236 MEMOIR OF DR. DALTON, AND 



circle, with some distinctive mark; and the combinations 

 consist in the juxtaposition of two or more of these; when 

 three or more particles of elastic fluids are combined together 

 in one, it is to be supposed that the particles of the same kind 

 repel each other, and therefore take their stations accordingly." 



In the figures to which he refers above he has shewn 

 to us how vividly he formed these ideas, that they ^ere^ 

 no mere fancies which had passed through his brain, but 

 distinct impressions, ready prepared for utterance. No doubt 

 is left upon our minds as to his opinions, which are, that 

 every piece of matter, even the smallest, must follow the 

 laws of the largest ; that when pounds of matter unite, the 

 atoms contained in them must unite also, until we come to 

 the fact that only atoms can really be said to unite. Now as 

 the conception of any fraction of an atom is a contradiction 

 and impossible, they must constantly unite as wholes, and the 

 proportion will be constant. If constant in the smallest 

 quantities, then so in the largest, explaining the permanency 

 of the constitution of bodies so much disputed, and making it 

 a law of nature. If two compound bodies unite, the same 

 law is followed out. 



He then gives instances of combination, and adds to his 

 explanation a plate of the " arbitrary marks or signs chosen to 

 represent the several chemical elements or ultimate particles." 



He gives twenty atomic weights and seventeen analyses of 

 gases and acids. His atomic weights are — 



Hydrogen, its rel. weight. . 1 



Azote 5 



Carbone 5 



Oxygen 7 



Phosphorus 9 



Sulphur 13 



Magnesia 20 



Lime 23 



Soda 28 



Potash 42 



Strontites 46 



Barytas 68 



Iron 38 



Zinc 56 



Copper 56 



Lead 95 



Silver 100 



Platina 100 



Gold 140 



Mercury 167 



