Dr. Sydenham, a sworn Enemy to all Theories, learn'd thus much from downright Observation; and gives this reason why Autumnal Quartans hold six Months, because by computation the Fits of so long a time amount to 336 hours, or 14 days, the period of a continual Fever of the same Season.[43]
So Galen takes notice that when an Exquisite Tertian is terminated in seven Paroxysms, a true Continual at the same time has its Crisis in seven days; that is, the Fever lasts as long in one as in the other, in as much (says he) as a Fit in an Intermitting Feaver answers to a day in a Continual[44]. Now this so comes to pass, because
- In these Cases there is always a Fermentation in the Blood, which goes not off till the active Particles are thrown out by those Organs of Secretion, which, according to the Laws of Motion, are most fitted to separate 'em. And
- As different Liquors put upon a Ferment, are depurated in different times, so the Arterial Fluid takes up a determined Period, of which it is discharged of an induced Effervescence.
- The Symptoms, during this Ebullition, do not proceed all along in the same Tenour; but on some days particularly, they give such evident Marks of their good or bad Quality, that the nature of the ensuing Solution may very well be guess'd at, and foretold by 'em.
Things being thus, Those days on which the Disease was so evidently terminated one way or other, might very justly be call'd the days of Crisis; and those upon which the tendency of Illness was discovered by most visible Tokens, the Indices of the Critical Days.
And thus far the Foundation was good, but when a false Theory happen'd unluckily to be joined to true Observations, this did a little puzzle the Cause. Hippocrates , it is plain, knew not to what to ascribe