soon rots out. he application of clay remedies these’evils; and the ime may be said of any other tenacious substances, as iarl, plaster, &c. • . Q. Might not sand'benefit stiff clay land on the reverse prim pie?. . * * • A. Undoubtedly. If such lands, however, were well barged with organic matter, that would render it light- nd porous. Q. What other substances are found on our farms which could e made available as fertilizers, besides those you have already pokeu of ? 30 Bandy Clay, dec. A. One of the most valuable of all manures is night soil; because, containing a very great amount of nitro genous matter; it can be used in compost heaps whei the vegetable matter is largely in excess of the usua proportion. The carcasses of dead animals, the blooc of butcher pens, spoiled fish, &c., &c., are equally val liable. • Q. How would yon apply tliese substances ? A. I should first compost them with leaves, straw cornstalks, and any other convenient vegetable matter under a shed, which could keep off both sunshine an< rain. Q. Why exclude them ? A. Because the sun would drive out the moistur without which nothing can rot ; and the rain would dis solve and wash down many substances essential to thi fermentation. Q. In making these heaps what sort of vegetable matter wouL you use ? „ A. Leaves, straw, cornstalks, &c. Q. Would you not employ mud ? ... A. No; the object of such heaps is to pulverize or ganic matter, and mud is already pulverized. Q. Why is it so cold, then ? ... A. Because the amount of water in it is so great tha oxygen cannot penetrate it, and even if it could, the cool •ing effect of excessive evaporation would prevent am great elevation of temperature. Spread on a field anc intimately mixed with the soil, it ceases to be cold. - Q. What is mud ? A. It is little else than charcoal. In some countrie; it serves for fuel. Q. When would you haul out and plow in the compost heaps ? A. Just before planting corn, and, if possible, I shoulc endeavor to arrange for the fermentation to be still pro' grossing. Q. Why so ? Sandy Clay , &:c. 31 A. Because the heat generated in the soil would asten the germination of the corn, and give the young lants a good start by the time the summer heat could elieve that of the fermentation. Q. Did you not say tlie sun’s heat is not sufficiently uniform )r the purposes of vegetation ? A. For cultivated plants, I meant; but, of course, the arth grows warmer as Spring advances. Q. You make a distinction between the heat of fermentation and rat caused by the rotting of pure vegetable matter , as leaves and fcraw ? A. Yes ; the latter is more uniform. Q. Would such manure improve wheat land ? A. My impression is that ft would not. If put on ast before planting, the heat of fermentation would cause rapid germination of the seeds ; but all the nitrogen- us compounds would be exhausted before Spring ; thus he transition from a very warm to a comparatively cold oil would, no doubt, injure wheat. Q. Does the experience of farmers accord with this view ? A. I am not informed.' Q. Suppose the fermentation were completed, might not an plication of such manure be beneficial ? A. Of course. In that case the decay of the organic latter would be uniform. Q. Could we not hasten that decay early in Spring by top- ressings ? A. Yes ; a coat of plaster, common salt, marl, leached shes, soot or pulverized charcoal would answer this pur- ose. Q. Why not lime or unleaclied ashes ? You said they were very owerful in hastening the decay of organic matter. A. True; but you must remember the young wheat 5 organic matter. Besides, too sudden an elevation of 3mperature would do more harm than good. Q. Which of the substances enumerated do you think the best? A. No one of them would be best for all lands. So ir as experiments show, common salt appears to be the 32 Sand, Clay , dec. best on heavy loam. I should prefer something less sol¬ uble, as marl or plaster,, on sandy land. It is to he re¬ gretted, however, that our people have never adopted any general system of experimenting, and we are sadl} in the dark in regard to this important question. Q. Ought not every farmer to make his own experiments ? A. It would, no doubt, he better. An acre of ground well supplied with organic matter, could be sown in wheal at the proper time, and early in the Spring, say from the 1st to the 15tli of April, it could be divided into lots ac¬ cording to the number of stimulants intended to be ap¬ plied. . Q. How much salt would you put on an acre ? A. Experiment could give the best answer. The lol intended for salt could be subdivided into several parcek and a different quantity of salt applied to each. In this way a farmer could gain most important knowledge, in one year, at a very trifling cost. Q. Is there no animal substance that could be employed as ( top-dressing ? A. Yes ; dried blood, the dried manure from poultr} yards, &c., &c., would be valuable ; but they would have to be in powder, and there would be danger of applying too much. They should be used with caution. Q. Might not guano serve a good purpose as a top-dressing ? A. Undoubtedly ; and so might lime, if it were mixed with some substance which would prevent it from coming in direct contact with the tender parts of the young plants. Q. Why is liorse-stable manure better than cow-pen manure ? A. Because the former contains a much larger pei cent, of nitrogenous compounds, and consequently gen¬ erates more heat, . . Q. Why is cow-pen manure better for turnips ? A. Because turnips do not require a very warm soil: and there may be other reasons. Green Manures. Commercial Fertilizers , dc. 33 LESSON FOURTEENTH-. Green Manures . Commercial Fertilizers , dc. Are not green crops sometimes plowed in as manure ? A. Yes ; for small grain particularly. Peas are prob- ly the most valuable crop among us for this purpose ; :hougli I am inclined to the opinion that crab-grass, in dricts where it thrives, can be made to serve as good a rpose, at less cost. *). How could you get seed enough ? A. I should need none. The earth preserves an undance of seed, as is proved by the trouble farmers ve in ridding their crops of this grass. ' What would be necessary for you to do ? A. Simply to give the land intended for wheat a thor- gh plowing in the Spring, so as to insure a good coat grass during the Summer. Why will not these green crops do as well if allowed to ripen l become dry ? A. They will not decay so readily. How deep would you cover a green crop ? A. Not very deep. I should be governed by the depth which the roots of wheat extend. }. Can this mode of manuring be adopted with advantage for n ? * • . A. That would depend on the accessibility of mud. pea crop might cost more than ah equal amount of or- nic' matter supplied in mud. }. Do not peas contain nitrogenous substances ? A. Yes ; but these would complete their fermentation fore they could be serviceable to corn. j). Would you advise the use of commercial fertilizers ? A. There are few crops grown on our farms which are t also consumed on them. The potash, lime, magnesia, la, phosphorus and sulphur removed from the soil are, jrefore, not carried off, and can be readily'restored to ) fields whence they were extracted. Cotton, it is true, 34 Green Manures. Commercial Fertilizers , &c. when grown for market, -carries off a small per cent, these substances,—nearly one pound in a hundred; bi this loss, on the farms in Eastern Carolina, where tl land is light, would not be felt in a century, or probah in thousands of years. It must not be forgotten, to that the soap, salt, lime, copperas, &c., brought on 01 farms, return to them many of the inorganic elements which crops deprive them. I think, therefore, every farr er can find materials on his own land for manuring pu poses. • * . Q. Suppose he cultivated wheat for market ? A. In that case it would be necessary to make pr vision for the salts carried off by the grains. The stra' of course, should be composted and returned to- the fie whenee it came; because its ashes contain much potai and phosphorus. The grains contain very little inorganic matter, t produce of one acre yielding, on combustion, not mo than ten or twelve pounds of potash, soda and magnesi and not more than twelve ounces of lime. Here I will mention a remarkable fact and one tendii to confirm the views I have already expressed. Gypsum, or plaster of Paris, bone dust and lime do n contain any magnesia ; they consist principally of lir of which wheat grains require very little. Neverthelc they are the most common fertilizers for wheat' land.- The supply of magnesia must, therefore, come from t earth ; four pounds to the acre. Q. Your opinion is that, if an acre of land can yield annua four pounds .magnesia , for an indefinite term of years, without bei artificially replenished, it ought, also, to yield the small quant: of twelve ounces of. lime ? A. Yes ; especially since we know that many fiel have been annually deprived of a much larger proportic of lime, for scores of years, without showing the lea sign of exhaustion. Q. You would discourage the employment of commercial m nures, then ? Preparation of Manures. 35 L Yes, if intended to serve as food for the plants. I nld not object to their employment as top-dressings or :ompost heaps to hasten the decay of vegetable matter, m convinced, however, that even for these purposes, ry plantation furnishes abundant materials. LESSON FIFTEENTH. * * Preparation of Manures . . How would you obtain the largest amount of manure from animals on your farm ? . * . L I should erect good stables, one for each, into ich sunshine and rain could never enter. If possible, floors should he water-proof and about ten inches of walls, also, from the floors upwards. 'nto these I should spread, every week or fortnight, ves or straw enough to cover the excrements accumu- 3 d in that time. \.t the end of every two or three months I should re- ve all the manure from the stables and place it in heaps convenient size, under 1 sheds so situated as to he pro- ted from the winds as much as possible. >. You would have no open lots, then ? A. No. In such places the sun dries manure, and n cools it. ). Would not your plan consume too much time ? A. Not at all. Every farmer has spare time enough such work, and habit would soon render it easy and ivenient. y Would you throw soap suds and ashes on these heaps ? A. No. * They would check fermentation by a sudden struction of the nitrogenous matter. Lime would do 3 same. That reminds me of a question which has been puzzling me for ae time : How does salt, as a top-dressing, hasten the decay of B6 Ploughing , Ptarrowing , do. Vegetable matter in the soil ? Did you not say that salt is a co: pound of chlorine and sodium ? A. How salt causes the oxygen- to combine more e ergetically with vegetable matter, is a question I a unable to answer. We know that a piece of iron w rust much faster when occasionally moistened with sa water than it will if the water be fresh. The cause this is unknown to us ; but whatever it is, it is doubtk the same as in the other case. LESSON SIXTEENTH. Ploughing ; Harrowingj do. *• , t j? • Q. I think I understand your theory of the action of nlanur Now tell me how often and how deep you would plow your cc land after planting ? A. After preparing mj land by manuring and pulvc izing to. the depth of fifteen inches, I would plant u corn. The soil would then be sufficiently porous for t' oxygen to penetrate it to its lowest depths ; and the gas generated by its decay would maintain it in its poro state. ■ No more deep plowing would be necessary. Q.- If that be-true, no more plowing at all would be required. A. Yes ; you recollect there is a crust formed on t verized. • Q. That crust is seldom over a half-inch thick, and can be bi ken by something lighter than a plow ? A. Yes ; I should use a broad harrow, which cou pulverize a whole row by going up and down once. I so doing I could go over my whole crop in less than lis the usual time, and would scarcely fatigue my horse. Q. You would leave, in this way, a portion of grass between t hills of corn undisturbed. ‘ A. True, but the time gained in harrowing wou fully suffice for weeding this out with a hoe. Even Advantages of Improved Modes of Cultivation , dec, 37 • r * is were not done, tlie advantage of the liarrowing is >ry great, when we consider that the last rows of a crop inerally suffer much before the plow can get to them. Q. Do not heavy rains beat down the surface of the earth and us lessen its porosity ? A. Yes, and, of course, the crust thus formed needs ilverizing ; but the harrow will suit just as well as in e other case. 3- How often would you harrow your fields ? A. Every time the surface should become encrusted. LESSON SEVENTEENTH. Ivantages of Improved Modes of Cultivation, Cotton- Space between Bows , dec . If farmers were to adopt this mode of cultivating their L ds, what would be the increase per acre ? A. Instead of one or two barrels they would gather >m eighteen to. twenty-three. Twenty-three ! . A. Yes; some years ago two gentlemen of Nevvbern a contest of agricultural skill, gathered that much per re, one of them exceeding it by a tub-full or two. Many nilar cases are reported in the newspapers. If all our lands were improved to that extent, every farmer ild dispense with about nine-tenths of his present enclosure. A. Yes, and thus save an immense deal of labor in icing, ditching, hauling, plowing, harvesting, manur- y, &c., &c. He would save time in every conceivable partment of his business, and, of course, could pay the ire attention to his manures. At the end of the year g horses, his gear and his plows would be in good con-, bion ; his barn full to the joists, and his smoke-house 3 ming with its abundance of meat and lard. 5 . Would you apply the same mode of culture to cotton Z A. Substantially the same. 38 pitching. % Q. Does the produce of a crop depend, to any degree, on tl direction of the rows ? A. Very likely. If the rows lie North and South, i drilled corn, the sun's rays do not reach the earth, hut short time at noon, after the plants become.nearly grown hut if -they lie East and West, the sun can shine on tl ground.twice every day, at about ten and two o'clock, ar a good while each time. Q. What* space would you allow between corn rows and 1 tween the hills in a row ? A. Four feet between rows, and one foot between hi! Thus I could put ten thousand seven hundred and sixt four plants on one acre. Q. Might not the rows be placed farther apart and the stal nearer together with advantage ? A. That would depend on the character of the so and experiments made with one crop could • determ! that question for any farm. Q. What do you mean by the “ character of .the soil ?” A. I have reference particularly to its capacity to i tain moisture, and consequently to its natural temperatei Q. Some.farmers are careful in choosing seed corn. Do y think it is worth the trouble ? A. Certainly. Everything that grows partakes mo or less 01 the vigor and perfection of the seed from whi< it springs. A farmer should gather the largest ears from tho stalks which are the most fruitful, and carefully preser them for seed. LESSON EIGHTEENTH. . Ditching. Q. Why are ditches necessary ? A. Because cultivated plants, with few excepti'or cannot thrive with their roots in standing water; an besides, when the soil is sobbed with water,, oxygen ca: Resting Land. 3£ it penetrate it with sufficient ease, and excessive, evapo- tion diminishes its temperature. Q. What causes certain localities to be too wet ? A. In some places the impervious stratum , before- entioned, is shaped like a sauccer, so that the rain iter which soaks down to it cannot escape. When it gets 11, therefore, and its surface coincides with that of the rth, the soil is too wet. A ditch dug from the center of this saucer, in any co-n- nient direction, so as to cut through its side, will drain, e land. In most instances, however, dampness is caused by a fference in the inclinations of the surface and the water- d. The water, in following the slope of the latter, mes to the surface long before reaching a place where can readily escape. Q. How would you remedy this ? A. By a ditch cut at right angles to the direction of e slope and above the places where the water first comes the surface. Q. How deep should the ditch be, and where would you have it empty itself ? A. It should be dug entirely through the upper stra¬ in and extended from its lower extremity to a suitable vine or other ditch. LESSON NINETEENTH. Resting Land. Q. Why does resting land improve it ? A. There are two reasons : 1st. The grass and weeds hich grow on a rested field are a valuable addition to 3 elements of fertility. '2d. Crab-grass and other weeds * quick growth, are much less troublesome after a year’s ist, • 40 Besting Land. Q. How do you account for the latter fact ? A. Crab-grass does not thrive on uncultivated land It requires the soil to be stirred occasionally. Conse¬ quently there is less of its seed on the ground, after a year’s rest.