snake, and in the hollows in the negative one; the snake itself consists of small bead-like bodies, eleven of which interpose between the larger brilliant spots.  On raising these bodies to E 3 the snakes break up, each bright spot carrying with it six beads on one side and five on the other; these twist and writhe about still with the same extraordinary activity, reminding one of fire-flies stimulated to wild gyrations.  It can been seen that the larger brilliant bodies each enclose seven ultimate atoms, while the beads each enclose two.  (Each bright spot with its eleven beads is enclosed in a wall, accidentally omitted in the diagram.) On the next stage, E 2, the fragments of the snakes break up into their constituent parts; the positive and negative bodies, marked d and d’, showing a difference of arrangement of the atoms contained in them.  These again finally disintegrate, setting free the ultimate physical atoms, identical with those obtained from hydrogen.  The number of ultimate atoms contained in the gaseous atom of oxygen is 290, made up as follows:—­

  2 in each bead, of which there are 110: 
  7 in each bright spot, of which there are 10;
  2 x 110 + 70 = 290.

When the observers had worked out this, they compared it with the number of ultimate atoms in hydrogen:—­

  290 / 18 = 16.11 +

The respective number of ultimate atoms contained in a chemical atom of these two bodies are thus seen to closely correspond with their accepted weight-numbers.

It may be said in passing that a chemical atom of ozone appears as an oblate spheroid, with the contained spiral much compressed and widened in the centre; the spiral consists of three snakes, one positive and two negative, formed in a single revolving body.  On raising the chemical atom to the next plane, the snake divides into three, each being enclosed in its own egg.

The chemical atom of nitrogen was the third selected by the students for examination, as it seemed comparatively quiet in contrast with the ever-excited oxygen.  It proved, however, to be the most complicated of all in its internal arrangements, and its quiet was therefore a little deceptive.  Most prominent was the balloon-shaped body in the middle, with six smaller bodies in two horizontal rows and one large egg-shaped one in the midst, contained in it.  Some chemical atoms were seen in which the internal arrangement of these contained bodies was changed and the two horizontal rows became vertical; this change seemed to be connected with a greater activity of the whole body, but the observations on this head are too incomplete to be reliable.  The balloon-shaped body is positive, and is apparently drawn downwards towards the negative egg-shaped body below it, containing seven smaller particles.  In addition to these large bodies, four small ones are seen, two positive and two negative, the positive containing five and the negative four minuter spots.