We must not forget, whilst we are on this subject, to make some remarks on his custom of painting by night, which confirms what I have already mentioned,--his great affection to his art; since he could not amuse himself in the evening by any other means so agreeable to himself. I am, indeed, much inclined to believe that it is a practice very advantageous and improving to an artist; for by this means he will acquire a new and a higher perception of what is great and beautiful in nature. By candle-light, not only objects appear more beautiful, but from their being in a greater breadth of light and shadow, as well as having a greater breadth and uniformity of colour, nature appears in a higher style; and even the flesh seems to take a higher and richer tone of colour. Judgment is to direct us in the use to be made of this method of study; but the method itself is, I am sure, advantageous. I have often imagined that the two great colourists, Titian and Correggio, though I do not know that they painted by night, formed their high ideas of colouring from the effects of objects by this artificial light; but I am more assured that whoever attentively studies the first and best manner of Guercino, will be convinced that he either painted by this light, or formed his manner on this conception. Another practice Gainsborough had, which is worth mentioning, as it is certainly worthy of imitation; I mean his manner of forming all the parts of his picture together; the whole going on at the same time, in the same manner as nature creates her works. Though this method is not uncommon to those who have been regularly educated, yet probably it was suggested to him by his own natural sagacity. That this custom is not universal appears from the practice of a painter whom I have just mentioned, Pompeio Battoni, who finished his historical pictures part after part, and in his portraits completely finished one feature before he proceeded to another. The consequence was as might be expected; the countenance was never well expressed; and, as the painters say, the whole was not well put together.