317 



obtaining carbonate of ammonia; or in small particles from 

 the lathe of the bone turner. In all these states bones afford 

 phosphate of lime ; but there are other sources, the most 

 abundant of which are the horns of certain animals. The re- 

 sult of some trials was stated, from which it appeared that 

 recent sheep bone (the leg), when burned to whiteness, af- 

 forded 38-71 per cent, of earthy matter; and recent ox-ribs, 

 37"14 per cent. In neither case were the moisture and fatty 

 matter previously withdrawn, and this is the cause of the diffe- 

 rence between these estimates and those that have been hi- 

 therto published. With regard to horn, the incineration to 

 whiteness of shavings of hartshorn returned, on an average of 

 many trials, 62 per cent, of phosphate of lime. 



These different forms of bone and horn present us with 

 phosphate of lime, in states which possess different advan- 

 tages; some hold out the inducement of cheapness, some of 

 facility in employing them ; all of them answer the purpose. 

 Hartshorn shavings, beside phosphate of lime, contain a light, 

 highly nutritious, and most agreeable jelly, which has found 

 its way to the kitchen, the nursery, and the sick room, and 

 which may be preserved after the shavings have yielded their 

 earth. 



In order to remove the animal matter from the earthy por- 

 tion of bones, the process of calcination is resorted to, but 

 this is uneconomical and troublesome. It is better and easier 

 to withdraw the earthy portion from the animal matter by 

 digestion in very dilute nitric acid ; the earthy salts will be 

 thus dissolved away, and the cartilage will remain unaltered. 

 The phosphoric acid may be withdrawn from the solution by 

 means of a salt of lead. Chloride of lead does not succeed, 

 the nitrate will not be more successful, but the acetate answers 

 perfectly. The cartilage which remains may be converted to 

 a variety of purposes, as for making glue and size. 



On economical grounds, bones, not burned, but crushed 

 between rollers for agricultural purposes, were recommended 

 2 B 2 



