Ill M. NOBILI ON COLOURS, AND ON A NEW CHROMATIC SCALE 



general law of the harmony of the eye will be this : That the corre- 

 sponding colours in the Table hereafter mentioned will be in harmony 

 with one another." 



" In fact, if the organ of vision, after having been fixed on an orange 

 colour, directs itself spontaneously, and uninfluenced by any external 

 impulse, towards the indigo, or vice versa ; or if in nature a violet- 

 coloured hyacinth is placed beside a jonquil, and the optic axis is turned 

 from the one flower upon the other, the centre of the retina passes over 

 that succession of colours which is demanded by the nature of the or- 

 gan and cannot be felt but with pleasure and satisfaction. These two 

 colours harmonize, because the one leads to the other ; and, for the con- 

 trary reason, if the eye has to pass from one colour to another, not cor- 

 responding with it in the table, it will necessarilj' have to make a dis- 

 agreeable effort, because it will find itself in a position not in harmony 

 with its former state. If the ocular harpsichord of Caslet were pos- 

 sible, the modulation of the colours would be executed on it accord- 

 ing to the principle just laid down*." 



I will not deny that the aptitude of the retina to cause an imaginary 

 to arise from a real colour is of some account in the efiect produced by 

 colour. I am even inclined to believe that colours attentively observed 

 are, by this tendency of the organ, associated with a sentiment and 

 endowed with an expression which they could not otherwise possess. 

 This however would be a species of melody and not of harmony. 



Harmony is an instantaneous effect produced on the mind by several 

 colours united altogether independent of the development of imaginary 

 colours. Before this development can take place, the eye must be fixed 

 for some time on a real colour; nor is this all, it is also necessary that 

 the real colour should be seen in a bright light. Noav, when I have 

 one or two coloui's before my eyes, I can judge of their harmony with- 

 out being obliged to look at them for a long time or requiring a veiy 

 bright light. If I observe them for a single instant, my judgement is 

 already pronounced, with the same promptitude with which the ear 

 decides when it is affected by the hai'mony of sounds. Suppose for a 

 moment that real sounds had their corresponding imaginary sounds, 

 and the latter were determined when the ear had been for some time 

 affected by a single quality of sounds suitably sustained. In the first 

 place, these imaginary sounds could make no impression except in the 

 particular case in which the notes are sustained for some time ; but if 

 we suppose that they accompanied the real sound necessarily and in 

 eveiy circumstance, they w'ould not be in harmony with it; they would 

 be perceived an instant after it, and would produce melody. 



When a particular colour is ill-assorted with another, the eye is of- 

 fended, as the ear is hurt by a discord. If we pass from one of these 



• Venturi, Recherche Physique sur les Couletirs, for which the prize of the 

 Italian Society was awarded. Modena, 1802. 



