Inoculation is the placement of something to where it will grow or reprouce, and is most commonly used in respect of the introduction of a serum, vaccine, or antigenic substance into the body of a human or animal, especially to produce or boost immunity to a specific disease; but also can be used to refer to the communication of a disease to a living organism by transferring its causative agent into the organism, to implant microorganisms or infectious material into a culture medium such as a brewers vat or a petri dish, to safeguard as if by inoculation, to introduce an idea or attitude into someone's mind, any placement of microorganisms or viruses at a site where infection is possible such as to increase soybeans' nitrogen fixation one can treat soybeans at planting with Rhizobium japonicum inoculant. The verb "to inoculate" is from Middle English "inoculaten", which meant "to graft a scion (a scion is a plant part to be grafted onto another plant); which in turn is from Latin "inoculare", past participle "inoculat-".