HISTORICAL INTRODUCTION. 



11 



CHARACTERS. 



(DO Nitrous oxide 



Ethers 



Carburetted hydrogen 



OCDO Nitric acid 



RELATIVE WEIGHTS. 



16-5 



7 

 18 



QUATERNARY COMPOUND. 



CD Oxv-nitric acid 

 O 



QUINQUINARY COMPOUND. 



G)Q(DO Nitrous acid 



SEXTENARY COMPOUND. 



Alcohol 



O CD 



00 







SEPTENARY COMPOUND. 



Nitrate of ammonia 



24-5 



29-5 



23-5 



31-5 



Such was the view of the subject, which Mr. 

 Dalton had taken before the month of August, 

 1804. Unless my recollection fails me, Mr. 

 Dalton's theory was originally deduced from his 

 experiments on olefiant gas and carburetted 

 hydrogen. He found both composed of carbon 

 and hydrogen ; but the carbon in each being 

 considered as the same, he found the hydrogen 

 in the latter gas twice as much as in the former. 

 This induced him to determine the ratios of 

 these constituents in numbers, and to consider 

 the olefiant gas as a compound of 1 atom carbon 



