ARGON, A NEW CONSTITUENT OF TIIK ATMOSPHERE. '21 



it seemed possible that eacli giouj) was not contributing its pr(>i)er share, and even 

 that tliere might be a tiow in the wrong direction at the delivery end of one or two 

 of them. To meet this objection, tlie ari'angeiuent in parallel had to be aljandoned, 

 and for the remaining expei'iments 8 ])ipes were connected in simple sei-ies. The 

 poi'ous surface in operation was thus ivduced, but this was partly compensated for by 

 an im])roved vacuum. Two ex])eriments were made un<l<'i- the new conditions: 



Globe empty, Oct. 30, Nov. 5 2.82313 



Globe full, Nov. 3 ( 8 pipes) 50930 



Ordinary atmospheric nitrot;en 2.31016 



Difference + .00367 



Globe empty, Nov. 5, 8 2.82355 



Globe full, Nov. 6 (8 pipes) 5101 1 



2-31344 

 Ordinary atmospheric nitrogen 2.31016 



Difference + .00328 



The excess being lai'ger than befoi'e is doul)tless due to the gi'eatei' efficiency 

 of the atmolysing appai'atus. It should be mentioned that the above recorded ex- 

 periments include all that liave been tried, and the conclusion .seems inevitable that 

 "atmos[)heric nitrogen " is a mi.xture, and not a simple body. 



It was hoped that the concentration of the heavier constituent would be sufficient 

 to facilitate its pi-eparation in a pine state by the use of pi'epared air in substitution 

 for oidinaiy air in the oxygen apparatus. The advance of 8^ ing. on the 11 mg. 

 by which atmospheric nitivigen is heavier than chemical nitrogen, is indeed not to 

 be despised, and the use of pre[)ai'ed air would be convenient if the diffusion ap[)a- 

 ratus could be set up on a large scale and be made thoroughly self-acting. 



7. Negative Experiments to Prove that Argon is not Derived from Nitro- 

 gen FROM Chemical Sources. 



Although the evidence of the existence of ai'gon in the atmosphere, derived 

 fi'om the comparison of densities of atmos[)heric and chenncal nitrogen and from 

 the diff'usion expei-inients, appeared overwhelming, we have thought it undesirable 

 to shrink from any labor that would tend to complete the veiification. With this 

 object in view, an ex[)ei'iment was undertaken and carried to a conclusion on No- 

 vembei' 18th, in which 3 litres of chemical nitrogen, pi'epared from ammonium 

 uitrite, were treated with oxygen lu precisely the manner in which atmosphei'ic 



