a
particular disease.

IMMUNIZE.--To render immune.

INCUBATION.--The interval between exposure to an infectious disease and
the first appearance of symptoms.

INFECT.--To communicate disease germs.

INFECTION.--An agent by which disease may be communicated from one
individual to another; also, an infectious disease.

INOCULATE.--To introduce any biological product directly into the
tissues of the body.

INOCULATION.--The process of inoculating.

INTESTINAL TRACT.--The small and large intestines.

M

MICROBE.--See _Germ_.

MICRO-ORGANISM.--See _Germ_.

MUCUS.--The substance secreted by mucous membranes.

MUCOUS MEMBRANES.--The membranes lining certain cavities of the body,
especially the digestive and respiratory tracts.

N

NUTRIENT.--One of several chemical groups to which the essential
constituents of food belong.

O

ORGANIC.--Derived from or relating to an organism.

ORGANISM.--An individual that is or has been alive.

P

PARASITE.--An individual that lives in or upon another individual.

PASTEURIZATION.--The process of pasteurizing.

PASTEURIZE.--To subject milk to a temperature of 142 deg.-145 deg.
Fahrenheit for thirty minutes.

PATHOGENIC.--Disease-producing.

PERTUSSIS.--Whooping-cough.

PROTEID.--One of the complex nitrogenous substances constituting the
essential parts of animal and vegetable tissues.

PROTOZOON (pl. protozoa).--An animal organism composed of a single cell.

PUS.--The fluid product of inflammation; matter.

PUTREFACTION.--Decomposition of nitrogenous organic matter brought about
by micro-organisms and accompanied by a foul odor.

R

RESISTANCE.--See _Immunity_.

RESPIRATORY TRACT.--The air passages, including the nose, mouth, larynx,
trachea, bronchial tubes, and lungs.

S

SAPROPHYTE.--A vegetable organism that lives on decaying organic matter.

SARCINA.--Literally, a bundle. Applied to bacteria grouped in bundles or
packets.

SEPTIC.--Putrefying or decomposing; infected by pus-producing bacteria.

SEQUELA.--A disease or unhealthy condition following another disease or
unhealthy condition.

SERUM.--The fluid which separates from the clot after blood has
coagulated; especially, that containing an antitoxin.

SEWAGE.--Any substance containing urine or fecal matter; also, the
substance which passes through sewers.

SPIRILLUM (pl. spirilla).--A variety of bacteria having spirally twisted
cells.

SPORE.--A resting stage, charact