1886.1 '^l [Oliver. 



and the transmitted nerve stimulus ; the healthy peripheral nerve tip re- 

 turning to its "energy-equivalent" or normal nerve power, the moment 

 that the specific energy separated by the received natural vibration has 

 been forwarded for transmission and recognition, whilst the transmitting 

 filament and excited cerebral expansion regain their normal conditions the 

 moment that the energy has passed them. After the consummation of such 

 an action, the filament is again ready for any other natural color- vibration. 

 In other words, a natural wave motion equal to natural color sets a peri- 

 pherally placed life force into an equivalent life motion, which is trans- 

 mitted to a central organ of perception where it is perceived. It is the action 

 of natural wave motion upon sensory life motion, the life motion being 

 produced by a loss and restitution of working material, i. e., a chemico- 

 vital action. Thus to see red, the nerve is first supposed to be charged to 

 its normal physiological condition by its inherent vitality and sensitizing 

 material. Vibrations of say five hundred trillions per second (some natural 

 red color), are allowed to be thrown upon this sensitized tip. To see the 

 color, the peripheral negative (an unused energy equal to the commencing 

 sensation of a "green") must be allowed to rest, by the separation of a 

 quantity of nerve-force equal to a supposed red energy, from the "energy- 

 equivalent," through the excitation of the impinging ray. This separated 

 specific energy is transmitted and perceived. The moment that the red- 

 energy has left the nerve tip, the terminal is again charged to its "energy- 

 equivalent" and is ready to receive any other color-vibration that may be 

 cast upon its surface. Each and every natural color causes the separation 

 of a specific energy equal to itself, which is properly transmitted and cor- 

 rectly perceived, if the conducting and central nerve structures be normal 

 and intact. 



Based upon this theory, the following conclusions in reference to sub- 

 jective after-color may be formulated : 



First. Definition of Subjective After- Color. — Color-perception resulting 

 directly from provoked remaining nerve-energies. The exciting stimulus 

 may be either peripheral or central ; the former is produced from the ex- 

 ternal world or natural light stimulus, and the latter from some internal 

 stimulation, either in the visual apparatus or in the cerebrum beyond it. 



Second. Cause of Subjective After-Color. — "Complementary Color " is 

 caused by the presentation of a second stimulus, either external or internal, 

 of greater power than the remaining nerve-energy left from a previous 

 color-action, before the visual apparatus has had time to return to its nor- 

 mal condition. 



Third. Equivalence of Result. — The result is always equal to the differ- 

 ence between the amount of nerve-energy separated by the primary 

 stimulus and the normal condition (energy equivalent) of the impressed 

 portion of the optic- nerve filament. 



Fourth. Passing Subjective After-Colors. — Two varieties ; non-reexposed 

 and reexposed. The former depends upon the fact that the primary stim- 



