CONSTITUENTS OF BONE. 133 



also the alkaloids. On this account it is used for decolor- 

 izing liquids as well as for an antidote in cases of poison- 

 ing by strychnine and some other alkaloids. 



296. Fill a dry test-tube one-third full of fragments 

 of dry bone, fasten it horizontally by the upper end in a 

 clamp, and heat, at first gently, then to as high a tem- 

 perature as possible without softening the glass, moving 

 the burner so as not to heat it in one spot. The organic 

 matter is decomposed. First water is given off, then am- 

 monia. Test this with a piece of red litmus-paper. A n 

 oily or tarry mixture distills off with inflammable gases. 

 When the gas has been expelled the mineral matters of the 

 bone remain mixed with carbon. 



297. Take a piece of this and heat it in the air, hold- 

 ing it with the forceps or a piece of wire. The carbon 

 burns away, leaving only the mineral matters as a brittle 

 mass. 



298. Dissolve the bone-ash in dilute nitric acid. 

 Notice that carbonates are present, as shown by the effer- 

 vescence of carbon dioxid gas. 



299. Test a portion of the solution for phosphoric 

 acid, which is present in the phosphates, by making it 

 strongly acid with nitric acid, then adding ammonium 

 molybdate and warming gently. A yellow precipitate 

 shows phosphoric acid. 



300. Test another small portion of the solution for 

 chlorids with silver nitrate. They give a milkiness or a 

 white precipitate, but are present in very small quantities. 



301. Test the remainder of the nitric acid solution 

 for calcium and magnesium after removing the phosphoric 

 acid in the following manner: Add a few drops of ferric 

 chlorid to the solution in a beaker. The iron unites with 

 the phosphoric acid, which was held by the calcium and 



