Inflammation is a morbid process characterized by the presence of increased temperature and one or more of the symptoms, pain, redness, and swelling. It is distinguished from fever by being confined locally, while fever is a general functional disturbance showing elevation of temperature, increased katabolism, decreased secretion, etc. Our clinical experience with fevers leads us to accept Metchnikoff’s conclusion that the essential phenomenon of inflammation is hyperaemia. Upon the hyperaemia depend the swelling, pain, and local increase in heat-production. Hyperaemia in turn depends upon disturbance of the vasomotor nerves either as a direct result of some local subluxation or as an indirect consequence of local irritation. A newly acquired subluxation produces an acute irritation of the pre-ganglionic axons which connect the spinal nerves with the sympathetic ganglia. If these ganglia send out post-ganglionic axons which are vaso-motor in function, an inflammation may be produced without the intervention of any secondary cause. On the other hand, there may be a subluxation producing weakness of some part; through injury to that part or the introduction of poisons or irritants such as germ infection, sensory end-organs are affected and the motor reaction which follows increases the subluxation; this slight increase produces acute irritation of the nerve and hyperaemia, with its resultant phenomena, follows. Stated briefly, irritants produce inflammation only by acting through the medium of the spine. If the spine be normal these irritants are insufficient to produce morbid process. Local inflammation tends to develop toxins, especially if it be of bacterial origin, which may in turn affect the entire organism--an effect which will be discussed presently. Exception must be made in those traumatic cases in which hyperaemia is essential to the reparatory process, and which are attended by what may be termed a normally increased heat-production. This beneficent and reparatory condition cannot be termed disease or morbid process.