1 S8 Solubility of Phosphatic Materials. 
Whilst speaking; of ivorj-dust and its uses, 1 am anxious to 
put purchasers of this refuse on their guard, for its powdery state 
admits of the ready admixture of chalk, sand, ground gypsum, 
and vegetable ivory, which adulterants are not readily detected 
by the look or feel. 
Vegetable ivory in appearance closely resembles bone-shavings 
or Ivory-dust, but, being a vegetable production of the samo 
chemical character as woody fibre, it has as a manuring agent 
just as little value as sawdust. 
Some time ago an adulterated sample passed through my 
hands, and on analysis yielded results which, for sake of com- 
parison, I place side by side with the composition of the pure 
substance : — 
Composition of Ivory-dust. 
Adulterated with Gypsum Good Ivory- 
atid Vegetable Ivory. dust. 
Moisture 10-01 .... 13-12 
'Organic matter 40-40 .... 26-12 
Phosphates of lime and magnesia (bone-eartli) .. 28-01 .... 53-74 
Carbonate of limo 2-87 .... 5-39 
Alkaline salts -77 .... '78 
Sulphate of lime (sypsum) 14-44 .... none 
Sand .. .. .'. .3-50 .... -85 
100-00 100-00 
*Containing nitrogen 2*15 3-28 
Equal to ammonia 2-61 3-98 
Besides gypsum a considerable quantity of vegetable ivory was 
added to the adulterated ivory-dust, and in consequence both the 
amount of nitrogen and of bone-earth was much less than in the 
genuine commercial article. 
Bones submitted to high-pressure steam may afterwards be 
ground to a powder almost as fine as coarse flour, and, when the 
process has been properly carried out, will be found not to have 
lost much nitrogen. Such a sample of steamed bone-meal was 
used in experiments on the solubility of bone materials, and 
yielded on analysis in 100 parts : — 
Composition of Bone-meal [steamed). 
Moisture 9' 11 
'Organic matter 21-25 
Phosphates of lime and magnesia (bone-earth) ()l-94 
Carbonate of lime 4-68 
Alkaline salts 1-70 
Sand 1-32 
100-00 
*Containiiig nitrogen 2*84 
Equal to ammonia 3* 45 
