200 ACIDIFJABLE COMBUSTIBLES. 



white insoluble powder, while a transparent 

 colourless liquid remained, holding nitrate of 

 soda in solution. A drop of this liquid was put 

 into a watch glass, and mixed with a drop of 

 solution of sulphate of soda. No precipitation 

 or opalescence took place, showing that the li- 

 quid contained no sensible quantity of lead. 

 Another drop of the same liquid being put into 

 another watch glass, was tested in the same 

 manner with nitrate of lead, without being in 

 the least affected, showing the absence of any 

 sensible quantity of phosphoric acid. This ex- 

 periment was repeated several times with exact- 

 ly the same result. 



From the preceding experiment it is obvious, 

 that the oxide of lead in 20*75 grains of nitrate 

 of lead, just neutralizes the phosphoric acid in 7*5 

 grains of anhydrous phosphate of soda. In like 

 manner, the nitric acid of the former salt just 

 neutralizes the soda of the latter. But 20'75 

 grains of nitrate of lead are composed of 



Nitric acid . 6-75 

 Protoxide of lead 1 4- 



20-75 



Numbers which are equivalent to the atomic 

 weights of nitric acid and protoxide of lead. 



Fourteen grains of protoxide of lead require 

 for saturation, a quantity of phosphoric acid, 

 equivalent to an atom ; 6*75 grains of nitric 



