40S On the Origin of the Atomic Theory. 



tliey enter the alburnum. They may be compared with the 

 seed when it is first di-covered in the seed-vessel, and will give 

 positive prot,f that it was the seed in the root, since the same 

 shoot will be discovered in both. 



Fig. 6. The radicle of the Lis. 



Fig-. 7 and 8. Heart of the seed of the fir when divided, 

 throwing out its germ or flower, and growing on the glass : it is 

 impossible in this part to draw the flowers small enough to imi- 

 tate even the magnified specimens. 



LXXXII. On the Origin nf the Atomic Theory. By William 

 HiGGi^s, Esq. 



[Concluded from p. 371.] 



J- KE next subject which the Doctor introduces, after g-iving my 

 theory toDalton, relates to the doctrine of Volumes discovered as 

 he tells us by M. Gay Lussac, and published in the year 1 809. He 

 found " that they follow a very simple law in their combinations; 

 that one volume of one gas always unites either with one volume 

 of another gas, or with two volumes, or with three volumes." 

 He then adduces a few examples to support this law. 



" Gay Lussac also showed that the diminution of volume which 

 takes place on the combination of these gases, follows as sim- 

 ple a law as the volumes in wliich they combine. In nitrous 

 gas the oxygen and azote undergo no condensation; accordingly 

 the specific gravity of nitrous gas is the mean between that of 

 oxygen and azote. Frequently one of the two gases retains its 

 bulk r.naltered, while the other totally disappears." 



'' I'his curious law discovered by Gay Lussac, vvlien coupled 

 with the doctrine of Mr. Dalton, shows us, that there exists a 

 very simple relation between the weight of the atoms and the 

 bulk of the gaseous bodies. Accordingly, the weight of the 

 atoms of these bodies may be deduced with sufficient accuracy 

 from their specific gravity. This method was employed both 

 by Sir H. Davy and Dr. Wollaston." 



The theory of volumes of Gay Lussac was published after 

 Dalton's Atomic Theory, therefore the latter could derive no 

 advantage from it. Now the doctrine of the proportions in 

 which particles unite to particles, or atoms to atoms, could only 

 be deduced from a previous knowledge of the specific gr.ivity of 

 simple gases and of their compounds in the gaseous state, and 

 of the proportions in which they imite volume to volume. The 

 whole of my Atomic System was founded on those principles, 

 and without this preliminary knowledge I could not advance a 



single 



