CIRCULATION OF THE BLOOD. 117 



suppose that there are good and evil spirits that roam about or 

 possess the body, that assist or cast obstacles in the way. They 

 hold some diseases to be owing to a Cacodaemon or evil spirit, 

 as there are others that are due to a cacochemy or defective 

 assimilation. 



Although there is nothing more uncertain and question- 

 able, then, than the doctrine of spirits that is proposed to us, 

 nevertheless physicians seem for the major part to conclude, 

 with Hippocrates, that our body is composed or made up of 

 three elements, viz., containing parts, contained parts, and 

 causes of action, spirits being understood by the latter term. 

 But if spirits are to be taken as synonymous with causes of ac- 

 tivity, whatever has power in the living body and a faculty of 

 action must be included under the denomination. It would 

 appear, therefore, that all spirits were neither aereal sub- 

 stances, nor powers, nor habits; and that all were not in- 

 corporeal. 



But keeping in view the points that especially interest us, 

 others, as leading to tediousness, being left unnoticed, it seems 

 that the spirits which flow by the veins or the arteries are not 

 distinct from the blood, any more than the flame of a lamp is 

 distinct from the inflammable vapour that is on fire ; in short, 

 that the blood and these spirits signify one and the same thing, 

 though different, like generous wine and its spirit; for as 

 wine, when it has lost all its spirit, is no longer wine, but a 

 vapid liquor or vinegar ; so blood without spirit is not blood, but 

 something else clot or cruor ; even as a hand of stone, or of a 

 dead body, is no hand in the most complete sense, neither is 

 blood void of the vital principle proper blood ; it is immediately 

 to be held as corrupt when deprived of its spirit. The spirit 

 therefore which inheres in the arteries, and especially in the 

 blood which fills them, is to be regarded either as its act or 

 agent, in the same way as the spirit of wine in wine, and the 

 spirit of aqua vitse in brandy, or as a flame kindled in alcohol, 

 which lives and feeds on, or is nourished by itself. The blood con- 

 sequently, though richly imbued with spirits, does not swell, nor 

 ferment, nor rise to a head through them, so as to require and 

 occupy a larger space, a fact that may be ascertained beyond 

 the possibility of question by the two cups of equal size ; it is 

 to be regarded as wine, possessed of a large amount of spirits, 



