OF MANURE. 



67 



application of the heat employed in drying 

 the manure. The addition of a cheap mine- 

 ral acid to the night-soil,, before admixture 

 with these ingredients, would materially 

 improve both of the above processes. 



It would no doubt be highly advantageous 

 in the preparation of manures, to prepare 

 them so that they contained all the ingredi- 

 ents necessary for the supply of the plants 

 to which they are applied. But these will 

 of course vary according to the nature of 

 the soils and plants for which they are in- 

 tended. Thus bones, soap-boilers' waste, 

 nitrate of soda, and ashes of wood, will 

 often be found to form advantageous addi- 

 tions. Sulphate of magnesia (Epsom salts) 

 would, in most cases, form an invaluable 

 ingredient in prepared night-soil. (See Sup- 

 plementary Chapter on Soils.) The pro- 

 ducts of the decomposition proceeding from 

 the action of this salt upon night-soil are, 

 sulphate of ammonia, phosphate of mag- 

 nesia, and the double phosphate of magnesia 

 and ammonia. Now all these salts exert a 

 very favourable influence upon vegetation, 

 and the phosphate of magnesia is, in many 

 cases, perfectly indispensable to the growth 

 and developement of certain plants. This 

 suggestion is well worthy of the attention 

 of the farmer. 



Perhaps the best and most practical me- 

 thod of fixing the ammoniacal salts of urine 

 and night-soil, is to mix them with the 

 ashes of peat or coal. When the latter are 

 employed, care must be taken to select such 

 as are of a porous, earthy consistence. The 

 ashes both of peat and coal contair in gene- 

 ral magnesia ; hence their value as an in- 

 gredient of prepared night-soil. When 

 magnesia is not present, it will be necessary 

 to add some magnesian limestone or Epsom 

 salts. The night-soil should be mixed tho- 

 roughly with the ashes, and exposed to the 

 air to dry. The disagreeable smell is thus 

 quickly removed, and a pulverulent manure 

 obtained, which can be applied to the fields 

 with facility. 



Animal charcoal, which has served for 

 the discoloration of sugar, possesses the pro- 

 perty of removing the offensive smell of 

 night-soil, and is of itself an admirable ma- 

 nure. In cases where it can be procured 

 with facility, it will be found to add to the 

 efficacy of the latter. 



GUANO. 



The sterile soils of the South American 

 coas\ are manured with a substance called 

 guano, consisting of urate of ammonia and 

 other ammoniacal salts, by the use of which 

 a luxuriant vegetation and the richest crops 

 are obtained. Guano has lately been im- 

 ported in considerable quantity into Liver- 

 pool and several other English ports, and is 

 now experimentally employed as a manure 

 by English agriculturists. A consideration 

 of its composition and mode of action can- 

 not, therefore, fail to be acceptable. 



I Much speculation has arisen as to the 

 I true origin of guano,* but the most certain 

 proof is now afforded, that it has been. pro- 

 duced by the accumulation of the excre- 

 ments of innumerable sea-fowl which inhabit 

 the islands upon which it is found. Meyen, 

 the latest writer upon this subject, com- 

 pletely coincides with this opinion ; for he 

 saysf " Their number is Legion ; they 

 completely cloud the sun, when they rise 

 from their resting-place in the morning in 

 flocks of miles in length." Yet, notwith- 

 standing their great number, thousands of 

 years must have elapsed, before the excre- 

 ments could have accumulated to such a 

 thickness as they possess at present. Guano 

 has been used by the Peruvians as a manure 

 since the twelfth century ; and its value was 

 considered so inestimable, that the govern- 

 ment of the Incas issued a decree, by which 

 capital punishment was inflicted upon any 

 person found destroying the fowl on the 

 Guano islands. Overseers were also ap- 

 pointed over each province, for the purpose 

 of insuring them further protection. Under 

 this state of things, the accumulation of the 

 excrements may have well taken place. All 

 these regulations are, however, now aban- 

 doned.J Rivero states that the annual con- 

 sumption of guano for the purposes of agri- 

 culture amounts to 40,000 fanegas. The 

 increase of crops obtained by the use of 

 guano is very remarkable. According to 

 the same authority, the crop of potatoes is 

 increased 45 times by means of it, and that 

 of maize 35 times. The manner of apply- 

 ing the manure is singular. Thus in Arica, 

 where so much pepper ( Capsicum baccatum) 

 is cultivated, each plant is manured three 

 times : first upon the appearance of the roots, 

 second upon that of the leaves, and lastly 

 upon the formation of the fruit. (Humboldt.) 

 From this it will be observed, that the Pe- 

 ruvians follow the plan of the Chinese, in 

 manuring the plant rather than the soil. 

 The composition of guano points out how 

 admirably it is fitted for a manure ; for not 

 only does it contain ammoniacal salts in 

 abundance, but also those inorganic consti- 

 tuents which are indispensable for the de- 

 velopement of plants. 



The most recent analysis is that of Volc- 

 kel, who found it to consist of 



Urate of Ammonia . . . . 9.0 



Oxalate of Ammonia . . . 10.6 



Oxalate of Lime . . 7.0 



Phosphate of Ammonia . . . 6.0 



Phosphate of Magnesia and Ammonia 2.6 



Sulphate of Potash ... 5.5 



Sulphate of Soda .... 3.8 



Sal-ammoniac . , . 4.2 



Phosphate of Lime 14.3 



Clay and Sand : . . 4.7 



* Much of the information regarding Guano 

 here given is extracted from a paper in Liebig'g 

 Annalen, xxxvii. 3, 291. 



t Reise urn die Erde, B. i. S. 434. 



t Garcilaso, Ilistoria de los Yncat, vol. i 

 p. 134. 



