On Rickets 305 



indisposition to work and exercise ; for the children 

 •can only play sitting, and can scarcely stand on their 

 feet ; and at last, as the disease advances, the weak 

 neck can hardly sustain the weight of the head. 



Such and so many are the symptoms of this 

 disease ; we have next to consider what is the evil 

 which is the fruitful parent of this numerous brood. 



And in the first place we assume that the cause of 

 this disease does not consist in the access of vitiated 

 blood from the heart ; for in this case the whole 

 mass of the blood would be corrupted, and as this is 

 indiscriminately distributed to all parts, the impure 

 blood would affect all parts equally ; but this never 

 happens in this disease. For the head, as also the 

 viscera, except that they are larger than usual, are 

 healthy ; indeed the very parenchymata, which chiefly 

 consist of affused blood, inasmuch as they closely 

 resemble those of healthy persons, testify that the 

 blood is sound : for it is absurd to assume some sort 

 of elective attraction in virtue of which the head and 

 the other healthy organs attract what is good in the 

 blood, but send away the bad blood to other parts : 

 for this attraction, if it existed, would be present 

 €qually in all parts, as there is the same congruence 

 with good blood and need of it in all parts ; and this 

 is what is supposed to produce motion of this sort. 



Secondly, we assert that the origin of this affection 

 does not consist in a depraved constitution of the 

 parts themselves, as if parts suffering from intem- 

 perate cold and moisture were unfit to receive the 

 blood coming from the heart : for whence arises such 

 excessive moisture and coldness of some parts, when 

 all are similarly and equally irrigated by the spirits 

 of the warming blood ? Nor do I think coldness 

 innate in the parts, but in them over and above their 



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