426 



THE FARMER'S MAGAZINE. 



good crop of clover, we at the same time enrich the 

 land with nitrogenous matters, and provide for the 

 succeeding white crop that kind of food for which 

 it appears to be specially grateful. The fact that 

 a good crop of wheat may be confidently antici- 

 pated after a good clover-crop is generally admitted ; 

 the power of the clover to accumulate nitrogenous 

 matter in the soil, which explains this result, may 

 not be as fully recognised. Moreoveg, whilst few 

 soils contain more than traces of phosphoric acid, 

 nearly every kind of agricultural produce contains 

 this acid in very large and often preponderatmg 

 proportions ; its presence being further required to 

 furnish the phosphorus which largely enters into 

 the composition of albumen, gluten, legumine, and 

 indeed all albuminous compounds. How large then 

 is the demand for those constituents which even 

 the best soils supply but in scanty proportions ! 

 We can thus understand why their direct supply 

 in an available condition is of more vital importance 

 to our cultivated crops than that of any other fer- 

 tilizing substance. 



When superphosphate of lime was first made in 

 England, fresh or raw bones were alone employed. 

 Then came the Suffolk cropolites, whose use was 

 originally recommended by the late most excellent 

 and lamented Professor Henslow; and in 1839, I 

 had suggested the employment in a finely powdered 

 state of the apatite, or phosphorite as manures, 

 since these minerals are almost entirely composed 

 of phosphate of lime. 



More lately phosphate of lime in these and other 

 forms has been pressed into the service of the 

 manure makers, with the greatest succes, Most 

 of these have been analyzed by Professor Voelcker, 

 viz. : 



Norwegian apatite. 



Spanish phosphorite. 



Cambridgeshire coprolites. 



Suffolk c(5prolites. 



American phosphate (Maracaibo guano). 



Sombrero or crust guano. 



Kooria Mooria guano. 



South American bone ash. 



Animal black, or bone charcoal. 



But the Professor did not confine himself to 

 these phosphatic matters : he extended his very 

 valuable researches to the composition of the re- 

 cent bone, and his results are the most complete and 

 useful that have hitherto been obtained. I cannot 

 bring myself to abridge his report of these im- 

 portant inquiries. He remarks {ibid p. 379) : 



"Bones are used for agricultural purposes in the 

 following states : 

 Bone-dust. 

 Boiled bones. 

 Bone shavings. 



" BONE-DUST. 



"Before crushing, raw or butchers' bones are now 

 generally boiled out in an open cauldron, and by 

 this means deprived, in a great ? measure, of their 

 fat. As an article of commerce, fat is the most 

 valuable constituent of bones. As a manuring 

 agent it has no value whatever ; or perhaps, more 

 strictly speaking, its presence is undesirable, inas- 

 much as it retards the decomposition and solution 

 of the bones. Far from being injurious, the re- 



moval of fat from the bones decidedly improves 

 their agricultural value. The following is the 

 average composition of a number of samples of 

 bone-dust analyzed by me : 



Moisture ... ]2'06 



^Organic matter 29" 12 



Phosphates of lime and magnesia 



(bone-earth),. .. .. .. 49'5i 



Carbonate of lime (determined by dif- 

 ference) ,. .. .. .. 6'99 



Alkaline salts and magnesia (chiefly 



common salt) .. .. .. 1*91 



Sand -38 



100-00 



^Containing nitrogen . . . . 3"69 

 Equal to ammonia . . . . 4*49 



" In the next table is given the composition of 

 No. 1. Sound foreign bones. 

 „ 2. Decayed foreign bones. 

 5, 3. Decayed and sound foreign bones 



mixed. 

 ,, 4. London bones. 



Moisture 



♦Organic matter . . 

 Phosphate of lime and 

 magnesia(bone-earth) 

 Carbonate of lime . . 

 Alkaline salts 

 Sand 



No. 1. 



12-02 



28-71 



49'28 

 4-37 

 4-55 

 1-07 



*Containing nitrogen 

 Equal to ammonia . . 



No. 

 12- 



27. 



2.iNo. 3. 

 15' 12-13 

 27| 27-80 



No. 4. 

 12-31 

 30-73 



52-99 52-70 49-72 

 2- 



-35 

 -59 

 •65! 



4-17 



2-84 

 -36 



4-25 



2-78 



•21 



100 00 100 00 10000 10000 

 3-44 3'31 3-43 3-73 

 4-17 4 02 4-16 4-52 



" In decayed bones the proportion of organic 

 matter is not quite so great as in sound bones, 

 and the phosphates are rather higher. But the 

 differences are not sufficiently striking to require 

 any comment. In the preceding analyses, the 

 lime which is left in solution after the phosphates 

 have been removed has likewise been determined 

 quantitatively. Calculated as carbonate of lime, 

 it amounts in the four analyses to 8-60, 8-7lj 7'50, 

 7-78, respectively. 



"boiled bones. 



"The bones from which glue-makers have ex- 

 tracted a certain portion of gelatine and nearly all 

 the fat are known in commerce under the name of 

 boiled bones. It must not be supposed, however, 

 that boiled bones do not contain any organic 

 matter, nor furnish on decomposition any ammonia. 

 The following two analyses show the contrary : 



Composition of Two Samples of Boiled Bones. 



