Of Bol’s capacity in portrait-painting a good example is _Portrait of a Mathematician_, in the Louvre. He is shown resting one arm on a balustrade, the body, in black with a white collar, being in profile, while the gray-haired head, covered with a black cap, is facing round to the spectator, as he points with a ruler to a geometrical figure on a blackboard. It is a piece of honest characterization, blending vivacity and dignity. In quite a different vein is his portrait of a girl in profile in the Liechtenstein Gallery. She has soft pale blond hair, and the figure is enveloped in that yellow tonality which marks Bol’s transition from the Rembrandtesque manner to his later one. The girl with her protruding forehead bears a striking resemblance to a girl, painted by Rembrandt, in Room VI of the same gallery, and a comparison of the two pictures offers an interesting commentary upon the essential difference between the master and one of his most successful pupils.
Among five portraits by Bol in the Munich Pinakothek No. 338 may be specified as particularly handsome. It is that of a man with dark-brown hair and a mustache and imperial of lighter hue, possibly Govert Flinck. He wears a black cap and cloak and leans his arm upon a table. The following number in the catalogue is allotted to a portrait of this man’s wife. She is shown as far as the waist, where her hands are folded, the body full front, the head a little to the left. The face is beautifully modeled in clear flesh-tones, surrounded by golden-brown hair in ringlets. Beneath her white stomacher is a dull-red gown with olive sleeves. Thus the color-scheme is Rembrandtesque, with an envelop of warm amber atmosphere, while the serious sympathy with which the characterization has been rendered would not be unworthy of Bol’s great master.
Unfortunately, Bol by no means maintained this high standard, as may be seen among the numerous examples of his portraits in the Rijks Museum. They mostly belong to his later period. The best is the earliest one, painted in 1657, representing the _Six Governors of the Huiszittenhuis_, seated round a table in black clothes and steeple hats. The heads are well characterized and the flesh-tones luminous; but an air of attitudinizing pervades the assemblage, which has rather the prim, set manner of a photographic group. And much the same feeling is aroused by the _Four Governors of the Leper House_, which is considered in Holland his masterpiece. In fact, it is not in the formal arrangement of a corporation picture, but in a single figure, that Bol is seen to best advantage. Yet some of the examples of these in the Rijks Museum, such as the _Roelof Meulenaar_ and _Maria Rey_, are commonplace parodies of Rembrandt’s manner, while that of the sculptor _Artus Quellinus_ is a parody of Van Dyck’s elegance. Bol, in fact, was an able assimilator of his master, Rembrandt, and as long as he retained the enthusiasm of his youth, painted creditable and often excellent portraits. Later, however, he drifted into the swim of social decadence, and his work is characterized by affectation, vapidity, and perfunctoriness.