ANALYSIS. 



Potash may le usually neglected. 



Most concentrated manures contain very 

 little or no potash. In guano it rarely ex- 

 ceeds three per cent. Superphosphate of lime 

 can contain none of consequence. Potash 

 cannot be economically added to manufactured 

 manures, because nearly pure potash, or even 

 the raw material from which it is extracted, 

 viz. wood ashes, has a higher commercial 

 value for technical than for agricultural pur- 

 poses. Besides, potash is not generally de- 

 ficient in soils, and therefore farmers do not 

 wish to pay for it us an ingredient of costly 

 manures. It is only when a manure is pro- 

 fessedly sold a.s containing much potash, that 

 this ingredient deserves to be taken account 

 of in its valuation. 



Computint/ the money-value of concentrated ma- 

 nures. 



In what immediately precedes, is contained 

 the data for calculating approximatively the 

 price that can be afforded for a high-priced 

 manure, it' we have before us the results of a 

 reliable analysis. The actual calculation is 

 very easy, and has been illustrated already in 

 deducing the value of ammonia from Peruvian 

 guano. We give here a resume of the prices 

 adopted in this report, viz.: 



Po'ta-h, per pound 4 cts. 



Insoluble phosphoric acid, per pound, 4J " 

 Soluble " " ' 12J " 



Actual, and some forms of potential 



ammonia 14 " 



As a further example of the calculation, 

 here may follow the details of the valuation 

 of a superphosphate of lime. Analysis gave 

 the following percentages: 



Actual ammonia 2 39, say 2.4 



Potential " 1.0>, 1.0 



Soluble phosphoric acid ... 2.56, 2.6 

 Insoluble " " ...22.98, " 23.0 



Multiplying the percentage of each ingre- 

 dient by its estimated price, and adding to- 

 gether the products thus obtained, j: | 

 value of one hundred pounds; this taken 

 twenty times, gives us the worth- of a ton of 

 two thousand pounds, namely 36.80 per ton. 



In the case before us, the quantity of po- 

 tential ammonia is so small that we may 

 reckon it with the actual ammonia without 

 materially influencing the result. 



Lime. Its agency in liberating potash, 

 soda, ,S:c. Burned lime, while in its caustic 

 Btate (freshly slaked or hydrate), exerts great 

 activity in decomposing the insoluble organic 

 as well as inorganic constituents in any soil. 

 This is demonstrated by the chemist who, 

 wanting to separate potash and soda from a 

 portion of earth, heats this red-hot, in a cru- 

 cible, with a portion of lime. After cooling, 

 all the potash and soda contained in the por- 

 tion of earth can readily be washed out by 

 simply passing water through it. 



Carbonate of lime added to a soil will also 

 effect the liberation of potash, soda, and am- 

 monia present, but it will require considerable 

 time. Caustic lime produces these effects at 

 once. Hence the great advantage of applying 

 lime to land in a caustic state when a coin- 



ANALYSIS. 



paratively small portion will do the work for 

 which a very large quantity of effete carbonate 

 of lime would be required. As a matter of 

 economy, this knowledge is of the greatest 

 consequence. 



Another important agency of lime is in de- 

 composing the insoluble silicates, phosphates, 

 etc., and rendering these soluble so as to be 

 readily absorbed by the roots of growing 

 plants. 



Oyster-shells. 100 parts, according to Kane's 

 analysis, contain 



Carbonate of lime 98.5 



Phosphate of lime 1.0 



Animal membrane 0.5 



100.0 



From this it would appear that 100 bushels 

 of oyster-shells would contain 1 bushel (say 

 75 or 80 Ibs.) of phosphate of lime in ad- 

 dition to 98 bushels of carbonate of lime. 



Gas Lime, or refuse lime from gas-works. 

 This has been analyzed and found to vary in 

 its constituents in the various places, accord- 

 ing to the composition of the lime employed 

 and other causes. The following analysis, 

 reported by Professor Johnson, of England, 

 shows results obtained from this refuse from 

 the gas-works of Edinburgh and London. 



EJinb. London. Edinb. London. 

 Water and coal tar 12.91 9.59 12.91 9.59 

 Carbonate of lime 69.04 58.88 67.39 56.41 

 Hydrate of lime, 



(caustic,) 2.49 5.92 



Sulphate of lime, 



(gypsum,) 7.33 2.77 16.45 29.32 



Sulphite and hypo- 

 sulphite of lime 2.28 14.89 

 Sulphuret of cal- 

 cium 0.20 0.36 



Sulphur 1.10 0.92 



Prussian blue 2.70 1.80 .2.70 1.80 



Alumina and oxide 



of iron 3.40 3.40 



Insoluble matter, 



(sand, &c.) 0.64 1.29 0.64 1.29 



98.69 99.82 100.00 101.81 

 From the above analysis it appears that the 

 two most noxious constituents sulphite and 

 hyposulphite of lime constitute 14 per cent, 

 and more in the sample from the London Gas 

 Works, whilst it only makes about 2 per cent, 

 of the sample from Edinburgh. As these 

 forms of lime are pernicious to vegetation, un- 

 favourable results might be reported from the 

 gas lime in which they most abound, which 

 would be contradicted by those who used the 

 lime from places where these constituents were 

 present in minuto proportions. Hence the 

 great importance of determining the qualities 

 or constituents of gas lime before making use 

 of it. In Philadelphia the gas lime is made 

 from oyster-shells. In other cities, stone lime 

 is employed in the gas-works. Any danger 

 from the noxious ingredients often contained 

 in gas lime may be removed by composting 

 with muck, peat, or barn-yard manure, and 

 suffering to remain long enough to admit of 

 the noxious substances being converted into 



95 



