THE FARMER'S MAGAZINE. 



387 



5. Pigeons and Poultry Dung. 

 The dung of pigeons is of a very powerful nature, 

 but very hot and stimulating', and abounds with the 

 volatile alkaline principle. Is contains uric acid, and 

 gives by distillation carbonate of ammonia, yields 

 soluble matter in water, and is very liable to ferment. 

 It also possesses an acid of a peculiar nature, which 

 increases when the matter is diluted witli water ; but 

 gradually gives place to ammonia, which is at last 

 abundantly exhaled. It affords carbonate of ammonia, 

 and leaves as a residuum carbonate of lime and saline 

 matter, chiefly common salt. Tlic dung of poultry 

 contains silica, carbonate and phosphate of lime, and, 

 along with the dung of pigeons, is mixed with earths 

 and ashes, and applied as top-dressing in the usual 

 method and quantity. The preparation of the com- 

 post must be minutely performed, and very intimately 

 blended, in order to prevent the fiery and corrosive 

 fermentation of tlie excrements, and to destroy the 

 clinging together of the poultry dung. The quantity is 

 small of these excrements that come into the hands of 

 the farmer — the readiest application will be to spread 

 the materials evenly on the top of a dung heap, just 

 before being turned over, which will mix the substances 

 and extend the ber.efi's equally. But when a quantity 

 is found that justifies the preparation of an cartliy 

 compost, a top-dressing of great efficacy may be ob- 

 tained. The excrements of winged animals are to be 

 used fresh in the mixture, as the fiery nature wastes 

 the substance and corrodes the residue. 



Section III.— SALINE SUBSTANCES. 

 1. Salt. 

 Common salt is the muriate of soda, or chloride of 

 sodium, and contains 



Sodium 39-66 



Chlorine 00-34 



100-00 



It is found in mineral deposits as a rock in sea 

 water, and in many saline springs. Earthy impurities 

 are found in salt, as salts of magnesia and lime : it is 

 a promoter of vegetation in certain cases — an excess of 

 it destroys organic life, and the effects hitherto are not 

 large enough to encourage the use of the article. The 

 deliquescent nature of salt very quickly dissipates the 

 substances, and it is preferred to mix it with earths, 

 and to apply the compost on grass lands at twenty 

 loads to an acre. The quantity of twenty bushels of 

 pure salt has been fixed as a proper quantity for top- 

 dressing an acre of pasture in spring or in autumn. 

 Saline manures require to be used on a moist surface 

 of ground, and with warm weather. 



2. Nitrate op Soda 



is the fossil alkali in combination with the nitric acid, 



and contains^ 



Acid 62.1 02.5. 62.81 



Base 37.9 37.5 37.19 



100.0 100.0 100.00 

 It was formerly called cubic nitre, and occasionally 

 mentioned by the chemical writers of the last century. 

 It is more bitter than nitre, has a cool, sharp taste, 

 crystals very transparent, soluble in three parts of 

 water, and in less than its weight of boiling-water; ex- 

 posed to the air it attracts moisture, and in the fire 

 resembles nitre, except in not melting so easily. Specific 

 gravity, 2.0904. It is found in the East Indies and in 

 Peru, whence the chief supply is derived. It is prin- 

 cipally used in preparing nitric acid, the deliquescent 

 quality rendering it unfit for use in the composition of 



gunpowder. The stratum is found below the surface 

 on the edges of a plain of vast extent, and in a nearly 

 pure state. It is also an artificial salt, and may be 

 formed by a combination of its constituents in a direct 

 soluuon, or by mixing the nitrate of lime and the sul- 

 phate of soda together, filtering the solution, and eva- 

 porating. 



The most recent character of nitrate of soda finds 

 the substance to bo very deliquescent in moist air, at- 

 tracts much moisture, and dissolves in twice its own 

 weight of water. It contains — 



Soda 36.7 



Nitric acid 63.3 



100.0 

 It has proved the most effectual and generally use- 

 ful of all saline manures as a top-dressing on young 

 crops of grains and roots. One bushel mixed with two 

 bushelsof common salt is the most approved mode of 

 application. Tlie price is about 16s. per cwt., and ia 

 sown by hand in the spring after being pounded into 

 dust. The effect on grass lands has increased the pro- 

 duce by one-third and one-fourth, and well repays the 

 expense ; and best used after gentle warm rains, fol- 

 lowed by heat, 



3. Nitre, 



or saltpetre, is the nitrate of potass, a native mineral 

 that occurs in all the four quarters of the globe. The 

 average constituents are — 



Acid 44.0 and 31 



Potash 51 .8 and 01 



Water . . , 4.2 and 8 



100.0 100 

 The use of nitre is very large in the composition of 

 gunpowder, and also in medicine, and many of the 

 arts. Specific gravity, 1.920 and 1.9309. The ancients 

 confounded nitre with soda or natron, and leaves us in 

 doubt whether or not they knew nitre ; but it was 

 known to Bacon, in the thirteenth century. Nitric 

 acid is one of the most powerful acids that is known, 

 and constituted of nitrogen and oxygen in a peculiar 

 proportion to each other — about 70.5 of oxygen and 

 29.5 of nitrogen. 



Pounded nitre lias been sown by hand as a top- 

 dressing on various crops, and with very fair success. 

 On grass lands nitre increased th.e quantity by one- 

 third, and the herbage was much earlier. The effects 

 are hardly equal to nitrate of soda from equal quanti- 

 ties of the two articles; and nitre being much dearer, 

 the superior merits belong to nitrate of soda. 

 4. Sulphate of Potash. 



Sulphate of potash contains 

 Neutral Sulphate. 



Potash 54-08 



Sulphuric acid 45-92 



Acid, or Bisulphate. 



Potash. 34-65 



Sulphuric acid. . . . 58 74 

 Water 6-61 



Total 100-00 



Total 10000 



Sulphate of potash is high in price, and few trials 

 have been made with it. The bisulphate is lower in 

 price, and a by-product of several chemical works, and 

 is a strong fertilizer, though no precise experiments 

 have been recorded. 



5. Sulphate of Soda. 



Sulphate of soda is formed of soda and sulphuric acid 

 in nearly equal parts. It acts well as top-dressing on 

 grain crops, and on roots, and on grass lands where the 

 return paid well for the expense. 



Sulphur is supplied to growing plants in order to 

 produce a healthy condition. Plants contain sulphur 

 in diflferent quantities, and will be unequally affected 



