THE FARMER'S MONTHLY VISITOR. 



March, 1842. 



The linmus in the soil will give oulits carbonic 

 acid, until the plant rises aljove the ground, and 

 the leaves and other portions of its organism are 

 formed to enable it to irather, in the form of car- 

 bonic acid, its food tioni the air. Its organic con- 

 stituents must be found in the soil or in the 

 manure in the form of silicates, carbonates, or 

 phosphates, and may be supplied in a'crude form 

 as in potash, nshes, lime, bones, &c. Its nitrogen 

 is to be supplied, in the form of ammonia, from 

 decayed animal or vegetable substances in one 

 way or another. The excrements of some ani- 

 mals are in this respect much richer than those 

 of others. The excrements of man are much 

 richer in nitrogen, tlian those of any other ani- 

 mals, and those of men living upon animal more 

 so than those of men living upon vegetable diet. 

 lu the urine of aninjais nitrogen is found in much 

 greater abundance than in the solid excrements. 

 In respect to nitrogen, 100 parts of the urine of 

 a healthy man are equal to 1300 parts of the fresh 

 dung ot' a horse. This ammonia is supplied m 

 the soil ; or floating in the air, it is taken up by 

 rain water or by snow, and supplied to the vege- 

 tation in that form. The manures of difTerent 

 anitnals likewise return to the soil the inorganic 

 constituents of plant.s, the various salts which 

 have formed a part of the vegetable products, 

 which have been taken from the fields and been 

 consumed by the cattle; and thus every thing 

 goes on in an 'eternal round of reciprocity. 



I have thus given a general and imperfect 

 sketch of the main principles of the work of Lie- 

 big. I have confined myself to the part, which 

 is principally agricultural. The second part, on 

 chemical transformations, fermentation, putrifac- 

 tion, decay,-and various kindred subjects, is equal- 

 ly interesting. The work of Liebig displays ex- 

 traordinary philosophical acumen, and confers 

 upon him the highest honor. The more it is ex- 

 amined, the deeper will be the interest which it 

 will create, and the stronger the admiration of 

 the ability with which it is written. It is not a 

 work to be merely read, but studied ; and if fur- 

 ther inquiries and experiments should demon- 

 strate, as seems to ns from many facts within our 

 own knowledge in the highest degree probable, 

 the soundness of his views, his work, not merely 

 as a matter of interesting philosophical inquiry, 

 but of the highest practical utility, will be inval- 

 uable. 



There are various notes, appended to the vol- 

 ume, of great interest. A long and highly inter- 

 esting note is appended, containing some letters 

 from Dr. S. L. Dana, of Lowell, to Dr. Hitchcock, 

 of Amherst College, and taken from the forth- 

 coming third edition of Dr. Hitchcock's "Geolo- 

 gy of Massachusetts," on geine or hmnus, and 

 some views of Dr. C. T. Jackson, of Boston, on 

 the same subject. 



The views of these gentlemen in some mea- 

 sure conflict with each other, and with those of 

 Liebig. I shall not presume to arbitrate between 

 them, but only to remark on them, in a very [ew 

 words, with a perfect respect for all the parties 

 concerned. The eminent Swedish chemist, Ber- 

 zelins, had discovered in ."several vegetable sub- 

 stances, a residuum, which he regar<led as the 

 proper food or pabulum of vegetables, and which 

 iie denominated humus or geine. Dr..Dana, by 

 his independent Tesearches, had arrived at the 

 same result. This geine or apntheme was found 

 to be the universal result of d.cayed vegetation; 

 and soils are in general found productive or 

 otherwise, as this vegetable substance or residu- 

 um is more or less abundant in them. The opin- 

 ion of Dr. Dana has been thatgoinein a dissolved 

 state is taken up as the food of plants. If obliged 

 to relinquish this ground, and with Liebig, re- 

 gard geine as only a .source of carbonic acid to 

 ])lants. he would regard its value to vegetation in 

 the same light. But he obvi;ites in a most in- 

 genious manner one of the difficidties of Liebig, 

 in respect to the sohihilit;,, or, we may more pro- 

 perly say, the solution ot'geine, by showing that 

 it contain?! within itself the insti-ument, tr> a con- 

 siderable degree, of its own resolution, in the 

 water forin«d by the union of the hydrogen of 

 the geinn with the oxygen of the atmosphere. 

 " The amount of water produced in this case," he 

 remarks, "is truly astonishing. It has been found 

 equal per hour, fiom an acre of fresh ploughed 

 sward» to f).50 lbs. This is equal to the evapora- 

 tion per hour from an acre, after most copious 

 ■ains To show that this denpiids upon the de- 



composition of the geine, the quantity of water 

 evaporated per hour in the day-time, from a well- 

 mamu-ed acre, was found eijual to 5000 lbs." 



That humus or geine does not constitute the 

 actual food of plants, would seem to be estab- 

 lished by various considerations. Liebig has 

 shown by several calculations, as exact as the na- 

 ture of the case would seem to admit of, that the 

 amomit of hunfic acid contained in any soil is 

 insufficient to supply the carbon in the average 

 product of that soil, in the proportion of 91 to 

 2,650. Secondly, volcanic soils containing not 

 the slightest trace of vegetable matter, as is e»i- 

 dent fiom their origin, with a due nfixture of 

 earths, are among the most fertile in the world. 

 The ashes being exposed to air and moisture, a 

 soil is gradually formed, and the decomposed 

 lavas furnish alkalies in abundance, which, by 

 being exposed to air and moisture, become the 

 source of rich nourishment to plants. A third 

 reason, and certainly a strong fact in the case, is 

 that the humus in a forest, so far from being di- 

 nfmislied by the growth of wood, is continiially 

 increasing. It is so likewise in a cultivated fiehi, 

 where the produce of the field is returned in the 

 formof manure. 



Berzelius is reported to have altered his opin- 

 ions of the nature of geine by a more exact anal- 

 ysis of its composition, and now denies its exis- 

 tence as a proximate principle ; and Dr. C. T. 

 Jackson, who has distinguishetl himself as a 

 chemist by his analytical researches, appears to 

 have made, without knowing what had been 

 done by Beizelius, the same discoveries!, in ascer- 

 taining that the substance called geine is only a 

 combination of crenic and apocrenic acids, with 

 some other substances, all of which are not yet 

 determined. How many of these may have been, 

 as suggested by Dr. Dana, the mere product of 

 chemical manipulation, or whether any of them, 

 are questions which, iu the present state of the 

 inquiry, cannot be determined. Upon the sup- 

 position that these are original and fixed ele- 

 ments in the composition of geine, we consider 

 Dr. Jackson entilhsd to nnich honor for his inves- 

 tigations. All truth is valuable ; but in the pres- 

 entcondition of our knowledge,in a practical view, 

 these points arc not of great importance, or rath- 

 er not of immediate utility. According to the 

 principles of Liebig, Raspail, Dana, Jackson, 

 Hitchcock, and others, the presence of humus in 

 a soil is, quoad hoc, an indication of fertility. 

 Now, whetiier it be a proximate element, or a 

 mere combination of crenic and apocrenic acids 

 with other substances, though exceedingly inter- 

 esting to the philosophical inquirer, is, without 

 some further light on the subject, of little mo- 

 ment to the farmer. Dr. Jackson has not, as we 

 understand, discovered either of these acids in 

 the lilants themselves ; he has not as yet shown 

 us how they are to be used, or what part they 

 perform in "vegetation. — He is not able, by any ar- 

 tificial process which he can adopt, separate from 

 the vegetable organism, to prot'luce an atom of 

 geine; and however nearly he may have ap- 

 proached it, and we commend him for every step 

 in his progress,he has by no means reached the ul- 

 tima ihule, for crenic, and apocrenic; anil ulmic 

 acids, are themselves resolvable into certain por- 

 tions of carbon, hydrogen, nitrogen and ox- 

 ygen. The question however, whether geine 

 constitutes iu itself the food of plants in its 

 solution by water or by some alkahne sub- 

 stance, or whether it merely acts as an instru- 

 ment of the supply of carbonic acid to the 

 [ilaiit in the first stages of its progress, is another 

 question which is certainly not Ivithout its difli- 

 ciihics. 



lam not able to understand by what process 

 it is ascertained, that, after the leaves of the plant 

 are fornietL it ceases to draw any nourishment 

 from tlifTe.-Ji-th. This is a fact in vegetable physi- 

 ology, of v^Tii'h at present- we are without the 

 proof Dr. Dana has never denied that jilants 

 receive much of their nourishment from the air. 

 His inquiries were limited wholly to what they 

 gather from the earth. Nor is there nnydiflicul- 

 ty in the supposition that geine may serve, in its 

 decomposition, as the food of plants. For, if geine 

 according to Dr. Jackson, is a mixture of crenic 

 or apocrenic acids, and if crenic and apocrenic 

 acids are resolvable into carbon, hydrogen, nitro- 

 gen, and oxygen, these are the very elements of 

 vegetable substance ; and we may leave it to the 

 subtile operations of the vital action, wonderful 



and mysterious as it is in its operations, to ac- 

 complish what human skill and sagacity have as 

 yet iu vain essayed, the separation and appropri- 

 ation to itself, by the living plant or animal, of 

 the proper materials of its own growth. 



It is exceedingly gratifying to see men of sci- 

 ence engaging in these, I will not say humble, for 

 scarcely any are more important, but useful sub- 

 jects of investigation. Every department of nature 

 abounds in matters of interesting inquiry ; and 

 none more than that of organic life. Nature iu 

 her various changes, transformations, and pro- 

 ductions, is everywhere full of the miracles of 

 wisdom, power and goodness. The perfections 

 of the Creator are written all over her in letters 

 of living light. The highest duty of rational be- 

 ings is " to read, mark, learn, and inwardly digest 

 them." 



In looking at the infinitely multiplied produc- 

 tions of the vegetable w;orld, iu observing a small 

 seed rising into a towering plant, an acorn chang- 

 ed into an oak, and what .seems a pellicle, driven 

 about by the wind, growing up into a wide 

 spreading elm, we must be lower than the beasts 

 which repose under its grateful shade, if we do 

 not ask. How do these things come.' When 

 vveseethe earth in a measure obedient to our 

 commands, and in return for our labor pouring 

 into our lap the means of subsistence and luxury 

 with an unstinted liberality ; when we see the 

 dependence everywhere existing between what 

 wo do and what we receive, what we sow and 

 the harvest we gather; when we observe the 

 changes of the seasons, and the obvious effects of 

 lightand heat, and moisture and manure, wo can 

 hardly claim the character of rational beings, if 

 we do not seek to understand these thing.s. It is 

 idle to pretend that the mysteries of nature are too 

 sacred for inquiry. The gifV of understanding 

 and the power of its use imply Ihe duty of inqui- 

 ry. It is as idle to pretend, that they are mys- 

 teries which never can be understood. The hu- 

 man understanding has its limits, doubtless, be- 

 yond which it cannot pass ; but how far is it at 

 present from having reached them .' Every day 

 is disclosing to ns some new truth. Mauy things, 

 once enveloped in all the terrors of mystery, are 

 now fiimiliar to the understanding of a child. 

 The works of God and the courses of his provi- 

 dence, are not so many isolated facts, but they are 

 facta compacted together, and under the control 

 of general laws ; so that, beyond all question, 

 many of the most extraordinary phenomena, 

 which present themselves in nature, are explica- 

 ble upon the simplest principles. In many cases 

 a single key will open the most complicated lock, 

 and is at the same time applicable to a thousand 

 other.s. Tlie discussions of Liebig fm-nish some 

 beautiful illustrations of these principles. 



In order to solve the secrets of vegetable life 

 and growth, we must watch the plant from its 

 germination to its maturity, and remark, with all 

 possible exactness, the various influences which 

 bear upon it. We must study its nature, its re- 

 lations, its changes ; its relations to the soil, to 

 the climate, to the light, to the moisture, and to 

 its whole culture. Botany, considered as a mere 

 form of classes and a mere catalogue of arbitra- 

 ry names, is a meagre and comparatively worth- 

 less science ; but when it involves the whole 

 physiology of plants in all their aspects and con- 

 ditions, in their growth, culture, maturity, and 

 use.s, it becomes a profound philosophy. Chem- 

 istry, likewise, must here come to our aid. In 

 otdertoknow wliat the plant needs, we must 

 know what it is composed of; in order to learn 

 what it obtains from the soil, we must ascertain 

 what the soil has to yield to it ; nnd we must 

 consider the condition of the iilant, in reference 

 to the condition of the soil in which it is planted. 

 Manures, likewise, everywhere the acknowledg- 

 ed means of fertility, require the most exact ex- 

 amination. Ascertaining, by the aid of chemical 

 inquiry, the elements of the plant, wo shnll at 

 least learn something of what it requires; ascer- 

 taining the nature of the soil, we shall see how 

 it is suited to the plant cultivated ; and knowing 

 the composition of the manures, we may como to 

 gnder,statid their operations. Chemical analysis 

 seems to offer the only means of solving these 

 mysteries. 



It has already made distinguished advances; 

 but yet they can be regarded only as first steps. 

 There are difficulties in the case, "which it would 

 be in vain to deny. All chemical analyses are 



