AROOiN. A NEW CONSTITUENT OF 11 IK ATMOSPHERE. 13 



could be seen, but after standing over water for an lionr or two tliese lines 

 became apparent. 



We now pioceed to give an account of the early experiments with magnesium. 



5. Early ExPKi'.i.MJiNT.s on W riiioiiAWAL of Nn'RooEX from An; i',v Means of 



ReuIIot Magnesium. 



It having been proved that nitrogen at a bright-red lieat was easily ab.sorbed 

 by magnesium, best in the foiin of turnings, an attempt was successfully made to 

 I'emove that gas fi'om tlic ii-iiluc. left aftei- ellminatinL'' ox\'gen from aii' by means 

 of red-hot copjiei'. 



The preliminary ex})eriment was made in the following manner: A combustion 

 tnbe, A, was tilled with magnesium turnings, packed tightly by pushing them in 



Fio. I. 



with a rod. This tube was connected with a second [.iece of condiustion tubing, B, 

 by means of thick-walled india-rubber tubing, carefidly wired ; B contained copper 

 oxide, and in its turn was connected with the tube C D, one-half of which con- 

 tained soda-lime, previously ignited to expel moisture, while the other half was 

 filled with phosphoric anhydride. E is a measuring vessel, and F was connected 

 with a gas-holder containing "atmospheric nitrogen." 



In beginning an experiment, the system of tubes, which was heated with hnig. 

 flame burners, was pumped empty ; a little hydiogen was formed by the action of 

 the moisture in the tube on the metallic magnesium ; it was oxidized by the coppei- 



