 Putative examples of kinds may be found in all scientific disciplines. Chemistry provides what are taken by many to be the paradigm examples of kinds, the chemical elements, while chemical compounds, such as H2O, are also natural kinds of stuff. (Instances of a natural kind may be man-made, such as artificially synthesized ascorbic acid, i.e., vitamin C; but whether chemical kinds all of whose instances are artificial are natural kinds is open to debate. The synthetic transuranium elements, e.g. Rutherfordium, seem good candidates for natural kinds, whereas artificial chemical kinds, such as the entirely synthetic compound bismuth germanate, Bi4Ge3OO12, which is used in particle detectors, are, arguably, less obviously natural kinds.) The standard model in quantum physics reveals many kinds of fundamental particles (electron, tau neutrino, charm quark), plus broader categories such as kinds of kind (lepton, quark) and higher kinds (fermion, boson). Astronomy classifies the heavenly bodies: galaxies, for example, can be either elliptical, lenticular, or spiral.