From the accession of new stimuli, or an increase in the force of former ones, this typhus state of fever sometimes assumes, on the 11th, 14th, and even 20th days, the symptoms of the synocha state of fever. It will be useful to remember this remark, not only because it establishes the unity of fever, but because it will justify the use of a remedy, seldom prescribed after the disease has acquired that name which associates it with stimulating medicines. The common name of this state of fever, is the _nervous_ fever. This name is improper; for it invades the nervous system by pain, delirium, and convulsions much less than several other states of fever. To prevent the absurd and often fatal association of ideas upon the treatment of this state of fever, I have called it, from its duration, the _low chronic_ state of fever. I have adopted the term _low_, from Dr. Butter's account of the remitting fever of children, in order to distinguish it from states of fever to be mentioned hereafter, in which the patient is not confined to his bed. This new name of the typhus or nervous fever establishes its analogy with several other diseases. We have the acute and the chronic rheumatism; the acute and chronic pneumony, commonly called the pleurisy and pulmonary consumption; the acute and chronic inflammation of the brain, known unfortunately by the unrelated names of phrenitis, madness, and internal dropsy of the brain. Why should we hesitate, in like manner, in admitting acute and chronic fever, in all those cases where no local inflammation attends? 8. The _typhoid_ state of fever is composed of the synocha and low chronic states of fever. It is the _slow_ nervous fever of Dr. Butter. The excitement of the blood-vessels is somewhat greater than in the _low_ chronic state of fever. Perhaps the muscular fibres of the blood-vessels, in this state of fever, are affected by different degrees of stimulus and excitement. Supposing a pulse to consist of eight cords, I think I have frequently felt more or less of them tense or relaxed, according as the fever partook more or less of the synocha, or low chronic states of fever. This state of fever occurs most frequently in what are called the hectic and puerperal fevers, and in the scarlatina. 9. The _hectic_ state of fever differs from all the other states of fever, by the want of regularity in its paroxysms, in which chills, fevers, and sweats are included; and by the brain, nerves, muscles, and alimentary canal being but little impaired in their functions by it. It appears to be an exclusive disease of the blood-vessels. It occurs in the pulmonary consumption, in some cases of lues, of scrophula, and of the gout, and after most of the states of fever which have been described. The force of the pulse is various, being occasionally synochoid, typhoid, and typhus.