 On account of the problems for natural kinds in biology as well as the development of modern chemistry, chemical kinds have replaced biological kinds as the paradigms of natural kinds. The chemical elements and chemical compounds appear to be bona fide natural kinds. We refer to chemical kinds in laws, explanations, and inductions: that a certain item is iron explains its behaviour and that behaviour is predictable; that iron objects are magnetizable is a law of nature (criteria 2 and 3 above). Moreover, we can induce that all iron is magnetizable, from the observation of particular instances of iron objects that are magnetic. And chemical kinds appear to obey the categorical distinctness requirement: iron is clearly distinct from its neighbours in the periodic table (manganese and cobalt); no elements are intermediate kinds (criterion 6 above). Furthermore, microstructural essentialism seems to be a prima facie plausible option for chemical kinds: it is essential to iron that something made of pure iron is constituted by atoms that have precisely 26 protons in their nuclei.