If you're interested in chemistry you can find an interesting information in Periodic Tables of the Elements in Over One Hundred Languages. This is an on-line dictionary where you can find, first of all, a copy of Mendeleev's Periodic Table of the Elements and, secondly, a very usefull and interesting information about these elements. For example, I've just found there some facts about my favourite chemical elements. They are mercury and silver (Hydrargyrum and Argentum). I've found about their description, quality, with what other chemical elements they can interact, about their history, where they can be used now and many other things. Besides, this on-line dictionary not just English. You can find information written in many different languages