f 825 ] 



increase of weight should be calculated as being due to the 

 weight of CaCO 3 in one gram of bone-meal. 



(6) Nitrogen. One gram of bone-meal is weighed 

 out on a watch-glass. A strong tube 12 inches or so in 

 length, drawn out into a closed point at one end and open 

 at the other end is taken. It is filled with hot soda-lime 

 (i.e. 2 equivalents of CaO to one of NaHO, powdered and 

 heated on an iron pot). This is emptied out on a clean 

 porcelain bason, except about i inch. A funnel is held with 

 the left hand, the lower end being closed with the index 

 finger, a little of the soda-lime is poured on the funnel, 

 then the one gram of bone-meal with more than half the 

 remaining quantity of soda-lime, which are carefully mixed 

 together in the funnel with a Spatula. Then the finger is 

 let go, and the contents of the funnel emptied into the 

 tube. With the remaining soda-lime the watch-glass is 

 cleaned out thoroughly with the help of a feather, and also 

 the funnel. An inch of asbestos plug is then introduced ; 

 and then the Sulphuric Acid bulb containing one pipette- 

 ful (20 c. c.) of the standard H 2 SO 4 is also fixed on with 

 a cork. This is put on the furnace. Whether the apparatus 

 is air-tight or not is tested with a spirit lamp. The heating 

 commencing at the bulb-end, takes about 2 hours. The 

 quantity of H 2 SO 4 neutralized by NHs is then ascertained. 



1,406. The following figures obtained in course of an 

 analysis of a sample of bone-meal will illustrate how the 

 analysis is actually worked out : 



Moisture and organic matter : 



Weight of crucible + raw bone-meal= 30^336 grammes 

 crucible alone =29*336 



/.Weight of raw bone-meal taken = i gramme 

 Weight of crucible + raw bone-meal =30*33600 ,, 

 ,, Crucible + ignited residue =29 95825 



.'. Weight of organic matter + moisture= '37775 grammes 



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