100 Tin-; Ottawa Naturalist. 



impossible to give an account of all the experiments these scientists 

 mule in order to make sure that the discrepancy in weight already 

 referred to was not due to impurities. Suffice it to say that all possibility 

 of the nitrogen prepared from chemical compounds being a mixture, was 

 shown by varied and careful experiments to be without any foundation. 



methods of preparation 





Of the elements that combine directly with nitrogen, magnesium * 

 was chosen as the best. When nitrogen is passed over this metal in a hard 

 glass tube heated to redness, absorption takes place with incandescence. 

 The authors state that from 7 to 8 litres of nitrogen can be absorbed in a 

 single tube. The nitride so formed is a porous, dirty orange coloured 

 substance. Red hot magnesium therefore was used to absorb or gel 

 rid of the nitrogen, while red hot copper was similarly used to combine 

 with the oxygen of the air experimented upon. 



The method of Cavendish, by " sparking" nitrogen with oxygen in 

 the presence of an alkaline liquid, was employed by the authors in then- 

 earlier experiments. This finally resulted in obtaining a small quantity 

 t residual gas, proportional to the volume of air operated upon, which 

 ould not be further oxidised. Its spectrum proved that it was not 

 nitrogen. It was, in fact, the newly discovered element, argon. 



The abstract then gives the details of an experiment in which the 

 oxygen of the air under trial was absorbed by red copper. This left a g 

 of the density of 14.88. This, as the investigators say, while not con- 

 clusive, was encouraging. Then by passing backwards and forwards such 

 "atmospheric nitrogen" over red hot magnesium tiny obtained alter 10 

 days about 1500C.C. of this heavier gas. This was treated with a large num- 

 ber of chemical absorbents to purify it, and as a result they had 200 c.c. 

 "I a gas of the density of 16.1. Still further absorption yielded a gas with 

 1 density of 19.09. This on " sparking " with oxygen eliminated the last 

 traces of nitrogen, the remaining gas having 20.0 as its density. This 

 showed, by spectrum analysis, lines not reconcilable with any known 

 element. 



The method of atmolysis was then tried. Atmospheric nitrogen, 

 after separation of oxygen by red hot copper, was diffused through a 

 number of tobacco pipe stems, The nitrogen so obtained was denser 



