Not one is constant, but everything is changing, matter eternally concreting and disintegrating. So it is with the mind. Matter is represented by the ether; when the action of Prana is most subtle, this very ether, in the finer state of vibration, will represent the mind and there it will be still one unbroken mass. If you can simply get to that subtle vibration, you will see and feel that the whole universe is composed of subtle vibrations. Sometimes certain drugs have the power to take us, while as yet in the senses, to that condition. Many of you may remember the celebrated experiment of Sir Humphrey Davy, when the laughing gas overpowered him — how, during the lecture, he remained motionless, stupefied and after that, he said that the whole universe was made up of ideas. For, the time being, as it were, the gross vibrations had ceased, and only the subtle vibrations which he called ideas, were present to him. He could only see the subtle vibrations round him; everything had become thought; the whole universe was an ocean of thought, he and everyone else had become little thought whirlpools.