C 47 J 



and boron : and muriatic acid gas is formed by the 

 union of chlorine and hydrogene. 



When smaller quantities of oxygene or chlorine 

 unite with inflammable bodies or metals, they form 

 substances not acid, and more or less soluble in wa- 

 ter ; and the metallic oxides, the fixed alkalies, and 

 the earths, all bodies connected by analogies ; are pro- 

 duced by the union of metals with oxygene. 



The composition of any compounds, the nature 

 of which is well known, may be easily learnt from the 

 numbers representing their elements ; all that is ne- 

 cessary, is to know how many proportions enter into 

 union. Thus potassa, or the pure caustic vegetable 

 alkali, consists of one proportion of potassium and one 

 of oxygene, and its constitution is consequently 75 

 potassium, 15 oxygene. 



Carbonic acid is composed of two proportions of 

 oxygene 30, and one of carbon 11.4. 



Again, lime consists of one proportion of calcium 

 and one of oxygene, and it is composed of 40 of cal- 

 cium and 15 of oxygene. And carbonate of 'lime ', or 

 pure chalk, consists of one proportion of carbonic 

 acid 41.4, and one of lime 55. 



Water consists of two proportions of hydrogene 

 2, and one of oxygene 15 ; and when water unites to 

 other bodies in definite proportions, the quantity is 17, 

 or some multiple of 17, /'. e. 34 or 51, or 68, &c. 



Soda, or the mineral alkali, contains two propor- 

 tions of oxygene to one of sodium* 



Ammonia, or the volatile alkali is composed of six 

 proportions of hydrogene and one of azote. 



