1056 CONDITION OF THE BLOOD IN THE 



off in a very short time after the circulation and 

 activity of the emunctories have been restored, 

 by which the blood is depurated ; and does not 

 return again without a repetition of the exciting 

 cause, for the obvious reason that the blood has 

 returned to its natural state. 



But if an individual be exposed for some time 

 to malaria of sufficient intensity to impair the 

 vital properties of the blood in a mitigated degree, 

 and then to a shower of rain, or some other ex- 

 citing cause calculated to bring on a chill, the 

 latter continues for a longer or shorter period, 

 according as the vital properties of the blood 

 have been previously more or less deranged, 

 which depends on the duration or intensity of 

 the predisposing causes. When these have been 

 moderate, the cold stage lasts for one or two 

 hours, because the vital heat obtained by respi- 

 ration continues to unite the blood with the solids 

 for some time after the chill has commenced : 

 yet as the blood becomes sufficiently deranged 

 during the stage of depression, to arrest or greatly 

 diminish the nutritive process, whatever amount 

 of heat is not transferred to the solids, accumu- 

 lates, and brings on the hot stage, which con- 

 tinues until the blood is restored to its former 

 state, when there is a complete intermission of 

 all the symptoms. But if the patient remain 

 exposed to the predisposing cause of the disease, 

 the paroxysm returns at stated intervals of one, 



