194 Solubility of Phosphatic Materials. 
Composition of a sample of inferior Bone-flour {^Commercial precipiLated 
Uone-phosphatea). 
Moisture (loss at 212° F.) 16-87 
Organic matter and combined water ,. .. 5"01 
Tribasic phosphate of lime 36-28 
Carbonate of lime 4-65 
Chloride of calcium 31-72 
Insoluble siliceous matter (sand) 5-47 
100-00 
Chloride of calcium is a very deliquescent salt, which is 
injurious to vegetation, and therefore ought not to occur in so 
large a proportion as it did in this sample. 
An excellent artificial manure for root-crops may be obtained by 
mixing together 3 parts of prepared precipitated bone-phosphate 
with 3 parts of Peruvian guano. Applied at the rate of 4 cwts. 
per acre, the mixture will be found especially useful for root- 
crops intended to be grown on light land. 
Equal parts of precipitated bone phosphate (of a good sample), 
Peruvian guano and common salt, and applied at the rate of 
8 to 9 cwts. to the acre form a capital dressing for permanent 
pasture. 
Summary. 
The chief points of interest embodied in the preceding pages 
may be briefly summarised as follows : — 
1. Pure and dried phosphate of lime is sparingly soluble in 
water. 
2. In a moist state and the voluminous condition in which it is 
obtained by precipitation from its solution, it is about four times 
as soluble in water as it is after it has been dried and heated. 
3. Ammoniacal salts added to water materially increase the 
solubility of pure phosphate of lime, and of the phosphates in 
bone-ash, coprolites, and other phosphatic minerals. 
4. Nitrate of soda and common salt neither increase nor 
diminish the solubility of phosphates in water. 
5. Bone-ash is not sufficiently soluble in water to be used with 
advantage by itself or mixed with other fertilising matters as a 
manure. 
6. The earthy phosphates in Peruvian and phosphatic guanos, 
still containing a good deal of organic matter or salts of am- 
monia, are sufficiently soluble in water to be readily appropriated 
by plants. 
7. The phosphates contained in coprolites, apatite, Sombrero 
rock, Spanish phosphate, and other phosphatic minerals, especi- 
