1320.] the Atomic Theory. 349 



so that carbonic acid being 27-54, and lime 35-46, carbonate of 

 lime is placed at 63. 



In like manner, the weight of oxygen being 10, the propor- 

 tional weight of sulphur is 20, azote 17-5, &c. and by simple 

 addition of the proportional weights of the single bodies on the 

 scale we get those of the compounds. Magnesia is 23, sulphuric 

 acid 50, and sulphate of magnesia 75, on the scale ; therefore, 

 75 dry sulphate of magnesia is composed in the proportion of 25 

 base and 60 acid. 



Carbonic acid being 27-54, and ammonia 21-5, subcarbonate 

 of ammonia is placed at 49-4, and is composed in this proportion. 



Muriatic acid gas being 45-5, and ammonia 21-5, they combine 

 in the gaseous state, and muriate of ammonia is 67. 



Oxide of silver being 145-5, and dry muiiatic acid 34-5, 

 muriate of silver is 180. 



Oxide of copper is 50, and sulphuric acid is 50, but crystallized 

 sulphate of copper contains water of crystallization, and oxygen 

 being 10, the proportion in which water stands to it is 11*4, 

 which, multiplied by 5, the proportion in which the water^ of 

 crystallization stands to dry sulphate of copper, makes 57 added 

 to 100 = 157, the number on the scale. 



Oxide of zinc is 51, and sulphuric acid 50, which + 79 water 

 of crystallization, makes 180, the number on the scale. 



Lead on the scale is placed opposite to 129*8 in this position of 

 the slider. The addition of 10 oxygen and 34-4 dry muriatic 

 acid give 174, the number for muriate of lead on the scale. 



Lastly, mercury is 126-6, and oxygen being 10, dry muriatic 

 acid 34-4, as above, corrosive muriate of mercury is placed 

 opposite to 170 on the slider. 



Second Position of the Slider. 



If it be required to find the weights of the constituents of a 

 given compound, say 100 oxide of iron, the slider is to be moved 

 until 100 comes against oxide of iron. Then the numbers on 

 the slider opposite the constituents, oxygen and iron, is the 

 quantity of each in 100 of the compound. ' For oxygen, it is 22-5, 

 and for iron 77-5. 



It also gives the constituents of sulphate of iron per cent, as 

 composed of oxide of iron 25-8, sul. acid 28-2, water of crystalli- 

 zation 46. 



Let there be given a quantity of any salt, how much will be 

 given of any other, having a constituent the same as one in the 

 given salt? 



Let bicarbonate of soda be the salt given. When the scale is 

 adjusted, 100 being opposite to bicarbonate of soda, and salts 

 having the same base (soda) are sought for, it will be seen imme- 

 diately that these 100 parts bicarbonate contain as much soda as 

 84-5 dry sulphate of soda ; 69-5 muriate of soda ; 63 subcarbon- 

 ate of soda ; 101 nitrate of soda, &c. 



