1820.] the Atomic Theory. 347 



compound ; it is easily obtained in a state of uniform purity, and 

 easily analyzed as a binary compound. It is the most suitable 

 measure of the power of the acids, and furnishes the most pre- 

 cise expression of the comparative neutralizing power of the 

 alkalies. 



The first thing, consequently, to be done was to determine 

 the number that should represent the relative weight of carbonic 

 acid, when oxygen is represented by 10. But it is a thing satis- 

 factorily proved that a determinate quantity of oxygen gives an 

 exactly equal volume of carbonic acid by uniting with carbon ; 

 and as the specific gravity of these gases is as 10 to 13*77, or 

 as 20 to 27*54, the weight of carbon is given exactly equal to 

 7*54, which in this combination with 20 oxygen forms the deut- 

 oxide. The protoxide of carbon is represented by 17'54. 



Carbonic acid being, therefore, represented by 27*54, it results 

 from the analysis of carbonate of lime, which, during calcination, 

 loses 43*7 acid, and leaves 56*3 base per cent, that these two 

 substances are combined in the proportion of 27*54 to 35*4G ; 

 and consequently that lime should be represented by 35*46, and 

 carbonate of lime by 63. 



If the series of decompositions be now continued in order to 

 verify the preceding analysis, 63 parts of carbonate of lime may 

 be dissolved in muriatic acid, and after evaporating the solution 

 to perfect dryness, we obtain 69*56 of muriate of lime ; and by 

 subtracting 35*46, weight of the lime, we get a difference of 34*1, 

 which represents the amount of dry muriatic acid. 



But lime is known to be a metallic substance united to oxygen; 

 this salt may consequently be considered under another point of 

 view, as a binary compound, an oxymuriate of calcium. In this 

 case we must transfer the 10 oxygen to the muriatic acid, and 

 the combination will read 44*1 oxymuriatic acid combined with 

 26*46 calcium, = 69*56. Or else, if we consider it as a chloride 

 of calcium, its value, on the scale of numbers, will still remain 

 69*56, whether we call it oxymuriatic acid, dephlogisticated 

 marine acid, or chlorine ; for the portion of matter added to the 

 calcium is always the same, and represented by 44*1. This 

 number consequently represents a mere fact, which is indepen- 

 dent of any theory ; but which enables us to estimate the propor- 

 tion of constituents in every muriatic combination, without 

 discussing their simple or compound nature, a question still 

 undecided. 



In like manner the muriates of potassa and soda will find their 

 place on the scale of equivalents, and the relative weights of 

 pure potassa and soda can be determined with the greatest 

 exactness, because they are not susceptible of an excess of 

 acidity, or of decomposition by heat. 



If to a quantity of muriatic acid, which can just dissolve 100 

 parts of carbonate of Hme, there be added 100 grs. of crystallized 

 carbonate of potassa, and that after this addition the acid can 



