In the Science of Acoustics, _Sound_, the pure _Phonos_, is the _Something_, the _Reality_, as it is denominated by Kant, the _Positive_ Factor of Speech. _Silence_ is the relative _Nothing_, the Negation, so called by Kant, the _Negative_ Factor of Speech. The Silences, or Intervals of Rest which intervene between Sounds (and also between Syllables, Words, Sentences, and still larger divisions of Speech), are only so many successive reappearances of this _negative_ element. Silence, the Nothing of Sound, is, in fact, in the most radical aspect of the subject, one entire half or hemisphere or equal Factor of the whole of Speech or Music. Josiah Warren, the author of a work entitled 'Music as an Exact Science,' is the only writer I have noticed who has had the discrimination _distinctively_ to recognize Silence as one of the Elements of the Musical Structure. _Impliedly_ it is, however, always so recognized. The Silences intervening between tones _tunewise_, or in respect to altitude, are, in Musical Nomenclature, denominated _Intervals_. _Timewise_ Silences, or those which intervene between Tones rhythmically considered, are called _Rests_. The Intervals of Silence between Syllables and Words, in Oral Speech, are represented in the printed book by what the Printer calls _Spaces_, which are _blank_ or _negative_ Types interposed between the positive Types expressive of Sounds. This term _Space_ or _Spaces_ carries us to the analogous Total Space or Blank Space and intervening reaches of Space between the Planets, Orbs or Material Worlds, the former the corresponding _Nothing_ of the total Material Universe of which these worlds are the _Something_; as exhibited in the demonstrations of UNIVERSOLOGY. In the Domain of Optics, covering the Phenomena of Light, Shade and Color, _Light_ is the _Positive_ Factor or _Something_, and _Darkness_ the _Negative_ Factor or _Nothing_. _Light_ is, therefore, the analogue of _Sound_, and _Darkness_ the analogue of _Silence_. That is to say, each of these two, Silence and Darkness, denote the absence, the lack, the want or the negation of the opposite and _Positive_ Element or Factor. So in Thermotics, the Science of Heat, _Heat_ itself is the _Positismus_ or _Something_ of the Domain; and _Cold_ the _Negatismus_ or Correlative _Nothing_. _Heat_ is, consequently, the analogue of _Sound_ and _Light_; while _Cold_ is the analogue of _Silence_ and _Darkness_.