192 
Soluhility of Phosphatic Blaterials. 
taincd by me by digesting various forms of bone-dust with 
salt solutions have no special interest, I content myself by 
mentioning only two or three which give as good a proof in su])- 
port of the opinion just expressed as that afforded by the whole 
series. 
500 grs. of fine hard bone-dust and 200 grs. of salt were 
mixed with 1 decigallon of water, and the phosphate dissolved 
bv the saline liquid afterwards determined. 
Under the same circumstances as those in which pure water 
dissolved 2"80 and 2'10 grains of bone-phosphate per gallon, salt 
solutions took up 2"10 and 2"40 grains of bone-phosphates re- 
spectively, or almost precisely the same quantities as pure water. 
I may mention in passing that lately a peculiar description of 
bone-dust has been seen occasionally in the manure market. It 
is imported from Belgium, and sold as prepared Belgian bones. 
It is very brittle, generally rather damp, emits a strong ammo- 
niacal smell similar to that of rotten cheese, and appears to 
be a refuse obtained in the manufactory of gelatine or some such 
substance. Prepared Belgian bones, like English glue-makers' 
boiled or refuse bones, when dry are readily ground into a fine 
powder, which though not so valuable as fine ordinary bone-dust 
lor manure, may nevertheless be used with advantage both for 
root crops and for pastures. 
Three samples analysed by me a short time ago had the 
following composition : — 
Composition of Three samples of prepared Belgian Bones. 
^. I, n. Hi. 
' Moisture 22-(i6 .. 16-49 .. 27-73 
*Orj:anic matter 10-12 .. 11-40 .. 8-81 
Tribasic phosphate of lime (bone-eartli) .. 50-94 .. 60*84 .. 51-32 
Carbonate of hme and alkalme salts .. .. 9-49 .. lO'OS .. 11-16 
Sand -79 .. 1-22 .. -98 
100-00 100-00 lOO'OO 
^Containing nitrogc'U .. .. 1-14 1-28 -86 
Equal to ammonia 1-38 1*55 1-04 
Sample No. II. is by far the best of the three, for it contains 
less moisture, and more nitrogenous matter and phosphates than 
the other samples. 
A still more valuable bone preparation than the preceding 
may be obtained in works in which patent size is made, not by 
boiling out the gelatine, but by dissolving the mineral portion 
of bones by means of cold diluted hydrochloric acid, and leaving 
the gelatinous tissue of bones behind. 
In works wherein this plan is adopted large quantities of an 
