428 Dr. Young on the Ligature of the Carotid Arteries. [Jcne, 



other, it might be sufficient to tie the artery of the affected side 

 only), and tliat the blood was forced into a longer and more 

 circuitous couise by the anastomosing branches ; the arteries 

 and veins may have lost their natural tone and calibre, and 

 eventually no doubt the anastomosing branches themselves 

 •would become expanded and enlarged so as to admit as much 

 blood to the brain as formerly ; yet the tortuous course of the 

 arteries would probably much diminish the vis a tergo, and 

 deaden the impulse of the blood coming from the heart ; so that 

 a powerfully co-operating remedy might be obtained in addition 

 to those generally used. 



Of late, the operation of tying the carotids for aneurism has 

 been successfully employed. I have not the advantage myself 

 of knowing what phenomena have resulted from the operation 

 with respect to the circulation of the blood in the head. As I 

 believe it is a rule not to perform the operation until the anasto- 

 mosing branches are sufficiently expanded to carry on the circu- 

 lation, after the main artery has been closed, the case will not 

 be in point ; but probably much might be learned from an 

 attentive observance of sucii cases. It is very rash to form a 

 priori conclusions upon the eftects of operations which have 

 never been performed, more especially where so dehcate and 

 mysterious an organ as the brain is concerned. It is likely, 

 however, that if both carotids were tied even where an inordi- 

 nate distension of the blood-vessels of the brain had before 

 occurred, that the flow of blood would at first be so much 

 impeded that the patient might fall into the opposite ex.treme, 

 and that fainting, or some affection arising fioni the presence of 

 too small a quantity of blood in the head, would supervene. 

 But this evil would only be temporary; and there are fortunately 

 plenty of remedies for it much more efficacious than those now 

 in use for the opposite affection. As most nervous diseases are 

 supposed either to be connected with, or produced or aggravated 

 by, a determination of blood to the head, I hope we may at 

 length be enabltd to discover some adequate means of sub- 

 duing and keeping down these obstinate and untractable 

 maladies. 



