468 



THE FARMERS' REGISTER. 



little is yet known on this subject, and it offers a 

 fertile field for investij^ation to agricultural^ che- 

 mists and scientific agriculturists. Liebigs re- 

 marks on these elements of plants supplied from 

 inorganic nature, present less of what is either 

 new or important than the other branches of his 

 researches. 



"Most plants, perriaps all of them, contain organic 

 acids of very different composition and properties, 

 all of which are in combination with bases, such as 

 potash, soda, lime or magnesia." — (p. 148.) 



"The acids found in the different families of plants 

 are of various kinds ; it cannot be supposed that their 

 presence and peculiarities are the result of accident. 

 The fumaric and oxalic acids in the liverwort, the 

 kinovic acid in the C/iiiia nova, the rocellic acid in the 

 Rocella thictoria, the tartaric acid in grapes, and the 

 numerous other organic acids, must serve some end 

 in vegetable life. But if these acids constantly exist 

 in vegetables, and are necessary to their life, which 

 is incontestable, it is equally certain that some alkaline 

 base is also indispensable in order to enter into com- 

 bination with the acids which are always found in the 

 state of salts. All plants yield by incineration ashes 

 containing carbonic acid ; all therefore must contain 

 salts of an organic acid. 



" Now, as we know the capacity of saturation of 

 organic acids to be unchanging, it follows that the 

 quantity of the bases united with them cannot vary, 

 and for this reason the latter substances ought to be 

 considered with the strictest attention both by the 

 agriculturist and physiologist. 



" We have no reason to believe that a plant in a con- 

 dition of free and unimpeded growth produces more 

 of its peculiar acids than it requires for its own exist- 

 ence ; hence, a ])lant, on whatever soil it grows, 

 must contain an invariable quantity of alkaline bases. 

 Culture alone will be able to cause a deviation. 



" In order to understand this subject clearly, it will be 

 necessary to bear in mind, that any one of the alka- 

 line bases may be substituted for another, the action 

 of all being the same. Our conclusion is, therefore, 

 by no means endangered by the existence of a parti- 

 cular alkali in one plant, which may be absent in 

 others of the same species. If this inference be cor- 

 rect, the absent alkali or earth must be supplied by one 

 similar in its mode of action, or in other words, by an 

 equivalent of another base." — (pp. 149, 150.) 



This view is illustrated by statements of the 

 alkaline contents of the a.'jhes of different speci- 

 mens from different soils of the same plant ; in 

 which, ihougii the proportions ri\' the salts of pot- 

 ash, lime, and magnesia, varied considerably, yet 

 there was a remarkable equality in the total quan- 

 tities of oxygen (the acidifying principle) Ibund 

 in the ashes of each different specimen. 



" Firs and pines find a sufficient quantity of alkalies 

 in granitic and barren sandy soils, in which oaks will 

 not grow ; and wheat thrives in soils favorable for 

 the linden-tree, because the bases, which are neces- 

 sary to bring it to complete maturity, exist there in 

 sufficient quantity. The accuracy of these conclu- 

 sions, so highly important to agricidture and to the 

 cultivation of forests, can be proved by the most evi- 

 dent facts. 



" All kinds of grasses, the equisetacea, for example, 

 contain in the outer parts of their leaves and stalk a 

 large quantity of silicic acid and potash, in the form 

 of acid silicate of potash. The proportion of this salt 

 does not vary perceptibly in thesoU of corn-fields, be- 

 cause it IS again conveyed to them as manure in the 

 form of putrefying straw. But this is not the case in 

 i a meadow, and hence we never find a luxuriant crop 

 of grass on sandy and calcareous soils which contain 

 little potash, evidently because one of the constituents 



indispensable to the growth of the plants is wanting- 

 Soils formed from basalt, grauwacke, and porphyry 

 are, ccBteris paribus, the best for meadow land, on ac- 

 count of the quantity of potash which enters into 

 their composition. The potash abstracted by the 

 plants is restored during the annual irrigation. That 

 contained in the soil itself is inexhaustible in compa- 

 rison with the quantity removed by plants." — (pp. 

 158, 159.) 



" The most decisive proof of the use of strong manure 

 was obtained atBingen (a town on the Rhine,) where 

 the produce arid developement of vines were highly in- 

 creased by manuring them with such substances as 

 shavings of horn, &.c., but after some years the forma- 

 tion of the wood and leaves decreased to the great 

 loss of the possessor, to such a degree, that he has 

 long had cause to regret his departure from the usual 

 methods. By the manure employed by him, the vines 

 had been too much hastened in their growth ; in two 

 or three years they had exhausted the potash m the 

 formation of their fruit, leaves, and wood, so that none 

 remained for the future crops, his mjinure not having 

 contained any potash. 



" There are vineyards on the Rhine, the plants of 

 which are above a hundred years old, and all of these 

 have been cidtivated by manuring them with cow- 

 dung, a manure containing a large proportion of 

 potash, although very little nitrogen. All the potash, 

 in fact, which is contained in the food consumed by 

 a cow is again immediately discharged in its excre- 

 ments. 



'• The experience of a proprietor of land in the vici- 

 nity of Gottingen offers a most remarkable example 

 of the incapability of a soil to produce wheat or 

 grasses in general, when it fails in any one of the ma- 

 terials necessary to their growth. In order to obtain 

 potash, he planted his whole land with wormwood, the 

 ashes of which are well known to contain a large pro- 

 portion of the carbonate of that alkali. The conse- 

 quence was, that he rendered his land quite incapable 

 of bearing grain for many years, in consequence of 

 having entirely deprived the soil of its potash." — (p. 

 161.) 



"It is thought very remarkable, that those plants oi 

 the grass tribe, the seeds of which furnish food for 

 man, follow him like the domestic animals. But 

 saline plants seek the sea-shore, or saline springs, and 

 the chenopodium the dunghill from similar causes. 

 Saline plants require common salt, and the plants 

 which grow only on dunghills, need ammonia and 

 nitrates, and they are attracted whither these can be 

 found, just as the dung-fiy is to animal excrements. 

 So likewise none of our corn plants can bear perfect 

 seeds, that iy, seeds yielding flour, without a large sup- 

 ply of phosphate of magnesia and ammoida, substan- 

 ces which they require for their maturity. And hence, 

 these plants grow only in a soil where these three 

 constituents are found combined, and no soil is richer 

 in them, than those where men and animals dwell to- 

 gether; where the urine and excrements of these are 

 found corn plants appear, because their seeds cannot 

 attain maturity uidess supplied with the constituents 

 of those matters."— (pp. 162, 163.) 



Although it is now usually admitted that all 

 these salts, oxides, and earths left in ashes after 

 burning plants, are drawn by the roots from the 

 soil, still it has not been long since even scientific 

 investigators maintained that they were produced 

 by the growth of plants, and were to be found 

 in their structure even when not present in the 

 soil. Schrader, a German chemist, says Profes- 

 sor Daubeny, " was honored with a prize from 

 the Berlin Academy, for having, as was thought, 

 established this position." 



How then does it happen that so many of these 



