Now let us look how, in the downward arc that we spoke of, Íshvara is imparting qualities. According to the nature of the vibrations that He sends and of the matter that answers to them will be the quality imparted. As to the idea that difference of vibrations implies a difference of manifestation, let me buttress myself on the great reputation of Sir William Crookes. He issued, two or three years ago, I don't remember the exact date, in 1896 I think, a table of vibrations, confined of course to the physical world; a very interesting table, giving a series of classified vibrations and pointing out which were known to science, and gave rise to what we call sound, light, electricity, and so on, the difference of vibratory frequency, and the subtlety of the matter in which the vibration was set up, giving rise to a particular impression, received and answered by a sensation in us. That is the principle which I am now applying to our system as a whole. According to the density of the matter will be the rapidity of the vibrations which that matter is capable of expressing; Íshvara sends out vibrations, and the mânasic matter, we will say, is thrown into corresponding vibrations or waves of a frequency identical with those of the life-impulse sent out from Him, so far as it is capable of responding, a limit being set by its fineness on the one side and by its density on the other. Its limit of fineness is the atom of the plane. Its limit of density is the coarsest aggregation of these atoms in the densest solid of the plane. If we take the physical plane for a moment, we have solid, liquid, gas, ether, finer ether, finest ether, and atoms. The lower five are related to the five senses in man as they are at present developed on the physical plane. These five correspond to the sense-organs and the senses that work through them, as is suggested in the names of the tanmâtras. The Solid is related to the sense of Smell; Liquid to the sense of Taste; Fire to the sense of Sight; Air to the sense of Touch; and A'kâsha to the sense of Sound. Nov these are not stated in the order given by the western scientist, but I have no time to go into the reason for the difference and to show you where his outer observation fails, because he is not able to trace beyond the limits of his senses into a finer working; in dealing with our Vâyu and A'kâsha, he classes them together, and his air is our Agni. These senses and their evolution belong to the upward arc. Coming downwards, Íshvara only gives the power to matter to respond to these particular vibrations, and these vibrations are connected on the physical plane with the sub-divisions that I have just mentioned, the different sub-divisions of matter, solid, liquid, gas, and so on, corresponding in the sense-organs to the senses.