i think it was in a V.S.Niapaul (sp.?) book-- that there is a short side essay on 'trade' (maybe in Bend in the River?)in Africa/and the congo..it went on about how 'trading and markets in worked, and what was considered valualbe in the local markets.. how the people there loved steel, and enamaled pots and bowl, that didn't rust, were so durible, and easy to clean, and how they loved nailclippers..-- easier to use than scissors, smaller, and stronger, and do usefull for keeping ones nails clean and neat(there were other trade goods, too, that at first glance seemed odd, but that were also treasured)