EECEEATIVE SCIENCE. 



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coloured, of a darker gray, are to be placed 

 one with its edge against the edge of one of 

 the pale gray squares, and the other at a dis- 

 tance corresponding with the space between 

 the pale gray squares ; so that a row of four 



slightly in pencil on a slip of paper, each 

 stripe a quarter of an inch in width. Have 

 ready in a saucer an evenly -mixed wash of 

 any tint, with which lightly cover the whole 

 of this series of stripes. When all the 



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squares will be formed, the two middle squares 

 abutting, and the two outer squares, one 

 dark, the other pale, having spaces betweBn 

 them and the inner ones. When all this has 

 been properly done, the light gray abutting 

 on the dark gray will appear lighter than its 

 isolated fellow, and vice versa. 



The next step will be to demonstrate that 

 the modification is not equal over the entire 

 surfaces. By means of a card so cut as to 

 divide each of the middle squares into three 



parts, it will be found that the receding tints 

 are again modified by distance. As a result 

 of these two experiments, a third serves to 

 demonstrate the extent of contrast of tone ; 



and this it does in a very remarkable man- 

 ner. Ten stripes are to be indicated very 



stripes are dry, a second wash is to be placed 

 on all save the first stripe ; then a third wash 

 on all save the first and second ; then a 

 fourth wash on all the stripes but the first 

 three ; then a fifth wash, omitting the first 

 four, and so on to the end, when the tenth 

 stripe will be of a depth of ten washes, or 

 shades, and all the remaining stripes down 

 to the first will exhibit a gradual diminution 

 of intensity. The scale being completed, a 

 strange efiect wiU be at once apparent. In- 

 stead of a series oi flat tints, we have, as it 

 seems, a channelled or fluted band ; the edge 

 of each stripe being lighter against the next 

 dark edge, and darker against the next light 

 edge. The natural deduction of the facts 

 disclosed by these experiments will be that, 

 as the contrast of colour is an infinitely more 

 complex affair than the contrast of tone, so 

 the calculations required in the arrangement 

 or grouping of several hues must form a con- 

 siderable part of the artist's duty. Intricate 

 problems have to be solved before a pattern, 

 consisting of colours unequally distributed, 

 can be pronounced faultless. By reciprocal 

 modifications, each affording material for 

 study, it will be seen how, and in what degree, 

 red inclines to violet, yellow, and orange ; 

 yellow inclines to green, red, and orange ; 

 blue inclines to indigo, violet, and green, and 

 so on to the end of the seemingly endless 

 chapter. The knowledge of all these modi- 

 fications is as requisite to insure harmony in 



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