People are always talking about 'incidentals'; but nothing is incidental in a picture, everything is indispensable to the whole effect, so nothing must be neglected. If a man can give value to the main part of his composition only by negligent treatment of the subordinate portions, his work is in a bad way. Everything must and can be carefully executed, without the different parts obtruding themselves on the eye. The proper subordination of the parts to the whole is not achieved by neglecting incidental features, but by correct grouping and by the distribution of light and shadow.