840 



THE FARMERS' REGISTER. 



performed in exact accordance with the views of 

 their author— I have concluded to direct your 

 attention to what I conceive to be an im[)ortani 

 error in Squarey's Treaiise. He says, 



" Another compost heap, which would answer 

 admirably for any purpose almost lor which a ma- 

 nure can be required, that is, eiiher as a Kiimulant 

 for turnips, as a pabulum for wheat, or wliiie crops 

 — or, again, as a top-dressing for eiiher of the 

 above, or lor grass — may be readily formed by 

 mixing long stable litter, in which decay has al- 

 ready commenced, with the burnt ashes of vege- 

 tables or wood, in somewhat indefinite portions; 

 taking care, however, that the litter should pre- 

 dominate, and then pouring over the heap daily a 

 portion of the putrid urine, and stirring the mass 

 well up together. 



" In this heap the ammonia of the urine would 

 be decomposed; but the nitrogen, the vivifying 

 principle of the ammonia, would unite with the 

 alkaline matter, the soda or potasii of the burnt 

 vegetable ashes, to form nitrate of potash or soda : 

 the hydrogen, the other constituent of ammonia, 

 being given off." 



In such a heap, the carbonate of ammonia, re- 

 sulting chiefly from the decomposition of the urea 

 of the putrefying urine, would be decomposed and 

 lost. The nitrogen of the ammonia would, by 

 combining with oxygen of the air, form nitric 

 acid, which, by uniting with potaesa, lime, alumi- 

 na, &c., would give rise to various soluble nitrates. 

 The manure so formed would be very valuable ; 

 but its action as a fertilizer would depend, not on 

 the nitrHiee, if Liebig's opinions are correct, but 

 on the phosphates and other salts, which, in such 

 a heap, would escape decomposition, and which 

 are very valuable ingredients of soils. Indeed, 

 Squarey admits that the ammonia of the urine 

 would be decomposed; and any one, who has 

 attentively read Liebig's work, must be aware, 

 that he ascribes much of the eflicacy of urine as 

 a manure, to its ammoniacal salts, and attaches 

 no importance to nitrates, even in the culture of 

 plants, part of which contain nitrates. 



"Ammonia, (says Liebig — Webster's edi- 

 tion. 1841, p. 138,) by its translbrmation, fur- 

 nishes nitric acid to the tobacco plant, sun-flower, 

 chenopodium, and borago ofRcinalis, when they 

 grow in a soil completely free from nitre, (nitrate 

 of potash.) Nitrates are necessary constiiuenis 

 of these plants, which thrive only where ammonia 

 IB present in large quantity, and where they are 

 also subject to the mfluence of the direct rays of 

 the sun, an influence necessary to effect the dis- 

 engagement, within their stems and leaves, o( 

 the oxygen, which shall unite with the nitrogen 

 of the ammonia to form n'tric acid." 



Hence it appears, that Liebig believes the con- 

 version of ammonia into nitric acid, to be in such 

 plants as tobacco an essential process of assimila- 

 tion. If this be true, (and Squarey says "the 

 powerful influence of urine must consist in its 

 ammoniacal salts,") the process recommended 

 by him must deprive the urine of its most abun- 

 dant and most valuable ingredient. And if the 

 nitrates, found in plants, are products ot processes 

 of assimilation, such salts, presented ready formed 

 to their roots, can have no good efl^ect, and may 

 have a bad one. At all events, it has been ascer- 

 tained that such plants grow well in soils which 

 do not contain niire. 



1 am aware that Squarey's, or a similar mode 

 ol" employing urine, is recommended by some 

 scientific men, and that it is practised successfully 

 "in the vicinity of some of the large cities of the 

 United States." This, however, does not prove 

 that it is the best mode of employing urine. Sci- 

 entific men have devoted very little time to the 

 invesMsation of the subject ; for, as Liebig 

 remarks, " since the time of the immortal author 

 of the ' Agricultural Chemistry,' no chemist has 

 occupied liimsell in studying the applications of 

 chemical principles to the growth of vegetables." 

 And the practice of our most intelligent agricultu- 

 rists is often erroneous ; and the apparent success 

 of that which I am now opposing, proves only, 

 what every chemtst, acquainted with the nature 

 and number of the salts of urine, would expect, 

 that it is a valuable manure, when deprived of 

 that ingredient, which is most lertilizing, and of 

 which it contains the largest quantity. 



Liebig describes several modes of preparing 

 manure from human and animal excrements, both 

 fluid and solid, which he characterizes as " the 

 most injudicious which could be conceived." 

 And the principle of Squarey's method is ex- 

 pressly condemned. 



" In other manufactories of manure, the ex- 

 crements while soft are mixed with the ashes of 

 wood, or with earth, both of which substances 

 contain a large amount ol caustic lime, by means 

 of which a complete expression ol" their ammonia 

 is effected, and they are completely deprived of 

 smell. But such a residue can act only by the 

 phosphates which it still contains, (or all the am- 

 moniacal salts have been decomposed, and their 

 ammonia expelled." ( Webster''8 edition, 1841, 

 p. '243.) 



It would, therefore, he much better to employ 

 wood ashes, lime, and other alkaline substances, 

 in the way recommended by Liebig, which is to 

 scatter them over the surface of the soil, exactly 

 as the planter sows wheat or oats; (or though 

 these alkaline substances are valuable manures, 

 they all have a greater or less tendency to decom- 

 pose ammoniacal salts, and to expel their volatile 

 alkali, ammonia. Il is however an advantage, 

 where ilie soil contains a proper mixture of alka- 

 line substances ; Ibr the ammoniacal salts of the 

 manures, formed (i-om animal excrements, condng 

 gradually into contact with them, are slowly de- 

 composed during the growth of the crop, and the 

 ammonia, while in a nascent stale, is presenled to 

 the rootlets of the plants, in the best potisible (brm 

 for absorption. This is the mode that has, (or 

 years, been adofiled with so much success in 

 Scotland ; and ihe practice of that nation is in ex- 

 act accordance wi'h the views of Liebig. 



There is not, it appears to me, any way in 

 which ashes, linre, or other alkaline substances, 

 can be economically applied to compost heaps 

 formed of animal excrements. Gypsum, coppe- 

 ras, or some other similar salt, which readily 

 yields its acid to ammonia, should be spread over 

 the heap and mixed with it ; or sulphuric acid, 

 very much diluted with water, should be mixed 

 witli the liquid excrements, before they are poured 

 on it ; or it should be mixed with burnt clay, 

 ashes of coal, pulverized charcoal, or some other 

 substance which has a powerful aflinity for am- 

 monia ; or it should contain so much litter as (o 

 absorb most of the putrid urine, and thereby pre- 



