He produced pictures in 1641–1642 on the lines of his brother – amongst these, the Five Senses, which Adrian afterwards represented by a Man reading a Paper, a Peasant tasting Beer, a Rustic smearing his Sores with Ointment and a Countryman sniffing at a Snuff-box.
A specimen of Isaac's work at this period may be seen in the Laughing Boor with a Pot of Beer, in the museum of Amsterdam; the cottage interior, with two peasants and three children near a fire, in the Berlin museum; a Concert, with people listening to singers accompanied by a piper and flute player, and a Boor stealing a Kiss from a Woman, in the Lacaze collection at the Louvre.
[1] Isaac's progress in his new path was greatly facilitated by his previous experience as a figure painter; and, although he now selected his subjects either from village high streets or frozen canals, he gave fresh life to the scenes by depicting animated groups of people with a refined and searching study of picturesque contrasts.
[1] The first manifestation of Isaac's surrender of Adriaen's style is apparent in 1644 when the skating and sledging scenes were executed which we see in the Lacaze collection and the galleries of the Hermitage, Antwerp and Lille.
[1] These quirks are overcome by his broad contrasts of light and shade and the masterly figures of horses, riders, travellers, rustics, quarrelling children, dogs, poultry and cattle.
The absence of foliage, the crisp atmosphere and the calm air of cold January days, unsullied by smoke or vapour, preclude the use of the brown tinge, and leave the painter no choice but to ring the changes with a great variety of opal tints.