And herein lies his principal weakness. Hogarth declared: "There is only one school, that of nature." Reynolds: "There is only one doorway to the school of nature, and of that the old masters hold the key." The great men of old were for him the object of constant and conscious thought. He has endeavoured in his writings to propound a sort of general foundation of painting, has adopted the principles of the best painters in every land, was indefatigable in exploring the secrets of the old masterpieces, and has therefore won the praise of having set the English school, which had hitherto possessed no perfected tradition of painting, technically on firm feet. He was the founder of a scientific technique of painting derived from the ancients,--the Lenbach of the eighteenth century. Upon the mixture of colours, the gradations of light and shade, technically and æsthetically, no artist has pondered more than he, who knew the great Netherlanders, Rubens, Van Dyck, and Rembrandt, as well as, or better than, his particular favourites, the Italians. He made experiments all his life long to discover the stone of the wise Venetians; but he met with the same experience as Lenbach. And these experiments in the direction of the colour effects of the old masters were the bane of his pictures' durability. It was well said by Walpole: "If Sir Joshua is content with his own blemished pictures, then he is happier than their possessors, or posterity. According to my view, he ought to be paid in annual instalments, and only so long as his works last." And Haydon opined that "Reynolds sought by tricks to obtain results which the old masters attained by the simplest means." He endeavoured by means of asphaltum to give his pictures the artistic tones of the galleries, with the result that, to-day, the majority have lost every sign of freshness. [Illustration: REYNOLDS. BISHOP PERCY]