1820.] the Atomic Theory. 291 



tian have 20 parts of oxygen, or 100 have 15"08. It is Hkewise 

 known that 100 parts carbonic acid require a quantity of base 

 having 36*267 oxygen; hence, 234'44 parts strontian have 

 36*267 oxygen, or 100 have 15*46, nearly the same as that from 

 the sulphate. The mean of both results is lo*27, the parts of 

 oxygen in 100 of strontian, vi^hich therefore consists in 100 

 parts of 



Oxygen 15*27- * 



Strontium 84*73 



100*00 



Now one integrant particle of strontian = 6*5 divided in the 

 proportion of 100 parts will give the weight of an atom of stron- 

 tium, which, as far as we can view it, must consist of one atom 

 of strontium + 1 atom of oxygen. Therefore, 100 strontian : 

 15*27 oxygen :: 6*5 strontian : 0*99275 oxygen in one integrant 

 part of strontian. A result so near 1, the weight of an atom of 

 oxygen, that it may be taken as such. Then 6*5 — 1 = 5*5 

 weight of an atom of strontium. 



49. Magnesium. — Magnesium maybe determined like barium 

 and strontium. The sulphate of magnesia, according to Berze- 

 lius, is composed of 



Sulphuric acid 100*00 



Magnesia 50*06 



and as there is but one combination of sulphuric acid and mag- 

 nesia known, we must consider it a binary, formed by the union 

 of 1 integrant particle of sulphuric acid, joined to 1 integrant 

 particle of magnesia. The integrant particle of sulphuric acid is 

 5; therefore, as 100 : 50*06 :: 6 : 2*51, the integrant particle of 

 magnesia. 



Further, 100 parts of sulphuric acid require a base containing 

 20 parts oxygen ; hence, 50*06 parts of magnesia contain 20 

 oxygen, or 100 contain 40. Now, to find the proportional part 

 of oxygen in 2*51, integrant particle of magnesia, the same as in 

 100, there is the proportion 100 : 40 :: 2-51 : 1. 



Magnesium = 1*5 atom of magnesium 



Oxygen 1*0 atom of oxygen. 



50. Yttrium. — According to the analysis of Berzelius, the 

 sulphate of yttria is composed of equal weights of acid and base ; 

 hence, the weight of an integrant particle of yttria is the same as 

 that of sulphuric acid = 5. 



Since we know but one combination of yttrium and oxygen, 

 and that oxygen is 1, yttrium must be 4. 



Moreover, since 100 parts sulphuric acid require as much base 

 as contains 20 parts oxygen, finding the oxygenofoiie integrant 

 particle in the same proportion as that of 50, we arrive at the 



t2 



