ANALYSIS. 



ANALYSIS. 



which will result by decomposition or decay 

 " that which exists in possibility, not in act." 

 Now the former is almost invariably soluble 

 with ease in water, and is thus readily and 

 immediately available to plants ; while the 

 latter must first become "actual" by decay, 

 before it can assist in supporting vegetation. 



In Peruvian guano, we have about half of 

 the ammonia ready formed, and easily soluble 

 in water; the remainder exists in the form of 

 uric acid, which yields ammonia by decay in 

 the soil, but may require weeks or months to 

 complete the change. In leather shavings or 

 woollen rags the ammonia is all potential ; and 

 as these bodies decay slowly, they are of less 

 value than guano as sources of ammonia. Oil- 

 cake (linseed and cotton seed) contains much 

 potential ammonia, and in a form that very 

 speedily yields actual ammonia. 



We do not know with what precise results 

 the process of the decay of ammonia-yielding 

 bodies is accomplished in the soil. Out of the 

 soil, such bodies do not give quite all their 

 nitrogen in the form of ammonia : a portion 

 escapes in the uncombined state, and thus 

 becomes unavailable. 



Phosphoric acid may occur in two different 

 states of solubility ; one readily soluble, the 

 other slowly and slightly soluble in water. 

 The former we specify as soluble, the latter as 

 insoluble in phosphoric acid. In Peruvian 

 guano we find 3.5 per cent, of soluble phos- 

 phoric acid, existing there as phosphates of 

 ammonia and potash. The remaining 10 to 

 12 per cent, is insoluble, being combined with 

 lime and magnesia. In most other manures, 

 genuine superphosphates excepted, the phos- 

 phoric acid is insoluble. 



Among those phosphates which are here 

 ranked as insoluble, there exist great differ- 

 ences in their availability, resulting from their 

 mechanical condition. The ashes of bones, 

 and the porous rock-guano, when finely ground, 

 exert immediate etfect on crops, while the 

 dense, glassy, or crystallized phosphorite of 

 Hurdstown, N. J., and the fossil bones (so- 

 called coprolite of England), are almost or 

 quite inert unless subjected to treatment with 

 oil of vitriol. 



The reasonable price of phosphoric acid, ammo- 

 nia, and potash. 



Insoluble phosphoric acid. There are several 

 substances now in market, which, as fertil- 

 izers, are valuable exclusively on account of 

 their content of phosphoric acid; which, 

 moreover, are at present the cheapest sources 

 of this substance that possess the degree of 

 fineness proper to an active fertilizer. These 

 substances are the phosphatic guanos, (from 

 the Gulf of Mexico, &c.,) and the refuse bone- 

 black of the sugar refineries. From them we 

 can easily calculate the present lowest com- 

 mercial value of phosphoric acid. If we di- 

 vide the price per ton of the guano, $35, by 

 the number of pounds of phosphoric acid in a 

 ton, which, at 40 per cent., amounts to 800 

 pounds, then we have the price of one pound 

 as nearly 4J cents. 



Refuse bone-black may be had for $30 per 

 ton ; it usually contains 32 per cent, of phos- 

 phoric acid. The same division as above 

 94 



gives us 4f cents as the cost of phosphoric 

 acid per pound. 



In this report I shall adopt the average of 

 these figures, viz. 4 cents, as the reasonable 

 price of insoluble phosphoric acid. 



Phosphoric acid is much cheaper in crushed 

 bones; but this material is not in a suitable 

 state of division to serve as the basis of a fair 

 estimate. 



Soluble phosphoric acid. This is nearly al- 

 ways the result of a manufacturing process. 

 Professor Way, chemist to the Royal Agricul- 

 tural Society of England, estimates its worth 

 at 10 cents per pound. Dr. Voelker, of the 

 Royal Agricultural College of England, and Dr. 

 Stoeckhardt, the distinguished Saxon Agricul- 

 tural Chemist, reckon it at 12 J cents per pound. 

 They have deduced these prices from that of 

 the best commercial superphosphates. In 

 this report the price will also be assumed at 

 12 cents. This, I believe, is considerably 

 more than it is really worth, but is probably 

 the lowest rate at which it can now be pur- 

 chased. 



Actual ammonia. One of the cheapest 

 sources of this body is Peruvian guano. Al- 

 though it contains several per cent, of poten- 

 tial ammonia, yet the latter is so readily con- 

 verted into actual ammonia, that the whole 

 effect of the manure is produced in one sea- 

 son, and therefore we may justly consider the 

 whole as of equal value with actual ammonia. 



Good Peruvian guano contains: 



2 per cent., or 40 pounds per ton, of potash; 



3 " " " 60 " " " soluble 

 phosphoric acid; 



12 per cent., or 240 pounds per ton, of insol- 

 uble phosphoric acid ; and yields 



16 per cent., or 320 pounds per ton, of am- 

 monia. 



If we add together the values of the potash 

 and of the phosphoric acid, soluble and insol- 

 uble, and subtract the same from the price of 

 guario, we shall arrive at the worth of the am- 

 monia namely, $45.10 per 320 Ibs., or about 

 14 cts. per pound. 



This price, 14 cents per pound, will be em- 

 ployed in these estimates. 



Potential ammonia, (flesh or other animal 

 matter.) The value of this varies so greatly, 

 being, for example, as uric acid in guano, not 

 inferior to actual ammonia, while in woollen 

 rugs it is not worth more than one-half as 

 much, that we can fix no uniform price, but 

 must decide what it shall be, in each special 

 case, separately. 



Potash. The value of potash is difficult to 

 estimate, because it may vary exceedingly ac- 

 cording to circumstances. Wood ashes are its 

 chief sources ; these are poor or rich in pot- 

 ash according to the kind of tree that yields 

 them, and the soil on which it has grown. It 

 may vary from five to twenty per cent. 

 Stoeckhardt, who estimates the value of am- 

 monia at twenty cents, makes potash worth 

 four cents per pound. The price of potashes 

 cannot serve as a guide, for they are never 

 used for agricultural purposes. Four cents is 

 certainly high enough for this country if it is 

 correct for Germany. 



