vol's 



Figure 6. 



nycho- 



cliloric 



acid 



gas. 



2 vol's. 



.i vol's. 



2 vol's. 

 Figure. 7. 



Hydrogen 



Hydrogen 



Hydrogen 



Ammo- 

 nia 



3 vol's. 



Figure 8. 



Common air. 

 Figure 9. 



ERRATA.— Page 42o, in 15th line, for " fartherest." read " fnrthcst." Page 428, 

 in 9th line, for " the sonrce," read ''asonrce"; on 32d lino, for "volumes," read 



" atoms." Page 430, in 5th line, read " The four thick lines represent "; in 12th 



line, read after " oxygenated water," Ih Oo clt. Page 431, in line 11, the words 



" common air " arc erroneously repeated. 



(429) 



