528 Lord Bayleigh [April 5, 



that, if there be more than one inert ingredient in the atmosphere, 

 at any rate the second ingredient is not contained to a greater extent 

 than t ^q part. 



I must not wait too long over the experiment. Mr, Gordon tells 

 me that a certain amount of contraction has already occurred ; and 

 if we project the U upon the screen, we shall be able to verify the 

 fact. It is only a question of time for the greater part of the gas 

 to be taken up, as we have proved by preliminary experiments. 



In what I have to say from this point onwards, I must be under- 

 stood as sj)eaking as much on behalf of Professor Ramsay as for 

 myself. At the first, the work which we did was to a certain extent 

 independent. Afterwards we worked in concert, and all that we 

 have published in our joint names must be regarded as being equally 

 the work of both of us. But, of course, Professor Earn say must not 

 be held responsible for any chemical blunder into which I may 

 stumble to-night. 



By his work and by mine the heavier ingredient in atmospheric 

 nitrogen which was the origin of the discrepancy in the densities has 

 been isolated, and we have given it the name of " argon." For this 

 jmrpose we may use the original method of Cavendish, with the 

 advantages of modern appliances. We can procure more powerful 

 electric sparks than any which Cavendish could command by the 

 use of the ordinary Ruhmkorff coil stimulated by a battery of Grove 

 cells ; and it is possible so to obtain evidence of the existence of 

 argon. The oxidation of nitrogen by that method goes on pretty 

 quickly. If you put some ordinary air, or, better still, a mixture of 

 air and oxygen, in a tube in which electric sparks are made to pass 

 for a certain time, then in looking through the tube, you observe 

 the well-known reddish-orange fumes of the oxides of nitrogen. I 

 will not take up time in going through the experiment, but will 

 merely exhibit a tube already prepared (image on screen). 



One can work more efficiently by employing the alternate currents 

 from dynamo machines which are now at our command. In this 

 Institution we have the advantage of a public supply ; and if I pass 

 alternate currents originating in Deptford through this Ruhmkorff 

 coil, which acts as what is now called a " high potential transformer," 

 and allow sparks from the secondary to pass in an inverted test tube 

 between platinum points, we shall be able to show in a comparatively 

 short time a pretty rapid absolution of the gases. The electric 

 current is led into the working chamber through bent glass tubes 

 containing mercury, and provided at their inner extremities with 

 platinum points. In this arrangement we avoid the risk, which 

 would otherwise be serious, of a fracture just when we least desired 

 it. I now start the sparks by switching on the Ruhmkorff to the 

 alternate current supply ; and, if you will take note of the level of 

 the liquid representing the quantity of mixed gases included, I think 

 you will see after, perhajis, a quarter of an hour that the liquid has 



