CACHAO, a province of the kingdom of Tonquin in Asia, situated in the heart of the kingdom, and surrounded by the other seven. Its soil is fertile, and in some places mountainous, abounding with variety of trees, and particularly that of varnish. Most of these provinces carry on some branch of the silk manufacture, but this most of all. It takes its name from the capital, which is also the metropolis of the whole kingdom, though in other respects hardly comparable to a Chinese one of the third rank.