Finally, remember this, that whenever you have an hour to spare you should give thought to your studies, especially to the law books; for it is clear that those who gain knowledge from books have keener wits than others, since those who are the most learned have the best proofs for their knowledge. Make a study of all the laws, but while you remain a merchant there is no law that you will need to know more thoroughly than the Bjarkey code.[166] If you are acquainted with the law, you will not be annoyed by quibbles when you have suits to bring against men of your own class, but will be able to plead according to law in every case. Footnote 166: The “Birch-isle” code was originally a set of rules governing commercial intercourse. After a time it became a more elaborate law governing the municipality as well as the traders who were more or less permanently located there. It is believed that the name is derived from Birka, a trading center in eastern Sweden not far from the site of modern Stockholm. The “Birch-Isle” code is published in _Norges Gamle Love_, I, part iii, 303-336. But although I have most to say about laws, I regard no man perfect in knowledge unless he has thoroughly learned and mastered the customs of the place where he is sojourning. And if you wish to become perfect in knowledge, you must learn all the languages, first of all Latin and French, for these idioms are most widely used; and yet, do not neglect your native tongue or speech. ------------------------------------------------------------------------ IV THE SAME SUBJECT CONTINUED _Son._ May God reward you, sire, for the love of kinship that you show in pointing out so many things that I may find needful,—if I have the good fortune to learn them and to remember them after they are learned. And if you think there are any other important matters that ought to be taken up in this discussion, I shall be glad to listen attentively.